// SPDX-License-Identifier: GPL-2.0
#include <linux/acpi.h>
#include <linux/array_size.h>
#include <linux/bitmap.h>
#include <linux/cleanup.h>
#include <linux/compat.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/idr.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/lockdep.h>
#include <linux/module.h>
#include <linux/nospec.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/srcu.h>
#include <linux/string.h>
#include <linux/gpio.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <uapi/linux/gpio.h>
#include "gpiolib-acpi.h"
#include "gpiolib-cdev.h"
#include "gpiolib-of.h"
#include "gpiolib-swnode.h"
#include "gpiolib-sysfs.h"
#include "gpiolib.h"
#define CREATE_TRACE_POINTS
#include <trace/events/gpio.h>
/* Implementation infrastructure for GPIO interfaces.
*
* The GPIO programming interface allows for inlining speed-critical
* get/set operations for common cases, so that access to SOC-integrated
* GPIOs can sometimes cost only an instruction or two per bit.
*/
/* Device and char device-related information */
static DEFINE_IDA(gpio_ida);
static dev_t gpio_devt;
#define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */
static int gpio_bus_match(struct device *dev, const struct device_driver *drv)
{
struct fwnode_handle *fwnode = dev_fwnode(dev);
/*
* Only match if the fwnode doesn't already have a proper struct device
* created for it.
*/
if (fwnode && fwnode->dev != dev)
return 0;
return 1;
}
static const struct bus_type gpio_bus_type = {
.name = "gpio",
.match = gpio_bus_match,
};
/*
* Number of GPIOs to use for the fast path in set array
*/
#define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT
static DEFINE_MUTEX(gpio_lookup_lock);
static LIST_HEAD(gpio_lookup_list);
static LIST_HEAD(gpio_devices);
/* Protects the GPIO device list against concurrent modifications. */
static DEFINE_MUTEX(gpio_devices_lock);
/* Ensures coherence during read-only accesses to the list of GPIO devices. */
DEFINE_STATIC_SRCU(gpio_devices_srcu);
static DEFINE_MUTEX(gpio_machine_hogs_mutex);
static LIST_HEAD(gpio_machine_hogs);
const char *const gpio_suffixes[] = { "gpios", "gpio", NULL };
static void gpiochip_free_hogs(struct gpio_chip *gc);
static int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key);
static void gpiochip_irqchip_remove(struct gpio_chip *gc);
static int gpiochip_irqchip_init_hw(struct gpio_chip *gc);
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc);
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc);
static bool gpiolib_initialized;
const char *gpiod_get_label(struct gpio_desc *desc)
{
struct gpio_desc_label *label;
unsigned long flags;
flags = READ_ONCE(desc->flags);
label = srcu_dereference_check(desc->label, &desc->gdev->desc_srcu,
srcu_read_lock_held(&desc->gdev->desc_srcu));
if (test_bit(FLAG_USED_AS_IRQ, &flags))
return label ? label->str : "interrupt";
if (!test_bit(FLAG_REQUESTED, &flags))
return NULL;
return label ? label->str : NULL;
}
static void desc_free_label(struct rcu_head *rh)
{
kfree(container_of(rh, struct gpio_desc_label, rh));
}
static int desc_set_label(struct gpio_desc *desc, const char *label)
{
struct gpio_desc_label *new = NULL, *old;
if (label) {
new = kzalloc(struct_size(new, str, strlen(label) + 1),
GFP_KERNEL);
if (!new)
return -ENOMEM;
strcpy(new->str, label);
}
old = rcu_replace_pointer(desc->label, new, 1);
if (old)
call_srcu(&desc->gdev->desc_srcu, &old->rh, desc_free_label);
return 0;
}
/**
* gpio_to_desc - Convert a GPIO number to its descriptor
* @gpio: global GPIO number
*
* Returns:
* The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO
* with the given number exists in the system.
*/
struct gpio_desc *gpio_to_desc(unsigned gpio)
{
struct gpio_device *gdev;
scoped_guard(srcu, &gpio_devices_srcu) {
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
if (gdev->base <= gpio &&
gdev->base + gdev->ngpio > gpio)
return &gdev->descs[gpio - gdev->base];
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(gpio_to_desc);
/* This function is deprecated and will be removed soon, don't use. */
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc,
unsigned int hwnum)
{
return gpio_device_get_desc(gc->gpiodev, hwnum);
}
/**
* gpio_device_get_desc() - get the GPIO descriptor corresponding to the given
* hardware number for this GPIO device
* @gdev: GPIO device to get the descriptor from
* @hwnum: hardware number of the GPIO for this chip
*
* Returns:
* A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given
* chip for the specified hardware number or %ENODEV if the underlying chip
* already vanished.
*
* The reference count of struct gpio_device is *NOT* increased like when the
* GPIO is being requested for exclusive usage. It's up to the caller to make
* sure the GPIO device will stay alive together with the descriptor returned
* by this function.
*/
struct gpio_desc *
gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum)
{
if (hwnum >= gdev->ngpio)
return ERR_PTR(-EINVAL);
return &gdev->descs[array_index_nospec(hwnum, gdev->ngpio)];
}
EXPORT_SYMBOL_GPL(gpio_device_get_desc);
/**
* desc_to_gpio - convert a GPIO descriptor to the integer namespace
* @desc: GPIO descriptor
*
* This should disappear in the future but is needed since we still
* use GPIO numbers for error messages and sysfs nodes.
*
* Returns:
* The global GPIO number for the GPIO specified by its descriptor.
*/
int desc_to_gpio(const struct gpio_desc *desc)
{
return desc->gdev->base + (desc - &desc->gdev->descs[0]);
}
EXPORT_SYMBOL_GPL(desc_to_gpio);
/**
* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
* @desc: descriptor to return the chip of
*
* *DEPRECATED*
* This function is unsafe and should not be used. Using the chip address
* without taking the SRCU read lock may result in dereferencing a dangling
* pointer.
*
* Returns:
* Address of the GPIO chip backing this device.
*/
struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
{
if (!desc)
return NULL;
return gpio_device_get_chip(desc->gdev);
}
EXPORT_SYMBOL_GPL(gpiod_to_chip);
/**
* gpiod_to_gpio_device() - Return the GPIO device to which this descriptor
* belongs.
* @desc: Descriptor for which to return the GPIO device.
*
* This *DOES NOT* increase the reference count of the GPIO device as it's
* expected that the descriptor is requested and the users already holds a
* reference to the device.
*
* Returns:
* Address of the GPIO device owning this descriptor.
*/
struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc)
{
if (!desc)
return NULL;
return desc->gdev;
}
EXPORT_SYMBOL_GPL(gpiod_to_gpio_device);
/**
* gpio_device_get_base() - Get the base GPIO number allocated by this device
* @gdev: GPIO device
*
* Returns:
* First GPIO number in the global GPIO numberspace for this device.
*/
int gpio_device_get_base(struct gpio_device *gdev)
{
return gdev->base;
}
EXPORT_SYMBOL_GPL(gpio_device_get_base);
/**
* gpio_device_get_label() - Get the label of this GPIO device
* @gdev: GPIO device
*
* Returns:
* Pointer to the string containing the GPIO device label. The string's
* lifetime is tied to that of the underlying GPIO device.
*/
const char *gpio_device_get_label(struct gpio_device *gdev)
{
return gdev->label;
}
EXPORT_SYMBOL(gpio_device_get_label);
/**
* gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device
* @gdev: GPIO device
*
* Returns:
* Address of the GPIO chip backing this device.
*
* *DEPRECATED*
* Until we can get rid of all non-driver users of struct gpio_chip, we must
* provide a way of retrieving the pointer to it from struct gpio_device. This
* is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the
* chip can dissapear at any moment (unlike reference-counted struct
* gpio_device).
*
* Use at your own risk.
*/
struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev)
{
return rcu_dereference_check(gdev->chip, 1);
}
EXPORT_SYMBOL_GPL(gpio_device_get_chip);
/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
static int gpiochip_find_base_unlocked(u16 ngpio)
{
unsigned int base = GPIO_DYNAMIC_BASE;
struct gpio_device *gdev;
list_for_each_entry_srcu(gdev, &gpio_devices, list,
lockdep_is_held(&gpio_devices_lock)) {
/* found a free space? */
if (gdev->base >= base + ngpio)
break;
/* nope, check the space right after the chip */
base = gdev->base + gdev->ngpio;
if (base < GPIO_DYNAMIC_BASE)
base = GPIO_DYNAMIC_BASE;
if (base > GPIO_DYNAMIC_MAX - ngpio)
break;
}
if (base <= GPIO_DYNAMIC_MAX - ngpio) {
pr_debug("%s: found new base at %d\n", __func__, base);
return base;
} else {
pr_err("%s: cannot find free range\n", __func__);
return -ENOSPC;
}
}
/**
* gpiod_get_direction - return the current direction of a GPIO
* @desc: GPIO to get the direction of
*
* Returns:
* 0 for output, 1 for input, or an error code in case of error.
*
* This function may sleep if gpiod_cansleep() is true.
*/
int gpiod_get_direction(struct gpio_desc *desc)
{
unsigned long flags;
unsigned int offset;
int ret;
/*
* We cannot use VALIDATE_DESC() as we must not return 0 for a NULL
* descriptor like we usually do.
*/
if (IS_ERR_OR_NULL(desc))
return -EINVAL;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
offset = gpio_chip_hwgpio(desc);
flags = READ_ONCE(desc->flags);
/*
* Open drain emulation using input mode may incorrectly report
* input here, fix that up.
*/
if (test_bit(FLAG_OPEN_DRAIN, &flags) &&
test_bit(FLAG_IS_OUT, &flags))
return 0;
if (!guard.gc->get_direction)
return -ENOTSUPP;
ret = guard.gc->get_direction(guard.gc, offset);
if (ret < 0)
return ret;
/*
* GPIO_LINE_DIRECTION_IN or other positive,
* otherwise GPIO_LINE_DIRECTION_OUT.
*/
if (ret > 0)
ret = 1;
assign_bit(FLAG_IS_OUT, &flags, !ret);
WRITE_ONCE(desc->flags, flags);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_get_direction);
/*
* Add a new chip to the global chips list, keeping the list of chips sorted
* by range(means [base, base + ngpio - 1]) order.
*
* Returns:
* -EBUSY if the new chip overlaps with some other chip's integer space.
*/
static int gpiodev_add_to_list_unlocked(struct gpio_device *gdev)
{
struct gpio_device *prev, *next;
lockdep_assert_held(&gpio_devices_lock);
if (list_empty(&gpio_devices)) {
/* initial entry in list */
list_add_tail_rcu(&gdev->list, &gpio_devices);
return 0;
}
next = list_first_entry(&gpio_devices, struct gpio_device, list);
if (gdev->base + gdev->ngpio <= next->base) {
/* add before first entry */
list_add_rcu(&gdev->list, &gpio_devices);
return 0;
}
prev = list_last_entry(&gpio_devices, struct gpio_device, list);
if (prev->base + prev->ngpio <= gdev->base) {
/* add behind last entry */
list_add_tail_rcu(&gdev->list, &gpio_devices);
return 0;
}
list_for_each_entry_safe(prev, next, &gpio_devices, list) {
/* at the end of the list */
if (&next->list == &gpio_devices)
break;
/* add between prev and next */
if (prev->base + prev->ngpio <= gdev->base
&& gdev->base + gdev->ngpio <= next->base) {
list_add_rcu(&gdev->list, &prev->list);
return 0;
}
}
synchronize_srcu(&gpio_devices_srcu);
return -EBUSY;
}
/*
* Convert a GPIO name to its descriptor
* Note that there is no guarantee that GPIO names are globally unique!
* Hence this function will return, if it exists, a reference to the first GPIO
* line found that matches the given name.
*/
static struct gpio_desc *gpio_name_to_desc(const char * const name)
{
struct gpio_device *gdev;
struct gpio_desc *desc;
struct gpio_chip *gc;
if (!name)
return NULL;
guard(srcu)(&gpio_devices_srcu);
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (!gc)
continue;
for_each_gpio_desc(gc, desc) {
if (desc->name && !strcmp(desc->name, name))
return desc;
}
}
return NULL;
}
/*
* Take the names from gc->names and assign them to their GPIO descriptors.
* Warn if a name is already used for a GPIO line on a different GPIO chip.
*
* Note that:
* 1. Non-unique names are still accepted,
* 2. Name collisions within the same GPIO chip are not reported.
*/
static void gpiochip_set_desc_names(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
int i;
/* First check all names if they are unique */
for (i = 0; i != gc->ngpio; ++i) {
struct gpio_desc *gpio;
gpio = gpio_name_to_desc(gc->names[i]);
if (gpio)
dev_warn(&gdev->dev,
"Detected name collision for GPIO name '%s'\n",
gc->names[i]);
}
/* Then add all names to the GPIO descriptors */
for (i = 0; i != gc->ngpio; ++i)
gdev->descs[i].name = gc->names[i];
}
/*
* gpiochip_set_names - Set GPIO line names using device properties
* @chip: GPIO chip whose lines should be named, if possible
*
* Looks for device property "gpio-line-names" and if it exists assigns
* GPIO line names for the chip. The memory allocated for the assigned
* names belong to the underlying firmware node and should not be released
* by the caller.
*/
static int gpiochip_set_names(struct gpio_chip *chip)
{
struct gpio_device *gdev = chip->gpiodev;
struct device *dev = &gdev->dev;
const char **names;
int ret, i;
int count;
count = device_property_string_array_count(dev, "gpio-line-names");
if (count < 0)
return 0;
/*
* When offset is set in the driver side we assume the driver internally
* is using more than one gpiochip per the same device. We have to stop
* setting friendly names if the specified ones with 'gpio-line-names'
* are less than the offset in the device itself. This means all the
* lines are not present for every single pin within all the internal
* gpiochips.
*/
if (count <= chip->offset) {
dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n",
count, chip->offset);
return 0;
}
names = kcalloc(count, sizeof(*names), GFP_KERNEL);
if (!names)
return -ENOMEM;
ret = device_property_read_string_array(dev, "gpio-line-names",
names, count);
if (ret < 0) {
dev_warn(dev, "failed to read GPIO line names\n");
kfree(names);
return ret;
}
/*
* When more that one gpiochip per device is used, 'count' can
* contain at most number gpiochips x chip->ngpio. We have to
* correctly distribute all defined lines taking into account
* chip->offset as starting point from where we will assign
* the names to pins from the 'names' array. Since property
* 'gpio-line-names' cannot contains gaps, we have to be sure
* we only assign those pins that really exists since chip->ngpio
* can be different of the chip->offset.
*/
count = (count > chip->offset) ? count - chip->offset : count;
if (count > chip->ngpio)
count = chip->ngpio;
for (i = 0; i < count; i++) {
/*
* Allow overriding "fixed" names provided by the GPIO
* provider. The "fixed" names are more often than not
* generic and less informative than the names given in
* device properties.
*/
if (names[chip->offset + i] && names[chip->offset + i][0])
gdev->descs[i].name = names[chip->offset + i];
}
kfree(names);
return 0;
}
static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc)
{
unsigned long *p;
p = bitmap_alloc(gc->ngpio, GFP_KERNEL);
if (!p)
return NULL;
/* Assume by default all GPIOs are valid */
bitmap_fill(p, gc->ngpio);
return p;
}
static void gpiochip_free_mask(unsigned long **p)
{
bitmap_free(*p);
*p = NULL;
}
static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc)
{
struct device *dev = &gc->gpiodev->dev;
int size;
/* Format is "start, count, ..." */
size = device_property_count_u32(dev, "gpio-reserved-ranges");
if (size > 0 && size % 2 == 0)
return size;
return 0;
}
static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc)
{
struct device *dev = &gc->gpiodev->dev;
unsigned int size;
u32 *ranges;
int ret;
size = gpiochip_count_reserved_ranges(gc);
if (size == 0)
return 0;
ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL);
if (!ranges)
return -ENOMEM;
ret = device_property_read_u32_array(dev, "gpio-reserved-ranges",
ranges, size);
if (ret) {
kfree(ranges);
return ret;
}
while (size) {
u32 count = ranges[--size];
u32 start = ranges[--size];
if (start >= gc->ngpio || start + count > gc->ngpio)
continue;
bitmap_clear(gc->valid_mask, start, count);
}
kfree(ranges);
return 0;
}
static int gpiochip_init_valid_mask(struct gpio_chip *gc)
{
int ret;
if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask))
return 0;
gc->valid_mask = gpiochip_allocate_mask(gc);
if (!gc->valid_mask)
return -ENOMEM;
ret = gpiochip_apply_reserved_ranges(gc);
if (ret)
return ret;
if (gc->init_valid_mask)
return gc->init_valid_mask(gc,
gc->valid_mask,
gc->ngpio);
return 0;
}
static void gpiochip_free_valid_mask(struct gpio_chip *gc)
{
gpiochip_free_mask(&gc->valid_mask);
}
static int gpiochip_add_pin_ranges(struct gpio_chip *gc)
{
/*
* Device Tree platforms are supposed to use "gpio-ranges"
* property. This check ensures that the ->add_pin_ranges()
* won't be called for them.
*/
if (device_property_present(&gc->gpiodev->dev, "gpio-ranges"))
return 0;
if (gc->add_pin_ranges)
return gc->add_pin_ranges(gc);
return 0;
}
bool gpiochip_line_is_valid(const struct gpio_chip *gc,
unsigned int offset)
{
/* No mask means all valid */
if (likely(!gc->valid_mask))
return true;
return test_bit(offset, gc->valid_mask);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_valid);
static void gpiodev_release(struct device *dev)
{
struct gpio_device *gdev = to_gpio_device(dev);
/* Call pending kfree()s for descriptor labels. */
synchronize_srcu(&gdev->desc_srcu);
cleanup_srcu_struct(&gdev->desc_srcu);
ida_free(&gpio_ida, gdev->id);
kfree_const(gdev->label);
kfree(gdev->descs);
cleanup_srcu_struct(&gdev->srcu);
kfree(gdev);
}
static const struct device_type gpio_dev_type = {
.name = "gpio_chip",
.release = gpiodev_release,
};
#ifdef CONFIG_GPIO_CDEV
#define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt))
#define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev))
#else
/*
* gpiolib_cdev_register() indirectly calls device_add(), which is still
* required even when cdev is not selected.
*/
#define gcdev_register(gdev, devt) device_add(&(gdev)->dev)
#define gcdev_unregister(gdev) device_del(&(gdev)->dev)
#endif
static int gpiochip_setup_dev(struct gpio_device *gdev)
{
struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev);
int ret;
device_initialize(&gdev->dev);
/*
* If fwnode doesn't belong to another device, it's safe to clear its
* initialized flag.
*/
if (fwnode && !fwnode->dev)
fwnode_dev_initialized(fwnode, false);
ret = gcdev_register(gdev, gpio_devt);
if (ret)
return ret;
ret = gpiochip_sysfs_register(gdev);
if (ret)
goto err_remove_device;
dev_dbg(&gdev->dev, "registered GPIOs %u to %u on %s\n", gdev->base,
gdev->base + gdev->ngpio - 1, gdev->label);
return 0;
err_remove_device:
gcdev_unregister(gdev);
return ret;
}
static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog)
{
struct gpio_desc *desc;
int rv;
desc = gpiochip_get_desc(gc, hog->chip_hwnum);
if (IS_ERR(desc)) {
chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__,
PTR_ERR(desc));
return;
}
rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags);
if (rv)
gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n",
__func__, gc->label, hog->chip_hwnum, rv);
}
static void machine_gpiochip_add(struct gpio_chip *gc)
{
struct gpiod_hog *hog;
mutex_lock(&gpio_machine_hogs_mutex);
list_for_each_entry(hog, &gpio_machine_hogs, list) {
if (!strcmp(gc->label, hog->chip_label))
gpiochip_machine_hog(gc, hog);
}
mutex_unlock(&gpio_machine_hogs_mutex);
}
static void gpiochip_setup_devs(void)
{
struct gpio_device *gdev;
int ret;
guard(srcu)(&gpio_devices_srcu);
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
ret = gpiochip_setup_dev(gdev);
if (ret)
dev_err(&gdev->dev,
"Failed to initialize gpio device (%d)\n", ret);
}
}
static void gpiochip_set_data(struct gpio_chip *gc, void *data)
{
gc->gpiodev->data = data;
}
/**
* gpiochip_get_data() - get per-subdriver data for the chip
* @gc: GPIO chip
*
* Returns:
* The per-subdriver data for the chip.
*/
void *gpiochip_get_data(struct gpio_chip *gc)
{
return gc->gpiodev->data;
}
EXPORT_SYMBOL_GPL(gpiochip_get_data);
int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev)
{
u32 ngpios = gc->ngpio;
int ret;
if (ngpios == 0) {
ret = device_property_read_u32(dev, "ngpios", &ngpios);
if (ret == -ENODATA)
/*
* -ENODATA means that there is no property found and
* we want to issue the error message to the user.
* Besides that, we want to return different error code
* to state that supplied value is not valid.
*/
ngpios = 0;
else if (ret)
return ret;
gc->ngpio = ngpios;
}
if (gc->ngpio == 0) {
chip_err(gc, "tried to insert a GPIO chip with zero lines\n");
return -EINVAL;
}
if (gc->ngpio > FASTPATH_NGPIO)
chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n",
gc->ngpio, FASTPATH_NGPIO);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_get_ngpios);
int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
struct gpio_device *gdev;
unsigned int desc_index;
int base = 0;
int ret = 0;
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
*/
gdev = kzalloc(sizeof(*gdev), GFP_KERNEL);
if (!gdev)
return -ENOMEM;
gdev->dev.type = &gpio_dev_type;
gdev->dev.bus = &gpio_bus_type;
gdev->dev.parent = gc->parent;
rcu_assign_pointer(gdev->chip, gc);
gc->gpiodev = gdev;
gpiochip_set_data(gc, data);
/*
* If the calling driver did not initialize firmware node,
* do it here using the parent device, if any.
*/
if (gc->fwnode)
device_set_node(&gdev->dev, gc->fwnode);
else if (gc->parent)
device_set_node(&gdev->dev, dev_fwnode(gc->parent));
gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL);
if (gdev->id < 0) {
ret = gdev->id;
goto err_free_gdev;
}
ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id);
if (ret)
goto err_free_ida;
if (gc->parent && gc->parent->driver)
gdev->owner = gc->parent->driver->owner;
else if (gc->owner)
/* TODO: remove chip->owner */
gdev->owner = gc->owner;
else
gdev->owner = THIS_MODULE;
ret = gpiochip_get_ngpios(gc, &gdev->dev);
if (ret)
goto err_free_dev_name;
gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL);
if (!gdev->descs) {
ret = -ENOMEM;
goto err_free_dev_name;
}
gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL);
if (!gdev->label) {
ret = -ENOMEM;
goto err_free_descs;
}
gdev->ngpio = gc->ngpio;
gdev->can_sleep = gc->can_sleep;
scoped_guard(mutex, &gpio_devices_lock) {
/*
* TODO: this allocates a Linux GPIO number base in the global
* GPIO numberspace for this chip. In the long run we want to
* get *rid* of this numberspace and use only descriptors, but
* it may be a pipe dream. It will not happen before we get rid
* of the sysfs interface anyways.
*/
base = gc->base;
if (base < 0) {
base = gpiochip_find_base_unlocked(gc->ngpio);
if (base < 0) {
ret = base;
base = 0;
goto err_free_label;
}
/*
* TODO: it should not be necessary to reflect the
* assigned base outside of the GPIO subsystem. Go over
* drivers and see if anyone makes use of this, else
* drop this and assign a poison instead.
*/
gc->base = base;
} else {
dev_warn(&gdev->dev,
"Static allocation of GPIO base is deprecated, use dynamic allocation.\n");
}
gdev->base = base;
ret = gpiodev_add_to_list_unlocked(gdev);
if (ret) {
chip_err(gc, "GPIO integer space overlap, cannot add chip\n");
goto err_free_label;
}
}
for (desc_index = 0; desc_index < gc->ngpio; desc_index++)
gdev->descs[desc_index].gdev = gdev;
BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier);
BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier);
ret = init_srcu_struct(&gdev->srcu);
if (ret)
goto err_remove_from_list;
ret = init_srcu_struct(&gdev->desc_srcu);
if (ret)
goto err_cleanup_gdev_srcu;
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif
if (gc->names)
gpiochip_set_desc_names(gc);
ret = gpiochip_set_names(gc);
if (ret)
goto err_cleanup_desc_srcu;
ret = gpiochip_init_valid_mask(gc);
if (ret)
goto err_cleanup_desc_srcu;
for (desc_index = 0; desc_index < gc->ngpio; desc_index++) {
struct gpio_desc *desc = &gdev->descs[desc_index];
if (gc->get_direction && gpiochip_line_is_valid(gc, desc_index)) {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->get_direction(gc, desc_index));
} else {
assign_bit(FLAG_IS_OUT,
&desc->flags, !gc->direction_input);
}
}
ret = of_gpiochip_add(gc);
if (ret)
goto err_free_valid_mask;
ret = gpiochip_add_pin_ranges(gc);
if (ret)
goto err_remove_of_chip;
acpi_gpiochip_add(gc);
machine_gpiochip_add(gc);
ret = gpiochip_irqchip_init_valid_mask(gc);
if (ret)
goto err_free_hogs;
ret = gpiochip_irqchip_init_hw(gc);
if (ret)
goto err_remove_irqchip_mask;
ret = gpiochip_add_irqchip(gc, lock_key, request_key);
if (ret)
goto err_remove_irqchip_mask;
/*
* By first adding the chardev, and then adding the device,
* we get a device node entry in sysfs under
* /sys/bus/gpio/devices/gpiochipN/dev that can be used for
* coldplug of device nodes and other udev business.
* We can do this only if gpiolib has been initialized.
* Otherwise, defer until later.
*/
if (gpiolib_initialized) {
ret = gpiochip_setup_dev(gdev);
if (ret)
goto err_remove_irqchip;
}
return 0;
err_remove_irqchip:
gpiochip_irqchip_remove(gc);
err_remove_irqchip_mask:
gpiochip_irqchip_free_valid_mask(gc);
err_free_hogs:
gpiochip_free_hogs(gc);
acpi_gpiochip_remove(gc);
gpiochip_remove_pin_ranges(gc);
err_remove_of_chip:
of_gpiochip_remove(gc);
err_free_valid_mask:
gpiochip_free_valid_mask(gc);
err_cleanup_desc_srcu:
cleanup_srcu_struct(&gdev->desc_srcu);
err_cleanup_gdev_srcu:
cleanup_srcu_struct(&gdev->srcu);
err_remove_from_list:
scoped_guard(mutex, &gpio_devices_lock)
list_del_rcu(&gdev->list);
synchronize_srcu(&gpio_devices_srcu);
if (gdev->dev.release) {
/* release() has been registered by gpiochip_setup_dev() */
gpio_device_put(gdev);
goto err_print_message;
}
err_free_label:
kfree_const(gdev->label);
err_free_descs:
kfree(gdev->descs);
err_free_dev_name:
kfree(dev_name(&gdev->dev));
err_free_ida:
ida_free(&gpio_ida, gdev->id);
err_free_gdev:
kfree(gdev);
err_print_message:
/* failures here can mean systems won't boot... */
if (ret != -EPROBE_DEFER) {
pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__,
base, base + (int)gc->ngpio - 1,
gc->label ? : "generic", ret);
}
return ret;
}
EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key);
/**
* gpiochip_remove() - unregister a gpio_chip
* @gc: the chip to unregister
*
* A gpio_chip with any GPIOs still requested may not be removed.
*/
void gpiochip_remove(struct gpio_chip *gc)
{
struct gpio_device *gdev = gc->gpiodev;
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
gpiochip_free_hogs(gc);
scoped_guard(mutex, &gpio_devices_lock)
list_del_rcu(&gdev->list);
synchronize_srcu(&gpio_devices_srcu);
/* Numb the device, cancelling all outstanding operations */
rcu_assign_pointer(gdev->chip, NULL);
synchronize_srcu(&gdev->srcu);
gpiochip_irqchip_remove(gc);
acpi_gpiochip_remove(gc);
of_gpiochip_remove(gc);
gpiochip_remove_pin_ranges(gc);
gpiochip_free_valid_mask(gc);
/*
* We accept no more calls into the driver from this point, so
* NULL the driver data pointer.
*/
gpiochip_set_data(gc, NULL);
/*
* The gpiochip side puts its use of the device to rest here:
* if there are no userspace clients, the chardev and device will
* be removed, else it will be dangling until the last user is
* gone.
*/
gcdev_unregister(gdev);
gpio_device_put(gdev);
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
/**
* gpio_device_find() - find a specific GPIO device
* @data: data to pass to match function
* @match: Callback function to check gpio_chip
*
* Returns:
* New reference to struct gpio_device.
*
* Similar to bus_find_device(). It returns a reference to a gpio_device as
* determined by a user supplied @match callback. The callback should return
* 0 if the device doesn't match and non-zero if it does. If the callback
* returns non-zero, this function will return to the caller and not iterate
* over any more gpio_devices.
*
* The callback takes the GPIO chip structure as argument. During the execution
* of the callback function the chip is protected from being freed. TODO: This
* actually has yet to be implemented.
*
* If the function returns non-NULL, the returned reference must be freed by
* the caller using gpio_device_put().
*/
struct gpio_device *gpio_device_find(const void *data,
int (*match)(struct gpio_chip *gc,
const void *data))
{
struct gpio_device *gdev;
struct gpio_chip *gc;
/*
* Not yet but in the future the spinlock below will become a mutex.
* Annotate this function before anyone tries to use it in interrupt
* context like it happened with gpiochip_find().
*/
might_sleep();
guard(srcu)(&gpio_devices_srcu);
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
if (!device_is_registered(&gdev->dev))
continue;
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (gc && match(gc, data))
return gpio_device_get(gdev);
}
return NULL;
}
EXPORT_SYMBOL_GPL(gpio_device_find);
static int gpio_chip_match_by_label(struct gpio_chip *gc, const void *label)
{
return gc->label && !strcmp(gc->label, label);
}
/**
* gpio_device_find_by_label() - wrapper around gpio_device_find() finding the
* GPIO device by its backing chip's label
* @label: Label to lookup
*
* Returns:
* Reference to the GPIO device or NULL. Reference must be released with
* gpio_device_put().
*/
struct gpio_device *gpio_device_find_by_label(const char *label)
{
return gpio_device_find((void *)label, gpio_chip_match_by_label);
}
EXPORT_SYMBOL_GPL(gpio_device_find_by_label);
static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, const void *fwnode)
{
return device_match_fwnode(&gc->gpiodev->dev, fwnode);
}
/**
* gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding
* the GPIO device by its fwnode
* @fwnode: Firmware node to lookup
*
* Returns:
* Reference to the GPIO device or NULL. Reference must be released with
* gpio_device_put().
*/
struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode)
{
return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode);
}
EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode);
/**
* gpio_device_get() - Increase the reference count of this GPIO device
* @gdev: GPIO device to increase the refcount for
*
* Returns:
* Pointer to @gdev.
*/
struct gpio_device *gpio_device_get(struct gpio_device *gdev)
{
return to_gpio_device(get_device(&gdev->dev));
}
EXPORT_SYMBOL_GPL(gpio_device_get);
/**
* gpio_device_put() - Decrease the reference count of this GPIO device and
* possibly free all resources associated with it.
* @gdev: GPIO device to decrease the reference count for
*/
void gpio_device_put(struct gpio_device *gdev)
{
put_device(&gdev->dev);
}
EXPORT_SYMBOL_GPL(gpio_device_put);
/**
* gpio_device_to_device() - Retrieve the address of the underlying struct
* device.
* @gdev: GPIO device for which to return the address.
*
* This does not increase the reference count of the GPIO device nor the
* underlying struct device.
*
* Returns:
* Address of struct device backing this GPIO device.
*/
struct device *gpio_device_to_device(struct gpio_device *gdev)
{
return &gdev->dev;
}
EXPORT_SYMBOL_GPL(gpio_device_to_device);
#ifdef CONFIG_GPIOLIB_IRQCHIP
/*
* The following is irqchip helper code for gpiochips.
*/
static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
if (!girq->init_hw)
return 0;
return girq->init_hw(gc);
}
static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
struct gpio_irq_chip *girq = &gc->irq;
if (!girq->init_valid_mask)
return 0;
girq->valid_mask = gpiochip_allocate_mask(gc);
if (!girq->valid_mask)
return -ENOMEM;
girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio);
return 0;
}
static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
{
gpiochip_free_mask(&gc->irq.valid_mask);
}
static bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc,
unsigned int offset)
{
if (!gpiochip_line_is_valid(gc, offset))
return false;
/* No mask means all valid */
if (likely(!gc->irq.valid_mask))
return true;
return test_bit(offset, gc->irq.valid_mask);
}
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
/**
* gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip
* to a gpiochip
* @gc: the gpiochip to set the irqchip hierarchical handler to
* @irqchip: the irqchip to handle this level of the hierarchy, the interrupt
* will then percolate up to the parent
*/
static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc,
struct irq_chip *irqchip)
{
/* DT will deal with mapping each IRQ as we go along */
if (is_of_node(gc->irq.fwnode))
return;
/*
* This is for legacy and boardfile "irqchip" fwnodes: allocate
* irqs upfront instead of dynamically since we don't have the
* dynamic type of allocation that hardware description languages
* provide. Once all GPIO drivers using board files are gone from
* the kernel we can delete this code, but for a transitional period
* it is necessary to keep this around.
*/
if (is_fwnode_irqchip(gc->irq.fwnode)) {
int i;
int ret;
for (i = 0; i < gc->ngpio; i++) {
struct irq_fwspec fwspec;
unsigned int parent_hwirq;
unsigned int parent_type;
struct gpio_irq_chip *girq = &gc->irq;
/*
* We call the child to parent translation function
* only to check if the child IRQ is valid or not.
* Just pick the rising edge type here as that is what
* we likely need to support.
*/
ret = girq->child_to_parent_hwirq(gc, i,
IRQ_TYPE_EDGE_RISING,
&parent_hwirq,
&parent_type);
if (ret) {
chip_err(gc, "skip set-up on hwirq %d\n",
i);
continue;
}
fwspec.fwnode = gc->irq.fwnode;
/* This is the hwirq for the GPIO line side of things */
fwspec.param[0] = girq->child_offset_to_irq(gc, i);
/* Just pick something */
fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
fwspec.param_count = 2;
ret = irq_domain_alloc_irqs(gc->irq.domain, 1,
NUMA_NO_NODE, &fwspec);
if (ret < 0) {
chip_err(gc,
"can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n",
i, parent_hwirq,
ret);
}
}
}
chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__);
return;
}
static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
unsigned int *type)
{
/* We support standard DT translation */
if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) {
return irq_domain_translate_twocell(d, fwspec, hwirq, type);
}
/* This is for board files and others not using DT */
if (is_fwnode_irqchip(fwspec->fwnode)) {
int ret;
ret = irq_domain_translate_twocell(d, fwspec, hwirq, type);
if (ret)
return ret;
WARN_ON(*type == IRQ_TYPE_NONE);
return 0;
}
return -EINVAL;
}
static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d,
unsigned int irq,
unsigned int nr_irqs,
void *data)
{
struct gpio_chip *gc = d->host_data;
irq_hw_number_t hwirq;
unsigned int type = IRQ_TYPE_NONE;
struct irq_fwspec *fwspec = data;
union gpio_irq_fwspec gpio_parent_fwspec = {};
unsigned int parent_hwirq;
unsigned int parent_type;
struct gpio_irq_chip *girq = &gc->irq;
int ret;
/*
* The nr_irqs parameter is always one except for PCI multi-MSI
* so this should not happen.
*/
WARN_ON(nr_irqs != 1);
ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type);
if (ret)
return ret;
chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq);
ret = girq->child_to_parent_hwirq(gc, hwirq, type,
&parent_hwirq, &parent_type);
if (ret) {
chip_err(gc, "can't look up hwirq %lu\n", hwirq);
return ret;
}
chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq);
/*
* We set handle_bad_irq because the .set_type() should
* always be invoked and set the right type of handler.
*/
irq_domain_set_info(d,
irq,
hwirq,
gc->irq.chip,
gc,
girq->handler,
NULL, NULL);
irq_set_probe(irq);
/* This parent only handles asserted level IRQs */
ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec,
parent_hwirq, parent_type);
if (ret)
return ret;
chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n",
irq, parent_hwirq);
irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec);
/*
* If the parent irqdomain is msi, the interrupts have already
* been allocated, so the EEXIST is good.
*/
if (irq_domain_is_msi(d->parent) && (ret == -EEXIST))
ret = 0;
if (ret)
chip_err(gc,
"failed to allocate parent hwirq %d for hwirq %lu\n",
parent_hwirq, hwirq);
return ret;
}
static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc,
unsigned int offset)
{
return offset;
}
/**
* gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ
* @domain: The IRQ domain used by this IRQ chip
* @data: Outermost irq_data associated with the IRQ
* @reserve: If set, only reserve an interrupt vector instead of assigning one
*
* This function is a wrapper that calls gpiochip_lock_as_irq() and is to be
* used as the activate function for the &struct irq_domain_ops. The host_data
* for the IRQ domain must be the &struct gpio_chip.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
static int gpiochip_irq_domain_activate(struct irq_domain *domain,
struct irq_data *data, bool reserve)
{
struct gpio_chip *gc = domain->host_data;
unsigned int hwirq = irqd_to_hwirq(data);
return gpiochip_lock_as_irq(gc, hwirq);
}
/**
* gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ
* @domain: The IRQ domain used by this IRQ chip
* @data: Outermost irq_data associated with the IRQ
*
* This function is a wrapper that will call gpiochip_unlock_as_irq() and is to
* be used as the deactivate function for the &struct irq_domain_ops. The
* host_data for the IRQ domain must be the &struct gpio_chip.
*/
static void gpiochip_irq_domain_deactivate(struct irq_domain *domain,
struct irq_data *data)
{
struct gpio_chip *gc = domain->host_data;
unsigned int hwirq = irqd_to_hwirq(data);
return gpiochip_unlock_as_irq(gc, hwirq);
}
static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops)
{
ops->activate = gpiochip_irq_domain_activate;
ops->deactivate = gpiochip_irq_domain_deactivate;
ops->alloc = gpiochip_hierarchy_irq_domain_alloc;
/*
* We only allow overriding the translate() and free() functions for
* hierarchical chips, and this should only be done if the user
* really need something other than 1:1 translation for translate()
* callback and free if user wants to free up any resources which
* were allocated during callbacks, for example populate_parent_alloc_arg.
*/
if (!ops->translate)
ops->translate = gpiochip_hierarchy_irq_domain_translate;
if (!ops->free)
ops->free = irq_domain_free_irqs_common;
}
static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
{
struct irq_domain *domain;
if (!gc->irq.child_to_parent_hwirq ||
!gc->irq.fwnode) {
chip_err(gc, "missing irqdomain vital data\n");
return ERR_PTR(-EINVAL);
}
if (!gc->irq.child_offset_to_irq)
gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop;
if (!gc->irq.populate_parent_alloc_arg)
gc->irq.populate_parent_alloc_arg =
gpiochip_populate_parent_fwspec_twocell;
gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops);
domain = irq_domain_create_hierarchy(
gc->irq.parent_domain,
0,
gc->ngpio,
gc->irq.fwnode,
&gc->irq.child_irq_domain_ops,
gc);
if (!domain)
return ERR_PTR(-ENOMEM);
gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip);
return domain;
}
static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
{
return !!gc->irq.parent_domain;
}
int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc,
union gpio_irq_fwspec *gfwspec,
unsigned int parent_hwirq,
unsigned int parent_type)
{
struct irq_fwspec *fwspec = &gfwspec->fwspec;
fwspec->fwnode = gc->irq.parent_domain->fwnode;
fwspec->param_count = 2;
fwspec->param[0] = parent_hwirq;
fwspec->param[1] = parent_type;
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell);
int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc,
union gpio_irq_fwspec *gfwspec,
unsigned int parent_hwirq,
unsigned int parent_type)
{
struct irq_fwspec *fwspec = &gfwspec->fwspec;
fwspec->fwnode = gc->irq.parent_domain->fwnode;
fwspec->param_count = 4;
fwspec->param[0] = 0;
fwspec->param[1] = parent_hwirq;
fwspec->param[2] = 0;
fwspec->param[3] = parent_type;
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell);
#else
static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc)
{
return ERR_PTR(-EINVAL);
}
static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc)
{
return false;
}
#endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */
/**
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
* @d: the irqdomain used by this irqchip
* @irq: the global irq number used by this GPIO irqchip irq
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
*
* This function will set up the mapping for a certain IRQ line on a
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
* stored inside the gpiochip.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *gc = d->host_data;
int ret = 0;
if (!gpiochip_irqchip_irq_valid(gc, hwirq))
return -ENXIO;
irq_set_chip_data(irq, gc);
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key);
irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler);
/* Chips that use nested thread handlers have them marked */
if (gc->irq.threaded)
irq_set_nested_thread(irq, 1);
irq_set_noprobe(irq);
if (gc->irq.num_parents == 1)
ret = irq_set_parent(irq, gc->irq.parents[0]);
else if (gc->irq.map)
ret = irq_set_parent(irq, gc->irq.map[hwirq]);
if (ret < 0)
return ret;
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
*/
if (gc->irq.default_type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, gc->irq.default_type);
return 0;
}
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
{
struct gpio_chip *gc = d->host_data;
if (gc->irq.threaded)
irq_set_nested_thread(irq, 0);
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
static const struct irq_domain_ops gpiochip_domain_ops = {
.map = gpiochip_irq_map,
.unmap = gpiochip_irq_unmap,
/* Virtually all GPIO irqchips are twocell:ed */
.xlate = irq_domain_xlate_twocell,
};
static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc)
{
struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
struct irq_domain *domain;
domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first,
&gpiochip_domain_ops, gc);
if (!domain)
return ERR_PTR(-EINVAL);
return domain;
}
static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset)
{
struct irq_domain *domain = gc->irq.domain;
#ifdef CONFIG_GPIOLIB_IRQCHIP
/*
* Avoid race condition with other code, which tries to lookup
* an IRQ before the irqchip has been properly registered,
* i.e. while gpiochip is still being brought up.
*/
if (!gc->irq.initialized)
return -EPROBE_DEFER;
#endif
if (!gpiochip_irqchip_irq_valid(gc, offset))
return -ENXIO;
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
if (irq_domain_is_hierarchy(domain)) {
struct irq_fwspec spec;
spec.fwnode = domain->fwnode;
spec.param_count = 2;
spec.param[0] = gc->irq.child_offset_to_irq(gc, offset);
spec.param[1] = IRQ_TYPE_NONE;
return irq_create_fwspec_mapping(&spec);
}
#endif
return irq_create_mapping(domain, offset);
}
int gpiochip_irq_reqres(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
return gpiochip_reqres_irq(gc, hwirq);
}
EXPORT_SYMBOL(gpiochip_irq_reqres);
void gpiochip_irq_relres(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
gpiochip_relres_irq(gc, hwirq);
}
EXPORT_SYMBOL(gpiochip_irq_relres);
static void gpiochip_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
if (gc->irq.irq_mask)
gc->irq.irq_mask(d);
gpiochip_disable_irq(gc, hwirq);
}
static void gpiochip_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
gpiochip_enable_irq(gc, hwirq);
if (gc->irq.irq_unmask)
gc->irq.irq_unmask(d);
}
static void gpiochip_irq_enable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
gpiochip_enable_irq(gc, hwirq);
gc->irq.irq_enable(d);
}
static void gpiochip_irq_disable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
unsigned int hwirq = irqd_to_hwirq(d);
gc->irq.irq_disable(d);
gpiochip_disable_irq(gc, hwirq);
}
static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
{
struct irq_chip *irqchip = gc->irq.chip;
if (irqchip->flags & IRQCHIP_IMMUTABLE)
return;
chip_warn(gc, "not an immutable chip, please consider fixing it!\n");
if (!irqchip->irq_request_resources &&
!irqchip->irq_release_resources) {
irqchip->irq_request_resources = gpiochip_irq_reqres;
irqchip->irq_release_resources = gpiochip_irq_relres;
}
if (WARN_ON(gc->irq.irq_enable))
return;
/* Check if the irqchip already has this hook... */
if (irqchip->irq_enable == gpiochip_irq_enable ||
irqchip->irq_mask == gpiochip_irq_mask) {
/*
* ...and if so, give a gentle warning that this is bad
* practice.
*/
chip_info(gc,
"detected irqchip that is shared with multiple gpiochips: please fix the driver.\n");
return;
}
if (irqchip->irq_disable) {
gc->irq.irq_disable = irqchip->irq_disable;
irqchip->irq_disable = gpiochip_irq_disable;
} else {
gc->irq.irq_mask = irqchip->irq_mask;
irqchip->irq_mask = gpiochip_irq_mask;
}
if (irqchip->irq_enable) {
gc->irq.irq_enable = irqchip->irq_enable;
irqchip->irq_enable = gpiochip_irq_enable;
} else {
gc->irq.irq_unmask = irqchip->irq_unmask;
irqchip->irq_unmask = gpiochip_irq_unmask;
}
}
static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc,
struct irq_domain *domain,
bool allocated_externally)
{
if (!domain)
return -EINVAL;
if (gc->to_irq)
chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__);
gc->to_irq = gpiochip_to_irq;
gc->irq.domain = domain;
gc->irq.domain_is_allocated_externally = allocated_externally;
/*
* Using barrier() here to prevent compiler from reordering
* gc->irq.initialized before adding irqdomain.
*/
barrier();
gc->irq.initialized = true;
return 0;
}
/**
* gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip
* @gc: the GPIO chip to add the IRQ chip to
* @lock_key: lockdep class for IRQ lock
* @request_key: lockdep class for IRQ request
*
* Returns:
* 0 on success, or a negative errno on failure.
*/
static int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev);
struct irq_chip *irqchip = gc->irq.chip;
struct irq_domain *domain;
unsigned int type;
unsigned int i;
int ret;
if (!irqchip)
return 0;
if (gc->irq.parent_handler && gc->can_sleep) {
chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n");
return -EINVAL;
}
type = gc->irq.default_type;
/*
* Specifying a default trigger is a terrible idea if DT or ACPI is
* used to configure the interrupts, as you may end up with
* conflicting triggers. Tell the user, and reset to NONE.
*/
if (WARN(fwnode && type != IRQ_TYPE_NONE,
"%pfw: Ignoring %u default trigger\n", fwnode, type))
type = IRQ_TYPE_NONE;
gc->irq.default_type = type;
gc->irq.lock_key = lock_key;
gc->irq.request_key = request_key;
/* If a parent irqdomain is provided, let's build a hierarchy */
if (gpiochip_hierarchy_is_hierarchical(gc)) {
domain = gpiochip_hierarchy_create_domain(gc);
} else {
domain = gpiochip_simple_create_domain(gc);
}
if (IS_ERR(domain))
return PTR_ERR(domain);
if (gc->irq.parent_handler) {
for (i = 0; i < gc->irq.num_parents; i++) {
void *data;
if (gc->irq.per_parent_data)
data = gc->irq.parent_handler_data_array[i];
else
data = gc->irq.parent_handler_data ?: gc;
/*
* The parent IRQ chip is already using the chip_data
* for this IRQ chip, so our callbacks simply use the
* handler_data.
*/
irq_set_chained_handler_and_data(gc->irq.parents[i],
gc->irq.parent_handler,
data);
}
}
gpiochip_set_irq_hooks(gc);
ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false);
if (ret)
return ret;
acpi_gpiochip_request_interrupts(gc);
return 0;
}
/**
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
* @gc: the gpiochip to remove the irqchip from
*
* This is called only from gpiochip_remove()
*/
static void gpiochip_irqchip_remove(struct gpio_chip *gc)
{
struct irq_chip *irqchip = gc->irq.chip;
unsigned int offset;
acpi_gpiochip_free_interrupts(gc);
if (irqchip && gc->irq.parent_handler) {
struct gpio_irq_chip *irq = &gc->irq;
unsigned int i;
for (i = 0; i < irq->num_parents; i++)
irq_set_chained_handler_and_data(irq->parents[i],
NULL, NULL);
}
/* Remove all IRQ mappings and delete the domain */
if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
unsigned int irq;
for (offset = 0; offset < gc->ngpio; offset++) {
if (!gpiochip_irqchip_irq_valid(gc, offset))
continue;
irq = irq_find_mapping(gc->irq.domain, offset);
irq_dispose_mapping(irq);
}
irq_domain_remove(gc->irq.domain);
}
if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) {
if (irqchip->irq_request_resources == gpiochip_irq_reqres) {
irqchip->irq_request_resources = NULL;
irqchip->irq_release_resources = NULL;
}
if (irqchip->irq_enable == gpiochip_irq_enable) {
irqchip->irq_enable = gc->irq.irq_enable;
irqchip->irq_disable = gc->irq.irq_disable;
}
}
gc->irq.irq_enable = NULL;
gc->irq.irq_disable = NULL;
gc->irq.chip = NULL;
gpiochip_irqchip_free_valid_mask(gc);
}
/**
* gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip
* @gc: the gpiochip to add the irqchip to
* @domain: the irqdomain to add to the gpiochip
*
* This function adds an IRQ domain to the gpiochip.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
struct irq_domain *domain)
{
return gpiochip_irqchip_add_allocated_domain(gc, domain, true);
}
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);
#else /* CONFIG_GPIOLIB_IRQCHIP */
static inline int gpiochip_add_irqchip(struct gpio_chip *gc,
struct lock_class_key *lock_key,
struct lock_class_key *request_key)
{
return 0;
}
static void gpiochip_irqchip_remove(struct gpio_chip *gc) {}
static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
{
return 0;
}
static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
{
return 0;
}
static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc)
{ }
#endif /* CONFIG_GPIOLIB_IRQCHIP */
/**
* gpiochip_generic_request() - request the gpio function for a pin
* @gc: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to request for GPIO function
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset)
{
#ifdef CONFIG_PINCTRL
if (list_empty(&gc->gpiodev->pin_ranges))
return 0;
#endif
return pinctrl_gpio_request(gc, offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
/**
* gpiochip_generic_free() - free the gpio function from a pin
* @gc: the gpiochip to request the gpio function for
* @offset: the offset of the GPIO to free from GPIO function
*/
void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset)
{
#ifdef CONFIG_PINCTRL
if (list_empty(&gc->gpiodev->pin_ranges))
return;
#endif
pinctrl_gpio_free(gc, offset);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_free);
/**
* gpiochip_generic_config() - apply configuration for a pin
* @gc: the gpiochip owning the GPIO
* @offset: the offset of the GPIO to apply the configuration
* @config: the configuration to be applied
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset,
unsigned long config)
{
#ifdef CONFIG_PINCTRL
if (list_empty(&gc->gpiodev->pin_ranges))
return -ENOTSUPP;
#endif
return pinctrl_gpio_set_config(gc, offset, config);
}
EXPORT_SYMBOL_GPL(gpiochip_generic_config);
#ifdef CONFIG_PINCTRL
/**
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
* @gc: the gpiochip to add the range for
* @pctldev: the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_group: name of the pin group inside the pin controller
*
* Calling this function directly from a DeviceTree-supported
* pinctrl driver is DEPRECATED. Please see Section 2.1 of
* Documentation/devicetree/bindings/gpio/gpio.txt on how to
* bind pinctrl and gpio drivers via the "gpio-ranges" property.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiochip_add_pingroup_range(struct gpio_chip *gc,
struct pinctrl_dev *pctldev,
unsigned int gpio_offset, const char *pin_group)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = gc->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(gc, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = gc;
pin_range->range.name = gc->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->pctldev = pctldev;
ret = pinctrl_get_group_pins(pctldev, pin_group,
&pin_range->range.pins,
&pin_range->range.npins);
if (ret < 0) {
kfree(pin_range);
return ret;
}
pinctrl_add_gpio_range(pctldev, &pin_range->range);
chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n",
gpio_offset, gpio_offset + pin_range->range.npins - 1,
pinctrl_dev_get_devname(pctldev), pin_group);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
/**
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
* @gc: the gpiochip to add the range for
* @pinctl_name: the dev_name() of the pin controller to map to
* @gpio_offset: the start offset in the current gpio_chip number space
* @pin_offset: the start offset in the pin controller number space
* @npins: the number of pins from the offset of each pin space (GPIO and
* pin controller) to accumulate in this range
*
* Calling this function directly from a DeviceTree-supported
* pinctrl driver is DEPRECATED. Please see Section 2.1 of
* Documentation/devicetree/bindings/gpio/gpio.txt on how to
* bind pinctrl and gpio drivers via the "gpio-ranges" property.
*
* Returns:
* 0 on success, or a negative errno on failure.
*/
int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name,
unsigned int gpio_offset, unsigned int pin_offset,
unsigned int npins)
{
struct gpio_pin_range *pin_range;
struct gpio_device *gdev = gc->gpiodev;
int ret;
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
if (!pin_range) {
chip_err(gc, "failed to allocate pin ranges\n");
return -ENOMEM;
}
/* Use local offset as range ID */
pin_range->range.id = gpio_offset;
pin_range->range.gc = gc;
pin_range->range.name = gc->label;
pin_range->range.base = gdev->base + gpio_offset;
pin_range->range.pin_base = pin_offset;
pin_range->range.npins = npins;
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
&pin_range->range);
if (IS_ERR(pin_range->pctldev)) {
ret = PTR_ERR(pin_range->pctldev);
chip_err(gc, "could not create pin range\n");
kfree(pin_range);
return ret;
}
chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
gpio_offset, gpio_offset + npins - 1,
pinctl_name,
pin_offset, pin_offset + npins - 1);
list_add_tail(&pin_range->node, &gdev->pin_ranges);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
/**
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
* @gc: the chip to remove all the mappings for
*/
void gpiochip_remove_pin_ranges(struct gpio_chip *gc)
{
struct gpio_pin_range *pin_range, *tmp;
struct gpio_device *gdev = gc->gpiodev;
list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) {
list_del(&pin_range->node);
pinctrl_remove_gpio_range(pin_range->pctldev,
&pin_range->range);
kfree(pin_range);
}
}
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
#endif /* CONFIG_PINCTRL */
/* These "optional" allocation calls help prevent drivers from stomping
* on each other, and help provide better diagnostics in debugfs.
* They're called even less than the "set direction" calls.
*/
static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
{
unsigned int offset;
int ret;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
return -EBUSY;
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
if (guard.gc->request) {
offset = gpio_chip_hwgpio(desc);
if (gpiochip_line_is_valid(guard.gc, offset))
ret = guard.gc->request(guard.gc, offset);
else
ret = -EINVAL;
if (ret)
goto out_clear_bit;
}
if (guard.gc->get_direction)
gpiod_get_direction(desc);
ret = desc_set_label(desc, label ? : "?");
if (ret)
goto out_clear_bit;
return 0;
out_clear_bit:
clear_bit(FLAG_REQUESTED, &desc->flags);
return ret;
}
/*
* This descriptor validation needs to be inserted verbatim into each
* function taking a descriptor, so we need to use a preprocessor
* macro to avoid endless duplication. If the desc is NULL it is an
* optional GPIO and calls should just bail out.
*/
static int validate_desc(const struct gpio_desc *desc, const char *func)
{
if (!desc)
return 0;
if (IS_ERR(desc)) {
pr_warn("%s: invalid GPIO (errorpointer)\n", func);
return PTR_ERR(desc);
}
return 1;
}
#define VALIDATE_DESC(desc) do { \
int __valid = validate_desc(desc, __func__); \
if (__valid <= 0) \
return __valid; \
} while (0)
#define VALIDATE_DESC_VOID(desc) do { \
int __valid = validate_desc(desc, __func__); \
if (__valid <= 0) \
return; \
} while (0)
int gpiod_request(struct gpio_desc *desc, const char *label)
{
int ret = -EPROBE_DEFER;
VALIDATE_DESC(desc);
if (try_module_get(desc->gdev->owner)) {
ret = gpiod_request_commit(desc, label);
if (ret)
module_put(desc->gdev->owner);
else
gpio_device_get(desc->gdev);
}
if (ret)
gpiod_dbg(desc, "%s: status %d\n", __func__, ret);
return ret;
}
static void gpiod_free_commit(struct gpio_desc *desc)
{
unsigned long flags;
might_sleep();
CLASS(gpio_chip_guard, guard)(desc);
flags = READ_ONCE(desc->flags);
if (guard.gc && test_bit(FLAG_REQUESTED, &flags)) {
if (guard.gc->free)
guard.gc->free(guard.gc, gpio_chip_hwgpio(desc));
clear_bit(FLAG_ACTIVE_LOW, &flags);
clear_bit(FLAG_REQUESTED, &flags);
clear_bit(FLAG_OPEN_DRAIN, &flags);
clear_bit(FLAG_OPEN_SOURCE, &flags);
clear_bit(FLAG_PULL_UP, &flags);
clear_bit(FLAG_PULL_DOWN, &flags);
clear_bit(FLAG_BIAS_DISABLE, &flags);
clear_bit(FLAG_EDGE_RISING, &flags);
clear_bit(FLAG_EDGE_FALLING, &flags);
clear_bit(FLAG_IS_HOGGED, &flags);
#ifdef CONFIG_OF_DYNAMIC
WRITE_ONCE(desc->hog, NULL);
#endif
desc_set_label(desc, NULL);
WRITE_ONCE(desc->flags, flags);
gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED);
}
}
void gpiod_free(struct gpio_desc *desc)
{
VALIDATE_DESC_VOID(desc);
gpiod_free_commit(desc);
module_put(desc->gdev->owner);
gpio_device_put(desc->gdev);
}
/**
* gpiochip_dup_line_label - Get a copy of the consumer label.
* @gc: GPIO chip controlling this line.
* @offset: Hardware offset of the line.
*
* Returns:
* Pointer to a copy of the consumer label if the line is requested or NULL
* if it's not. If a valid pointer was returned, it must be freed using
* kfree(). In case of a memory allocation error, the function returns %ENOMEM.
*
* Must not be called from atomic context.
*/
char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc;
char *label;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return NULL;
if (!test_bit(FLAG_REQUESTED, &desc->flags))
return NULL;
guard(srcu)(&desc->gdev->desc_srcu);
label = kstrdup(gpiod_get_label(desc), GFP_KERNEL);
if (!label)
return ERR_PTR(-ENOMEM);
return label;
}
EXPORT_SYMBOL_GPL(gpiochip_dup_line_label);
static inline const char *function_name_or_default(const char *con_id)
{
return con_id ?: "(default)";
}
/**
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
* @gc: GPIO chip
* @hwnum: hardware number of the GPIO for which to request the descriptor
* @label: label for the GPIO
* @lflags: lookup flags for this GPIO or 0 if default, this can be used to
* specify things like line inversion semantics with the machine flags
* such as GPIO_OUT_LOW
* @dflags: descriptor request flags for this GPIO or 0 if default, this
* can be used to specify consumer semantics such as open drain
*
* Function allows GPIO chip drivers to request and use their own GPIO
* descriptors via gpiolib API. Difference to gpiod_request() is that this
* function will not increase reference count of the GPIO chip module. This
* allows the GPIO chip module to be unloaded as needed (we assume that the
* GPIO chip driver handles freeing the GPIOs it has requested).
*
* Returns:
* A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error
* code on failure.
*/
struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc,
unsigned int hwnum,
const char *label,
enum gpio_lookup_flags lflags,
enum gpiod_flags dflags)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum);
const char *name = function_name_or_default(label);
int ret;
if (IS_ERR(desc)) {
chip_err(gc, "failed to get GPIO %s descriptor\n", name);
return desc;
}
ret = gpiod_request_commit(desc, label);
if (ret < 0)
return ERR_PTR(ret);
ret = gpiod_configure_flags(desc, label, lflags, dflags);
if (ret) {
gpiod_free_commit(desc);
chip_err(gc, "setup of own GPIO %s failed\n", name);
return ERR_PTR(ret);
}
return desc;
}
EXPORT_SYMBOL_GPL(gpiochip_request_own_desc);
/**
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
* @desc: GPIO descriptor to free
*
* Function frees the given GPIO requested previously with
* gpiochip_request_own_desc().
*/
void gpiochip_free_own_desc(struct gpio_desc *desc)
{
if (desc)
gpiod_free_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
/*
* Drivers MUST set GPIO direction before making get/set calls. In
* some cases this is done in early boot, before IRQs are enabled.
*
* As a rule these aren't called more than once (except for drivers
* using the open-drain emulation idiom) so these are natural places
* to accumulate extra debugging checks. Note that we can't (yet)
* rely on gpio_request() having been called beforehand.
*/
static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset,
unsigned long config)
{
if (!gc->set_config)
return -ENOTSUPP;
return gc->set_config(gc, offset, config);
}
static int gpio_set_config_with_argument(struct gpio_desc *desc,
enum pin_config_param mode,
u32 argument)
{
unsigned long config;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
config = pinconf_to_config_packed(mode, argument);
return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
}
static int gpio_set_config_with_argument_optional(struct gpio_desc *desc,
enum pin_config_param mode,
u32 argument)
{
struct device *dev = &desc->gdev->dev;
int gpio = gpio_chip_hwgpio(desc);
int ret;
ret = gpio_set_config_with_argument(desc, mode, argument);
if (ret != -ENOTSUPP)
return ret;
switch (mode) {
case PIN_CONFIG_PERSIST_STATE:
dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio);
break;
default:
break;
}
return 0;
}
static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode)
{
return gpio_set_config_with_argument(desc, mode, 0);
}
static int gpio_set_bias(struct gpio_desc *desc)
{
enum pin_config_param bias;
unsigned long flags;
unsigned int arg;
flags = READ_ONCE(desc->flags);
if (test_bit(FLAG_BIAS_DISABLE, &flags))
bias = PIN_CONFIG_BIAS_DISABLE;
else if (test_bit(FLAG_PULL_UP, &flags))
bias = PIN_CONFIG_BIAS_PULL_UP;
else if (test_bit(FLAG_PULL_DOWN, &flags))
bias = PIN_CONFIG_BIAS_PULL_DOWN;
else
return 0;
switch (bias) {
case PIN_CONFIG_BIAS_PULL_DOWN:
case PIN_CONFIG_BIAS_PULL_UP:
arg = 1;
break;
default:
arg = 0;
break;
}
return gpio_set_config_with_argument_optional(desc, bias, arg);
}
/**
* gpio_set_debounce_timeout() - Set debounce timeout
* @desc: GPIO descriptor to set the debounce timeout
* @debounce: Debounce timeout in microseconds
*
* The function calls the certain GPIO driver to set debounce timeout
* in the hardware.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce)
{
return gpio_set_config_with_argument_optional(desc,
PIN_CONFIG_INPUT_DEBOUNCE,
debounce);
}
/**
* gpiod_direction_input - set the GPIO direction to input
* @desc: GPIO to set to input
*
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
* be called safely on it.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_direction_input(struct gpio_desc *desc)
{
int ret = 0;
VALIDATE_DESC(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
/*
* It is legal to have no .get() and .direction_input() specified if
* the chip is output-only, but you can't specify .direction_input()
* and not support the .get() operation, that doesn't make sense.
*/
if (!guard.gc->get && guard.gc->direction_input) {
gpiod_warn(desc,
"%s: missing get() but have direction_input()\n",
__func__);
return -EIO;
}
/*
* If we have a .direction_input() callback, things are simple,
* just call it. Else we are some input-only chip so try to check the
* direction (if .get_direction() is supported) else we silently
* assume we are in input mode after this.
*/
if (guard.gc->direction_input) {
ret = guard.gc->direction_input(guard.gc,
gpio_chip_hwgpio(desc));
} else if (guard.gc->get_direction &&
(guard.gc->get_direction(guard.gc,
gpio_chip_hwgpio(desc)) != 1)) {
gpiod_warn(desc,
"%s: missing direction_input() operation and line is output\n",
__func__);
return -EIO;
}
if (ret == 0) {
clear_bit(FLAG_IS_OUT, &desc->flags);
ret = gpio_set_bias(desc);
}
trace_gpio_direction(desc_to_gpio(desc), 1, ret);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_direction_input);
static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value)
{
int val = !!value, ret = 0;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
/*
* It's OK not to specify .direction_output() if the gpiochip is
* output-only, but if there is then not even a .set() operation it
* is pretty tricky to drive the output line.
*/
if (!guard.gc->set && !guard.gc->direction_output) {
gpiod_warn(desc,
"%s: missing set() and direction_output() operations\n",
__func__);
return -EIO;
}
if (guard.gc->direction_output) {
ret = guard.gc->direction_output(guard.gc,
gpio_chip_hwgpio(desc), val);
} else {
/* Check that we are in output mode if we can */
if (guard.gc->get_direction &&
guard.gc->get_direction(guard.gc, gpio_chip_hwgpio(desc))) {
gpiod_warn(desc,
"%s: missing direction_output() operation\n",
__func__);
return -EIO;
}
/*
* If we can't actively set the direction, we are some
* output-only chip, so just drive the output as desired.
*/
guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), val);
}
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
trace_gpio_value(desc_to_gpio(desc), 0, val);
trace_gpio_direction(desc_to_gpio(desc), 0, ret);
return ret;
}
/**
* gpiod_direction_output_raw - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as raw value on the physical line without regard for the ACTIVE_LOW status.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
{
VALIDATE_DESC(desc);
return gpiod_direction_output_raw_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
/**
* gpiod_direction_output - set the GPIO direction to output
* @desc: GPIO to set to output
* @value: initial output value of the GPIO
*
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
* be called safely on it. The initial value of the output must be specified
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_direction_output(struct gpio_desc *desc, int value)
{
unsigned long flags;
int ret;
VALIDATE_DESC(desc);
flags = READ_ONCE(desc->flags);
if (test_bit(FLAG_ACTIVE_LOW, &flags))
value = !value;
else
value = !!value;
/* GPIOs used for enabled IRQs shall not be set as output */
if (test_bit(FLAG_USED_AS_IRQ, &flags) &&
test_bit(FLAG_IRQ_IS_ENABLED, &flags)) {
gpiod_err(desc,
"%s: tried to set a GPIO tied to an IRQ as output\n",
__func__);
return -EIO;
}
if (test_bit(FLAG_OPEN_DRAIN, &flags)) {
/* First see if we can enable open drain in hardware */
ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN);
if (!ret)
goto set_output_value;
/* Emulate open drain by not actively driving the line high */
if (value) {
ret = gpiod_direction_input(desc);
goto set_output_flag;
}
} else if (test_bit(FLAG_OPEN_SOURCE, &flags)) {
ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE);
if (!ret)
goto set_output_value;
/* Emulate open source by not actively driving the line low */
if (!value) {
ret = gpiod_direction_input(desc);
goto set_output_flag;
}
} else {
gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL);
}
set_output_value:
ret = gpio_set_bias(desc);
if (ret)
return ret;
return gpiod_direction_output_raw_commit(desc, value);
set_output_flag:
/*
* When emulating open-source or open-drain functionalities by not
* actively driving the line (setting mode to input) we still need to
* set the IS_OUT flag or otherwise we won't be able to set the line
* value anymore.
*/
if (ret == 0)
set_bit(FLAG_IS_OUT, &desc->flags);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_direction_output);
/**
* gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds.
*
* @desc: GPIO to enable.
* @flags: Flags related to GPIO edge.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
{
int ret = 0;
VALIDATE_DESC(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
if (!guard.gc->en_hw_timestamp) {
gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
return -ENOTSUPP;
}
ret = guard.gc->en_hw_timestamp(guard.gc,
gpio_chip_hwgpio(desc), flags);
if (ret)
gpiod_warn(desc, "%s: hw ts request failed\n", __func__);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns);
/**
* gpiod_disable_hw_timestamp_ns - Disable hardware timestamp.
*
* @desc: GPIO to disable.
* @flags: Flags related to GPIO edge, same value as used during enable call.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags)
{
int ret = 0;
VALIDATE_DESC(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
if (!guard.gc->dis_hw_timestamp) {
gpiod_warn(desc, "%s: hw ts not supported\n", __func__);
return -ENOTSUPP;
}
ret = guard.gc->dis_hw_timestamp(guard.gc, gpio_chip_hwgpio(desc),
flags);
if (ret)
gpiod_warn(desc, "%s: hw ts release failed\n", __func__);
return ret;
}
EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns);
/**
* gpiod_set_config - sets @config for a GPIO
* @desc: descriptor of the GPIO for which to set the configuration
* @config: Same packed config format as generic pinconf
*
* Returns:
* 0 on success, %-ENOTSUPP if the controller doesn't support setting the
* configuration.
*/
int gpiod_set_config(struct gpio_desc *desc, unsigned long config)
{
VALIDATE_DESC(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
return gpio_do_set_config(guard.gc, gpio_chip_hwgpio(desc), config);
}
EXPORT_SYMBOL_GPL(gpiod_set_config);
/**
* gpiod_set_debounce - sets @debounce time for a GPIO
* @desc: descriptor of the GPIO for which to set debounce time
* @debounce: debounce time in microseconds
*
* Returns:
* 0 on success, %-ENOTSUPP if the controller doesn't support setting the
* debounce time.
*/
int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce)
{
unsigned long config;
config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
return gpiod_set_config(desc, config);
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
/**
* gpiod_set_transitory - Lose or retain GPIO state on suspend or reset
* @desc: descriptor of the GPIO for which to configure persistence
* @transitory: True to lose state on suspend or reset, false for persistence
*
* Returns:
* 0 on success, otherwise a negative error code.
*/
int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
{
VALIDATE_DESC(desc);
/*
* Handle FLAG_TRANSITORY first, enabling queries to gpiolib for
* persistence state.
*/
assign_bit(FLAG_TRANSITORY, &desc->flags, transitory);
/* If the driver supports it, set the persistence state now */
return gpio_set_config_with_argument_optional(desc,
PIN_CONFIG_PERSIST_STATE,
!transitory);
}
/**
* gpiod_is_active_low - test whether a GPIO is active-low or not
* @desc: the gpio descriptor to test
*
* Returns:
* 1 if the GPIO is active-low, 0 otherwise.
*/
int gpiod_is_active_low(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
/**
* gpiod_toggle_active_low - toggle whether a GPIO is active-low or not
* @desc: the gpio descriptor to change
*/
void gpiod_toggle_active_low(struct gpio_desc *desc)
{
VALIDATE_DESC_VOID(desc);
change_bit(FLAG_ACTIVE_LOW, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiod_toggle_active_low);
static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc)
{
return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO;
}
/* I/O calls are only valid after configuration completed; the relevant
* "is this a valid GPIO" error checks should already have been done.
*
* "Get" operations are often inlinable as reading a pin value register,
* and masking the relevant bit in that register.
*
* When "set" operations are inlinable, they involve writing that mask to
* one register to set a low value, or a different register to set it high.
* Otherwise locking is needed, so there may be little value to inlining.
*
*------------------------------------------------------------------------
*
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
* have requested the GPIO. That can include implicit requesting by
* a direction setting call. Marking a gpio as requested locks its chip
* in memory, guaranteeing that these table lookups need no more locking
* and that gpiochip_remove() will fail.
*
* REVISIT when debugging, consider adding some instrumentation to ensure
* that the GPIO was actually requested.
*/
static int gpiod_get_raw_value_commit(const struct gpio_desc *desc)
{
struct gpio_device *gdev;
struct gpio_chip *gc;
int value;
/* FIXME Unable to use gpio_chip_guard due to const desc. */
gdev = desc->gdev;
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (!gc)
return -ENODEV;
value = gpio_chip_get_value(gc, desc);
value = value < 0 ? value : !!value;
trace_gpio_value(desc_to_gpio(desc), 1, value);
return value;
}
static int gpio_chip_get_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
if (gc->get_multiple)
return gc->get_multiple(gc, mask, bits);
if (gc->get) {
int i, value;
for_each_set_bit(i, mask, gc->ngpio) {
value = gc->get(gc, i);
if (value < 0)
return value;
__assign_bit(i, bits, value);
}
return 0;
}
return -EIO;
}
/* The 'other' chip must be protected with its GPIO device's SRCU. */
static bool gpio_device_chip_cmp(struct gpio_device *gdev, struct gpio_chip *gc)
{
guard(srcu)(&gdev->srcu);
return gc == srcu_dereference(gdev->chip, &gdev->srcu);
}
int gpiod_get_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
int ret, i = 0;
/*
* Validate array_info against desc_array and its size.
* It should immediately follow desc_array if both
* have been obtained from the same gpiod_get_array() call.
*/
if (array_info && array_info->desc == desc_array &&
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
WARN_ON(array_info->chip->can_sleep);
ret = gpio_chip_get_multiple(array_info->chip,
array_info->get_mask,
value_bitmap);
if (ret)
return ret;
if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
bitmap_xor(value_bitmap, value_bitmap,
array_info->invert_mask, array_size);
i = find_first_zero_bit(array_info->get_mask, array_size);
if (i == array_size)
return 0;
} else {
array_info = NULL;
}
while (i < array_size) {
DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
unsigned long *mask, *bits;
int first, j;
CLASS(gpio_chip_guard, guard)(desc_array[i]);
if (!guard.gc)
return -ENODEV;
if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath_mask;
bits = fastpath_bits;
} else {
gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
mask = bitmap_alloc(guard.gc->ngpio, flags);
if (!mask)
return -ENOMEM;
bits = bitmap_alloc(guard.gc->ngpio, flags);
if (!bits) {
bitmap_free(mask);
return -ENOMEM;
}
}
bitmap_zero(mask, guard.gc->ngpio);
if (!can_sleep)
WARN_ON(guard.gc->can_sleep);
/* collect all inputs belonging to the same chip */
first = i;
do {
const struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
__set_bit(hwgpio, mask);
i++;
if (array_info)
i = find_next_zero_bit(array_info->get_mask,
array_size, i);
} while ((i < array_size) &&
gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
ret = gpio_chip_get_multiple(guard.gc, mask, bits);
if (ret) {
if (mask != fastpath_mask)
bitmap_free(mask);
if (bits != fastpath_bits)
bitmap_free(bits);
return ret;
}
for (j = first; j < i; ) {
const struct gpio_desc *desc = desc_array[j];
int hwgpio = gpio_chip_hwgpio(desc);
int value = test_bit(hwgpio, bits);
if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
__assign_bit(j, value_bitmap, value);
trace_gpio_value(desc_to_gpio(desc), 1, value);
j++;
if (array_info)
j = find_next_zero_bit(array_info->get_mask, i,
j);
}
if (mask != fastpath_mask)
bitmap_free(mask);
if (bits != fastpath_bits)
bitmap_free(bits);
}
return 0;
}
/**
* gpiod_get_raw_value() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Returns:
* The GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_raw_value(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
/* Should be using gpiod_get_raw_value_cansleep() */
WARN_ON(desc->gdev->can_sleep);
return gpiod_get_raw_value_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
/**
* gpiod_get_value() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Returns:
* The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
int gpiod_get_value(const struct gpio_desc *desc)
{
int value;
VALIDATE_DESC(desc);
/* Should be using gpiod_get_value_cansleep() */
WARN_ON(desc->gdev->can_sleep);
value = gpiod_get_raw_value_commit(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value);
/**
* gpiod_get_raw_array_value() - read raw values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function can be called from contexts where we cannot sleep,
* and it will complain if the GPIO chip functions potentially sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_get_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(true, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value);
/**
* gpiod_get_array_value() - read values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function can be called from contexts where we cannot sleep,
* and it will complain if the GPIO chip functions potentially sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_get_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(false, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_array_value);
/*
* gpio_set_open_drain_value_commit() - Set the open drain gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0, offset = gpio_chip_hwgpio(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return;
if (value) {
ret = guard.gc->direction_input(guard.gc, offset);
} else {
ret = guard.gc->direction_output(guard.gc, offset, 0);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
}
trace_gpio_direction(desc_to_gpio(desc), value, ret);
if (ret < 0)
gpiod_err(desc,
"%s: Error in set_value for open drain err %d\n",
__func__, ret);
}
/*
* _gpio_set_open_source_value() - Set the open source gpio's value.
* @desc: gpio descriptor whose state need to be set.
* @value: Non-zero for setting it HIGH otherwise it will set to LOW.
*/
static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value)
{
int ret = 0, offset = gpio_chip_hwgpio(desc);
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return;
if (value) {
ret = guard.gc->direction_output(guard.gc, offset, 1);
if (!ret)
set_bit(FLAG_IS_OUT, &desc->flags);
} else {
ret = guard.gc->direction_input(guard.gc, offset);
}
trace_gpio_direction(desc_to_gpio(desc), !value, ret);
if (ret < 0)
gpiod_err(desc,
"%s: Error in set_value for open source err %d\n",
__func__, ret);
}
static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value)
{
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return;
trace_gpio_value(desc_to_gpio(desc), 0, value);
guard.gc->set(guard.gc, gpio_chip_hwgpio(desc), value);
}
/*
* set multiple outputs on the same chip;
* use the chip's set_multiple function if available;
* otherwise set the outputs sequentially;
* @chip: the GPIO chip we operate on
* @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word
* defines which outputs are to be changed
* @bits: bit value array; one bit per output; BITS_PER_LONG bits per word
* defines the values the outputs specified by mask are to be set to
*/
static void gpio_chip_set_multiple(struct gpio_chip *gc,
unsigned long *mask, unsigned long *bits)
{
if (gc->set_multiple) {
gc->set_multiple(gc, mask, bits);
} else {
unsigned int i;
/* set outputs if the corresponding mask bit is set */
for_each_set_bit(i, mask, gc->ngpio)
gc->set(gc, i, test_bit(i, bits));
}
}
int gpiod_set_array_value_complex(bool raw, bool can_sleep,
unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
int i = 0;
/*
* Validate array_info against desc_array and its size.
* It should immediately follow desc_array if both
* have been obtained from the same gpiod_get_array() call.
*/
if (array_info && array_info->desc == desc_array &&
array_size <= array_info->size &&
(void *)array_info == desc_array + array_info->size) {
if (!can_sleep)
WARN_ON(array_info->chip->can_sleep);
if (!raw && !bitmap_empty(array_info->invert_mask, array_size))
bitmap_xor(value_bitmap, value_bitmap,
array_info->invert_mask, array_size);
gpio_chip_set_multiple(array_info->chip, array_info->set_mask,
value_bitmap);
i = find_first_zero_bit(array_info->set_mask, array_size);
if (i == array_size)
return 0;
} else {
array_info = NULL;
}
while (i < array_size) {
DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO);
DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO);
unsigned long *mask, *bits;
int count = 0;
CLASS(gpio_chip_guard, guard)(desc_array[i]);
if (!guard.gc)
return -ENODEV;
if (likely(guard.gc->ngpio <= FASTPATH_NGPIO)) {
mask = fastpath_mask;
bits = fastpath_bits;
} else {
gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC;
mask = bitmap_alloc(guard.gc->ngpio, flags);
if (!mask)
return -ENOMEM;
bits = bitmap_alloc(guard.gc->ngpio, flags);
if (!bits) {
bitmap_free(mask);
return -ENOMEM;
}
}
bitmap_zero(mask, guard.gc->ngpio);
if (!can_sleep)
WARN_ON(guard.gc->can_sleep);
do {
struct gpio_desc *desc = desc_array[i];
int hwgpio = gpio_chip_hwgpio(desc);
int value = test_bit(i, value_bitmap);
/*
* Pins applicable for fast input but not for
* fast output processing may have been already
* inverted inside the fast path, skip them.
*/
if (!raw && !(array_info &&
test_bit(i, array_info->invert_mask)) &&
test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
trace_gpio_value(desc_to_gpio(desc), 0, value);
/*
* collect all normal outputs belonging to the same chip
* open drain and open source outputs are set individually
*/
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) {
gpio_set_open_drain_value_commit(desc, value);
} else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) {
gpio_set_open_source_value_commit(desc, value);
} else {
__set_bit(hwgpio, mask);
__assign_bit(hwgpio, bits, value);
count++;
}
i++;
if (array_info)
i = find_next_zero_bit(array_info->set_mask,
array_size, i);
} while ((i < array_size) &&
gpio_device_chip_cmp(desc_array[i]->gdev, guard.gc));
/* push collected bits to outputs */
if (count != 0)
gpio_chip_set_multiple(guard.gc, mask, bits);
if (mask != fastpath_mask)
bitmap_free(mask);
if (bits != fastpath_bits)
bitmap_free(bits);
}
return 0;
}
/**
* gpiod_set_raw_value() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_raw_value_cansleep() */
WARN_ON(desc->gdev->can_sleep);
gpiod_set_raw_value_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
/**
* gpiod_set_value_nocheck() - set a GPIO line value without checking
* @desc: the descriptor to set the value on
* @value: value to set
*
* This sets the value of a GPIO line backing a descriptor, applying
* different semantic quirks like active low and open drain/source
* handling.
*/
static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value)
{
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
gpio_set_open_drain_value_commit(desc, value);
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
gpio_set_open_source_value_commit(desc, value);
else
gpiod_set_raw_value_commit(desc, value);
}
/**
* gpiod_set_value() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW,
* OPEN_DRAIN and OPEN_SOURCE flags into account.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*/
void gpiod_set_value(struct gpio_desc *desc, int value)
{
VALIDATE_DESC_VOID(desc);
/* Should be using gpiod_set_value_cansleep() */
WARN_ON(desc->gdev->can_sleep);
gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value);
/**
* gpiod_set_raw_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_set_raw_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(true, false, array_size,
desc_array, array_info, value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value);
/**
* gpiod_set_array_value() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function can be called from contexts where we cannot sleep, and will
* complain if the GPIO chip functions potentially sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_set_array_value(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(false, false, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value);
/**
* gpiod_cansleep() - report whether gpio value access may sleep
* @desc: gpio to check
*
* Returns:
* 0 for non-sleepable, 1 for sleepable, or an error code in case of error.
*/
int gpiod_cansleep(const struct gpio_desc *desc)
{
VALIDATE_DESC(desc);
return desc->gdev->can_sleep;
}
EXPORT_SYMBOL_GPL(gpiod_cansleep);
/**
* gpiod_set_consumer_name() - set the consumer name for the descriptor
* @desc: gpio to set the consumer name on
* @name: the new consumer name
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name)
{
VALIDATE_DESC(desc);
return desc_set_label(desc, name);
}
EXPORT_SYMBOL_GPL(gpiod_set_consumer_name);
/**
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
* @desc: gpio whose IRQ will be returned (already requested)
*
* Returns:
* The IRQ corresponding to the passed GPIO, or an error code in case of error.
*/
int gpiod_to_irq(const struct gpio_desc *desc)
{
struct gpio_device *gdev;
struct gpio_chip *gc;
int offset;
/*
* Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics
* requires this function to not return zero on an invalid descriptor
* but rather a negative error number.
*/
if (IS_ERR_OR_NULL(desc))
return -EINVAL;
gdev = desc->gdev;
/* FIXME Cannot use gpio_chip_guard due to const desc. */
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (!gc)
return -ENODEV;
offset = gpio_chip_hwgpio(desc);
if (gc->to_irq) {
int retirq = gc->to_irq(gc, offset);
/* Zero means NO_IRQ */
if (!retirq)
return -ENXIO;
return retirq;
}
#ifdef CONFIG_GPIOLIB_IRQCHIP
if (gc->irq.chip) {
/*
* Avoid race condition with other code, which tries to lookup
* an IRQ before the irqchip has been properly registered,
* i.e. while gpiochip is still being brought up.
*/
return -EPROBE_DEFER;
}
#endif
return -ENXIO;
}
EXPORT_SYMBOL_GPL(gpiod_to_irq);
/**
* gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ
* @gc: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to lock down
* a certain GPIO line to be used for IRQs.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return PTR_ERR(desc);
/*
* If it's fast: flush the direction setting if something changed
* behind our back
*/
if (!gc->can_sleep && gc->get_direction) {
int dir = gpiod_get_direction(desc);
if (dir < 0) {
chip_err(gc, "%s: cannot get GPIO direction\n",
__func__);
return dir;
}
}
/* To be valid for IRQ the line needs to be input or open drain */
if (test_bit(FLAG_IS_OUT, &desc->flags) &&
!test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
chip_err(gc,
"%s: tried to flag a GPIO set as output for IRQ\n",
__func__);
return -EIO;
}
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq);
/**
* gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ
* @gc: the chip the GPIO to lock belongs to
* @offset: the offset of the GPIO to lock as IRQ
*
* This is used directly by GPIO drivers that want to indicate
* that a certain GPIO is no longer used exclusively for IRQ.
*/
void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc;
desc = gpiochip_get_desc(gc, offset);
if (IS_ERR(desc))
return;
clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq);
void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
if (!IS_ERR(desc) &&
!WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags)))
clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
}
EXPORT_SYMBOL_GPL(gpiochip_disable_irq);
void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset)
{
struct gpio_desc *desc = gpiochip_get_desc(gc, offset);
if (!IS_ERR(desc) &&
!WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) {
/*
* We must not be output when using IRQ UNLESS we are
* open drain.
*/
WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) &&
!test_bit(FLAG_OPEN_DRAIN, &desc->flags));
set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags);
}
}
EXPORT_SYMBOL_GPL(gpiochip_enable_irq);
bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_irq);
int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset)
{
int ret;
if (!try_module_get(gc->gpiodev->owner))
return -ENODEV;
ret = gpiochip_lock_as_irq(gc, offset);
if (ret) {
chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset);
module_put(gc->gpiodev->owner);
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_reqres_irq);
void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset)
{
gpiochip_unlock_as_irq(gc, offset);
module_put(gc->gpiodev->owner);
}
EXPORT_SYMBOL_GPL(gpiochip_relres_irq);
bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain);
bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source);
bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset)
{
if (offset >= gc->ngpio)
return false;
return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags);
}
EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent);
/**
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
* @desc: gpio whose value will be returned
*
* Returns:
* The GPIO's raw value, i.e. the value of the physical line disregarding
* its ACTIVE_LOW status, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
{
might_sleep();
VALIDATE_DESC(desc);
return gpiod_get_raw_value_commit(desc);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
/**
* gpiod_get_value_cansleep() - return a gpio's value
* @desc: gpio whose value will be returned
*
* Returns:
* The GPIO's logical value, i.e. taking the ACTIVE_LOW status into
* account, or negative errno on failure.
*
* This function is to be called from contexts that can sleep.
*/
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
{
int value;
might_sleep();
VALIDATE_DESC(desc);
value = gpiod_get_raw_value_commit(desc);
if (value < 0)
return value;
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
value = !value;
return value;
}
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
/**
* gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep();
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(true, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep);
/**
* gpiod_get_array_value_cansleep() - read values from an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be read
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap to store the read values
*
* Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function is to be called from contexts that can sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_get_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep();
if (!desc_array)
return -EINVAL;
return gpiod_get_array_value_complex(false, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep);
/**
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the raw value of the GPIO, i.e. the value of its physical line without
* regard for its ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep();
VALIDATE_DESC_VOID(desc);
gpiod_set_raw_value_commit(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
/**
* gpiod_set_value_cansleep() - assign a gpio's value
* @desc: gpio whose value will be assigned
* @value: value to assign
*
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
* account
*
* This function is to be called from contexts that can sleep.
*/
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
{
might_sleep();
VALIDATE_DESC_VOID(desc);
gpiod_set_value_nocheck(desc, value);
}
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
/**
* gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the raw values of the GPIOs, i.e. the values of the physical lines
* without regard for their ACTIVE_LOW status.
*
* This function is to be called from contexts that can sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep();
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(true, true, array_size, desc_array,
array_info, value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep);
/**
* gpiod_add_lookup_tables() - register GPIO device consumers
* @tables: list of tables of consumers to register
* @n: number of tables in the list
*/
void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n)
{
unsigned int i;
mutex_lock(&gpio_lookup_lock);
for (i = 0; i < n; i++)
list_add_tail(&tables[i]->list, &gpio_lookup_list);
mutex_unlock(&gpio_lookup_lock);
}
/**
* gpiod_set_array_value_cansleep() - assign values to an array of GPIOs
* @array_size: number of elements in the descriptor array / value bitmap
* @desc_array: array of GPIO descriptors whose values will be assigned
* @array_info: information on applicability of fast bitmap processing path
* @value_bitmap: bitmap of values to assign
*
* Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status
* into account.
*
* This function is to be called from contexts that can sleep.
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_set_array_value_cansleep(unsigned int array_size,
struct gpio_desc **desc_array,
struct gpio_array *array_info,
unsigned long *value_bitmap)
{
might_sleep();
if (!desc_array)
return -EINVAL;
return gpiod_set_array_value_complex(false, true, array_size,
desc_array, array_info,
value_bitmap);
}
EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep);
void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action)
{
blocking_notifier_call_chain(&desc->gdev->line_state_notifier,
action, desc);
}
/**
* gpiod_add_lookup_table() - register GPIO device consumers
* @table: table of consumers to register
*/
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
{
gpiod_add_lookup_tables(&table, 1);
}
EXPORT_SYMBOL_GPL(gpiod_add_lookup_table);
/**
* gpiod_remove_lookup_table() - unregister GPIO device consumers
* @table: table of consumers to unregister
*/
void gpiod_remove_lookup_table(struct gpiod_lookup_table *table)
{
/* Nothing to remove */
if (!table)
return;
mutex_lock(&gpio_lookup_lock);
list_del(&table->list);
mutex_unlock(&gpio_lookup_lock);
}
EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table);
/**
* gpiod_add_hogs() - register a set of GPIO hogs from machine code
* @hogs: table of gpio hog entries with a zeroed sentinel at the end
*/
void gpiod_add_hogs(struct gpiod_hog *hogs)
{
struct gpiod_hog *hog;
mutex_lock(&gpio_machine_hogs_mutex);
for (hog = &hogs[0]; hog->chip_label; hog++) {
list_add_tail(&hog->list, &gpio_machine_hogs);
/*
* The chip may have been registered earlier, so check if it
* exists and, if so, try to hog the line now.
*/
struct gpio_device *gdev __free(gpio_device_put) =
gpio_device_find_by_label(hog->chip_label);
if (gdev)
gpiochip_machine_hog(gpio_device_get_chip(gdev), hog);
}
mutex_unlock(&gpio_machine_hogs_mutex);
}
EXPORT_SYMBOL_GPL(gpiod_add_hogs);
void gpiod_remove_hogs(struct gpiod_hog *hogs)
{
struct gpiod_hog *hog;
mutex_lock(&gpio_machine_hogs_mutex);
for (hog = &hogs[0]; hog->chip_label; hog++)
list_del(&hog->list);
mutex_unlock(&gpio_machine_hogs_mutex);
}
EXPORT_SYMBOL_GPL(gpiod_remove_hogs);
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
struct gpiod_lookup_table *table;
list_for_each_entry(table, &gpio_lookup_list, list) {
if (table->dev_id && dev_id) {
/*
* Valid strings on both ends, must be identical to have
* a match
*/
if (!strcmp(table->dev_id, dev_id))
return table;
} else {
/*
* One of the pointers is NULL, so both must be to have
* a match
*/
if (dev_id == table->dev_id)
return table;
}
}
return NULL;
}
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
unsigned int idx, unsigned long *flags)
{
struct gpio_desc *desc = ERR_PTR(-ENOENT);
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
struct gpio_chip *gc;
guard(mutex)(&gpio_lookup_lock);
table = gpiod_find_lookup_table(dev);
if (!table)
return desc;
for (p = &table->table[0]; p->key; p++) {
/* idx must always match exactly */
if (p->idx != idx)
continue;
/* If the lookup entry has a con_id, require exact match */
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
continue;
if (p->chip_hwnum == U16_MAX) {
desc = gpio_name_to_desc(p->key);
if (desc) {
*flags = p->flags;
return desc;
}
dev_warn(dev, "cannot find GPIO line %s, deferring\n",
p->key);
return ERR_PTR(-EPROBE_DEFER);
}
struct gpio_device *gdev __free(gpio_device_put) =
gpio_device_find_by_label(p->key);
if (!gdev) {
/*
* As the lookup table indicates a chip with
* p->key should exist, assume it may
* still appear later and let the interested
* consumer be probed again or let the Deferred
* Probe infrastructure handle the error.
*/
dev_warn(dev, "cannot find GPIO chip %s, deferring\n",
p->key);
return ERR_PTR(-EPROBE_DEFER);
}
gc = gpio_device_get_chip(gdev);
if (gc->ngpio <= p->chip_hwnum) {
dev_err(dev,
"requested GPIO %u (%u) is out of range [0..%u] for chip %s\n",
idx, p->chip_hwnum, gc->ngpio - 1,
gc->label);
return ERR_PTR(-EINVAL);
}
desc = gpio_device_get_desc(gdev, p->chip_hwnum);
*flags = p->flags;
return desc;
}
return desc;
}
static int platform_gpio_count(struct device *dev, const char *con_id)
{
struct gpiod_lookup_table *table;
struct gpiod_lookup *p;
unsigned int count = 0;
scoped_guard(mutex, &gpio_lookup_lock) {
table = gpiod_find_lookup_table(dev);
if (!table)
return -ENOENT;
for (p = &table->table[0]; p->key; p++) {
if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) ||
(!con_id && !p->con_id))
count++;
}
}
if (!count)
return -ENOENT;
return count;
}
static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode,
struct device *consumer,
const char *con_id,
unsigned int idx,
enum gpiod_flags *flags,
unsigned long *lookupflags)
{
const char *name = function_name_or_default(con_id);
struct gpio_desc *desc = ERR_PTR(-ENOENT);
if (is_of_node(fwnode)) {
dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, name);
desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags);
} else if (is_acpi_node(fwnode)) {
dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, name);
desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags);
} else if (is_software_node(fwnode)) {
dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, name);
desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags);
}
return desc;
}
struct gpio_desc *gpiod_find_and_request(struct device *consumer,
struct fwnode_handle *fwnode,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags,
const char *label,
bool platform_lookup_allowed)
{
unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT;
const char *name = function_name_or_default(con_id);
/*
* scoped_guard() is implemented as a for loop, meaning static
* analyzers will complain about these two not being initialized.
*/
struct gpio_desc *desc = NULL;
int ret = 0;
scoped_guard(srcu, &gpio_devices_srcu) {
desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx,
&flags, &lookupflags);
if (gpiod_not_found(desc) && platform_lookup_allowed) {
/*
* Either we are not using DT or ACPI, or their lookup
* did not return a result. In that case, use platform
* lookup as a fallback.
*/
dev_dbg(consumer,
"using lookup tables for GPIO lookup\n");
desc = gpiod_find(consumer, con_id, idx, &lookupflags);
}
if (IS_ERR(desc)) {
dev_dbg(consumer, "No GPIO consumer %s found\n", name);
return desc;
}
/*
* If a connection label was passed use that, else attempt to use
* the device name as label
*/
ret = gpiod_request(desc, label);
}
if (ret) {
if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
return ERR_PTR(ret);
/*
* This happens when there are several consumers for
* the same GPIO line: we just return here without
* further initialization. It is a bit of a hack.
* This is necessary to support fixed regulators.
*
* FIXME: Make this more sane and safe.
*/
dev_info(consumer, "nonexclusive access to GPIO for %s\n", name);
return desc;
}
ret = gpiod_configure_flags(desc, con_id, lookupflags, flags);
if (ret < 0) {
gpiod_put(desc);
dev_err(consumer, "setup of GPIO %s failed: %d\n", name, ret);
return ERR_PTR(ret);
}
gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED);
return desc;
}
/**
* fwnode_gpiod_get_index - obtain a GPIO from firmware node
* @fwnode: handle of the firmware node
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain for the consumer
* @flags: GPIO initialization flags
* @label: label to attach to the requested GPIO
*
* This function can be used for drivers that get their configuration
* from opaque firmware.
*
* The function properly finds the corresponding GPIO using whatever is the
* underlying firmware interface and then makes sure that the GPIO
* descriptor is requested before it is returned to the caller.
*
* Returns:
* On successful request the GPIO pin is configured in accordance with
* provided @flags.
*
* In case of error an ERR_PTR() is returned.
*/
struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode,
const char *con_id,
int index,
enum gpiod_flags flags,
const char *label)
{
return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false);
}
EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index);
/**
* gpiod_count - return the number of GPIOs associated with a device / function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
*
* Returns:
* The number of GPIOs associated with a device / function or -ENOENT if no
* GPIO has been assigned to the requested function.
*/
int gpiod_count(struct device *dev, const char *con_id)
{
const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
int count = -ENOENT;
if (is_of_node(fwnode))
count = of_gpio_count(fwnode, con_id);
else if (is_acpi_node(fwnode))
count = acpi_gpio_count(fwnode, con_id);
else if (is_software_node(fwnode))
count = swnode_gpio_count(fwnode, con_id);
if (count < 0)
count = platform_gpio_count(dev, con_id);
return count;
}
EXPORT_SYMBOL_GPL(gpiod_count);
/**
* gpiod_get - obtain a GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* Returns:
* The GPIO descriptor corresponding to the function @con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get);
/**
* gpiod_get_optional - obtain an optional GPIO for a given GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get(), except that when no GPIO was assigned to
* the requested function it will return NULL. This is convenient for drivers
* that need to handle optional GPIOs.
*
* Returns:
* The GPIO descriptor corresponding to the function @con_id of device
* dev, NULL if no GPIO has been assigned to the requested function, or
* another IS_ERR() code if an error occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
return gpiod_get_index_optional(dev, con_id, 0, flags);
}
EXPORT_SYMBOL_GPL(gpiod_get_optional);
/**
* gpiod_configure_flags - helper function to configure a given GPIO
* @desc: gpio whose value will be assigned
* @con_id: function within the GPIO consumer
* @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
* of_find_gpio() or of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*
* Returns:
* 0 on success, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
unsigned long lflags, enum gpiod_flags dflags)
{
const char *name = function_name_or_default(con_id);
int ret;
if (lflags & GPIO_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
if (lflags & GPIO_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
/*
* This enforces open drain mode from the consumer side.
* This is necessary for some busses like I2C, but the lookup
* should *REALLY* have specified them as open drain in the
* first place, so print a little warning here.
*/
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
gpiod_warn(desc,
"enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
}
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) ||
((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) ||
((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) {
gpiod_err(desc,
"multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n");
return -EINVAL;
}
if (lflags & GPIO_PULL_UP)
set_bit(FLAG_PULL_UP, &desc->flags);
else if (lflags & GPIO_PULL_DOWN)
set_bit(FLAG_PULL_DOWN, &desc->flags);
else if (lflags & GPIO_PULL_DISABLE)
set_bit(FLAG_BIAS_DISABLE, &desc->flags);
ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY));
if (ret < 0)
return ret;
/* No particular flag request, return here... */
if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) {
gpiod_dbg(desc, "no flags found for GPIO %s\n", name);
return 0;
}
/* Process flags */
if (dflags & GPIOD_FLAGS_BIT_DIR_OUT)
ret = gpiod_direction_output(desc,
!!(dflags & GPIOD_FLAGS_BIT_DIR_VAL));
else
ret = gpiod_direction_input(desc);
return ret;
}
/**
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @idx: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This variant of gpiod_get() allows to access GPIOs other than the first
* defined one for functions that define several GPIOs.
*
* Returns:
* A valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
const char *con_id,
unsigned int idx,
enum gpiod_flags flags)
{
struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL;
const char *devname = dev ? dev_name(dev) : "?";
const char *label = con_id ?: devname;
return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true);
}
EXPORT_SYMBOL_GPL(gpiod_get_index);
/**
* gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @index: index of the GPIO to obtain in the consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_index(), except that when no GPIO with the
* specified index was assigned to the requested function it will return NULL.
* This is convenient for drivers that need to handle optional GPIOs.
*
* Returns:
* A valid GPIO descriptor, NULL if no GPIO has been assigned to the
* requested function and/or index, or another IS_ERR() code if an error
* occurred while trying to acquire the GPIO.
*/
struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev,
const char *con_id,
unsigned int index,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
desc = gpiod_get_index(dev, con_id, index, flags);
if (gpiod_not_found(desc))
return NULL;
return desc;
}
EXPORT_SYMBOL_GPL(gpiod_get_index_optional);
/**
* gpiod_hog - Hog the specified GPIO desc given the provided flags
* @desc: gpio whose value will be assigned
* @name: gpio line name
* @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from
* of_find_gpio() or of_get_gpio_hog()
* @dflags: gpiod_flags - optional GPIO initialization flags
*
* Returns:
* 0 on success, or negative errno on failure.
*/
int gpiod_hog(struct gpio_desc *desc, const char *name,
unsigned long lflags, enum gpiod_flags dflags)
{
struct gpio_device *gdev = desc->gdev;
struct gpio_desc *local_desc;
int hwnum;
int ret;
CLASS(gpio_chip_guard, guard)(desc);
if (!guard.gc)
return -ENODEV;
if (test_and_set_bit(FLAG_IS_HOGGED, &desc->flags))
return 0;
hwnum = gpio_chip_hwgpio(desc);
local_desc = gpiochip_request_own_desc(guard.gc, hwnum, name,
lflags, dflags);
if (IS_ERR(local_desc)) {
clear_bit(FLAG_IS_HOGGED, &desc->flags);
ret = PTR_ERR(local_desc);
pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n",
name, gdev->label, hwnum, ret);
return ret;
}
gpiod_dbg(desc, "hogged as %s%s\n",
(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input",
(dflags & GPIOD_FLAGS_BIT_DIR_OUT) ?
(dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : "");
return 0;
}
/**
* gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog
* @gc: gpio chip to act on
*/
static void gpiochip_free_hogs(struct gpio_chip *gc)
{
struct gpio_desc *desc;
for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED)
gpiochip_free_own_desc(desc);
}
/**
* gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This function acquires all the GPIOs defined under a given function.
*
* Returns:
* The GPIO descriptors corresponding to the function @con_id of device
* dev, -ENOENT if no GPIO has been assigned to the requested function,
* or another IS_ERR() code if an error occurred while trying to acquire
* the GPIOs.
*/
struct gpio_descs *__must_check gpiod_get_array(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_desc *desc;
struct gpio_descs *descs;
struct gpio_array *array_info = NULL;
struct gpio_chip *gc;
int count, bitmap_size;
size_t descs_size;
count = gpiod_count(dev, con_id);
if (count < 0)
return ERR_PTR(count);
descs_size = struct_size(descs, desc, count);
descs = kzalloc(descs_size, GFP_KERNEL);
if (!descs)
return ERR_PTR(-ENOMEM);
for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) {
desc = gpiod_get_index(dev, con_id, descs->ndescs, flags);
if (IS_ERR(desc)) {
gpiod_put_array(descs);
return ERR_CAST(desc);
}
descs->desc[descs->ndescs] = desc;
gc = gpiod_to_chip(desc);
/*
* If pin hardware number of array member 0 is also 0, select
* its chip as a candidate for fast bitmap processing path.
*/
if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) {
struct gpio_descs *array;
bitmap_size = BITS_TO_LONGS(gc->ngpio > count ?
gc->ngpio : count);
array = krealloc(descs, descs_size +
struct_size(array_info, invert_mask, 3 * bitmap_size),
GFP_KERNEL | __GFP_ZERO);
if (!array) {
gpiod_put_array(descs);
return ERR_PTR(-ENOMEM);
}
descs = array;
array_info = (void *)descs + descs_size;
array_info->get_mask = array_info->invert_mask +
bitmap_size;
array_info->set_mask = array_info->get_mask +
bitmap_size;
array_info->desc = descs->desc;
array_info->size = count;
array_info->chip = gc;
bitmap_set(array_info->get_mask, descs->ndescs,
count - descs->ndescs);
bitmap_set(array_info->set_mask, descs->ndescs,
count - descs->ndescs);
descs->info = array_info;
}
/* If there is no cache for fast bitmap processing path, continue */
if (!array_info)
continue;
/* Unmark array members which don't belong to the 'fast' chip */
if (array_info->chip != gc) {
__clear_bit(descs->ndescs, array_info->get_mask);
__clear_bit(descs->ndescs, array_info->set_mask);
}
/*
* Detect array members which belong to the 'fast' chip
* but their pins are not in hardware order.
*/
else if (gpio_chip_hwgpio(desc) != descs->ndescs) {
/*
* Don't use fast path if all array members processed so
* far belong to the same chip as this one but its pin
* hardware number is different from its array index.
*/
if (bitmap_full(array_info->get_mask, descs->ndescs)) {
array_info = NULL;
} else {
__clear_bit(descs->ndescs,
array_info->get_mask);
__clear_bit(descs->ndescs,
array_info->set_mask);
}
} else {
/* Exclude open drain or open source from fast output */
if (gpiochip_line_is_open_drain(gc, descs->ndescs) ||
gpiochip_line_is_open_source(gc, descs->ndescs))
__clear_bit(descs->ndescs,
array_info->set_mask);
/* Identify 'fast' pins which require invertion */
if (gpiod_is_active_low(desc))
__set_bit(descs->ndescs,
array_info->invert_mask);
}
}
if (array_info)
dev_dbg(dev,
"GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n",
array_info->chip->label, array_info->size,
*array_info->get_mask, *array_info->set_mask,
*array_info->invert_mask);
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array);
/**
* gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO
* function
* @dev: GPIO consumer, can be NULL for system-global GPIOs
* @con_id: function within the GPIO consumer
* @flags: optional GPIO initialization flags
*
* This is equivalent to gpiod_get_array(), except that when no GPIO was
* assigned to the requested function it will return NULL.
*
* Returns:
* The GPIO descriptors corresponding to the function @con_id of device
* dev, NULL if no GPIO has been assigned to the requested function,
* or another IS_ERR() code if an error occurred while trying to acquire
* the GPIOs.
*/
struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev,
const char *con_id,
enum gpiod_flags flags)
{
struct gpio_descs *descs;
descs = gpiod_get_array(dev, con_id, flags);
if (gpiod_not_found(descs))
return NULL;
return descs;
}
EXPORT_SYMBOL_GPL(gpiod_get_array_optional);
/**
* gpiod_put - dispose of a GPIO descriptor
* @desc: GPIO descriptor to dispose of
*
* No descriptor can be used after gpiod_put() has been called on it.
*/
void gpiod_put(struct gpio_desc *desc)
{
if (desc)
gpiod_free(desc);
}
EXPORT_SYMBOL_GPL(gpiod_put);
/**
* gpiod_put_array - dispose of multiple GPIO descriptors
* @descs: struct gpio_descs containing an array of descriptors
*/
void gpiod_put_array(struct gpio_descs *descs)
{
unsigned int i;
for (i = 0; i < descs->ndescs; i++)
gpiod_put(descs->desc[i]);
kfree(descs);
}
EXPORT_SYMBOL_GPL(gpiod_put_array);
static int gpio_stub_drv_probe(struct device *dev)
{
/*
* The DT node of some GPIO chips have a "compatible" property, but
* never have a struct device added and probed by a driver to register
* the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause
* the consumers of the GPIO chip to get probe deferred forever because
* they will be waiting for a device associated with the GPIO chip
* firmware node to get added and bound to a driver.
*
* To allow these consumers to probe, we associate the struct
* gpio_device of the GPIO chip with the firmware node and then simply
* bind it to this stub driver.
*/
return 0;
}
static struct device_driver gpio_stub_drv = {
.name = "gpio_stub_drv",
.bus = &gpio_bus_type,
.probe = gpio_stub_drv_probe,
};
static int __init gpiolib_dev_init(void)
{
int ret;
/* Register GPIO sysfs bus */
ret = bus_register(&gpio_bus_type);
if (ret < 0) {
pr_err("gpiolib: could not register GPIO bus type\n");
return ret;
}
ret = driver_register(&gpio_stub_drv);
if (ret < 0) {
pr_err("gpiolib: could not register GPIO stub driver\n");
bus_unregister(&gpio_bus_type);
return ret;
}
ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME);
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
driver_unregister(&gpio_stub_drv);
bus_unregister(&gpio_bus_type);
return ret;
}
gpiolib_initialized = true;
gpiochip_setup_devs();
#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
return ret;
}
core_initcall(gpiolib_dev_init);
#ifdef CONFIG_DEBUG_FS
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev)
{
bool active_low, is_irq, is_out;
unsigned int gpio = gdev->base;
struct gpio_desc *desc;
struct gpio_chip *gc;
int value;
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (!gc) {
seq_puts(s, "Underlying GPIO chip is gone\n");
return;
}
for_each_gpio_desc(gc, desc) {
guard(srcu)(&desc->gdev->desc_srcu);
is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags);
if (is_irq || test_bit(FLAG_REQUESTED, &desc->flags)) {
gpiod_get_direction(desc);
is_out = test_bit(FLAG_IS_OUT, &desc->flags);
value = gpio_chip_get_value(gc, desc);
active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags);
seq_printf(s, " gpio-%-3u (%-20.20s|%-20.20s) %s %s %s%s\n",
gpio, desc->name ?: "", gpiod_get_label(desc),
is_out ? "out" : "in ",
value >= 0 ? (value ? "hi" : "lo") : "? ",
is_irq ? "IRQ " : "",
active_low ? "ACTIVE LOW" : "");
} else if (desc->name) {
seq_printf(s, " gpio-%-3u (%-20.20s)\n", gpio, desc->name);
}
gpio++;
}
}
struct gpiolib_seq_priv {
bool newline;
int idx;
};
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
{
struct gpiolib_seq_priv *priv;
struct gpio_device *gdev;
loff_t index = *pos;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return NULL;
s->private = priv;
priv->idx = srcu_read_lock(&gpio_devices_srcu);
list_for_each_entry_srcu(gdev, &gpio_devices, list,
srcu_read_lock_held(&gpio_devices_srcu)) {
if (index-- == 0)
return gdev;
}
return NULL;
}
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
struct gpiolib_seq_priv *priv = s->private;
struct gpio_device *gdev = v, *next;
next = list_entry_rcu(gdev->list.next, struct gpio_device, list);
gdev = &next->list == &gpio_devices ? NULL : next;
priv->newline = true;
++*pos;
return gdev;
}
static void gpiolib_seq_stop(struct seq_file *s, void *v)
{
struct gpiolib_seq_priv *priv = s->private;
srcu_read_unlock(&gpio_devices_srcu, priv->idx);
kfree(priv);
}
static int gpiolib_seq_show(struct seq_file *s, void *v)
{
struct gpiolib_seq_priv *priv = s->private;
struct gpio_device *gdev = v;
struct gpio_chip *gc;
struct device *parent;
guard(srcu)(&gdev->srcu);
gc = srcu_dereference(gdev->chip, &gdev->srcu);
if (!gc) {
seq_printf(s, "%s%s: (dangling chip)",
priv->newline ? "\n" : "",
dev_name(&gdev->dev));
return 0;
}
seq_printf(s, "%s%s: GPIOs %u-%u", priv->newline ? "\n" : "",
dev_name(&gdev->dev),
gdev->base, gdev->base + gdev->ngpio - 1);
parent = gc->parent;
if (parent)
seq_printf(s, ", parent: %s/%s",
parent->bus ? parent->bus->name : "no-bus",
dev_name(parent));
if (gc->label)
seq_printf(s, ", %s", gc->label);
if (gc->can_sleep)
seq_printf(s, ", can sleep");
seq_printf(s, ":\n");
if (gc->dbg_show)
gc->dbg_show(s, gc);
else
gpiolib_dbg_show(s, gdev);
return 0;
}
static const struct seq_operations gpiolib_sops = {
.start = gpiolib_seq_start,
.next = gpiolib_seq_next,
.stop = gpiolib_seq_stop,
.show = gpiolib_seq_show,
};
DEFINE_SEQ_ATTRIBUTE(gpiolib);
static int __init gpiolib_debugfs_init(void)
{
/* /sys/kernel/debug/gpio */
debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops);
return 0;
}
subsys_initcall(gpiolib_debugfs_init);
#endif /* DEBUG_FS */
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