// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/arch/arm/common/amba.c
*
* Copyright (C) 2003 Deep Blue Solutions Ltd, All Rights Reserved.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/pm.h>
#include <linux/pm_runtime.h>
#include <linux/pm_domain.h>
#include <linux/amba/bus.h>
#include <linux/sizes.h>
#include <linux/limits.h>
#include <linux/clk/clk-conf.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/reset.h>
#include <linux/of_irq.h>
#include <linux/of_device.h>
#include <linux/acpi.h>
#include <linux/iommu.h>
#include <linux/dma-map-ops.h>
#define to_amba_driver(d) container_of_const(d, struct amba_driver, drv)
/* called on periphid match and class 0x9 coresight device. */
static int
amba_cs_uci_id_match(const struct amba_id *table, struct amba_device *dev)
{
int ret = 0;
struct amba_cs_uci_id *uci;
uci = table->data;
/* no table data or zero mask - return match on periphid */
if (!uci || (uci->devarch_mask == 0))
return 1;
/* test against read devtype and masked devarch value */
ret = (dev->uci.devtype == uci->devtype) &&
((dev->uci.devarch & uci->devarch_mask) == uci->devarch);
return ret;
}
static const struct amba_id *
amba_lookup(const struct amba_id *table, struct amba_device *dev)
{
while (table->mask) {
if (((dev->periphid & table->mask) == table->id) &&
((dev->cid != CORESIGHT_CID) ||
(amba_cs_uci_id_match(table, dev))))
return table;
table++;
}
return NULL;
}
static int amba_get_enable_pclk(struct amba_device *pcdev)
{
int ret;
pcdev->pclk = clk_get(&pcdev->dev, "apb_pclk");
if (IS_ERR(pcdev->pclk))
return PTR_ERR(pcdev->pclk);
ret = clk_prepare_enable(pcdev->pclk);
if (ret)
clk_put(pcdev->pclk);
return ret;
}
static void amba_put_disable_pclk(struct amba_device *pcdev)
{
clk_disable_unprepare(pcdev->pclk);
clk_put(pcdev->pclk);
}
static ssize_t driver_override_show(struct device *_dev,
struct device_attribute *attr, char *buf)
{
struct amba_device *dev = to_amba_device(_dev);
ssize_t len;
device_lock(_dev);
len = sprintf(buf, "%s\n", dev->driver_override);
device_unlock(_dev);
return len;
}
static ssize_t driver_override_store(struct device *_dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct amba_device *dev = to_amba_device(_dev);
int ret;
ret = driver_set_override(_dev, &dev->driver_override, buf, count);
if (ret)
return ret;
return count;
}
static DEVICE_ATTR_RW(driver_override);
#define amba_attr_func(name,fmt,arg...) \
static ssize_t name##_show(struct device *_dev, \
struct device_attribute *attr, char *buf) \
{ \
struct amba_device *dev = to_amba_device(_dev); \
return sprintf(buf, fmt, arg); \
} \
static DEVICE_ATTR_RO(name)
amba_attr_func(id, "%08x\n", dev->periphid);
amba_attr_func(resource, "\t%016llx\t%016llx\t%016lx\n",
(unsigned long long)dev->res.start, (unsigned long long)dev->res.end,
dev->res.flags);
static struct attribute *amba_dev_attrs[] = {
&dev_attr_id.attr,
&dev_attr_resource.attr,
&dev_attr_driver_override.attr,
NULL,
};
ATTRIBUTE_GROUPS(amba_dev);
static int amba_read_periphid(struct amba_device *dev)
{
struct reset_control *rstc;
u32 size, pid, cid;
void __iomem *tmp;
int i, ret;
ret = dev_pm_domain_attach(&dev->dev, true);
if (ret) {
dev_dbg(&dev->dev, "can't get PM domain: %d\n", ret);
goto err_out;
}
ret = amba_get_enable_pclk(dev);
if (ret) {
dev_dbg(&dev->dev, "can't get pclk: %d\n", ret);
goto err_pm;
}
/*
* Find reset control(s) of the amba bus and de-assert them.
*/
rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node);
if (IS_ERR(rstc)) {
ret = PTR_ERR(rstc);
if (ret != -EPROBE_DEFER)
dev_err(&dev->dev, "can't get reset: %d\n", ret);
goto err_clk;
}
reset_control_deassert(rstc);
reset_control_put(rstc);
size = resource_size(&dev->res);
tmp = ioremap(dev->res.start, size);
if (!tmp) {
ret = -ENOMEM;
goto err_clk;
}
/*
* Read pid and cid based on size of resource
* they are located at end of region
*/
for (pid = 0, i = 0; i < 4; i++)
pid |= (readl(tmp + size - 0x20 + 4 * i) & 255) << (i * 8);
for (cid = 0, i = 0; i < 4; i++)
cid |= (readl(tmp + size - 0x10 + 4 * i) & 255) << (i * 8);
if (cid == CORESIGHT_CID) {
/* set the base to the start of the last 4k block */
void __iomem *csbase = tmp + size - 4096;
dev->uci.devarch = readl(csbase + UCI_REG_DEVARCH_OFFSET);
dev->uci.devtype = readl(csbase + UCI_REG_DEVTYPE_OFFSET) & 0xff;
}
if (cid == AMBA_CID || cid == CORESIGHT_CID) {
dev->periphid = pid;
dev->cid = cid;
}
if (!dev->periphid)
ret = -ENODEV;
iounmap(tmp);
err_clk:
amba_put_disable_pclk(dev);
err_pm:
dev_pm_domain_detach(&dev->dev, true);
err_out:
return ret;
}
static int amba_match(struct device *dev, const struct device_driver *drv)
{
struct amba_device *pcdev = to_amba_device(dev);
const struct amba_driver *pcdrv = to_amba_driver(drv);
mutex_lock(&pcdev->periphid_lock);
if (!pcdev->periphid) {
int ret = amba_read_periphid(pcdev);
/*
* Returning any error other than -EPROBE_DEFER from bus match
* can cause driver registration failure. So, if there's a
* permanent failure in reading pid and cid, simply map it to
* -EPROBE_DEFER.
*/
if (ret) {
mutex_unlock(&pcdev->periphid_lock);
return -EPROBE_DEFER;
}
dev_set_uevent_suppress(dev, false);
kobject_uevent(&dev->kobj, KOBJ_ADD);
}
mutex_unlock(&pcdev->periphid_lock);
/* When driver_override is set, only bind to the matching driver */
if (pcdev->driver_override)
return !strcmp(pcdev->driver_override, drv->name);
return amba_lookup(pcdrv->id_table, pcdev) != NULL;
}
static int amba_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
const struct amba_device *pcdev = to_amba_device(dev);
int retval = 0;
retval = add_uevent_var(env, "AMBA_ID=%08x", pcdev->periphid);
if (retval)
return retval;
retval = add_uevent_var(env, "MODALIAS=amba:d%08X", pcdev->periphid);
return retval;
}
static int of_amba_device_decode_irq(struct amba_device *dev)
{
struct device_node *node = dev->dev.of_node;
int i, irq = 0;
if (IS_ENABLED(CONFIG_OF_IRQ) && node) {
/* Decode the IRQs and address ranges */
for (i = 0; i < AMBA_NR_IRQS; i++) {
irq = of_irq_get(node, i);
if (irq < 0) {
if (irq == -EPROBE_DEFER)
return irq;
irq = 0;
}
dev->irq[i] = irq;
}
}
return 0;
}
/*
* These are the device model conversion veneers; they convert the
* device model structures to our more specific structures.
*/
static int amba_probe(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
struct amba_driver *pcdrv = to_amba_driver(dev->driver);
const struct amba_id *id = amba_lookup(pcdrv->id_table, pcdev);
int ret;
do {
ret = of_amba_device_decode_irq(pcdev);
if (ret)
break;
ret = of_clk_set_defaults(dev->of_node, false);
if (ret < 0)
break;
ret = dev_pm_domain_attach(dev, true);
if (ret)
break;
ret = amba_get_enable_pclk(pcdev);
if (ret) {
dev_pm_domain_detach(dev, true);
break;
}
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
ret = pcdrv->probe(pcdev, id);
if (ret == 0)
break;
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
pm_runtime_put_noidle(dev);
amba_put_disable_pclk(pcdev);
dev_pm_domain_detach(dev, true);
} while (0);
return ret;
}
static void amba_remove(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
struct amba_driver *drv = to_amba_driver(dev->driver);
pm_runtime_get_sync(dev);
if (drv->remove)
drv->remove(pcdev);
pm_runtime_put_noidle(dev);
/* Undo the runtime PM settings in amba_probe() */
pm_runtime_disable(dev);
pm_runtime_set_suspended(dev);
pm_runtime_put_noidle(dev);
amba_put_disable_pclk(pcdev);
dev_pm_domain_detach(dev, true);
}
static void amba_shutdown(struct device *dev)
{
struct amba_driver *drv;
if (!dev->driver)
return;
drv = to_amba_driver(dev->driver);
if (drv->shutdown)
drv->shutdown(to_amba_device(dev));
}
static int amba_dma_configure(struct device *dev)
{
struct amba_driver *drv = to_amba_driver(dev->driver);
enum dev_dma_attr attr;
int ret = 0;
if (dev->of_node) {
ret = of_dma_configure(dev, dev->of_node, true);
} else if (has_acpi_companion(dev)) {
attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
ret = acpi_dma_configure(dev, attr);
}
if (!ret && !drv->driver_managed_dma) {
ret = iommu_device_use_default_domain(dev);
if (ret)
arch_teardown_dma_ops(dev);
}
return ret;
}
static void amba_dma_cleanup(struct device *dev)
{
struct amba_driver *drv = to_amba_driver(dev->driver);
if (!drv->driver_managed_dma)
iommu_device_unuse_default_domain(dev);
}
#ifdef CONFIG_PM
/*
* Hooks to provide runtime PM of the pclk (bus clock). It is safe to
* enable/disable the bus clock at runtime PM suspend/resume as this
* does not result in loss of context.
*/
static int amba_pm_runtime_suspend(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
int ret = pm_generic_runtime_suspend(dev);
if (ret == 0 && dev->driver) {
if (pm_runtime_is_irq_safe(dev))
clk_disable(pcdev->pclk);
else
clk_disable_unprepare(pcdev->pclk);
}
return ret;
}
static int amba_pm_runtime_resume(struct device *dev)
{
struct amba_device *pcdev = to_amba_device(dev);
int ret;
if (dev->driver) {
if (pm_runtime_is_irq_safe(dev))
ret = clk_enable(pcdev->pclk);
else
ret = clk_prepare_enable(pcdev->pclk);
/* Failure is probably fatal to the system, but... */
if (ret)
return ret;
}
return pm_generic_runtime_resume(dev);
}
#endif /* CONFIG_PM */
static const struct dev_pm_ops amba_pm = {
SET_RUNTIME_PM_OPS(
amba_pm_runtime_suspend,
amba_pm_runtime_resume,
NULL
)
};
/*
* Primecells are part of the Advanced Microcontroller Bus Architecture,
* so we call the bus "amba".
* DMA configuration for platform and AMBA bus is same. So here we reuse
* platform's DMA config routine.
*/
struct bus_type amba_bustype = {
.name = "amba",
.dev_groups = amba_dev_groups,
.match = amba_match,
.uevent = amba_uevent,
.probe = amba_probe,
.remove = amba_remove,
.shutdown = amba_shutdown,
.dma_configure = amba_dma_configure,
.dma_cleanup = amba_dma_cleanup,
.pm = &amba_pm,
};
EXPORT_SYMBOL_GPL(amba_bustype);
static int __init amba_init(void)
{
return bus_register(&amba_bustype);
}
postcore_initcall(amba_init);
static int amba_proxy_probe(struct amba_device *adev,
const struct amba_id *id)
{
WARN(1, "Stub driver should never match any device.\n");
return -ENODEV;
}
static const struct amba_id amba_stub_drv_ids[] = {
{ 0, 0 },
};
static struct amba_driver amba_proxy_drv = {
.drv = {
.name = "amba-proxy",
},
.probe = amba_proxy_probe,
.id_table = amba_stub_drv_ids,
};
static int __init amba_stub_drv_init(void)
{
if (!IS_ENABLED(CONFIG_MODULES))
return 0;
/*
* The amba_match() function will get called only if there is at least
* one amba driver registered. If all amba drivers are modules and are
* only loaded based on uevents, then we'll hit a chicken-and-egg
* situation where amba_match() is waiting on drivers and drivers are
* waiting on amba_match(). So, register a stub driver to make sure
* amba_match() is called even if no amba driver has been registered.
*/
return __amba_driver_register(&amba_proxy_drv, NULL);
}
late_initcall_sync(amba_stub_drv_init);
/**
* __amba_driver_register - register an AMBA device driver
* @drv: amba device driver structure
* @owner: owning module/driver
*
* Register an AMBA device driver with the Linux device model
* core. If devices pre-exist, the drivers probe function will
* be called.
*/
int __amba_driver_register(struct amba_driver *drv,
struct module *owner)
{
if (!drv->probe)
return -EINVAL;
drv->drv.owner = owner;
drv->drv.bus = &amba_bustype;
return driver_register(&drv->drv);
}
EXPORT_SYMBOL(__amba_driver_register);
/**
* amba_driver_unregister - remove an AMBA device driver
* @drv: AMBA device driver structure to remove
*
* Unregister an AMBA device driver from the Linux device
* model. The device model will call the drivers remove function
* for each device the device driver is currently handling.
*/
void amba_driver_unregister(struct amba_driver *drv)
{
driver_unregister(&drv->drv);
}
EXPORT_SYMBOL(amba_driver_unregister);
static void amba_device_release(struct device *dev)
{
struct amba_device *d = to_amba_device(dev);
fwnode_handle_put(dev_fwnode(&d->dev));
if (d->res.parent)
release_resource(&d->res);
mutex_destroy(&d->periphid_lock);
kfree(d);
}
/**
* amba_device_add - add a previously allocated AMBA device structure
* @dev: AMBA device allocated by amba_device_alloc
* @parent: resource parent for this devices resources
*
* Claim the resource, and read the device cell ID if not already
* initialized. Register the AMBA device with the Linux device
* manager.
*/
int amba_device_add(struct amba_device *dev, struct resource *parent)
{
int ret;
fwnode_handle_get(dev_fwnode(&dev->dev));
ret = request_resource(parent, &dev->res);
if (ret)
return ret;
/* If primecell ID isn't hard-coded, figure it out */
if (!dev->periphid) {
/*
* AMBA device uevents require reading its pid and cid
* registers. To do this, the device must be on, clocked and
* out of reset. However in some cases those resources might
* not yet be available. If that's the case, we suppress the
* generation of uevents until we can read the pid and cid
* registers. See also amba_match().
*/
if (amba_read_periphid(dev))
dev_set_uevent_suppress(&dev->dev, true);
}
ret = device_add(&dev->dev);
if (ret)
release_resource(&dev->res);
return ret;
}
EXPORT_SYMBOL_GPL(amba_device_add);
static void amba_device_initialize(struct amba_device *dev, const char *name)
{
device_initialize(&dev->dev);
if (name)
dev_set_name(&dev->dev, "%s", name);
dev->dev.release = amba_device_release;
dev->dev.bus = &amba_bustype;
dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
dev->dev.dma_parms = &dev->dma_parms;
dev->res.name = dev_name(&dev->dev);
mutex_init(&dev->periphid_lock);
}
/**
* amba_device_alloc - allocate an AMBA device
* @name: sysfs name of the AMBA device
* @base: base of AMBA device
* @size: size of AMBA device
*
* Allocate and initialize an AMBA device structure. Returns %NULL
* on failure.
*/
struct amba_device *amba_device_alloc(const char *name, resource_size_t base,
size_t size)
{
struct amba_device *dev;
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev) {
amba_device_initialize(dev, name);
dev->res.start = base;
dev->res.end = base + size - 1;
dev->res.flags = IORESOURCE_MEM;
}
return dev;
}
EXPORT_SYMBOL_GPL(amba_device_alloc);
/**
* amba_device_register - register an AMBA device
* @dev: AMBA device to register
* @parent: parent memory resource
*
* Setup the AMBA device, reading the cell ID if present.
* Claim the resource, and register the AMBA device with
* the Linux device manager.
*/
int amba_device_register(struct amba_device *dev, struct resource *parent)
{
amba_device_initialize(dev, dev->dev.init_name);
dev->dev.init_name = NULL;
return amba_device_add(dev, parent);
}
EXPORT_SYMBOL(amba_device_register);
/**
* amba_device_put - put an AMBA device
* @dev: AMBA device to put
*/
void amba_device_put(struct amba_device *dev)
{
put_device(&dev->dev);
}
EXPORT_SYMBOL_GPL(amba_device_put);
/**
* amba_device_unregister - unregister an AMBA device
* @dev: AMBA device to remove
*
* Remove the specified AMBA device from the Linux device
* manager. All files associated with this object will be
* destroyed, and device drivers notified that the device has
* been removed. The AMBA device's resources including
* the amba_device structure will be freed once all
* references to it have been dropped.
*/
void amba_device_unregister(struct amba_device *dev)
{
device_unregister(&dev->dev);
}
EXPORT_SYMBOL(amba_device_unregister);
/**
* amba_request_regions - request all mem regions associated with device
* @dev: amba_device structure for device
* @name: name, or NULL to use driver name
*/
int amba_request_regions(struct amba_device *dev, const char *name)
{
int ret = 0;
u32 size;
if (!name)
name = dev->dev.driver->name;
size = resource_size(&dev->res);
if (!request_mem_region(dev->res.start, size, name))
ret = -EBUSY;
return ret;
}
EXPORT_SYMBOL(amba_request_regions);
/**
* amba_release_regions - release mem regions associated with device
* @dev: amba_device structure for device
*
* Release regions claimed by a successful call to amba_request_regions.
*/
void amba_release_regions(struct amba_device *dev)
{
u32 size;
size = resource_size(&dev->res);
release_mem_region(dev->res.start, size);
}
EXPORT_SYMBOL(amba_release_regions);
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