/*
* Support for the GPIO/IRQ expander chips present on several HTC phones.
* These are implemented in CPLD chips present on the board.
*
* Copyright (c) 2007 Kevin O'Connor <[email protected]>
* Copyright (c) 2007 Philipp Zabel <[email protected]>
*
* This file may be distributed under the terms of the GNU GPL license.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/platform_data/gpio-htc-egpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/gpio/driver.h>
struct egpio_chip {
int reg_start;
int cached_values;
unsigned long is_out;
struct device *dev;
struct gpio_chip chip;
};
struct egpio_info {
spinlock_t lock;
/* iomem info */
void __iomem *base_addr;
int bus_shift; /* byte shift */
int reg_shift; /* bit shift */
int reg_mask;
/* irq info */
int ack_register;
int ack_write;
u16 irqs_enabled;
uint irq_start;
int nirqs;
uint chained_irq;
/* egpio info */
struct egpio_chip *chip;
int nchips;
};
static inline void egpio_writew(u16 value, struct egpio_info *ei, int reg)
{
writew(value, ei->base_addr + (reg << ei->bus_shift));
}
static inline u16 egpio_readw(struct egpio_info *ei, int reg)
{
return readw(ei->base_addr + (reg << ei->bus_shift));
}
/*
* IRQs
*/
static inline void ack_irqs(struct egpio_info *ei)
{
egpio_writew(ei->ack_write, ei, ei->ack_register);
pr_debug("EGPIO ack - write %x to base+%x\n",
ei->ack_write, ei->ack_register << ei->bus_shift);
}
static void egpio_ack(struct irq_data *data)
{
}
/* There does not appear to be a way to proactively mask interrupts
* on the egpio chip itself. So, we simply ignore interrupts that
* aren't desired. */
static void egpio_mask(struct irq_data *data)
{
struct egpio_info *ei = irq_data_get_irq_chip_data(data);
ei->irqs_enabled &= ~(1 << (data->irq - ei->irq_start));
pr_debug("EGPIO mask %d %04x\n", data->irq, ei->irqs_enabled);
}
static void egpio_unmask(struct irq_data *data)
{
struct egpio_info *ei = irq_data_get_irq_chip_data(data);
ei->irqs_enabled |= 1 << (data->irq - ei->irq_start);
pr_debug("EGPIO unmask %d %04x\n", data->irq, ei->irqs_enabled);
}
static struct irq_chip egpio_muxed_chip = {
.name = "htc-egpio",
.irq_ack = egpio_ack,
.irq_mask = egpio_mask,
.irq_unmask = egpio_unmask,
};
static void egpio_handler(struct irq_desc *desc)
{
struct egpio_info *ei = irq_desc_get_handler_data(desc);
int irqpin;
/* Read current pins. */
unsigned long readval = egpio_readw(ei, ei->ack_register);
pr_debug("IRQ reg: %x\n", (unsigned int)readval);
/* Ack/unmask interrupts. */
ack_irqs(ei);
/* Process all set pins. */
readval &= ei->irqs_enabled;
for_each_set_bit(irqpin, &readval, ei->nirqs) {
/* Run irq handler */
pr_debug("got IRQ %d\n", irqpin);
generic_handle_irq(ei->irq_start + irqpin);
}
}
static inline int egpio_pos(struct egpio_info *ei, int bit)
{
return bit >> ei->reg_shift;
}
static inline int egpio_bit(struct egpio_info *ei, int bit)
{
return 1 << (bit & ((1 << ei->reg_shift)-1));
}
/*
* Input pins
*/
static int egpio_get(struct gpio_chip *chip, unsigned offset)
{
struct egpio_chip *egpio;
struct egpio_info *ei;
unsigned bit;
int reg;
int value;
pr_debug("egpio_get_value(%d)\n", chip->base + offset);
egpio = gpiochip_get_data(chip);
ei = dev_get_drvdata(egpio->dev);
bit = egpio_bit(ei, offset);
reg = egpio->reg_start + egpio_pos(ei, offset);
if (test_bit(offset, &egpio->is_out)) {
return !!(egpio->cached_values & (1 << offset));
} else {
value = egpio_readw(ei, reg);
pr_debug("readw(%p + %x) = %x\n",
ei->base_addr, reg << ei->bus_shift, value);
return !!(value & bit);
}
}
static int egpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct egpio_chip *egpio;
egpio = gpiochip_get_data(chip);
return test_bit(offset, &egpio->is_out) ? -EINVAL : 0;
}
/*
* Output pins
*/
static void egpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
unsigned long flag;
struct egpio_chip *egpio;
struct egpio_info *ei;
int pos;
int reg;
int shift;
pr_debug("egpio_set(%s, %d(%d), %d)\n",
chip->label, offset, offset+chip->base, value);
egpio = gpiochip_get_data(chip);
ei = dev_get_drvdata(egpio->dev);
pos = egpio_pos(ei, offset);
reg = egpio->reg_start + pos;
shift = pos << ei->reg_shift;
pr_debug("egpio %s: reg %d = 0x%04x\n", value ? "set" : "clear",
reg, (egpio->cached_values >> shift) & ei->reg_mask);
spin_lock_irqsave(&ei->lock, flag);
if (value)
egpio->cached_values |= (1 << offset);
else
egpio->cached_values &= ~(1 << offset);
egpio_writew((egpio->cached_values >> shift) & ei->reg_mask, ei, reg);
spin_unlock_irqrestore(&ei->lock, flag);
}
static int egpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct egpio_chip *egpio;
egpio = gpiochip_get_data(chip);
if (test_bit(offset, &egpio->is_out)) {
egpio_set(chip, offset, value);
return 0;
} else {
return -EINVAL;
}
}
static int egpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
struct egpio_chip *egpio;
egpio = gpiochip_get_data(chip);
if (test_bit(offset, &egpio->is_out))
return GPIO_LINE_DIRECTION_OUT;
return GPIO_LINE_DIRECTION_IN;
}
static void egpio_write_cache(struct egpio_info *ei)
{
int i;
struct egpio_chip *egpio;
int shift;
for (i = 0; i < ei->nchips; i++) {
egpio = &(ei->chip[i]);
if (!egpio->is_out)
continue;
for (shift = 0; shift < egpio->chip.ngpio;
shift += (1<<ei->reg_shift)) {
int reg = egpio->reg_start + egpio_pos(ei, shift);
if (!((egpio->is_out >> shift) & ei->reg_mask))
continue;
pr_debug("EGPIO: setting %x to %x, was %x\n", reg,
(egpio->cached_values >> shift) & ei->reg_mask,
egpio_readw(ei, reg));
egpio_writew((egpio->cached_values >> shift)
& ei->reg_mask, ei, reg);
}
}
}
/*
* Setup
*/
static int __init egpio_probe(struct platform_device *pdev)
{
struct htc_egpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct resource *res;
struct egpio_info *ei;
struct gpio_chip *chip;
unsigned int irq, irq_end;
int i;
/* Initialize ei data structure. */
ei = devm_kzalloc(&pdev->dev, sizeof(*ei), GFP_KERNEL);
if (!ei)
return -ENOMEM;
spin_lock_init(&ei->lock);
/* Find chained irq */
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (res)
ei->chained_irq = res->start;
/* Map egpio chip into virtual address space. */
ei->base_addr = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(ei->base_addr))
return PTR_ERR(ei->base_addr);
if ((pdata->bus_width != 16) && (pdata->bus_width != 32))
return -EINVAL;
ei->bus_shift = fls(pdata->bus_width - 1) - 3;
pr_debug("bus_shift = %d\n", ei->bus_shift);
if ((pdata->reg_width != 8) && (pdata->reg_width != 16))
return -EINVAL;
ei->reg_shift = fls(pdata->reg_width - 1);
pr_debug("reg_shift = %d\n", ei->reg_shift);
ei->reg_mask = (1 << pdata->reg_width) - 1;
platform_set_drvdata(pdev, ei);
ei->nchips = pdata->num_chips;
ei->chip = devm_kcalloc(&pdev->dev,
ei->nchips, sizeof(struct egpio_chip),
GFP_KERNEL);
if (!ei->chip)
return -ENOMEM;
for (i = 0; i < ei->nchips; i++) {
ei->chip[i].reg_start = pdata->chip[i].reg_start;
ei->chip[i].cached_values = pdata->chip[i].initial_values;
ei->chip[i].is_out = pdata->chip[i].direction;
ei->chip[i].dev = &(pdev->dev);
chip = &(ei->chip[i].chip);
chip->label = devm_kasprintf(&pdev->dev, GFP_KERNEL,
"htc-egpio-%d",
i);
if (!chip->label)
return -ENOMEM;
chip->parent = &pdev->dev;
chip->owner = THIS_MODULE;
chip->get = egpio_get;
chip->set = egpio_set;
chip->direction_input = egpio_direction_input;
chip->direction_output = egpio_direction_output;
chip->get_direction = egpio_get_direction;
chip->base = pdata->chip[i].gpio_base;
chip->ngpio = pdata->chip[i].num_gpios;
gpiochip_add_data(chip, &ei->chip[i]);
}
/* Set initial pin values */
egpio_write_cache(ei);
ei->irq_start = pdata->irq_base;
ei->nirqs = pdata->num_irqs;
ei->ack_register = pdata->ack_register;
if (ei->chained_irq) {
/* Setup irq handlers */
ei->ack_write = 0xFFFF;
if (pdata->invert_acks)
ei->ack_write = 0;
irq_end = ei->irq_start + ei->nirqs;
for (irq = ei->irq_start; irq < irq_end; irq++) {
irq_set_chip_and_handler(irq, &egpio_muxed_chip,
handle_simple_irq);
irq_set_chip_data(irq, ei);
irq_clear_status_flags(irq, IRQ_NOREQUEST | IRQ_NOPROBE);
}
irq_set_irq_type(ei->chained_irq, IRQ_TYPE_EDGE_RISING);
irq_set_chained_handler_and_data(ei->chained_irq,
egpio_handler, ei);
ack_irqs(ei);
device_init_wakeup(&pdev->dev, 1);
}
return 0;
}
#ifdef CONFIG_PM
static int egpio_suspend(struct platform_device *pdev, pm_message_t state)
{
struct egpio_info *ei = platform_get_drvdata(pdev);
if (ei->chained_irq && device_may_wakeup(&pdev->dev))
enable_irq_wake(ei->chained_irq);
return 0;
}
static int egpio_resume(struct platform_device *pdev)
{
struct egpio_info *ei = platform_get_drvdata(pdev);
if (ei->chained_irq && device_may_wakeup(&pdev->dev))
disable_irq_wake(ei->chained_irq);
/* Update registers from the cache, in case
the CPLD was powered off during suspend */
egpio_write_cache(ei);
return 0;
}
#else
#define egpio_suspend NULL
#define egpio_resume NULL
#endif
static struct platform_driver egpio_driver = {
.driver = {
.name = "htc-egpio",
.suppress_bind_attrs = true,
},
.suspend = egpio_suspend,
.resume = egpio_resume,
};
static int __init egpio_init(void)
{
return platform_driver_probe(&egpio_driver, egpio_probe);
}
/* start early for dependencies */
subsys_initcall(egpio_init);
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