linux/drivers/gpio/tc35892-gpio.c

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/*
* Copyright (C) ST-Ericsson SA 2010
*
* License Terms: GNU General Public License, version 2
* Author: Hanumath Prasad <hanumath.prasad@stericsson.com> for ST-Ericsson
* Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/mfd/tc35892.h>
/*
* These registers are modified under the irq bus lock and cached to avoid
* unnecessary writes in bus_sync_unlock.
*/
enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
#define CACHE_NR_REGS 4
#define CACHE_NR_BANKS 3
struct tc35892_gpio {
struct gpio_chip chip;
struct tc35892 *tc35892;
struct device *dev;
struct mutex irq_lock;
int irq_base;
/* Caches of interrupt control registers for bus_lock */
u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
};
static inline struct tc35892_gpio *to_tc35892_gpio(struct gpio_chip *chip)
{
return container_of(chip, struct tc35892_gpio, chip);
}
static int tc35892_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
u8 mask = 1 << (offset % 8);
int ret;
ret = tc35892_reg_read(tc35892, reg);
if (ret < 0)
return ret;
return ret & mask;
}
static void tc35892_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
u8 reg = TC35892_GPIODATA0 + (offset / 8) * 2;
unsigned pos = offset % 8;
u8 data[] = {!!val << pos, 1 << pos};
tc35892_block_write(tc35892, reg, ARRAY_SIZE(data), data);
}
static int tc35892_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int val)
{
struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
u8 reg = TC35892_GPIODIR0 + offset / 8;
unsigned pos = offset % 8;
tc35892_gpio_set(chip, offset, val);
return tc35892_set_bits(tc35892, reg, 1 << pos, 1 << pos);
}
static int tc35892_gpio_direction_input(struct gpio_chip *chip,
unsigned offset)
{
struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
u8 reg = TC35892_GPIODIR0 + offset / 8;
unsigned pos = offset % 8;
return tc35892_set_bits(tc35892, reg, 1 << pos, 0);
}
static int tc35892_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct tc35892_gpio *tc35892_gpio = to_tc35892_gpio(chip);
return tc35892_gpio->irq_base + offset;
}
static struct gpio_chip template_chip = {
.label = "tc35892",
.owner = THIS_MODULE,
.direction_input = tc35892_gpio_direction_input,
.get = tc35892_gpio_get,
.direction_output = tc35892_gpio_direction_output,
.set = tc35892_gpio_set,
.to_irq = tc35892_gpio_to_irq,
.can_sleep = 1,
};
static int tc35892_gpio_irq_set_type(unsigned int irq, unsigned int type)
{
struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
int offset = irq - tc35892_gpio->irq_base;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
if (type == IRQ_TYPE_EDGE_BOTH) {
tc35892_gpio->regs[REG_IBE][regoffset] |= mask;
return 0;
}
tc35892_gpio->regs[REG_IBE][regoffset] &= ~mask;
if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
tc35892_gpio->regs[REG_IS][regoffset] |= mask;
else
tc35892_gpio->regs[REG_IS][regoffset] &= ~mask;
if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH)
tc35892_gpio->regs[REG_IEV][regoffset] |= mask;
else
tc35892_gpio->regs[REG_IEV][regoffset] &= ~mask;
return 0;
}
static void tc35892_gpio_irq_lock(unsigned int irq)
{
struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
mutex_lock(&tc35892_gpio->irq_lock);
}
static void tc35892_gpio_irq_sync_unlock(unsigned int irq)
{
struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
static const u8 regmap[] = {
[REG_IBE] = TC35892_GPIOIBE0,
[REG_IEV] = TC35892_GPIOIEV0,
[REG_IS] = TC35892_GPIOIS0,
[REG_IE] = TC35892_GPIOIE0,
};
int i, j;
for (i = 0; i < CACHE_NR_REGS; i++) {
for (j = 0; j < CACHE_NR_BANKS; j++) {
u8 old = tc35892_gpio->oldregs[i][j];
u8 new = tc35892_gpio->regs[i][j];
if (new == old)
continue;
tc35892_gpio->oldregs[i][j] = new;
tc35892_reg_write(tc35892, regmap[i] + j * 8, new);
}
}
mutex_unlock(&tc35892_gpio->irq_lock);
}
static void tc35892_gpio_irq_mask(unsigned int irq)
{
struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
int offset = irq - tc35892_gpio->irq_base;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
tc35892_gpio->regs[REG_IE][regoffset] &= ~mask;
}
static void tc35892_gpio_irq_unmask(unsigned int irq)
{
struct tc35892_gpio *tc35892_gpio = get_irq_chip_data(irq);
int offset = irq - tc35892_gpio->irq_base;
int regoffset = offset / 8;
int mask = 1 << (offset % 8);
tc35892_gpio->regs[REG_IE][regoffset] |= mask;
}
static struct irq_chip tc35892_gpio_irq_chip = {
.name = "tc35892-gpio",
.bus_lock = tc35892_gpio_irq_lock,
.bus_sync_unlock = tc35892_gpio_irq_sync_unlock,
.mask = tc35892_gpio_irq_mask,
.unmask = tc35892_gpio_irq_unmask,
.set_type = tc35892_gpio_irq_set_type,
};
static irqreturn_t tc35892_gpio_irq(int irq, void *dev)
{
struct tc35892_gpio *tc35892_gpio = dev;
struct tc35892 *tc35892 = tc35892_gpio->tc35892;
u8 status[CACHE_NR_BANKS];
int ret;
int i;
ret = tc35892_block_read(tc35892, TC35892_GPIOMIS0,
ARRAY_SIZE(status), status);
if (ret < 0)
return IRQ_NONE;
for (i = 0; i < ARRAY_SIZE(status); i++) {
unsigned int stat = status[i];
if (!stat)
continue;
while (stat) {
int bit = __ffs(stat);
int line = i * 8 + bit;
handle_nested_irq(tc35892_gpio->irq_base + line);
stat &= ~(1 << bit);
}
tc35892_reg_write(tc35892, TC35892_GPIOIC0 + i, status[i]);
}
return IRQ_HANDLED;
}
static int tc35892_gpio_irq_init(struct tc35892_gpio *tc35892_gpio)
{
int base = tc35892_gpio->irq_base;
int irq;
for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
set_irq_chip_data(irq, tc35892_gpio);
set_irq_chip_and_handler(irq, &tc35892_gpio_irq_chip,
handle_simple_irq);
set_irq_nested_thread(irq, 1);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
set_irq_noprobe(irq);
#endif
}
return 0;
}
static void tc35892_gpio_irq_remove(struct tc35892_gpio *tc35892_gpio)
{
int base = tc35892_gpio->irq_base;
int irq;
for (irq = base; irq < base + tc35892_gpio->chip.ngpio; irq++) {
#ifdef CONFIG_ARM
set_irq_flags(irq, 0);
#endif
set_irq_chip_and_handler(irq, NULL, NULL);
set_irq_chip_data(irq, NULL);
}
}
static int __devinit tc35892_gpio_probe(struct platform_device *pdev)
{
struct tc35892 *tc35892 = dev_get_drvdata(pdev->dev.parent);
struct tc35892_gpio_platform_data *pdata;
struct tc35892_gpio *tc35892_gpio;
int ret;
int irq;
pdata = tc35892->pdata->gpio;
if (!pdata)
return -ENODEV;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
tc35892_gpio = kzalloc(sizeof(struct tc35892_gpio), GFP_KERNEL);
if (!tc35892_gpio)
return -ENOMEM;
mutex_init(&tc35892_gpio->irq_lock);
tc35892_gpio->dev = &pdev->dev;
tc35892_gpio->tc35892 = tc35892;
tc35892_gpio->chip = template_chip;
tc35892_gpio->chip.ngpio = tc35892->num_gpio;
tc35892_gpio->chip.dev = &pdev->dev;
tc35892_gpio->chip.base = pdata->gpio_base;
tc35892_gpio->irq_base = tc35892->irq_base + TC35892_INT_GPIO(0);
/* Bring the GPIO module out of reset */
ret = tc35892_set_bits(tc35892, TC35892_RSTCTRL,
TC35892_RSTCTRL_GPIRST, 0);
if (ret < 0)
goto out_free;
ret = tc35892_gpio_irq_init(tc35892_gpio);
if (ret)
goto out_free;
ret = request_threaded_irq(irq, NULL, tc35892_gpio_irq, IRQF_ONESHOT,
"tc35892-gpio", tc35892_gpio);
if (ret) {
dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
goto out_removeirq;
}
ret = gpiochip_add(&tc35892_gpio->chip);
if (ret) {
dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
goto out_freeirq;
}
platform_set_drvdata(pdev, tc35892_gpio);
return 0;
out_freeirq:
free_irq(irq, tc35892_gpio);
out_removeirq:
tc35892_gpio_irq_remove(tc35892_gpio);
out_free:
kfree(tc35892_gpio);
return ret;
}
static int __devexit tc35892_gpio_remove(struct platform_device *pdev)
{
struct tc35892_gpio *tc35892_gpio = platform_get_drvdata(pdev);
int irq = platform_get_irq(pdev, 0);
int ret;
ret = gpiochip_remove(&tc35892_gpio->chip);
if (ret < 0) {
dev_err(tc35892_gpio->dev,
"unable to remove gpiochip: %d\n", ret);
return ret;
}
free_irq(irq, tc35892_gpio);
tc35892_gpio_irq_remove(tc35892_gpio);
platform_set_drvdata(pdev, NULL);
kfree(tc35892_gpio);
return 0;
}
static struct platform_driver tc35892_gpio_driver = {
.driver.name = "tc35892-gpio",
.driver.owner = THIS_MODULE,
.probe = tc35892_gpio_probe,
.remove = __devexit_p(tc35892_gpio_remove),
};
static int __init tc35892_gpio_init(void)
{
return platform_driver_register(&tc35892_gpio_driver);
}
subsys_initcall(tc35892_gpio_init);
static void __exit tc35892_gpio_exit(void)
{
platform_driver_unregister(&tc35892_gpio_driver);
}
module_exit(tc35892_gpio_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TC35892 GPIO driver");
MODULE_AUTHOR("Hanumath Prasad, Rabin Vincent");