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gpio: pcf857x: enable gpio_to_irq() support 

pcf857x chip has some pins, but interrupt pin is only 1 pin.
And gpiolib requests 1 interrupt per 1 gpio pin.

Thus, this patch added demuxed irq to pcf857x driver,
and enabled gpio_to_irq().

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Kuninori Morimoto 2012-06-14 19:40:41 -07:00 committed by Linus Walleij
parent 7cb6580c0b
commit 6e20a0a429
2 changed files with 125 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

122
drivers/gpio/gpio-pcf857x.c
View File

@ -23,7 +23,12 @@
#include <linux/gpio.h>
#include <linux/i2c.h>
#include <linux/i2c/pcf857x.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
static const struct i2c_device_id pcf857x_id[] = {
@ -60,7 +65,12 @@ struct pcf857x {
struct gpio_chip chip;
struct i2c_client *client;
struct mutex lock; /* protect 'out' */
struct work_struct work; /* irq demux work */
struct irq_domain *irq_domain; /* for irq demux */
spinlock_t slock; /* protect irq demux */
unsigned out; /* software latch */
unsigned status; /* current status */
int irq; /* real irq number */
int (*write)(struct i2c_client *client, unsigned data);
int (*read)(struct i2c_client *client);
@ -150,6 +160,100 @@ static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value)
/*-------------------------------------------------------------------------*/
static int pcf857x_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct pcf857x *gpio = container_of(chip, struct pcf857x, chip);
return irq_create_mapping(gpio->irq_domain, offset);
}
static void pcf857x_irq_demux_work(struct work_struct *work)
{
struct pcf857x *gpio = container_of(work,
struct pcf857x,
work);
unsigned long change, i, status, flags;
status = gpio->read(gpio->client);
spin_lock_irqsave(&gpio->slock, flags);
change = gpio->status ^ status;
for_each_set_bit(i, &change, gpio->chip.ngpio)
generic_handle_irq(irq_find_mapping(gpio->irq_domain, i));
gpio->status = status;
spin_unlock_irqrestore(&gpio->slock, flags);
}
static irqreturn_t pcf857x_irq_demux(int irq, void *data)
{
struct pcf857x *gpio = data;
/*
* pcf857x can't read/write data here,
* since i2c data access might go to sleep.
*/
schedule_work(&gpio->work);
return IRQ_HANDLED;
}
static int pcf857x_irq_domain_map(struct irq_domain *domain, unsigned int virq,
irq_hw_number_t hw)
{
irq_set_chip_and_handler(virq,
&dummy_irq_chip,
handle_level_irq);
return 0;
}
static struct irq_domain_ops pcf857x_irq_domain_ops = {
.map = pcf857x_irq_domain_map,
};
static void pcf857x_irq_domain_cleanup(struct pcf857x *gpio)
{
if (gpio->irq_domain)
irq_domain_remove(gpio->irq_domain);
if (gpio->irq)
free_irq(gpio->irq, gpio);
}
static int pcf857x_irq_domain_init(struct pcf857x *gpio,
struct pcf857x_platform_data *pdata,
struct device *dev)
{
int status;
gpio->irq_domain = irq_domain_add_linear(dev->of_node,
gpio->chip.ngpio,
&pcf857x_irq_domain_ops,
NULL);
if (!gpio->irq_domain)
goto fail;
/* enable real irq */
status = request_irq(pdata->irq, pcf857x_irq_demux, 0,
dev_name(dev), gpio);
if (status)
goto fail;
/* enable gpio_to_irq() */
INIT_WORK(&gpio->work, pcf857x_irq_demux_work);
gpio->chip.to_irq = pcf857x_to_irq;
gpio->irq = pdata->irq;
return 0;
fail:
pcf857x_irq_domain_cleanup(gpio);
return -EINVAL;
}
/*-------------------------------------------------------------------------*/
static int pcf857x_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@ -168,6 +272,7 @@ static int pcf857x_probe(struct i2c_client *client,
return -ENOMEM;
mutex_init(&gpio->lock);
spin_lock_init(&gpio->slock);
gpio->chip.base = pdata ? pdata->gpio_base : -1;
gpio->chip.can_sleep = 1;
@ -179,6 +284,15 @@ static int pcf857x_probe(struct i2c_client *client,
gpio->chip.direction_output = pcf857x_output;
gpio->chip.ngpio = id->driver_data;
/* enable gpio_to_irq() if platform has settings */
if (pdata->irq) {
status = pcf857x_irq_domain_init(gpio, pdata, &client->dev);
if (status < 0) {
dev_err(&client->dev, "irq_domain init failed\n");
goto fail;
}
}
/* NOTE: the OnSemi jlc1562b is also largely compatible with
* these parts, notably for output. It has a low-resolution
* DAC instead of pin change IRQs; and its inputs can be the
@ -248,6 +362,7 @@ static int pcf857x_probe(struct i2c_client *client,
* all-ones reset state. Otherwise it flags pins to be driven low.
*/
gpio->out = pdata ? ~pdata->n_latch : ~0;
gpio->status = gpio->out;
status = gpiochip_add(&gpio->chip);
if (status < 0)
@ -278,6 +393,10 @@ static int pcf857x_probe(struct i2c_client *client,
fail:
dev_dbg(&client->dev, "probe error %d for '%s'\n",
status, client->name);
if (pdata->irq)
pcf857x_irq_domain_cleanup(gpio);
kfree(gpio);
return status;
}
@ -299,6 +418,9 @@ static int pcf857x_remove(struct i2c_client *client)
}
}
if (pdata->irq)
pcf857x_irq_domain_cleanup(gpio);
status = gpiochip_remove(&gpio->chip);
if (status == 0)
kfree(gpio);

3
include/linux/i2c/pcf857x.h
View File

@ -10,6 +10,7 @@
* @setup: optional callback issued once the GPIOs are valid
* @teardown: optional callback issued before the GPIOs are invalidated
* @context: optional parameter passed to setup() and teardown()
* @irq: optional interrupt number
*
* In addition to the I2C_BOARD_INFO() state appropriate to each chip,
* the i2c_board_info used with the pcf875x driver must provide its
@ -39,6 +40,8 @@ struct pcf857x_platform_data {
int gpio, unsigned ngpio,
void *context);
void *context;
int irq;
};
#endif /* __LINUX_PCF857X_H */