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Commit 6e20a0a4 authored by Kuninori Morimoto's avatar Kuninori Morimoto Committed by Linus Walleij
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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: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 7cb6580c

drivers/gpio/gpio-pcf857x.c

+122 −0
Original line number Diff line number Diff line
@@ -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);

include/linux/i2c/pcf857x.h

+3 −0
Original line number Diff line number Diff line
@@ -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 */