gpio: pcf857x: enable gpio_to_irq() support (6e20a0a4) · Commits · 戴 / test

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 */

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