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Commit e0d89728 authored by Thierry Reding's avatar Thierry Reding Committed by Linus Walleij
Browse files

gpio: Implement tighter IRQ chip integration 



Currently GPIO drivers are required to add the GPIO chip and its
corresponding IRQ chip separately, which can result in a lot of
boilerplate. Use the newly introduced struct gpio_irq_chip, embedded in
struct gpio_chip, that drivers can fill in if they want the GPIO core
to automatically register the IRQ chip associated with a GPIO chip.

Signed-off-by: default avatarThierry Reding <treding@nvidia.com>
Acked-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent ca9df053

drivers/gpio/gpiolib.c

+107 −1
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ static LIST_HEAD(gpio_lookup_list); 
LIST_HEAD(gpio_devices);



static void gpiochip_free_hogs(struct gpio_chip *chip);

static int gpiochip_add_irqchip(struct gpio_chip *gpiochip);

static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);

static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);

static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
@@ -1266,6 +1267,10 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data) 
	if (status)

		goto err_remove_from_list;



	status = gpiochip_add_irqchip(chip);

	if (status)

		goto err_remove_chip;



	status = of_gpiochip_add(chip);

	if (status)

		goto err_remove_chip;
@@ -1637,6 +1642,7 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, 
			    irq_hw_number_t hwirq)

{

	struct gpio_chip *chip = d->host_data;

	int err = 0;



	if (!gpiochip_irqchip_irq_valid(chip, hwirq))

		return -ENXIO;
@@ -1653,6 +1659,14 @@ static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, 
		irq_set_nested_thread(irq, 1);

	irq_set_noprobe(irq);



	if (chip->irq.num_parents == 1)

		err = irq_set_parent(irq, chip->irq.parents[0]);

	else if (chip->irq.map)

		err = irq_set_parent(irq, chip->irq.map[hwirq]);



	if (err < 0)

		return err;



	/*

	 * No set-up of the hardware will happen if IRQ_TYPE_NONE

	 * is passed as default type.
@@ -1709,9 +1723,96 @@ static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) 
{

	if (!gpiochip_irqchip_irq_valid(chip, offset))

		return -ENXIO;



	return irq_create_mapping(chip->irq.domain, offset);

}



/**

 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip

 * @gpiochip: the GPIO chip to add the IRQ chip to

 */

static int gpiochip_add_irqchip(struct gpio_chip *gpiochip)

{

	struct irq_chip *irqchip = gpiochip->irq.chip;

	const struct irq_domain_ops *ops;

	struct device_node *np;

	unsigned int type;

	unsigned int i;



	if (!irqchip)

		return 0;



	if (gpiochip->irq.parent_handler && gpiochip->can_sleep) {

		chip_err(gpiochip, "you cannot have chained interrupts on a "

			 "chip that may sleep\n");

		return -EINVAL;

	}



	np = gpiochip->gpiodev->dev.of_node;

	type = gpiochip->irq.default_type;



	/*

	 * Specifying a default trigger is a terrible idea if DT or ACPI is

	 * used to configure the interrupts, as you may end up with

	 * conflicting triggers. Tell the user, and reset to NONE.

	 */

	if (WARN(np && type != IRQ_TYPE_NONE,

		 "%s: Ignoring %u default trigger\n", np->full_name, type))

		type = IRQ_TYPE_NONE;



	if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) {

		acpi_handle_warn(ACPI_HANDLE(gpiochip->parent),

				 "Ignoring %u default trigger\n", type);

		type = IRQ_TYPE_NONE;

	}



	gpiochip->to_irq = gpiochip_to_irq;

	gpiochip->irq.default_type = type;



	if (gpiochip->irq.domain_ops)

		ops = gpiochip->irq.domain_ops;

	else

		ops = &gpiochip_domain_ops;



	gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio,

						     0, ops, gpiochip);

	if (!gpiochip->irq.domain)

		return -EINVAL;



	/*

	 * It is possible for a driver to override this, but only if the

	 * alternative functions are both implemented.

	 */

	if (!irqchip->irq_request_resources &&

	    !irqchip->irq_release_resources) {

		irqchip->irq_request_resources = gpiochip_irq_reqres;

		irqchip->irq_release_resources = gpiochip_irq_relres;

	}



	if (gpiochip->irq.parent_handler) {

		void *data = gpiochip->irq.parent_handler_data ?: gpiochip;



		for (i = 0; i < gpiochip->irq.num_parents; i++) {

			/*

			 * The parent IRQ chip is already using the chip_data

			 * for this IRQ chip, so our callbacks simply use the

			 * handler_data.

			 */

			irq_set_chained_handler_and_data(gpiochip->irq.parents[i],

							 gpiochip->irq.parent_handler,

							 data);

		}



		gpiochip->irq.nested = false;

	} else {

		gpiochip->irq.nested = true;

	}



	acpi_gpiochip_request_interrupts(gpiochip);



	return 0;

}



/**

 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip

 * @gpiochip: the gpiochip to remove the irqchip from
@@ -1724,7 +1825,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) 


	acpi_gpiochip_free_interrupts(gpiochip);



	if (gpiochip->irq.num_parents > 0) {

	if (gpiochip->irq.chip && gpiochip->irq.parent_handler) {

		struct gpio_irq_chip *irq = &gpiochip->irq;

		unsigned int i;
@@ -1857,6 +1958,11 @@ EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key); 


#else /* CONFIG_GPIOLIB_IRQCHIP */



static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip)

{

	return 0;

}



static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}

static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)

{

include/linux/gpio/driver.h

+7 −0
Original line number Diff line number Diff line
@@ -100,6 +100,13 @@ struct gpio_irq_chip { 
	 */

	unsigned int *parents;



	/**

	 * @map:

	 *

	 * A list of interrupt parents for each line of a GPIO chip.

	 */

	unsigned int *map;



	/**

	 * @nested:

	 *