gpio: add IRQ chip helpers in gpiolib (14250520) · Commits · 戴 / test

drivers/gpio/Kconfig

+3 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,9 @@ config GPIO_ACPI
		def_bool y
		depends on ACPI

		config GPIOLIB_IRQCHIP
		bool

		config DEBUG_GPIO
		bool "Debug GPIO calls"
		depends on DEBUG_KERNEL

drivers/gpio/gpiolib.c

+188 −0

Original line number	Diff line number	Diff line
		@@ -1254,6 +1254,9 @@ fail:
		}
		EXPORT_SYMBOL_GPL(gpiochip_add);

		/* Forward-declaration */
		static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);

		/**
		* gpiochip_remove() - unregister a gpio_chip
		* @chip: the chip to unregister
		@@ -1270,6 +1273,7 @@ int gpiochip_remove(struct gpio_chip *chip)

		spin_lock_irqsave(&gpio_lock, flags);

		gpiochip_irqchip_remove(chip);
		gpiochip_remove_pin_ranges(chip);
		of_gpiochip_remove(chip);

		@@ -1339,6 +1343,190 @@ static struct gpio_chip find_chip_by_name(const char name)
		return gpiochip_find((void *)name, gpiochip_match_name);
		}

		#ifdef CONFIG_GPIOLIB_IRQCHIP

		/*
		* The following is irqchip helper code for gpiochips.
		*/

		/**
		* gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip
		* @gpiochip: the gpiochip to add the irqchip to
		* @irqchip: the irqchip to add to the gpiochip
		* @parent_irq: the irq number corresponding to the parent IRQ for this
		* chained irqchip
		* @parent_handler: the parent interrupt handler for the accumulated IRQ
		* coming out of the gpiochip
		*/
		void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
		struct irq_chip *irqchip,
		int parent_irq,
		irq_flow_handler_t parent_handler)
		{
		irq_set_chained_handler(parent_irq, parent_handler);
		/*
		* The parent irqchip is already using the chip_data for this
		* irqchip, so our callbacks simply use the handler_data.
		*/
		irq_set_handler_data(parent_irq, gpiochip);
		}
		EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);

		/**
		* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
		* @d: the irqdomain used by this irqchip
		* @irq: the global irq number used by this GPIO irqchip irq
		* @hwirq: the local IRQ/GPIO line offset on this gpiochip
		*
		* This function will set up the mapping for a certain IRQ line on a
		* gpiochip by assigning the gpiochip as chip data, and using the irqchip
		* stored inside the gpiochip.
		*/
		static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
		irq_hw_number_t hwirq)
		{
		struct gpio_chip *chip = d->host_data;

		irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
		irq_set_chip_data(irq, chip);
		#ifdef CONFIG_ARM
		set_irq_flags(irq, IRQF_VALID);
		#else
		irq_set_noprobe(irq);
		#endif
		irq_set_irq_type(irq, chip->irq_default_type);

		return 0;
		}

		static const struct irq_domain_ops gpiochip_domain_ops = {
		.map = gpiochip_irq_map,
		/* Virtually all GPIO irqchips are twocell:ed */
		.xlate = irq_domain_xlate_twocell,
		};

		static int gpiochip_irq_reqres(struct irq_data *d)
		{
		struct gpio_chip *chip = irq_data_get_irq_chip_data(d);

		if (gpio_lock_as_irq(chip, d->hwirq)) {
		chip_err(chip,
		"unable to lock HW IRQ %lu for IRQ\n",
		d->hwirq);
		return -EINVAL;
		}
		return 0;
		}

		static void gpiochip_irq_relres(struct irq_data *d)
		{
		struct gpio_chip *chip = irq_data_get_irq_chip_data(d);

		gpio_unlock_as_irq(chip, d->hwirq);
		}

		static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
		{
		return irq_find_mapping(chip->irqdomain, offset);
		}

		/**
		* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
		* @gpiochip: the gpiochip to remove the irqchip from
		*
		* This is called only from gpiochip_remove()
		*/
		static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
		{
		if (gpiochip->irqdomain)
		irq_domain_remove(gpiochip->irqdomain);

		if (gpiochip->irqchip) {
		gpiochip->irqchip->irq_request_resources = NULL;
		gpiochip->irqchip->irq_release_resources = NULL;
		gpiochip->irqchip = NULL;
		}
		}

		/**
		* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
		* @gpiochip: the gpiochip to add the irqchip to
		* @irqchip: the irqchip to add to the gpiochip
		* @first_irq: if not dynamically assigned, the base (first) IRQ to
		* allocate gpiochip irqs from
		* @handler: the irq handler to use (often a predefined irq core function)
		* @type: the default type for IRQs on this irqchip
		*
		* This function closely associates a certain irqchip with a certain
		* gpiochip, providing an irq domain to translate the local IRQs to
		* global irqs in the gpiolib core, and making sure that the gpiochip
		* is passed as chip data to all related functions. Driver callbacks
		* need to use container_of() to get their local state containers back
		* from the gpiochip passed as chip data. An irqdomain will be stored
		* in the gpiochip that shall be used by the driver to handle IRQ number
		* translation. The gpiochip will need to be initialized and registered
		* before calling this function.
		*
		* This function will handle two cell:ed simple IRQs. Everything else
		* need to be open coded.
		*/
		int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
		struct irq_chip *irqchip,
		unsigned int first_irq,
		irq_flow_handler_t handler,
		unsigned int type)
		{
		struct device_node *of_node;
		unsigned int offset;

		if (!gpiochip \|\| !irqchip)
		return -EINVAL;

		if (!gpiochip->dev) {
		pr_err("missing gpiochip .dev parent pointer\n");
		return -EINVAL;
		}
		of_node = gpiochip->dev->of_node;
		#ifdef CONFIG_OF_GPIO
		/*
		* If the gpiochip has an assigned OF node this takes precendence
		* FIXME: get rid of this and use gpiochip->dev->of_node everywhere
		*/
		if (gpiochip->of_node)
		of_node = gpiochip->of_node;
		#endif
		gpiochip->irqchip = irqchip;
		gpiochip->irq_handler = handler;
		gpiochip->irq_default_type = type;
		gpiochip->to_irq = gpiochip_to_irq;
		gpiochip->irqdomain = irq_domain_add_simple(of_node,
		gpiochip->ngpio, first_irq,
		&gpiochip_domain_ops, gpiochip);
		if (!gpiochip->irqdomain) {
		gpiochip->irqchip = NULL;
		return -EINVAL;
		}
		irqchip->irq_request_resources = gpiochip_irq_reqres;
		irqchip->irq_release_resources = gpiochip_irq_relres;

		/*
		* Prepare the mapping since the irqchip shall be orthogonal to
		* any gpiochip calls. If the first_irq was zero, this is
		* necessary to allocate descriptors for all IRQs.
		*/
		for (offset = 0; offset < gpiochip->ngpio; offset++)
		irq_create_mapping(gpiochip->irqdomain, offset);

		return 0;
		}
		EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);

		#else /* CONFIG_GPIOLIB_IRQCHIP */

		static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}

		#endif /* CONFIG_GPIOLIB_IRQCHIP */

		#ifdef CONFIG_PINCTRL

		/**

include/linux/gpio/driver.h

+29 −0

Original line number	Diff line number	Diff line
		@@ -3,6 +3,9 @@

		#include <linux/types.h>
		#include <linux/module.h>
		#include <linux/irq.h>
		#include <linux/irqchip/chained_irq.h>
		#include <linux/irqdomain.h>

		struct device;
		struct gpio_desc;
		@@ -97,6 +100,17 @@ struct gpio_chip {
		bool can_sleep;
		bool exported;

		#ifdef CONFIG_GPIOLIB_IRQCHIP
		/*
		* With CONFIG_GPIO_IRQCHIP we get an irqchip inside the gpiolib
		* to handle IRQs for most practical cases.
		*/
		struct irq_chip *irqchip;
		struct irq_domain *irqdomain;
		irq_flow_handler_t irq_handler;
		unsigned int irq_default_type;
		#endif

		#if defined(CONFIG_OF_GPIO)
		/*
		* If CONFIG_OF is enabled, then all GPIO controllers described in the
		@@ -190,6 +204,21 @@ struct gpiod_lookup_table {

		void gpiod_add_lookup_table(struct gpiod_lookup_table *table);

		#ifdef CONFIG_GPIOLIB_IRQCHIP

		void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
		struct irq_chip *irqchip,
		int parent_irq,
		irq_flow_handler_t parent_handler);

		int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
		struct irq_chip *irqchip,
		unsigned int first_irq,
		irq_flow_handler_t handler,
		unsigned int type);

		#endif /* CONFIG_GPIO_IRQCHIP */

		#else /* CONFIG_GPIOLIB */

		static inline struct gpio_chip gpiod_to_chip(const struct gpio_desc desc)

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