Commit e2ff7408 authored by Bartosz Golaszewski's avatar Bartosz Golaszewski Committed by Linus Walleij
Browse files

gpio: mockup: add a dummy irqchip 



Setup a dummy irqchip that will allow us to inject line events for
testing purposes.

Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 8a68ea00

drivers/gpio/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -298,6 +298,8 @@ config GPIO_MOCKUP 
	tristate "GPIO Testing Driver"

	depends on GPIOLIB && SYSFS

	select GPIO_SYSFS

	select GPIOLIB_IRQCHIP

	select IRQ_WORK

	help

	  This enables GPIO Testing driver, which provides a way to test GPIO

	  subsystem through sysfs(or char device) and debugfs. GPIO_SYSFS

drivers/gpio/gpio-mockup.c

+79 −0
Original line number Diff line number Diff line
@@ -16,6 +16,9 @@ 
#include <linux/gpio/driver.h>

#include <linux/platform_device.h>

#include <linux/slab.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/irq_work.h>



#define GPIO_MOCKUP_NAME	"gpio-mockup"

#define	GPIO_MOCKUP_MAX_GC	10
@@ -35,9 +38,15 @@ struct gpio_mockup_line_status { 
	bool value;

};



struct gpio_mockup_irq_context {

	struct irq_work work;

	int irq;

};



struct gpio_mockup_chip {

	struct gpio_chip gc;

	struct gpio_mockup_line_status *lines;

	struct gpio_mockup_irq_context irq_ctx;

};



static int gpio_mockup_ranges[GPIO_MOCKUP_MAX_GC << 1];
@@ -115,6 +124,57 @@ static int gpio_mockup_name_lines(struct device *dev, 
	return 0;

}



static int gpio_mockup_to_irq(struct gpio_chip *chip, unsigned int offset)

{

	return chip->irq_base + offset;

}



/*

 * While we should generally support irqmask and irqunmask, this driver is

 * for testing purposes only so we don't care.

 */

static void gpio_mockup_irqmask(struct irq_data *d) { }

static void gpio_mockup_irqunmask(struct irq_data *d) { }



static struct irq_chip gpio_mockup_irqchip = {

	.name		= GPIO_MOCKUP_NAME,

	.irq_mask	= gpio_mockup_irqmask,

	.irq_unmask	= gpio_mockup_irqunmask,

};



static void gpio_mockup_handle_irq(struct irq_work *work)

{

	struct gpio_mockup_irq_context *irq_ctx;



	irq_ctx = container_of(work, struct gpio_mockup_irq_context, work);

	handle_simple_irq(irq_to_desc(irq_ctx->irq));

}



static int gpio_mockup_irqchip_setup(struct device *dev,

				     struct gpio_mockup_chip *chip)

{

	struct gpio_chip *gc = &chip->gc;

	int irq_base, i;



	irq_base = irq_alloc_descs(-1, 0, gc->ngpio, 0);

	if (irq_base < 0)

		return irq_base;



	gc->irq_base = irq_base;

	gc->irqchip = &gpio_mockup_irqchip;



	for (i = 0; i < gc->ngpio; i++) {

		irq_set_chip(irq_base + i, gc->irqchip);

		irq_set_handler(irq_base + i, &handle_simple_irq);

		irq_modify_status(irq_base + i,

				  IRQ_NOREQUEST | IRQ_NOAUTOEN, IRQ_NOPROBE);

	}



	init_irq_work(&chip->irq_ctx.work, gpio_mockup_handle_irq);



	return 0;

}



static int gpio_mockup_add(struct device *dev,

			   struct gpio_mockup_chip *chip,

			   const char *name, int base, int ngpio)
@@ -132,6 +192,7 @@ static int gpio_mockup_add(struct device *dev, 
	gc->direction_output = gpio_mockup_dirout;

	gc->direction_input = gpio_mockup_dirin;

	gc->get_direction = gpio_mockup_get_direction;

	gc->to_irq = gpio_mockup_to_irq;



	chip->lines = devm_kzalloc(dev, sizeof(*chip->lines) * gc->ngpio,

				   GFP_KERNEL);
@@ -144,6 +205,10 @@ static int gpio_mockup_add(struct device *dev, 
			return ret;

	}



	ret = gpio_mockup_irqchip_setup(dev, chip);

	if (ret)

		return ret;



	return devm_gpiochip_add_data(dev, &chip->gc, chip);

}
@@ -200,11 +265,25 @@ static int gpio_mockup_probe(struct platform_device *pdev) 
	return 0;

}



static int gpio_mockup_remove(struct platform_device *pdev)

{

	struct gpio_mockup_chip *chips;

	int i;



	chips = platform_get_drvdata(pdev);



	for (i = 0; i < gpio_mockup_params_nr >> 1; i++)

		irq_free_descs(chips[i].gc.irq_base, chips[i].gc.ngpio);



	return 0;

}



static struct platform_driver gpio_mockup_driver = {

	.driver = {

		.name = GPIO_MOCKUP_NAME,

	},

	.probe = gpio_mockup_probe,

	.remove = gpio_mockup_remove,

};



static struct platform_device *pdev;