Commit ba8c90c6 authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Bartosz Golaszewski
Browse files

gpio: pca953x: Override IRQ for one of the expanders on Galileo Gen 2 



ACPI table on Intel Galileo Gen 2 has wrong pin number for IRQ resource
of one of the I²C GPIO expanders. Since we know what that number is and
luckily have GPIO bases fixed for SoC's controllers, we may use a simple
DMI quirk to match the platform and retrieve GpioInt() pin on it for
the expander in question.

Mika suggested the way to avoid a quirk in the GPIO ACPI library and
here is the second, almost rewritten version of it.

Fixes: f32517bf ("gpio: pca953x: support ACPI devices found on Galileo Gen2")
Depends-on: 25e3ef89 ("gpio: acpi: Split out acpi_gpio_get_irq_resource() helper")
Suggested-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: default avatarBartosz Golaszewski <bgolaszewski@baylibre.com>
parent 064c73af

drivers/gpio/gpio-pca953x.c

+79 −0
Original line number Diff line number Diff line
@@ -107,6 +107,79 @@ static const struct i2c_device_id pca953x_id[] = { 
};

MODULE_DEVICE_TABLE(i2c, pca953x_id);



#ifdef CONFIG_GPIO_PCA953X_IRQ



#include <linux/dmi.h>

#include <linux/gpio.h>

#include <linux/list.h>



static const struct dmi_system_id pca953x_dmi_acpi_irq_info[] = {

	{

		/*

		 * On Intel Galileo Gen 2 board the IRQ pin of one of

		 * the I²C GPIO expanders, which has GpioInt() resource,

		 * is provided as an absolute number instead of being

		 * relative. Since first controller (gpio-sch.c) and

		 * second (gpio-dwapb.c) are at the fixed bases, we may

		 * safely refer to the number in the global space to get

		 * an IRQ out of it.

		 */

		.matches = {

			DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"),

		},

	},

	{}

};



#ifdef CONFIG_ACPI

static int pca953x_acpi_get_pin(struct acpi_resource *ares, void *data)

{

	struct acpi_resource_gpio *agpio;

	int *pin = data;



	if (acpi_gpio_get_irq_resource(ares, &agpio))

		*pin = agpio->pin_table[0];

	return 1;

}



static int pca953x_acpi_find_pin(struct device *dev)

{

	struct acpi_device *adev = ACPI_COMPANION(dev);

	int pin = -ENOENT, ret;

	LIST_HEAD(r);



	ret = acpi_dev_get_resources(adev, &r, pca953x_acpi_get_pin, &pin);

	acpi_dev_free_resource_list(&r);

	if (ret < 0)

		return ret;



	return pin;

}

#else

static inline int pca953x_acpi_find_pin(struct device *dev) { return -ENXIO; }

#endif



static int pca953x_acpi_get_irq(struct device *dev)

{

	int pin, ret;



	pin = pca953x_acpi_find_pin(dev);

	if (pin < 0)

		return pin;



	dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin);



	if (!gpio_is_valid(pin))

		return -EINVAL;



	ret = gpio_request(pin, "pca953x interrupt");

	if (ret)

		return ret;



	return gpio_to_irq(pin);

}

#endif



static const struct acpi_device_id pca953x_acpi_ids[] = {

	{ "INT3491", 16 | PCA953X_TYPE | PCA_LATCH_INT, },

	{ }
@@ -754,6 +827,12 @@ static int pca953x_irq_setup(struct pca953x_chip *chip, int irq_base) 
	DECLARE_BITMAP(irq_stat, MAX_LINE);

	int ret;



	if (dmi_first_match(pca953x_dmi_acpi_irq_info)) {

		ret = pca953x_acpi_get_irq(&client->dev);

		if (ret > 0)

			client->irq = ret;

	}



	if (!client->irq)

		return 0;

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