Commit 81674bea authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Bartosz Golaszewski
Browse files

gpio: aggregator: Set up a parser of delay line parameters 



The aggregator mode can also handle properties of the platform,
that do not belong to the GPIO controller itself. One of such
a property is a signal delay line. Set up a parser to support it.

Reviewed-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent b466622c

drivers/gpio/gpio-aggregator.c

+70 −2
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/mutex.h>

#include <linux/overflow.h>

#include <linux/platform_device.h>

#include <linux/property.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

#include <linux/string.h>
@@ -422,6 +423,59 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) 
	return gpiod_to_irq(fwd->descs[offset]);

}



/*

 * The GPIO delay provides a way to configure platform specific delays

 * for the GPIO ramp-up or ramp-down delays. This can serve the following

 * purposes:

 *   - Open-drain output using an RC filter

 */

#define FWD_FEATURE_DELAY		BIT(0)



#ifdef CONFIG_OF_GPIO

static int gpiochip_fwd_delay_of_xlate(struct gpio_chip *chip,

				       const struct of_phandle_args *gpiospec,

				       u32 *flags)

{

	struct gpiochip_fwd *fwd = gpiochip_get_data(chip);

	struct gpiochip_fwd_timing *timings;

	u32 line;



	if (gpiospec->args_count != chip->of_gpio_n_cells)

		return -EINVAL;



	line = gpiospec->args[0];

	if (line >= chip->ngpio)

		return -EINVAL;



	timings = &fwd->delay_timings[line];

	timings->ramp_up_us = gpiospec->args[1];

	timings->ramp_down_us = gpiospec->args[2];



	return line;

}



static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,

					 struct gpiochip_fwd *fwd)

{

	fwd->delay_timings = devm_kcalloc(dev, chip->ngpio,

					  sizeof(*fwd->delay_timings),

					  GFP_KERNEL);

	if (!fwd->delay_timings)

		return -ENOMEM;



	chip->of_xlate = gpiochip_fwd_delay_of_xlate;

	chip->of_gpio_n_cells = 3;



	return 0;

}

#else

static int gpiochip_fwd_setup_delay_line(struct device *dev, struct gpio_chip *chip,

					 struct gpiochip_fwd *fwd)

{

	return 0;

}

#endif	/* !CONFIG_OF_GPIO */



/**

 * gpiochip_fwd_create() - Create a new GPIO forwarder

 * @dev: Parent device pointer
@@ -429,6 +483,7 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) 
 * @descs: Array containing the GPIO descriptors to forward to.

 *         This array must contain @ngpios entries, and must not be deallocated

 *         before the forwarder has been destroyed again.

 * @features: Bitwise ORed features as defined with FWD_FEATURE_*.

 *

 * This function creates a new gpiochip, which forwards all GPIO operations to

 * the passed GPIO descriptors.
@@ -438,7 +493,8 @@ static int gpio_fwd_to_irq(struct gpio_chip *chip, unsigned int offset) 
 */

static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev,

						unsigned int ngpios,

						struct gpio_desc *descs[])

						struct gpio_desc *descs[],

						unsigned long features)

{

	const char *label = dev_name(dev);

	struct gpiochip_fwd *fwd;
@@ -491,6 +547,12 @@ static struct gpiochip_fwd *gpiochip_fwd_create(struct device *dev, 
	else

		spin_lock_init(&fwd->slock);



	if (features & FWD_FEATURE_DELAY) {

		error = gpiochip_fwd_setup_delay_line(dev, chip, fwd);

		if (error)

			return ERR_PTR(error);

	}



	error = devm_gpiochip_add_data(dev, chip, fwd);

	if (error)

		return ERR_PTR(error);
@@ -508,6 +570,7 @@ static int gpio_aggregator_probe(struct platform_device *pdev) 
	struct device *dev = &pdev->dev;

	struct gpio_desc **descs;

	struct gpiochip_fwd *fwd;

	unsigned long features;

	int i, n;



	n = gpiod_count(dev, NULL);
@@ -524,7 +587,8 @@ static int gpio_aggregator_probe(struct platform_device *pdev) 
			return PTR_ERR(descs[i]);

	}



	fwd = gpiochip_fwd_create(dev, n, descs);

	features = (uintptr_t)device_get_match_data(dev);

	fwd = gpiochip_fwd_create(dev, n, descs, features);

	if (IS_ERR(fwd))

		return PTR_ERR(fwd);
@@ -533,6 +597,10 @@ static int gpio_aggregator_probe(struct platform_device *pdev) 
}



static const struct of_device_id gpio_aggregator_dt_ids[] = {

	{

		.compatible = "gpio-delay",

		.data = (void *)FWD_FEATURE_DELAY,

	},

	/*

	 * Add GPIO-operated devices controlled from userspace below,

	 * or use "driver_override" in sysfs.