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Commit 51e13c24 authored by Haojian Zhuang's avatar Haojian Zhuang Committed by Linus Walleij
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pinctrl: check pinctrl ready for gpio range 



pinctrl_get_device_gpio_range() only checks whether a certain GPIO pin
is in gpio range. But maybe some GPIO pins don't have back-end pinctrl
interface, it means that these pins are always configured as GPIO
function. For example, gpio159 isn't related to back-end pinctrl device
in Hi3620 while other GPIO pins are related to back-end pinctrl device.

Append pinctrl_ready_for_gpio_range() that is used to check whether
pinctrl device with GPIO range is ready. This function will be called
after pinctrl_get_device_gpio_range() fails.

If pinctrl device with GPIO range is found, it means that pinctrl device
is already launched and a certain GPIO pin just don't have back-end pinctrl
interface. Then pinctrl_request_gpio() shouldn't return -EPROBE_DEFER in
this case.

Signed-off-by: default avatarHaojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent f1f70479

drivers/pinctrl/core.c

+36 −0
Original line number Diff line number Diff line
@@ -27,6 +27,7 @@ 
#include <linux/pinctrl/consumer.h>

#include <linux/pinctrl/pinctrl.h>

#include <linux/pinctrl/machine.h>

#include <asm-generic/gpio.h>

#include "core.h"

#include "devicetree.h"

#include "pinmux.h"
@@ -276,6 +277,39 @@ pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio) 
	return NULL;

}



/**

 * pinctrl_ready_for_gpio_range() - check if other GPIO pins of

 * the same GPIO chip are in range

 * @gpio: gpio pin to check taken from the global GPIO pin space

 *

 * This function is complement of pinctrl_match_gpio_range(). If the return

 * value of pinctrl_match_gpio_range() is NULL, this function could be used

 * to check whether pinctrl device is ready or not. Maybe some GPIO pins

 * of the same GPIO chip don't have back-end pinctrl interface.

 * If the return value is true, it means that pinctrl device is ready & the

 * certain GPIO pin doesn't have back-end pinctrl device. If the return value

 * is false, it means that pinctrl device may not be ready.

 */

static bool pinctrl_ready_for_gpio_range(unsigned gpio)

{

	struct pinctrl_dev *pctldev;

	struct pinctrl_gpio_range *range = NULL;

	struct gpio_chip *chip = gpio_to_chip(gpio);



	/* Loop over the pin controllers */

	list_for_each_entry(pctldev, &pinctrldev_list, node) {

		/* Loop over the ranges */

		list_for_each_entry(range, &pctldev->gpio_ranges, node) {

			/* Check if any gpio range overlapped with gpio chip */

			if (range->base + range->npins - 1 < chip->base ||

			    range->base > chip->base + chip->ngpio - 1)

				continue;

			return true;

		}

	}

	return false;

}



/**

 * pinctrl_get_device_gpio_range() - find device for GPIO range

 * @gpio: the pin to locate the pin controller for
@@ -443,6 +477,8 @@ int pinctrl_request_gpio(unsigned gpio) 


	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);

	if (ret) {

		if (pinctrl_ready_for_gpio_range(gpio))

			ret = 0;

		mutex_unlock(&pinctrl_mutex);

		return ret;

	}