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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: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
hifive-unleashed-5.1
Haojian Zhuang 2013-02-17 19:42:50 +08:00 committed by Linus Walleij
parent f1f70479e9
commit 51e13c2475
1 changed files with 36 additions and 0 deletions
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36
drivers/pinctrl/core.c
View File

@ -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;
}