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authorHaojian Zhuang <haojian.zhuang@linaro.org>2013-02-17 19:42:50 +0800
committerLinus Walleij <linus.walleij@linaro.org>2013-03-07 05:27:30 +0100
commit51e13c2475913d45a3ec546dee647538a9341d6a (patch)
tree4dc33099bddd1860ac04c6007611329b5789e2b4 /drivers/pinctrl/core.c
parentf1f70479e999217ecbf619d71837fc5d77c680fb (diff)
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>
Diffstat (limited to 'drivers/pinctrl/core.c')
-rw-r--r--drivers/pinctrl/core.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c
index e2d214c5c58..f8a632dc877 100644
--- a/drivers/pinctrl/core.c
+++ b/drivers/pinctrl/core.c
@@ -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"
@@ -277,6 +278,39 @@ pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
}
/**
+ * 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
* @outdev: the pin control device if found
@@ -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;
}