@@ -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"
@@ -293,6 +294,39 @@ pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
}
/**
+ * pinctrl_overlapped_gpio_range() - check if the GPIO chip of a certain GPIO
+ * pin is overlapped with gpio 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
+ * 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_overlapped_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
@@ -459,6 +493,8 @@ int pinctrl_request_gpio(unsigned gpio)
ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
if (ret) {
+ if (pinctrl_overlapped_gpio_range(gpio))
+ ret = 0;
mutex_unlock(&pinctrl_mutex);
return ret;
}
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. Append pinctrl_overlapped_gpio_range() that is used to check whether the pins of GPIO chip are overlapped with pins in the GPIO range. This function will be called after pinctrl_get_device_gpio_range() fails. If overlapped GPIO pins are found, it means that pinctrl device is already launched and a certain GPIO pin 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> --- drivers/pinctrl/core.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)