gpiolib: import gpio_request_array() from linux 3.7

Also import related functions gpio_request_one() and
gpio_free_array().

This commit imports code from linux 3.7 as
the more recent linux kernel versions use gpiolib descriptors,
see this commit for details:

  commit 372e722ea4dd4ca11c3d04845e11cbc15f32144c
  Author: Alexandre Courbot <acourbot@nvidia.com>
  Date:   Sun Feb 3 01:29:29 2013 +0900

      gpiolib: use descriptors internally

      Make sure gpiolib works internally with descriptors and (chip, offset)
      pairs instead of using the global integer namespace. This prepares the
      ground for the removal of the global gpio_desc[] array and the
      introduction of the descriptor-based GPIO API.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 66 insertions, 0 deletions

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 03fc196546..cafef907ef 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -85,6 +85,72 @@ void gpio_free(unsigned gpio)
 	free(gi->label);
 }
 
+/**
+ * gpio_request_one - request a single GPIO with initial configuration
+ * @gpio:	the GPIO number
+ * @flags:	GPIO configuration as specified by GPIOF_*
+ * @label:	a literal description string of this GPIO
+ */
+int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
+{
+	int err;
+
+	err = gpio_request(gpio, label);
+	if (err)
+		return err;
+
+	if (flags & GPIOF_DIR_IN)
+		err = gpio_direction_input(gpio);
+	else
+		err = gpio_direction_output(gpio,
+				(flags & GPIOF_INIT_HIGH) ? 1 : 0);
+
+	if (err)
+		goto free_gpio;
+
+	return 0;
+
+ free_gpio:
+	gpio_free(gpio);
+	return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_one);
+
+/**
+ * gpio_request_array - request multiple GPIOs in a single call
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ */
+int gpio_request_array(const struct gpio *array, size_t num)
+{
+	int i, err;
+
+	for (i = 0; i < num; i++, array++) {
+		err = gpio_request_one(array->gpio, array->flags, array->label);
+		if (err)
+			goto err_free;
+	}
+	return 0;
+
+err_free:
+	while (i--)
+		gpio_free((--array)->gpio);
+	return err;
+}
+EXPORT_SYMBOL_GPL(gpio_request_array);
+
+/**
+ * gpio_free_array - release multiple GPIOs in a single call
+ * @array:	array of the 'struct gpio'
+ * @num:	how many GPIOs in the array
+ */
+void gpio_free_array(const struct gpio *array, size_t num)
+{
+	while (num--)
+		gpio_free((array++)->gpio);
+}
+EXPORT_SYMBOL_GPL(gpio_free_array);
+
 void gpio_set_value(unsigned gpio, int value)
 {
 	struct gpio_info *gi = gpio_to_desc(gpio);