gpio: change gpiochip_request_own_desc() prototype

The current prototype of gpiochip_request_own_desc() requires to obtain
a pointer to a descriptor. This is in contradiction to all other GPIO
request schemes, and imposes an extra step of obtaining a descriptor to
drivers. Most drivers actually cannot even perform that step since the
function that does it (gpichip_get_desc()) is gpiolib-private.

Change gpiochip_request_own_desc() to return a descriptor from a
(chip, hwnum) tuple and update users of this function (currently
gpiolib-acpi only).

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/Documentation/gpio/driver.txt b/Documentation/gpio/driver.txt
index 18790c237977..23b751a10d7b 100644
--- a/Documentation/gpio/driver.txt
+++ b/Documentation/gpio/driver.txt
@@ -178,7 +178,8 @@ does not help since it pins the module to the kernel forever (it calls
 try_module_get()). A GPIO driver can use the following functions instead
 to request and free descriptors without being pinned to the kernel forever.
 
-        int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
+        struct gpio_desc *gpiochip_request_own_desc(struct gpio_desc *desc,
+                                                    const char *label)
 
         void gpiochip_free_own_desc(struct gpio_desc *desc)