[PATCH 3.13.y-ckt 134/143] gpiolib: of: allow of_gpiochip_find_and_xlate to find more than one chip per node

[Kamal Mostafa]

3.13.11-ckt18 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans Holmberg <hans.holmberg at intel.com>

commit 9cf75e9e4ddd587ac12e88e8751c358b7b27e95f upstream.

The change:

7b8792bbdffdff3abda704f89c6a45ea97afdc62
gpiolib: of: Correct error handling in of_get_named_gpiod_flags

assumed that only one gpio-chip is registred per of-node.
Some drivers register more than one chip per of-node, so
adjust the matching function of_gpiochip_find_and_xlate to
not stop looking for chips if a node-match is found and
the translation fails.

Fixes: 7b8792bbdffd ("gpiolib: of: Correct error handling in of_get_named_gpiod_flags")
Signed-off-by: Hans Holmberg <hans.holmberg at intel.com>
Acked-by: Alexandre Courbot <acourbot at nvidia.com>
Tested-by: Robert Jarzmik <robert.jarzmik at free.fr>
Tested-by: Tyler Hall <tylerwhall at gmail.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/gpio/gpiolib-of.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c
index 74ed17d..d26028c 100644
--- a/drivers/gpio/gpiolib-of.c
+++ b/drivers/gpio/gpiolib-of.c
@@ -45,12 +45,13 @@ static int of_gpiochip_find_and_xlate(struct gpio_chip *gc, void *data)
 
 	ret = gc->of_xlate(gc, &gg_data->gpiospec, gg_data->flags);
 	if (ret < 0) {
-		/* We've found the gpio chip, but the translation failed.
-		 * Return true to stop looking and return the translation
-		 * error via out_gpio
+		/* We've found a gpio chip, but the translation failed.
+		 * Store translation error in out_gpio.
+		 * Return false to keep looking, as more than one gpio chip
+		 * could be registered per of-node.
 		 */
 		gg_data->out_gpio = ERR_PTR(ret);
-		return true;
+		return false;
 	 }
 
 	gg_data->out_gpio = gpio_to_desc(ret + gc->base);
-- 
1.9.1