[PATCH] regulator: gpio: check return value of of_get_named_gpio

From: Mihai Mihalache
Date: Wed Mar 16 2016 - 11:21:12 EST

At boot time the regulator driver can be initialized before the
gpio, in which case the call to of_get_named_gpio will return
EPROBE_DEFER. This value is silently passed to regulator_register
which will return success, although the gpio is not registered
(regulator_ena_gpio_request not called) as the value passed is
detected as invalid. The gpio_regulator_probe will therefore
succeed win no gpio requested.

Signed-off-by: Mihai Mihalache <mihai.d.mihalache@xxxxxxxxx>
Reviewed-by: Hans Holmberg <hans.holmberg@xxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
drivers/regulator/gpio-regulator.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/regulator/gpio-regulator.c b/drivers/regulator/gpio-regulator.c
index a8718e98674a..83e89e5d4752 100644
--- a/drivers/regulator/gpio-regulator.c
+++ b/drivers/regulator/gpio-regulator.c
@@ -162,6 +162,8 @@ of_get_gpio_regulator_config(struct device *dev, struct device_node *np,
of_property_read_u32(np, "startup-delay-us", &config->startup_delay);

config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
+ if (config->enable_gpio == -EPROBE_DEFER)

/* Fetch GPIOs. - optional property*/
ret = of_gpio_count(np);