gpio: return NULL from gpiod_get_optional when GPIOLIB is disabled

Given the intent behind gpiod_get_optional() and friends it does not make
sense to return -ENOSYS when GPIOLIB is disabled: the driver is expected to
work just fine without gpio so let's behave as if gpio was not found.
Otherwise we have to special-case -ENOSYS in drivers.

Note that there was objection that someone might forget to enable GPIOLIB
when dealing with a platform that has device that actually specifies
optional gpio and we'll break it. I find this unconvincing as that would
have to be the *only GPIO* in the system, which is extremely unlikely.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 6 insertions, 6 deletions

diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h
index 2484b2fcc6eb..13daf08e25bb 100644
--- a/include/linux/gpio/consumer.h
+++ b/include/linux/gpio/consumer.h
@@ -179,14 +179,14 @@ static inline struct gpio_desc *__must_check
 gpiod_get_optional(struct device *dev, const char *con_id,
                    enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline struct gpio_desc *__must_check
 gpiod_get_index_optional(struct device *dev, const char *con_id,
                          unsigned int index, enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline struct gpio_descs *__must_check
@@ -200,7 +200,7 @@ static inline struct gpio_descs *__must_check
 gpiod_get_array_optional(struct device *dev, const char *con_id,
                          enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline void gpiod_put(struct gpio_desc *desc)
@@ -240,14 +240,14 @@ static inline struct gpio_desc *__must_check
 devm_gpiod_get_optional(struct device *dev, const char *con_id,
                           enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline struct gpio_desc *__must_check
 devm_gpiod_get_index_optional(struct device *dev, const char *con_id,
                                 unsigned int index, enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline struct gpio_descs *__must_check
@@ -261,7 +261,7 @@ static inline struct gpio_descs *__must_check
 devm_gpiod_get_array_optional(struct device *dev, const char *con_id,
                               enum gpiod_flags flags)
 {
-        return ERR_PTR(-ENOSYS);
+        return NULL;
 }
 
 static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc)