[PATCH 1/3] gpiolib: provide VALIDATE_DESC_PTR() macro

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We're about to add a public GPIO function that takes a descriptor as
argument and returns a pointer. Add a corresponding macro wrapping the
validate_desc() function that returns an ERR_PTR() on error.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/gpio/gpiolib.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 4d0106ceeba7..da8ffd40aa97 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2864,6 +2864,14 @@ static int validate_desc(const struct gpio_desc *desc, const char *func)
 		return; \
 	} while (0)
 
+#define VALIDATE_DESC_PTR(desc) do { \
+	int __valid = validate_desc(desc, __func__); \
+	if (__valid < 0) \
+		return ERR_PTR(__valid); \
+	if (__valid == 0) \
+		return NULL; \
+	} while (0)
+
 int gpiod_request(struct gpio_desc *desc, const char *label)
 {
 	int ret = -EPROBE_DEFER;
-- 
2.25.0