[PATCH next] drm/sharp-memory: Fix some checks in sharp_memory_probe()

[Dan Carpenter]

The devm_drm_dev_alloc() function returns error pointers, it never
returns NULL.  Change that check to IS_ERR().

The devm_gpiod_get_optional() function returns a mix of error pointers
if there is an error, or NULL if there is no GPIO assigned.  Add a check
for error pointers.

Fixes: b8f9f21716fe ("drm/tiny: Add driver for Sharp Memory LCD")
Signed-off-by: Dan Carpenter <dan.carpenter at linaro.org>
---
 drivers/gpu/drm/tiny/sharp-memory.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tiny/sharp-memory.c b/drivers/gpu/drm/tiny/sharp-memory.c
index 2d2315bd6aef..1bcdd79166a4 100644
--- a/drivers/gpu/drm/tiny/sharp-memory.c
+++ b/drivers/gpu/drm/tiny/sharp-memory.c
@@ -543,8 +543,8 @@ static int sharp_memory_probe(struct spi_device *spi)
 
 	smd = devm_drm_dev_alloc(dev, &sharp_memory_drm_driver,
 				 struct sharp_memory_device, drm);
-	if (!smd)
-		return -ENOMEM;
+	if (IS_ERR(smd))
+		return PTR_ERR(smd);
 
 	spi_set_drvdata(spi, smd);
 
@@ -555,6 +555,8 @@ static int sharp_memory_probe(struct spi_device *spi)
 		return dev_err_probe(dev, ret, "Failed to initialize drm config\n");
 
 	smd->enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+	if (IS_ERR(smd->enable_gpio))
+		return PTR_ERR(smd->enable_gpio);
 	if (!smd->enable_gpio)
 		dev_warn(dev, "Enable gpio not defined\n");
 
-- 
2.45.2