drm/panel: ili9341: Use predefined error codes

[ Upstream commit da85f0aaa9f21999753b01d45c0343f885a8f905 ]

In one case the -1 is returned which is quite confusing code for
the wrong device ID, in another the ret is returning instead of
plain 0 that also confusing as readed may ask the possible meaning
of positive codes, which are never the case there. Convert both
to use explicit predefined error codes to make it clear what's going
on there.

Fixes: 5a04227326b0 ("drm/panel: Add ilitek ili9341 panel driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sui Jingfeng <sui.jingfeng@linux.dev>
Link: https://lore.kernel.org/r/20240425142706.2440113-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240425142706.2440113-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
index 24c74c56e5648c47cd7af34ba088c9f86fade8a7..b933380b7eb783fad1d1101b61d7a630ade11315 100644 (file)
--- a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
+++ b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
@@ -422,7 +422,7 @@ static int ili9341_dpi_prepare(struct drm_panel *panel)
 
        ili9341_dpi_init(ili);
 
-       return ret;
+       return 0;
 }
 
 static int ili9341_dpi_enable(struct drm_panel *panel)
@@ -726,7 +726,7 @@ static int ili9341_probe(struct spi_device *spi)
        else if (!strcmp(id->name, "yx240qv29"))
                return ili9341_dbi_probe(spi, dc, reset);
 
-       return -1;
+       return -ENODEV;
 }
 
 static void ili9341_remove(struct spi_device *spi)