drm: ssd130x: Fix COM scan direction register mask

[ Upstream commit efb37e66b7572ce4696aa0ac21675e17d6b9a17d ]

The SSD130x's command to toggle COM scan direction uses bit 3 and only
bit 3 to set the direction of the scanout. The driver has an incorrect
GENMASK(3, 2), causing the setting to be set on bit 2, rendering it
ineffective.

Fix the mask to only bit 3, so that the requested setting is applied
correctly.

Fixes: a61732e80867 ("drm: Add driver for Solomon SSD130x OLED displays")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220308160758.26060-1-wens@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index ce4dc20412e06c246c5b1cd4a3192415548efe62..ccd37813558911757a0b54faf57d0addfca84e02 100644 (file)
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -61,7 +61,7 @@
 #define SSD130X_SET_COM_PINS_CONFIG            0xda
 #define SSD130X_SET_VCOMH                      0xdb
 
-#define SSD130X_SET_COM_SCAN_DIR_MASK          GENMASK(3, 2)
+#define SSD130X_SET_COM_SCAN_DIR_MASK          GENMASK(3, 3)
 #define SSD130X_SET_COM_SCAN_DIR_SET(val)      FIELD_PREP(SSD130X_SET_COM_SCAN_DIR_MASK, (val))
 #define SSD130X_SET_CLOCK_DIV_MASK             GENMASK(3, 0)
 #define SSD130X_SET_CLOCK_DIV_SET(val)         FIELD_PREP(SSD130X_SET_CLOCK_DIV_MASK, (val))