drm/panel: nt39016: Add support for 50 Hz refresh rate

By changing the pixel clock and the length of the back porch, it is
possible to obtain a perfect 50 Hz refresh rate.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200408095830.8131-2-paul@crapouillou.net
Acked-by: Sam Ravnborg <sam@ravnborg.org>

diff --git a/drivers/gpu/drm/panel/panel-novatek-nt39016.c b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
index f1286cf..05cae8d 100644 (file)
--- a/drivers/gpu/drm/panel/panel-novatek-nt39016.c
+++ b/drivers/gpu/drm/panel/panel-novatek-nt39016.c
@@ -325,7 +325,7 @@ static int nt39016_remove(struct spi_device *spi)
 }
 
 static const struct drm_display_mode kd035g6_display_modes[] = {
-       {
+       {       /* 60 Hz */
                .clock = 6000,
                .hdisplay = 320,
                .hsync_start = 320 + 10,
@@ -338,6 +338,19 @@ static const struct drm_display_mode kd035g6_display_modes[] = {
                .vrefresh = 60,
                .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
        },
+       {       /* 50 Hz */
+               .clock = 5400,
+               .hdisplay = 320,
+               .hsync_start = 320 + 42,
+               .hsync_end = 320 + 42 + 50,
+               .htotal = 320 + 42 + 50 + 20,
+               .vdisplay = 240,
+               .vsync_start = 240 + 5,
+               .vsync_end = 240 + 5 + 1,
+               .vtotal = 240 + 5 + 1 + 4,
+               .vrefresh = 50,
+               .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+       },
 };
 
 static const struct nt39016_panel_info kd035g6_info = {