From 28ab7d35b6e0796dd7a9a382473e2b41a68ff906 Mon Sep 17 00:00:00 2001 From: Paul Cercueil Date: Thu, 19 Nov 2020 15:55:58 +0000 Subject: [PATCH] drm/ingenic: Properly compute timings when using a 3x8-bit panel The LCD controller expects timing values in dot-clock ticks, which is 3x the timing values in pixels when using a 3x8-bit display; but it will count the display area size in pixels either way. Go figure. Signed-off-by: Paul Cercueil Reviewed-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20201119155559.14112-3-paul@crapouillou.net --- drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c index 6b668ce..27512f68 100644 --- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c +++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c @@ -644,6 +644,7 @@ static int ingenic_drm_encoder_atomic_check(struct drm_encoder *encoder, struct drm_connector_state *conn_state) { struct drm_display_info *info = &conn_state->connector->display_info; + struct drm_display_mode *mode = &crtc_state->adjusted_mode; if (info->num_bus_formats != 1) return -EINVAL; @@ -652,10 +653,22 @@ static int ingenic_drm_encoder_atomic_check(struct drm_encoder *encoder, return 0; switch (*info->bus_formats) { + case MEDIA_BUS_FMT_RGB888_3X8: + /* + * The LCD controller expects timing values in dot-clock ticks, + * which is 3x the timing values in pixels when using a 3x8-bit + * display; but it will count the display area size in pixels + * either way. Go figure. + */ + mode->crtc_clock = mode->clock * 3; + mode->crtc_hsync_start = mode->hsync_start * 3 - mode->hdisplay * 2; + mode->crtc_hsync_end = mode->hsync_end * 3 - mode->hdisplay * 2; + mode->crtc_hdisplay = mode->hdisplay; + mode->crtc_htotal = mode->htotal * 3 - mode->hdisplay * 2; + return 0; case MEDIA_BUS_FMT_RGB565_1X16: case MEDIA_BUS_FMT_RGB666_1X18: case MEDIA_BUS_FMT_RGB888_1X24: - case MEDIA_BUS_FMT_RGB888_3X8: return 0; default: return -EINVAL; -- 2.7.4