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drm/ingenic: Properly compute timings when using a 3x8-bit panel

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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 <paul@crapouillou.net>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201119155559.14112-3-paul@crapouillou.net
This commit is contained in:
Paul Cercueil 2020-11-19 15:55:58 +00:00
parent 15b7e07bcb
commit 28ab7d35b6
No known key found for this signature in database
GPG Key ID: 73EE6BD2274ABD41
1 changed files with 14 additions and 1 deletions
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15
drivers/gpu/drm/ingenic/ingenic-drm-drv.c
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@ -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;