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drm/bridge: use bus flags in bridge timings 

The DRM bus flags convey additional information on pixel data on
the bus. All current available bus flags might be of interest for
a bridge. Remove the sampling_edge field and use bus_flags.

In the case at hand a dumb VGA bridge needs a specific data enable
polarity (DRM_BUS_FLAG_DE_LOW).

Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Tested-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
hifive-unleashed-5.2
Stefan Agner 2018-09-04 22:21:08 -07:00 committed by Tomi Valkeinen
parent 88bc417856
commit d23286ff3d
2 changed files with 8 additions and 10 deletions
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6
drivers/gpu/drm/bridge/dumb-vga-dac.c
View File

@ -234,7 +234,7 @@ static int dumb_vga_remove(struct platform_device *pdev)
*/
static const struct drm_bridge_timings default_dac_timings = {
/* Timing specifications, datasheet page 7 */
.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
.setup_time_ps = 500,
.hold_time_ps = 1500,
};
@ -245,7 +245,7 @@ static const struct drm_bridge_timings default_dac_timings = {
*/
static const struct drm_bridge_timings ti_ths8134_dac_timings = {
/* From timing diagram, datasheet page 9 */
.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
/* From datasheet, page 12 */
.setup_time_ps = 3000,
/* I guess this means latched input */
@ -258,7 +258,7 @@ static const struct drm_bridge_timings ti_ths8134_dac_timings = {
*/
static const struct drm_bridge_timings ti_ths8135_dac_timings = {
/* From timing diagram, datasheet page 14 */
.sampling_edge = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
.input_bus_flags = DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE,
/* From datasheet, page 16 */
.setup_time_ps = 2000,
.hold_time_ps = 500,

12
include/drm/drm_bridge.h
View File

@ -244,15 +244,13 @@ struct drm_bridge_funcs {
*/
struct drm_bridge_timings {
/**
* @sampling_edge:
* @input_bus_flags:
*
* Tells whether the bridge samples the digital input signals from the
* display engine on the positive or negative edge of the clock. This
* should use the DRM_BUS_FLAG_PIXDATA_SAMPLE_[POS|NEG]EDGE and
* DRM_BUS_FLAG_SYNC_SAMPLE_[POS|NEG]EDGE bitwise flags from the DRM
* connector (bit 2, 3, 6 and 7 valid).
* Tells what additional settings for the pixel data on the bus
* this bridge requires (like pixel signal polarity). See also
* &drm_display_info->bus_flags.
*/
u32 sampling_edge;
u32 input_bus_flags;
/**
* @setup_time_ps:
*