Re: [PATCH v7 08/10] drm: bridge: samsung-dsim: Add input_bus_flags

[Marek Vasut]

On 10/5/22 17:13, Jagan Teki wrote:

[...]


diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c 
b/drivers/gpu/drm/bridge/samsung-dsim.c
index f714e49c1eab..f5cd80641cea 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1601,6 +1601,10 @@ static const struct samsung_dsim_host_ops 
samsung_dsim_generic_host_ops = {
.unregister_host = samsung_dsim_unregister_host,
  };
  
+static const struct drm_bridge_timings samsung_dsim_bridge_timings = {

+   .input_bus_flags = DRM_BUS_FLAG_DE_LOW,
+};
+
  int samsung_dsim_probe(struct platform_device *pdev)
  {
struct device *dev = >dev;
@@ -1681,6 +1685,7 @@ int samsung_dsim_probe(struct platform_device *pdev)
  
  	dsi->bridge.funcs = _dsim_bridge_funcs;

dsi->bridge.of_node = dev->of_node;
+   dsi->bridge.timings = _dsim_bridge_timings;


Is this really valid on Exynos too ?

My impression is that the DE_LOW requirement is only needed for MX8MM/MN 
where the LCDIF-DSIM glue logic inverts the HS/VS/DE signals, while on 
all other platforms (at least MX8MP) the inversion does not take place, 
so DE is really active HIGH there.

[PATCH v7 08/10] drm: bridge: samsung-dsim: Add input_bus_flags

[Jagan Teki]

eLCDIF is expecting to have input_bus_flags as DE_LOW in order to
set active low during valid data transfer on each horizontal line.

Add DE_LOW flag via drm bridge timings.

v7, v6:
* none

v5:
* rebased based on updated bridge changes

v4, v3, v2, v1:
* none

Signed-off-by: Jagan Teki 
---
 drivers/gpu/drm/bridge/samsung-dsim.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c 
b/drivers/gpu/drm/bridge/samsung-dsim.c
index f714e49c1eab..f5cd80641cea 100644
--- a/drivers/gpu/drm/bridge/samsung-dsim.c
+++ b/drivers/gpu/drm/bridge/samsung-dsim.c
@@ -1601,6 +1601,10 @@ static const struct samsung_dsim_host_ops 
samsung_dsim_generic_host_ops = {
.unregister_host = samsung_dsim_unregister_host,
 };
 
+static const struct drm_bridge_timings samsung_dsim_bridge_timings = {
+   .input_bus_flags = DRM_BUS_FLAG_DE_LOW,
+};
+
 int samsung_dsim_probe(struct platform_device *pdev)
 {
struct device *dev = >dev;
@@ -1681,6 +1685,7 @@ int samsung_dsim_probe(struct platform_device *pdev)
 
dsi->bridge.funcs = _dsim_bridge_funcs;
dsi->bridge.of_node = dev->of_node;
+   dsi->bridge.timings = _dsim_bridge_timings;
dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
 
if (dsi->plat_data->host_ops && dsi->plat_data->host_ops->register_host)
-- 
2.25.1