Hi Doug,
On Mon, Oct 18, 2021 at 1:43 PM Doug Anderson dianders@chromium.org wrote:
Hi,
On Sat, Oct 16, 2021 at 9:57 AM Philip Chen philipchen@chromium.org wrote:
Conventionally, panel is listed under the root in the device tree. When userland asks for display mode, ps8640 bridge is responsible for returning EDID when ps8640_bridge_get_edid() is called.
Now enable a new option of listing the panel under "aux-bus" of ps8640 bridge node in the device tree. In this case, panel driver can retrieve EDID by triggering AUX transactions, without ps8640_bridge_get_edid() calls at all.
To prevent the "old" and "new" options from interfering with each other's logic flow, disable DRM_BRIDGE_OP_EDID when the new option is taken.
Signed-off-by: Philip Chen philipchen@chromium.org
drivers/gpu/drm/bridge/parade-ps8640.c | 52 ++++++++++++++++++++------ 1 file changed, 40 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c index acfe1bf0f936..98884f799ea8 100644 --- a/drivers/gpu/drm/bridge/parade-ps8640.c +++ b/drivers/gpu/drm/bridge/parade-ps8640.c @@ -14,6 +14,7 @@ #include <linux/regulator/consumer.h>
#include <drm/drm_bridge.h> +#include <drm/drm_dp_aux_bus.h>
You need a `select DRM_DP_AUX_BUS` in the Kconfig to avoid the errors that the build robot found for you.
Thanks for the tip! I also found "select REGMAP_I2C" seems to be missing for ps8640. although the build robot didn't complain. Should I post a fix-up?
#include <drm/drm_dp_helper.h> #include <drm/drm_mipi_dsi.h> #include <drm/drm_of.h> @@ -149,6 +150,24 @@ static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux) return container_of(aux, struct ps8640, aux); }
+static bool ps8640_of_panel_on_aux_bus(struct device *dev) +{
struct device_node *bus, *panel;if (!dev->of_node)return false;You probably don't need the above check. I think things would be pretty broken if we didn't have an "of_node".
Removed in v2. PTAL.
bus = of_get_child_by_name(dev->of_node, "aux-bus");if (!bus)return false;panel = of_get_child_by_name(bus, "panel");of_node_put(bus);
Added in v2. PTAL.
if (!panel)return false;of_node_put(panel);
Added in v2. PTAL.
Other than the above, this looks reasonable to me.
-Doug