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@xxxxxxxxxxxx>
---
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>
#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;
+
+ bus = of_get_child_by_name(dev->of_node, "aux-bus");
+ if (!bus)
+ return false;
+
+ panel = of_get_child_by_name(bus, "panel");
+ if (!panel)
+ return false;
+
+ return true;
+}
+
static void ps8640_ensure_hpd(struct ps8640 *ps_bridge)
{
struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
@@ -546,17 +565,6 @@ static int ps8640_probe(struct i2c_client *client)
if (!ps_bridge)
return -ENOMEM;
- /* port@1 is ps8640 output port */
- ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
- if (ret < 0)
- return ret;
- if (!panel)
- return -ENODEV;
-
- ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
- if (IS_ERR(ps_bridge->panel_bridge))
- return PTR_ERR(ps_bridge->panel_bridge);
-
ps_bridge->supplies[0].supply = "vdd33";
ps_bridge->supplies[1].supply = "vdd12";
ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
@@ -579,9 +587,16 @@ static int ps8640_probe(struct i2c_client *client)
ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
ps_bridge->bridge.of_node = dev->of_node;
- ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
+ /*
+ * In the device tree, if panel is listed under aux-bus of the bridge
+ * node, panel driver should be able to retrieve EDID by itself using
+ * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here.
+ */
+ if (!ps8640_of_panel_on_aux_bus(&client->dev))
+ ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
+
ps_bridge->page[PAGE0_DP_CNTL] = client;
ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
@@ -615,6 +630,19 @@ static int ps8640_probe(struct i2c_client *client)
if (ret)
return ret;
+ devm_of_dp_aux_populate_ep_devices(&ps_bridge->aux);
+
+ /* port@1 is ps8640 output port */
+ ret = drm_of_find_panel_or_bridge(np, 1, 0, &panel, NULL);
+ if (ret < 0)
+ return ret;
+ if (!panel)
+ return -ENODEV;
+
+ ps_bridge->panel_bridge = devm_drm_panel_bridge_add(dev, panel);
+ if (IS_ERR(ps_bridge->panel_bridge))
+ return PTR_ERR(ps_bridge->panel_bridge);
+
drm_bridge_add(&ps_bridge->bridge);
return 0;
--
2.33.0.1079.g6e70778dc9-goog
