Commit e9d9f958 authored by Philip Chen's avatar Philip Chen Committed by Douglas Anderson
Browse files

drm/bridge: parade-ps8640: Populate devices on aux-bus 



Conventionally, panel is listed under the root of 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 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: default avatarPhilip Chen <philipchen@chromium.org>
Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20211028105754.v5.2.I09899dea340f11feab97d719cb4b62bef3179e4b@changeid
parent 826cff3f

drivers/gpu/drm/bridge/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -182,6 +182,7 @@ config DRM_PARADE_PS8622 
config DRM_PARADE_PS8640

	tristate "Parade PS8640 MIPI DSI to eDP Converter"

	depends on OF

	select DRM_DP_AUX_BUS

	select DRM_KMS_HELPER

	select DRM_MIPI_DSI

	select DRM_PANEL

drivers/gpu/drm/bridge/parade-ps8640.c

+39 −12
Original line number Diff line number Diff line
@@ -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 +150,23 @@ 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;



	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);

	if (!panel)

		return false;

	of_node_put(panel);



	return true;

}



static int ps8640_ensure_hpd(struct ps8640 *ps_bridge)

{

	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
@@ -555,17 +573,6 @@ 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),
@@ -588,9 +595,16 @@ 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);
@@ -633,6 +647,19 @@ 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);



	ret = ps8640_bridge_host_attach(dev, ps_bridge);