Unverified Commit 71f7d9c0 authored by Marek Vasut's avatar Marek Vasut Committed by Robert Foss
Browse files

drm/bridge: tc358767: Detect bridge mode from connected endpoints in DT 



The TC358767/TC358867/TC9595 are all capable of operating in multiple
modes, DPI-to-(e)DP, DSI-to-(e)DP, DSI-to-DPI. Only the first mode is
currently supported. It is possible to find out the mode in which the
bridge should be operated by testing connected endpoints in DT.

Port allocation:
port@0 - DSI input
port@1 - DPI input/output
port@2 - eDP output

Possible connections:
DPI -> port@1 -> port@2 -> eDP :: [port@0 is not connected]
DSI -> port@0 -> port@2 -> eDP :: [port@1 is not connected]
DSI -> port@0 -> port@1 -> DPI :: [port@2 is not connected]

Add function to determine the bridge mode based on connected endpoints.

Reviewed-by: default avatarLucas Stach <l.stach@pengutronix.de>
Tested-by: Lucas Stach <l.stach@pengutronix.de> # In both DPI to eDP and DSI to DPI mode.
Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Cc: Jonas Karlman <jonas@kwiboo.se>
Cc: Laurent Pinchart <Laurent.pinchart@ideasonboard.com>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: default avatarRobert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220329085015.39159-10-marex@denx.de
parent dd1fd5ab

drivers/gpu/drm/bridge/tc358767.c

+45 −1
Original line number Diff line number Diff line
@@ -1621,6 +1621,50 @@ static int tc_probe_edp_bridge_endpoint(struct tc_data *tc) 
	return ret;

}



static int tc_probe_bridge_endpoint(struct tc_data *tc)

{

	struct device *dev = tc->dev;

	struct of_endpoint endpoint;

	struct device_node *node = NULL;

	const u8 mode_dpi_to_edp = BIT(1) | BIT(2);

	const u8 mode_dsi_to_edp = BIT(0) | BIT(2);

	const u8 mode_dsi_to_dpi = BIT(0) | BIT(1);

	u8 mode = 0;



	/*

	 * Determine bridge configuration.

	 *

	 * Port allocation:

	 * port@0 - DSI input

	 * port@1 - DPI input/output

	 * port@2 - eDP output

	 *

	 * Possible connections:

	 * DPI -> port@1 -> port@2 -> eDP :: [port@0 is not connected]

	 * DSI -> port@0 -> port@2 -> eDP :: [port@1 is not connected]

	 * DSI -> port@0 -> port@1 -> DPI :: [port@2 is not connected]

	 */



	for_each_endpoint_of_node(dev->of_node, node) {

		of_graph_parse_endpoint(node, &endpoint);

		if (endpoint.port > 2)

			return -EINVAL;



		mode |= BIT(endpoint.port);

	}



	if (mode == mode_dpi_to_edp)

		return tc_probe_edp_bridge_endpoint(tc);

	else if (mode == mode_dsi_to_dpi)

		dev_warn(dev, "The mode DSI-to-DPI is not supported!\n");

	else if (mode == mode_dsi_to_edp)

		dev_warn(dev, "The mode DSI-to-(e)DP is not supported!\n");

	else

		dev_warn(dev, "Invalid mode (0x%x) is not supported!\n", mode);



	return -EINVAL;

}



static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id)

{

	struct device *dev = &client->dev;
@@ -1633,7 +1677,7 @@ static int tc_probe(struct i2c_client *client, const struct i2c_device_id *id) 


	tc->dev = dev;



	ret = tc_probe_edp_bridge_endpoint(tc);

	ret = tc_probe_bridge_endpoint(tc);

	if (ret)

		return ret;