Commit e8bd92c4 authored by Hongyang Zhao's avatar Hongyang Zhao Committed by Dmitry Baryshkov
Browse files

drm/bridge: lt9611: Add support for single Port B input 



The LT9611 has two DSI input ports. The driver currently assumes Port A
is always used for single-port configurations. However, some boards
connect DSI to Port B only.

Update the driver to detect which ports are populated from devicetree
and configure the hardware accordingly:

- If only port@1 (Port B) is populated, configure port swap (0x8303
  bit 6) and byte_clk source (0x8250 bit 3:2) for Port B operation
- If both ports are populated, use dual-port mode (Port A + B)
- If only port@0 (Port A) is populated, use single Port A (existing
  behavior)

Reviewed-by: default avatarDmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Signed-off-by: default avatarHongyang Zhao <hongyang.zhao@thundersoft.com>
Reviewed-by: default avatarRoger Shimizu <rosh@debian.org>
Tested-by: default avatarRoger Shimizu <rosh@debian.org>
Link: https://patch.msgid.link/20260207-rubikpi-next-20260116-v3-2-23b9aa189a3a@thundersoft.com


Signed-off-by: default avatarDmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
parent 5ae47f51

drivers/gpu/drm/bridge/lontium-lt9611.c

+32 −14
Original line number Diff line number Diff line
@@ -116,12 +116,25 @@ static int lt9611_mipi_input_digital(struct lt9611 *lt9611, 
		{ 0x830a, 0x00 },

		{ 0x824f, 0x80 },

		{ 0x8250, 0x10 },

		{ 0x8303, 0x00 },

		{ 0x8302, 0x0a },

		{ 0x8306, 0x0a },

	};



	if (lt9611->dsi1_node)

	if (lt9611->dsi1_node) {

		if (lt9611->dsi0_node) {

			/* Dual port (Port A + B) */

			reg_cfg[1].def = 0x03;

		} else {

			/*

			 * Single port B:

			 * - 0x8303 bit 6: port swap (1=PortB as primary)

			 * - 0x8250 bit 3:2: byte_clk source (01=PortB)

			 */

			reg_cfg[3].def = 0x14;

			reg_cfg[4].def = 0x40;

		}

	}



	return regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));

}
@@ -202,7 +215,9 @@ static void lt9611_pcr_setup(struct lt9611 *lt9611, const struct drm_display_mod 
	regmap_write(lt9611->regmap, 0x831d, pol);



	regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));

	if (lt9611->dsi1_node) {



	/* dual port: configure hact for combining two DSI inputs */

	if (lt9611->dsi0_node && lt9611->dsi1_node) {

		unsigned int hact = mode->hdisplay;



		hact >>= 2;
@@ -759,7 +774,8 @@ static enum drm_mode_status lt9611_bridge_mode_valid(struct drm_bridge *bridge, 
	if (mode->hdisplay > 3840)

		return MODE_BAD_HVALUE;



	if (mode->hdisplay > 2000 && !lt9611->dsi1_node)

	/* high resolution requires dual port (Port A + B) */

	if (mode->hdisplay > 2000 && !(lt9611->dsi0_node && lt9611->dsi1_node))

		return MODE_PANEL;



	return MODE_OK;
@@ -1033,13 +1049,13 @@ static int lt9611_parse_dt(struct device *dev, 
			   struct lt9611 *lt9611)

{

	lt9611->dsi0_node = of_graph_get_remote_node(dev->of_node, 0, -1);

	if (!lt9611->dsi0_node) {

		dev_err(lt9611->dev, "failed to get remote node for primary dsi\n");

	lt9611->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);



	if (!lt9611->dsi0_node && !lt9611->dsi1_node) {

		dev_err(lt9611->dev, "failed to get remote node for dsi\n");

		return -ENODEV;

	}



	lt9611->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);



	lt9611->ac_mode = of_property_read_bool(dev->of_node, "lt,ac-mode");



	return drm_of_find_panel_or_bridge(dev->of_node, 2, -1, NULL, &lt9611->next_bridge);
@@ -1161,14 +1177,16 @@ static int lt9611_probe(struct i2c_client *client) 


	drm_bridge_add(&lt9611->bridge);



	/* Attach primary DSI */

	/* Attach primary DSI (directly drives or Port A in dual-port mode) */

	if (lt9611->dsi0_node) {

		lt9611->dsi0 = lt9611_attach_dsi(lt9611, lt9611->dsi0_node);

		if (IS_ERR(lt9611->dsi0)) {

			ret = PTR_ERR(lt9611->dsi0);

			goto err_remove_bridge;

		}

	}



	/* Attach secondary DSI, if specified */

	/* Attach secondary DSI (Port B in single or dual-port mode) */

	if (lt9611->dsi1_node) {

		lt9611->dsi1 = lt9611_attach_dsi(lt9611, lt9611->dsi1_node);

		if (IS_ERR(lt9611->dsi1)) {