drm/bridge: adv7533: Create a MIPI DSI device

In order to pass DSI specific parameters to the DSI host, we need the
driver to create a mipi_dsi_device DSI device that attaches to the
host.

Use of_graph helpers to get the DSI host DT node. Create a MIPI DSI
device using this host. Finally, attach this device to the DSI host.

Populate DT parameters (number of data lanes for now) that are required
for DSI RX to work correctly. Hardcode few other parameters (rgb,
embedded_sync) for now.

Select DRM_MIPI_DSI config option only when ADV7533 support is enabled.

Signed-off-by: Archit Taneja <architt@codeaurora.org>

drivers/gpu/drm/bridge/adv7511/adv7533.c

@@ -11,6 +11,8 @@
  * GNU General Public License for more details.
  */
 
+#include <linux/of_graph.h>
+
 #include "adv7511.h"
 
 static const struct reg_sequence adv7533_fixed_registers[] = {
@@ -39,8 +41,10 @@ static const struct regmap_config adv7533_cec_regmap_config = {
 
 void adv7533_dsi_power_on(struct adv7511 *adv)
 {
-	/* set number of dsi lanes (hardcoded to 4 for now) */
-	regmap_write(adv->regmap_cec, 0x1c, 4 << 4);
+	struct mipi_dsi_device *dsi = adv->dsi;
+
+	/* set number of dsi lanes */
+	regmap_write(adv->regmap_cec, 0x1c, dsi->lanes << 4);
 	/* disable internal timing generator */
 	regmap_write(adv->regmap_cec, 0x27, 0x0b);
 	/* enable hdmi */
@@ -98,3 +102,86 @@ err:
 	adv7533_uninit_cec(adv);
 	return ret;
 }
+
+int adv7533_attach_dsi(struct adv7511 *adv)
+{
+	struct device *dev = &adv->i2c_main->dev;
+	struct mipi_dsi_host *host;
+	struct mipi_dsi_device *dsi;
+	int ret = 0;
+	const struct mipi_dsi_device_info info = { .type = "adv7533",
+						   .channel = 0,
+						   .node = NULL,
+						 };
+
+	host = of_find_mipi_dsi_host_by_node(adv->host_node);
+	if (!host) {
+		dev_err(dev, "failed to find dsi host\n");
+		return -EPROBE_DEFER;
+	}
+
+	dsi = mipi_dsi_device_register_full(host, &info);
+	if (IS_ERR(dsi)) {
+		dev_err(dev, "failed to create dsi device\n");
+		ret = PTR_ERR(dsi);
+		goto err_dsi_device;
+	}
+
+	adv->dsi = dsi;
+
+	dsi->lanes = adv->num_dsi_lanes;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_SYNC_PULSE |
+			  MIPI_DSI_MODE_EOT_PACKET | MIPI_DSI_MODE_VIDEO_HSE;
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		dev_err(dev, "failed to attach dsi to host\n");
+		goto err_dsi_attach;
+	}
+
+	return 0;
+
+err_dsi_attach:
+	mipi_dsi_device_unregister(dsi);
+err_dsi_device:
+	return ret;
+}
+
+void adv7533_detach_dsi(struct adv7511 *adv)
+{
+	mipi_dsi_detach(adv->dsi);
+	mipi_dsi_device_unregister(adv->dsi);
+}
+
+int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
+{
+	u32 num_lanes;
+	struct device_node *endpoint;
+
+	of_property_read_u32(np, "adi,dsi-lanes", &num_lanes);
+
+	if (num_lanes < 1 || num_lanes > 4)
+		return -EINVAL;
+
+	adv->num_dsi_lanes = num_lanes;
+
+	endpoint = of_graph_get_next_endpoint(np, NULL);
+	if (!endpoint)
+		return -ENODEV;
+
+	adv->host_node = of_graph_get_remote_port_parent(endpoint);
+	if (!adv->host_node) {
+		of_node_put(endpoint);
+		return -ENODEV;
+	}
+
+	of_node_put(endpoint);
+	of_node_put(adv->host_node);
+
+	/* TODO: Check if these need to be parsed by DT or not */
+	adv->rgb = true;
+	adv->embedded_sync = false;
+
+	return 0;
+}