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/Kconfig

@@ -9,6 +9,7 @@ config DRM_I2C_ADV7511
 config DRM_I2C_ADV7533
 	bool "ADV7533 encoder"
 	depends on DRM_I2C_ADV7511
+	select DRM_MIPI_DSI
 	default y
 	help
 	  Support for the Analog Devices ADV7533 DSI to HDMI encoder.

drivers/gpu/drm/bridge/adv7511/adv7511.h

@@ -14,6 +14,7 @@
 #include <linux/regmap.h>
 
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_mipi_dsi.h>
 
 #define ADV7511_REG_CHIP_REVISION		0x00
 #define ADV7511_REG_N0				0x01
@@ -324,6 +325,11 @@ struct adv7511 {
 
 	struct gpio_desc *gpio_pd;
 
+	/* ADV7533 DSI RX related params */
+	struct device_node *host_node;
+	struct mipi_dsi_device *dsi;
+	u8 num_dsi_lanes;
+
 	enum adv7511_type type;
 };
 
@@ -333,6 +339,9 @@ void adv7533_dsi_power_off(struct adv7511 *adv);
 int adv7533_patch_registers(struct adv7511 *adv);
 void adv7533_uninit_cec(struct adv7511 *adv);
 int adv7533_init_cec(struct adv7511 *adv);
+int adv7533_attach_dsi(struct adv7511 *adv);
+void adv7533_detach_dsi(struct adv7511 *adv);
+int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv);
 #else
 static inline void adv7533_dsi_power_on(struct adv7511 *adv)
 {
@@ -355,6 +364,20 @@ static inline int adv7533_init_cec(struct adv7511 *adv)
 {
 	return -ENODEV;
 }
+
+static inline int adv7533_attach_dsi(struct adv7511 *adv)
+{
+	return -ENODEV;
+}
+
+static inline void adv7533_detach_dsi(struct adv7511 *adv)
+{
+}
+
+static inline int adv7533_parse_dt(struct device_node *np, struct adv7511 *adv)
+{
+	return -ENODEV;
+}
 #endif
 
 #endif /* __DRM_I2C_ADV7511_H__ */

drivers/gpu/drm/bridge/adv7511/adv7511_drv.c

@@ -817,6 +817,9 @@ static int adv7511_bridge_attach(struct drm_bridge *bridge)
 				 &adv7511_connector_helper_funcs);
 	drm_mode_connector_attach_encoder(&adv->connector, bridge->encoder);
 
+	if (adv->type == ADV7533)
+		ret = adv7533_attach_dsi(adv);
+
 	return ret;
 }
 
@@ -943,11 +946,12 @@ static int adv7511_probe(struct i2c_client *i2c, const struct i2c_device_id *id)
 
 	memset(&link_config, 0, sizeof(link_config));
 
-	if (adv7511->type == ADV7511) {
+	if (adv7511->type == ADV7511)
 		ret = adv7511_parse_dt(dev->of_node, &link_config);
-		if (ret)
-			return ret;
-	}
+	else
+		ret = adv7533_parse_dt(dev->of_node, adv7511);
+	if (ret)
+		return ret;
 
 	/*
 	 * The power down GPIO is optional. If present, toggle it from active to
@@ -1042,9 +1046,13 @@ static int adv7511_remove(struct i2c_client *i2c)
 {
 	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
 
+	if (adv7511->type == ADV7533) {
+		adv7533_detach_dsi(adv7511);
+		adv7533_uninit_cec(adv7511);
+	}
+
 	drm_bridge_remove(&adv7511->bridge);
 
-	adv7533_uninit_cec(adv7511);
 	i2c_unregister_device(adv7511->i2c_edid);
 
 	kfree(adv7511->edid);
@@ -1074,6 +1082,10 @@ static const struct of_device_id adv7511_of_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, adv7511_of_ids);
 
+static struct mipi_dsi_driver adv7533_dsi_driver = {
+	.driver.name = "adv7533",
+};
+
 static struct i2c_driver adv7511_driver = {
 	.driver = {
 		.name = "adv7511",
@@ -1084,7 +1096,23 @@ static struct i2c_driver adv7511_driver = {
 	.remove = adv7511_remove,
 };
 
-module_i2c_driver(adv7511_driver);
+static int __init adv7511_init(void)
+{
+	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
+		mipi_dsi_driver_register(&adv7533_dsi_driver);
+
+	return i2c_add_driver(&adv7511_driver);
+}
+module_init(adv7511_init);
+
+static void __exit adv7511_exit(void)
+{
+	i2c_del_driver(&adv7511_driver);
+
+	if (IS_ENABLED(CONFIG_DRM_MIPI_DSI))
+		mipi_dsi_driver_unregister(&adv7533_dsi_driver);
+}
+module_exit(adv7511_exit);
 
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("ADV7511 HDMI transmitter driver");

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 @@ int adv7533_init_cec(struct adv7511 *adv)
 	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;
+}