drm/msm/dsi: external bridge support

In order for dsi to support external bridge chips, the dsi driver needs to
check whether the dsi host's child specified in DT is a bridge or a panel.

We first look for a panel node, if we don't have one, we look for a bridge. If
we connect to an external bridge, we don't need to worry about creating a
connector, the bridge driver is responsible for that.

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

Conflicts:
	drivers/gpu/drm/msm/dsi/dsi.c
	drivers/gpu/drm/msm/dsi/dsi_manager.c

4 files changed, 194 insertions, 22 deletions

diff --git a/drivers/gpu/drm/msm/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
index 1f2561e2ff718..8de8d5722762e 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.c
+++ b/drivers/gpu/drm/msm/dsi/dsi.c
@@ -223,12 +223,38 @@ int msm_dsi_modeset_init(struct msm_dsi *msm_dsi, struct drm_device *dev,
 		msm_dsi->encoders[i] = encoders[i];
 	}
 
-	msm_dsi->connector = msm_dsi_manager_connector_init(msm_dsi->id);
-	if (IS_ERR(msm_dsi->connector)) {
-		ret = PTR_ERR(msm_dsi->connector);
-		dev_err(dev->dev, "failed to create dsi connector: %d\n", ret);
-		msm_dsi->connector = NULL;
-		goto fail;
+	msm_dsi->ext_bridge = msm_dsi_host_get_ext_bridge(msm_dsi->host);
+
+	/*
+	 * skip making connector if we have a bridge. the bridge driver will take
+	 * care of creating a connector
+	 */
+	if (msm_dsi->ext_bridge) {
+		struct drm_encoder *encoder = encoders[MSM_DSI_VIDEO_ENCODER_ID];
+		struct drm_connector *connector;
+		struct drm_bridge *int_bridge = msm_dsi->bridge;
+		struct drm_bridge *ext_bridge = msm_dsi->ext_bridge;
+
+		int_bridge->next = ext_bridge;
+		ext_bridge->encoder = encoder;
+
+		drm_bridge_attach(msm_dsi->dev, ext_bridge);
+
+		/* TODO: don't just pick up the first connector, pick the one the bridge
+		 * driver just created
+		 */
+		list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
+			if (connector)
+				msm_dsi->connector = connector;
+		}
+	} else {
+		msm_dsi->connector = msm_dsi_manager_connector_init(msm_dsi->id);
+		if (IS_ERR(msm_dsi->connector)) {
+			ret = PTR_ERR(msm_dsi->connector);
+			dev_err(dev->dev, "failed to create dsi connector: %d\n", ret);
+			msm_dsi->connector = NULL;
+			goto fail;
+		}
 	}
 
 	priv->bridges[priv->num_bridges++]       = msm_dsi->bridge;
diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
index 5e29aadc0beea..fbfbc31a2d7ad 100644
--- a/drivers/gpu/drm/msm/dsi/dsi.h
+++ b/drivers/gpu/drm/msm/dsi/dsi.h
@@ -54,6 +54,7 @@ struct msm_dsi {
 	struct platform_device *pdev;
 
 	struct drm_connector *connector;
+	/* internal bridge to link to mdp5 encoder */
 	struct drm_bridge *bridge;
 
 	struct mipi_dsi_host *host;
@@ -61,7 +62,11 @@ struct msm_dsi {
 	struct drm_panel *panel;
 	unsigned long panel_flags;
 
+	/* dsi host is connected to a bridge/encoder chip */
+	struct drm_bridge *ext_bridge;
+
 	struct device *phy_dev;
+
 	bool phy_enabled;
 
 	/* the encoders we are hooked to (outside of dsi block) */
@@ -128,6 +133,7 @@ int msm_dsi_host_set_display_mode(struct mipi_dsi_host *host,
 					struct drm_display_mode *mode);
 struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host,
 					unsigned long *panel_flags);
+struct drm_bridge *msm_dsi_host_get_ext_bridge(struct mipi_dsi_host *host);
 int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer);
 void msm_dsi_host_unregister(struct mipi_dsi_host *host);
 int msm_dsi_host_set_src_pll(struct mipi_dsi_host *host,
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index de04009233035..2627570724a4b 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -219,6 +219,9 @@ struct msm_dsi_host {
 	enum mipi_dsi_pixel_format format;
 	unsigned long mode_flags;
 
+	/* external bridge info */
+	struct device_node *ext_bridge_node;
+
 	u32 dma_cmd_ctrl_restore;
 
 	bool registered;
@@ -1372,6 +1375,7 @@ static int dsi_host_attach(struct mipi_dsi_host *host,
 					struct mipi_dsi_device *dsi)
 {
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+	struct device_node *bridge, *np = msm_host->pdev->dev.of_node;
 	int ret;
 
 	msm_host->channel = dsi->channel;
@@ -1379,6 +1383,13 @@ static int dsi_host_attach(struct mipi_dsi_host *host,
 	msm_host->format = dsi->format;
 	msm_host->mode_flags = dsi->mode_flags;
 
+	/* if we have an external bridge, don't populate panel data */
+	bridge = of_get_child_by_name(np, "bridge");
+	if (bridge) {
+		of_node_put(bridge);
+		return 0;
+	}
+
 	msm_host->panel_node = dsi->dev.of_node;
 
 	/* Some gpios defined in panel DT need to be controlled by host */
@@ -1579,11 +1590,26 @@ int msm_dsi_host_register(struct mipi_dsi_host *host, bool check_defer)
 		 * create framebuffer.
 		 */
 		if (check_defer) {
+			/*
+			 * first look for a child panel node, if a panel node
+			 * exists but the corresponding panel device isn't
+			 * probed, defer msm dsi's probe
+			 *
+			 * if a child panel isn't specified at all, try to look
+			 * for a bridge phandle, defer probe if it there is a
+			 * bridge phandle but the bridge device isn't added yet
+			 */
 			node = of_get_child_by_name(msm_host->pdev->dev.of_node,
 							"panel");
 			if (node) {
 				if (!of_drm_find_panel(node))
 					return -EPROBE_DEFER;
+			} else {
+				struct drm_bridge *bridge;
+
+				bridge = msm_dsi_host_get_ext_bridge(host);
+				if (!bridge)
+					return -EPROBE_DEFER;
 			}
 		}
 	}
@@ -1882,7 +1908,6 @@ int msm_dsi_host_power_on(struct mipi_dsi_host *host)
 		DBG("dsi host already on");
 		goto unlock_ret;
 	}
-
 	ret = dsi_calc_clk_rate(msm_host);
 	if (ret) {
 		pr_err("%s: unable to calc clk rate, %d\n", __func__, ret);
@@ -2000,3 +2025,21 @@ struct drm_panel *msm_dsi_host_get_panel(struct mipi_dsi_host *host,
 	return panel;
 }
 
+struct drm_bridge *msm_dsi_host_get_ext_bridge(struct mipi_dsi_host *host)
+{
+	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
+	struct drm_bridge *bridge;
+	struct device_node *np = msm_host->pdev->dev.of_node;
+
+	msm_host->ext_bridge_node = of_get_child_by_name(np, "bridge");
+	if (!msm_host->ext_bridge_node) {
+		dev_err(&msm_host->pdev->dev, "bridge not found\n");
+		return NULL;
+	}
+
+	bridge = of_drm_find_bridge(msm_host->ext_bridge_node);
+
+	of_node_put(msm_host->ext_bridge_node);
+
+	return bridge;
+}
diff --git a/drivers/gpu/drm/msm/dsi/dsi_manager.c b/drivers/gpu/drm/msm/dsi/dsi_manager.c
index bd247b7dbc44c..829ed76ae3b71 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_manager.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_manager.c
@@ -333,7 +333,31 @@ dsi_mgr_connector_best_encoder(struct drm_connector *connector)
 	return msm_dsi_get_encoder(msm_dsi);
 }
 
-static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
+static void pre_enable_bridge(struct drm_bridge *bridge)
+{
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+	struct mipi_dsi_host *host = msm_dsi->host;
+	struct drm_bridge *ext_bridge = msm_dsi->ext_bridge;
+	int ret;
+
+	if (!ext_bridge)
+		return;
+
+	ret = msm_dsi_host_power_on(host);
+	if (ret) {
+		pr_err("%s: power on host %d failed, %d\n", __func__, id, ret);
+		return;
+	}
+
+	ret = msm_dsi_host_enable(host);
+	if (ret) {
+		pr_err("%s: enable host %d failed, %d\n", __func__, id, ret);
+		msm_dsi_host_power_off(host);
+	}
+}
+
+static void pre_enable_panel(struct drm_bridge *bridge)
 {
 	int id = dsi_mgr_bridge_get_id(bridge);
 	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
@@ -344,6 +368,7 @@ static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
 	int ret;
 
 	DBG("id=%d", id);
+
 	if (!panel || (is_dual_dsi && (DSI_1 == id)))
 		return;
 
@@ -409,17 +434,27 @@ host_on_fail:
 	return;
 }
 
-static void dsi_mgr_bridge_enable(struct drm_bridge *bridge)
+static void post_disable_bridge(struct drm_bridge *bridge)
 {
-	DBG("");
-}
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+	struct mipi_dsi_host *host = msm_dsi->host;
+	struct drm_bridge *ext_bridge = msm_dsi->ext_bridge;
+	int ret;
 
-static void dsi_mgr_bridge_disable(struct drm_bridge *bridge)
-{
-	DBG("");
+	if (!ext_bridge)
+		return;
+
+	ret = msm_dsi_host_disable(host);
+	if (ret)
+		pr_err("%s: host %d disable failed, %d\n", __func__, id, ret);
+
+	ret = msm_dsi_host_power_off(host);
+	if (ret)
+		pr_err("%s: host %d power off failed,%d\n", __func__, id, ret);
 }
 
-static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
+static void post_disable_panel(struct drm_bridge *bridge)
 {
 	int id = dsi_mgr_bridge_get_id(bridge);
 	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
@@ -464,7 +499,21 @@ static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
 	}
 }
 
-static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
+static void mode_set_bridge(struct drm_bridge *bridge,
+		struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+	struct mipi_dsi_host *host = msm_dsi->host;
+
+	if (!msm_dsi->ext_bridge)
+		return;
+
+	msm_dsi_host_set_display_mode(host, adjusted_mode);
+}
+
+static void mode_set_panel(struct drm_bridge *bridge,
 		struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
 {
@@ -474,6 +523,56 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
 	struct mipi_dsi_host *host = msm_dsi->host;
 	bool is_dual_dsi = IS_DUAL_DSI();
 
+	if (is_dual_dsi && (DSI_1 == id))
+		return;
+
+	msm_dsi_host_set_display_mode(host, adjusted_mode);
+	if (is_dual_dsi && other_dsi)
+		msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode);
+}
+/*
+ * for now, the dsi bridge functions ignore dual dsi mode if an external
+ * bridge IC is connected to it
+ */
+static void dsi_mgr_bridge_pre_enable(struct drm_bridge *bridge)
+{
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+
+	if (msm_dsi->panel)
+		pre_enable_panel(bridge);
+	else
+		pre_enable_bridge(bridge);
+}
+
+static void dsi_mgr_bridge_enable(struct drm_bridge *bridge)
+{
+	DBG("");
+}
+
+static void dsi_mgr_bridge_disable(struct drm_bridge *bridge)
+{
+	DBG("");
+}
+
+static void dsi_mgr_bridge_post_disable(struct drm_bridge *bridge)
+{
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+
+	if (msm_dsi->panel)
+		post_disable_panel(bridge);
+	else
+		post_disable_bridge(bridge);
+}
+
+static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
+		struct drm_display_mode *mode,
+		struct drm_display_mode *adjusted_mode)
+{
+	int id = dsi_mgr_bridge_get_id(bridge);
+	struct msm_dsi *msm_dsi = dsi_mgr_get_dsi(id);
+
 	DBG("set mode: %d:\"%s\" %d %d %d %d %d %d %d %d %d %d 0x%x 0x%x",
 			mode->base.id, mode->name,
 			mode->vrefresh, mode->clock,
@@ -483,12 +582,10 @@ static void dsi_mgr_bridge_mode_set(struct drm_bridge *bridge,
 			mode->vsync_end, mode->vtotal,
 			mode->type, mode->flags);
 
-	if (is_dual_dsi && (DSI_1 == id))
-		return;
-
-	msm_dsi_host_set_display_mode(host, adjusted_mode);
-	if (is_dual_dsi && other_dsi)
-		msm_dsi_host_set_display_mode(other_dsi->host, adjusted_mode);
+	if (msm_dsi->panel)
+		mode_set_panel(bridge, mode, adjusted_mode);
+	else
+		mode_set_bridge(bridge, mode, adjusted_mode);
 }
 
 static const struct drm_connector_funcs dsi_mgr_connector_funcs = {