[PATCH v3 0/7] Convert mtk-dsi to drm_bridge API and get EDID for ps8640 bridge

[PATCH v3 0/7] Convert mtk-dsi to drm_bridge API and get EDID for ps8640 bridge

[Enric Balletbo i Serra]

The PS8640 dsi-to-eDP bridge driver is using the panel bridge API,
however, not all the components in the chain have been ported to the
drm_bridge API. Actually, when a panel is attached the default panel's mode
is used, but in some cases we can't get display up if mode getting from
eDP control EDID is not chosen.

This series address that problem, first implements the .get_edid()
callback in the PS8640 driver (which is not used until the conversion is
done) and then, converts the Mediatek DSI driver to use the drm_bridge
API.

As far as I know, we're the only users of the mediatek dsi driver in
mainline, so should be safe to switch to the new chain of drm_bridge API
unconditionally.

The patches has been tested on a Acer Chromebook R13 (Elm) running a
Chrome OS userspace and checking that the valid EDID mode reported by
the bridge is selected.

[1] https://lore.kernel.org/lkml/20200210063523.133333-1-hsinyi@chromium.org/

Changes in v3:
- Replace s/bridge/next bridge/ for comment. (Laurent Pinchart)
- Add the bridge.type. (Laurent Pinchart)
- Use next_bridge field to store the panel bridge. (Laurent Pinchart)
- Add the bridge.type field. (Laurent Pinchart)
- This patch requires https://lkml.org/lkml/2020/4/16/2080 to work
  properly.
- Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)

Changes in v2:
- Do not set connector_type for panel here. (Sam Ravnborg)

Enric Balletbo i Serra (7):
  drm/bridge: ps8640: Get the EDID from eDP control
  drm/bridge_connector: Set default status connected for eDP connectors
  drm/mediatek: mtk_dsi: Rename bridge to next_bridge
  drm/mediatek: mtk_dsi: Convert to bridge driver
  drm/mediatek: mtk_dsi: Use simple encoder
  drm/mediatek: mtk_dsi: Use the drm_panel_bridge API
  drm/mediatek: mtk_dsi: Create connector for bridges

 drivers/gpu/drm/bridge/parade-ps8640.c |  12 ++
 drivers/gpu/drm/drm_bridge_connector.c |   1 +
 drivers/gpu/drm/mediatek/mtk_dsi.c     | 276 ++++++++-----------------
 3 files changed, 96 insertions(+), 193 deletions(-)

-- 
2.25.1

[PATCH v3 1/7] drm/bridge: ps8640: Get the EDID from eDP control

[Enric Balletbo i Serra]

The PS8640 DSI-to-eDP bridge can retrieve the EDID, so implement the
.get_edid callback and set the flag to indicate the core to use it.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes in v3: None
Changes in v2: None

 drivers/gpu/drm/bridge/parade-ps8640.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/bridge/parade-ps8640.c b/drivers/gpu/drm/bridge/parade-ps8640.c
index 4b099196afeb..13755d278db6 100644
--- a/drivers/gpu/drm/bridge/parade-ps8640.c
+++ b/drivers/gpu/drm/bridge/parade-ps8640.c
@@ -242,8 +242,18 @@ static int ps8640_bridge_attach(struct drm_bridge *bridge,
 	return ret;
 }
 
+static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
+					   struct drm_connector *connector)
+{
+	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
+
+	return drm_get_edid(connector,
+			    ps_bridge->page[PAGE0_DP_CNTL]->adapter);
+}
+
 static const struct drm_bridge_funcs ps8640_bridge_funcs = {
 	.attach = ps8640_bridge_attach,
+	.get_edid = ps8640_bridge_get_edid,
 	.post_disable = ps8640_post_disable,
 	.pre_enable = ps8640_pre_enable,
 };
@@ -294,6 +304,8 @@ static int ps8640_probe(struct i2c_client *client)
 
 	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
 	ps_bridge->bridge.of_node = dev->of_node;
+	ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
+	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
 
 	ps_bridge->page[PAGE0_DP_CNTL] = client;
 
-- 
2.25.1

[PATCH v3 2/7] drm/bridge_connector: Set default status connected for eDP connectors

[Enric Balletbo i Serra]

In an eDP application, HPD is not required and on most bridge chips
useless. If HPD is not used, we need to set initial status as connected,
otherwise the connector created by the drm_bridge_connector API remains
in an unknown state.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes in v3: None
Changes in v2: None

 drivers/gpu/drm/drm_bridge_connector.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/drm_bridge_connector.c b/drivers/gpu/drm/drm_bridge_connector.c
index c6994fe673f3..a58cbde59c34 100644
--- a/drivers/gpu/drm/drm_bridge_connector.c
+++ b/drivers/gpu/drm/drm_bridge_connector.c
@@ -187,6 +187,7 @@ drm_bridge_connector_detect(struct drm_connector *connector, bool force)
 		case DRM_MODE_CONNECTOR_DPI:
 		case DRM_MODE_CONNECTOR_LVDS:
 		case DRM_MODE_CONNECTOR_DSI:
+		case DRM_MODE_CONNECTOR_eDP:
 			status = connector_status_connected;
 			break;
 		default:
-- 
2.25.1

[PATCH v3 3/7] drm/mediatek: mtk_dsi: Rename bridge to next_bridge

[Enric Balletbo i Serra]

This is really a cosmetic change just to make a bit more readable the
code after convert the driver to drm_bridge. The bridge variable name
will be used by the encoder drm_bridge, and the chained bridge will be
named next_bridge.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes in v3:
- Replace s/bridge/next bridge/ for comment. (Laurent Pinchart)

Changes in v2: None

 drivers/gpu/drm/mediatek/mtk_dsi.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index cfa45d6abd74..37b8d7ffd835 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -182,7 +182,7 @@ struct mtk_dsi {
 	struct drm_encoder encoder;
 	struct drm_connector conn;
 	struct drm_panel *panel;
-	struct drm_bridge *bridge;
+	struct drm_bridge *next_bridge;
 	struct phy *phy;
 
 	void __iomem *regs;
@@ -902,9 +902,10 @@ static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
 	 */
 	dsi->encoder.possible_crtcs = 1;
 
-	/* If there's a bridge, attach to it and let it create the connector */
-	if (dsi->bridge) {
-		ret = drm_bridge_attach(&dsi->encoder, dsi->bridge, NULL, 0);
+	/* If there's a next bridge, attach to it and let it create the connector */
+	if (dsi->next_bridge) {
+		ret = drm_bridge_attach(&dsi->encoder, dsi->next_bridge, NULL,
+					0);
 		if (ret) {
 			DRM_ERROR("Failed to attach bridge to drm\n");
 			goto err_encoder_cleanup;
@@ -1185,7 +1186,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
 	}
 
 	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
-					  &dsi->panel, &dsi->bridge);
+					  &dsi->panel, &dsi->next_bridge);
 	if (ret)
 		goto err_unregister_host;
 
-- 
2.25.1

[PATCH v3 4/7] drm/mediatek: mtk_dsi: Convert to bridge driver

[Enric Balletbo i Serra]

Convert mtk_dsi to a bridge driver with built-in encoder support for
compatibility with existing component drivers.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---

Changes in v3:
- Add the bridge.type. (Laurent Pinchart)

Changes in v2: None

 drivers/gpu/drm/mediatek/mtk_dsi.c | 93 ++++++++++++++++++++++--------
 1 file changed, 69 insertions(+), 24 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 37b8d7ffd835..869ae0a2e9f8 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -180,6 +180,7 @@ struct mtk_dsi {
 	struct device *dev;
 	struct mipi_dsi_host host;
 	struct drm_encoder encoder;
+	struct drm_bridge bridge;
 	struct drm_connector conn;
 	struct drm_panel *panel;
 	struct drm_bridge *next_bridge;
@@ -205,9 +206,9 @@ struct mtk_dsi {
 	const struct mtk_dsi_driver_data *driver_data;
 };
 
-static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
+static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
 {
-	return container_of(e, struct mtk_dsi, encoder);
+	return container_of(b, struct mtk_dsi, bridge);
 }
 
 static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
@@ -796,32 +797,43 @@ static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
 	.destroy = mtk_dsi_encoder_destroy,
 };
 
-static bool mtk_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
+static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
+static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
+
+static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
+				 enum drm_bridge_attach_flags flags)
+{
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+
+	return mtk_dsi_create_conn_enc(bridge->dev, dsi);
+}
+
+static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
 {
-	return true;
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
+
+	mtk_dsi_destroy_conn_enc(dsi);
 }
 
-static void mtk_dsi_encoder_mode_set(struct drm_encoder *encoder,
-				     struct drm_display_mode *mode,
-				     struct drm_display_mode *adjusted)
+static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
+				    const struct drm_display_mode *mode,
+				    const struct drm_display_mode *adjusted)
 {
-	struct mtk_dsi *dsi = encoder_to_dsi(encoder);
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
 	drm_display_mode_to_videomode(adjusted, &dsi->vm);
 }
 
-static void mtk_dsi_encoder_disable(struct drm_encoder *encoder)
+static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
 {
-	struct mtk_dsi *dsi = encoder_to_dsi(encoder);
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
 	mtk_output_dsi_disable(dsi);
 }
 
-static void mtk_dsi_encoder_enable(struct drm_encoder *encoder)
+static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
 {
-	struct mtk_dsi *dsi = encoder_to_dsi(encoder);
+	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
 	mtk_output_dsi_enable(dsi);
 }
@@ -833,11 +845,12 @@ static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
 	return drm_panel_get_modes(dsi->panel, connector);
 }
 
-static const struct drm_encoder_helper_funcs mtk_dsi_encoder_helper_funcs = {
-	.mode_fixup = mtk_dsi_encoder_mode_fixup,
-	.mode_set = mtk_dsi_encoder_mode_set,
-	.disable = mtk_dsi_encoder_disable,
-	.enable = mtk_dsi_encoder_enable,
+static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
+	.attach = mtk_dsi_bridge_attach,
+	.detach = mtk_dsi_bridge_detach,
+	.disable = mtk_dsi_bridge_disable,
+	.enable = mtk_dsi_bridge_enable,
+	.mode_set = mtk_dsi_bridge_mode_set,
 };
 
 static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
@@ -1123,6 +1136,34 @@ static const struct mipi_dsi_host_ops mtk_dsi_ops = {
 	.transfer = mtk_dsi_host_transfer,
 };
 
+static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
+{
+	int ret;
+
+	ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
+			       DRM_MODE_ENCODER_DSI, NULL);
+	if (ret) {
+		DRM_ERROR("Failed to encoder init to drm\n");
+		return ret;
+	}
+
+	/*
+	 * Currently display data paths are statically assigned to a crtc each.
+	 * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
+	 */
+	dsi->encoder.possible_crtcs = 1;
+
+	ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
+	if (ret)
+		goto err_cleanup_encoder;
+
+	return 0;
+
+err_cleanup_encoder:
+	drm_encoder_cleanup(&dsi->encoder);
+	return ret;
+}
+
 static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 {
 	int ret;
@@ -1136,11 +1177,9 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
 		return ret;
 	}
 
-	ret = mtk_dsi_create_conn_enc(drm, dsi);
-	if (ret) {
-		DRM_ERROR("Encoder create failed with %d\n", ret);
+	ret = mtk_dsi_encoder_init(drm, dsi);
+	if (ret)
 		goto err_unregister;
-	}
 
 	return 0;
 
@@ -1155,7 +1194,6 @@ static void mtk_dsi_unbind(struct device *dev, struct device *master,
 	struct drm_device *drm = data;
 	struct mtk_dsi *dsi = dev_get_drvdata(dev);
 
-	mtk_dsi_destroy_conn_enc(dsi);
 	mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
 }
 
@@ -1265,6 +1303,12 @@ static int mtk_dsi_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, dsi);
 
+	dsi->bridge.funcs = &mtk_dsi_bridge_funcs;
+	dsi->bridge.of_node = dev->of_node;
+	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
+
+	drm_bridge_add(&dsi->bridge);
+
 	ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to add component: %d\n", ret);
@@ -1283,6 +1327,7 @@ static int mtk_dsi_remove(struct platform_device *pdev)
 	struct mtk_dsi *dsi = platform_get_drvdata(pdev);
 
 	mtk_output_dsi_disable(dsi);
+	drm_bridge_remove(&dsi->bridge);
 	component_del(&pdev->dev, &mtk_dsi_component_ops);
 	mipi_dsi_host_unregister(&dsi->host);
 
-- 
2.25.1

[PATCH v3 5/7] drm/mediatek: mtk_dsi: Use simple encoder

[Enric Balletbo i Serra]

The mtk_dsi driver uses an empty implementation for its encoder. Replace
the code with the generic simple encoder.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes in v3: None
Changes in v2: None

 drivers/gpu/drm/mediatek/mtk_dsi.c | 14 +++-----------
 1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 869ae0a2e9f8..d68694ff00dc 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -22,6 +22,7 @@
 #include <drm/drm_panel.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
+#include <drm/drm_simple_kms_helper.h>
 
 #include "mtk_drm_ddp_comp.h"
 
@@ -788,15 +789,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
 	dsi->enabled = false;
 }
 
-static void mtk_dsi_encoder_destroy(struct drm_encoder *encoder)
-{
-	drm_encoder_cleanup(encoder);
-}
-
-static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
-	.destroy = mtk_dsi_encoder_destroy,
-};
-
 static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
 static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
 
@@ -1140,8 +1132,8 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
 {
 	int ret;
 
-	ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
-			       DRM_MODE_ENCODER_DSI, NULL);
+	ret = drm_simple_encoder_init(drm, &dsi->encoder,
+				      DRM_MODE_ENCODER_DSI);
 	if (ret) {
 		DRM_ERROR("Failed to encoder init to drm\n");
 		return ret;
-- 
2.25.1

[PATCH v3 6/7] drm/mediatek: mtk_dsi: Use the drm_panel_bridge API

[Enric Balletbo i Serra]

Replace the manual panel handling code by a drm_panel_bridge. This
simplifies the driver and allows all components in the display pipeline
to be treated as bridges, paving the way to generic connector handling.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

Changes in v3:
- Use next_bridge field to store the panel bridge. (Laurent Pinchart)
- Add the bridge.type field. (Laurent Pinchart)
- This patch requires https://lkml.org/lkml/2020/4/16/2080 to work
  properly.

Changes in v2:
- Do not set connector_type for panel here. (Sam Ravnborg)

 drivers/gpu/drm/mediatek/mtk_dsi.c | 187 +++--------------------------
 1 file changed, 14 insertions(+), 173 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index d68694ff00dc..157097c63b23 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -182,8 +182,6 @@ struct mtk_dsi {
 	struct mipi_dsi_host host;
 	struct drm_encoder encoder;
 	struct drm_bridge bridge;
-	struct drm_connector conn;
-	struct drm_panel *panel;
 	struct drm_bridge *next_bridge;
 	struct phy *phy;
 
@@ -212,11 +210,6 @@ static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
 	return container_of(b, struct mtk_dsi, bridge);
 }
 
-static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
-{
-	return container_of(c, struct mtk_dsi, conn);
-}
-
 static inline struct mtk_dsi *host_to_dsi(struct mipi_dsi_host *h)
 {
 	return container_of(h, struct mtk_dsi, host);
@@ -682,16 +675,7 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
 	mtk_dsi_lane0_ulp_mode_leave(dsi);
 	mtk_dsi_clk_hs_mode(dsi, 0);
 
-	if (dsi->panel) {
-		if (drm_panel_prepare(dsi->panel)) {
-			DRM_ERROR("failed to prepare the panel\n");
-			goto err_disable_digital_clk;
-		}
-	}
-
 	return 0;
-err_disable_digital_clk:
-	clk_disable_unprepare(dsi->digital_clk);
 err_disable_engine_clk:
 	clk_disable_unprepare(dsi->engine_clk);
 err_phy_power_off:
@@ -718,15 +702,7 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
 	 */
 	mtk_dsi_stop(dsi);
 
-	if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
-		if (dsi->panel) {
-			if (drm_panel_unprepare(dsi->panel)) {
-				DRM_ERROR("failed to unprepare the panel\n");
-				return;
-			}
-		}
-	}
-
+	mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
 	mtk_dsi_reset_engine(dsi);
 	mtk_dsi_lane0_ulp_mode_enter(dsi);
 	mtk_dsi_clk_ulp_mode_enter(dsi);
@@ -757,19 +733,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
 
 	mtk_dsi_start(dsi);
 
-	if (dsi->panel) {
-		if (drm_panel_enable(dsi->panel)) {
-			DRM_ERROR("failed to enable the panel\n");
-			goto err_dsi_power_off;
-		}
-	}
-
 	dsi->enabled = true;
-
-	return;
-err_dsi_power_off:
-	mtk_dsi_stop(dsi);
-	mtk_dsi_poweroff(dsi);
 }
 
 static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
@@ -777,34 +741,19 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
 	if (!dsi->enabled)
 		return;
 
-	if (dsi->panel) {
-		if (drm_panel_disable(dsi->panel)) {
-			DRM_ERROR("failed to disable the panel\n");
-			return;
-		}
-	}
-
 	mtk_dsi_poweroff(dsi);
 
 	dsi->enabled = false;
 }
 
-static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
-static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
-
 static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
 				 enum drm_bridge_attach_flags flags)
 {
 	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
 
-	return mtk_dsi_create_conn_enc(bridge->dev, dsi);
-}
-
-static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
-{
-	struct mtk_dsi *dsi = bridge_to_dsi(bridge);
-
-	mtk_dsi_destroy_conn_enc(dsi);
+	/* Attach the panel or bridge to the dsi bridge */
+	return drm_bridge_attach(bridge->encoder, dsi->next_bridge,
+				 &dsi->bridge, flags);
 }
 
 static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
@@ -830,115 +779,13 @@ static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
 	mtk_output_dsi_enable(dsi);
 }
 
-static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
-{
-	struct mtk_dsi *dsi = connector_to_dsi(connector);
-
-	return drm_panel_get_modes(dsi->panel, connector);
-}
-
 static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
 	.attach = mtk_dsi_bridge_attach,
-	.detach = mtk_dsi_bridge_detach,
 	.disable = mtk_dsi_bridge_disable,
 	.enable = mtk_dsi_bridge_enable,
 	.mode_set = mtk_dsi_bridge_mode_set,
 };
 
-static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = drm_connector_cleanup,
-	.reset = drm_atomic_helper_connector_reset,
-	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
-};
-
-static const struct drm_connector_helper_funcs
-	mtk_dsi_connector_helper_funcs = {
-	.get_modes = mtk_dsi_connector_get_modes,
-};
-
-static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
-{
-	int ret;
-
-	ret = drm_connector_init(drm, &dsi->conn, &mtk_dsi_connector_funcs,
-				 DRM_MODE_CONNECTOR_DSI);
-	if (ret) {
-		DRM_ERROR("Failed to connector init to drm\n");
-		return ret;
-	}
-
-	drm_connector_helper_add(&dsi->conn, &mtk_dsi_connector_helper_funcs);
-
-	dsi->conn.dpms = DRM_MODE_DPMS_OFF;
-	drm_connector_attach_encoder(&dsi->conn, &dsi->encoder);
-
-	if (dsi->panel) {
-		ret = drm_panel_attach(dsi->panel, &dsi->conn);
-		if (ret) {
-			DRM_ERROR("Failed to attach panel to drm\n");
-			goto err_connector_cleanup;
-		}
-	}
-
-	return 0;
-
-err_connector_cleanup:
-	drm_connector_cleanup(&dsi->conn);
-	return ret;
-}
-
-static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
-{
-	int ret;
-
-	ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
-			       DRM_MODE_ENCODER_DSI, NULL);
-	if (ret) {
-		DRM_ERROR("Failed to encoder init to drm\n");
-		return ret;
-	}
-	drm_encoder_helper_add(&dsi->encoder, &mtk_dsi_encoder_helper_funcs);
-
-	/*
-	 * Currently display data paths are statically assigned to a crtc each.
-	 * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
-	 */
-	dsi->encoder.possible_crtcs = 1;
-
-	/* If there's a next bridge, attach to it and let it create the connector */
-	if (dsi->next_bridge) {
-		ret = drm_bridge_attach(&dsi->encoder, dsi->next_bridge, NULL,
-					0);
-		if (ret) {
-			DRM_ERROR("Failed to attach bridge to drm\n");
-			goto err_encoder_cleanup;
-		}
-	} else {
-		/* Otherwise create our own connector and attach to a panel */
-		ret = mtk_dsi_create_connector(drm, dsi);
-		if (ret)
-			goto err_encoder_cleanup;
-	}
-
-	return 0;
-
-err_encoder_cleanup:
-	drm_encoder_cleanup(&dsi->encoder);
-	return ret;
-}
-
-static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi)
-{
-	drm_encoder_cleanup(&dsi->encoder);
-	/* Skip connector cleanup if creation was delegated to the bridge */
-	if (dsi->conn.dev)
-		drm_connector_cleanup(&dsi->conn);
-	if (dsi->panel)
-		drm_panel_detach(dsi->panel);
-}
-
 static void mtk_dsi_ddp_start(struct mtk_ddp_comp *comp)
 {
 	struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp);
@@ -967,20 +814,6 @@ static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
 	dsi->format = device->format;
 	dsi->mode_flags = device->mode_flags;
 
-	if (dsi->conn.dev)
-		drm_helper_hpd_irq_event(dsi->conn.dev);
-
-	return 0;
-}
-
-static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
-			       struct mipi_dsi_device *device)
-{
-	struct mtk_dsi *dsi = host_to_dsi(host);
-
-	if (dsi->conn.dev)
-		drm_helper_hpd_irq_event(dsi->conn.dev);
-
 	return 0;
 }
 
@@ -1124,7 +957,6 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
 
 static const struct mipi_dsi_host_ops mtk_dsi_ops = {
 	.attach = mtk_dsi_host_attach,
-	.detach = mtk_dsi_host_detach,
 	.transfer = mtk_dsi_host_transfer,
 };
 
@@ -1198,6 +1030,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
 {
 	struct mtk_dsi *dsi;
 	struct device *dev = &pdev->dev;
+	struct drm_panel *panel;
 	struct resource *regs;
 	int irq_num;
 	int comp_id;
@@ -1216,10 +1049,18 @@ static int mtk_dsi_probe(struct platform_device *pdev)
 	}
 
 	ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
-					  &dsi->panel, &dsi->next_bridge);
+					  &panel, &dsi->next_bridge);
 	if (ret)
 		goto err_unregister_host;
 
+	if (panel) {
+		dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
+		if (IS_ERR(dsi->next_bridge)) {
+			ret = PTR_ERR(dsi->next_bridge);
+			goto err_unregister_host;
+		}
+	}
+
 	dsi->driver_data = of_device_get_match_data(dev);
 
 	dsi->engine_clk = devm_clk_get(dev, "engine");
-- 
2.25.1

[PATCH v3 7/7] drm/mediatek: mtk_dsi: Create connector for bridges

[Enric Balletbo i Serra]

Use the drm_bridge_connector helper to create a connector for pipelines
that use drm_bridge. This allows splitting connector operations across
multiple bridges when necessary, instead of having the last bridge in
the chain creating the connector and handling all connector operations
internally.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
---

Changes in v3:
- Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)

Changes in v2: None

 drivers/gpu/drm/mediatek/mtk_dsi.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 157097c63b23..85f76b01ae4d 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -17,6 +17,7 @@
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/drm_mipi_dsi.h>
 #include <drm/drm_of.h>
 #include <drm/drm_panel.h>
@@ -183,6 +184,7 @@ struct mtk_dsi {
 	struct drm_encoder encoder;
 	struct drm_bridge bridge;
 	struct drm_bridge *next_bridge;
+	struct drm_connector *connector;
 	struct phy *phy;
 
 	void __iomem *regs;
@@ -977,10 +979,19 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
 	 */
 	dsi->encoder.possible_crtcs = 1;
 
-	ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
+	ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
+				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
 	if (ret)
 		goto err_cleanup_encoder;
 
+	dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
+	if (IS_ERR(dsi->connector)) {
+		DRM_ERROR("Unable to create bridge connector\n");
+		ret = PTR_ERR(dsi->connector);
+		goto err_cleanup_encoder;
+	}
+	drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
+
 	return 0;
 
 err_cleanup_encoder:
-- 
2.25.1

Re: [PATCH v3 0/7] Convert mtk-dsi to drm_bridge API and get EDID for ps8640 bridge

[Sam Ravnborg]

On Fri, Apr 17, 2020 at 05:06:07PM +0200, Enric Balletbo i Serra wrote:
> The PS8640 dsi-to-eDP bridge driver is using the panel bridge API,
> however, not all the components in the chain have been ported to the
> drm_bridge API. Actually, when a panel is attached the default panel's mode
> is used, but in some cases we can't get display up if mode getting from
> eDP control EDID is not chosen.
> 
> This series address that problem, first implements the .get_edid()
> callback in the PS8640 driver (which is not used until the conversion is
> done) and then, converts the Mediatek DSI driver to use the drm_bridge
> API.
> 
> As far as I know, we're the only users of the mediatek dsi driver in
> mainline, so should be safe to switch to the new chain of drm_bridge API
> unconditionally.
> 
> The patches has been tested on a Acer Chromebook R13 (Elm) running a
> Chrome OS userspace and checking that the valid EDID mode reported by
> the bridge is selected.
> 
> [1] https://lore.kernel.org/lkml/20200210063523.133333-1-hsinyi@chromium.org/
> 
> Changes in v3:
> - Replace s/bridge/next bridge/ for comment. (Laurent Pinchart)
> - Add the bridge.type. (Laurent Pinchart)
> - Use next_bridge field to store the panel bridge. (Laurent Pinchart)
> - Add the bridge.type field. (Laurent Pinchart)
> - This patch requires https://lkml.org/lkml/2020/4/16/2080 to work
>   properly.
This patch is now applied to drm-misc-next.
IMO this patchset could go in now.


> - Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)
> 
> Changes in v2:
> - Do not set connector_type for panel here. (Sam Ravnborg)
> 
> Enric Balletbo i Serra (7):
>   drm/bridge: ps8640: Get the EDID from eDP control
>   drm/bridge_connector: Set default status connected for eDP connectors
>   drm/mediatek: mtk_dsi: Rename bridge to next_bridge
>   drm/mediatek: mtk_dsi: Convert to bridge driver
>   drm/mediatek: mtk_dsi: Use simple encoder
>   drm/mediatek: mtk_dsi: Use the drm_panel_bridge API
>   drm/mediatek: mtk_dsi: Create connector for bridges
All patches:
Acked-by: Sam Ravnborg <sam@ravnborg.org>


> 
>  drivers/gpu/drm/bridge/parade-ps8640.c |  12 ++
>  drivers/gpu/drm/drm_bridge_connector.c |   1 +
>  drivers/gpu/drm/mediatek/mtk_dsi.c     | 276 ++++++++-----------------
>  3 files changed, 96 insertions(+), 193 deletions(-)
> 
> -- 
> 2.25.1
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH v3 4/7] drm/mediatek: mtk_dsi: Convert to bridge driver

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>
> Convert mtk_dsi to a bridge driver with built-in encoder support for
> compatibility with existing component drivers.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> Changes in v3:
> - Add the bridge.type. (Laurent Pinchart)
>
> Changes in v2: None
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 93 ++++++++++++++++++++++--------
>  1 file changed, 69 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 37b8d7ffd835..869ae0a2e9f8 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -180,6 +180,7 @@ struct mtk_dsi {
>         struct device *dev;
>         struct mipi_dsi_host host;
>         struct drm_encoder encoder;
> +       struct drm_bridge bridge;
>         struct drm_connector conn;
>         struct drm_panel *panel;
>         struct drm_bridge *next_bridge;
> @@ -205,9 +206,9 @@ struct mtk_dsi {
>         const struct mtk_dsi_driver_data *driver_data;
>  };
>
> -static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
> +static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
>  {
> -       return container_of(e, struct mtk_dsi, encoder);
> +       return container_of(b, struct mtk_dsi, bridge);
>  }
>
>  static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
> @@ -796,32 +797,43 @@ static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
>         .destroy = mtk_dsi_encoder_destroy,
>  };
>
> -static bool mtk_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
> -                                      const struct drm_display_mode *mode,
> -                                      struct drm_display_mode *adjusted_mode)
> +static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
> +static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
> +
> +static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
> +                                enum drm_bridge_attach_flags flags)
> +{
> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +
> +       return mtk_dsi_create_conn_enc(bridge->dev, dsi);
> +}
> +
> +static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
>  {
> -       return true;
> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> +
> +       mtk_dsi_destroy_conn_enc(dsi);
>  }
>
> -static void mtk_dsi_encoder_mode_set(struct drm_encoder *encoder,
> -                                    struct drm_display_mode *mode,
> -                                    struct drm_display_mode *adjusted)
> +static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
> +                                   const struct drm_display_mode *mode,
> +                                   const struct drm_display_mode *adjusted)
>  {
> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>
>         drm_display_mode_to_videomode(adjusted, &dsi->vm);
>  }
>
> -static void mtk_dsi_encoder_disable(struct drm_encoder *encoder)
> +static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
>  {
> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>
>         mtk_output_dsi_disable(dsi);
>  }
>
> -static void mtk_dsi_encoder_enable(struct drm_encoder *encoder)
> +static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
>  {
> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>
>         mtk_output_dsi_enable(dsi);
>  }
> @@ -833,11 +845,12 @@ static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
>         return drm_panel_get_modes(dsi->panel, connector);
>  }
>
> -static const struct drm_encoder_helper_funcs mtk_dsi_encoder_helper_funcs = {
> -       .mode_fixup = mtk_dsi_encoder_mode_fixup,
> -       .mode_set = mtk_dsi_encoder_mode_set,
> -       .disable = mtk_dsi_encoder_disable,
> -       .enable = mtk_dsi_encoder_enable,
> +static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
> +       .attach = mtk_dsi_bridge_attach,
> +       .detach = mtk_dsi_bridge_detach,
> +       .disable = mtk_dsi_bridge_disable,
> +       .enable = mtk_dsi_bridge_enable,
> +       .mode_set = mtk_dsi_bridge_mode_set,
>  };
>
>  static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
> @@ -1123,6 +1136,34 @@ static const struct mipi_dsi_host_ops mtk_dsi_ops = {
>         .transfer = mtk_dsi_host_transfer,
>  };
>
> +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> +{
> +       int ret;
> +
> +       ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
> +                              DRM_MODE_ENCODER_DSI, NULL);

I'm a bit confused here. drm_encoder_init() exist here and in
mtk_dsi_create_conn_enc(). Do you plan to init encodr twice?

> +       if (ret) {
> +               DRM_ERROR("Failed to encoder init to drm\n");
> +               return ret;
> +       }
> +
> +       /*
> +        * Currently display data paths are statically assigned to a crtc each.
> +        * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
> +        */
> +       dsi->encoder.possible_crtcs = 1;
> +
> +       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> +       if (ret)
> +               goto err_cleanup_encoder;
> +
> +       return 0;
> +
> +err_cleanup_encoder:
> +       drm_encoder_cleanup(&dsi->encoder);
> +       return ret;
> +}
> +
>  static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
>  {
>         int ret;
> @@ -1136,11 +1177,9 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
>                 return ret;
>         }
>
> -       ret = mtk_dsi_create_conn_enc(drm, dsi);
> -       if (ret) {
> -               DRM_ERROR("Encoder create failed with %d\n", ret);
> +       ret = mtk_dsi_encoder_init(drm, dsi);
> +       if (ret)
>                 goto err_unregister;
> -       }
>
>         return 0;
>
> @@ -1155,7 +1194,6 @@ static void mtk_dsi_unbind(struct device *dev, struct device *master,
>         struct drm_device *drm = data;
>         struct mtk_dsi *dsi = dev_get_drvdata(dev);
>
> -       mtk_dsi_destroy_conn_enc(dsi);

There is mtk_dsi_encoder_init() in bind(), why no mtk_dsi_encoder_uninit() here?

Regards,
Chun-Kuang.

>         mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
>  }
>
> @@ -1265,6 +1303,12 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>
>         platform_set_drvdata(pdev, dsi);
>
> +       dsi->bridge.funcs = &mtk_dsi_bridge_funcs;
> +       dsi->bridge.of_node = dev->of_node;
> +       dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
> +
> +       drm_bridge_add(&dsi->bridge);
> +
>         ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
>         if (ret) {
>                 dev_err(&pdev->dev, "failed to add component: %d\n", ret);
> @@ -1283,6 +1327,7 @@ static int mtk_dsi_remove(struct platform_device *pdev)
>         struct mtk_dsi *dsi = platform_get_drvdata(pdev);
>
>         mtk_output_dsi_disable(dsi);
> +       drm_bridge_remove(&dsi->bridge);
>         component_del(&pdev->dev, &mtk_dsi_component_ops);
>         mipi_dsi_host_unregister(&dsi->host);
>
> --
> 2.25.1
>

Re: [PATCH v3 5/7] drm/mediatek: mtk_dsi: Use simple encoder

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>
> The mtk_dsi driver uses an empty implementation for its encoder. Replace
> the code with the generic simple encoder.

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>
> Changes in v3: None
> Changes in v2: None
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 869ae0a2e9f8..d68694ff00dc 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -22,6 +22,7 @@
>  #include <drm/drm_panel.h>
>  #include <drm/drm_print.h>
>  #include <drm/drm_probe_helper.h>
> +#include <drm/drm_simple_kms_helper.h>
>
>  #include "mtk_drm_ddp_comp.h"
>
> @@ -788,15 +789,6 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
>         dsi->enabled = false;
>  }
>
> -static void mtk_dsi_encoder_destroy(struct drm_encoder *encoder)
> -{
> -       drm_encoder_cleanup(encoder);
> -}
> -
> -static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
> -       .destroy = mtk_dsi_encoder_destroy,
> -};
> -
>  static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
>  static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
>
> @@ -1140,8 +1132,8 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
>  {
>         int ret;
>
> -       ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
> -                              DRM_MODE_ENCODER_DSI, NULL);
> +       ret = drm_simple_encoder_init(drm, &dsi->encoder,
> +                                     DRM_MODE_ENCODER_DSI);
>         if (ret) {
>                 DRM_ERROR("Failed to encoder init to drm\n");
>                 return ret;
> --
> 2.25.1
>

Re: [PATCH v3 6/7] drm/mediatek: mtk_dsi: Use the drm_panel_bridge API

[Chun-Kuang Hu]

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>
> Replace the manual panel handling code by a drm_panel_bridge. This
> simplifies the driver and allows all components in the display pipeline
> to be treated as bridges, paving the way to generic connector handling.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>
> Changes in v3:
> - Use next_bridge field to store the panel bridge. (Laurent Pinchart)
> - Add the bridge.type field. (Laurent Pinchart)
> - This patch requires https://lkml.org/lkml/2020/4/16/2080 to work
>   properly.
>
> Changes in v2:
> - Do not set connector_type for panel here. (Sam Ravnborg)
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 187 +++--------------------------
>  1 file changed, 14 insertions(+), 173 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index d68694ff00dc..157097c63b23 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -182,8 +182,6 @@ struct mtk_dsi {
>         struct mipi_dsi_host host;
>         struct drm_encoder encoder;
>         struct drm_bridge bridge;
> -       struct drm_connector conn;
> -       struct drm_panel *panel;
>         struct drm_bridge *next_bridge;
>         struct phy *phy;
>
> @@ -212,11 +210,6 @@ static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
>         return container_of(b, struct mtk_dsi, bridge);
>  }
>
> -static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
> -{
> -       return container_of(c, struct mtk_dsi, conn);
> -}
> -
>  static inline struct mtk_dsi *host_to_dsi(struct mipi_dsi_host *h)
>  {
>         return container_of(h, struct mtk_dsi, host);
> @@ -682,16 +675,7 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
>         mtk_dsi_lane0_ulp_mode_leave(dsi);
>         mtk_dsi_clk_hs_mode(dsi, 0);
>
> -       if (dsi->panel) {
> -               if (drm_panel_prepare(dsi->panel)) {
> -                       DRM_ERROR("failed to prepare the panel\n");
> -                       goto err_disable_digital_clk;
> -               }
> -       }
> -
>         return 0;
> -err_disable_digital_clk:
> -       clk_disable_unprepare(dsi->digital_clk);
>  err_disable_engine_clk:
>         clk_disable_unprepare(dsi->engine_clk);
>  err_phy_power_off:
> @@ -718,15 +702,7 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>          */
>         mtk_dsi_stop(dsi);
>
> -       if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
> -               if (dsi->panel) {
> -                       if (drm_panel_unprepare(dsi->panel)) {
> -                               DRM_ERROR("failed to unprepare the panel\n");
> -                               return;
> -                       }
> -               }
> -       }
> -
> +       mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>         mtk_dsi_reset_engine(dsi);
>         mtk_dsi_lane0_ulp_mode_enter(dsi);
>         mtk_dsi_clk_ulp_mode_enter(dsi);
> @@ -757,19 +733,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>
>         mtk_dsi_start(dsi);
>
> -       if (dsi->panel) {
> -               if (drm_panel_enable(dsi->panel)) {
> -                       DRM_ERROR("failed to enable the panel\n");
> -                       goto err_dsi_power_off;
> -               }
> -       }
> -
>         dsi->enabled = true;
> -
> -       return;
> -err_dsi_power_off:
> -       mtk_dsi_stop(dsi);
> -       mtk_dsi_poweroff(dsi);
>  }
>
>  static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
> @@ -777,34 +741,19 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
>         if (!dsi->enabled)
>                 return;
>
> -       if (dsi->panel) {
> -               if (drm_panel_disable(dsi->panel)) {
> -                       DRM_ERROR("failed to disable the panel\n");
> -                       return;
> -               }
> -       }
> -
>         mtk_dsi_poweroff(dsi);
>
>         dsi->enabled = false;
>  }
>
> -static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
> -static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
> -
>  static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
>                                  enum drm_bridge_attach_flags flags)
>  {
>         struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>
> -       return mtk_dsi_create_conn_enc(bridge->dev, dsi);
> -}
> -
> -static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
> -{
> -       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> -
> -       mtk_dsi_destroy_conn_enc(dsi);
> +       /* Attach the panel or bridge to the dsi bridge */
> +       return drm_bridge_attach(bridge->encoder, dsi->next_bridge,
> +                                &dsi->bridge, flags);
>  }
>
>  static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
> @@ -830,115 +779,13 @@ static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
>         mtk_output_dsi_enable(dsi);
>  }
>
> -static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
> -{
> -       struct mtk_dsi *dsi = connector_to_dsi(connector);
> -
> -       return drm_panel_get_modes(dsi->panel, connector);
> -}
> -
>  static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>         .attach = mtk_dsi_bridge_attach,
> -       .detach = mtk_dsi_bridge_detach,
>         .disable = mtk_dsi_bridge_disable,
>         .enable = mtk_dsi_bridge_enable,
>         .mode_set = mtk_dsi_bridge_mode_set,
>  };
>
> -static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
> -       .fill_modes = drm_helper_probe_single_connector_modes,
> -       .destroy = drm_connector_cleanup,
> -       .reset = drm_atomic_helper_connector_reset,
> -       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> -       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> -};
> -
> -static const struct drm_connector_helper_funcs
> -       mtk_dsi_connector_helper_funcs = {
> -       .get_modes = mtk_dsi_connector_get_modes,
> -};
> -
> -static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> -       int ret;
> -
> -       ret = drm_connector_init(drm, &dsi->conn, &mtk_dsi_connector_funcs,
> -                                DRM_MODE_CONNECTOR_DSI);
> -       if (ret) {
> -               DRM_ERROR("Failed to connector init to drm\n");
> -               return ret;
> -       }
> -
> -       drm_connector_helper_add(&dsi->conn, &mtk_dsi_connector_helper_funcs);
> -
> -       dsi->conn.dpms = DRM_MODE_DPMS_OFF;
> -       drm_connector_attach_encoder(&dsi->conn, &dsi->encoder);
> -
> -       if (dsi->panel) {
> -               ret = drm_panel_attach(dsi->panel, &dsi->conn);
> -               if (ret) {
> -                       DRM_ERROR("Failed to attach panel to drm\n");
> -                       goto err_connector_cleanup;
> -               }
> -       }
> -
> -       return 0;
> -
> -err_connector_cleanup:
> -       drm_connector_cleanup(&dsi->conn);
> -       return ret;
> -}
> -
> -static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> -       int ret;
> -
> -       ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
> -                              DRM_MODE_ENCODER_DSI, NULL);
> -       if (ret) {
> -               DRM_ERROR("Failed to encoder init to drm\n");
> -               return ret;
> -       }
> -       drm_encoder_helper_add(&dsi->encoder, &mtk_dsi_encoder_helper_funcs);
> -
> -       /*
> -        * Currently display data paths are statically assigned to a crtc each.
> -        * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
> -        */
> -       dsi->encoder.possible_crtcs = 1;
> -
> -       /* If there's a next bridge, attach to it and let it create the connector */
> -       if (dsi->next_bridge) {
> -               ret = drm_bridge_attach(&dsi->encoder, dsi->next_bridge, NULL,
> -                                       0);
> -               if (ret) {
> -                       DRM_ERROR("Failed to attach bridge to drm\n");
> -                       goto err_encoder_cleanup;
> -               }
> -       } else {
> -               /* Otherwise create our own connector and attach to a panel */
> -               ret = mtk_dsi_create_connector(drm, dsi);
> -               if (ret)
> -                       goto err_encoder_cleanup;
> -       }
> -
> -       return 0;
> -
> -err_encoder_cleanup:
> -       drm_encoder_cleanup(&dsi->encoder);
> -       return ret;
> -}
> -
> -static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi)
> -{
> -       drm_encoder_cleanup(&dsi->encoder);
> -       /* Skip connector cleanup if creation was delegated to the bridge */
> -       if (dsi->conn.dev)
> -               drm_connector_cleanup(&dsi->conn);
> -       if (dsi->panel)
> -               drm_panel_detach(dsi->panel);
> -}
> -
>  static void mtk_dsi_ddp_start(struct mtk_ddp_comp *comp)
>  {
>         struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp);
> @@ -967,20 +814,6 @@ static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
>         dsi->format = device->format;
>         dsi->mode_flags = device->mode_flags;
>
> -       if (dsi->conn.dev)
> -               drm_helper_hpd_irq_event(dsi->conn.dev);
> -
> -       return 0;
> -}
> -
> -static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> -                              struct mipi_dsi_device *device)
> -{
> -       struct mtk_dsi *dsi = host_to_dsi(host);
> -
> -       if (dsi->conn.dev)
> -               drm_helper_hpd_irq_event(dsi->conn.dev);
> -
>         return 0;
>  }
>
> @@ -1124,7 +957,6 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
>
>  static const struct mipi_dsi_host_ops mtk_dsi_ops = {
>         .attach = mtk_dsi_host_attach,
> -       .detach = mtk_dsi_host_detach,
>         .transfer = mtk_dsi_host_transfer,
>  };
>
> @@ -1198,6 +1030,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>  {
>         struct mtk_dsi *dsi;
>         struct device *dev = &pdev->dev;
> +       struct drm_panel *panel;
>         struct resource *regs;
>         int irq_num;
>         int comp_id;
> @@ -1216,10 +1049,18 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>         }
>
>         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> -                                         &dsi->panel, &dsi->next_bridge);
> +                                         &panel, &dsi->next_bridge);
>         if (ret)
>                 goto err_unregister_host;
>
> +       if (panel) {
> +               dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
> +               if (IS_ERR(dsi->next_bridge)) {
> +                       ret = PTR_ERR(dsi->next_bridge);
> +                       goto err_unregister_host;
> +               }
> +       }
> +
>         dsi->driver_data = of_device_get_match_data(dev);
>
>         dsi->engine_clk = devm_clk_get(dev, "engine");
> --
> 2.25.1
>

Re: [PATCH v3 6/7] drm/mediatek: mtk_dsi: Use the drm_panel_bridge API

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>
> Replace the manual panel handling code by a drm_panel_bridge. This
> simplifies the driver and allows all components in the display pipeline
> to be treated as bridges, paving the way to generic connector handling.
>

Reviewed-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
>
> Changes in v3:
> - Use next_bridge field to store the panel bridge. (Laurent Pinchart)
> - Add the bridge.type field. (Laurent Pinchart)
> - This patch requires https://lkml.org/lkml/2020/4/16/2080 to work
>   properly.
>
> Changes in v2:
> - Do not set connector_type for panel here. (Sam Ravnborg)
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 187 +++--------------------------
>  1 file changed, 14 insertions(+), 173 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index d68694ff00dc..157097c63b23 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -182,8 +182,6 @@ struct mtk_dsi {
>         struct mipi_dsi_host host;
>         struct drm_encoder encoder;
>         struct drm_bridge bridge;
> -       struct drm_connector conn;
> -       struct drm_panel *panel;
>         struct drm_bridge *next_bridge;
>         struct phy *phy;
>
> @@ -212,11 +210,6 @@ static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
>         return container_of(b, struct mtk_dsi, bridge);
>  }
>
> -static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
> -{
> -       return container_of(c, struct mtk_dsi, conn);
> -}
> -
>  static inline struct mtk_dsi *host_to_dsi(struct mipi_dsi_host *h)
>  {
>         return container_of(h, struct mtk_dsi, host);
> @@ -682,16 +675,7 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi)
>         mtk_dsi_lane0_ulp_mode_leave(dsi);
>         mtk_dsi_clk_hs_mode(dsi, 0);
>
> -       if (dsi->panel) {
> -               if (drm_panel_prepare(dsi->panel)) {
> -                       DRM_ERROR("failed to prepare the panel\n");
> -                       goto err_disable_digital_clk;
> -               }
> -       }
> -
>         return 0;
> -err_disable_digital_clk:
> -       clk_disable_unprepare(dsi->digital_clk);
>  err_disable_engine_clk:
>         clk_disable_unprepare(dsi->engine_clk);
>  err_phy_power_off:
> @@ -718,15 +702,7 @@ static void mtk_dsi_poweroff(struct mtk_dsi *dsi)
>          */
>         mtk_dsi_stop(dsi);
>
> -       if (!mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500)) {
> -               if (dsi->panel) {
> -                       if (drm_panel_unprepare(dsi->panel)) {
> -                               DRM_ERROR("failed to unprepare the panel\n");
> -                               return;
> -                       }
> -               }
> -       }
> -
> +       mtk_dsi_switch_to_cmd_mode(dsi, VM_DONE_INT_FLAG, 500);
>         mtk_dsi_reset_engine(dsi);
>         mtk_dsi_lane0_ulp_mode_enter(dsi);
>         mtk_dsi_clk_ulp_mode_enter(dsi);
> @@ -757,19 +733,7 @@ static void mtk_output_dsi_enable(struct mtk_dsi *dsi)
>
>         mtk_dsi_start(dsi);
>
> -       if (dsi->panel) {
> -               if (drm_panel_enable(dsi->panel)) {
> -                       DRM_ERROR("failed to enable the panel\n");
> -                       goto err_dsi_power_off;
> -               }
> -       }
> -
>         dsi->enabled = true;
> -
> -       return;
> -err_dsi_power_off:
> -       mtk_dsi_stop(dsi);
> -       mtk_dsi_poweroff(dsi);
>  }
>
>  static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
> @@ -777,34 +741,19 @@ static void mtk_output_dsi_disable(struct mtk_dsi *dsi)
>         if (!dsi->enabled)
>                 return;
>
> -       if (dsi->panel) {
> -               if (drm_panel_disable(dsi->panel)) {
> -                       DRM_ERROR("failed to disable the panel\n");
> -                       return;
> -               }
> -       }
> -
>         mtk_dsi_poweroff(dsi);
>
>         dsi->enabled = false;
>  }
>
> -static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
> -static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
> -
>  static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
>                                  enum drm_bridge_attach_flags flags)
>  {
>         struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>
> -       return mtk_dsi_create_conn_enc(bridge->dev, dsi);
> -}
> -
> -static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
> -{
> -       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
> -
> -       mtk_dsi_destroy_conn_enc(dsi);
> +       /* Attach the panel or bridge to the dsi bridge */
> +       return drm_bridge_attach(bridge->encoder, dsi->next_bridge,
> +                                &dsi->bridge, flags);
>  }
>
>  static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
> @@ -830,115 +779,13 @@ static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
>         mtk_output_dsi_enable(dsi);
>  }
>
> -static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
> -{
> -       struct mtk_dsi *dsi = connector_to_dsi(connector);
> -
> -       return drm_panel_get_modes(dsi->panel, connector);
> -}
> -
>  static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>         .attach = mtk_dsi_bridge_attach,
> -       .detach = mtk_dsi_bridge_detach,
>         .disable = mtk_dsi_bridge_disable,
>         .enable = mtk_dsi_bridge_enable,
>         .mode_set = mtk_dsi_bridge_mode_set,
>  };
>
> -static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
> -       .fill_modes = drm_helper_probe_single_connector_modes,
> -       .destroy = drm_connector_cleanup,
> -       .reset = drm_atomic_helper_connector_reset,
> -       .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
> -       .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> -};
> -
> -static const struct drm_connector_helper_funcs
> -       mtk_dsi_connector_helper_funcs = {
> -       .get_modes = mtk_dsi_connector_get_modes,
> -};
> -
> -static int mtk_dsi_create_connector(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> -       int ret;
> -
> -       ret = drm_connector_init(drm, &dsi->conn, &mtk_dsi_connector_funcs,
> -                                DRM_MODE_CONNECTOR_DSI);
> -       if (ret) {
> -               DRM_ERROR("Failed to connector init to drm\n");
> -               return ret;
> -       }
> -
> -       drm_connector_helper_add(&dsi->conn, &mtk_dsi_connector_helper_funcs);
> -
> -       dsi->conn.dpms = DRM_MODE_DPMS_OFF;
> -       drm_connector_attach_encoder(&dsi->conn, &dsi->encoder);
> -
> -       if (dsi->panel) {
> -               ret = drm_panel_attach(dsi->panel, &dsi->conn);
> -               if (ret) {
> -                       DRM_ERROR("Failed to attach panel to drm\n");
> -                       goto err_connector_cleanup;
> -               }
> -       }
> -
> -       return 0;
> -
> -err_connector_cleanup:
> -       drm_connector_cleanup(&dsi->conn);
> -       return ret;
> -}
> -
> -static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi)
> -{
> -       int ret;
> -
> -       ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
> -                              DRM_MODE_ENCODER_DSI, NULL);
> -       if (ret) {
> -               DRM_ERROR("Failed to encoder init to drm\n");
> -               return ret;
> -       }
> -       drm_encoder_helper_add(&dsi->encoder, &mtk_dsi_encoder_helper_funcs);
> -
> -       /*
> -        * Currently display data paths are statically assigned to a crtc each.
> -        * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
> -        */
> -       dsi->encoder.possible_crtcs = 1;
> -
> -       /* If there's a next bridge, attach to it and let it create the connector */
> -       if (dsi->next_bridge) {
> -               ret = drm_bridge_attach(&dsi->encoder, dsi->next_bridge, NULL,
> -                                       0);
> -               if (ret) {
> -                       DRM_ERROR("Failed to attach bridge to drm\n");
> -                       goto err_encoder_cleanup;
> -               }
> -       } else {
> -               /* Otherwise create our own connector and attach to a panel */
> -               ret = mtk_dsi_create_connector(drm, dsi);
> -               if (ret)
> -                       goto err_encoder_cleanup;
> -       }
> -
> -       return 0;
> -
> -err_encoder_cleanup:
> -       drm_encoder_cleanup(&dsi->encoder);
> -       return ret;
> -}
> -
> -static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi)
> -{
> -       drm_encoder_cleanup(&dsi->encoder);
> -       /* Skip connector cleanup if creation was delegated to the bridge */
> -       if (dsi->conn.dev)
> -               drm_connector_cleanup(&dsi->conn);
> -       if (dsi->panel)
> -               drm_panel_detach(dsi->panel);
> -}
> -
>  static void mtk_dsi_ddp_start(struct mtk_ddp_comp *comp)
>  {
>         struct mtk_dsi *dsi = container_of(comp, struct mtk_dsi, ddp_comp);
> @@ -967,20 +814,6 @@ static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
>         dsi->format = device->format;
>         dsi->mode_flags = device->mode_flags;
>
> -       if (dsi->conn.dev)
> -               drm_helper_hpd_irq_event(dsi->conn.dev);
> -
> -       return 0;
> -}
> -
> -static int mtk_dsi_host_detach(struct mipi_dsi_host *host,
> -                              struct mipi_dsi_device *device)
> -{
> -       struct mtk_dsi *dsi = host_to_dsi(host);
> -
> -       if (dsi->conn.dev)
> -               drm_helper_hpd_irq_event(dsi->conn.dev);
> -
>         return 0;
>  }
>
> @@ -1124,7 +957,6 @@ static ssize_t mtk_dsi_host_transfer(struct mipi_dsi_host *host,
>
>  static const struct mipi_dsi_host_ops mtk_dsi_ops = {
>         .attach = mtk_dsi_host_attach,
> -       .detach = mtk_dsi_host_detach,
>         .transfer = mtk_dsi_host_transfer,
>  };
>
> @@ -1198,6 +1030,7 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>  {
>         struct mtk_dsi *dsi;
>         struct device *dev = &pdev->dev;
> +       struct drm_panel *panel;
>         struct resource *regs;
>         int irq_num;
>         int comp_id;
> @@ -1216,10 +1049,18 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>         }
>
>         ret = drm_of_find_panel_or_bridge(dev->of_node, 0, 0,
> -                                         &dsi->panel, &dsi->next_bridge);
> +                                         &panel, &dsi->next_bridge);
>         if (ret)
>                 goto err_unregister_host;
>
> +       if (panel) {
> +               dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);
> +               if (IS_ERR(dsi->next_bridge)) {
> +                       ret = PTR_ERR(dsi->next_bridge);
> +                       goto err_unregister_host;
> +               }
> +       }
> +
>         dsi->driver_data = of_device_get_match_data(dev);
>
>         dsi->engine_clk = devm_clk_get(dev, "engine");
> --
> 2.25.1
>

Re: [PATCH v3 7/7] drm/mediatek: mtk_dsi: Create connector for bridges

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>
> Use the drm_bridge_connector helper to create a connector for pipelines
> that use drm_bridge. This allows splitting connector operations across
> multiple bridges when necessary, instead of having the last bridge in
> the chain creating the connector and handling all connector operations
> internally.
>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> ---
>
> Changes in v3:
> - Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)
>
> Changes in v2: None
>
>  drivers/gpu/drm/mediatek/mtk_dsi.c | 13 ++++++++++++-
>  1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> index 157097c63b23..85f76b01ae4d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> @@ -17,6 +17,7 @@
>
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
> +#include <drm/drm_bridge_connector.h>
>  #include <drm/drm_mipi_dsi.h>
>  #include <drm/drm_of.h>
>  #include <drm/drm_panel.h>
> @@ -183,6 +184,7 @@ struct mtk_dsi {
>         struct drm_encoder encoder;
>         struct drm_bridge bridge;
>         struct drm_bridge *next_bridge;
> +       struct drm_connector *connector;
>         struct phy *phy;
>
>         void __iomem *regs;
> @@ -977,10 +979,19 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
>          */
>         dsi->encoder.possible_crtcs = 1;
>
> -       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> +       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> +                               DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>         if (ret)
>                 goto err_cleanup_encoder;
>
> +       dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> +       if (IS_ERR(dsi->connector)) {
> +               DRM_ERROR("Unable to create bridge connector\n");
> +               ret = PTR_ERR(dsi->connector);
> +               goto err_cleanup_encoder;
> +       }
> +       drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> +

I'm not very clear about how brige-connector works, but why connector
does not attach to panel?

Regards,
Chun-Kuang.

>         return 0;
>
>  err_cleanup_encoder:
> --
> 2.25.1
>

Re: [PATCH v3 4/7] drm/mediatek: mtk_dsi: Convert to bridge driver

[Enric Balletbo i Serra]

Hi Chun-Kuang,

Thank you for the review.

On 1/5/20 15:21, Chun-Kuang Hu wrote:
> Hi, Enric:
> 
> Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>>
>> Convert mtk_dsi to a bridge driver with built-in encoder support for
>> compatibility with existing component drivers.
>>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>> ---
>>
>> Changes in v3:
>> - Add the bridge.type. (Laurent Pinchart)
>>
>> Changes in v2: None
>>
>>  drivers/gpu/drm/mediatek/mtk_dsi.c | 93 ++++++++++++++++++++++--------
>>  1 file changed, 69 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
>> index 37b8d7ffd835..869ae0a2e9f8 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
>> @@ -180,6 +180,7 @@ struct mtk_dsi {
>>         struct device *dev;
>>         struct mipi_dsi_host host;
>>         struct drm_encoder encoder;
>> +       struct drm_bridge bridge;
>>         struct drm_connector conn;
>>         struct drm_panel *panel;
>>         struct drm_bridge *next_bridge;
>> @@ -205,9 +206,9 @@ struct mtk_dsi {
>>         const struct mtk_dsi_driver_data *driver_data;
>>  };
>>
>> -static inline struct mtk_dsi *encoder_to_dsi(struct drm_encoder *e)
>> +static inline struct mtk_dsi *bridge_to_dsi(struct drm_bridge *b)
>>  {
>> -       return container_of(e, struct mtk_dsi, encoder);
>> +       return container_of(b, struct mtk_dsi, bridge);
>>  }
>>
>>  static inline struct mtk_dsi *connector_to_dsi(struct drm_connector *c)
>> @@ -796,32 +797,43 @@ static const struct drm_encoder_funcs mtk_dsi_encoder_funcs = {
>>         .destroy = mtk_dsi_encoder_destroy,
>>  };
>>
>> -static bool mtk_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
>> -                                      const struct drm_display_mode *mode,
>> -                                      struct drm_display_mode *adjusted_mode)
>> +static int mtk_dsi_create_conn_enc(struct drm_device *drm, struct mtk_dsi *dsi);
>> +static void mtk_dsi_destroy_conn_enc(struct mtk_dsi *dsi);
>> +
>> +static int mtk_dsi_bridge_attach(struct drm_bridge *bridge,
>> +                                enum drm_bridge_attach_flags flags)
>> +{
>> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>> +
>> +       return mtk_dsi_create_conn_enc(bridge->dev, dsi);
>> +}
>> +
>> +static void mtk_dsi_bridge_detach(struct drm_bridge *bridge)
>>  {
>> -       return true;
>> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>> +
>> +       mtk_dsi_destroy_conn_enc(dsi);
>>  }
>>
>> -static void mtk_dsi_encoder_mode_set(struct drm_encoder *encoder,
>> -                                    struct drm_display_mode *mode,
>> -                                    struct drm_display_mode *adjusted)
>> +static void mtk_dsi_bridge_mode_set(struct drm_bridge *bridge,
>> +                                   const struct drm_display_mode *mode,
>> +                                   const struct drm_display_mode *adjusted)
>>  {
>> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
>> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>>
>>         drm_display_mode_to_videomode(adjusted, &dsi->vm);
>>  }
>>
>> -static void mtk_dsi_encoder_disable(struct drm_encoder *encoder)
>> +static void mtk_dsi_bridge_disable(struct drm_bridge *bridge)
>>  {
>> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
>> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>>
>>         mtk_output_dsi_disable(dsi);
>>  }
>>
>> -static void mtk_dsi_encoder_enable(struct drm_encoder *encoder)
>> +static void mtk_dsi_bridge_enable(struct drm_bridge *bridge)
>>  {
>> -       struct mtk_dsi *dsi = encoder_to_dsi(encoder);
>> +       struct mtk_dsi *dsi = bridge_to_dsi(bridge);
>>
>>         mtk_output_dsi_enable(dsi);
>>  }
>> @@ -833,11 +845,12 @@ static int mtk_dsi_connector_get_modes(struct drm_connector *connector)
>>         return drm_panel_get_modes(dsi->panel, connector);
>>  }
>>
>> -static const struct drm_encoder_helper_funcs mtk_dsi_encoder_helper_funcs = {
>> -       .mode_fixup = mtk_dsi_encoder_mode_fixup,
>> -       .mode_set = mtk_dsi_encoder_mode_set,
>> -       .disable = mtk_dsi_encoder_disable,
>> -       .enable = mtk_dsi_encoder_enable,
>> +static const struct drm_bridge_funcs mtk_dsi_bridge_funcs = {
>> +       .attach = mtk_dsi_bridge_attach,
>> +       .detach = mtk_dsi_bridge_detach,
>> +       .disable = mtk_dsi_bridge_disable,
>> +       .enable = mtk_dsi_bridge_enable,
>> +       .mode_set = mtk_dsi_bridge_mode_set,
>>  };
>>
>>  static const struct drm_connector_funcs mtk_dsi_connector_funcs = {
>> @@ -1123,6 +1136,34 @@ static const struct mipi_dsi_host_ops mtk_dsi_ops = {
>>         .transfer = mtk_dsi_host_transfer,
>>  };
>>
>> +static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
>> +{
>> +       int ret;
>> +
>> +       ret = drm_encoder_init(drm, &dsi->encoder, &mtk_dsi_encoder_funcs,
>> +                              DRM_MODE_ENCODER_DSI, NULL);
> 
> I'm a bit confused here. drm_encoder_init() exist here and in
> mtk_dsi_create_conn_enc(). Do you plan to init encodr twice?
> 

Right, it should be removed from mtk_dsi_create_conn_enc(). I will do in next
version.

>> +       if (ret) {
>> +               DRM_ERROR("Failed to encoder init to drm\n");
>> +               return ret;
>> +       }
>> +
>> +       /*
>> +        * Currently display data paths are statically assigned to a crtc each.
>> +        * crtc 0 is OVL0 -> COLOR0 -> AAL -> OD -> RDMA0 -> UFOE -> DSI0
>> +        */
>> +       dsi->encoder.possible_crtcs = 1;
>> +
>> +       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
>> +       if (ret)
>> +               goto err_cleanup_encoder;
>> +
>> +       return 0;
>> +
>> +err_cleanup_encoder:
>> +       drm_encoder_cleanup(&dsi->encoder);
>> +       return ret;
>> +}
>> +
>>  static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
>>  {
>>         int ret;
>> @@ -1136,11 +1177,9 @@ static int mtk_dsi_bind(struct device *dev, struct device *master, void *data)
>>                 return ret;
>>         }
>>
>> -       ret = mtk_dsi_create_conn_enc(drm, dsi);
>> -       if (ret) {
>> -               DRM_ERROR("Encoder create failed with %d\n", ret);
>> +       ret = mtk_dsi_encoder_init(drm, dsi);
>> +       if (ret)
>>                 goto err_unregister;
>> -       }
>>
>>         return 0;
>>
>> @@ -1155,7 +1194,6 @@ static void mtk_dsi_unbind(struct device *dev, struct device *master,
>>         struct drm_device *drm = data;
>>         struct mtk_dsi *dsi = dev_get_drvdata(dev);
>>
>> -       mtk_dsi_destroy_conn_enc(dsi);
> 
> There is mtk_dsi_encoder_init() in bind(), why no mtk_dsi_encoder_uninit() here?
> 

Right, I need uninit the encoder but a simple call to drm_encoder_cleanup should
be enough. I don't think is needed create a new function for that. I'll do in
next version.

> Regards,
> Chun-Kuang.
> 
>>         mtk_ddp_comp_unregister(drm, &dsi->ddp_comp);
>>  }
>>
>> @@ -1265,6 +1303,12 @@ static int mtk_dsi_probe(struct platform_device *pdev)
>>
>>         platform_set_drvdata(pdev, dsi);
>>
>> +       dsi->bridge.funcs = &mtk_dsi_bridge_funcs;
>> +       dsi->bridge.of_node = dev->of_node;
>> +       dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
>> +
>> +       drm_bridge_add(&dsi->bridge);
>> +
>>         ret = component_add(&pdev->dev, &mtk_dsi_component_ops);
>>         if (ret) {
>>                 dev_err(&pdev->dev, "failed to add component: %d\n", ret);
>> @@ -1283,6 +1327,7 @@ static int mtk_dsi_remove(struct platform_device *pdev)
>>         struct mtk_dsi *dsi = platform_get_drvdata(pdev);
>>
>>         mtk_output_dsi_disable(dsi);
>> +       drm_bridge_remove(&dsi->bridge);
>>         component_del(&pdev->dev, &mtk_dsi_component_ops);
>>         mipi_dsi_host_unregister(&dsi->host);
>>
>> --
>> 2.25.1
>>

Re: [PATCH v3 7/7] drm/mediatek: mtk_dsi: Create connector for bridges

[Enric Balletbo i Serra]

Hi Chun-Kuang,

Thank you for your review.

On 1/5/20 16:26, Chun-Kuang Hu wrote:
> Hi, Enric:
> 
> Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
>>
>> Use the drm_bridge_connector helper to create a connector for pipelines
>> that use drm_bridge. This allows splitting connector operations across
>> multiple bridges when necessary, instead of having the last bridge in
>> the chain creating the connector and handling all connector operations
>> internally.
>>
>> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
>> ---
>>
>> Changes in v3:
>> - Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)
>>
>> Changes in v2: None
>>
>>  drivers/gpu/drm/mediatek/mtk_dsi.c | 13 ++++++++++++-
>>  1 file changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
>> index 157097c63b23..85f76b01ae4d 100644
>> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
>> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
>> @@ -17,6 +17,7 @@
>>
>>  #include <drm/drm_atomic_helper.h>
>>  #include <drm/drm_bridge.h>
>> +#include <drm/drm_bridge_connector.h>
>>  #include <drm/drm_mipi_dsi.h>
>>  #include <drm/drm_of.h>
>>  #include <drm/drm_panel.h>
>> @@ -183,6 +184,7 @@ struct mtk_dsi {
>>         struct drm_encoder encoder;
>>         struct drm_bridge bridge;
>>         struct drm_bridge *next_bridge;
>> +       struct drm_connector *connector;
>>         struct phy *phy;
>>
>>         void __iomem *regs;
>> @@ -977,10 +979,19 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
>>          */
>>         dsi->encoder.possible_crtcs = 1;
>>
>> -       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
>> +       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
>> +                               DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>>         if (ret)
>>                 goto err_cleanup_encoder;
>>
>> +       dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
>> +       if (IS_ERR(dsi->connector)) {
>> +               DRM_ERROR("Unable to create bridge connector\n");
>> +               ret = PTR_ERR(dsi->connector);
>> +               goto err_cleanup_encoder;
>> +       }
>> +       drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
>> +
> 
> I'm not very clear about how brige-connector works, but why connector
> does not attach to panel?
> 

Laurent or other drm maintainers might have more details than me, but, AFAIK the
drm_bridge_connector_init initializes a connector for a chain of bridges that
starts at the @encoder. At this point you don't know which bridge is connected
to the panel physically but doesn't really matter as what you know is that will
be only one connector in the  chain.

Thanks,
 Enric

> Regards,
> Chun-Kuang.
> 
>>         return 0;
>>
>>  err_cleanup_encoder:
>> --
>> 2.25.1
>>

Re: [PATCH v3 7/7] drm/mediatek: mtk_dsi: Create connector for bridges

[Chun-Kuang Hu]

Hi, Enric:

Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年5月1日 週五 下午10:59寫道：
>
> Hi Chun-Kuang,
>
> Thank you for your review.
>
> On 1/5/20 16:26, Chun-Kuang Hu wrote:
> > Hi, Enric:
> >
> > Enric Balletbo i Serra <enric.balletbo@collabora.com> 於 2020年4月17日 週五 下午11:06寫道：
> >>
> >> Use the drm_bridge_connector helper to create a connector for pipelines
> >> that use drm_bridge. This allows splitting connector operations across
> >> multiple bridges when necessary, instead of having the last bridge in
> >> the chain creating the connector and handling all connector operations
> >> internally.
> >>
> >> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
> >> ---
> >>
> >> Changes in v3:
> >> - Move the bridge.type line to the patch that adds drm_bridge support. (Laurent Pinchart)
> >>
> >> Changes in v2: None
> >>
> >>  drivers/gpu/drm/mediatek/mtk_dsi.c | 13 ++++++++++++-
> >>  1 file changed, 12 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
> >> index 157097c63b23..85f76b01ae4d 100644
> >> --- a/drivers/gpu/drm/mediatek/mtk_dsi.c
> >> +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
> >> @@ -17,6 +17,7 @@
> >>
> >>  #include <drm/drm_atomic_helper.h>
> >>  #include <drm/drm_bridge.h>
> >> +#include <drm/drm_bridge_connector.h>
> >>  #include <drm/drm_mipi_dsi.h>
> >>  #include <drm/drm_of.h>
> >>  #include <drm/drm_panel.h>
> >> @@ -183,6 +184,7 @@ struct mtk_dsi {
> >>         struct drm_encoder encoder;
> >>         struct drm_bridge bridge;
> >>         struct drm_bridge *next_bridge;
> >> +       struct drm_connector *connector;
> >>         struct phy *phy;
> >>
> >>         void __iomem *regs;
> >> @@ -977,10 +979,19 @@ static int mtk_dsi_encoder_init(struct drm_device *drm, struct mtk_dsi *dsi)
> >>          */
> >>         dsi->encoder.possible_crtcs = 1;
> >>
> >> -       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL, 0);
> >> +       ret = drm_bridge_attach(&dsi->encoder, &dsi->bridge, NULL,
> >> +                               DRM_BRIDGE_ATTACH_NO_CONNECTOR);
> >>         if (ret)
> >>                 goto err_cleanup_encoder;
> >>
> >> +       dsi->connector = drm_bridge_connector_init(drm, &dsi->encoder);
> >> +       if (IS_ERR(dsi->connector)) {
> >> +               DRM_ERROR("Unable to create bridge connector\n");
> >> +               ret = PTR_ERR(dsi->connector);
> >> +               goto err_cleanup_encoder;
> >> +       }
> >> +       drm_connector_attach_encoder(dsi->connector, &dsi->encoder);
> >> +
> >
> > I'm not very clear about how brige-connector works, but why connector
> > does not attach to panel?
> >
>
> Laurent or other drm maintainers might have more details than me, but, AFAIK the
> drm_bridge_connector_init initializes a connector for a chain of bridges that
> starts at the @encoder. At this point you don't know which bridge is connected
> to the panel physically but doesn't really matter as what you know is that will
> be only one connector in the  chain.

I think the panel is wrapped into next_bridge here,

if (panel) {
    dsi->next_bridge = devm_drm_panel_bridge_add(dev, panel);

so the next_bridge is a panel_bridge, in its attach function
panel_bridge_attach(),
according to the flag DRM_BRIDGE_ATTACH_NO_CONNECTOR, if not exist,
it would create connector and attach connector to panel.

I'm not sure this flag would exist or not, but for both case, it's strange.
If exist, you create connector in this patch but no where to attach
connector to panel.
If not exist, the next_brige would create one connector and this brige
would create another connector.

I think in your case, mtk_dsi does not directly connect to a panel, so
I need a exact explain. Or someone could test this on a
directly-connect-panel platform.

Regards,
Chun-Kuang.

>
> Thanks,
>  Enric
>
> > Regards,
> > Chun-Kuang.
> >
> >>         return 0;
> >>
> >>  err_cleanup_encoder:
> >> --
> >> 2.25.1
> >>