From 4c3d525f65733e760f3700c0f3c83e8e46d2dcd8 Mon Sep 17 00:00:00 2001
From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Date: Sun, 2 Jun 2024 15:04:50 +0300
Subject: [PATCH] drm/imx: ldb: switch to imx_legacy_bridge /
 drm_bridge_connector

Use the imx_legacy bridge driver instead of handlign display modes via
the connector node.

All existing usecases already support attaching using
the DRM_BRIDGE_ATTACH_NO_CONNECTOR flag, while the imx_legacy bridge
doesn't support creating connector at all. Switch to
drm_bridge_connector at the same time.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Chris Healy <cphealy@gmail.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # on imx6q-nitrogen6x
Link: https://patchwork.freedesktop.org/patch/msgid/20240602-drm-imx-cleanup-v3-10-e549e2a43100@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/imx/ipuv3/Kconfig   |   1 +
 drivers/gpu/drm/imx/ipuv3/imx-ldb.c | 103 ++++++++--------------------
 2 files changed, 30 insertions(+), 74 deletions(-)

diff --git a/drivers/gpu/drm/imx/ipuv3/Kconfig b/drivers/gpu/drm/imx/ipuv3/Kconfig
index f083d313d1d3a..5a40c878ebb05 100644
--- a/drivers/gpu/drm/imx/ipuv3/Kconfig
+++ b/drivers/gpu/drm/imx/ipuv3/Kconfig
@@ -32,6 +32,7 @@ config DRM_IMX_LDB
 	select MFD_SYSCON
 	select DRM_BRIDGE
 	select DRM_PANEL_BRIDGE
+	select DRM_IMX_LEGACY_BRIDGE
 	help
 	  Choose this to enable the internal LVDS Display Bridge (LDB)
 	  found on i.MX53 and i.MX6 processors.
diff --git a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
index bc7ad96971308..ff74018ac5cdf 100644
--- a/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
+++ b/drivers/gpu/drm/imx/ipuv3/imx-ldb.c
@@ -19,17 +19,16 @@
 #include <linux/regmap.h>
 #include <linux/videodev2.h>
 
-#include <video/of_display_timing.h>
-#include <video/of_videomode.h>
-
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/drm_managed.h>
 #include <drm/drm_of.h>
 #include <drm/drm_print.h>
 #include <drm/drm_probe_helper.h>
 #include <drm/drm_simple_kms_helper.h>
+#include <drm/bridge/imx.h>
 
 #include "imx-drm.h"
 
@@ -53,7 +52,6 @@
 struct imx_ldb_channel;
 
 struct imx_ldb_encoder {
-	struct drm_connector connector;
 	struct drm_encoder encoder;
 	struct imx_ldb_channel *channel;
 };
@@ -67,17 +65,9 @@ struct imx_ldb_channel {
 
 	struct device_node *child;
 	int chno;
-	struct drm_display_mode mode;
-	int mode_valid;
 	u32 bus_format;
-	u32 bus_flags;
 };
 
-static inline struct imx_ldb_channel *con_to_imx_ldb_ch(struct drm_connector *c)
-{
-	return container_of(c, struct imx_ldb_encoder, connector)->channel;
-}
-
 static inline struct imx_ldb_channel *enc_to_imx_ldb_ch(struct drm_encoder *e)
 {
 	return container_of(e, struct imx_ldb_encoder, encoder)->channel;
@@ -127,25 +117,6 @@ static void imx_ldb_ch_set_bus_format(struct imx_ldb_channel *imx_ldb_ch,
 	}
 }
 
-static int imx_ldb_connector_get_modes(struct drm_connector *connector)
-{
-	struct imx_ldb_channel *imx_ldb_ch = con_to_imx_ldb_ch(connector);
-	int num_modes;
-
-	if (imx_ldb_ch->mode_valid) {
-		struct drm_display_mode *mode;
-
-		mode = drm_mode_duplicate(connector->dev, &imx_ldb_ch->mode);
-		if (!mode)
-			return -EINVAL;
-		mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
-		drm_mode_probed_add(connector, mode);
-		num_modes++;
-	}
-
-	return num_modes;
-}
-
 static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
 		unsigned long serial_clk, unsigned long di_clk)
 {
@@ -347,11 +318,12 @@ static int imx_ldb_encoder_atomic_check(struct drm_encoder *encoder,
 	/* Bus format description in DT overrides connector display info. */
 	if (!bus_format && di->num_bus_formats) {
 		bus_format = di->bus_formats[0];
-		imx_crtc_state->bus_flags = di->bus_flags;
 	} else {
 		bus_format = imx_ldb_ch->bus_format;
-		imx_crtc_state->bus_flags = imx_ldb_ch->bus_flags;
 	}
+
+	imx_crtc_state->bus_flags = di->bus_flags;
+
 	switch (bus_format) {
 	case MEDIA_BUS_FMT_RGB666_1X7X3_SPWG:
 		imx_crtc_state->bus_format = MEDIA_BUS_FMT_RGB666_1X18;
@@ -371,18 +343,6 @@ static int imx_ldb_encoder_atomic_check(struct drm_encoder *encoder,
 }
 
 
-static const struct drm_connector_funcs imx_ldb_connector_funcs = {
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = imx_drm_connector_destroy,
-	.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 imx_ldb_connector_helper_funcs = {
-	.get_modes = imx_ldb_connector_get_modes,
-};
-
 static const struct drm_encoder_helper_funcs imx_ldb_encoder_helper_funcs = {
 	.atomic_mode_set = imx_ldb_encoder_atomic_mode_set,
 	.enable = imx_ldb_encoder_enable,
@@ -420,7 +380,6 @@ static int imx_ldb_register(struct drm_device *drm,
 		return PTR_ERR(ldb_encoder);
 
 	ldb_encoder->channel = imx_ldb_ch;
-	connector = &ldb_encoder->connector;
 	encoder = &ldb_encoder->encoder;
 
 	ret = imx_drm_encoder_parse_of(drm, encoder, imx_ldb_ch->child);
@@ -439,24 +398,16 @@ static int imx_ldb_register(struct drm_device *drm,
 
 	drm_encoder_helper_add(encoder, &imx_ldb_encoder_helper_funcs);
 
-	if (imx_ldb_ch->bridge) {
-		ret = drm_bridge_attach(encoder, imx_ldb_ch->bridge, NULL, 0);
-		if (ret)
-			return ret;
-	} else {
-		/*
-		 * We want to add the connector whenever there is no bridge
-		 * that brings its own, not only when there is a panel. For
-		 * historical reasons, the ldb driver can also work without
-		 * a panel.
-		 */
-		drm_connector_helper_add(connector,
-					 &imx_ldb_connector_helper_funcs);
-		drm_connector_init(drm, connector,
-				   &imx_ldb_connector_funcs,
-				   DRM_MODE_CONNECTOR_LVDS);
-		drm_connector_attach_encoder(connector, encoder);
-	}
+	ret = drm_bridge_attach(encoder, imx_ldb_ch->bridge, NULL,
+				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+	if (ret)
+		return ret;
+
+	connector = drm_bridge_connector_init(drm, encoder);
+	if (IS_ERR(connector))
+		return PTR_ERR(connector);
+
+	drm_connector_attach_encoder(connector, encoder);
 
 	return 0;
 }
@@ -631,17 +582,7 @@ static int imx_ldb_probe(struct platform_device *pdev)
 			ret = PTR_ERR(channel->bridge);
 			if (ret != -ENODEV)
 				goto free_child;
-
 			channel->bridge = NULL;
-
-			ret = of_get_drm_display_mode(child,
-						      &channel->mode,
-						      &channel->bus_flags,
-						      OF_USE_NATIVE_MODE);
-			if (ret)
-				goto free_child;
-
-			channel->mode_valid = 1;
 		}
 
 		bus_format = of_get_bus_format(dev, child);
@@ -658,6 +599,20 @@ static int imx_ldb_probe(struct platform_device *pdev)
 			goto free_child;
 		}
 		channel->bus_format = bus_format;
+
+		/*
+		 * legacy bridge doesn't handle bus_format, so create it after
+		 * checking the bus_format property.
+		 */
+		if (!channel->bridge) {
+			channel->bridge = devm_imx_drm_legacy_bridge(dev, child,
+								     DRM_MODE_CONNECTOR_LVDS);
+			if (IS_ERR(channel->bridge)) {
+				ret = PTR_ERR(channel->bridge);
+				goto free_child;
+			}
+		}
+
 		channel->child = child;
 	}