[RFC PATCH 2/2] drm/msm/mdp4: switch LVDS to use drm_bridge/_connector

[Dmitry Baryshkov <dmitry.baryshkov@linaro.org>]

LVDS support in MDP4 driver makes use of drm_connector directly. However
LCDC encoder and LVDS connector are wrappers around drm_panel. Switch
them to use drm_panel_bridge/drm_bridge_connector. This allows using
standard interface for the drm_panel and also inserting additional
bridges between encoder and panel.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/Makefile                  |   1 -
 drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c      |  32 ++++--
 drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h      |   6 +-
 .../gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c |  20 +---
 .../drm/msm/disp/mdp4/mdp4_lvds_connector.c   | 100 ------------------
 5 files changed, 28 insertions(+), 131 deletions(-)
 delete mode 100644 drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c

diff --git a/drivers/gpu/drm/msm/Makefile b/drivers/gpu/drm/msm/Makefile
index 66395ee0862a..709952c998e0 100644
--- a/drivers/gpu/drm/msm/Makefile
+++ b/drivers/gpu/drm/msm/Makefile
@@ -35,7 +35,6 @@ msm-$(CONFIG_DRM_MSM_MDP4) += \
 	disp/mdp4/mdp4_dsi_encoder.o \
 	disp/mdp4/mdp4_dtv_encoder.o \
 	disp/mdp4/mdp4_lcdc_encoder.o \
-	disp/mdp4/mdp4_lvds_connector.o \
 	disp/mdp4/mdp4_lvds_pll.o \
 	disp/mdp4/mdp4_irq.o \
 	disp/mdp4/mdp4_kms.o \
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
index fb48c8c19ec3..77ef3114a919 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c
@@ -6,6 +6,8 @@
 
 #include <linux/delay.h>
 
+#include <drm/drm_bridge.h>
+#include <drm/drm_bridge_connector.h>
 #include <drm/drm_vblank.h>
 
 #include "msm_drv.h"
@@ -199,7 +201,7 @@ static int mdp4_modeset_init_intf(struct mdp4_kms *mdp4_kms,
 	struct msm_drm_private *priv = dev->dev_private;
 	struct drm_encoder *encoder;
 	struct drm_connector *connector;
-	struct device_node *panel_node;
+	struct drm_bridge *next_bridge;
 	int dsi_id;
 	int ret;
 
@@ -209,11 +211,15 @@ static int mdp4_modeset_init_intf(struct mdp4_kms *mdp4_kms,
 		 * bail out early if there is no panel node (no need to
 		 * initialize LCDC encoder and LVDS connector)
 		 */
-		panel_node = of_graph_get_remote_node(dev->dev->of_node, 0, 0);
-		if (!panel_node)
-			return 0;
+		next_bridge = devm_drm_of_get_bridge(dev->dev, dev->dev->of_node, 0, 0);
+		if (IS_ERR(next_bridge)) {
+			ret = PTR_ERR(next_bridge);
+			if (ret == -ENODEV)
+				return 0;
+			return ret;
+		}
 
-		encoder = mdp4_lcdc_encoder_init(dev, panel_node);
+		encoder = mdp4_lcdc_encoder_init(dev);
 		if (IS_ERR(encoder)) {
 			DRM_DEV_ERROR(dev->dev, "failed to construct LCDC encoder\n");
 			return PTR_ERR(encoder);
@@ -222,12 +228,26 @@ static int mdp4_modeset_init_intf(struct mdp4_kms *mdp4_kms,
 		/* LCDC can be hooked to DMA_P (TODO: Add DMA_S later?) */
 		encoder->possible_crtcs = 1 << DMA_P;
 
-		connector = mdp4_lvds_connector_init(dev, panel_node, encoder);
+		ret = drm_bridge_attach(encoder, next_bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
+		if (ret) {
+			DRM_DEV_ERROR(dev->dev, "failed to attach LVDS panel/bridge: %d\n", ret);
+
+			return ret;
+		}
+
+		connector = drm_bridge_connector_init(dev, encoder);
 		if (IS_ERR(connector)) {
 			DRM_DEV_ERROR(dev->dev, "failed to initialize LVDS connector\n");
 			return PTR_ERR(connector);
 		}
 
+		ret = drm_connector_attach_encoder(connector, encoder);
+		if (ret) {
+			DRM_DEV_ERROR(dev->dev, "failed to attach LVDS connector: %d\n", ret);
+
+			return ret;
+		}
+
 		break;
 	case DRM_MODE_ENCODER_TMDS:
 		encoder = mdp4_dtv_encoder_init(dev);
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
index d27fa761bfc2..7535dc343b64 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.h
@@ -197,11 +197,7 @@ struct drm_crtc *mdp4_crtc_init(struct drm_device *dev,
 long mdp4_dtv_round_pixclk(struct drm_encoder *encoder, unsigned long rate);
 struct drm_encoder *mdp4_dtv_encoder_init(struct drm_device *dev);
 
-struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev,
-		struct device_node *panel_node);
-
-struct drm_connector *mdp4_lvds_connector_init(struct drm_device *dev,
-		struct device_node *panel_node, struct drm_encoder *encoder);
+struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev);
 
 #ifdef CONFIG_DRM_MSM_DSI
 struct drm_encoder *mdp4_dsi_encoder_init(struct drm_device *dev);
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
index 341dcd5087da..46d901fa0da0 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
@@ -14,7 +14,6 @@
 
 struct mdp4_lcdc_encoder {
 	struct drm_encoder base;
-	struct device_node *panel_node;
 	struct drm_panel *panel;
 	struct clk *lcdc_clk;
 	unsigned long int pixclock;
@@ -275,7 +274,6 @@ static void mdp4_lcdc_encoder_disable(struct drm_encoder *encoder)
 	struct mdp4_lcdc_encoder *mdp4_lcdc_encoder =
 			to_mdp4_lcdc_encoder(encoder);
 	struct mdp4_kms *mdp4_kms = get_kms(encoder);
-	struct drm_panel *panel;
 	int i, ret;
 
 	if (WARN_ON(!mdp4_lcdc_encoder->enabled))
@@ -283,12 +281,6 @@ static void mdp4_lcdc_encoder_disable(struct drm_encoder *encoder)
 
 	mdp4_write(mdp4_kms, REG_MDP4_LCDC_ENABLE, 0);
 
-	panel = of_drm_find_panel(mdp4_lcdc_encoder->panel_node);
-	if (!IS_ERR(panel)) {
-		drm_panel_disable(panel);
-		drm_panel_unprepare(panel);
-	}
-
 	/*
 	 * Wait for a vsync so we know the ENABLE=0 latched before
 	 * the (connector) source of the vsync's gets disabled,
@@ -317,7 +309,6 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder)
 			to_mdp4_lcdc_encoder(encoder);
 	unsigned long pc = mdp4_lcdc_encoder->pixclock;
 	struct mdp4_kms *mdp4_kms = get_kms(encoder);
-	struct drm_panel *panel;
 	uint32_t config;
 	int i, ret;
 
@@ -353,12 +344,6 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder)
 	if (ret)
 		DRM_DEV_ERROR(dev->dev, "failed to enable lcdc_clk: %d\n", ret);
 
-	panel = of_drm_find_panel(mdp4_lcdc_encoder->panel_node);
-	if (!IS_ERR(panel)) {
-		drm_panel_prepare(panel);
-		drm_panel_enable(panel);
-	}
-
 	setup_phy(encoder);
 
 	mdp4_write(mdp4_kms, REG_MDP4_LCDC_ENABLE, 1);
@@ -392,8 +377,7 @@ static const struct drm_encoder_helper_funcs mdp4_lcdc_encoder_helper_funcs = {
 };
 
 /* initialize encoder */
-struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev,
-		struct device_node *panel_node)
+struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev)
 {
 	struct drm_encoder *encoder = NULL;
 	struct mdp4_lcdc_encoder *mdp4_lcdc_encoder;
@@ -406,8 +390,6 @@ struct drm_encoder *mdp4_lcdc_encoder_init(struct drm_device *dev,
 		goto fail;
 	}
 
-	mdp4_lcdc_encoder->panel_node = panel_node;
-
 	encoder = &mdp4_lcdc_encoder->base;
 
 	drm_encoder_init(dev, encoder, &mdp4_lcdc_encoder_funcs,
diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
deleted file mode 100644
index 4755eb13ef79..000000000000
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c
+++ /dev/null
@@ -1,100 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) 2014 Red Hat
- * Author: Rob Clark <robdclark@gmail.com>
- * Author: Vinay Simha <vinaysimha@inforcecomputing.com>
- */
-
-#include "mdp4_kms.h"
-
-struct mdp4_lvds_connector {
-	struct drm_connector base;
-	struct drm_encoder *encoder;
-	struct device_node *panel_node;
-	struct drm_panel *panel;
-};
-#define to_mdp4_lvds_connector(x) container_of(x, struct mdp4_lvds_connector, base)
-
-static enum drm_connector_status mdp4_lvds_connector_detect(
-		struct drm_connector *connector, bool force)
-{
-	struct mdp4_lvds_connector *mdp4_lvds_connector =
-			to_mdp4_lvds_connector(connector);
-
-	if (!mdp4_lvds_connector->panel) {
-		mdp4_lvds_connector->panel =
-			of_drm_find_panel(mdp4_lvds_connector->panel_node);
-		if (IS_ERR(mdp4_lvds_connector->panel))
-			mdp4_lvds_connector->panel = NULL;
-	}
-
-	return mdp4_lvds_connector->panel ?
-			connector_status_connected :
-			connector_status_disconnected;
-}
-
-static void mdp4_lvds_connector_destroy(struct drm_connector *connector)
-{
-	struct mdp4_lvds_connector *mdp4_lvds_connector =
-			to_mdp4_lvds_connector(connector);
-
-	drm_connector_cleanup(connector);
-
-	kfree(mdp4_lvds_connector);
-}
-
-static int mdp4_lvds_connector_get_modes(struct drm_connector *connector)
-{
-	struct mdp4_lvds_connector *mdp4_lvds_connector =
-			to_mdp4_lvds_connector(connector);
-	struct drm_panel *panel = mdp4_lvds_connector->panel;
-	int ret = 0;
-
-	if (panel)
-		ret = drm_panel_get_modes(panel, connector);
-
-	return ret;
-}
-
-static const struct drm_connector_funcs mdp4_lvds_connector_funcs = {
-	.detect = mdp4_lvds_connector_detect,
-	.fill_modes = drm_helper_probe_single_connector_modes,
-	.destroy = mdp4_lvds_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 mdp4_lvds_connector_helper_funcs = {
-	.get_modes = mdp4_lvds_connector_get_modes,
-};
-
-/* initialize connector */
-struct drm_connector *mdp4_lvds_connector_init(struct drm_device *dev,
-		struct device_node *panel_node, struct drm_encoder *encoder)
-{
-	struct drm_connector *connector = NULL;
-	struct mdp4_lvds_connector *mdp4_lvds_connector;
-
-	mdp4_lvds_connector = kzalloc(sizeof(*mdp4_lvds_connector), GFP_KERNEL);
-	if (!mdp4_lvds_connector)
-		return ERR_PTR(-ENOMEM);
-
-	mdp4_lvds_connector->encoder = encoder;
-	mdp4_lvds_connector->panel_node = panel_node;
-
-	connector = &mdp4_lvds_connector->base;
-
-	drm_connector_init(dev, connector, &mdp4_lvds_connector_funcs,
-			DRM_MODE_CONNECTOR_LVDS);
-	drm_connector_helper_add(connector, &mdp4_lvds_connector_helper_funcs);
-
-	connector->polled = 0;
-
-	connector->interlace_allowed = 0;
-	connector->doublescan_allowed = 0;
-
-	drm_connector_attach_encoder(connector, encoder);
-
-	return connector;
-}
-- 
2.35.1