From 00e4a73d6fa526945852d8278fadc163f260bbe9 Mon Sep 17 00:00:00 2001
From: Jagan Teki <jagan@amarulasolutions.com>
Date: Thu, 3 Mar 2022 22:06:51 +0530
Subject: exynos: drm: dsi: Attach in_bridge in MIC driver
Git-commit: dd8b6803bc4914cbcd15470eccc4b887fbaa7642
Patch-mainline: v5.19-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

MIC drivers in the Exynos5433 display pipeline are already registered
as bridge drivers and it is more advisable to attach the downstream
bridge on the bridge attach call instead of doing the same in the
DSI driver.

This makes bridge attachment more meaningful and avoids the races
during bridge function calls.

So, move the bridge finding and drm_bridge_attach from DSI to MIC.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220303163654.3381470-4-jagan@amarulasolutions.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/exynos/exynos_drm_dsi.c | 15 ---------------
 drivers/gpu/drm/exynos/exynos_drm_mic.c | 22 ++++++++++++++++++++++
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 334862d422e2..d995aab54731 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -1662,11 +1662,6 @@ static int exynos_dsi_of_read_u32(const struct device_node *np,
 	return ret;
 }
 
-enum {
-	DSI_PORT_IN,
-	DSI_PORT_OUT
-};
-
 static int exynos_dsi_parse_dt(struct exynos_dsi *dsi)
 {
 	struct device *dev = dsi->dev;
@@ -1697,8 +1692,6 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 	struct exynos_dsi *dsi = dev_get_drvdata(dev);
 	struct drm_encoder *encoder = &dsi->encoder;
 	struct drm_device *drm_dev = data;
-	struct device_node *in_bridge_node;
-	struct drm_bridge *in_bridge;
 	int ret;
 
 	drm_simple_encoder_init(drm_dev, encoder, DRM_MODE_ENCODER_TMDS);
@@ -1709,14 +1702,6 @@ static int exynos_dsi_bind(struct device *dev, struct device *master,
 	if (ret < 0)
 		return ret;
 
-	in_bridge_node = of_graph_get_remote_node(dev->of_node, DSI_PORT_IN, 0);
-	if (in_bridge_node) {
-		in_bridge = of_drm_find_bridge(in_bridge_node);
-		if (in_bridge)
-			drm_bridge_attach(encoder, in_bridge, NULL, 0);
-		of_node_put(in_bridge_node);
-	}
-
 	return mipi_dsi_host_register(&dsi->dsi_host);
 }
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_mic.c b/drivers/gpu/drm/exynos/exynos_drm_mic.c
index 32672bf8ae4a..9e06f8e2a863 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_mic.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_mic.c
@@ -102,6 +102,7 @@ struct exynos_mic {
 	struct videomode vm;
 	struct drm_encoder *encoder;
 	struct drm_bridge bridge;
+	struct drm_bridge *next_bridge;
 
 	bool enabled;
 };
@@ -298,12 +299,22 @@ static void mic_pre_enable(struct drm_bridge *bridge)
 
 static void mic_enable(struct drm_bridge *bridge) { }
 
+static int mic_attach(struct drm_bridge *bridge,
+		      enum drm_bridge_attach_flags flags)
+{
+	struct exynos_mic *mic = bridge->driver_private;
+
+	return drm_bridge_attach(bridge->encoder, mic->next_bridge,
+				 &mic->bridge, flags);
+}
+
 static const struct drm_bridge_funcs mic_bridge_funcs = {
 	.disable = mic_disable,
 	.post_disable = mic_post_disable,
 	.mode_set = mic_mode_set,
 	.pre_enable = mic_pre_enable,
 	.enable = mic_enable,
+	.attach = mic_attach,
 };
 
 static int exynos_mic_bind(struct device *dev, struct device *master,
@@ -377,6 +388,7 @@ static int exynos_mic_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct exynos_mic *mic;
+	struct device_node *remote;
 	struct resource res;
 	int ret, i;
 
@@ -420,6 +432,16 @@ static int exynos_mic_probe(struct platform_device *pdev)
 		}
 	}
 
+	remote = of_graph_get_remote_node(dev->of_node, 1, 0);
+	mic->next_bridge = of_drm_find_bridge(remote);
+	if (IS_ERR(mic->next_bridge)) {
+		DRM_DEV_ERROR(dev, "mic: Failed to find next bridge\n");
+		ret = PTR_ERR(mic->next_bridge);
+		goto err;
+	}
+
+	of_node_put(remote);
+
 	platform_set_drvdata(pdev, mic);
 
 	mic->bridge.funcs = &mic_bridge_funcs;
-- 
2.38.1