path: root/target/linux/bcm27xx/patches-5.15/950-0715-drm-vc4-Convert-vc4_dsi-to-using-a-bridge-instead-of.patch

From 3e6793632310f9991b75c3095a9795b6a8d1d859 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.com>
Date: Wed, 15 Dec 2021 17:57:45 +0000
Subject: [PATCH] drm/vc4: Convert vc4_dsi to using a bridge instead of
 encoder.

Remove the encoder functions, and create a bridge attached to
this dumb encoder which implements the same functionality.

As a bridge has state which an encoder doesn't, we need to
add the state management functions as well.

As there is no bridge atomic_mode_set, move the initialisation
code that was in mode_set into _pre_enable.
The code to actually enable and disable sending video are split
from the general control into _enable and _disable.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
---
 drivers/gpu/drm/vc4/vc4_dsi.c | 124 ++++++++++++++++++++++++----------
 1 file changed, 90 insertions(+), 34 deletions(-)

--- a/drivers/gpu/drm/vc4/vc4_dsi.c
+++ b/drivers/gpu/drm/vc4/vc4_dsi.c
@@ -554,6 +554,7 @@ struct vc4_dsi {
 	struct mipi_dsi_host dsi_host;
 	struct drm_encoder *encoder;
 	struct drm_bridge *out_bridge;
+	struct drm_bridge bridge;
 
 	void __iomem *regs;
 
@@ -655,6 +656,12 @@ to_vc4_dsi_encoder(struct drm_encoder *e
 	return container_of(encoder, struct vc4_dsi_encoder, base.base);
 }
 
+static inline struct vc4_dsi *
+bridge_to_vc4_dsi(struct drm_bridge *bridge)
+{
+	return container_of(bridge, struct vc4_dsi, bridge);
+}
+
 static const struct debugfs_reg32 dsi0_regs[] = {
 	VC4_REG32(DSI0_CTRL),
 	VC4_REG32(DSI0_STAT),
@@ -792,11 +799,21 @@ dsi_esc_timing(u32 ns)
 	return DIV_ROUND_UP(ns, ESC_TIME_NS);
 }
 
-static void vc4_dsi_encoder_disable(struct drm_encoder *encoder,
-				    struct drm_atomic_state *state)
+static void vc4_dsi_bridge_disable(struct drm_bridge *bridge,
+				   struct drm_bridge_state *state)
+{
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+	u32 disp0_ctrl;
+
+	disp0_ctrl = DSI_PORT_READ(DISP0_CTRL);
+	disp0_ctrl &= ~DSI_DISP0_ENABLE;
+	DSI_PORT_WRITE(DISP0_CTRL, disp0_ctrl);
+}
+
+static void vc4_dsi_bridge_post_disable(struct drm_bridge *bridge,
+					struct drm_bridge_state *state)
 {
-	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
-	struct vc4_dsi *dsi = vc4_encoder->dsi;
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
 	struct device *dev = &dsi->pdev->dev;
 
 	vc4_dsi_ulps(dsi, true);
@@ -821,12 +838,11 @@ static void vc4_dsi_encoder_disable(stru
  * higher-than-expected clock rate to the panel, but that's what the
  * firmware does too.
  */
-static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
+static bool vc4_dsi_bridge_mode_fixup(struct drm_bridge *bridge,
+				      const struct drm_display_mode *mode,
+				      struct drm_display_mode *adjusted_mode)
 {
-	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
-	struct vc4_dsi *dsi = vc4_encoder->dsi;
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
 	struct clk *phy_parent = clk_get_parent(dsi->pll_phy_clock);
 	unsigned long parent_rate = clk_get_rate(phy_parent);
 	unsigned long pixel_clock_hz = mode->clock * 1000;
@@ -858,16 +874,18 @@ static bool vc4_dsi_encoder_mode_fixup(s
 	return true;
 }
 
-static void vc4_dsi_encoder_mode_set(struct drm_encoder *encoder,
-				     struct drm_crtc_state *crtc_state,
-				     struct drm_connector_state *conn_state)
+static void vc4_dsi_bridge_pre_enable(struct drm_bridge *bridge,
+				      struct drm_bridge_state *old_state)
 {
-	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
-	struct vc4_dsi *dsi = vc4_encoder->dsi;
+	struct drm_atomic_state *state = old_state->base.state;
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+	const struct drm_crtc_state *crtc_state;
 	struct device *dev = &dsi->pdev->dev;
 	const struct drm_display_mode *mode;
+	struct drm_connector *connector;
 	bool debug_dump_regs = false;
 	unsigned long hs_clock;
+	struct drm_crtc *crtc;
 	u32 ui_ns;
 	/* Minimum LP state duration in escape clock cycles. */
 	u32 lpx = dsi_esc_timing(60);
@@ -888,6 +906,14 @@ static void vc4_dsi_encoder_mode_set(str
 		drm_print_regset32(&p, &dsi->regset);
 	}
 
+	/*
+	 * Retrieve the CRTC adjusted mode. This requires a little dance to go
+	 * from the bridge to the encoder, to the connector and to the CRTC.
+	 */
+	connector = drm_atomic_get_new_connector_for_encoder(state,
+							     bridge->encoder);
+	crtc = drm_atomic_get_new_connector_state(state, connector)->crtc;
+	crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 	mode = &crtc_state->adjusted_mode;
 
 	pixel_clock_hz = mode->clock * 1000;
@@ -1102,14 +1128,6 @@ static void vc4_dsi_encoder_mode_set(str
 		       ~DSI_PORT_BIT(PHY_AFEC0_RESET));
 
 	vc4_dsi_ulps(dsi, false);
-}
-
-static void vc4_dsi_encoder_enable(struct drm_encoder *encoder,
-				   struct drm_atomic_state *state)
-{
-	struct vc4_dsi_encoder *vc4_encoder = to_vc4_dsi_encoder(encoder);
-	struct vc4_dsi *dsi = vc4_encoder->dsi;
-	bool debug_dump_regs = false;
 
 	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
 		DSI_PORT_WRITE(DISP0_CTRL,
@@ -1118,13 +1136,23 @@ static void vc4_dsi_encoder_enable(struc
 			       VC4_SET_FIELD(dsi->format, DSI_DISP0_PFORMAT) |
 			       VC4_SET_FIELD(DSI_DISP0_LP_STOP_PERFRAME,
 					     DSI_DISP0_LP_STOP_CTRL) |
-			       DSI_DISP0_ST_END |
-			       DSI_DISP0_ENABLE);
+			       DSI_DISP0_ST_END);
 	} else {
 		DSI_PORT_WRITE(DISP0_CTRL,
-			       DSI_DISP0_COMMAND_MODE |
-			       DSI_DISP0_ENABLE);
+			       DSI_DISP0_COMMAND_MODE);
 	}
+}
+
+static void vc4_dsi_bridge_enable(struct drm_bridge *bridge,
+				  struct drm_bridge_state *old_state)
+{
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+	bool debug_dump_regs = false;
+	u32 disp0_ctrl;
+
+	disp0_ctrl = DSI_PORT_READ(DISP0_CTRL);
+	disp0_ctrl |= DSI_DISP0_ENABLE;
+	DSI_PORT_WRITE(DISP0_CTRL, disp0_ctrl);
 
 	if (debug_dump_regs) {
 		struct drm_printer p = drm_info_printer(&dsi->pdev->dev);
@@ -1133,6 +1161,16 @@ static void vc4_dsi_encoder_enable(struc
 	}
 }
 
+static int vc4_dsi_bridge_attach(struct drm_bridge *bridge,
+				 enum drm_bridge_attach_flags flags)
+{
+	struct vc4_dsi *dsi = bridge_to_vc4_dsi(bridge);
+
+	/* Attach the panel or bridge to the dsi bridge */
+	return drm_bridge_attach(bridge->encoder, dsi->out_bridge,
+				 &dsi->bridge, flags);
+}
+
 static ssize_t vc4_dsi_host_transfer(struct mipi_dsi_host *host,
 				     const struct mipi_dsi_msg *msg)
 {
@@ -1309,6 +1347,7 @@ static int vc4_dsi_host_attach(struct mi
 			       struct mipi_dsi_device *device)
 {
 	struct vc4_dsi *dsi = host_to_dsi(host);
+	int ret;
 
 	dsi->lanes = device->lanes;
 	dsi->channel = device->channel;
@@ -1343,7 +1382,15 @@ static int vc4_dsi_host_attach(struct mi
 		return 0;
 	}
 
-	return component_add(&dsi->pdev->dev, &vc4_dsi_ops);
+	drm_bridge_add(&dsi->bridge);
+
+	ret = component_add(&dsi->pdev->dev, &vc4_dsi_ops);
+	if (ret) {
+		drm_bridge_remove(&dsi->bridge);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int vc4_dsi_host_detach(struct mipi_dsi_host *host,
@@ -1352,6 +1399,7 @@ static int vc4_dsi_host_detach(struct mi
 	struct vc4_dsi *dsi = host_to_dsi(host);
 
 	component_del(&dsi->pdev->dev, &vc4_dsi_ops);
+	drm_bridge_remove(&dsi->bridge);
 	return 0;
 }
 
@@ -1361,11 +1409,16 @@ static const struct mipi_dsi_host_ops vc
 	.transfer = vc4_dsi_host_transfer,
 };
 
-static const struct drm_encoder_helper_funcs vc4_dsi_encoder_helper_funcs = {
-	.atomic_disable = vc4_dsi_encoder_disable,
-	.atomic_enable = vc4_dsi_encoder_enable,
-	.mode_fixup = vc4_dsi_encoder_mode_fixup,
-	.atomic_mode_set = vc4_dsi_encoder_mode_set,
+static const struct drm_bridge_funcs vc4_dsi_bridge_funcs = {
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_pre_enable = vc4_dsi_bridge_pre_enable,
+	.atomic_enable = vc4_dsi_bridge_enable,
+	.atomic_disable = vc4_dsi_bridge_disable,
+	.atomic_post_disable = vc4_dsi_bridge_post_disable,
+	.attach = vc4_dsi_bridge_attach,
+	.mode_fixup = vc4_dsi_bridge_mode_fixup,
 };
 
 static const struct vc4_dsi_variant bcm2711_dsi1_variant = {
@@ -1692,9 +1745,8 @@ static int vc4_dsi_bind(struct device *d
 		return ret;
 
 	drm_simple_encoder_init(drm, dsi->encoder, DRM_MODE_ENCODER_DSI);
-	drm_encoder_helper_add(dsi->encoder, &vc4_dsi_encoder_helper_funcs);
 
-	ret = drm_bridge_attach(dsi->encoder, dsi->out_bridge, NULL, 0);
+	ret = drm_bridge_attach(dsi->encoder, &dsi->bridge, NULL, 0);
 	if (ret)
 		return ret;
 
@@ -1730,6 +1782,10 @@ static int vc4_dsi_dev_probe(struct plat
 		return -ENOMEM;
 	dev_set_drvdata(dev, dsi);
 
+	dsi->bridge.funcs = &vc4_dsi_bridge_funcs;
+	dsi->bridge.of_node = dev->of_node;
+	dsi->bridge.type = DRM_MODE_CONNECTOR_DSI;
+
 	dsi->pdev = pdev;
 	dsi->dsi_host.ops = &vc4_dsi_host_ops;
 	dsi->dsi_host.dev = dev;