kernel-5.15/0615-baikal_vdu-et101-display-port-support.patch

From 4dbd82fde8dde03d7921d630ceecd74bdda62692 Mon Sep 17 00:00:00 2001
From: Alexey Sheplyakov <asheplyakov@altlinux.org>
Date: Thu, 10 Mar 2022 04:33:35 +0400
Subject: [PATCH 615/634] baikal_vdu: et101 display port support

LVDS is connected via a bridge on et101, and current code
(baikal_vdu_crtc_helper_mode_set_nofb, baikal_vdu_crtc_helper_enable)
assumes that LVDS is connected directly to a panel. To solve
the problem

- check for output type instead of checking for panel
- adjust hsync/vsync parameters calculation (in baikal_vdu_crtc_helper_mode_set_nofb)

Note: due to hardware peculiarities using HDMI and DP is possible
only with some constraints:

- Resolution of both displays should be exactly the same
- HDMI viewport must be above or below the display port one
---
 drivers/gpu/drm/baikal/baikal_vdu_crtc.c | 32 +++++++++++++++---------
 drivers/gpu/drm/baikal/baikal_vdu_drv.c  |  5 ++--
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/baikal/baikal_vdu_crtc.c b/drivers/gpu/drm/baikal/baikal_vdu_crtc.c
index 039150c59..e338ff8b3 100644
--- a/drivers/gpu/drm/baikal/baikal_vdu_crtc.c
+++ b/drivers/gpu/drm/baikal/baikal_vdu_crtc.c
@@ -134,14 +134,15 @@ static void baikal_vdu_crtc_helper_mode_set_nofb(struct drm_crtc *crtc)
 	drm_mode_debug_printmodeline(mode);
 
 	ppl = mode->hdisplay / 16;
-	if (priv->panel) {
+	if (priv->type == VDU_TYPE_LVDS) {
 		hsw = mode->hsync_end - mode->hsync_start;
 		hfp = mode->hsync_start - mode->hdisplay - 1;
+		hbp = mode->htotal - mode->hsync_end;
 	} else {
 		hsw = mode->hsync_end - mode->hsync_start - 1;
 		hfp = mode->hsync_start - mode->hdisplay;
+		hbp = mode->htotal - mode->hsync_end - 1;
 	}
-	hbp = mode->htotal - mode->hsync_end;
 
 	lpp = mode->vdisplay;
 	vsw = mode->vsync_end - mode->vsync_start;
@@ -194,13 +195,13 @@ static void baikal_vdu_crtc_helper_enable(struct drm_crtc *crtc,
 {
 	struct baikal_vdu_private *priv = crtc->dev->dev_private;
 	struct drm_panel *panel = priv->panel;
-	struct device_node *panel_node;
-	const char *data_mapping;
+	const char *data_mapping = NULL;
 	u32 cntl, gpio;
 
+	DRM_DEV_DEBUG_DRIVER(crtc->dev->dev, "priv = %px\n", priv);
 	DRM_DEV_DEBUG_DRIVER(crtc->dev->dev, "enabling pixel clock\n");
 	clk_prepare_enable(priv->clk);
-
+	DRM_DEV_DEBUG_DRIVER(crtc->dev->dev, "panel = %px\n", panel);
 	drm_panel_prepare(panel);
 
 	writel(ISCR_VSC_VFP, priv->regs + ISCR);
@@ -217,17 +218,24 @@ static void baikal_vdu_crtc_helper_enable(struct drm_crtc *crtc,
 	cntl |= CR1_LCE + CR1_FDW_16_WORDS;
 
 	if (priv->type == VDU_TYPE_LVDS) {
-		panel_node = panel->dev->of_node;
-		if (of_property_read_string(panel_node, "data-mapping", &data_mapping)) {
+		if (panel) {
+			of_property_read_string(panel->dev->of_node,
+						"data-mapping", &data_mapping);
+		}
+		if (!data_mapping) {
 			cntl |= CR1_OPS_LCD18;
-		} else if (strncmp(data_mapping, "vesa-24", 7))
+			dev_dbg(crtc->dev->dev, "data mapping not specified, using jeida-18");
+		} else if (!strncmp(data_mapping, "vesa-24", 7)) {
 			cntl |= CR1_OPS_LCD24;
-		else if (strncmp(data_mapping, "jeida-18", 8))
-			cntl |= CR1_OPS_LCD18;
-		else {
-			dev_warn(crtc->dev->dev, "%s data mapping is not supported, vesa-24 is set\n", data_mapping);
+			dev_dbg(crtc->dev->dev, "using vesa-24 mapping\n");
+		} else if (!strncmp(data_mapping, "jeida-18", 8)) {
+				cntl |= CR1_OPS_LCD18;
+				dev_dbg(crtc->dev->dev, "using jeida-18 mapping\n");
+		} else {
+			dev_warn(crtc->dev->dev, "unsupported data mapping '%s', using vesa-24\n", data_mapping);
 			cntl |= CR1_OPS_LCD24;
 		}
+
 		gpio = GPIOR_UHD_ENB;
 		if (priv->ep_count == 4)
 			gpio |= GPIOR_UHD_QUAD_PORT;
diff --git a/drivers/gpu/drm/baikal/baikal_vdu_drv.c b/drivers/gpu/drm/baikal/baikal_vdu_drv.c
index af0e0ca19..cedf7962d 100644
--- a/drivers/gpu/drm/baikal/baikal_vdu_drv.c
+++ b/drivers/gpu/drm/baikal/baikal_vdu_drv.c
@@ -95,9 +95,9 @@ static int vdu_modeset_init(struct drm_device *dev)
 	mode_config = &dev->mode_config;
 	mode_config->funcs = &mode_config_funcs;
 	mode_config->min_width = 1;
-	mode_config->max_width = 4096;
+	mode_config->max_width = 4095;
 	mode_config->min_height = 1;
-	mode_config->max_height = 4096;
+	mode_config->max_height = 4095;
 
 	ret = baikal_vdu_primary_plane_init(dev);
 	if (ret != 0) {
@@ -124,6 +124,7 @@ static int vdu_modeset_init(struct drm_device *dev)
 		goto out_config;
 	}
 	priv->ep_count = ep_count;
+	dev_dbg(dev->dev, "panel/bridge has %d endpoints\n", priv->ep_count);
 
 	if (priv->bridge) {
 		struct drm_encoder *encoder = &priv->encoder;
-- 
2.33.2