drm/panel: waveshare: Add automatic panel recognition for DSI panels

arch/arm/boot/dts/overlays/README

@@ -6069,6 +6069,8 @@ Params: 2_8_inch                2.8" 480x640
         11_9_inch               11.9" 320x1480
         13_3_inch_4lane         13.3" 1920x1080 4lane
         13_3_inch_2lane         13.3" 1920x1080 2lane
+        auto_rec                Automatic panel recognition (1200x1920 or
+                                1920x1200 at 30fps/60fps)
         i2c1                    Use i2c-1 with jumper wires from GPIOs 2&3
         disable_touch           Disable the touch controller
         rotation                Set the panel orientation property

arch/arm/boot/dts/overlays/vc4-kms-dsi-waveshare-panel-overlay.dts

@@ -136,6 +136,9 @@
 		7_0_inchH = <&panel>, "compatible=waveshare,7.0inch-h-panel",
 				  <&touch>, "touchscreen-swapped-x-y?",
 				  <&touch>, "touchscreen-inverted-x?";
+		auto_rec = <&panel>, "compatible=waveshare,automatic-recognition-panel",
+				  <&touch>, "touchscreen-swapped-x-y?",
+				  <&touch>, "touchscreen-inverted-x?";
 		i2c1 = <&i2c_frag>, "target:0=",<&i2c1>,
 		       <0>, "-3-4+5";
 		disable_touch = <&touch>, "status=disabled";

drivers/gpu/drm/panel/panel-waveshare-dsi.c

@@ -30,6 +30,7 @@ struct ws_panel {
 	struct i2c_client *i2c;
 	const struct drm_display_mode *mode;
 	enum drm_panel_orientation orientation;
+	int lanes;
 };
 
 struct ws_panel_data {
@@ -345,6 +346,63 @@ static const struct ws_panel_data ws_panel_7_0_h_data = {
 	.mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | MIPI_DSI_CLOCK_NON_CONTINUOUS,
 };
 
+/* 10.1inch DSI LCD (E)
+ * https://www.waveshare.com/10.1inch-dsi-lcd-e.htm
+ */
+static const struct drm_display_mode ws_panel_1200x1920_60fps_mode = {
+	.clock = 166666,
+	.hdisplay = 1200,
+	.hsync_start = 1200 + 28,
+	.hsync_end = 1200 + 28 + 10,
+	.htotal = 1200 + 28 + 10 + 30,
+	.vdisplay = 1920,
+	.vsync_start = 1920 + 238,
+	.vsync_end = 1920 + 238 + 4,
+	.vtotal = 1920 + 238 + 4 + 28,
+};
+
+static const struct drm_display_mode ws_panel_1200x1920_30fps_mode = {
+	.clock = 83333,
+	.hdisplay = 1200,
+	.hsync_start = 1200 + 28,
+	.hsync_end = 1200 + 28 + 10,
+	.htotal = 1200 + 28 + 10 + 30,
+	.vdisplay = 1920,
+	.vsync_start = 1920 + 238,
+	.vsync_end = 1920 + 238 + 4,
+	.vtotal = 1920 + 238 + 4 + 28,
+};
+
+static const struct drm_display_mode ws_panel_1920x1200_60fps_mode = {
+	.clock = 166666,
+	.hdisplay = 1920,
+	.hsync_start = 1920 + 238,
+	.hsync_end = 1920 + 238 + 4,
+	.htotal = 1920 + 238 + 4 + 28,
+	.vdisplay = 1200,
+	.vsync_start = 1200 + 28,
+	.vsync_end = 1200 + 28 + 10,
+	.vtotal = 1200 + 28 + 10 + 30,
+};
+
+static const struct drm_display_mode ws_panel_1920x1200_30fps_mode = {
+	.clock = 83333,
+	.hdisplay = 1920,
+	.hsync_start = 1920 + 238,
+	.hsync_end = 1920 + 238 + 4,
+	.htotal = 1920 + 238 + 4 + 28,
+	.vdisplay = 1200,
+	.vsync_start = 1200 + 28,
+	.vsync_end = 1200 + 28 + 10,
+	.vtotal = 1200 + 28 + 10 + 30,
+};
+
+static const struct ws_panel_data ws_panel_automatic_data = {
+	.mode = NULL,
+	.lanes = 0,
+	.mode_flags = MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO | MIPI_DSI_CLOCK_NON_CONTINUOUS,
+};
+
 static struct ws_panel *panel_to_ts(struct drm_panel *panel)
 {
 	return container_of(panel, struct ws_panel, base);
@@ -359,6 +417,68 @@ static void ws_panel_i2c_write(struct ws_panel *ts, u8 reg, u8 val)
 		dev_err(&ts->i2c->dev, "I2C write failed: %d\n", ret);
 }
 
+static int ws_panel_i2c_read(struct ws_panel *ts, u8 reg)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(ts->i2c, reg);
+	if (ret < 0)
+		dev_err(&ts->i2c->dev, "read reg 0x%02x failed %d\n", reg, ret);
+	return ret;
+}
+
+static int ws_panel_auto_detect(struct ws_panel *ts)
+{
+	int screen_type;
+	int rotate;
+	int fps;
+
+	fps = ws_panel_i2c_read(ts, 0xd0);
+	if (fps < 0)
+		return fps;
+
+	rotate = ws_panel_i2c_read(ts, 0xd1);
+	if (rotate < 0)
+		return rotate;
+
+	screen_type = ws_panel_i2c_read(ts, 0xd3);
+	if (screen_type < 0)
+		return screen_type;
+
+	dev_info(&ts->i2c->dev,
+		 "automatic panel detect screen_type=0x%x rotate=0x%x fps=0x%x\n",
+		 screen_type, rotate, fps);
+
+	if (screen_type == 0x01) {
+		switch (rotate) {
+		case 0:
+		case 2:
+			dev_info(&ts->i2c->dev, "select 1200x1920 panel\n");
+			ts->mode = fps == 60 ?
+			    &ws_panel_1200x1920_60fps_mode :
+			    &ws_panel_1200x1920_30fps_mode;
+			break;
+		case 1:
+		case 3:
+			dev_info(&ts->i2c->dev, "select 1920x1200 panel\n");
+			ts->mode = fps == 60 ?
+			    &ws_panel_1920x1200_60fps_mode :
+			    &ws_panel_1920x1200_30fps_mode;
+			break;
+		default:
+			dev_err(&ts->i2c->dev, "unknown rotate value %d\n", rotate);
+			return -EINVAL;
+		}
+		if (fps == 60)
+			ts->lanes = 4;
+		else
+			ts->lanes = 2;
+		return 0;
+	}
+	dev_err(&ts->i2c->dev, "unsupported panel D3=0x%x\n", screen_type);
+	return -EINVAL;
+}
+
 static int ws_panel_disable(struct drm_panel *panel)
 {
 	struct ws_panel *ts = panel_to_ts(panel);
@@ -492,13 +612,24 @@ static int ws_panel_probe(struct i2c_client *i2c)
 	if (!_ws_panel_data)
 		return -EINVAL;
 
-	ts->mode = _ws_panel_data->mode;
-	if (!ts->mode)
-		return -EINVAL;
-
+	ts->i2c = i2c;
 	i2c_set_clientdata(i2c, ts);
+	ts->lanes = _ws_panel_data->lanes;
+	/*
+	 * automatic recognition panel
+	 */
+	if (of_device_is_compatible(dev->of_node, "waveshare,automatic-recognition-panel")) {
+		ret = ws_panel_auto_detect(ts);
+		if (ret) {
+			dev_err(dev, "panel auto detect failed\n");
+			return ret;
+		}
+	} else {
+		ts->mode = _ws_panel_data->mode;
+	}
 
-	ts->i2c = i2c;
+	if (!ts->mode)
+		return -EINVAL;
 
 	ws_panel_i2c_write(ts, 0xc0, 0x01);
 	ws_panel_i2c_write(ts, 0xc2, 0x01);
@@ -556,7 +687,7 @@ static int ws_panel_probe(struct i2c_client *i2c)
 
 	ts->dsi->mode_flags = _ws_panel_data->mode_flags;
 	ts->dsi->format = MIPI_DSI_FMT_RGB888;
-	ts->dsi->lanes = _ws_panel_data->lanes;
+	ts->dsi->lanes = ts->lanes;
 
 	ret = devm_mipi_dsi_attach(dev, ts->dsi);
 
@@ -583,6 +714,7 @@ static void ws_panel_shutdown(struct i2c_client *i2c)
 {
 	struct ws_panel *ts = i2c_get_clientdata(i2c);
 
+	ws_panel_i2c_write(ts, 0xd2, 0x5a);
 	ws_panel_disable(&ts->base);
 }
 
@@ -635,6 +767,9 @@ static const struct of_device_id ws_panel_of_ids[] = {
 	}, {
 		.compatible = "waveshare,7.0inch-h-panel",
 		.data = &ws_panel_7_0_h_data,
+	}, {
+		.compatible = "waveshare,automatic-recognition-panel",
+		.data = &ws_panel_automatic_data,
 	}, {
 		/* sentinel */
 	}