Waveshare dsi (#5)

* drm/panel: waveshare: Add automatic panel detection support

Add support for Waveshare automatic detection DSI panels which
identify themselves at runtime via I2C registers. The driver reads
screen type, rotation and refresh rate from registers 0xd0-0xd3
to select the appropriate display mode and DSI lane configuration.

Supported configurations include 1200x1920 and 1920x1200 panels
at both 30fps (2 lanes) and 60fps (4 lanes) refresh rates.

Signed-off-by: Goodwill <646689853@qq.com>

* ARM: dts: overlays: waveshare-dsi: Add auto_detect panel option

Add the auto_detect overlay parameter to select the automatic detection
panel compatible string (waveshare,automatic-detection-panel). This
enables runtime panel detection via I2C for Waveshare DSI displays
that support automatic identification.

Signed-off-by: Goodwill <646689853@qq.com>

---------

Signed-off-by: Goodwill <646689853@qq.com>

Author: EngineerWill

arch/arm/boot/dts/overlays/README

@@ -6069,7 +6069,7 @@ 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
+        auto_detect             Automatic panel detection (1200x1920 or
                                 1920x1200 at 30fps/60fps)
         i2c1                    Use i2c-1 with jumper wires from GPIOs 2&3
         disable_touch           Disable the touch controller

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

@@ -136,7 +136,7 @@
 		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",
+		auto_detect = <&panel>, "compatible=waveshare,automatic-detection-panel",
 				  <&touch>, "touchscreen-swapped-x-y?",
 				  <&touch>, "touchscreen-inverted-x?";
 		i2c1 = <&i2c_frag>, "target:0=",<&i2c1>,

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

@@ -615,10 +615,9 @@ static int ws_panel_probe(struct i2c_client *i2c)
 	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")) {
+
+	/* For automatic detection panels, mode is NULL - detect via I2C */
+	if (!_ws_panel_data->mode) {
 		ret = ws_panel_auto_detect(ts);
 		if (ret) {
 			dev_err(dev, "panel auto detect failed\n");
@@ -701,10 +700,18 @@ static int ws_panel_probe(struct i2c_client *i2c)
 	return -ENODEV;
 }
 
+static void ws_panel_reset(struct drm_panel *panel)
+{
+	struct ws_panel *ts = panel_to_ts(panel);
+
+	ws_panel_i2c_write(ts, 0xd2, 0x5a);
+}
+
 static void ws_panel_remove(struct i2c_client *i2c)
 {
 	struct ws_panel *ts = i2c_get_clientdata(i2c);
 
+	ws_panel_reset(&ts->base);
 	ws_panel_disable(&ts->base);
 
 	drm_panel_remove(&ts->base);
@@ -714,7 +721,7 @@ 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_reset(&ts->base);
 	ws_panel_disable(&ts->base);
 }
 
@@ -768,7 +775,7 @@ 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",
+		.compatible = "waveshare,automatic-detection-panel",
 		.data = &ws_panel_automatic_data,
 	}, {
 		/* sentinel */