test: dm: add video bridge tests

Add tests for video bridge ops.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/sandbox/dts/test.dts

@@ -1047,6 +1047,31 @@
 		};
 	};
 
+	lvds-encoder {
+		compatible = "lvds-encoder";
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+
+				bridge_input: endpoint {
+					/* link to output */
+				};
+			};
+
+			port@1 {
+				reg = <1>;
+
+				bridge_output: endpoint {
+					remote-endpoint = <&panel_input>;
+				};
+			};
+		};
+	};
+
 	wdt-gpio-toggle {
 		gpios = <&gpio_a 8 0>;
 		compatible = "linux,wdt-gpio";
@@ -1402,6 +1427,27 @@
 	panel {
 		compatible = "simple-panel";
 		backlight = <&backlight 0 100>;
+
+		display-timings {
+			timing@0 {
+				/* 1280x800@60Hz */
+				clock-frequency = <68000000>;
+				hactive = <1280>;
+				hfront-porch = <48>;
+				hback-porch = <18>;
+				hsync-len = <30>;
+				vactive = <800>;
+				vfront-porch = <3>;
+				vback-porch = <12>;
+				vsync-len = <5>;
+			};
+		};
+
+		port {
+			panel_input: endpoint {
+				remote-endpoint = <&bridge_output>;
+			};
+		};
 	};
 
 	scsi {

configs/sandbox_defconfig

@@ -328,6 +328,8 @@ CONFIG_USB_ETH_CDC=y
 CONFIG_VIDEO=y
 CONFIG_VIDEO_FONT_SUN12X22=y
 CONFIG_VIDEO_COPY=y
+CONFIG_VIDEO_BRIDGE=y
+CONFIG_VIDEO_BRIDGE_LVDS_CODEC=y
 CONFIG_CONSOLE_ROTATION=y
 CONFIG_CONSOLE_TRUETYPE=y
 CONFIG_CONSOLE_TRUETYPE_CANTORAONE=y

test/dm/Makefile

@@ -63,6 +63,7 @@ obj-$(CONFIG_SOUND) += i2s.o
 obj-$(CONFIG_CLK_K210_SET_RATE) += k210_pll.o
 obj-$(CONFIG_IOMMU) += iommu.o
 obj-$(CONFIG_LED) += led.o
+obj-$(CONFIG_VIDEO_BRIDGE_LVDS_CODEC) += video_bridge.o
 obj-$(CONFIG_DM_MAILBOX) += mailbox.o
 obj-$(CONFIG_DM_MDIO) += mdio.o
 obj-$(CONFIG_DM_MDIO_MUX) += mdio_mux.o

test/dm/video_bridge.c

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for video bridge uclass
+ *
+ * Copyright (c) 2025 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <backlight.h>
+#include <dm.h>
+#include <panel.h>
+#include <video.h>
+#include <video_bridge.h>
+#include <asm/gpio.h>
+#include <asm/test.h>
+#include <dm/test.h>
+#include <power/regulator.h>
+#include <test/test.h>
+#include <test/ut.h>
+
+/* Basic test of the video uclass, test is based on driven panel */
+static int dm_test_video_bridge(struct unit_test_state *uts)
+{
+	struct udevice *dev, *pwm, *gpio, *reg;
+	uint period_ns, duty_ns;
+	bool enable, polarity;
+	struct display_timing timing;
+
+	ut_assertok(uclass_first_device_err(UCLASS_VIDEO_BRIDGE, &dev));
+	ut_assertok(uclass_get_device_by_name(UCLASS_PWM, "pwm", &pwm));
+	ut_assertok(uclass_get_device(UCLASS_GPIO, 1, &gpio));
+	ut_assertok(regulator_get_by_platname("VDD_EMMC_1.8V", &reg));
+	ut_assertok(sandbox_pwm_get_config(pwm, 0, &period_ns, &duty_ns,
+					   &enable, &polarity));
+	ut_asserteq(false, enable);
+	ut_asserteq(true, regulator_get_enable(reg));
+
+	/* bridge calls panel_enable_backlight() of panel */
+	ut_assertok(video_bridge_attach(dev));
+	ut_assertok(sandbox_pwm_get_config(pwm, 0, &period_ns, &duty_ns,
+					   &enable, &polarity));
+	ut_asserteq(1000, period_ns);
+	ut_asserteq(170 * 1000 / 255, duty_ns);
+	ut_asserteq(true, enable);
+	ut_asserteq(false, polarity);
+	ut_asserteq(1, sandbox_gpio_get_value(gpio, 1));
+	ut_asserteq(true, regulator_get_enable(reg));
+
+	/* bridge calls panel_set_backlight() of panel */
+	ut_assertok(video_bridge_set_backlight(dev, BACKLIGHT_DEFAULT));
+	ut_assertok(sandbox_pwm_get_config(pwm, 0, &period_ns, &duty_ns,
+					   &enable, &polarity));
+	ut_asserteq(true, enable);
+	ut_asserteq(170 * 1000 / 255, duty_ns);
+
+	/* bridge should be active */
+	ut_assertok(video_bridge_set_active(dev, true));
+
+	/* bridge is internal and has no hotplug gpio */
+	ut_asserteq(-ENOENT, video_bridge_check_attached(dev));
+
+	/* check passing timings and EDID */
+	ut_assertok(video_bridge_get_display_timing(dev, &timing));
+	ut_assertok(video_bridge_read_edid(dev, NULL, 0));
+
+	return 0;
+}
+DM_TEST(dm_test_video_bridge, UTF_SCAN_PDATA | UTF_SCAN_FDT);