test: Add tests for the extcon

Provide tests to the simple extcon device.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/extcon/Kconfig b/drivers/extcon/Kconfig
index 8a50250..6fd3d2b 100644
--- a/drivers/extcon/Kconfig
+++ b/drivers/extcon/Kconfig
@@ -12,4 +12,11 @@
 	  and to host USB ports. Many of 30-pin connectors including PDMI
 	  are also good examples.
 
+config EXTCON_SANDBOX
+	bool "Sandbox extcon"
+	depends on EXTCON
+	help
+	  Enable extcon support for sandbox. This is an emulation of a real
+	  extcon. Currectly all configuration is done in the probe.
+
 endmenu
diff --git a/drivers/extcon/Makefile b/drivers/extcon/Makefile
index 2510e91..c4223d9 100644
--- a/drivers/extcon/Makefile
+++ b/drivers/extcon/Makefile
@@ -3,3 +3,4 @@
 # Copyright (C) 2023 Svyatoslav Ryhel <clamor95@gmail.com>
 
 obj-$(CONFIG_EXTCON) += extcon-uclass.o
+obj-$(CONFIG_EXTCON_SANDBOX) += extcon-sandbox.o
diff --git a/drivers/extcon/extcon-sandbox.c b/drivers/extcon/extcon-sandbox.c
new file mode 100644
index 0000000..ab6a6c1
--- /dev/null
+++ b/drivers/extcon/extcon-sandbox.c
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <dm.h>
+
+static const struct udevice_id sandbox_extcon_ids[] = {
+	{ .compatible = "sandbox,extcon" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(extcon_sandbox) = {
+	.name		= "extcon_sandbox",
+	.id		= UCLASS_EXTCON,
+	.of_match	= sandbox_extcon_ids,
+};