drivers: video: sw_generator: convert to use the devicetree

Make the video software generator a devicetree node, which allows enabling
several instances, and select it as chosen { zephyr,camera = &... }; node.
It can be enabled via a `video-sw-generator` snippet.

Signed-off-by: Josuah Demangeon <me@josuah.net>

drivers/video/Kconfig.sw_generator

@@ -1,12 +1,9 @@
-# MT9m114
-
 # Copyright (c) 2016 Linaro Limited
 # SPDX-License-Identifier: Apache-2.0
 
-DT_CHOSEN_ZEPHYR_CAMERA := zephyr,camera
-
 config VIDEO_SW_GENERATOR
 	bool "Video Software Generator"
-	depends on !$(dt_chosen_enabled,$(DT_CHOSEN_ZEPHYR_CAMERA))
+	depends on DT_HAS_ZEPHYR_VIDEO_SW_GENERATOR_ENABLED
+	default y
 	help
 	  Enable video pattern generator (for testing purposes).

drivers/video/video_sw_generator.c

@@ -4,7 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-#define DT_DRV_COMPAT zephyr_sw_generator
+#define DT_DRV_COMPAT zephyr_video_sw_generator
 
 #include <zephyr/drivers/video-controls.h>
 #include <zephyr/drivers/video.h>
@@ -451,14 +451,6 @@ static DEVICE_API(video, video_sw_generator_driver_api) = {
 #endif
 };
 
-static struct video_sw_generator_data video_sw_generator_data_0 = {
-	.fmt.width = 320,
-	.fmt.height = 160,
-	.fmt.pitch = 320 * 2,
-	.fmt.pixelformat = VIDEO_PIX_FMT_RGB565,
-	.frame_rate = DEFAULT_FRAME_RATE,
-};
-
 static int video_sw_generator_init_controls(const struct device *dev)
 {
 	struct video_sw_generator_data *data = dev->data;
@@ -479,8 +471,19 @@ static int video_sw_generator_init(const struct device *dev)
 	return video_sw_generator_init_controls(dev);
 }
 
-DEVICE_DEFINE(video_sw_generator, "VIDEO_SW_GENERATOR", &video_sw_generator_init, NULL,
+#define VIDEO_SW_GENERATOR_DEFINE(n)                                                               \
-	      &video_sw_generator_data_0, NULL, POST_KERNEL, CONFIG_VIDEO_INIT_PRIORITY,
+	static struct video_sw_generator_data video_sw_generator_data_##n = {                      \
-	      &video_sw_generator_driver_api);
+		.fmt.width = 320,                                                                  \
-
+		.fmt.height = 160,                                                                 \
-VIDEO_DEVICE_DEFINE(video_sw_generator, DEVICE_GET(video_sw_generator), NULL);
+		.fmt.pitch = 320 * 2,                                                              \
+		.fmt.pixelformat = VIDEO_PIX_FMT_RGB565,                                           \
+		.frame_rate = DEFAULT_FRAME_RATE,                                                  \
+	};                                                                                         \
+                                                                                                   \
+	DEVICE_DT_INST_DEFINE(n, &video_sw_generator_init, NULL, &video_sw_generator_data_##n,     \
+			      NULL, POST_KERNEL, CONFIG_VIDEO_INIT_PRIORITY,                       \
+			      &video_sw_generator_driver_api);                                     \
+                                                                                                   \
+	VIDEO_DEVICE_DEFINE(video_sw_generator_##n, DEVICE_DT_INST_GET(n), NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(VIDEO_SW_GENERATOR_DEFINE)

dts/bindings/video/zephyr,video-sw-generator.yaml

@@ -0,0 +1,6 @@
+# Copyright 2025 tinyVision.ai Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: Emulated Video test pattern generator
+
+compatible: "zephyr,video-sw-generator"

samples/drivers/video/capture/README.rst

@@ -91,9 +91,16 @@ For :ref:`native_sim`, build this sample application with the following commands
    :goals: build
    :compact:
 
-For testing purpose without the need of any real video capture and/or display hardwares,
+For testing purpose and without the need of any real video capture and/or display hardwares,
 a video software pattern generator is supported by the above build commands without
-specifying the shields.
+specifying the shields, and using :ref:`snippet-video-sw-generator`:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/video/capture
+   :board: native_sim/native/64
+   :snippets: video-sw-generator
+   :goals: build
+   :compact:
 
 For controlling the camera device using shell commands instead of continuously capturing the data,
 append ``-DCONFIG_VIDEO_SHELL=y`` to the build command:

samples/drivers/video/capture/prj.conf

@@ -1,5 +1,4 @@
 CONFIG_VIDEO=y
-CONFIG_VIDEO_SW_GENERATOR=y
 CONFIG_SHELL=y
 CONFIG_DEVICE_SHELL=y
 CONFIG_PRINTK=y

samples/drivers/video/capture/sample.yaml

@@ -45,6 +45,8 @@ tests:
       - CONFIG_VIDEO_SHELL=y
       - CONFIG_FPU=y
       - CONFIG_DISPLAY=n
+    extra_args:
+      - platform:native_sim/native/64:SNIPPET="video-sw-generator"
     harness: console
     harness_config:
       type: one_line

samples/drivers/video/capture/src/main.c

@@ -23,8 +23,6 @@ LOG_MODULE_REGISTER(main);
 #define LOG_LEVEL CONFIG_LOG_DEFAULT_LEVEL
 #endif
 
-#define VIDEO_DEV_SW "VIDEO_SW_GENERATOR"
-
 #if DT_HAS_CHOSEN(zephyr_display)
 static inline int display_setup(const struct device *const display_dev, const uint32_t pixfmt)
 {
@@ -92,6 +90,7 @@ int main(void)
 {
 	struct video_buffer *buffers[CONFIG_VIDEO_BUFFER_POOL_NUM_MAX];
 	struct video_buffer *vbuf = &(struct video_buffer){};
+	const struct device *video_dev;
 	struct video_format fmt;
 	struct video_caps caps;
 	struct video_frmival frmival;
@@ -108,21 +107,11 @@ int main(void)
 		return 0;
 	}
 
-#if DT_HAS_CHOSEN(zephyr_camera)
+	video_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_camera));
-	const struct device *const video_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_camera));
-
 	if (!device_is_ready(video_dev)) {
 		LOG_ERR("%s: video device is not ready", video_dev->name);
 		return 0;
 	}
-#else
-	const struct device *const video_dev = device_get_binding(VIDEO_DEV_SW);
-
-	if (video_dev == NULL) {
-		LOG_ERR("%s: video device not found or failed to initialized", VIDEO_DEV_SW);
-		return 0;
-	}
-#endif
 
 	LOG_INF("Video device: %s", video_dev->name);
 

samples/drivers/video/capture_to_lvgl/README.rst

@@ -37,6 +37,16 @@ For :zephyr:board:`mini_stm32h743`, build this sample application with the follo
    :gen-args: -DCONFIG_BOOT_DELAY=2000
    :compact:
 
+For testing purpose and without the need of any real video capture hardware,
+a video software pattern generator is supported by using :ref:`snippet-video-sw-generator`:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/video/capture
+   :board: native_sim/native/64
+   :snippets: video-sw-generator
+   :goals: build
+   :compact:
+
 Sample Output
 =============
 

samples/drivers/video/capture_to_lvgl/prj.conf

@@ -1,5 +1,4 @@
 CONFIG_VIDEO=y
-CONFIG_VIDEO_SW_GENERATOR=y
 
 CONFIG_PRINTK=y
 CONFIG_LOG=y

samples/drivers/video/capture_to_lvgl/src/main.c

@@ -15,17 +15,15 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(main);
 
-#define VIDEO_DEV_SW "VIDEO_SW_GENERATOR"
-
 int main(void)
 {
 	struct video_buffer *buffers[2];
 	struct video_buffer *vbuf = &(struct video_buffer){};
 	const struct device *display_dev;
+	const struct device *video_dev;
 	struct video_format fmt;
 	struct video_caps caps;
 	enum video_buf_type type = VIDEO_BUF_TYPE_OUTPUT;
-	const struct device *video_dev;
 	size_t bsize;
 	int i = 0;
 
@@ -35,19 +33,11 @@ int main(void)
 		return 0;
 	}
 
-#if DT_HAS_CHOSEN(zephyr_camera)
 	video_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_camera));
 	if (!device_is_ready(video_dev)) {
 		LOG_ERR("%s device is not ready", video_dev->name);
 		return 0;
 	}
-#else
-	video_dev = device_get_binding(VIDEO_DEV_SW);
-	if (video_dev == NULL) {
-		LOG_ERR("%s device not found", VIDEO_DEV_SW);
-		return 0;
-	}
-#endif
 
 	LOG_INF("- Device name: %s", video_dev->name);
 

samples/drivers/video/tcpserversink/README.rst

@@ -39,6 +39,16 @@ If a mt9m114 camera shield is missing, video software generator will be used ins
    :goals: build
    :compact:
 
+For testing purpose and without the need of any real video capture hardware,
+a video software pattern generator is supported by using :ref:`snippet-video-sw-generator`:
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/drivers/video/capture
+   :board: native_sim/native/64
+   :snippets: video-sw-generator
+   :goals: build
+   :compact:
+
 Sample Output
 =============
 

samples/drivers/video/tcpserversink/prj.conf

@@ -40,4 +40,3 @@ CONFIG_NET_CONFIG_SETTINGS=y
 CONFIG_NET_CONFIG_MY_IPV4_ADDR="192.0.2.1"
 
 CONFIG_VIDEO=y
-CONFIG_VIDEO_SW_GENERATOR=y

samples/drivers/video/tcpserversink/src/main.c

@@ -15,7 +15,6 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(main);
 
-#define VIDEO_DEV_SW     "VIDEO_SW_GENERATOR"
 #define MY_PORT          5000
 #define MAX_CLIENT_QUEUE 1
 
@@ -44,21 +43,14 @@ int main(void)
 	struct video_format fmt;
 	struct video_caps caps;
 	enum video_buf_type type = VIDEO_BUF_TYPE_OUTPUT;
-#if DT_HAS_CHOSEN(zephyr_camera)
+	const struct device *video;
-	const struct device *const video = DEVICE_DT_GET(DT_CHOSEN(zephyr_camera));
 
+	video = DEVICE_DT_GET(DT_CHOSEN(zephyr_camera));
 	if (!device_is_ready(video)) {
 		LOG_ERR("%s: video device not ready.", video->name);
 		return 0;
 	}
-#else
-	const struct device *const video = device_get_binding(VIDEO_DEV_SW);
 
-	if (video == NULL) {
-		LOG_ERR("%s: video device not found or failed to initialized.", VIDEO_DEV_SW);
-		return 0;
-	}
-#endif
 	/* Prepare Network */
 	(void)memset(&addr, 0, sizeof(addr));
 	addr.sin_family = AF_INET;

snippets/video-sw-generator/README.rst

@@ -0,0 +1,20 @@
+.. _snippet-video-sw-generator:
+
+Video Software Generator Snippet (video-sw-generator)
+#####################################################
+
+.. code-block:: console
+
+   west build -S video-sw-generator [...]
+
+Overview
+********
+
+This snippet instantiate a fake video source generating a test pattern continuously
+for test purpose. It is selected as the ``zephyr,camera`` :ref:`devicetree` chosen node.
+
+Requirements
+************
+
+No hardware support is required besides sufficient memory for the video resolution
+declared by :kconfig:option:`CONFIG_VIDEO_BUFFER_POOL_SZ_MAX`.

snippets/video-sw-generator/snippet.yml

@@ -0,0 +1,3 @@
+name: video-sw-generator
+append:
+  EXTRA_DTC_OVERLAY_FILE: video-sw-generator.overlay

snippets/video-sw-generator/video-sw-generator.overlay

@@ -0,0 +1,14 @@
+/*
+ * Copyright The Zephyr Project Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	chosen {
+		zephyr,camera = &video_sw_generator;
+	};
+
+	video_sw_generator: video-sw-generator {
+		compatible = "zephyr,video-sw-generator";
+	};
+};