drivers: video: add emulated Imager driver and RX driver

Add a new implementation of a test pattern generator, with the same
architecture as real drivers: split receiver core and
I2C-controlled sub-device, with changes of video format in
"zephyr,emul-imager" leads to different data produced by
"zephyr,emul-rx".

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

Author: josuah

drivers/video/CMakeLists.txt

@@ -16,3 +16,5 @@ zephyr_library_sources_ifdef(CONFIG_VIDEO_OV5640	ov5640.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_OV7670	ov7670.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_ESP32		video_esp32_dvp.c)
 zephyr_library_sources_ifdef(CONFIG_VIDEO_MCUX_SDMA	video_mcux_smartdma.c)
+zephyr_library_sources_ifdef(CONFIG_VIDEO_EMUL_IMAGER	video_emul_imager.c)
+zephyr_library_sources_ifdef(CONFIG_VIDEO_EMUL_RX	video_emul_rx.c)

drivers/video/Kconfig

@@ -74,4 +74,8 @@ source "drivers/video/Kconfig.gc2145"
 
 source "drivers/video/Kconfig.mcux_sdma"
 
+source "drivers/video/Kconfig.emul_imager"
+
+source "drivers/video/Kconfig.emul_rx"
+
 endif # VIDEO

drivers/video/Kconfig.emul_imager

@@ -0,0 +1,18 @@
+# Copyright (c) 2024 tinyVision.ai Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config VIDEO_EMUL_IMAGER
+	bool "Software implementation of an imager"
+	depends on DT_HAS_ZEPHYR_VIDEO_EMUL_IMAGER_ENABLED
+	default y
+	help
+	  Enable driver for the emulated Imager.
+
+config VIDEO_EMUL_IMAGER_FRAMEBUFFER_SIZE
+	int "Internal framebuffer size used for link emulation purpose"
+	default 4096
+	help
+	  Configure the size of the internal framebuffer the emulated Imager
+	  driver uses to simulate MIPI transfers. This is the first field of
+	  dev->data, and the emulated video MIPI driver will `memcpy()` it
+	  into the video buffer.

drivers/video/Kconfig.emul_rx

@@ -0,0 +1,10 @@
+# Copyright (c) 2024 tinyVision.ai Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config VIDEO_EMUL_RX
+	bool "Software implementation of video frame RX core"
+	depends on DT_HAS_ZEPHYR_VIDEO_EMUL_RX_ENABLED
+	depends on VIDEO_EMUL_IMAGER
+	default y
+	help
+	  Enable driver for the MIPI RX emulated DMA engine.