feat(isp): support isp dma input and add example

Co-authored-by: Cursor <cursoragent@cursor.com>

docs/en/api-reference/peripherals/isp.rst

@@ -240,6 +240,15 @@ Before doing ISP pipeline, you need to enable the ISP processor first, by callin
 
 Calling :cpp:func:`esp_isp_disable` does the opposite, that is, put the driver back to the **init** state.
 
+.. _isp-dma-input:
+
+ISP DMA Input
+~~~~~~~~~~~~~
+
+Besides image streams from camera controllers, the ISP can also read image frames from system memory through DW-GDMA. To use DMA input, set :cpp:member:`esp_isp_processor_cfg_t::input_data_source` in :cpp:type:`esp_isp_processor_cfg_t` to :cpp:enumerator:`ISP_INPUT_DATA_SOURCE_DWGDMA`, and configure the input format, output format, and resolution according to the image frame.
+
+DMA input is useful for feeding software-generated data, offline RAW images, or other test images in memory into the ISP. It can be used to validate an ISP pipeline without a camera sensor, reproduce issues with a specific input image, or generate inspectable output images in pytest. Call :cpp:func:`esp_isp_dma_process_frame` to send one input buffer to the ISP and write the processed image into an output buffer. The input and output buffers must be accessible by DMA; if cacheable memory is used, perform the required cache synchronization before and after the DMA transfer.
+
 ISP AF Controller
 ~~~~~~~~~~~~~~~~~
 
@@ -847,7 +856,6 @@ Calling :cpp:func:`esp_isp_crop_disable` does the opposite, that is, put the dri
     - The crop region cannot exceed the boundaries of the original image
     - Adjust the display medium (such as LCD) size according to the cropped resolution to ensure complete display and avoid black borders or stretching.
 
-
 .. _isp-callback:
 
 Register Event Callbacks
@@ -957,6 +965,8 @@ Application Examples
 --------------------
 
 * :example:`peripherals/isp/multi_pipelines` demonstrates how to use the ISP pipelines to process the image signals from camera sensors and display the video on LCD screen via DSI peripheral.
+* :example:`peripherals/isp/dma_input` demonstrates how to feed software-generated RAW8 Bayer data into the ISP through DW-GDMA and save the processed RGB888 frames as PPM images in pytest.
+* `esp_video/examples <https://github.com/espressif/esp-video-components/tree/master/esp_video/examples>`_ provides some examples of enabling ISP control algorithms.
 
 API Reference
 -------------

docs/zh_CN/api-reference/peripherals/isp.rst

@@ -240,6 +240,15 @@ ISP
 
 调用 :cpp:func:`esp_isp_disable` 函数会执行相反的操作，即将驱动程序恢复到 **init** 状态。
 
+.. _isp-dma-input:
+
+ISP DMA 输入
+~~~~~~~~~~~~
+
+除来自摄像头控制器的数据流外，ISP 还可以通过 DW-GDMA 从系统存储中读取图像帧作为输入。使用 DMA 输入时，应在 :cpp:type:`esp_isp_processor_cfg_t` 中将 :cpp:member:`esp_isp_processor_cfg_t::input_data_source` 配置为 :cpp:enumerator:`ISP_INPUT_DATA_SOURCE_DWGDMA`，并根据输入图像格式设置输入、输出格式及分辨率。
+
+DMA 输入适用于将软件生成的数据、离线保存的 RAW 图像或其他内存中的测试图像送入 ISP 进行处理。它可用于无摄像头传感器参与时验证 ISP 流水线、复现特定输入图像的问题，或在 pytest 中生成可检查的输出图像。调用 :cpp:func:`esp_isp_dma_process_frame` 可以将一帧输入缓冲区送入 ISP，并将处理后的图像写入输出缓冲区。输入和输出缓冲区需要满足 DMA 访问要求；若使用带 cache 的内存，请在 DMA 传输前后执行必要的 cache 同步。
+
 ISP AF 控制器
 ~~~~~~~~~~~~~
 
@@ -956,6 +965,8 @@ Kconfig 选项 :ref:`CONFIG_ISP_CTRL_FUNC_IN_IRAM` 支持：
 --------
 
 * :example:`peripherals/isp/multi_pipelines` 演示了如何使用 ISP 流水线处理来自摄像头传感器的图像信号，并通过 DSI 外设在 LCD 屏幕上显示视频。
+* :example:`peripherals/isp/dma_input` 演示了如何通过 DW-GDMA 将软件生成的 RAW8 Bayer 数据送入 ISP，并在 pytest 中将处理后的 RGB888 帧保存为 PPM 图片。
+* `esp_video/examples <https://github.com/espressif/esp-video-components/tree/master/esp_video/examples>`_ 中包含自动启用 ISP 控制算法的一些示例。
 
 API 参考
 --------