1 .. SPDX-License-Identifier: GPL-2.0 1 .. SPDX-License-Identifier: GPL-2.0
2 2
3 .. _v4l2-meta-fmt-rpi-be-cfg: 3 .. _v4l2-meta-fmt-rpi-be-cfg:
4 4
5 ************************ 5 ************************
6 V4L2_META_FMT_RPI_BE_CFG 6 V4L2_META_FMT_RPI_BE_CFG
7 ************************ 7 ************************
8 8
9 Raspberry Pi PiSP Back End configuration forma 9 Raspberry Pi PiSP Back End configuration format
10 ============================================== 10 ===============================================
11 11
12 The Raspberry Pi PiSP Back End memory-to-memor 12 The Raspberry Pi PiSP Back End memory-to-memory image signal processor is
13 configured by userspace by providing a buffer 13 configured by userspace by providing a buffer of configuration parameters
14 to the `pispbe-config` output video device nod 14 to the `pispbe-config` output video device node using the
15 :c:type:`v4l2_meta_format` interface. 15 :c:type:`v4l2_meta_format` interface.
16 16
17 The PiSP Back End processes images in tiles, a 17 The PiSP Back End processes images in tiles, and its configuration requires
18 specifying two different sets of parameters by 18 specifying two different sets of parameters by populating the members of
19 :c:type:`pisp_be_tiles_config` defined in the 19 :c:type:`pisp_be_tiles_config` defined in the ``pisp_be_config.h`` header file.
20 20
21 The `Raspberry Pi PiSP technical specification 21 The `Raspberry Pi PiSP technical specification
22 <https://datasheets.raspberrypi.com/camera/ras 22 <https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf>`_
23 provide detailed description of the ISP back e 23 provide detailed description of the ISP back end configuration and programming
24 model. 24 model.
25 25
26 Global configuration data 26 Global configuration data
27 ------------------------- 27 -------------------------
28 28
29 The global configuration data describe how the 29 The global configuration data describe how the pixels in a particular image are
30 to be processed and is therefore shared across 30 to be processed and is therefore shared across all the tiles of the image. So
31 for example, LSC (Lens Shading Correction) or 31 for example, LSC (Lens Shading Correction) or Denoise parameters would be common
32 across all tiles from the same frame. 32 across all tiles from the same frame.
33 33
34 Global configuration data are passed to the IS 34 Global configuration data are passed to the ISP by populating the member of
35 :c:type:`pisp_be_config`. 35 :c:type:`pisp_be_config`.
36 36
37 Tile parameters 37 Tile parameters
38 --------------- 38 ---------------
39 39
40 As the ISP processes images in tiles, each set 40 As the ISP processes images in tiles, each set of tiles parameters describe how
41 a single tile in an image is going to be proce 41 a single tile in an image is going to be processed. A single set of tile
42 parameters consist of 160 bytes of data and to 42 parameters consist of 160 bytes of data and to process a batch of tiles several
43 sets of tiles parameters are required. 43 sets of tiles parameters are required.
44 44
45 Tiles parameters are passed to the ISP by popu 45 Tiles parameters are passed to the ISP by populating the member of
46 ``pisp_tile`` and the ``num_tiles`` fields of 46 ``pisp_tile`` and the ``num_tiles`` fields of :c:type:`pisp_be_tiles_config`.
47 47
48 Raspberry Pi PiSP Back End uAPI data types 48 Raspberry Pi PiSP Back End uAPI data types
49 ========================================== 49 ==========================================
50 50
51 This section describes the data types exposed 51 This section describes the data types exposed to userspace by the Raspberry Pi
52 PiSP Back End. The section is informative only 52 PiSP Back End. The section is informative only, for a detailed description of
53 each field refer to the `Raspberry Pi PiSP tec 53 each field refer to the `Raspberry Pi PiSP technical specification
54 <https://datasheets.raspberrypi.com/camera/ras 54 <https://datasheets.raspberrypi.com/camera/raspberry-pi-image-signal-processor-specification.pdf>`_.
55 55
56 .. kernel-doc:: include/uapi/linux/media/raspb 56 .. kernel-doc:: include/uapi/linux/media/raspberrypi/pisp_be_config.h
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.