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Diffstat (limited to 'Documentation/admin-guide/media/mgb4.rst')
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1 files changed, 41 insertions, 30 deletions
diff --git a/Documentation/admin-guide/media/mgb4.rst b/Documentation/admin-guide/media/mgb4.rst index 2977f74d7e26..5ac69b833a7a 100644 --- a/Documentation/admin-guide/media/mgb4.rst +++ b/Documentation/admin-guide/media/mgb4.rst @@ -1,8 +1,19 @@ .. SPDX-License-Identifier: GPL-2.0 -==================== -mgb4 sysfs interface -==================== +.. include:: <isonum.txt> + +The mgb4 driver +=============== + +Copyright |copy| 2023 - 2025 Digiteq Automotive + author: Martin Tůma <martin.tuma@digiteqautomotive.com> + +This is a v4l2 device driver for the Digiteq Automotive FrameGrabber 4, a PCIe +card capable of capturing and generating FPD-Link III and GMSL2/3 video streams +as used in the automotive industry. + +sysfs interface +--------------- The mgb4 driver provides a sysfs interface, that is used to configure video stream related parameters (some of them must be set properly before the v4l2 @@ -12,16 +23,17 @@ There are two types of parameters - global / PCI card related, found under ``/sys/class/video4linux/videoX/device`` and module specific found under ``/sys/class/video4linux/videoX``. - Global (PCI card) parameters -============================ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **module_type** (R): Module type. | 0 - No module present | 1 - FPDL3 - | 2 - GMSL + | 2 - GMSL (one serializer, two daisy chained deserializers) + | 3 - GMSL (one serializer, two deserializers) + | 4 - GMSL (two deserializers with two daisy chain outputs) **module_version** (R): Module version number. Zero in case of a missing module. @@ -42,9 +54,8 @@ Global (PCI card) parameters where each component is a 8b number. - Common FPDL3/GMSL input parameters -================================== +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **input_id** (R): Input number ID, zero based. @@ -190,9 +201,8 @@ Common FPDL3/GMSL input parameters *Note: This parameter can not be changed while the input v4l2 device is open.* - Common FPDL3/GMSL output parameters -=================================== +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **output_id** (R): Output number ID, zero based. @@ -228,8 +238,13 @@ Common FPDL3/GMSL output parameters open.* **frame_rate** (RW): - Output video frame rate in frames per second. The default frame rate is - 60Hz. + Output video signal frame rate limit in frames per second. Due to + the limited output pixel clock steps, the card can not always generate + a frame rate perfectly matching the value required by the connected display. + Using this parameter one can limit the frame rate by "crippling" the signal + so that the lines are not equal (the porches of the last line differ) but + the signal appears like having the exact frame rate to the connected display. + The default frame rate limit is 60Hz. **hsync_polarity** (RW): HSYNC signal polarity. @@ -254,37 +269,36 @@ Common FPDL3/GMSL output parameters and there is a non-linear stepping between two consecutive allowed frequencies. The driver finds the nearest allowed frequency to the given value and sets it. When reading this property, you get the exact - frequency set by the driver. The default frequency is 70000kHz. + frequency set by the driver. The default frequency is 61150kHz. *Note: This parameter can not be changed while the output v4l2 device is open.* **hsync_width** (RW): - Width of the HSYNC signal in pixels. The default value is 16. + Width of the HSYNC signal in pixels. The default value is 40. **vsync_width** (RW): - Width of the VSYNC signal in video lines. The default value is 2. + Width of the VSYNC signal in video lines. The default value is 20. **hback_porch** (RW): Number of PCLK pulses between deassertion of the HSYNC signal and the first - valid pixel in the video line (marked by DE=1). The default value is 32. + valid pixel in the video line (marked by DE=1). The default value is 50. **hfront_porch** (RW): Number of PCLK pulses between the end of the last valid pixel in the video line (marked by DE=1) and assertion of the HSYNC signal. The default value - is 32. + is 50. **vback_porch** (RW): Number of video lines between deassertion of the VSYNC signal and the video - line with the first valid pixel (marked by DE=1). The default value is 2. + line with the first valid pixel (marked by DE=1). The default value is 31. **vfront_porch** (RW): Number of video lines between the end of the last valid pixel line (marked - by DE=1) and assertion of the VSYNC signal. The default value is 2. - + by DE=1) and assertion of the VSYNC signal. The default value is 30. FPDL3 specific input parameters -=============================== +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **fpdl3_input_width** (RW): Number of deserializer input lines. @@ -294,7 +308,7 @@ FPDL3 specific input parameters | 2 - dual FPDL3 specific output parameters -================================ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **fpdl3_output_width** (RW): Number of serializer output lines. @@ -304,7 +318,7 @@ FPDL3 specific output parameters | 2 - dual GMSL specific input parameters -============================== +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ **gmsl_mode** (RW): GMSL speed mode. @@ -328,10 +342,8 @@ GMSL specific input parameters | 0 - disabled | 1 - enabled (default) - -==================== -mgb4 mtd partitions -==================== +MTD partitions +-------------- The mgb4 driver creates a MTD device with two partitions: - mgb4-fw.X - FPGA firmware. @@ -344,9 +356,8 @@ also have a third partition named *mgb4-flash* available in the system. This partition represents the whole, unpartitioned, card's FLASH memory and one should not fiddle with it... -==================== -mgb4 iio (triggers) -==================== +IIO (triggers) +-------------- The mgb4 driver creates an Industrial I/O (IIO) device that provides trigger and signal level status capability. The following scan elements are available: |