From: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
Properly document the function of the mgb4 output "frame_rate" sysfs parameter
and update the default DV timings values according to the latest code changes.
Signed-off-by: Martin Tůma <martin.tuma@xxxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/media/mgb4.rst | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/Documentation/admin-guide/media/mgb4.rst b/Documentation/admin-guide/media/mgb4.rst
index e434d4a9eeb3..b9da127c074d 100644
--- a/Documentation/admin-guide/media/mgb4.rst
+++ b/Documentation/admin-guide/media/mgb4.rst
@@ -227,8 +227,13 @@ 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.
@@ -253,33 +258,33 @@ 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
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--
2.45.1
