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(unknown [62.77.71.229]) by mx.gpxsee.org (Postfix) with ESMTPSA id 04ED14ABED; Fri, 31 May 2024 16:49:27 +0200 (CEST) From: tumic@gpxsee.org To: Mauro Carvalho Chehab , Hans Verkuil Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Mar?= =?utf-8?q?tin_T=C5=AFma?= Subject: [PATCH v6 4/4] media: admin-guide: mgb4: Outputs DV timings documentation update Date: Fri, 31 May 2024 16:49:21 +0200 Message-ID: <20240531144921.2104-5-tumic@gpxsee.org> X-Mailer: git-send-email 2.45.1 In-Reply-To: <20240531144921.2104-1-tumic@gpxsee.org> References: <20240531144921.2104-1-tumic@gpxsee.org> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Martin Tůma 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 --- 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 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~