[PATCH V2 6/6] doc: anbernic: Update RGxx3 Docs for panel detection

[Kever Yang]

On 2023/5/16 00:00, Chris Morgan wrote:
> From: Chris Morgan <macromorgan at hotmail.com>
>
> Update the Anbernic RGxx3 documentation to note that panel detection
> has been added and how it works.
>
> Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
Reviewed-by: Kever Yang <kever.yang at rock-chips.com>

Thanks,
- Kever
> ---
>   doc/board/anbernic/rgxx3.rst | 31 ++++++++++++++++++++-----------
>   1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/doc/board/anbernic/rgxx3.rst b/doc/board/anbernic/rgxx3.rst
> index afa7538282..5aa676aa1d 100644
> --- a/doc/board/anbernic/rgxx3.rst
> +++ b/doc/board/anbernic/rgxx3.rst
> @@ -7,27 +7,36 @@ This allows U-Boot to boot the following Anbernic devices:
>   
>    - Anbernic RG353M
>    - Anbernic RG353P
> + - Anbernic RG353PS
>    - Anbernic RG353V
>    - Anbernic RG353VS
>    - Anbernic RG503
>   
>   The correct device is detected automatically by comparing ADC values
> -from ADC channel 1. In the event of an RG353V, an attempt is then made
> -to probe for an eMMC and if it fails the device is assumed to be an
> -RG353VS. Based on the detected device, the environment variables
> -"board", "board_name", and "fdtfile" are set to the correct values
> -corresponding to the board which can be read by a boot script to boot
> -with the correct device tree.
> -
> -Please note that there are some versions of the RG353 devices with
> -different panels. Panel auto-detection is planned for a later date.
> +from ADC channel 1. In the event of an RG353V or RG353P, an attempt
> +is then made to probe for an eMMC and if it fails the device is assumed
> +to be an RG353VS or RG353PS. Based on the detected device, the
> +environment variables "board", "board_name", and "fdtfile" are set to
> +the correct values corresponding to the board which can be read by a
> +boot script to boot with the correct device tree. If the board detected
> +is not of type RG503 (which currently has only 1 panel revision) a
> +panel detect is then performed by probing a "dummy" display on the DSI
> +bus and then querying the display ID. The display ID is then compared
> +to a table to get the known compatible string for use in Linux, and
> +this string is saved as an environment variable of "panel".
> +
> +FDT fixups are performed in the event of an RG353M to change the device
> +name, or in the event the panel detected does not match the devicetree.
> +This allows Linux to load the correct panel driver without having to
> +know exactly which panel is used (as there is no user distingushable
> +way to tell).
>   
>   Building U-Boot
>   ---------------
>   
>   .. code-block:: bash
>   
> -    $ export CROSS_COMPILE=aarch64-none-elf-
> +    $ export CROSS_COMPILE=aarch64-linux-gnu-
>       $ export BL31=../rkbin/bin/rk35/rk3568_bl31_v1.34.elf
>       $ export ROCKCHIP_TPL=../rkbin/bin/rk35/rk3568_ddr_1056MHz_v1.13.bin
>       $ make anbernic-rgxx3_defconfig
> @@ -40,7 +49,7 @@ Image installation
>   ------------------
>   
>   Write the ``u-boot-rockchip.bin`` to an SD card offset 32kb from the
> -start.
> +start. Please note that eMMC booting has not been tested at this time.
>   
>   .. code-block:: bash
>