rk3568-pinctrl for LCD RGB666/RGB656

[Andy Yan]

Hi Michael:

On 6/2/22 14:41, Michael Riesch wrote:
> Hi Andy,
>
> Thanks a lot for providing the pin mappings.
>
> On 6/2/22 03:38, Andy Yan wrote:
>> Hi Michael:
>>
>> On 5/27/22 20:46, Michael Riesch wrote:
>>> Hello Liang,
>>>
>>> According to the RK3568 TRM the Video Output Processor (VOP2) is able to
>>> emit parallel RGB data to LCDs in 24-bit (888), 18-bit (666) and 16-bit
>>> (565) format. Based on this I would have expected that
>>> rk3568-pinctrl.dtsi specifies one group of control pins (clock, hsync,
>>> vsync, data enable) and three groups of data pins (with 24, 18, 16 pins,
>>> respectively). Does this sound reasonable?
> Just for clarification: Can the data pins which are not used by the LCD
> in the respective operating mode be configured independently to their
> alternative function? For example, can the pins D16 and D17 be used as
> GPIOs or UART4_{TX,RX} in RGB666 mode?
>
> If yes, it would probably make sense to reflect this in the
> rk3568-pinctrl.dtsi by adding different groups of data pins.


Yes, it is possible, you can do that.

>
>>> However, there is only one group with the control pins and the data pins
>>> D0 - D23. I cannot tell which pins have to be assigned to the different
>>> groups. They are mapped 1:1 to Rockchip pin names (e.g., D0 is mapped to
>>> GPIO2_PD0) but it is not clear which function (channel, bit) each pin
>>> has in this context. Could you please elaborate on the mapping of the D0
>>> - D23 pins in the different operating modes?
>>
>> For 18-bit(RGB666),
>>
>> R0~R5 map to D18~D23
>>
>> G0~G5 map to D10~D15
>>
>> B0~B5 map to D2~D7
>>
>>
>> for 16-bit(RGB565)
>>
>> R0~R4 map to D17~D23
> D17 -> D19, right?
>
> Thanks and best regards,
> Michael
>
>> G0~G5 map to D10~D15
>>
>> B0~B4 map to D3~D7
>>
>>> Thanks and regards,
>>> Michael
>>>
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