[PATCH] pinctrl/rockchip: re-fix RK3308 pinmux bits

[jay.xu at rock-chips.com]

Hi Luca

--------------
jay.xu at rock-chips.com
>Hello jay.xu, kever,
>
>On Mon, 10 Oct 2022 16:04:39 +0200
>Luca Ceresoli <luca.ceresoli at bootlin.com> wrote:
>
>> Hello jay.xu, kever,
>>
>> On Sun, 2 Oct 2022 09:44:02 +0800
>> "jay.xu at rock-chips.com" <jay.xu at rock-chips.com> wrote:
>>
>> > Hi Luca：
>> >
>> > --------------
>> > jay.xu at rock-chips.com
>> > >Hello Jianqun,
>> > >
>> > >Il giorno Sat, 1 Oct 2022 08:42:25 +0800
>> > >"jay.xu at rock-chips.com" <jay.xu at rock-chips.com> ha scritto:
>> > > 
>> > >> Hi Luca:
>> > >>
>> > >> BR
>> > >> --------------
>> > >> jay.xu at rock-chips.com 
>> > >> >Hello Jianqun Xu,
>> > >> >
>> > >> >On Fri, 30 Sep 2022 18:26:20 +0800
>> > >> >Jianqun Xu <jay.xu at rock-chips.com> wrote:
>> > >> >  
>> > >> >> Part of pins from RK3308 SoCs have two registers to do pinmux, one is
>> > >> >> the origin register with 2bits named by gpioxx_sel, and another with
>> > >> >> 3bits and named by gpioxx_sel_plus.  
>> > >> >
>> > >> >Are the "plus" registers documented anywhere?   
>> > >>
>> > >> At RK3308 TRM CH5 GRF, 
>> > >>
>> > >> GRF_SOC_CON13 
>> > >>
>> > >> 3  RW  0x0 gpio2a2_sel_src_ctrl
>> > >>                   IOMUX control source selection.
>> > >>                  1'b0: use basic GPIO2A_IOMUX[gpio2a2_sel]
>> > >>                  1'b1: use gpio2a2_sel_plus instead of GPIO2A_IOMUX[gpio2a2_sel]
>> > >>
>> > >> 2:0  RW  0x0 gpio2a2_sel_plus
>> > >>                      3'b000: GPIO2_A2
>> > >>                      3'b001: UART0_CTSN
>> > >>                      3'b010: SPI0_CLK
>> > >>                      3'b011: I2C2_SDA
>> > >>                      3'b100: Reserved
>> > >>                      3'b101: OWIRE_M2
>> > >>
>> > >> Sorry I don't know about the trm you got from our company, if you cannot find this part,
>> > >> may require a new version ? 
>> > >
>> > >First of all: is a complete TRM available for public download?  
>> >
>> > https://opensource.rock-chips.com/wiki_Main_Page
>> > @kever should add a trm for rk3308 ?
>>
>> Indeed it would be great to have the documentation available in the
>> above page! With that one would be able to understand the code, e.g. I
>> would have understood on my own what register 0x608/0x610 is and I
>> would not have sent my initial patch as is.
>>
>> So I subscribe to the proposal by Jay to have the complete TRM online!
>
>While I am still sure that public, complete documentation is the best
>for the benefit of Linux support, from the lack of feedback I suspect
>this is not coming soon.
>
>While we wait for it to happen, I think the best way to move forward is
>to at least add a complete list of the possible values for the "plus"
>registers in the kernel source code, either in the driver or in
>rk3308.dtsi. I consider this the very minimum needed. Without this, the
>next developer will also be unable to use SPI or some other feature,
>perhaps sending another patch to fix the same issue, breaking it again.
>
>Would you be OK with doing that? 

okay, it depends on kever to update the trm or not, patch can be halt on currently

>
>Best regards.
>--
>Luca Ceresoli, Bootlin
>Embedded Linux and Kernel engineering
>https://bootlin.com