Re: [PATCH] pinctrl: sunxi: Add H3 R_PIO controller support

[Krzysztof Adamski]

On Tue, Feb 02, 2016 at 10:24:51AM +0100, Krzysztof Adamski wrote:
> On Tue, Feb 02, 2016 at 02:25:18PM +0800, Chen-Yu Tsai wrote:
> > On Mon, Feb 1, 2016 at 6:12 PM, Krzysztof Adamski <k@xxxxxxxx> wrote:
> > > - reg: Should contain the register physical address and length for 
> > > the
> > > diff --git a/arch/arm/boot/dts/sun8i-h3.dtsi
> > > b/arch/arm/boot/dts/sun8i-h3.dtsi
> > > index 1524130e..745f64c 100644
> > > --- a/arch/arm/boot/dts/sun8i-h3.dtsi
> > > +++ b/arch/arm/boot/dts/sun8i-h3.dtsi
> > > @@ -493,5 +493,17 @@
> > >                        interrupts = <GIC_SPI 40 IRQ_TYPE_LEVEL_HIGH>,
> > >                                     <GIC_SPI 41 IRQ_TYPE_LEVEL_HIGH>;
> > >                };
> > > +
> > > +               r_pio: pinctrl@01f02c00 {
> > > +                       compatible = "allwinner,sun8i-h3-r-pinctrl";
> > > +                       reg = <0x01f02c00 0x400>;
> > > +                       interrupts = <GIC_SPI 45 IRQ_TYPE_LEVEL_HIGH>;
> > > +                       clocks = <&bus_gates 69>;
> >
> > This is probably wrong. According to other SoCs all R_ block peripherals
> > have clock gates and reset controls in the PRCM.
>
> This is problematic. I can find information about reset and gates control for
> this peripheral on other SoCs user manuals but there is nothing about it in H3
> User Manual
> (https://www.dropbox.com/s/nkr9slo1o9x6i1z/Allwinner_H3_Datasheet_V1.1.pdf?dl=0).
>
> Similarly, while I think I can find r_pio clock setup for A33:
> https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/clk/sunxi/clk-sun8iw5.c
>
> I can't find it for H3, though:
> https://github.com/allwinner-zh/linux-3.4-sunxi/blob/master/drivers/clk/sunxi/clk-sun8iw7.c
>
> Well, apart from this strange snippet:
>
> // binder r-pio CPUS_APB0_GATE to pio-clk's gate-reset-register
>   clk = clk_get(NULL,"pio");
>   if(!clk || IS_ERR(clk))
>       printk("Error not get clk pio\n");
>   else
>   {
>       struct clk_hw *hw = __clk_get_hw(clk);
>       struct sunxi_clk_periph *periph = to_clk_periph(hw);
>       struct sunxi_clk_periph_gate *gate = &periph->gate;
>       gate->reset = sunxi_clk_cpus_base+CPUS_APB0_GATE ;
>       gate->rst_shift = 0;
>       clk_put(clk);
>   }
>
>
> Which I have to admit I don't fully understand. This seems to be setting reset
> line for first pio, not for r_pio - something we don't have right now. Or am I
> wrong here?
>
> I'm new to Allwinner SoCs, any help from veterans?
>
> Also, if that proves anything, I did test this code on OrangePi PC and PL ports
> works so their clock is enabled, for sure.

I did some tests and indeed, when I disabled PIO clock (bus_gates 69), 
R_PIO was still working while PIO did not. So I tryied to take the same 
address other SoCs are using (0x01f01468 - CPUS_APB0 register) and 
clearing 1st bit (which is enabled by default) disables R_PIO. So, well, 
it seems that this works the same as on other sunxi SoCs. I'll try doing 
proper change.

Best regards,
Krzysztof Adamski