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SubjectRe: [PATCH v4 9/9] ARM: dts: rockchip: support the spi for rk3036
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Heiko,

在 2016年01月31日 19:06, Heiko Stuebner 写道:
> Hi Caesar,
>
> Am Donnerstag, 28. Januar 2016, 16:43:38 schrieb Caesar Wang:

[...]

>
> memory {
> @@ -485,6 +486,23 @@
> status = "disabled";
> };
>
> + spi: spi@20074000 {
> + compatible = "rockchip,rockchip-spi";
> + reg = <0x20074000 0x1000>;
> + interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&spi_txd &spi_rxd &spi_clk &spi_cs0 &spi_cs1>;
> Do we really want to enable both chip-selects by default?
>
> On the rk3288 Lin Huang wrote:
> * It's assumed that most users of the SPI ports are using chip select
> 0. Thus the default pinctrl for the ports enables chip select 0
> (but not chip select 1 on ports that have it). If a board wants to
> use chip select 1 or wants a GPIO chip select the board should
> override the pinctrl (just like boards can override UART pinctrl if
> they have hardware flow control).
>
> Do we expect again mostly a use of cs0 or will in the major cases both chip-
> selects be needed?

Sound resonable.
In general, every cs and spi devices should be the one match one.

That should be resonable if we want to use chip select 1 or want a GPIO chip select the board should
override the pinctrl.

>> + num-cs = <2>;
>> + clocks =<&cru PCLK_SPI>, <&cru SCLK_SPI>;
>> + clock-names = "apb-pclk","spi_pclk";
>> + dmas = <&pdma 8>, <&pdma 9>;
>> + #dma-cells = <2>;
> What do you need #dma-cells for? This is not a dma-controller :-)

Fixed.

>
>
>> + dma-names = "tx", "rx";
>> + status = "disabled";
>> + };
>
> Also I'd suggest an ordering like:
>
> + spi: spi@20074000 {
> + compatible = "rockchip,rockchip-spi";
> + reg = <0x20074000 0x1000>;
> + interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
> + clocks =<&cru PCLK_SPI>, <&cru SCLK_SPI>;
> + clock-names = "apb-pclk","spi_pclk";
> + dmas = <&pdma 8>, <&pdma 9>;
> + dma-names = "tx", "rx";
> + num-cs = <2>;
> + pinctrl-names = "default";
> + pinctrl-0 = <&spi_txd &spi_rxd &spi_clk &spi_cs0 &spi_cs1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + status = "disabled";
> + };

Okay, I will remove the cs1/num-cs in here.

Thanks.

-
Caesar

>
> Heiko
>
> _______________________________________________
> Linux-rockchip mailing list
> Linux-rockchip@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-rockchip


--
Thanks,
Caesar

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