Re: [PATCH 1/2] arm64: dts: sun50i: H6: Add SPI controllers nodes and pinmuxes

[Andre Przywara <andre.przywara-5wv7dgnIgG8@public.gmane.org>]

On Wed, 8 Jan 2020 12:34:48 +0100
Emmanuel Vadot <manu-xXdDKFdH5B3kFDPD4ZthVA@public.gmane.org> wrote:

Hi Emmanuel,

> On Wed,  8 Jan 2020 10:10:05 +0000
> Andre Przywara <andre.przywara-5wv7dgnIgG8@public.gmane.org> wrote:
> 
> > The Allwinner H6 SoC contains two SPI controllers similar to the H3/A64,
> > but with the added capability of 3-wire and 4-wire operation modes.
> > For now the driver does not support those, but the SPI registers are
> > fully backwards-compatible, just adding bits and registers which were
> > formerly reserved. So we can use the existing driver for the "normal" SPI
> > modes, for instance to access the SPI NOR flash soldered on the PineH64
> > board.
> > We use an H6 specific compatible string in addition to the existing H3
> > string, so when the driver later gains Quad SPI support, it should work
> > automatically without any DT changes.
> > 
> > Tested by accessing the SPI flash on a Pine H64 board (SPI0), also
> > connecting another SPI flash to the SPI1 header pins.
> > 
> > Signed-off-by: Andre Przywara <andre.przywara-5wv7dgnIgG8@public.gmane.org>
> > ---
> >  arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi | 54 ++++++++++++++++++++
> >  1 file changed, 54 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> > index 3329283e38ab..40835850893e 100644
> > --- a/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> > +++ b/arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi
> > @@ -338,6 +338,30 @@
> >  				bias-pull-up;
> >  			};
> >  
> > +			/omit-if-no-ref/  
> 
>  That would prevent users to use an overlay and use those pins, is that
> something that we want ? I'm not sure that the space saved by those are
> useful.

Me neither ;-), but Maxime asked for it before, and it doesn't really hurt.

For overlays: if a .dtb is compiled with support for overlays (-@ to generate symbols), this tag is ignored, and the nodes stay in the .dtb, regardless of being referenced or not. Just confirmed by trying this.

Cheers,
Andre.

> 
>  Cheers,
> 
> > +			spi0_pins: spi0-pins {
> > +				pins = "PC0", "PC2", "PC3";
> > +				function = "spi0";
> > +			};
> > +
> > +			/omit-if-no-ref/
> > +			spi0_cs_pin: spi0-cs-pin {
> > +				pins = "PC5";
> > +				function = "spi0";
> > +			};
> > +
> > +			/omit-if-no-ref/
> > +			spi1_pins: spi1-pins {
> > +				pins = "PH4", "PH5", "PH6";
> > +				function = "spi1";
> > +			};
> > +
> > +			/omit-if-no-ref/
> > +			spi1_cs_pin: spi1-cs-pin {
> > +				pins = "PH3";
> > +				function = "spi1";
> > +			};
> > +
> >  			spdif_tx_pin: spdif-tx-pin {
> >  				pins = "PH7";
> >  				function = "spdif";
> > @@ -504,6 +528,36 @@
> >  			#size-cells = <0>;
> >  		};
> >  
> > +		spi0: spi@5010000 {
> > +			compatible = "allwinner,sun50i-h6-spi",
> > +				     "allwinner,sun8i-h3-spi";
> > +			reg = <0x05010000 0x1000>;
> > +			interrupts = <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;
> > +			clocks = <&ccu CLK_BUS_SPI0>, <&ccu CLK_SPI0>;
> > +			clock-names = "ahb", "mod";
> > +			dmas = <&dma 22>, <&dma 22>;
> > +			dma-names = "rx", "tx";
> > +			resets = <&ccu RST_BUS_SPI0>;
> > +			status = "disabled";
> > +			#address-cells = <1>;
> > +			#size-cells = <0>;
> > +		};
> > +
> > +		spi1: spi@5011000 {
> > +			compatible = "allwinner,sun50i-h6-spi",
> > +				     "allwinner,sun8i-h3-spi";
> > +			reg = <0x05011000 0x1000>;
> > +			interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
> > +			clocks = <&ccu CLK_BUS_SPI1>, <&ccu CLK_SPI1>;
> > +			clock-names = "ahb", "mod";
> > +			dmas = <&dma 23>, <&dma 23>;
> > +			dma-names = "rx", "tx";
> > +			resets = <&ccu RST_BUS_SPI1>;
> > +			status = "disabled";
> > +			#address-cells = <1>;
> > +			#size-cells = <0>;
> > +		};
> > +
> >  		emac: ethernet@5020000 {
> >  			compatible = "allwinner,sun50i-h6-emac",
> >  				     "allwinner,sun50i-a64-emac";
> > -- 
> > 2.17.1