Re: [PATCH 1/1] Add PPD device tree

[Fabien Lahoudere]

Hello,

Thanks for your comments

On 05/08/2016 15:39, Mark Rutland wrote:
> On Fri, Aug 05, 2016 at 03:31:25PM +0200, Fabien Lahoudere wrote:
> > +/*
> > + * Hardware uses CKO2 at 24MHz at several places. Set the parent clock of
> > + * CKO2 to OSC.
> > + */
> > +#define CKO2_CONFIGURATION \
> > +	clock-frequency = <24000000>; \
> > +	clocks = <&clks IMX5_CLK_CKO2>; \
> > +	assigned-clocks = <&clks IMX5_CLK_CKO2_SEL>, <&clks IMX5_CLK_OSC>; \
> > +	assigned-clock-parents = <&clks IMX5_CLK_OSC>
>
> This makes the DT harder to read.
>
> Please place these explicitly where used.
>
> > +
> > +/ {
> > +	model = "Freescale i.MX53 CPUV0 PPD rev6";
> > +	compatible = "fsl,imx53-ppd", "fsl,imx53";
> > +
> > +	aliases {
> > +		spi0 = &cspi;
> > +		spi1 = &ecspi1;
> > +		spi2 = &ecspi2;
> > +	};
> > +
> > +	chosen {
> > +		stdout-path = &uart1;
> > +	};
>
> It would be good if you could also define the rate, using an alias if
> necessary.
>
> > +
> > +	memory {
> > +		reg = <0x70000000 0x20000000>,
> > +		      <0xb0000000 0x20000000>;
> > +	};
> > +
> > +	clocks {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +
> > +		cko2_11M: sgtl_clock_cko2 {
> > +			compatible = "fixed-clock";
> > +			#clock-cells = <0>;
> > +			clock-frequency = <11289600>;
> > +		};
> > +	};
>
> Get rid of the clocks node, and place the clock directly under the root
> node.
>
> > +
> > +	regulators {
> > +		compatible = "simple-bus";
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +
> > +		reg_sgtl5k: regulator@0 {
> > +			compatible = "regulator-fixed";
> > +			reg = <0>;
> > +			regulator-name = "reg-sgtl5k";
> > +			regulator-min-microvolt = <3300000>;
> > +			regulator-max-microvolt = <3300000>;
> > +			regulator-always-on;
> > +		};
>
> Likewise for these. Get rid of the regulators container node and place
> these directly under the root node.
>
> Please don't make fake up reg and unit-address values. Just suffix the
> node name, e.g. regulator-sgtl5k.

Ok for all above.

> > +&ecspi1 {
> > +	pinctrl-names = "default";
> > +	pinctrl-0 = <&pinctrl_ecspi1>;
> > +	fsl,spi-num-chipselects = <4>;
> > +	/* Fake this GPIO, this has special handling in userspace. */
>
> NAK. The DT should reflect reality, and should not be specific to a
> given userspace.
>
> > +	cs-gpios = <&gpio5 1 GPIO_ACTIVE_LOW
> > +		    &gpio4 10 GPIO_ACTIVE_LOW
> > +		    &gpio4 11 GPIO_ACTIVE_LOW
> > +		    &gpio4 12 GPIO_ACTIVE_LOW>;
> > +	status = "okay";
> > +
> > +	spidev0: spi@0 {
> > +		compatible = "spidev";
> > +		reg = <0>;
> > +		spi-max-frequency = <1000000>;
> > +		status = "okay";
> > +	};
> > +
> > +	spidev1: spi@1 {
> > +		compatible = "spidev";
> > +		reg = <1>;
> > +		spi-max-frequency = <1000000>;
> > +		status = "okay";
> > +	};
> > +
> > +	spidev2: spi@2 {
> > +		compatible = "spidev";
> > +		reg = <2>;
> > +		spi-max-frequency = <1000000>;
> > +		status = "okay";
> > +	};
> > +
> > +	spidev3: spi@3 {
> > +		compatible = "spidev";
> > +		reg = <3>;
> > +		spi-max-frequency = <1000000>;
> > +		status = "okay";
> > +	};
> > +};
>
> What are these SPI devices?
>
> Please fully describe them, with a complete compatible list.
>
> Thanks,
> Mark.
I understand what you mean and I agree but spidev0 and spidev1 
communicate with another micro with an OS (cortex M4) so it is ok if I 
add 'compatible = "fsl,mk20fn1m0vmd12"' in the dts and in spidev.c ?

The 2 other devices are EXAR xra1403 (gpio controller).

--
Fabien Lahoudere
Collabora Ltd.