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

From: Mark Rutland
Date: Fri Aug 05 2016 - 09:40:16 EST


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.

> +&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.