On 30.04.2019 20:35, Aisheng Dong wrote:
> MX8QM and MX8QXP LPCG Clocks are mostly the same except they may reside
> in different subsystems across CPUs and also vary a bit on the availability.
>
> Same as SCU clock, we want to move the clock definition into device tree
> which can fully decouple the dependency of Clock ID definition from device
> tree and make us be able to write a fully generic lpcg clock driver.
>
> And we can also use the existence of clock nodes in device tree to address
> the device and clock availability differences across different SoCs.
>
> diff --git a/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt b/Documentation/devicetree/bindings/clock/imx8qxp-lpcg.txt
>
> Required properties:
> +- compatible: Should be one of:
> + "fsl,imx8qxp-lpcg"
> + "fsl,imx8qm-lpcg" followed by "fsl,imx8qxp-lpcg".
> +- reg: Address and length of the register set.
> +- #clock-cells: Should be 1. One LPCG supports multiple clocks.
> +- clocks: Input parent clocks phandle array for each clock.
> +- bit-offset: An integer array indicating the bit offset for each clock.
> +- hw-autogate: Boolean array indicating whether supports HW autogate for
> + each clock.
> +- clock-output-names: Shall be the corresponding names of the outputs.
> + NOTE this property must be specified in the same order
> + as the clock bit-offset and hw-autogate property.
Splitting the LPCG areas is good but describing "bit-offset" and similar
inside devicetree seems excessively generic.
Perhaps we could have many smaller imx8qxp-lpcg-sdhc, imx8qxp-lpcg-enet
etc where the actual clks inside each node are still defined in driver code.
> usdhc1: mmc@5b010000 {
> @@ -44,8 +66,8 @@ usdhc1: mmc@5b010000 {
> interrupt-parent = <&gic>;
> interrupts = <GIC_SPI 232 IRQ_TYPE_LEVEL_HIGH>;
> reg = <0x5b010000 0x10000>;
> - clocks = <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_IPG_CLK>,
> - <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_PER_CLK>,
> - <&conn_lpcg IMX8QXP_CONN_LPCG_SDHC0_HCLK>;
> + clocks = <&sdhc0_lpcg 1>,
> + <&sdhc0_lpcg 0>,
> + <&sdhc0_lpcg 2>;
This is less readable, can't we keep symbolic constants?
