Re: [PATCH 2/2] cpufreq: cpufreq-cpu0: provide compatibility stringfor DT matchup

From: Shawn Guo
Date: Tue Mar 12 2013 - 03:58:25 EST


Copied devicetree-discuss list.

On Mon, Mar 11, 2013 at 06:05:30PM -0500, Nishanth Menon wrote:
> commit 5553f9e (cpufreq: instantiate cpufreq-cpu0 as a platform_driver)
> now forces platform device to be registered for allowing cpufreq-cpu0
> to be used by SoCs. example: drivers/cpufreq/highbank-cpufreq.c
>
> However, for SoCs that wish to link up using device tree, instead
> of platform device, provide compatibility string match:
> compatible = "cpufreq,cpu0";

This compatible is merely added for asking DT core code to populate
a platform_device for cpufreq driver. It's not describing
hardware/cpus, and it does not belong to device tree.

Shawn

>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx>
> Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> Cc: Shawn Guo <shawn.guo@xxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: cpufreq@xxxxxxxxxxxxxxx
> Cc: linux-pm@xxxxxxxxxxxxxxx
> Cc: linux-omap@xxxxxxxxxxxxxxx
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
> ---
> .../devicetree/bindings/cpufreq/cpufreq-cpu0.txt | 3 +++
> drivers/cpufreq/cpufreq-cpu0.c | 6 ++++++
> 2 files changed, 9 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> index f180963..a5699f0 100644
> --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> @@ -10,6 +10,8 @@ under node /cpus/cpu@0.
> Required properties:
> - operating-points: Refer to Documentation/devicetree/bindings/power/opp.txt
> for details
> +- compatible: if platform_device is *not* used, should be:
> + "cpufreq,cpu0"
>
> Optional properties:
> - clock-name: If the clock is not converted to device tree, then describe
> @@ -24,6 +26,7 @@ Examples:
> cpus {
> #address-cells = <1>;
> #size-cells = <0>;
> + compatible = "cpufreq,cpu0";
>
> cpu@0 {
> compatible = "arm,cortex-a9";
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> index 28223c9..a6f0a9b 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -277,9 +277,15 @@ static int cpu0_cpufreq_remove(struct platform_device *pdev)
> return 0;
> }
>
> +static struct of_device_id of_cpu0_cpufreq_match[] = {
> + { .compatible = "cpufreq,cpu0", },
> + { /* end */ }
> +};
> +
> static struct platform_driver cpu0_cpufreq_platdrv = {
> .driver = {
> .name = "cpufreq-cpu0",
> + .of_match_table = of_cpu0_cpufreq_match,
> .owner = THIS_MODULE,
> },
> .probe = cpu0_cpufreq_probe,
> --
> 1.7.9.5
>

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/