[PATCH] bcm2835: Add Raspberry Pi CPU frequency control to the device tree

Stephen Warren swarren at wwwdotorg.org
Tue Oct 20 20:00:18 PDT 2015

On 10/11/2015 01:46 PM, Lubomir Rintel wrote:
> This adds a device tree binding for Broadcom BCM2834 CPU frequency control
> driven via Raspberry Pi VideoCore 4 firmware interface.

Oh I see; that DT binding was sent as a separate patch rather than part
of the series...

DT bindings patches need to be sent to the people/lists in the following

M:      Rob Herring <robh+dt at kernel.org>
M:      Pawel Moll <pawel.moll at arm.com>
M:      Mark Rutland <mark.rutland at arm.com>
M:      Ian Campbell <ijc+devicetree at hellion.org.uk>
M:      Kumar Gala <galak at codeaurora.org>
L:      devicetree at vger.kernel.org

> diff --git a/Documentation/devicetree/bindings/cpufreq/raspberrypi,bcm2835-cpufreq.txt b/Documentation/devicetree/bindings/cpufreq/raspberrypi,bcm2835-cpufreq.txt
> new file mode 100644
> index 0000000..eb126d3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cpufreq/raspberrypi,bcm2835-cpufreq.txt
> @@ -0,0 +1,13 @@
> +Raspberry Pi Broadcom BCM2835 CPU frequency control
> +
> +Required properties:
> +
> +- compatible : should be "raspberrypi,bcm2835-cpufreq"
> +- firmware : the Raspberry Pi firmware node

It'd be best practice to mention the filename of the binding that
defines the firmware. For example:

- firmware : phandle of the Raspberry Pi firmware node, as defined in

That said, I'm not convinced cpufreq scaling should rely on the firmware
directly, but instead should use the clock API to manipulate the clock.

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