Re: [PATCH v2 2/2] Documentation: devicetree: Add boost-frequency binding to list boost mode frequency

Sudeep Holla
2014-02-07T16:15:14Z

On 07/02/14 15:19, Thomas Abraham wrote:
> From: Thomas Abraham <thomas.ab@samsung.com>
>
> Add a new optional boost-frequency binding for specifying the frequencies
> usable in boost mode.
>
> Cc: Nishanth Menon <nm@ti.com>
> Cc: Lukasz Majewski <l.majewski@samsung.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Pawel Moll <pawel.moll@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
> Cc: Kumar Gala <galak@codeaurora.org>
> Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
> ---
> Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt | 11 +++++++++++
> 1 file changed, 11 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt
>
> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt
> new file mode 100644
> index 0000000..d925e38
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-boost.txt
> @@ -0,0 +1,11 @@
> +* Device tree binding for CPU boost frequency (aka over-clocking)
> +
> +Certain CPU's can be operated in optional 'boost' mode (or sometimes referred as
> +overclocking) in which the CPU can operate in frequencies beyond the normal
> +operating conditions.
> +
> +Optional Properties:
> +- boost-frequency: list of frequencies in KHz to be used only in boost mode.
> + This list should be a subset of frequencies listed in "operating-points"
> + property. Refer to Documentation/devicetree/bindings/power/opp.txt for
> + details about "operating-points" property.
>

Won't single entry for boost frequency suffice which would be the starting
frequency in the boost range. IWO will there be OPP list with frequencies:
A > B > C > D, but only B and C are boost frequency. That seems little odd,
unless it's some configuration chosen purely on software basis rather than
hardware. For me B marks the beginning of over-clocking.

Regards,
Sudeep