[PATCH v3 2/2] Documentation: devicetree: Add boost-frequency binding to list boost mode frequency
sudeep.holla at arm.com
Wed May 14 08:06:03 PDT 2014
On 14/05/14 02:03, Thomas Abraham wrote:
> From: Thomas Abraham <thomas.ab at samsung.com>
> Add a new optional boost-frequency binding for specifying the frequencies
> usable in boost mode.
> Cc: Nishanth Menon <nm at ti.com>
> Cc: Lukasz Majewski <l.majewski at samsung.com>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Pawel Moll <pawel.moll at arm.com>
> Cc: Mark Rutland <mark.rutland at arm.com>
> Cc: Ian Campbell <ijc+devicetree at hellion.org.uk>
> Cc: Kumar Gala <galak at codeaurora.org>
> Signed-off-by: Thomas Abraham <thomas.ab at samsung.com>
> .../devicetree/bindings/cpufreq/cpufreq-boost.txt | 11 +++++++++++
> 1 files changed, 11 insertions(+), 0 deletions(-)
> 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.
Though I understand the need of it, I think the binding is designed to suffice
the need of the boost frequency support in cpufreq.
Typically SoC would provide characteristics like under-drive(hits performance
but most energy efficient), nominal(highest sustained performance w/o any
external constraint like power, thermal) and over-drive(maximum performance but
not sustainable for long periods)
IMO the binding could represent these unique points on the curve instead.
More information about the linux-arm-kernel