[PATCH 1/2] dt-bindings: mediatek: Add MT8173 cpufreq driver binding
Pi-Cheng Chen
pi-cheng.chen at linaro.org
Wed Jun 24 01:57:29 PDT 2015
On Wed, Jun 24, 2015 at 9:06 AM, Viresh Kumar <viresh.kumar at linaro.org> wrote:
> Adding Mike's new email address..
>
> On 23-06-15, 23:31, Pi-Cheng Chen wrote:
>> On Mon, Jun 8, 2015 at 8:29 PM, Pi-Cheng Chen <pi-cheng.chen at linaro.org> wrote:
>> > This patch adds device tree binding document for MT8173 cpufreq driver.
>> >
>> > Signed-off-by: Pi-Cheng Chen <pi-cheng.chen at linaro.org>
>> > ---
>> > .../devicetree/bindings/cpufreq/cpufreq-mt8173.txt | 127 +++++++++++++++++++++
>> > 1 file changed, 127 insertions(+)
>> > create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-mt8173.txt
>> >
>> > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-mt8173.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-mt8173.txt
>> > new file mode 100644
>> > index 0000000..7708a65
>> > --- /dev/null
>> > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-mt8173.txt
>> > @@ -0,0 +1,127 @@
>> > +
>> > +Mediatek MT8173 cpufreq driver
>> > +-------------------
>
> Few more ---- required.
Will add it.
>
>> > +
>> > +Mediatek MT8173 cpufreq driver for CPU frequency scaling.
>> > +
>> > +Required properties:
>> > +- clocks: A list of phandle + clock-specifier pairs for the clocks listed in clock names.
>> > +- clock-names: Should contain the following:
>> > + "cpu" - The multiplexer for clock input of CPU cluster.
>> > + "intermediate" - A parent of "cpu" clock which is used as "intermediate" clock
>> > + source (usually MAINPLL) when the original CPU PLL is under
>> > + transition and not stable yet.
>
> These belong to Mike.
>
>> > +- operating-points: Table of frequencies and voltage CPU could be transitioned into,
>> > + Frequency should be in KHz units and voltage should be in microvolts.
>
> That's not complete. You should just mention the path to opp bindings
> here. And that's it.
Yes. So should it be:
- operating-points: Refer to
Documentation/devicetree/bindings/power/opp.txt
for details
?
>
>> > +- proc-supply: Regulator for Vproc of CPU cluster.
>> > +
>> > +Optional properties:
>> > +- sram-supply: Regulator for Vsram of CPU cluster. When present, the cpufreq driver
>> > + needs to do "voltage trace" to step by step scale up/down Vproc and
>> > + Vsram to fit SoC specific needs. When absent, the voltage scaling
>> > + flow is handled by hardware, hence no software "voltage trace" is
>> > + needed.
>> > +
>> > +Example:
>> > +--------
>> > + cpu0: cpu at 0 {
>> > + device_type = "cpu";
>> > + compatible = "arm,cortex-a53";
>> > + reg = <0x000>;
>> > + enable-method = "psci";
>> > + cpu-idle-states = <&CPU_SLEEP_0>;
>> > + clocks = <&infracfg CLK_INFRA_CA53SEL>,
>> > + <&apmixedsys CLK_APMIXED_MAINPLL>;
>> > + clock-names = "cpu", "intermediate";
>> > + operating-points = <
>> > + 507000 859000
>> > + 702000 908000
>> > + 1001000 983000
>> > + 1105000 1009000
>> > + 1183000 1028000
>> > + 1404000 1083000
>> > + 1508000 1109000
>> > + 1573000 1125000
>> > + >;
>> > + };
>> > +
>> > + cpu1: cpu at 1 {
>> > + device_type = "cpu";
>> > + compatible = "arm,cortex-a53";
>> > + reg = <0x001>;
>> > + enable-method = "psci";
>> > + cpu-idle-states = <&CPU_SLEEP_0>;
>> > + clocks = <&infracfg CLK_INFRA_CA53SEL>,
>> > + <&apmixedsys CLK_APMIXED_MAINPLL>;
>> > + clock-names = "cpu", "intermediate";
>> > + operating-points = <
>> > + 507000 859000
>> > + 702000 908000
>> > + 1001000 983000
>> > + 1105000 1009000
>> > + 1183000 1028000
>> > + 1404000 1083000
>> > + 1508000 1109000
>> > + 1573000 1125000
>> > + >;
>> > + };
>> > +
>> > + cpu2: cpu at 100 {
>> > + device_type = "cpu";
>> > + compatible = "arm,cortex-a57";
>> > + reg = <0x100>;
>> > + enable-method = "psci";
>> > + cpu-idle-states = <&CPU_SLEEP_0>;
>> > + clocks = <&infracfg CLK_INFRA_CA57SEL>,
>> > + <&apmixedsys CLK_APMIXED_MAINPLL>;
>> > + clock-names = "cpu", "intermediate";
>> > + operating-points = <
>> > + 507000 828000
>> > + 702000 867000
>> > + 1001000 927000
>> > + 1209000 968000
>> > + 1404000 1007000
>> > + 1612000 1049000
>> > + 1807000 1089000
>> > + 1989000 1125000
>> > + >;
>> > + };
>> > +
>> > + cpu3: cpu at 101 {
>> > + device_type = "cpu";
>> > + compatible = "arm,cortex-a57";
>> > + reg = <0x101>;
>> > + enable-method = "psci";
>> > + cpu-idle-states = <&CPU_SLEEP_0>;
>> > + clocks = <&infracfg CLK_INFRA_CA57SEL>,
>> > + <&apmixedsys CLK_APMIXED_MAINPLL>;
>> > + clock-names = "cpu", "intermediate";
>> > + operating-points = <
>> > + 507000 828000
>> > + 702000 867000
>> > + 1001000 927000
>> > + 1209000 968000
>> > + 1404000 1007000
>> > + 1612000 1049000
>> > + 1807000 1089000
>> > + 1989000 1125000
>> > + >;
>> > + };
>
> I remember Mark Rutland asking you about the replicated stuff for all
> CPUs, but happened to his comments later on ? Were you asked to put
> these for all the CPUs ?
I was not asked to do so and I didn't get any further comments for last
series from then. But I think duplicating these properties for all CPU nodes
helps in the cases all CPUs in a cluster are unplugged and plugged in different
order and it's more properly descriptive for the real hardware. Therefore I
replicate them for all CPUs.
Thanks for your reviewing.
Pi-Cheng
>
> --
> viresh
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