linux/Documentation/devicetree/bindings/cpufreq/imx-cpufreq-dt.txt
Leonard Crestez a02177a393 dt-bindings: imx-cpufreq-dt: Document opp-supported-hw usage
The interpretation of opp-supported-hw bits for imx-cpufreq-dt driver is
not very obvious so attempt to explain it.

There is no OF compat string associated.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-05-20 12:48:12 +05:30

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i.MX CPUFreq-DT OPP bindings
================================
Certain i.MX SoCs support different OPPs depending on the "market segment" and
"speed grading" value which are written in fuses. These bits are combined with
the opp-supported-hw values for each OPP to check if the OPP is allowed.
Required properties:
--------------------
For each opp entry in 'operating-points-v2' table:
- opp-supported-hw: Two bitmaps indicating:
- Supported speed grade mask
- Supported market segment mask
0: Consumer
1: Extended Consumer
2: Industrial
3: Automotive
Example:
--------
opp_table {
compatible = "operating-points-v2";
opp-1000000000 {
opp-hz = /bits/ 64 <1000000000>;
/* grade >= 0, consumer only */
opp-supported-hw = <0xf>, <0x3>;
};
opp-1300000000 {
opp-hz = /bits/ 64 <1300000000>;
opp-microvolt = <1000000>;
/* grade >= 1, all segments */
opp-supported-hw = <0xe>, <0x7>;
};
}