From a02177a39344b643dccfa3b18fa5c1fc4984e1e5 Mon Sep 17 00:00:00 2001 From: Leonard Crestez Date: Mon, 13 May 2019 11:01:39 +0000 Subject: 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 Signed-off-by: Leonard Crestez Signed-off-by: Viresh Kumar --- .../devicetree/bindings/cpufreq/imx-cpufreq-dt.txt | 37 ++++++++++++++++++++++ 1 file changed, 37 insertions(+) create mode 100644 Documentation/devicetree/bindings/cpufreq/imx-cpufreq-dt.txt (limited to 'Documentation/devicetree/bindings/cpufreq') diff --git a/Documentation/devicetree/bindings/cpufreq/imx-cpufreq-dt.txt b/Documentation/devicetree/bindings/cpufreq/imx-cpufreq-dt.txt new file mode 100644 index 000000000000..87bff5add3f9 --- /dev/null +++ b/Documentation/devicetree/bindings/cpufreq/imx-cpufreq-dt.txt @@ -0,0 +1,37 @@ +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>; + }; +} -- cgit