On Wed, Aug 31, 2016 at 09:53:27PM -0500, Dave Gerlach wrote: > Add the device tree bindings document for the TI CPUFreq/OPP driver > on AM33xx, AM43xx, DRA7, and AM57 SoCs. The operating-points-v2 binding > allows us to provide an opp-supported-hw property for each OPP to define > when it is available. This driver is responsible for reading and parsing > registers to determine which OPPs can be selectively enabled based > on the specific SoC in use by matching against the opp-supported-hw > data. Sorry, for the delay. Missed this somehow. > > Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx> > --- > v1->v2: > - Dropped all driver/linux specific documentation > - Fixed some typos > - Add new compatibles for each SoC family to match against > - Switched to use am335x example to better demonstrate field one of > opp-supported-hw. > > .../devicetree/bindings/cpufreq/ti-cpufreq.txt | 130 +++++++++++++++++++++ > 1 file changed, 130 insertions(+) > create mode 100644 Documentation/devicetree/bindings/cpufreq/ti-cpufreq.txt > > diff --git a/Documentation/devicetree/bindings/cpufreq/ti-cpufreq.txt b/Documentation/devicetree/bindings/cpufreq/ti-cpufreq.txt > new file mode 100644 > index 000000000000..6276ae494121 > --- /dev/null > +++ b/Documentation/devicetree/bindings/cpufreq/ti-cpufreq.txt > @@ -0,0 +1,130 @@ > +TI CPUFreq and OPP bindings > +================================ > + > +Certain TI SoCs, like those in the am335x, am437x, am57xx, and dra7xx > +families support different OPPs depending on the silicon variant in use. > +The ti_cpufreq driver can use revision and an efuse value from the SoC to > +provide the OPP framework with supported hardware information. This is > +used to determine which OPPs from the operating-points-v2 table get enabled > +when it is parsed by the OPP framework. > + > +Required properties: > +-------------------- > +In 'cpus' nodes: > +- operating-points-v2: Phandle to the operating-points-v2 table to use. > +- ti,syscon-efuse: Syscon phandle, offset to efuse register, efuse register > + mask, and efuse register shift to get the relevant bits > + that describe OPP availability. > +- ti,syscon-rev: Syscon and offset used to look up revision value on SoC. These have nothing to do with a cpu, so they don't belong here. Maybe the first is a property of an OPP table, but the second certainly is not. > + > +In 'operating-points-v2' table: > +- compatible: Should be > + - 'operating-points-v2-ti-am3352-cpu' for am335x SoCs > + - 'operating-points-v2-ti-am4372-cpu' for am43xx SoCs > + - 'operating-points-v2-ti-dra7-cpu' for dra7xx/am57xx SoCs > + > +- opp-supported-hw: Two bitfields indicating: > + 1. Which revision of the SoC the OPP is supported by > + 2. Which eFuse bits indicate this OPP is available I tend to think you should handle this with kernel code (bootloader really) fixing up the OPP table as necessary rather than putting in DT. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
