On Fri, Mar 14, 2014 at 2:25 PM, Dave Gerlach <d-gerlach@xxxxxx> wrote: > Driver to read from a register and depending on either set bits or > a specific known selectively enable or disable OPPs based on DT node. > > Can support opp-modifier-reg-bit where single bits within the register > determine the availability of an OPP or opp-modifier-reg-val where a > certain value inside the register or a portion of it determine what the > maximum allowed OPP is. > > The driver expects a device that has already has its OPPs loaded > and then will disable the OPPs not matching the criteria specified in > the opp-modifier table. > > Signed-off-by: Dave Gerlach <d-gerlach@xxxxxx> > --- > .../devicetree/bindings/power/opp-modifier.txt | 111 +++++++++ > drivers/power/opp/Makefile | 1 + > drivers/power/opp/opp-modifier-reg.c | 259 +++++++++++++++++++++ > 3 files changed, 371 insertions(+) > create mode 100644 Documentation/devicetree/bindings/power/opp-modifier.txt > create mode 100644 drivers/power/opp/opp-modifier-reg.c > > diff --git a/Documentation/devicetree/bindings/power/opp-modifier.txt b/Documentation/devicetree/bindings/power/opp-modifier.txt > new file mode 100644 > index 0000000..af8a2e9 > --- /dev/null > +++ b/Documentation/devicetree/bindings/power/opp-modifier.txt > @@ -0,0 +1,111 @@ > +* OPP-Modifier - opp modifier to selectively enable operating points > + > +Many SoCs that have selectively modifiable OPPs can specify > +all available OPPs in their operating-points listing and then define > +opp_modifiers to enable or disable the OPPs that are actually available > +on the specific hardware. > + > +* OPP Modifier Provider Uggg. Please stop designing around the current OPP binding which has the problem that the OPP table is not extensible to add more data. Define a new OPP binding that solves these problems. This is at least the 3rd OPP related binding addition I've seen recently. But I wouldn't spend a lot of effort on a new OPP binding just to add the functionality you are adding here because I don't like the whole concept in general. This might be a common way to determine valid OPPs on TI chips, but I think it is too low level and I don't want to see bindings for every different possible way. Just add platform code to do the OPP setup you need. Frankly, I prefer the bootloader/firmware fixup the OPP table approach mentioned in the cpufreq-cpu0 thread. Somewhat less desirable, but the kernel could do the fixups as well (via of_update_property). 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
