[PATCH 3/3] cpufreq: Add a generic cpufreq-cpu0 driver

Shawn Guo shawn.guo at linaro.org
Tue Jul 31 00:20:52 EDT 2012

On Mon, Jul 30, 2012 at 07:53:45PM +0100, Mark Brown wrote:
> Quite honestly this seems totally unrealistic for the majority of users,

I doubt that.  Searching drivers/cpufreq folder, I can see there are
several cpufreq drivers scaling voltage with regulator API, but none
of them is calling regulator_set_voltage_time to find voltage latency.
That said, all these users are specify transition latency on their own.

> especially given the very poor documentation for this stuff which SoC
> vendors typically provide.  It's a reasonable amount of work to go back
> and figure this stuff out (especially given that it should be varying
> depending on the transition in question), and it's going to give us a
> bunch of magic numbers in people's bindings.
There will be only one magic number, and it can easily become "magic"
with some comments put there.

> No, add a new API.
Is the following patch what you are ordering here?

diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index da339fd..bfd3cfb 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -352,4 +352,11 @@ static inline void regulator_set_drvdata(struct regulator *regulator,


+static inline int regulator_set_voltage_tolerance(struct regulator *regulator,
+                                                 int new_uV, int tol_uV)
+       return regulator_set_voltage(regulator,
+                                    new_uV - tol_uV, new_uV + tol_uV);


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