Dear Viresh, Sorry for the late reply. On Mon, 2019-08-19 at 19:18 +0800, Viresh Kumar wrote: > On 13-08-19, 21:31, Andrew-sh.Cheng wrote: > > From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > > > On some SoCs the Adaptive Voltage Scaling (AVS) technique is > > employed to optimize the operating voltage of a device. At a > > given frequency, the hardware monitors dynamic factors and either > > makes a suggestion for how much to adjust a voltage for the > > current frequency, or it automatically adjusts the voltage > > without software intervention. Add an API to the OPP library for > > the former case, so that AVS type devices can update the voltages > > for an OPP when the hardware determines the voltage should > > change. The assumption is that drivers like CPUfreq or devfreq > > will register for the OPP notifiers and adjust the voltage > > according to suggestions that AVS makes. > > > > This patch is devired from [1] submitted by Stephen. > > [1] https://lore.kernel.org/patchwork/patch/599279/ > > > > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx> > > Signed-off-by: Roger Lu <roger.lu@xxxxxxxxxxxx> > > --- > > drivers/opp/core.c | 63 ++++++++++++++++++++++++++++++++++++++++++++++++++ > > include/linux/pm_opp.h | 11 +++++++++ > > 2 files changed, 74 insertions(+) > > > > diff --git a/drivers/opp/core.c b/drivers/opp/core.c > > index c094d5d20fd7..407a07f29b12 100644 > > --- a/drivers/opp/core.c > > +++ b/drivers/opp/core.c > > @@ -2054,6 +2054,69 @@ static int _opp_set_availability(struct device *dev, unsigned long freq, > > } > > > > /** > > + * dev_pm_opp_adjust_voltage() - helper to change the voltage of an OPP > > + * @dev: device for which we do this operation > > + * @freq: OPP frequency to adjust voltage of > > + * @u_volt: new OPP voltage > > + * > > + * Return: -EINVAL for bad pointers, -ENOMEM if no memory available for the > > + * copy operation, returns 0 if no modifcation was done OR modification was > > + * successful. > > + */ > > +int dev_pm_opp_adjust_voltage(struct device *dev, unsigned long freq, > > + unsigned long u_volt) > > Can you please update this to take a triplet instead ? That is what we are > storing in OPP core now a days. I've studied opp/core.c and still don't know meaning of triplet here. Could you give me more hints (reference API?) about how to take a triplet instead? Thanks in advance.
