On Thu, Apr 06, 2017 at 09:57:09AM +0100, Jon Hunter wrote: > > On 05/04/17 15:13, Laxman Dewangan wrote: > > In some of NVIDIA Tegra's platform, PWM controller is used to > > control the PWM controlled regulators. PWM signal is connected to > > the VID pin of the regulator where duty cycle of PWM signal decide > > the voltage level of the regulator output. > > > > The tristate (high impedance of PWM pin form Tegra) also define > > one of the state of PWM regulator which needs to be configure in > > suspend state of system. > > > > Add DT binding details to provide the pin configuration state > > from PWM and pinctrl DT node in suspend and active state of > > the system. > > > > Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx> > > --- > > .../devicetree/bindings/pwm/nvidia,tegra20-pwm.txt | 43 ++++++++++++++++++++++ > > 1 file changed, 43 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt > > index b4e7377..145c323 100644 > > --- a/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt > > +++ b/Documentation/devicetree/bindings/pwm/nvidia,tegra20-pwm.txt > > @@ -19,6 +19,19 @@ Required properties: > > - reset-names: Must include the following entries: > > - pwm > > > > +Optional properties: > > +============================ > > +In some of the interface like PWM based regualator device, it is required > > +to configure the pins diffrently in different states, specially in suspend > > s/diffrently/differently > s/specially/especially > > > +state of the system. The configuration of pin is provided via the pinctrl > > +DT node as detailed in the pinctrl DT binding document > > + Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt > > + > > +The PWM node will have following optional properties. > > +pinctrl-names: Pin state names. Must be "suspend" and "resume". > > Why not just use the pre-defined names here? There is a pre-defined name > for "default", "idle" and "sleep" and then you can use the following > APIs and avoid the lookup of the state ... > > pinctrl_pm_select_default_state() > pinctrl_pm_select_idle_state() > pinctrl_pm_select_sleep_state() > > Note for i2c [0][1], I used "default" as the active/on state (which I > know is not that descriptive) and then used 'idle' as the suspended > state. This way we don't need any custom names. Agreed, I think that's how these states are meant to be used. Thierry
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