Re: [PATCH v2 1/8] dt-bindings: mfd: Add STM32 LPTimer binding

From: Rob Herring
Date: Wed Jun 28 2017 - 12:44:23 EST


On Tue, Jun 27, 2017 at 10:57:32AM +0200, Fabrice Gasnier wrote:
> On 06/26/2017 08:07 PM, Rob Herring wrote:
> > On Wed, Jun 21, 2017 at 04:30:08PM +0200, Fabrice Gasnier wrote:
> >> Add documentation for STMicroelectronics STM32 Low-Power Timer binding.
> >>
> >> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
> >> ---
> >> Changes in v2:
> >> - Lee's comments: s/Low Power/Low-Power/, remove 0x in example, improve
> >> properties descriptions
> >> ---
> >> .../devicetree/bindings/mfd/stm32-lptimer.txt | 48 ++++++++++++++++++++++
> >> 1 file changed, 48 insertions(+)
> >> create mode 100644 Documentation/devicetree/bindings/mfd/stm32-lptimer.txt
> >>
> >> diff --git a/Documentation/devicetree/bindings/mfd/stm32-lptimer.txt b/Documentation/devicetree/bindings/mfd/stm32-lptimer.txt
> >> new file mode 100644
> >> index 0000000..af859c8
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/mfd/stm32-lptimer.txt
> >> @@ -0,0 +1,48 @@
> >> +STMicroelectronics STM32 Low-Power Timer
> >> +
> >> +The STM32 Low-Power Timer (LPTIM) is a 16-bit timer that provides several
> >> +functions:
> >> +- PWM output (with programmable prescaler, configurable polarity)
> >> +- Quadrature encoder, counter
> >> +- Trigger source for STM32 ADC/DAC (LPTIM_OUT)
> >> +
> >> +Required properties:
> >> +- compatible: Must be "st,stm32-lptimer".
> >> +- reg: Offset and length of the device's register set.
> >> +- clocks: Phandle to the clock used by the LP Timer module.
> >> +- clock-names: Must be "mux".
> >> +- #address-cells: Should be '<1>'.
> >> +- #size-cells: Should be '<0>'.
> >> +
> >> +Optional subnodes:
> >> +- pwm: See ../pwm/pwm-stm32-lp.txt
> >> +- counter: See ../iio/timer/stm32-lptimer-cnt.txt
> >> +- trigger: See ../iio/timer/stm32-lptimer-trigger.txt
> >> +
> >> +Example:
> >> +
> >> + lptimer1: lptimer@40002400 {
> >
> > timer@...
>
> Hi Rob,
>
> I initially put "lptimer" here to distinguish Low-Power Timer hardware
> from other "timers" hardware that can be found also on stm32 devices.
> I'd prefer to keep it, is it sensible from your point of view ?
> Please advise.

Node names are supposed to be the class of device (e.g. ethernet,
serial, etc.), not the specific device. The compatible is what
distinguishes it from other timers.

> >> + compatible = "st,stm32-lptimer";
> >> + reg = <0x40002400 0x400>;
> >> + clocks = <&timer_clk>;
> >> + clock-names = "mux";
> >> + #address-cells = <1>;
> >> + #size-cells = <0>;
> >> +
> >> + pwm {
> >> + compatible = "st,stm32-pwm-lp";
> >> + pinctrl-names = "default";
> >> + pinctrl-0 = <&lppwm1_pins>;
> >> + };
> >> +
> >> + trigger@0 {
> >> + compatible = "st,stm32-lptimer-trigger";
> >> + reg = <0>;
> >
> > Is there more than 1?
>
> reg identifies trigger hardware block.

Okay, the trigger patch needs to be reworded.

Rob