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

From: Fabrice Gasnier
Date: Thu Jun 29 2017 - 03:19:29 EST


On 06/28/2017 06:44 PM, Rob Herring wrote:
> 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.

Hi Rob,

Thanks for your answer. I'll update this in v3.

>
>>>> + 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.
>
I'll update this in v3.

Best Regards,
Fabrice
> Rob
>