[PATCH 2/2] DT: pwm: Add NXP LPC18xx PWM/SCT binding documentation

[Ezequiel Garcia]

On 28 July 2015 at 19:37, Joachim  Eastwood <manabian at gmail.com> wrote:
> On 27 July 2015 at 06:45, Ariel D'Alessandro <ariel at vanguardiasur.com.ar> wrote:
>> Add the devicetree binding document for NXP LPC18xx PWM/SCT.
>>
>> Signed-off-by: Ariel D'Alessandro <ariel at vanguardiasur.com.ar>
>> ---
>>  .../devicetree/bindings/pwm/lpc1850-pwm.txt          | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/pwm/lpc1850-pwm.txt
>>
>> diff --git a/Documentation/devicetree/bindings/pwm/lpc1850-pwm.txt b/Documentation/devicetree/bindings/pwm/lpc1850-pwm.txt
>> new file mode 100644
>> index 0000000..3055429
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/pwm/lpc1850-pwm.txt
>> @@ -0,0 +1,20 @@
>> +* NXP LPC18xx Pulse Width Modulator driver
>> +
>> +Required properties:
>> +  - compatible: Should be "nxp,lpc1850-pwm"
>> +  - reg: Should contain physical base address and length of pwm registers.
>> +  - clocks: Must contain an entry for each entry in clock-names.
>> +    See ../clock/clock-bindings.txt for details.
>> +  - clock-names: Must include the following entries.
>> +    - pwm: PWM operating clock.
>> +  - #pwm-cells: Should be 3. See pwm.txt in this directory for the description
>> +    of the cells format.
>> +
>> +Example:
>> +  pwm: pwm at 40000000 {
>> +    compatible = "nxp,lpc1850-pwm";
>
> I would prefer "nxp,lpc1850-sct" for a couple of reasons. SCT is the
> name of hardware block as described in the user manual and while PWM
> is the most obvious usage for this block on Linux, the hardware is not
> limited to just doing that. So as a bit of future proofing if someone
> wants to use this block for more than PWM I would prefer SCT.
>

Shouldn't we use something like "nxp,lpc1850-sct-pwm"?

Sounds like the word PWM should be in the compatible as it describes
not only the
device, but the device used in a certain way.

Otherwise, how would we use "nxp,lpc1850-sct" to distinguish a PWM from
e.g. a clocksource/clockevents (we can also use SCT for that)?

-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar