On 29 July 2015 at 15:47, Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx> wrote: > +devicetree guys > > On 28 July 2015 at 20:22, Joachim Eastwood <manabian@xxxxxxxxx> wrote: >> On 29 July 2015 at 00:45, Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx> wrote: >>> On 28 July 2015 at 19:37, Joachim Eastwood <manabian@xxxxxxxxx> wrote: >>>> On 27 July 2015 at 06:45, Ariel D'Alessandro <ariel@xxxxxxxxxxxxxxxxxxxx> wrote: >>>>> Add the devicetree binding document for NXP LPC18xx PWM/SCT. >>>>> >>>>> Signed-off-by: Ariel D'Alessandro <ariel@xxxxxxxxxxxxxxxxxxxx> >>>>> --- >>>>> .../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@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)? >> >> I not sure how to best handle dt bindings with such flexible hardware blocks. >> >> But are you suggestion to have multiple drivers for the same hw block? >> ie.: "nxp,lpc1850-sct-pwm" for PWM and for example >> "nxp,lpc1850-sct-clocksource" for clocksource and then use/enable one >> or the other. >> > > Yup, I'm suggesting just that. If the hardware is capable, I can't see > why we can't have different drivers for it. Well, I think it would be nice if we could have one driver per hw block. But then you need a way to select whether you want to use the counter in the SCT block for PWM or, for example, clocksource. Sort of mode selection I guess. But then again if someone has some very custom and application specific usage for the SCT block that maybe better served by a standalone driver anyway. So for now I am fine with "nxp,lpc1850-sct-pwm". I shouldn't be too hard to change the bindings if we see other users of this block, I believe. regards, Joachim Eastwood >> So I am not sure how to best handle this, but I think we should at >> least consider more than just PWM usage for this hw block. Note that >> not against calling it "lpc1850-sct-pwm", I like that better than just >> "lpc1850-pwm". >> > > > -- > Ezequiel García, VanguardiaSur > www.vanguardiasur.com.ar -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html