On 29 July 2015 at 00:45, Ezequiel Garcia <[email protected]> wrote: > On 28 July 2015 at 19:37, Joachim Eastwood <[email protected]> wrote: >> On 27 July 2015 at 06:45, Ariel D'Alessandro <[email protected]> >> wrote: >>> Add the devicetree binding document for NXP LPC18xx PWM/SCT. >>> >>> Signed-off-by: Ariel D'Alessandro <[email protected]> >>> --- >>> .../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. 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". regards, Joachim Eastwood -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
