2014-03-19 5:13 GMT+08:00 Thierry Reding <thierry.reding@xxxxxxxxx>: > On Wed, Mar 05, 2014 at 05:59:43PM +0800, Barry Song wrote: >> From: Barry Song <Baohua.Song@xxxxxxx> >> >> this patch adds dt-binding document for pwm-sirf. here the controller clock >> can't generate PWM signals, so we need seperate clock as signal source. > > Please capitalize properly. Also since the binding document should be OS > agnostic, it shouldn't be using the name of the driver in the Linux > kernel. > >> diff --git a/Documentation/devicetree/bindings/pwm/pwm-sirf.txt b/Documentation/devicetree/bindings/pwm/pwm-sirf.txt >> new file mode 100644 >> index 0000000..47851ea >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/pwm/pwm-sirf.txt >> @@ -0,0 +1,23 @@ >> +SiRF prima2 & atlas6 PWM drivers >> + >> +Required properties: >> +- compatible: "sirf,prima2-pwm" >> +- reg: physical base address and length of the controller's registers >> +- #pwm-cells: should be 2. The first cell specifies the per-chip index of the >> + PWM to use and the second cell is the period in nanoseconds. > > The canonical way to describe this property is: > > - #pwm-cells: Should be 2. See pwm.txt in this directory for a description of > the cells format. > >> +- clocks: from common clock binding: the 1st clock is for PWM controller the >> + other clocks are the sources to generate PWM signals >> +- clock-names : The first one is the name of the clock for PWM, others are names >> + of clock sources to generate PWM signal, e.g.sigsrc0 ~sigsrc4. For prima2 and >> + atlas6, sigsrc0 is OSC with 26MHz, sigsrc3 is RTC with 32KHz, others are PLLs. >> + Generally, PWM module uses the OSC as clock source to generate PWM signals. > > I think a more common way to write this is: > > - clocks: Must contain an entry for each entry in clock-names. > See ../clocks/clock-bindings.txt for details. > - clock-names: Must include the following entries: > - pwmc: PWM controller clock > - sigsrc0: source clock for ??? > - ... > - sigsrc4: source clock for ??? > > And perhaps given the requirements on prima2 and atlas6 (are those SoC > generations or boards?) specify what each clock should be set to. > > If prima2 and atlas6 are boards, then the binding shouldn't mention them > at all. prima2 and atlas6 are SoCs not boards. > > Thierry -barry -- 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
