Hi Rob,
On Wed, Mar 29, 2017 at 3:24 AM, Rob Herring <robh@xxxxxxxxxx> wrote:
> On Wed, Mar 22, 2017 at 10:27:49AM -0400, Chris Brandt wrote:
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/rtc/rtc-sh.txt
>> @@ -0,0 +1,29 @@
>> +* Real Time Clock for Renesas SH and ARM SoCs
>> +
>> +Required properties:
>> +- compatible: Should be "renesas,r7s72100-rtc" and "renesas,sh-rtc" as a
>> + fallback.
>> +- reg: physical base address and length of memory mapped region.
>> +- interrupts: 3 interrupts for alarm, period, and carry.
>> +- interrupt-names: The interrupts should be labeled as "alarm", "period", and
>> + "carry".
>> +- clocks: The functional clock source for the RTC controller must be listed
>> + first (if exists). Additionally, potential clock counting sources are to be
>> + listed.
>> +- clock-names: The functional clock must be labeled as "fck". Other clocks
>> + may be named in accordance to the SoC hardware manuals.
>> +
>> +
>> +Example:
>> +rtc: rtc@fcff1000 {
>> + compatible = "renesas,r7s72100-rtc", "renesas,sh-rtc";
>> + reg = <0xfcff1000 0x2e>;
>> + interrupts = <GIC_SPI 276 IRQ_TYPE_EDGE_RISING
>> + GIC_SPI 277 IRQ_TYPE_EDGE_RISING
>> + GIC_SPI 278 IRQ_TYPE_EDGE_RISING>;
>> + interrupt-names = "alarm", "period", "carry";
>> + clocks = <&mstp6_clks R7S72100_CLK_RTC>, <&rtc_x1_clk>,
>> + <&rtc_x3_clk>, <&extal_clk>;
>> + clock-names = "fck", "rtc_x1", "rtc_x3", "extal";
>> + power-domains = <&cpg_clocks>;
>
> Not documented.
"power-domains" is a platform property.
All hardware components need power.
All synchronous hardware components need a clock.
Most hardware components have a reset signal.
Whether these are exposed and can be controlled depends on the platform/SoC.
So documenting them in each and every device binding looks overkill to me.
I think this is something to be addressed by devicetree-specification (which
doesn't handle clocks, power-domains, resets yet).
If you prefer, the property can be removed from the example, though.
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
