Hi Rob,

On Wed, Mar 29, 2017 at 3:24 AM, Rob Herring [off-list ref] wrote:

On Wed, Mar 22, 2017 at 10:27:49AM -0400, Chris Brandt wrote:

quoted

--- /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-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

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
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html