Hi Chris,
On Fri, Mar 17, 2017 at 2:20 PM, Chris Brandt <Chris.Brandt@xxxxxxxxxxx> wrote:
> On Friday, March 17, 2017, Geert Uytterhoeven wrote:
>> > --- a/arch/arm/boot/dts/r7s72100.dtsi
>> > +++ b/arch/arm/boot/dts/r7s72100.dtsi
>> > @@ -117,6 +117,15 @@
>> > clock-output-names = "ostm0", "ostm1";
>> > };
>> >
>> > + mstp6_clks: mstp6_clks@fcfe042c {
>> > + #clock-cells = <1>;
>> > + compatible = "renesas,r7s72100-mstp-clocks",
>> "renesas,cpg-mstp-clocks";
>> > + reg = <0xfcfe042c 4>;
>> > + clocks = <&p0_clk>;
>> > + clock-indices = <R7S72100_CLK_RTC>;
>> > + clock-output-names = "rtc0";
>>
>> "rtc"? There's only one.
>
> The rtc-sh.c code wants to have a number at the end. So if I just put "rtc" as the clock name, it does not find it. Again, I didn't want to break any SH builds, so I just changed the DT to match the driver.
Hmm...
> [ from the rtc-sh.c code ]
>
> clk_id = pdev->id;
> /* With a single device, the clock id is still "rtc0" */
> if (clk_id < 0)
> clk_id = 0;
>
> snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
>
> rtc->clk = devm_clk_get(&pdev->dev, clk_name);
So in the absence of an "rtc0" clock in the device node (you don't have
"clock-names" properties in the rtc devvice node yet), it will fall back to
clk_get_sys(), and will find the global "rtc0" clock. Unless you call it
"rtc"...
Most drivers using a single clock just pass NULL instead of a name, so it
will match the first clock found.
I think the simplest solution is to check if your device is instantiated
from DT (pdev->dev.of_node != NULL), and pass NULL (or "fck", when you add
multiple clocks to the DT bindings) to devm_clk_get() if that's the case.
> if (IS_ERR(rtc->clk)) {
> /*
> * No error handling for rtc->clk intentionally, not all
> * platforms will have a unique clock for the RTC, and
> * the clk API can handle the struct clk pointer being
> * NULL.
> */
> rtc->clk = NULL;
> }
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
