Hi Geert,
On 14 June 2017 at 17:42, Geert Uytterhoeven <[email protected]> wrote:
> Hi Chunyan,
>
> On Wed, Jun 14, 2017 at 11:21 AM, Chunyan Zhang
> <[email protected]> wrote:
>> The value of property 'clock-cells' is not determined only by the number
>> of clock outputs in one clock node, it is determined by whether the clock
>> output in this node can be referenced directly without index. If the
>> output clock has to be referenced by a index, the clock-cell of this
>> clock node can't be defined 0.
>>
>> Signed-off-by: Chunyan Zhang <[email protected]>
>> ---
>> Documentation/devicetree/bindings/clock/clock-bindings.txt | 10 ++++++++++
>> 1 file changed, 10 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt
>> b/Documentation/devicetree/bindings/clock/clock-bindings.txt
>> index 2ec489e..e2b76b4 100644
>> --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt
>> +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt
>> @@ -18,6 +18,9 @@ Required properties:
>> with a single clock output and 1 for nodes with multiple
>> clock outputs.
>>
>> + There's one exception, please see the description for
>> + clock-indices below.
>> +
>> Optional properties:
>> clock-output-names: Recommended to be a list of strings of clock output
>> signal
>> names indexed by the first cell in the clock specifier.
>> @@ -48,6 +51,13 @@ clock-indices: If the identifying number for the
>> clocks in the node
>> is not linear from zero, then this allows the mapping of
>> identifiers into the clock-output-names array.
>>
>> + This property not only servers for clocks with multiple
>
> serves
Thanks, I will fix that.
>
>> + clock outputs, but also for clocks with a single clock
>> + output whose identifying number is not zero.
>
> Why would you want a single clock and a non-zero identifying number?
Because of the probably weird hardwire design :)
There indeed some clocks like that on the platform I'm working on.
>
>> + So long as clock-indices is set, clock-cells cannot be
>> + set zero.
>
> Gr{oetje,eeting}s,
>
> Geert
Thanks for your review,
Chunyan
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 --
> [email protected]
>
> 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
