[PATCHv3 1/3] dt-bindings: documentation: add clock bindings information for Stratix10

[Rob Herring]

On Fri, Feb 9, 2018 at 12:19 PM, Dinh Nguyen <dinguyen at kernel.org> wrote:
> Hi Rob,
>
>
> On 02/08/2018 08:43 PM, Rob Herring wrote:
>> On Mon, Feb 05, 2018 at 10:22:45AM -0600, Dinh Nguyen wrote:
>>> Document that Stratix10 clock bindings, and add the clock header file. The
>>> clock header is an enumeration of all the different clocks on the Stratix10
>>> platform.
>>>
>>> Signed-off-by: Dinh Nguyen <dinguyen at kernel.org>
>>> ---
>>> v3:
>>> - s/intc/intel for correct vendor prefix
>>> - fixup node name to "intel,stratix10-clkmgr"
>>> - document the required fixed-clock for oscillators
>>> v2:
>>> - use a single binding for the clock controller
>>> ---
>>>  .../devicetree/bindings/clock/intc_stratix10.txt   | 47 ++++++++++++
>>>  include/dt-bindings/clock/stratix10-clock.h        | 85 ++++++++++++++++++++++
>>>  2 files changed, 132 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/clock/intc_stratix10.txt
>>>  create mode 100644 include/dt-bindings/clock/stratix10-clock.h
>>>
>>> diff --git a/Documentation/devicetree/bindings/clock/intc_stratix10.txt b/Documentation/devicetree/bindings/clock/intc_stratix10.txt
>>> new file mode 100644
>>> index 0000000..8d218f4
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/clock/intc_stratix10.txt
>>> @@ -0,0 +1,47 @@
>>> +Device Tree Clock bindings for Intel's SoCFPGA Stratix10 platform
>>> +
>>> +This binding uses the common clock binding[1].
>>> +
>>> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
>>> +
>>> +Required properties:
>>> +- compatible : shall be
>>> +    "intel,stratix10-clkmgr"
>>> +
>>> +- reg : shall be the control register offset from CLOCK_MANAGER's base for the clock.
>>> +
>>> +- #clock-cells : from common clock binding, shall be set to 1.
>>> +
>>> +- clocks : Should contain fixed-clock sources, such as oscillators.
>>> +
>>> +Example:
>>> +    clkmgr: clock-controller at ffd10000 {
>>> +            compatible = "intel,stratix10-clkmgr";
>>> +            reg = <0xffd10000 0x1000>;
>>> +            #clock-cells = <1>;
>>> +
>>> +            clocks {
>>> +                    #address-cells = <1>;
>>> +                    #size-cells = <0>;
>>> +
>>> +                    cb_intosc_hs_div2_clk: cb_intosc_hs_div2_clk {
>>
>> Don't use '_' in node names.
>>
>
> Ok..
>
>>> +                            #clock-cells = <0>;
>>> +                            compatible = "fixed-clock";
>>
>> fixed clock with no frequency?
>
> The frequency gets populated in the board's dts file. This provides for
> the scenario where different boards might use different oscillator
> frequencies.

That is irrelevant for examples. The SoC vs. board file split is
outside the scope of the binding (i.e. not part of the ABI). Well, at
least until it is done with overlays.

Rob