On 03/20/2013 04:12 AM, Joseph Lo wrote:
> On Wed, 2013-03-20 at 00:42 +0800, Stephen Warren wrote:
>> On 03/18/2013 02:09 AM, Joseph Lo wrote:
>>> The clock source of PMC is PCLK. Adding it into DTS for Tegra20 and Tegra30.
>>
>>> diff --git a/arch/arm/boot/dts/tegra20.dtsi b/arch/arm/boot/dts/tegra20.dtsi
>>
>>> pmc {
>>> compatible = "nvidia,tegra20-pmc";
>>> reg = <0x7000e400 0x400>;
>>> + clocks = <&tegra_car 110>;
>>> };
>>
>> The DT binding documentation needs to list the set of clocks that must
>> be present.
>>
>> Doesn't the PMC also receive a "clk32k_in" from the PMIC, or is that
>> routed into the CAR, and then into the PMC? Either way, the PMC module
>> receives that clock somehow. Since there are multiple clocks, that also
>> means that a clock-names property is required.
>
> Do you mean the DTS below and add it into binding document?
>
> / SoC dts including file
> pmc {
> compatible = "nvidia,tegra20-pmc";
> reg = <0x7000e400 0x400>;
> clocks = <&tegra_car 110>, <&clk32k_in>;
> clock-names= "pclk", "clk32k_in";
> };
Yes, that's what should technically be present.
> / Tegra board dts file
>
> pmic {
> ...
> clocks {
> compatible = "simple-bus";
> #address-cells = <1>;
> #size-cells = <0>;
>
> clk32k_in: clock@0 {
> compatible = "fixed-clock";
> reg=<0>;
> #clock-cells = <0>;
> clock-frequency = <32768>;
> };
> };
> };
That won't work; the PMIC drivers don't enumerate sub-nodes as busss, so
that clocks node won't ever be processed. Also, the PMIC drivers aren't
clock providers in most cases. It's not quite a correct representation
of the HW, but I would suggest simply creating a top-level "clock" node
for that fixed clock. If we ever have more top-level clocks, we can move
them into a top-level "clocks" node at that time.
Note: If there aren't already any other top-level clock nodes (which I
think is the case), the node can be named just "clock" rather than
"clock@0", since there are no naming conflicts.
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