[PATCH 3/6] mfd: devicetree: bindings: 88pm800: Add DT property for 32KHz output enable
vaibhav.hiremath at linaro.org
Mon Jul 13 00:24:46 PDT 2015
On Saturday 11 July 2015 12:41 PM, Krzysztof Kozlowski wrote:
> W dniu 09.07.2015 o 20:47, Vaibhav Hiremath pisze:
>> 88PM800 family of device supports output of 32KHz clock (low jitter)
>> on CLK32K2/3 pin which can be supplied to other peripherals on the board.
>> This patch adds the devicetree binding to enable this feature.
>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath at linaro.org>
>> Documentation/devicetree/bindings/mfd/88pm800.txt | 6 ++++++
>> 1 file changed, 6 insertions(+)
>> diff --git a/Documentation/devicetree/bindings/mfd/88pm800.txt b/Documentation/devicetree/bindings/mfd/88pm800.txt
>> index dec842f..ae1311c 100644
>> --- a/Documentation/devicetree/bindings/mfd/88pm800.txt
>> +++ b/Documentation/devicetree/bindings/mfd/88pm800.txt
>> @@ -9,6 +9,12 @@ Required parent device properties:
>> - #interrupt-cells : should be 1.
>> The cell is the 88pm80x local IRQ number
>> +Optional properties :
>> + - marvell,88pm800-32khz-xolj-out-en : If set, driver will enable low jitter
>> + version of 32Khz clock output on
> I am not sure if I understand it correctly. The hardware always has such
> clocks and you only want to enable/disable it in DT? Any reasons why
> these should not be enabled always?
Small amount of Power savings...
Although currently I do not have power numbers to justify this.
As per spec, (it only talks about power consumption in power down state)
Power-down State => VSYS > 2.8 => 4.5 μA
CLK32K2 = 0 => 18 μW
> Enabling it in DT does not look like a job for DT. Maybe you there
> should be just a clock driver (clock provider)?
It's init time (and one time) settings, wouldn't clock-provider
be overkill for this?
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