[PATCH v3 2/2] i2c: mv64xxx: Fix clock resource by adding an optional bus clock
Gregory CLEMENT
gregory.clement at free-electrons.com
Fri Jan 12 03:15:26 PST 2018
Hi Maxime,
On ven., janv. 12 2018, Maxime Ripard <maxime.ripard at free-electrons.com> wrote:
> Hi,
>
> On Fri, Jan 12, 2018 at 11:39:56AM +0100, Gregory CLEMENT wrote:
>> On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
>> is optional because not all the SoCs need them but at least for Armada
>> 7K/8K it is actually mandatory.
>>
>> The binding documentation is updating accordingly.
>>
>> Signed-off-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
>> ---
>> .../devicetree/bindings/i2c/i2c-mv64xxx.txt | 20 ++++++++++++++++++++
>> drivers/i2c/busses/i2c-mv64xxx.c | 12 +++++++++++-
>> 2 files changed, 31 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> index 5c30026921ae..3d76bb19492f 100644
>> --- a/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> +++ b/Documentation/devicetree/bindings/i2c/i2c-mv64xxx.txt
>> @@ -25,6 +25,15 @@ default frequency is 100kHz
>> whenever you're using the "allwinner,sun6i-a31-i2c"
>> compatible.
>>
>> + - clocks: : pointers to the reference clocks for this device, the
>> + first one is the one used for the clock on the i2c bus,
>> + the second one is the clock used for the functional part
>> + of the controller
>
> This documentation is confusing, as usually the functional clock is
> the clock driving the bus, as opposed to the interface clock clocking
> the bus interface.
I don't find it less confusing, for my point of view the interface of a
bus is the lines interfacing the bus with the devices on this bus. But I
don't mind modifying it, as I clearly state that the first clock is the
one used to generate the clock of the i2c bus, so we can change the
name.
>
>> + - clock-names : names of used clocks, mandatory if the second clock is
>> + used, the name must be "core", and "axi" (the latter is
>> + only for Armada 7K/8K).
>> +
>
> Are you sure the i2c controller is on the AXI bus? It seems more
> likely to be on an APB bus.
No I am not sure :)
Actually I don't have this information, so lets call it "reg" for
register clock.
Gregory
>
> Maxime
>
> --
> Maxime Ripard, Free Electrons
> Embedded Linux and Kernel engineering
> http://free-electrons.com
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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