Re: [PATCH v3 2/5] mfd: sec: Add support for S2MPS15 PMIC

[Krzysztof Kozlowski <k.kozlowski@samsung.com>]

W dniu 28.10.2015 o 20:21, Alim Akhtar pisze:
> Hello,
> 
> On 10/28/2015 02:16 PM, Lee Jones wrote:
>> On Wed, 28 Oct 2015, Krzysztof Kozlowski wrote:
>>
>>> On 26.10.2015 23:34, Lee Jones wrote:
>>>> On Mon, 26 Oct 2015, Alim Akhtar wrote:
>>>>
>>>>> From: Thomas Abraham <thomas.ab@samsung.com>
>>>>>
>>>>> Add support for S2MPS15 PMIC which is similar to S2MPS11 PMIC. The
>>>>> S2MPS15
>>>>> PMIC supports 27 LDO regulators, 10 buck regulators, RTC, three
>>>>> 32.768KHz
>>>>> clock outputs and battery charger. This patch adds initial support for
>>>>> LDO and buck regulators of S2MPS15 device.
>>>>>
>>>>> Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
>>>>> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
>>>>> [Alim: Added s2mps15_devs like rtc and clk and related changes]
>>>>> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>>>> ---
>>>>>   drivers/mfd/sec-core.c              |   31 +++++++
>>>>>   drivers/mfd/sec-irq.c               |    8 ++
>>>>>   include/linux/mfd/samsung/core.h    |    1 +
>>>>>   include/linux/mfd/samsung/s2mps15.h |  158
>>>>> +++++++++++++++++++++++++++++++++++
>>>>>   4 files changed, 198 insertions(+)
>>>>>   create mode 100644 include/linux/mfd/samsung/s2mps15.h
>>>>
>>>> I replied to the previous set and won't be reviewing this one until
>>>> all of the open points are solved.
>>>
>>> The naming and compatibles used by the driver are confusing but how it
>>> was at beginning. Beside the confusion, the names are correct:
>>>
>>> 1. Main mfd driver:
>>>   - compatible: samsung,s2mps1*-pmic
>>>   - driver name: sec_pmic
>>>
>>> 2. Regulator driver:
>>>   - no compatible (because it always searches for "regulators"
>>> subnode of
>>> its parent... that is the convention/legacy behaviour)
>>>   - driver name: s2mps1*-pmic
>>>
>>> I hope that explains your concerns.
>>
>> It explains *why*, but doesn't ease my concerns in any way.
>>
>> Unfortunately I've only just realised the disparity we have between
>> MFD and the Regulator subsystem, which is annoying because it's now
>> almost impossible to rectify.
>>
>> We should have taken one of two views.  Either a) The MFD is the PMIC
>> device which encompasses regulator control.  In which case the MFD
>> and it's corresponding compatible string would be named *-pmic and the
>> regulator driver would be called *-regulator. Or b) The MFD could be
>> considered a normal MFD and be named after the model number, then the
>> regulator 'could' be named *-pmic.
>>
>> However, with reference to b), how much other Power Management does
>> the regulator driver do besides control regulators?  I suspect not
>> much.  Therefore my preference would be for a).  My second choice
>> would be a mixuture of the two where nothing gets named *-pmic.  The
>> last option on my list would be the current situation where we seem to
>> be calling both the MFD (PMIC) itself and the Regulator driver
>> *-pmic, which is not good.
>>
> Well, I would have also preferred option a), but keeping existing DT
> bindings, looks like we need to go with the current situation.
> Krzysztof any thought on this?
> 

Looks good to me. Please, go ahead.

Best regards,
Krzysztof