From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Subject: Re: [PATCH 01/15] mfd: add new driver for Sharp LoCoMo
Date: Thu, 6 Nov 2014 00:02:49 +0400
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To: Linus Walleij <linus.walleij@linaro.org>
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2014-11-03 16:41 GMT+03:00 Linus Walleij <linus.walleij@linaro.org>:
> On Fri, Oct 31, 2014 at 10:54 AM, Dmitry Eremin-Solenikov
> <dbaryshkov@gmail.com> wrote:
>> 2014-10-31 10:42 GMT+03:00 Linus Walleij <linus.walleij@linaro.org>:
>
>>> It seems some DAC handling is part of the MFD driver, and we recently
>>> discussed that MFD should not be doing misc stuff but mainly act as
>>> arbiter and switching station.
>>>
>>> Can you please move the DAC parts of the driver to
>>> drivers/iio/dac?
>>>
>>> The IIO DAC subsystem will likely add other goodies to
>>> the driver for free and give a nice API to consumers.
>>
>> I wanted this part to be as simple as possible. I will look into IIO
>> DAC subsystem.
>> The DAC is as simple 2 channel 8-bit i2c device connected to a separate i2c bus
>> controlled through a register in LoCoMo device. One channel is used
>> for backlight,
>> other will be used for volume control. So (in theory) I can add the
>> following device
>> chain:  locomo -> i2c-locomo -> m62332 -> IIO DAC client.  However isn't that
>> quite an overkill for just backlight & volume control? Please advice me on this.
>
> The point is still the same: no unrelated code in drivers/mfd,
> then either use IIO DAC as a middle layer or sink the DAC handling
> into respective subdriver, i.e. push it into the backlight or
> volume directly then.

The problem is that the DAC is equally used by backlight and by sound
device (WIP).
What about true i2c device driver sitting in drivers/misc and exporting a regmap
of 2 8-bit registers?

-- 
With best wishes
Dmitry