Re: [PATCH v10 6/8] iio: adc: Support ROHM BD79124 ADC

[Matti Vaittinen]

On 30/03/2025 19:35, Jonathan Cameron wrote:
> On Mon, 24 Mar 2025 10:23:52 +0200
> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
>
> > On Mon, Mar 24, 2025 at 09:13:42AM +0200, Matti Vaittinen wrote:
> > > The ROHM BD79124 is a 12-bit, 8-channel, SAR ADC. The ADC supports
> > > an automatic measurement mode, with an alarm interrupt for out-of-window
> > > measurements. The window is configurable for each channel.
> > >
> > > The I2C protocol for manual start of the measurement and data reading is
> > > somewhat peculiar. It requires the master to do clock stretching after
> > > sending the I2C slave-address until the slave has captured the data.
> > > Needless to say this is not well suopported by the I2C controllers.
> > >
> > > Thus do not support the BD79124's manual measurement mode but implement
> > > the measurements using automatic measurement mode, relying on the
> > > BD79124's ability of storing latest measurements into register.
> > >
> > > Support also configuring the threshold events for detecting the
> > > out-of-window events.
> > >
> > > The BD79124 keeps asserting IRQ for as long as the measured voltage is
> > > out of the configured window. Thus, prevent the user-space from choking
> > > on the events and mask the received event for a fixed duration (1 second)
> > > when an event is handled.
> > >
> > > The ADC input pins can be also configured as general purpose outputs.
> > > Make those pins which don't have corresponding ADC channel node in the
> > > device-tree controllable as GPO.
> >
> > Thank you for the nicely written driver!
> > However, I have one big issue with it (see below).
> >
> > ...
> >
> > > +static void bd79124gpo_set(struct gpio_chip *gc, unsigned int offset, int value)
> > > +static void bd79124gpo_set_multiple(struct gpio_chip *gc, unsigned long *mask,
> > > +				    unsigned long *bits)
> >
> > These will be _rv variants anyway as there is no chance this series goes before that.
>
> I don't mind seeing this as a follow up series, but I would like that
> to hit this cycle if possible.

Should be possible :) I think the use of _rv will nicely tidy-up the 
set_multiple. I'll cook a patch when rc1 is out - or when IIO has the 
_rv variants in a branch where I can base the changes.

Yours,
	-- Matti