Re: [PATCH v1 08/13] iio: chemical: bme680: add power management

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 11 Oct 2024 21:02:32 +0200
Vasileios Aoiridis <vassilisamir@gmail.com> wrote:

> On Fri, Oct 11, 2024 at 01:10:20PM +0300, Andy Shevchenko wrote:
> > On Thu, Oct 10, 2024 at 11:00:25PM +0200, vamoirid wrote:  
> > > From: Vasileios Amoiridis <vassilisamir@gmail.com>
> > > 
> > > Add runtime power management to the device. To facilitate this, add also
> > > a struct dev * inside the bme680_data structure to have the device
> > > accesible from the data structure.  
> > 
> > ...
> >   
> > > --- a/drivers/iio/chemical/bme680.h
> > > +++ b/drivers/iio/chemical/bme680.h
> > > @@ -75,6 +75,7 @@
> > >  #define BME680_CALIB_RANGE_3_LEN               5
> > >  
> > >  extern const struct regmap_config bme680_regmap_config;
> > > +extern const struct dev_pm_ops bmp280_dev_pm_ops;  
> > 
> > Is pm.h being included already in this header? Otherwise you need to add it.
> >  
> 
> No it is not, and indeed I need to add it. Probably because it was
> included by some other file I didn't get an error from gcc?
> 
> > ...
> >   
> > >  	struct regmap *regmap;
> > >  	struct bme680_calib bme680;
> > >  	struct mutex lock; /* Protect multiple serial R/W ops to device. */
> > > +	struct device *dev;  
> > 
> > Is it the same that you may get wia regmap_get_device()?
> >   
> 
> Yes it is the same. Maybe I can try and see if I can use the following
> 
> 	regmap_get_device(data->regmap)
> 
> in the places where the pm functions are used in order to not declare a
> new value inside the struct bme680_data. But in general, is this approach
> prefered?

slightly by me.  I tend not to poke on that if people have chosen a local
variable, but it is a little neater.

This patch might get caught up in an effort to simplify the
autosuspend handling but if it is we'll deal with that whilst merging.
There 'should' be a clean path to transition from this style to the proposed
new one where a simple pm_runtime_put() without the mark_last_busy stuff
is enough for autosuspend cases.

Jonathan