Re: [PATCH] ti_tscadc: Match mfd sub devices to regmap interface

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Tue, Oct 30, 2012 at 09:41:00PM -0700, Russ Dill wrote:
> On Wed, Oct 31, 2012 at 8:55 AM, Pantelis Antoniou
> <panto@antoniou-consulting.com> wrote:
> > The MFD parent device now uses a regmap, instead of direct
> > memory access. Use the same method in the sub devices to avoid
> > nasty surprises.
> >
> > Also rework the channel initialization of tiadc a bit.
> >
> > Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>
> > ---
> >  drivers/iio/adc/ti_am335x_adc.c           | 27 +++++++++++++++++++--------
> >  drivers/input/touchscreen/ti_am335x_tsc.c | 16 +++++++++++++---
> >  drivers/mfd/ti_am335x_tscadc.c            |  7 +++++--
> >  3 files changed, 37 insertions(+), 13 deletions(-)
> >
> > diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
> > index d48fd79..5f325c1 100644
> > --- a/drivers/iio/adc/ti_am335x_adc.c
> > +++ b/drivers/iio/adc/ti_am335x_adc.c
> > @@ -23,7 +23,9 @@
> >  #include <linux/iio/iio.h>
> >  #include <linux/iio/machine.h>
> >  #include <linux/iio/driver.h>
> > +#include <linux/regmap.h>
> >
> > +#include <linux/io.h>
> >  #include <linux/mfd/ti_am335x_tscadc.h>
> >  #include <linux/platform_data/ti_am335x_adc.h>
> >
> > @@ -36,13 +38,17 @@ struct tiadc_device {
> >
> >  static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> >  {
> > -       return readl(adc->mfd_tscadc->tscadc_base + reg);
> > +       unsigned int val;
> > +
> > +       val = (unsigned int)-1;
> > +       regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
> > +       return val;
> >  }
> 
> Would it be cleaner to instead do:
> 
> static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
> {
>        unsigned int val;
> 
>        return regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val) ? : val;
> }
> 
> or
>        int ret;
> 
>        ret = regmap_read(adc->mfd_tscadc->regmap_tscadc, reg, &val);
>        return ret < 0 ret ? : val;

Also the function should not be returning unsigned int if it returns
errors.

Thanks.

-- 
Dmitry