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

From: Dmitry Torokhov
Date: Wed Oct 31 2012 - 01:51:26 EST


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@xxxxxxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxxxxxx>
> > ---
> > 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
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