Re: [PATCH] iio: adc: max9611: Make enum relations more future proof

[Jonathan Cameron <jic23@kernel.org>]

On Sat, 16 Nov 2019 17:54:44 +0100
Jacopo Mondi <jacopo@jmondi.org> wrote:

> Hello,
> 
> On Sat, Nov 16, 2019 at 04:25:22PM +0000, Jonathan Cameron wrote:
> > On Thu, 14 Nov 2019 08:28:03 +0100
> > Niklas Söderlund <niklas.soderlund@ragnatech.se> wrote:
> >  
> > > Hi Geert,
> > >
> > > Looks good.
> > >
> > > On 2019-11-13 11:09:38 +0100, Geert Uytterhoeven wrote:  
> > > > The relations between enum values and array indices values are currently
> > > > not enforced by the code, which makes them fragile w.r.t. future
> > > > changes.
> > > >
> > > > Fix this by:
> > > >   1. Using designated array initializers, to make sure array indices and
> > > >      enums values match,
> > > >   2. Linking max9611_csa_gain enum values to the corresponding
> > > >      max9611_conf_ids enum values, as the latter is cast to the former
> > > >      in max9611_read_csa_voltage().
> > > >
> > > > No change in generated code.
> > > >
> > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>  
> > >
> > > Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>  
> >
> > Looks good to me, but I'd like to leave a little longer for any
> > feedback from Jacopo as author of the driver.  
> 
> yeah, sorry I've been sloppy.. I meant to give the patches a run, but
> it seems there are only syntactic changes here, which indeed make the
> code more robust.
> 
> Even if not tested, please add
> Acked-by: Jacopo Mondi <jacopo@jmondi.org>

Thanks!

Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to poke at it.

Thanks,

J
> 
> Thanks
>   j
> 
> >
> > Thanks,
> >
> > Jonathan  
> > >  
> > > > ---
> > > >  drivers/iio/adc/max9611.c | 36 +++++++++++-------------------------
> > > >  1 file changed, 11 insertions(+), 25 deletions(-)
> > > >
> > > > diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
> > > > index b0755f25356d700d..cb306ff1a5d6a0b2 100644
> > > > --- a/drivers/iio/adc/max9611.c
> > > > +++ b/drivers/iio/adc/max9611.c
> > > > @@ -114,22 +114,17 @@ enum max9611_conf_ids {
> > > >   *		      where data shall be read from
> > > >   */
> > > >  static const unsigned int max9611_mux_conf[][2] = {
> > > > -	/* CONF_SENSE_1x */
> > > > -	{ MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA },
> > > > -	/* CONF_SENSE_4x */
> > > > -	{ MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA },
> > > > -	/* CONF_SENSE_8x */
> > > > -	{ MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA },
> > > > -	/* CONF_IN_VOLT */
> > > > -	{ MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA },
> > > > -	/* CONF_TEMP */
> > > > -	{ MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA },
> > > > +	[CONF_SENSE_1x]	= { MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA },
> > > > +	[CONF_SENSE_4x]	= { MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA },
> > > > +	[CONF_SENSE_8x]	= { MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA },
> > > > +	[CONF_IN_VOLT]	= { MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA },
> > > > +	[CONF_TEMP]	= { MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA },
> > > >  };
> > > >
> > > >  enum max9611_csa_gain {
> > > > -	CSA_GAIN_1x,
> > > > -	CSA_GAIN_4x,
> > > > -	CSA_GAIN_8x,
> > > > +	CSA_GAIN_1x = CONF_SENSE_1x,
> > > > +	CSA_GAIN_4x = CONF_SENSE_4x,
> > > > +	CSA_GAIN_8x = CONF_SENSE_8x,
> > > >  };
> > > >
> > > >  enum max9611_csa_gain_params {
> > > > @@ -147,18 +142,9 @@ enum max9611_csa_gain_params {
> > > >   * value; use this structure to retrieve the correct LSB and offset values.
> > > >   */
> > > >  static const unsigned int max9611_gain_conf[][2] = {
> > > > -	{ /* [0] CSA_GAIN_1x */
> > > > -		MAX9611_CSA_1X_LSB_nV,
> > > > -		MAX9611_CSA_1X_OFFS_RAW,
> > > > -	},
> > > > -	{ /* [1] CSA_GAIN_4x */
> > > > -		MAX9611_CSA_4X_LSB_nV,
> > > > -		MAX9611_CSA_4X_OFFS_RAW,
> > > > -	},
> > > > -	{ /* [2] CSA_GAIN_8x */
> > > > -		MAX9611_CSA_8X_LSB_nV,
> > > > -		MAX9611_CSA_8X_OFFS_RAW,
> > > > -	},
> > > > +	[CSA_GAIN_1x] = { MAX9611_CSA_1X_LSB_nV, MAX9611_CSA_1X_OFFS_RAW, },
> > > > +	[CSA_GAIN_4x] = { MAX9611_CSA_4X_LSB_nV, MAX9611_CSA_4X_OFFS_RAW, },
> > > > +	[CSA_GAIN_8x] = { MAX9611_CSA_8X_LSB_nV, MAX9611_CSA_8X_OFFS_RAW, },
> > > >  };
> > > >
> > > >  enum max9611_chan_addrs {
> > > > --
> > > > 2.17.1
> > > >  
> > >  
> >