Re: [PATCH v2 1/5] iio: light: vcnl4000 use word writes instead of byte writes

[Angus Ainslie]

Hi Tomas,

On 2019-03-20 07:53, Tomas Novotny wrote:
> Hi Angus,
>
> On Sun, 17 Mar 2019 08:47:58 -0700
> "Angus Ainslie (Purism)" <angus@xxxxxxxx> wrote:
>
> > The VCNL4200 datasheet says that word read and writes should be used
> > to access the registers.
> >
> > Signed-off-by: Angus Ainslie (Purism) <angus@xxxxxxxx>
> > ---
> >  drivers/iio/light/vcnl4000.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/iio/light/vcnl4000.c 
> > b/drivers/iio/light/vcnl4000.c
> > index 04fd0d4b6f19..5295330b65e2 100644
> > --- a/drivers/iio/light/vcnl4000.c
> > +++ b/drivers/iio/light/vcnl4000.c
> > @@ -140,10 +140,10 @@ static int vcnl4200_init(struct vcnl4000_data 
> > *data)
> >  	data->rev = (ret >> 8) & 0xf;
> >
> >  	/* Set defaults and enable both channels */
> > -	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_AL_CONF, 
> > 0x00);
> > +	ret = i2c_smbus_write_word_data(data->client, VCNL4200_AL_CONF, 
> > 0x00);
>
> minor note: the 0x00 looks like a byte. 0 or 0x0000 would be slightly 
> better?
> The same below.
>
> >  	if (ret < 0)
> >  		return ret;
> > -	ret = i2c_smbus_write_byte_data(data->client, VCNL4200_PS_CONF1, 
> > 0x00);
> > +	ret = i2c_smbus_write_word_data(data->client, VCNL4200_PS_CONF1, 
> > 0x00);
>
> The VCNL4200_PS_CONF1 definition is a bit misleading with word write. 
> Because
> PS_CONF1 is only a low byte of command code 0x03. The high byte of 0x03 
> is
> PS_CONF2. I would rename it.

As far as a base address for the register that is correct based on the 
names in the datasheet. I suppose I could add something like:

#define VCNL4200_PS_CONF  VCNL4200_PS_CONF1

and change the reference here if you think that would be more clear.

> >  	if (ret < 0)
> >  		return ret;
>
> Anyway, the main point is that I've tested this patch on VCNL4200 and 
> it
> works, so:
> Tested-by: Tomas Novotny <tomas@xxxxxxxxxx>
>
> T.

Thanks for testing it
Angus