Re: [PATCH v5 2/2] iio: proximity: Add driver support for vcnl3020 proximity sensor

From: Ivan Mikhaylov
Date: Mon Mar 30 2020 - 16:41:13 EST


On Mon, 2020-03-30 at 22:07 +0300, Andy Shevchenko wrote:
> On Mon, Mar 30, 2020 at 6:27 PM Ivan Mikhaylov <i.mikhaylov@xxxxxxxxx> wrote:
> > Proximity sensor driver based on light/vcnl4000.c code.
> > For now supports only the single on-demand measurement.
> >
> > The VCNL3020 is a fully integrated proximity sensor. Fully
> > integrated means that the infrared emitter is included in the
> > package. It has 16-bit resolution. It includes a signal
> > processing IC and features standard I2C communication
> > interface. It features an interrupt function.
>
> Still my tag applies, but
> I have few more comments below.
>
> ...
>
> > +#define VCNL_DRV_NAME "vcnl3020"
> > +#define VCNL_REGMAP_NAME "vcnl3020_regmap"
>
> I'm wondering why you need the second one.

For regmap initialize as name in
static const struct regmap_config vcnl3020_regmap_config = {
.name = VCNL_REGMAP_NAME,

I can get rid of it from struct with name definition.

> > + rc = device_property_read_u32(data->dev, "vishay,led-current-
> > milliamp",
> > + &led_current);
> > + if (rc == 0) {
> > + rc = regmap_write(data->regmap, VCNL_LED_CURRENT,
> > led_current);
> > + if (rc)
> > + dev_err(data->dev,
> > + "Error (%d) setting LED current", rc);
> > + }
> > +
> > + return rc;
>
> Why not to use standard pattern, i.e.
>
> if (rc)
> return rc;
> ...
> rc = regmap_write(...);
>
> ?

Optional parameter. There exists a lot of ways to do it:

rc = device_property_read_u32(dev, "milliamp", &led_current);
rc = regmap_write(regmap, VCNL_LED_CURRENT, (!rc) : led_current ? 0);
or

rc = regmap_write(regmap, VCNL_LED_CURRENT, (!rc) : led_current ?
VCNL_LED_CURRENT_DEFAULT);
or even maybe make a function like get_led_current:

rc = regmap_write(regmap, VCNL_LED_CURRENT, get_led_curent(dev));
where
static u32 get_led_current(dev) {
u32 led_current;
rc = device_property_read_u32(dev, "milliamp", &led_current);
return (!rc) : led_current ? VCNL_LED_CURRENT_DEFAULT;
}
Which one would be more preferable?

> ...
>
> > + if (rc) {
> > + dev_err(data->dev,
> > + "vcnl3020_measure() failed with error (%d)", rc);
>
> Perhaps you keep same pattern for error messages as in previous function(s).

Sure.

>
> > + goto err_unlock;
> > + }
> > + rc = regmap_bulk_read(data->regmap, VCNL_PS_RESULT_HI, &res, 2);
>
> sizeof(res)

Oops.