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From: Mark Brown on 1 Apr 2010 14:40
On Thu, Apr 01, 2010 at 01:23:32PM +0200, Rodolfo Giometti wrote:

This looks good, a few nitpicky things below.

> +config REGULATOR_DS1803
> + tristate "Dallas Maxim DS1803 addressable dual digital potentiometer"
> + depends on I2C
> + help
> + Say Y here to support the dual digital potentiometer on
> + Dallas Maxim DS1803
> +

Oh, wow. A pot as a voltage regulator... :)

> +struct ds1803_data {
> + struct i2c_client *client;
> + struct regulator_dev *rdev;
> +
> + unsigned int min_uV; /* voltage for selector value 0 */
> + unsigned int max_uV; /* voltage for selector value 255 */
> + unsigned int init_uV; /* initial voltage */

Given that you don't support get_voltage() or otherwise reference
init_uV it seems as well to just drop that for now.

> +static u8 ds1803_write_pot_lut[] = { 0xa9, 0xaa, /* both not supported */ };

Both what? Since you don't seem to reference this I guess it could just
be dropped...

> +static int ds1803_list_voltage(struct regulator_dev *rdev, unsigned index)
> +{
> + struct ds1803_data *ds1803 = rdev_get_drvdata(rdev);
> +
> + return (ds1803->max_uV - ds1803->min_uV) * index / 255
> + + ds1803->min_uV;
> +}

I think I'd like more brackets in this calculation for clarity that the
operator precedence is OK.

> + /* Set chip's name according to user supplied type */
> + ds1803_reg[i].name = ds1803_names[pdata->type];

Perhaps just let the user write in something they feel like, or use a
constant string for the chip? The type doesn't seem to be used
otherwise so I can see the data ending up wrong and misleading folks.

> +enum ds1803_type {
> + DS1803_100K,
> + DS1803_50K,
> + DS1803_10K,
> +};

If you are going to keep these assign a value to the first item so you
don't end up with 0 as a valid type, or make the 0 type be "unspecified"
or something. That way platform data that's left initialised to zero
can be distinguished from something that someone deliberately set.
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