Re: [PATCH v2] iio: tsl2772: Use device-managed API

[Chuhong Yuan <hslester96@gmail.com>]

Brian Masney <masneyb@onstation.org> 于2019年7月29日周一 下午6:59写道：
>
> Hi Chuhong,
>
> On Mon, Jul 29, 2019 at 06:03:39PM +0800, Chuhong Yuan wrote:
> > Use devm_iio_device_register to simplify
> > the code.
> >
> > Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
>
> Thank you for the patch. The patch description doesn't match what all is
> done below. This should also be broken up into multiple patches since a
> patch should only do one thing. The regulator changes should be in their
> own patch, and some of the devm changes may require multiple patches.
> When writing your changelog, if your patch description has the word
> 'and', then that may be a hint that you need to break up your patch a
> little bit. That's not always the case, but something to keep in mind.
>

Thanks for your advice.
I will split it into two patches in next version.
One is to use devm to simpliy the code.
The other is to use regulator_bulk_() to shrink driver size.

> A few minor comments below.
>
> > ---
> > Changes in v2:
> >   - Use regulator_bulk_() to shrink driver
> >     size.
> >   - Utilize more devm functions to simplify
> >     the code.
> >   - Remove several redundant functions.
> >
> >  drivers/iio/light/tsl2772.c | 116 +++++++++++-------------------------
> >  1 file changed, 34 insertions(+), 82 deletions(-)
> >
> > diff --git a/drivers/iio/light/tsl2772.c b/drivers/iio/light/tsl2772.c
> > index 83cece921843..946537c8586f 100644
> > --- a/drivers/iio/light/tsl2772.c
> > +++ b/drivers/iio/light/tsl2772.c
> > @@ -131,7 +131,10 @@ enum {
> >  enum {
> >       TSL2772_CHIP_UNKNOWN = 0,
> >       TSL2772_CHIP_WORKING = 1,
> > -     TSL2772_CHIP_SUSPENDED = 2
> > +     TSL2772_CHIP_SUSPENDED = 2,
> > +     TSL2772_SUPPLY_VDD = 0,
> > +     TSL2772_SUPPLY_VDDIO = 1,
> > +     TSL2772_NUM_SUPPLIES = 2
> >  };
>
> This is a really minor nitpick but can these either use a #define or be
> placed in its own enum block?
>

I refer to drivers/iio/adc/ad7766.c when I use regulator_bulk_().
This file puts them in the enum block.
There are also files using #define, like drivers/iio/dac/ad5064.c and
ad5449.c.
I think both of them are okay.

> >
> >  /* Per-device data */
> > @@ -161,8 +164,7 @@ struct tsl2772_chip {
> >       struct mutex prox_mutex;
> >       struct mutex als_mutex;
> >       struct i2c_client *client;
> > -     struct regulator *vdd_supply;
> > -     struct regulator *vddio_supply;
> > +     struct regulator_bulk_data reg[TSL2772_NUM_SUPPLIES];
>
> Since there's other changes, maybe name this 'supplies'? I think of
> 'reg' as an address.
>

Indeed there are files choosing supplies as the name.
But in iio, all regulator_bulk_data use reg (or regs, vref_reg) as the name.
So I also use reg as the name to keep consistency with others.

> >       u16 prox_data;
> >       struct tsl2772_als_info als_cur_info;
> >       struct tsl2772_settings settings;
> > @@ -697,46 +699,7 @@ static void tsl2772_disable_regulators_action(void *_data)
> >  {
> >       struct tsl2772_chip *chip = _data;
> >
> > -     regulator_disable(chip->vdd_supply);
> > -     regulator_disable(chip->vddio_supply);
> > -}
> > -
> > -static int tsl2772_enable_regulator(struct tsl2772_chip *chip,
> > -                                 struct regulator *regulator)
> > -{
> > -     int ret;
> > -
> > -     ret = regulator_enable(regulator);
> > -     if (ret < 0) {
> > -             dev_err(&chip->client->dev, "Failed to enable regulator: %d\n",
> > -                     ret);
> > -             return ret;
> > -     }
> > -
> > -     return 0;
> > -}
> > -
> > -static struct regulator *tsl2772_get_regulator(struct tsl2772_chip *chip,
> > -                                            char *name)
> > -{
> > -     struct regulator *regulator;
> > -     int ret;
> > -
> > -     regulator = devm_regulator_get(&chip->client->dev, name);
> > -     if (IS_ERR(regulator)) {
> > -             if (PTR_ERR(regulator) != -EPROBE_DEFER)
> > -                     dev_err(&chip->client->dev,
> > -                             "Failed to get %s regulator %d\n",
> > -                             name, (int)PTR_ERR(regulator));
> > -
> > -             return regulator;
> > -     }
> > -
> > -     ret = tsl2772_enable_regulator(chip, regulator);
> > -     if (ret < 0)
> > -             return ERR_PTR(ret);
> > -
> > -     return regulator;
> > +     regulator_bulk_disable(ARRAY_SIZE(chip->reg), chip->reg);
> >  }
> >
> >  static int tsl2772_chip_on(struct iio_dev *indio_dev)
> > @@ -860,6 +823,13 @@ static int tsl2772_chip_off(struct iio_dev *indio_dev)
> >       return tsl2772_write_control_reg(chip, 0x00);
> >  }
> >
> > +static void tsl2772_chip_off_action(void *data)
> > +{
> > +     struct iio_dev *indio_dev = data;
> > +
> > +     tsl2772_chip_off(indio_dev);
> > +}
> > +
> >  /**
> >   * tsl2772_invoke_change - power cycle the device to implement the user
> >   *                         parameters
> > @@ -1797,20 +1767,22 @@ static int tsl2772_probe(struct i2c_client *clientp,
> >       chip->client = clientp;
> >       i2c_set_clientdata(clientp, indio_dev);
> >
> > -     chip->vddio_supply = tsl2772_get_regulator(chip, "vddio");
> > -     if (IS_ERR(chip->vddio_supply))
> > -             return PTR_ERR(chip->vddio_supply);
> > +     chip->reg[TSL2772_SUPPLY_VDD].supply = "vdd";
> > +     chip->reg[TSL2772_SUPPLY_VDDIO].supply = "vddio";
> >
> > -     chip->vdd_supply = tsl2772_get_regulator(chip, "vdd");
> > -     if (IS_ERR(chip->vdd_supply)) {
> > -             regulator_disable(chip->vddio_supply);
> > -             return PTR_ERR(chip->vdd_supply);
> > -     }
> > +     ret = devm_regulator_bulk_get(&clientp->dev, ARRAY_SIZE(chip->reg),
> > +             chip->reg);
> > +     if (ret < 0)
> > +             return ret;
>
> Add a dev_err like the other error paths in probe function. Users can
> use the tracing subsystem to see why this failed but an error message
> in dmesg is much easier for users to find. Also be sure to check for the
> EPROBE_DEFER case.
>

I will do this in next version.

Regards,
Chuhong

> Brian