Re: [PATCH v3 1/3] hwmon: (pmbus) Use driver specific ops if they exist

Marten Lindahl
2022-04-28T13:00:58Z

On Wed, Apr 27, 2022 at 03:26:56PM +0200, Guenter Roeck wrote:
> On Wed, Apr 27, 2022 at 03:02:11PM +0200, Mårten Lindahl wrote:
> > Pmbus drivers using the default pmbus_regulator_ops for the enable/
> > disable/is_enabled functions will use the standard pmbus core functions
> > pmbus_read/write_byte_data. This could potentially influence some
> > specific regulator chips that for example need a time delay before each
> > data access.
> >
> > Lets add support for drivers to use chip specific read/write operations
> > when using the standard pmbus_regulator_ops.
>
> The subject is misleading. It should be something like "introduce and
> use write_byte_data callback". Also, existing code calling
> pmbus_write_byte_data() should call _pmbus_write_byte_data() instead.
> This applies to pmbus_update_fan() and pmbus_get_boolean().

Ok, I will change the subject to your suggestion, and change those two
functions. Thanks!

Kind regards
Mårten
>
> Thanks,
> Guenter
>
> >
> > Signed-off-by: Mårten Lindahl <marten.lindahl@axis.com>
> > ---
> > drivers/hwmon/pmbus/pmbus.h | 2 ++
> > drivers/hwmon/pmbus/pmbus_core.c | 58 +++++++++++++++++++++-----------
> > 2 files changed, 40 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
> > index e74b6ef070f3..c031a9700ace 100644
> > --- a/drivers/hwmon/pmbus/pmbus.h
> > +++ b/drivers/hwmon/pmbus/pmbus.h
> > @@ -438,6 +438,8 @@ struct pmbus_driver_info {
> > int (*read_byte_data)(struct i2c_client *client, int page, int reg);
> > int (*read_word_data)(struct i2c_client *client, int page, int phase,
> > int reg);
> > + int (*write_byte_data)(struct i2c_client *client, int page, int reg,
> > + u8 byte);
> > int (*write_word_data)(struct i2c_client *client, int page, int reg,
> > u16 word);
> > int (*write_byte)(struct i2c_client *client, int page, u8 value);
> > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
> > index b2618b1d529e..1b0728c3c7d8 100644
> > --- a/drivers/hwmon/pmbus/pmbus_core.c
> > +++ b/drivers/hwmon/pmbus/pmbus_core.c
> > @@ -384,25 +384,6 @@ int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value)
> > }
> > EXPORT_SYMBOL_NS_GPL(pmbus_write_byte_data, PMBUS);
> >
> > -int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
> > - u8 mask, u8 value)
> > -{
> > - unsigned int tmp;
> > - int rv;
> > -
> > - rv = pmbus_read_byte_data(client, page, reg);
> > - if (rv < 0)
> > - return rv;
> > -
> > - tmp = (rv & ~mask) | (value & mask);
> > -
> > - if (tmp != rv)
> > - rv = pmbus_write_byte_data(client, page, reg, tmp);
> > -
> > - return rv;
> > -}
> > -EXPORT_SYMBOL_NS_GPL(pmbus_update_byte_data, PMBUS);
> > -
> > /*
> > * _pmbus_read_byte_data() is similar to pmbus_read_byte_data(), but checks if
> > * a device specific mapping function exists and calls it if necessary.
> > @@ -421,6 +402,43 @@ static int _pmbus_read_byte_data(struct i2c_client *client, int page, int reg)
> > return pmbus_read_byte_data(client, page, reg);
> > }
> >
> > +/*
> > + * _pmbus_write_byte_data() is similar to pmbus_write_byte_data(), but checks if
> > + * a device specific mapping function exists and calls it if necessary.
> > + */
> > +static int _pmbus_write_byte_data(struct i2c_client *client, int page, int reg, u8 value)
> > +{
> > + struct pmbus_data *data = i2c_get_clientdata(client);
> > + const struct pmbus_driver_info *info = data->info;
> > + int status;
> > +
> > + if (info->write_byte_data) {
> > + status = info->write_byte_data(client, page, reg, value);
> > + if (status != -ENODATA)
> > + return status;
> > + }
> > + return pmbus_write_byte_data(client, page, reg, value);
> > +}
> > +
> > +int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
> > + u8 mask, u8 value)
> > +{
> > + unsigned int tmp;
> > + int rv;
> > +
> > + rv = _pmbus_read_byte_data(client, page, reg);
> > + if (rv < 0)
> > + return rv;
> > +
> > + tmp = (rv & ~mask) | (value & mask);
> > +
> > + if (tmp != rv)
> > + rv = _pmbus_write_byte_data(client, page, reg, tmp);
> > +
> > + return rv;
> > +}
> > +EXPORT_SYMBOL_NS_GPL(pmbus_update_byte_data, PMBUS);
> > +
> > static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int page,
> > int reg)
> > {
> > @@ -2396,7 +2414,7 @@ static int pmbus_regulator_is_enabled(struct regulator_dev *rdev)
> > int ret;
> >
> > mutex_lock(&data->update_lock);
> > - ret = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
> > + ret = _pmbus_read_byte_data(client, page, PMBUS_OPERATION);
> > mutex_unlock(&data->update_lock);
> >
> > if (ret < 0)