Re: [PATCH 2/2] pmbus: ltc2978: add regulator gating

From: atull
Date: Fri Aug 22 2014 - 11:38:21 EST


On Fri, 22 Aug 2014, Mark Brown wrote:

> On Thu, Aug 21, 2014 at 05:21:26PM -0500, atull@xxxxxxxxxxxxxxxxxxxxx wrote:
>
> > +config SENSORS_LTC2978_REGULATOR
> > + boolean "Regulator support for LTC2974, LTC2978, LTC3880, and LTC3883"
> > + default n
>
> No need to say default n here, it's the default default.
>
> > + depends on SENSORS_LTC2978
> > + select REGULATOR
>
> I'd expect a depends here.

Hi Mark,

Thanks for the review. I'll fix these two Kconfig issues.

>
> > +#include <linux/regulator/driver.h>
> > +#include <linux/regulator/machine.h>
>
> If you need machine.h that's suspicious... why do you need it?

It was to define 'struct regulator_init_data' which I had hardwired here
as you noted below. Will fix.

>
> > +static int ltc2978_write_pmbus_operation(struct regulator_dev *rdev, u8 value)
> > +{
> > + struct device *dev = rdev_get_dev(rdev);
> > + struct i2c_client *client = to_i2c_client(dev->parent);
> > + int ret;
> > +
> > + ret = pmbus_set_page(client, 0xff);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return i2c_smbus_write_byte_data(client, PMBUS_OPERATION, value);
> > +}
>
> This all looks very much like pmbus could use regmap and then the regmap
> helpers. I'd not insist on it though. What I would however suggest is
> that these functions should all be helpers which read the specific
> page, addresses and bits to write from the driver structure - I bet the
> code is going to be identical for most pmbus using regulators and so it
> makes sense to share it like we do with the generic regmap functions.
>
> That means that any good practice can be deployed more easily and any
> API updates only need to update the helpers.
>
> > +static struct regulator_init_data ltc2978_regulator_init = {
> > + .constraints = {
> > + .valid_ops_mask = REGULATOR_CHANGE_STATUS,
> > + },
> > +};
>
> You should not be forcing this on, you don't know what's safe on any
> given board. Allow the board to specify constraints then it has
> control.
>

Yes, this info should be from board info or device tree. I'll fix this.

Thanks!

Alan
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