On Fri, Jun 23, 2017 at 11:56:05PM +0800, Sean Wang wrote:
> On Tue, 2017-06-06 at 19:22 +0100, Mark Brown wrote:

> > > + return (regval & info->desc.enable_mask) ?
> > > + REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;

> > This isn't really a get_status() operation - it's just showing the
> > status of the enable we set. The get_status() operation is for hardware
> > that has a mechanism for reading back the current physical status of the
> > regulator, usually including things like if it's in regulation or not.

> > Also please write normal conditional statements, it helps people read
> > the code.

> for the hardware, the way for reflect the current physical physical
> has to depend on the bit reading as the bit we enable. It indeed tends
> to confuse other users and developers, we maybe can add some comments
> for this to avoid.

It's OK to just not have a get_status() operation - a lot of regulators
just can't do this and that's fine, the subsystem will cope.

> > > +static const struct of_device_id mt6380_of_match[] = {
> > > + { .compatible = "mediatek,mt6380-regulator", },
> > > + { /* sentinel */ },
> > > +};
> > > +MODULE_DEVICE_TABLE(of, mt6380_of_match);

> > Given that this driver is entirely specific to the parent PMIC there
> > should be no need for a separate compatible string, it's redundant.

> the parent of pmic is MediaTek pwrap which is possibly being used with
> various pmics such as MT6323, MT6797, MT6380 and so on. So extra
> matching we thought is required to identify which pmic is actually being
> connected.

> For those opinions, maybe we didn't get your exact point. If something
> is wrong, please kindly guide us to the right place.

It sounds like pwrap should be a bus rather than using a platform device
here? But I guess that's how things are for now so OK.

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2017-06-23 16:43:26

by Sean Wang

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Subject: Re: [PATCH 3/9] regulator: mt6380: Add support for MT6380

On Fri, 2017-06-23 at 17:14 +0100, Mark Brown wrote:
> On Fri, Jun 23, 2017 at 11:56:05PM +0800, Sean Wang wrote:
> > On Tue, 2017-06-06 at 19:22 +0100, Mark Brown wrote:
>
> > > > + return (regval & info->desc.enable_mask) ?
> > > > + REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
>
> > > This isn't really a get_status() operation - it's just showing the
> > > status of the enable we set. The get_status() operation is for hardware
> > > that has a mechanism for reading back the current physical status of the
> > > regulator, usually including things like if it's in regulation or not.
>
> > > Also please write normal conditional statements, it helps people read
> > > the code.
>
> > for the hardware, the way for reflect the current physical physical
> > has to depend on the bit reading as the bit we enable. It indeed tends
> > to confuse other users and developers, we maybe can add some comments
> > for this to avoid.
>
> It's OK to just not have a get_status() operation - a lot of regulators
> just can't do this and that's fine, the subsystem will cope.
>

understood. it seems to be better with subsystem coping. we'll remove
get_status callback.

> > > > +static const struct of_device_id mt6380_of_match[] = {
> > > > + { .compatible = "mediatek,mt6380-regulator", },
> > > > + { /* sentinel */ },
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, mt6380_of_match);
>
> > > Given that this driver is entirely specific to the parent PMIC there
> > > should be no need for a separate compatible string, it's redundant.
>
> > the parent of pmic is MediaTek pwrap which is possibly being used with
> > various pmics such as MT6323, MT6797, MT6380 and so on. So extra
> > matching we thought is required to identify which pmic is actually being
> > connected.
>
> > For those opinions, maybe we didn't get your exact point. If something
> > is wrong, please kindly guide us to the right place.
>
> It sounds like pwrap should be a bus rather than using a platform device
> here? But I guess that's how things are for now so OK.

yes, it is a bus , a proprietary bus, which is something like
encapsulation of spi and there's some protocol running on this
between master/slave.

2017-07-14 15:06:16

by Sean Wang

[permalink] [raw]

Subject: Re: [PATCH 3/9] regulator: mt6380: Add support for MT6380

On Sat, 2017-06-24 at 00:43 +0800, Sean Wang wrote:
> On Fri, 2017-06-23 at 17:14 +0100, Mark Brown wrote:
> > On Fri, Jun 23, 2017 at 11:56:05PM +0800, Sean Wang wrote:
> > > On Tue, 2017-06-06 at 19:22 +0100, Mark Brown wrote:
> >
> > > > > + return (regval & info->desc.enable_mask) ?
> > > > > + REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
> >
> > > > This isn't really a get_status() operation - it's just showing the
> > > > status of the enable we set. The get_status() operation is for hardware
> > > > that has a mechanism for reading back the current physical status of the
> > > > regulator, usually including things like if it's in regulation or not.
> >
> > > > Also please write normal conditional statements, it helps people read
> > > > the code.
> >
> > > for the hardware, the way for reflect the current physical physical
> > > has to depend on the bit reading as the bit we enable. It indeed tends
> > > to confuse other users and developers, we maybe can add some comments
> > > for this to avoid.
> >
> > It's OK to just not have a get_status() operation - a lot of regulators
> > just can't do this and that's fine, the subsystem will cope.
> >
>
> understood. it seems to be better with subsystem coping. we'll remove
> get_status callback.
>

Hi, Mark

We usually want to use /sys/class/regulator/regulator.*/status to get
actual status from hardware, but if we remove the get_status(), the
status entry under sysfs would be gone. So could I keep the get_status
callback in this driver ?

Sean

> > > > > +static const struct of_device_id mt6380_of_match[] = {
> > > > > + { .compatible = "mediatek,mt6380-regulator", },
> > > > > + { /* sentinel */ },
> > > > > +};
> > > > > +MODULE_DEVICE_TABLE(of, mt6380_of_match);
> >
> > > > Given that this driver is entirely specific to the parent PMIC there
> > > > should be no need for a separate compatible string, it's redundant.
> >
> > > the parent of pmic is MediaTek pwrap which is possibly being used with
> > > various pmics such as MT6323, MT6797, MT6380 and so on. So extra
> > > matching we thought is required to identify which pmic is actually being
> > > connected.
> >
> > > For those opinions, maybe we didn't get your exact point. If something
> > > is wrong, please kindly guide us to the right place.
> >
> > It sounds like pwrap should be a bus rather than using a platform device
> > here? But I guess that's how things are for now so OK.
>
> yes, it is a bus , a proprietary bus, which is something like
> encapsulation of spi and there's some protocol running on this
> between master/slave.
>
>
> _______________________________________________
> Linux-mediatek mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

2017-07-14 15:14:51

by Mark Brown

[permalink] [raw]

Subject: Re: [PATCH 3/9] regulator: mt6380: Add support for MT6380

On Fri, Jul 14, 2017 at 11:06:08PM +0800, Sean Wang wrote:

> We usually want to use /sys/class/regulator/regulator.*/status to get
> actual status from hardware, but if we remove the get_status(), the
> status entry under sysfs would be gone. So could I keep the get_status
> callback in this driver ?

If the device doesn't support physical status readback it shouldn't have
a get_status() callback.

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