Re: [PATCH 4/5] phy: tegra: xusb: Add support for power supplies

[jckuo <jckuo@xxxxxxxxxx>]

Thanks Thierry.

Reviewed-by: JC Kuo <jckuo@xxxxxxxxxx>

On 1/28/19 4:00 PM, Thierry Reding wrote:
> On Mon, Jan 28, 2019 at 03:22:09PM +0800, jckuo wrote:
> > Hi Thierry,
> >
> > I think any non-zero return value of
> > regulator_bulk_enable()/devm_regulator_bulk_get() means error.
> >
> > Thanks,
> >
> > JC
> Theoretically I think only regulator_bulk_enable() could return a
> positive value, but even so it never will in practice because all of the
> regulator_enable() (see _regulator_enable()) calls will only ever return
> negative error codes.
>
> I can change this and resend if you have strong concerns about this
> possibly missing legitimate error cases.
>
> Thierry
>
> > On 1/25/19 7:25 PM, Thierry Reding wrote:
> > > From: Thierry Reding <treding@xxxxxxxxxx>
> > >
> > > Support enabling various supplies needed to provide power to the PLLs
> > > and logic used to drive the USB, PCI and SATA pads.
> > >
> > > Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
> > > ---
> > >    drivers/phy/tegra/xusb.c | 34 +++++++++++++++++++++++++++++++++-
> > >    drivers/phy/tegra/xusb.h |  5 +++++
> > >    2 files changed, 38 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
> > > index 57a2d08ef6da..e510629f4f1c 100644
> > > --- a/drivers/phy/tegra/xusb.c
> > > +++ b/drivers/phy/tegra/xusb.c
> > > @@ -864,6 +864,7 @@ static int tegra_xusb_padctl_probe(struct platform_device *pdev)
> > >    	struct tegra_xusb_padctl *padctl;
> > >    	const struct of_device_id *match;
> > >    	struct resource *res;
> > > +	unsigned int i;
> > >    	int err;
> > >    	/* for backwards compatibility with old device trees */
> > > @@ -901,14 +902,38 @@ static int tegra_xusb_padctl_probe(struct platform_device *pdev)
> > >    		goto remove;
> > >    	}
> > > +	padctl->supplies = devm_kcalloc(&pdev->dev, padctl->soc->num_supplies,
> > > +					sizeof(*padctl->supplies), GFP_KERNEL);
> > > +	if (!padctl->supplies) {
> > > +		err = -ENOMEM;
> > > +		goto remove;
> > > +	}
> > > +
> > > +	for (i = 0; i < padctl->soc->num_supplies; i++)
> > > +		padctl->supplies[i].supply = padctl->soc->supply_names[i];
> > > +
> > > +	err = devm_regulator_bulk_get(&pdev->dev, padctl->soc->num_supplies,
> > > +				      padctl->supplies);
> > > +	if (err < 0) {
> > > +		dev_err(&pdev->dev, "failed to get regulators: %d\n", err);
> > > +		goto remove;
> > > +	}
> > > +
> > >    	err = reset_control_deassert(padctl->rst);
> > >    	if (err < 0)
> > >    		goto remove;
> > > +	err = regulator_bulk_enable(padctl->soc->num_supplies,
> > > +				    padctl->supplies);
> > > +	if (err < 0) {
> > > +		dev_err(&pdev->dev, "failed to enable supplies: %d\n", err);
> > > +		goto reset;
> > > +	}
> > > +
> > >    	err = tegra_xusb_setup_pads(padctl);
> > >    	if (err < 0) {
> > >    		dev_err(&pdev->dev, "failed to setup pads: %d\n", err);
> > > -		goto reset;
> > > +		goto power_down;
> > >    	}
> > >    	err = tegra_xusb_setup_ports(padctl);
> > > @@ -921,6 +946,8 @@ static int tegra_xusb_padctl_probe(struct platform_device *pdev)
> > >    remove_pads:
> > >    	tegra_xusb_remove_pads(padctl);
> > > +power_down:
> > > +	regulator_bulk_disable(padctl->soc->num_supplies, padctl->supplies);
> > >    reset:
> > >    	reset_control_assert(padctl->rst);
> > >    remove:
> > > @@ -936,6 +963,11 @@ static int tegra_xusb_padctl_remove(struct platform_device *pdev)
> > >    	tegra_xusb_remove_ports(padctl);
> > >    	tegra_xusb_remove_pads(padctl);
> > > +	err = regulator_bulk_disable(padctl->soc->num_supplies,
> > > +				     padctl->supplies);
> > > +	if (err < 0)
> > > +		dev_err(&pdev->dev, "failed to disable supplies: %d\n", err);
> > > +
> > >    	err = reset_control_assert(padctl->rst);
> > >    	if (err < 0)
> > >    		dev_err(&pdev->dev, "failed to assert reset: %d\n", err);
> > > diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
> > > index bb60fc09c752..5d5d22f6cb41 100644
> > > --- a/drivers/phy/tegra/xusb.h
> > > +++ b/drivers/phy/tegra/xusb.h
> > > @@ -370,6 +370,9 @@ struct tegra_xusb_padctl_soc {
> > >    	} ports;
> > >    	const struct tegra_xusb_padctl_ops *ops;
> > > +
> > > +	const char * const *supply_names;
> > > +	unsigned int num_supplies;
> > >    };
> > >    struct tegra_xusb_padctl {
> > > @@ -393,6 +396,8 @@ struct tegra_xusb_padctl {
> > >    	unsigned int enable;
> > >    	struct clk *clk;
> > > +
> > > +	struct regulator_bulk_data *supplies;
> > >    };
> > >    static inline void padctl_writel(struct tegra_xusb_padctl *padctl, u32 value,