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

[jckuo]

Thanks Thierry.

Reviewed-by: JC Kuo <jc...@nvidia.com>

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 <tred...@nvidia.com>

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 <tred...@nvidia.com>
---
   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,