RE: [PATCH] power: qcom_smbb: Add otg regulator for control of vbus

[Bird, Tim]

________________________________________
On Monday, October 26, 2015 4:17 AM, Mark Rutland wrote:
>
> On Thu, Oct 22, 2015 at 02:12:17PM -0700, Tim Bird wrote:
> > Add a regulator to control the OTG chargepath switch.  The OTG
> > switch gets its power from pm8941_5vs1, and that should be expressed
> > as an usb_otg_in-supply property in the DT node for the charger driver.
> > The regulator name is "otg".  This is used by USB code to control VBUS
> > direction.
> >
> > Signed-off-by: Tim Bird <tim.bird@xxxxxxxxxxxxxx>
> > ---
> >  .../devicetree/bindings/power_supply/qcom_smbb.txt | 20 ++++++
> >  drivers/power/qcom_smbb.c                          | 74 ++++++++++++++++++++++
> >  2 files changed, 94 insertions(+)
>
> What tree is this based on? I couldn't spot this in origin/master.
>

This is in linux-next.  This is a new binding and charger driver that's
in Sebastien Reichel's Power Supply driver tree.

>
> > diff --git a/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt b/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt
> > index 65b88fa..dc0f91d 100644
> > --- a/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt
> > +++ b/Documentation/devicetree/bindings/power_supply/qcom_smbb.txt
> > @@ -105,6 +105,23 @@ PROPERTIES
> >                 regulation must be done externally to fully comply with
> >                 the JEITA safety guidelines if this flag is set.
> >
> > +- usb_otg_in-supply:
> > +  Usage: optional
> > +  Value type: <phandle>
> > +  Description: Reference to the regulator supplying power to the USB_OTG_IN
> > +               pin.
>
> s/_/-/ in property names, please.

OK.

>
>
> > +
> > +child nodes:
> > +- otg:
> > +  Usage: optional
> > +  Description: This node is used to define a regulator which is used by
> > +               other parts of the system to control the direction of VBUS
> > +               voltage - specifically: whether to supply voltage to VBUS for
> > +               host mode operation of the OTG port. The driver registers a
> > +               regulator with this name, which can be looked up by string.
> > +               Alternatively, you can add a DT label, which can then be
> > +               referenced by phandle.
> > +
>
> We shouldn't specify the behaviours of the driver/linux here, just the
> hardware.

OK - I'll reword this.

> I'm a little confused by how this is used, but I suspect that'll be
> cleared up when I see the rest of the binding that this is based on.

OK - thanks for the review.
 -- Tim

> Thanks,
> Mark.
>
> >  EXAMPLE
> >  charger@1000 {
> >         compatible = "qcom,pm8941-charger";
> > @@ -128,4 +145,7 @@ charger@1000 {
> >
> >         qcom,fast-charge-current-limit = <1000000>;
> >         qcom,dc-charge-current-limit = <1000000>;
> > +       usb_otg_in-supply = <&pm8941_5vs1>;
> > +
> > +       otg {};
> >  };
> > diff --git a/drivers/power/qcom_smbb.c b/drivers/power/qcom_smbb.c
> > index 0dabfe8..fa2983a 100644
> > --- a/drivers/power/qcom_smbb.c
> > +++ b/drivers/power/qcom_smbb.c
> > @@ -34,6 +34,9 @@
> >  #include <linux/power_supply.h>
> >  #include <linux/regmap.h>
> >  #include <linux/slab.h>
> > +#include <linux/regulator/driver.h>
> > +#include <linux/regulator/machine.h>
> > +#include <linux/regulator/of_regulator.h>
> >
> >  #define SMBB_CHG_VMAX                0x040
> >  #define SMBB_CHG_VSAFE               0x041
> > @@ -71,6 +74,8 @@
> >  #define BTC_CTRL_HOT_EXT_N   BIT(0)
> >
> >  #define SMBB_USB_IMAX                0x344
> > +#define SMBB_USB_OTG_CTL     0x348
> > +#define OTG_CTL_EN           BIT(0)
> >  #define SMBB_USB_ENUM_TIMER_STOP 0x34e
> >  #define ENUM_TIMER_STOP              BIT(0)
> >  #define SMBB_USB_SEC_ACCESS  0x3d0
> > @@ -123,6 +128,9 @@ struct smbb_charger {
> >       struct power_supply *dc_psy;
> >       struct power_supply *bat_psy;
> >       struct regmap *regmap;
> > +
> > +     struct regulator_desc otg_rdesc;
> > +     struct regulator_dev *otg_reg;
> >  };
> >
> >  static int smbb_vbat_weak_fn(unsigned int index)
> > @@ -778,12 +786,56 @@ static const struct power_supply_desc dc_psy_desc = {
> >       .property_is_writeable = smbb_charger_writable_property,
> >  };
> >
> > +static int smbb_chg_otg_enable(struct regulator_dev *rdev)
> > +{
> > +     struct smbb_charger *chg = rdev_get_drvdata(rdev);
> > +     int rc;
> > +
> > +     rc = regmap_update_bits(chg->regmap, chg->addr + SMBB_USB_OTG_CTL,
> > +                             OTG_CTL_EN, OTG_CTL_EN);
> > +     if (rc)
> > +             dev_err(chg->dev, "failed to update OTG_CTL\n");
> > +     return rc;
> > +}
> > +
> > +static int smbb_chg_otg_disable(struct regulator_dev *rdev)
> > +{
> > +     struct smbb_charger *chg = rdev_get_drvdata(rdev);
> > +     int rc;
> > +
> > +     rc = regmap_update_bits(chg->regmap, chg->addr + SMBB_USB_OTG_CTL,
> > +                             OTG_CTL_EN, 0);
> > +     if (rc)
> > +             dev_err(chg->dev, "failed to update OTG_CTL\n");
> > +     return rc;
> > +}
> > +
> > +static int smbb_chg_otg_is_enabled(struct regulator_dev *rdev)
> > +{
> > +     struct smbb_charger *chg = rdev_get_drvdata(rdev);
> > +     unsigned int value = 0;
> > +     int rc;
> > +
> > +     rc = regmap_read(chg->regmap, chg->addr + SMBB_USB_OTG_CTL, &value);
> > +     if (rc)
> > +             dev_err(chg->dev, "failed to read OTG_CTL\n");
> > +
> > +     return !!(value & OTG_CTL_EN);
> > +}
> > +
> > +static struct regulator_ops smbb_chg_otg_ops = {
> > +     .enable = smbb_chg_otg_enable,
> > +     .disable = smbb_chg_otg_disable,
> > +     .is_enabled = smbb_chg_otg_is_enabled,
> > +};
> > +
> >  static int smbb_charger_probe(struct platform_device *pdev)
> >  {
> >       struct power_supply_config bat_cfg = {};
> >       struct power_supply_config usb_cfg = {};
> >       struct power_supply_config dc_cfg = {};
> >       struct smbb_charger *chg;
> > +     struct regulator_config config = { };
> >       int rc, i;
> >
> >       chg = devm_kzalloc(&pdev->dev, sizeof(*chg), GFP_KERNEL);
> > @@ -884,6 +936,28 @@ static int smbb_charger_probe(struct platform_device *pdev)
> >               }
> >       }
> >
> > +     /*
> > +      * otg regulator is used to control VBUS voltage direction
> > +      * when USB switches between host and gadget mode
> > +      */
> > +     chg->otg_rdesc.id = -1;
> > +     chg->otg_rdesc.name = "otg";
> > +     chg->otg_rdesc.ops = &smbb_chg_otg_ops;
> > +     chg->otg_rdesc.owner = THIS_MODULE;
> > +     chg->otg_rdesc.type = REGULATOR_VOLTAGE;
> > +     chg->otg_rdesc.supply_name = "usb_otg_in";
> > +     chg->otg_rdesc.fixed_uV = 5000000;
> > +     chg->otg_rdesc.n_voltages = 1;
> > +     chg->otg_rdesc.of_match = "otg";
> > +
> > +     config.dev = &pdev->dev;
> > +     config.driver_data = chg;
> > +
> > +     chg->otg_reg = devm_regulator_register(&pdev->dev, &chg->otg_rdesc,
> > +                                            &config);
> > +     if (IS_ERR(chg->otg_reg))
> > +             return PTR_ERR(chg->otg_reg);
> > +
> >       chg->jeita_ext_temp = of_property_read_bool(pdev->dev.of_node,
> >                       "qcom,jeita-extended-temp-range");
> >
> > --
> > 1.8.2.2
> >
--
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