Re: [Patch V2 03/18] phy: tegra: xusb: Add usb-role-switch support

[Nagarjuna Kristam <nkristam@xxxxxxxxxx>]

On 26-12-2019 12:12, JC Kuo wrote:
> On 12/18/19 5:16 PM, Nagarjuna Kristam wrote:
> > If usb-role-switch property is present in USB 2 port, register
> > usb-role-switch to receive usb role changes.
> >
> > Signed-off-by: Nagarjuna Kristam <nkristam@xxxxxxxxxx>
> > ---
> > V2:
> >   - Removed dev_set_drvdata for port->dev.
> >   - Added of_platform_depopulate during error handling and driver removal.
> > ---
> >   drivers/phy/tegra/Kconfig |  1 +
> >   drivers/phy/tegra/xusb.c  | 42 ++++++++++++++++++++++++++++++++++++++++++
> >   drivers/phy/tegra/xusb.h  |  3 +++
> >   3 files changed, 46 insertions(+)
> >
> > diff --git a/drivers/phy/tegra/Kconfig b/drivers/phy/tegra/Kconfig
> > index f9817c3..df07c4d 100644
> > --- a/drivers/phy/tegra/Kconfig
> > +++ b/drivers/phy/tegra/Kconfig
> > @@ -2,6 +2,7 @@
> >   config PHY_TEGRA_XUSB
> >   	tristate "NVIDIA Tegra XUSB pad controller driver"
> >   	depends on ARCH_TEGRA
> > +	select USB_CONN_GPIO
> >   	help
> >   	  Choose this option if you have an NVIDIA Tegra SoC.
> >   
> > diff --git a/drivers/phy/tegra/xusb.c b/drivers/phy/tegra/xusb.c
> > index f98ec39..dc00b42 100644
> > --- a/drivers/phy/tegra/xusb.c
> > +++ b/drivers/phy/tegra/xusb.c
> > @@ -523,6 +523,7 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
> >   	port->dev.type = &tegra_xusb_port_type;
> >   	port->dev.of_node = of_node_get(np);
> >   	port->dev.parent = padctl->dev;
> > +	port->dev.driver = padctl->dev->driver;
> >   
> >   	err = dev_set_name(&port->dev, "%s-%u", name, index);
> >   	if (err < 0)
> > @@ -541,6 +542,10 @@ static int tegra_xusb_port_init(struct tegra_xusb_port *port,
> >   
> >   static void tegra_xusb_port_unregister(struct tegra_xusb_port *port)
> >   {
> > +	if (!IS_ERR_OR_NULL(port->usb_role_sw)) {
> > +		of_platform_depopulate(&port->dev);
> > +		usb_role_switch_unregister(port->usb_role_sw);
> > +	}
> >   	device_unregister(&port->dev);
> >   }
> >   
> > @@ -551,11 +556,42 @@ static const char *const modes[] = {
> >   	[USB_DR_MODE_OTG] = "otg",
> >   };
> >   
> > +static int tegra_xusb_role_sw_set(struct device *dev, enum usb_role role)
> > +{
> > +	dev_dbg(dev, "%s calling notifier for role is %d\n", __func__, role);
> > +
> > +	return 0;
> > +}
> > +
> > +static int tegra_xusb_setup_usb_role_switch(struct tegra_xusb_port *port)
> > +{
> > +	int err = 0;
> > +	struct usb_role_switch_desc role_sx_desc = {
> > +					.set = tegra_xusb_role_sw_set,
> > +					.fwnode = dev_fwnode(&port->dev),
> > +						   };
> > +
> > +	port->usb_role_sw = usb_role_switch_register(&port->dev,
> > +						&role_sx_desc);
> > +	if (IS_ERR(port->usb_role_sw)) {
> > +		err = PTR_ERR(port->usb_role_sw);
> > +		if (err != EPROBE_DEFER)
> > +			dev_err(&port->dev, "Failed to register USB role SW: %d",
> > +				err);
> > +	}
> > +
> > +	/* populate connector entry */
> > +	of_platform_populate(port->dev.of_node, NULL, NULL, &port->dev);
> > +
> > +	return err;
> > +}
> > +
> >   static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
> >   {
> >   	struct tegra_xusb_port *port = &usb2->base;
> >   	struct device_node *np = port->dev.of_node;
> >   	const char *mode;
> > +	int err;
> >   
> >   	usb2->internal = of_property_read_bool(np, "nvidia,internal");
> >   
> > @@ -572,6 +608,12 @@ static int tegra_xusb_usb2_port_parse_dt(struct tegra_xusb_usb2_port *usb2)
> >   		usb2->mode = USB_DR_MODE_HOST;
> >   	}
> >   
> "usb-role-switch" is not required for host mode port. If a otg or a peripheral
> port doesn't have "usb-role-switch" property, .probe() should abort.
>
> Thanks,
> JC

Yes, will add the checks accordingly.
-nagarjuna

> > +	if (of_property_read_bool(np, "usb-role-switch")) {
> > +		err = tegra_xusb_setup_usb_role_switch(port);
> > +		if (err < 0)
> > +			return err;
> > +	}
> > +
> >   	usb2->supply = devm_regulator_get(&port->dev, "vbus");
> >   	return PTR_ERR_OR_ZERO(usb2->supply);
> >   }
> > diff --git a/drivers/phy/tegra/xusb.h b/drivers/phy/tegra/xusb.h
> > index da94fcc..9f27899 100644
> > --- a/drivers/phy/tegra/xusb.h
> > +++ b/drivers/phy/tegra/xusb.h
> > @@ -12,6 +12,7 @@
> >   #include <linux/workqueue.h>
> >   
> >   #include <linux/usb/otg.h>
> > +#include <linux/usb/role.h>
> >   
> >   /* legacy entry points for backwards-compatibility */
> >   int tegra_xusb_padctl_legacy_probe(struct platform_device *pdev);
> > @@ -266,6 +267,8 @@ struct tegra_xusb_port {
> >   	struct list_head list;
> >   	struct device dev;
> >   
> > +	struct usb_role_switch *usb_role_sw;
> > +
> >   	const struct tegra_xusb_port_ops *ops;
> >   };
> >