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

JC Kuo
2019-12-26T06:42:40Z

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@nvidia.com>
> ---
> 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

> + 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;
> };
>
>