Re: [PATCH v7 3/3] xhci: tegra: USB2 pad power controls

[Jon Hunter]

On 11/11/2022 10:18, Jim Lin wrote:
> From: Petlozu Pravareshwar <petlozup@xxxxxxxxxx>
>
> Program USB2 pad PD controls during port connect/disconnect, port
> suspend/resume, and test mode, to reduce power consumption on
> disconnect or suspend.
>
> Signed-off-by: Petlozu Pravareshwar <petlozup@xxxxxxxxxx>
> Co-developed-by: Jim Lin <jilin@xxxxxxxxxx>
> Signed-off-by: Jim Lin <jilin@xxxxxxxxxx>
>
> ---
> v2: Fix issue that wrong tegra->phys[] may be accessed on tegra124
> v3: No change on copyright
> v4: Remove hcd_to_tegra_xusb() function which is used only once.
> v5: Update .hub_control in tegra_xhci_overrides (xhci-tegra.c)
>      Invoke xhci_hub_control() directly (xhci-tegra.c)
> v6: Change author to Petlozu
>      Changed from u32 to u8 for variable enable_utmi_pad_after_lp0_exit
>      Modified tegra_xhci_disable_phy_wake(), tegra_xhci_program_utmi_power_lp0_exit(),
>      tegra_xhci_hub_control()
> v7: no change
>
>   drivers/usb/host/xhci-tegra.c | 125 ++++++++++++++++++++++++++++++++++
>   1 file changed, 125 insertions(+)
>
> diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
> index c8af2cd2216d..b5ed06ddbbac 100644
> --- a/drivers/usb/host/xhci-tegra.c
> +++ b/drivers/usb/host/xhci-tegra.c
> @@ -274,6 +274,7 @@ struct tegra_xusb {
>   
>   	bool suspended;
>   	struct tegra_xusb_context context;
> +	u8 lp0_utmi_pad_mask;
>   };
>   
>   static struct hc_driver __read_mostly tegra_xhci_hc_driver;
> @@ -1951,10 +1952,24 @@ static void tegra_xhci_disable_phy_wake(struct tegra_xusb *tegra)
>   	struct tegra_xusb_padctl *padctl = tegra->padctl;
>   	unsigned int i;
>   
> +	for (i = 0; i < tegra->num_usb_phys; i++) {
> +		struct phy *phy = tegra_xusb_get_phy(tegra, "usb2", i);
> +
> +		if (!phy)
> +			continue;
> +
> +		if (tegra_xusb_padctl_remote_wake_detected(padctl, phy))
> +			tegra_phy_xusb_utmi_pad_power_on(phy);
> +	}
> +
>   	for (i = 0; i < tegra->num_phys; i++) {
>   		if (!tegra->phys[i])
>   			continue;
>   
> +		if (tegra_xusb_padctl_remote_wake_detected(padctl, tegra->phys[i]))
> +			dev_dbg(tegra->dev, "%pOF remote wake detected\n",
> +				tegra->phys[i]->dev.of_node);
> +
>   		tegra_xusb_padctl_disable_phy_wake(padctl, tegra->phys[i]);
>   	}
>   }
> @@ -1972,6 +1987,28 @@ static void tegra_xhci_disable_phy_sleepwalk(struct tegra_xusb *tegra)
>   	}
>   }
>   
> +static void tegra_xhci_program_utmi_power_lp0_exit(struct tegra_xusb *tegra)
> +{
> +	unsigned int i, index_to_usb2;
> +	struct phy *phy;
> +
> +	for (i = 0; i < tegra->soc->num_types; i++) {
> +		if (strcmp(tegra->soc->phy_types[i].name, "usb2") == 0)
> +			index_to_usb2 = i;
> +	}
> +
> +	for (i = 0; i < tegra->num_usb_phys; i++) {
> +		if (!is_host_mode_phy(tegra, index_to_usb2, i))
> +			continue;
> +
> +		phy = tegra_xusb_get_phy(tegra, "usb2", i);
> +		if (tegra->lp0_utmi_pad_mask & BIT(i))
> +			tegra_phy_xusb_utmi_pad_power_on(phy);
> +		else
> +			tegra_phy_xusb_utmi_pad_power_down(phy);
> +	}
> +}
> +
>   static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
>   {
>   	struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
> @@ -1980,6 +2017,7 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
>   	unsigned int i;
>   	int err;
>   	u32 usbcmd;
> +	u32 portsc;
>   
>   	dev_dbg(dev, "entering ELPG\n");
>   
> @@ -1993,6 +2031,15 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
>   		goto out;
>   	}
>   
> +	for (i = 0; i < tegra->num_usb_phys; i++) {
> +		if (!xhci->usb2_rhub.ports[i])
> +			continue;
> +		portsc = readl(xhci->usb2_rhub.ports[i]->addr);
> +		tegra->lp0_utmi_pad_mask &= ~BIT(i);
> +		if (((portsc & PORT_PLS_MASK) == XDEV_U3) || ((portsc & DEV_SPEED_MASK) == XDEV_FS))
> +			tegra->lp0_utmi_pad_mask |= BIT(i);
> +	}
> +
>   	err = xhci_suspend(xhci, wakeup);
>   	if (err < 0) {
>   		dev_err(tegra->dev, "failed to suspend XHCI: %d\n", err);
> @@ -2066,6 +2113,8 @@ static int tegra_xusb_exit_elpg(struct tegra_xusb *tegra, bool runtime)
>   
>   		phy_power_on(tegra->phys[i]);
>   	}
> +	if (tegra->suspended)
> +		tegra_xhci_program_utmi_power_lp0_exit(tegra);
>   
>   	tegra_xusb_config(tegra);
>   	tegra_xusb_restore_context(tegra);
> @@ -2437,8 +2486,84 @@ static int tegra_xhci_setup(struct usb_hcd *hcd)
>   	return xhci_gen_setup(hcd, tegra_xhci_quirks);
>   }
>   
> +static int tegra_xhci_hub_control(struct usb_hcd *hcd, u16 type_req, u16 value, u16 index,
> +				  char *buf, u16 length)
> +{
> +	struct tegra_xusb *tegra = dev_get_drvdata(hcd->self.controller);
> +	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> +	struct xhci_hub *rhub;
> +	struct xhci_bus_state *bus_state;
> +	int port = (index & 0xff) - 1;
> +	unsigned int i;
> +	struct xhci_port **ports;
> +	u32 portsc;
> +	int ret;
> +	struct phy *phy;
> +
> +	rhub = &xhci->usb2_rhub;
> +	bus_state = &rhub->bus_state;
> +	if (bus_state->resuming_ports && hcd->speed == HCD_USB2) {
> +		ports = rhub->ports;
> +		i = rhub->num_ports;
> +		while (i--) {
> +			if (!test_bit(i, &bus_state->resuming_ports))
> +				continue;
> +			portsc = readl(ports[i]->addr);
> +			if ((portsc & PORT_PLS_MASK) == XDEV_RESUME)
> +				tegra_phy_xusb_utmi_pad_power_on(
> +					tegra_xusb_get_phy(tegra, "usb2", (int) i));
> +		}
> +	}
> +
> +	if (hcd->speed == HCD_USB2) {
> +		phy = tegra_xusb_get_phy(tegra, "usb2", port);
> +		if ((type_req == ClearPortFeature) && (value == USB_PORT_FEAT_SUSPEND)) {
> +			if (!index || index > rhub->num_ports)
> +				return -EPIPE;
> +			tegra_phy_xusb_utmi_pad_power_on(phy);
> +		}
> +		if ((type_req == SetPortFeature) && (value == USB_PORT_FEAT_RESET)) {
> +			if (!index || index > rhub->num_ports)
> +				return -EPIPE;
> +			ports = rhub->ports;
> +			portsc = readl(ports[port]->addr);
> +			if (portsc & PORT_CONNECT)
> +				tegra_phy_xusb_utmi_pad_power_on(phy);
> +		}
> +	}
> +
> +	ret = xhci_hub_control(hcd, type_req, value, index, buf, length);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (hcd->speed == HCD_USB2) {
> +		/* Use phy where we set previously */
> +		if ((type_req == SetPortFeature) && (value == USB_PORT_FEAT_SUSPEND))
> +			/* We don't suspend the PAD while HNP role swap happens on the OTG port */
> +			if (!((hcd->self.otg_port == (port + 1)) && hcd->self.b_hnp_enable))
> +				tegra_phy_xusb_utmi_pad_power_down(phy);
> +
> +		if ((type_req == ClearPortFeature) && (value == USB_PORT_FEAT_C_CONNECTION)) {
> +			ports = rhub->ports;
> +			portsc = readl(ports[port]->addr);
> +			if (!(portsc & PORT_CONNECT)) {
> +				/* We don't suspend the PAD while HNP role swap happens on the OTG
> +				 * port
> +				 */
> +				if (!((hcd->self.otg_port == (port + 1)) && hcd->self.b_hnp_enable))
> +					tegra_phy_xusb_utmi_pad_power_down(phy);
> +			}
> +		}
> +		if ((type_req == SetPortFeature) && (value == USB_PORT_FEAT_TEST))
> +			tegra_phy_xusb_utmi_pad_power_on(phy);
> +	}
> +
> +	return ret;
> +}
> +
>   static const struct xhci_driver_overrides tegra_xhci_overrides __initconst = {
>   	.reset = tegra_xhci_setup,
> +	.hub_control = tegra_xhci_hub_control,
>   };
>   
>   static int __init tegra_xusb_init(void)

Reviewed-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>

Thanks
Jon

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nvpublic