[PATCH] xhci: tegra: USB2 pad power controls

[Jim Lin]

Program USB2 pad PD controls during port connect/disconnect, port
suspend/resume, to reduce power consumption on disconnect or suspend.

Signed-off-by: Jim Lin <jilin@xxxxxxxxxx>
---
 drivers/usb/host/xhci-tegra.c | 130 +++++++++++++++++++++++++++++++++-
 1 file changed, 129 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/host/xhci-tegra.c b/drivers/usb/host/xhci-tegra.c
index 1ed46642abd5..9ebd68373bd5 100644
--- a/drivers/usb/host/xhci-tegra.c
+++ b/drivers/usb/host/xhci-tegra.c
@@ -189,6 +189,13 @@ struct tegra_xusb_context_soc {
 	} fpci;
 };
 
+enum tegra_xhci_phy_type {
+	USB3_PHY,
+	USB2_PHY,
+	HSIC_PHY,
+	MAX_PHY_TYPES,
+};
+
 struct tegra_xusb_soc {
 	const char *firmware;
 	const char * const *supply_names;
@@ -274,9 +281,17 @@ struct tegra_xusb {
 
 	bool suspended;
 	struct tegra_xusb_context context;
+	u32 enable_utmi_pad_after_lp0_exit;
 };
 
 static struct hc_driver __read_mostly tegra_xhci_hc_driver;
+static int (*original_xhci_hub_control)(struct usb_hcd *hcd, u16 typeReq, u16 wValue, u16 wIndex,
+	    char *buf, u16 wLength);
+
+static inline struct tegra_xusb *hcd_to_tegra_xusb(struct usb_hcd *hcd)
+{
+	return (struct tegra_xusb *) dev_get_drvdata(hcd->self.controller);
+}
 
 static inline u32 fpci_readl(struct tegra_xusb *tegra, unsigned int offset)
 {
@@ -1949,12 +1964,27 @@ static void tegra_xhci_enable_phy_sleepwalk_wake(struct tegra_xusb *tegra)
 static void tegra_xhci_disable_phy_wake(struct tegra_xusb *tegra)
 {
 	struct tegra_xusb_padctl *padctl = tegra->padctl;
-	unsigned int i;
+	unsigned int i, j;
 
 	for (i = 0; i < tegra->num_phys; i++) {
 		if (!tegra->phys[i])
 			continue;
+		if (tegra_xusb_padctl_remote_wake_detected(padctl, tegra->phys[i])) {
+			if (i < (tegra->soc->ports.usb3.offset + tegra->soc->ports.usb3.count)) {
+				j = i;
+			} else if (i < (tegra->soc->ports.usb2.offset +
+					tegra->soc->ports.usb2.count)) {
+				j = i - tegra->soc->ports.usb2.offset;
+				tegra_phy_xusb_utmi_pad_power_on(tegra->phys[i]);
+			} else {
+				j = i - (tegra->soc->ports.usb2.offset +
+					 tegra->soc->ports.usb2.count);
+			}
+			dev_dbg(tegra->dev,
+				"%s port %u (0 based) remote wake detected\n",
+				dev_name(&tegra->phys[i]->dev), j);
 
+		}
 		tegra_xusb_padctl_disable_phy_wake(padctl, tegra->phys[i]);
 	}
 }
@@ -1972,6 +2002,22 @@ 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;
+
+	for (i = 0; i < tegra->soc->ports.usb2.count; i++) {
+		if (!is_host_mode_phy(tegra, USB2_PHY, i))
+			continue;
+		if (tegra->enable_utmi_pad_after_lp0_exit & BIT(i))
+			tegra_phy_xusb_utmi_pad_power_on(
+				tegra->phys[tegra->soc->ports.usb2.offset + i]);
+		else
+			tegra_phy_xusb_utmi_pad_power_down(
+				tegra->phys[tegra->soc->ports.usb2.offset + i]);
+	}
+}
+
 static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
 {
 	struct xhci_hcd *xhci = hcd_to_xhci(tegra->hcd);
@@ -1980,6 +2026,7 @@ 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 +2040,15 @@ static int tegra_xusb_enter_elpg(struct tegra_xusb *tegra, bool runtime)
 		goto out;
 	}
 
+	for (i = 0; i < tegra->soc->ports.usb2.count; i++) {
+		if (!xhci->usb2_rhub.ports[i])
+			continue;
+		portsc = readl(xhci->usb2_rhub.ports[i]->addr);
+		tegra->enable_utmi_pad_after_lp0_exit &= ~BIT(i);
+		if (((portsc & PORT_PLS_MASK) == XDEV_U3) || ((portsc & DEV_SPEED_MASK) == XDEV_FS))
+			tegra->enable_utmi_pad_after_lp0_exit |= BIT(i);
+	}
+
 	err = xhci_suspend(xhci, wakeup);
 	if (err < 0) {
 		dev_err(tegra->dev, "failed to suspend XHCI: %d\n", err);
@@ -2066,6 +2122,8 @@ 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);
@@ -2437,6 +2495,74 @@ 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 = hcd_to_tegra_xusb(hcd);
+	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+	struct xhci_hub *rhub;
+	struct xhci_bus_state *bus_state;
+	int port = (index & 0xff) - 1;
+	int port_index;
+	struct xhci_port **ports;
+	u32 portsc;
+	int ret;
+
+	rhub = &xhci->usb2_rhub;
+	bus_state = &rhub->bus_state;
+	if (bus_state->resuming_ports && hcd->speed == HCD_USB2) {
+		ports = rhub->ports;
+		port_index = rhub->num_ports;
+		while (port_index--) {
+			if (!test_bit(port_index, &bus_state->resuming_ports))
+				continue;
+			portsc = readl(ports[port_index]->addr);
+			if ((portsc & PORT_PLS_MASK) == XDEV_RESUME)
+				tegra_phy_xusb_utmi_pad_power_on(
+					tegra->phys[tegra->soc->ports.usb2.offset + port_index]);
+		}
+	}
+
+	if (hcd->speed == HCD_USB2) {
+		port_index = tegra->soc->ports.usb2.offset + port;
+		if ((type_req == ClearPortFeature) && (value == USB_PORT_FEAT_SUSPEND))
+			tegra_phy_xusb_utmi_pad_power_on(tegra->phys[port_index]);
+		if ((type_req == SetPortFeature) && (value == USB_PORT_FEAT_RESET)) {
+			ports = rhub->ports;
+			portsc = readl(ports[port]->addr);
+			if (portsc & PORT_CONNECT)
+				tegra_phy_xusb_utmi_pad_power_on(tegra->phys[port_index]);
+		}
+	}
+
+	ret = (*original_xhci_hub_control)(hcd, type_req, value, index, buf, length);
+	if (ret < 0)
+		return ret;
+
+	if (hcd->speed == HCD_USB2) {
+		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(tegra->phys[port_index]);
+
+		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(tegra->phys[port_index]);
+			}
+		}
+		if ((type_req == SetPortFeature) && (value == USB_PORT_FEAT_TEST))
+			tegra_phy_xusb_utmi_pad_power_on(tegra->phys[port_index]);
+	}
+
+	return ret;
+}
+
 static const struct xhci_driver_overrides tegra_xhci_overrides __initconst = {
 	.reset = tegra_xhci_setup,
 };
@@ -2444,6 +2570,8 @@ static const struct xhci_driver_overrides tegra_xhci_overrides __initconst = {
 static int __init tegra_xusb_init(void)
 {
 	xhci_init_driver(&tegra_xhci_hc_driver, &tegra_xhci_overrides);
+	original_xhci_hub_control = tegra_xhci_hc_driver.hub_control;
+	tegra_xhci_hc_driver.hub_control = tegra_xhci_hub_control;
 
 	return platform_driver_register(&tegra_xusb_driver);
 }
-- 
2.17.1