4 files changed, 75 insertions, 2 deletions
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 22e7b53123ef..40439dfd81a7 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -409,6 +409,12 @@ struct usb3_lpm_parameters {
 	 * it will get data.
 	 */
 	unsigned int sel;
+	/*
+	 * The idle timeout value that is currently programmed into the parent
+	 * hub for this device.  When the timer counts to zero, the parent hub
+	 * will initiate an LPM transition to either U1 or U2.
+	 */
+	int timeout;
 };
 
 /**
@@ -468,8 +474,12 @@ struct usb3_lpm_parameters {
  *	specific data for the device.
  * @slot_id: Slot ID assigned by xHCI
  * @removable: Device can be physically removed from this port
- * @u1_params: exit latencies for U1 (USB 3.0 LPM).
- * @u2_params: exit latencies for U2 (USB 3.0 LPM).
+ * @u1_params: exit latencies for USB3 U1 LPM state, and hub-initiated timeout.
+ * @u2_params: exit latencies for USB3 U2 LPM state, and hub-initiated timeout.
+ * @lpm_disable_count: Ref count used by usb_disable_lpm() and usb_enable_lpm()
+ *	to keep track of the number of functions that require USB 3.0 Link Power
+ *	Management to be disabled for this usb_device.  This count should only
+ *	be manipulated by those functions, with the bandwidth_mutex is held.
  *
  * Notes:
  * Usbcore drivers should not set usbdev->state directly.  Instead use
@@ -544,6 +554,7 @@ struct usb_device {
 	enum usb_device_removable removable;
 	struct usb3_lpm_parameters u1_params;
 	struct usb3_lpm_parameters u2_params;
+	unsigned lpm_disable_count;
 };
 #define	to_usb_device(d) container_of(d, struct usb_device, dev)
 
@@ -579,6 +590,12 @@ extern void usb_autopm_put_interface_async(struct usb_interface *intf);
 extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf);
 extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf);
 
+extern int usb_disable_lpm(struct usb_device *udev);
+extern void usb_enable_lpm(struct usb_device *udev);
+/* Same as above, but these functions lock/unlock the bandwidth_mutex. */
+extern int usb_unlocked_disable_lpm(struct usb_device *udev);
+extern void usb_unlocked_enable_lpm(struct usb_device *udev);
+
 static inline void usb_mark_last_busy(struct usb_device *udev)
 {
 	pm_runtime_mark_last_busy(&udev->dev);
diff --git a/include/linux/usb/ch11.h b/include/linux/usb/ch11.h
index f1d26b6067f1..b6c2863b2c94 100644
--- a/include/linux/usb/ch11.h
+++ b/include/linux/usb/ch11.h
@@ -76,6 +76,8 @@
 #define USB_PORT_FEAT_C_BH_PORT_RESET		29
 #define USB_PORT_FEAT_FORCE_LINKPM_ACCEPT	30
 
+#define USB_PORT_LPM_TIMEOUT(p)			(((p) & 0xff) << 8)
+
 /* USB 3.0 hub remote wake mask bits, see table 10-14 */
 #define USB_PORT_FEAT_REMOTE_WAKE_CONNECT	(1 << 8)
 #define USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT	(1 << 9)
diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h
index e785d85b617f..43bce9da7a4d 100644
--- a/include/linux/usb/ch9.h
+++ b/include/linux/usb/ch9.h
@@ -935,6 +935,51 @@ enum usb_device_state {
 	 */
 };
 
+enum usb3_link_state {
+	USB3_LPM_U0 = 0,
+	USB3_LPM_U1,
+	USB3_LPM_U2,
+	USB3_LPM_U3
+};
+
+/*
+ * A U1 timeout of 0x0 means the parent hub will reject any transitions to U1.
+ * 0xff means the parent hub will accept transitions to U1, but will not
+ * initiate a transition.
+ *
+ * A U1 timeout of 0x1 to 0x7F also causes the hub to initiate a transition to
+ * U1 after that many microseconds.  Timeouts of 0x80 to 0xFE are reserved
+ * values.
+ *
+ * A U2 timeout of 0x0 means the parent hub will reject any transitions to U2.
+ * 0xff means the parent hub will accept transitions to U2, but will not
+ * initiate a transition.
+ *
+ * A U2 timeout of 0x1 to 0xFE also causes the hub to initiate a transition to
+ * U2 after N*256 microseconds.  Therefore a U2 timeout value of 0x1 means a U2
+ * idle timer of 256 microseconds, 0x2 means 512 microseconds, 0xFE means
+ * 65.024ms.
+ */
+#define USB3_LPM_DISABLED		0x0
+#define USB3_LPM_U1_MAX_TIMEOUT		0x7F
+#define USB3_LPM_U2_MAX_TIMEOUT		0xFE
+#define USB3_LPM_DEVICE_INITIATED	0xFF
+
+struct usb_set_sel_req {
+	__u8	u1_sel;
+	__u8	u1_pel;
+	__le16	u2_sel;
+	__le16	u2_pel;
+} __attribute__ ((packed));
+
+/*
+ * The Set System Exit Latency control transfer provides one byte each for
+ * U1 SEL and U1 PEL, so the max exit latency is 0xFF.  U2 SEL and U2 PEL each
+ * are two bytes long.
+ */
+#define USB3_LPM_MAX_U1_SEL_PEL		0xFF
+#define USB3_LPM_MAX_U2_SEL_PEL		0xFFFF
+
 /*-------------------------------------------------------------------------*/
 
 /*
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index bbb946437070..7f855d50cdf5 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -344,6 +344,15 @@ struct hc_driver {
 		 */
 	int	(*update_device)(struct usb_hcd *, struct usb_device *);
 	int	(*set_usb2_hw_lpm)(struct usb_hcd *, struct usb_device *, int);
+	/* USB 3.0 Link Power Management */
+		/* Returns the USB3 hub-encoded value for the U1/U2 timeout. */
+	int	(*enable_usb3_lpm_timeout)(struct usb_hcd *,
+			struct usb_device *, enum usb3_link_state state);
+		/* The xHCI host controller can still fail the command to
+		 * disable the LPM timeouts, so this can return an error code.
+		 */
+	int	(*disable_usb3_lpm_timeout)(struct usb_hcd *,
+			struct usb_device *, enum usb3_link_state state);
 };
 
 extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb);