usb: add usb2 Link PM variables to sysfs and usb_device

Adds abitilty to tune L1 timeout (inactivity timer for usb2 link sleep)
and BESL (best effort service latency)via sysfs.

This also adds a new usb2_lpm_parameters structure with those variables to
struct usb_device.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index fe444989668a..a232b7ece1f6 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -394,6 +394,22 @@ enum usb_port_connect_type {
 };
 
 /*
+ * USB 2.0 Link Power Management (LPM) parameters.
+ */
+struct usb2_lpm_parameters {
+        /* Best effort service latency indicate how long the host will drive
+         * resume on an exit from L1.
+         */
+        unsigned int besl;
+
+        /* Timeout value in microseconds for the L1 inactivity (LPM) timer.
+         * When the timer counts to zero, the parent hub will initiate a LPM
+         * transition to L1.
+         */
+        int timeout;
+};
+
+/*
  * USB 3.0 Link Power Management (LPM) parameters.
  *
  * PEL and SEL are USB 3.0 Link PM latencies for device-initiated LPM exit.
@@ -488,6 +504,7 @@ 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
+ * @l1_params: best effor service latency for USB2 L1 LPM state, and L1 timeout.
  * @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()
@@ -568,6 +585,7 @@ struct usb_device {
         struct wusb_dev *wusb_dev;
         int slot_id;
         enum usb_device_removable removable;
+        struct usb2_lpm_parameters l1_params;
         struct usb3_lpm_parameters u1_params;
         struct usb3_lpm_parameters u2_params;
         unsigned lpm_disable_count;