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, 54 insertions, 0 deletions

diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index aa38db44818a..d9284b998bd7 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -497,8 +497,62 @@ set_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR(usb2_hardware_lpm, S_IRUGO | S_IWUSR, show_usb2_hardware_lpm,
                         set_usb2_hardware_lpm);
 
+static ssize_t
+show_usb2_lpm_l1_timeout(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct usb_device *udev = to_usb_device(dev);
+        return sprintf(buf, "%d\n", udev->l1_params.timeout);
+}
+
+static ssize_t
+set_usb2_lpm_l1_timeout(struct device *dev, struct device_attribute *attr,
+                        const char *buf, size_t count)
+{
+        struct usb_device *udev = to_usb_device(dev);
+        u16 timeout;
+
+        if (kstrtou16(buf, 0, &timeout))
+                return -EINVAL;
+
+        udev->l1_params.timeout = timeout;
+
+        return count;
+}
+
+static DEVICE_ATTR(usb2_lpm_l1_timeout, S_IRUGO | S_IWUSR,
+                   show_usb2_lpm_l1_timeout, set_usb2_lpm_l1_timeout);
+
+static ssize_t
+show_usb2_lpm_besl(struct device *dev, struct device_attribute *attr,
+                   char *buf)
+{
+        struct usb_device *udev = to_usb_device(dev);
+        return sprintf(buf, "%d\n", udev->l1_params.besl);
+}
+
+static ssize_t
+set_usb2_lpm_besl(struct device *dev, struct device_attribute *attr,
+                const char *buf, size_t count)
+{
+        struct usb_device *udev = to_usb_device(dev);
+        u8 besl;
+
+        if (kstrtou8(buf, 0, &besl) || besl > 15)
+                return -EINVAL;
+
+        udev->l1_params.besl = besl;
+
+        return count;
+}
+
+static DEVICE_ATTR(usb2_lpm_besl, S_IRUGO | S_IWUSR,
+                   show_usb2_lpm_besl, set_usb2_lpm_besl);
+
 static struct attribute *usb2_hardware_lpm_attr[] = {
         &dev_attr_usb2_hardware_lpm.attr,
+        &dev_attr_usb2_lpm_l1_timeout.attr,
+        &dev_attr_usb2_lpm_besl.attr,
         NULL,
 };
 static struct attribute_group usb2_hardware_lpm_attr_group = {