USB: Add a sysfs file to show LTM capabilities.
USB 3.0 devices can optionally support Latency Tolerance Messaging
(LTM). Add a new sysfs file in the device directory to show whether a
device is LTM capable. This file will be present for both USB 2.0 and
USB 3.0 devices.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 777f03c..682e825 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -253,6 +253,15 @@
}
static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);
+static ssize_t
+show_ltm_capable(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ if (usb_device_supports_ltm(to_usb_device(dev)))
+ return sprintf(buf, "%s\n", "yes");
+ return sprintf(buf, "%s\n", "no");
+}
+static DEVICE_ATTR(ltm_capable, S_IRUGO, show_ltm_capable, NULL);
+
#ifdef CONFIG_PM
static ssize_t
@@ -649,6 +658,7 @@
&dev_attr_authorized.attr,
&dev_attr_remove.attr,
&dev_attr_removable.attr,
+ &dev_attr_ltm_capable.attr,
NULL,
};
static struct attribute_group dev_attr_grp = {