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authorAlan Stern <stern@rowland.harvard.edu>2007-02-20 15:03:32 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2007-02-23 15:03:47 -0800
commit19c262391c4741b012a5031fc438fb694e77c385 (patch)
tree1ce81bf30086104f8102b83617d31d998338fbd6 /drivers/usb/core/sysfs.c
parentdfa87c824a9a5430008acd1ed2e8111ed164fcbe (diff)
USB: export autosuspend delay in sysfs
This patch (as861) adds sysfs attributes to expose the autosuspend delay value for each USB device. If the user changes the delay from 0 (no autosuspend) to a positive value, an autosuspend is attempted. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core/sysfs.c')
-rw-r--r--drivers/usb/core/sysfs.c64
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index cad4fb323f6..311d5df8038 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -158,6 +158,65 @@ show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
}
static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);
+#ifdef CONFIG_USB_SUSPEND
+
+static ssize_t
+show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct usb_device *udev = to_usb_device(dev);
+
+ return sprintf(buf, "%u\n", udev->autosuspend_delay / HZ);
+}
+
+static ssize_t
+set_autosuspend(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct usb_device *udev = to_usb_device(dev);
+ unsigned value, old;
+
+ if (sscanf(buf, "%u", &value) != 1 || value >= INT_MAX/HZ)
+ return -EINVAL;
+ value *= HZ;
+
+ old = udev->autosuspend_delay;
+ udev->autosuspend_delay = value;
+ if (value > 0 && old == 0)
+ usb_try_autosuspend_device(udev);
+
+ return count;
+}
+
+static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
+ show_autosuspend, set_autosuspend);
+
+static char power_group[] = "power";
+
+static int add_power_attributes(struct device *dev)
+{
+ int rc = 0;
+
+ if (is_usb_device(dev))
+ rc = sysfs_add_file_to_group(&dev->kobj,
+ &dev_attr_autosuspend.attr,
+ power_group);
+ return rc;
+}
+
+static void remove_power_attributes(struct device *dev)
+{
+ sysfs_remove_file_from_group(&dev->kobj,
+ &dev_attr_autosuspend.attr,
+ power_group);
+}
+
+#else
+
+#define add_power_attributes(dev) 0
+#define remove_power_attributes(dev) do {} while (0)
+
+#endif /* CONFIG_USB_SUSPEND */
+
/* Descriptor fields */
#define usb_descriptor_attr_le16(field, format_string) \
static ssize_t \
@@ -230,6 +289,10 @@ int usb_create_sysfs_dev_files(struct usb_device *udev)
if (retval)
return retval;
+ retval = add_power_attributes(dev);
+ if (retval)
+ goto error;
+
if (udev->manufacturer) {
retval = device_create_file(dev, &dev_attr_manufacturer);
if (retval)
@@ -262,6 +325,7 @@ void usb_remove_sysfs_dev_files(struct usb_device *udev)
device_remove_file(dev, &dev_attr_manufacturer);
device_remove_file(dev, &dev_attr_product);
device_remove_file(dev, &dev_attr_serial);
+ remove_power_attributes(dev);
sysfs_remove_group(&dev->kobj, &dev_attr_grp);
}