[PATCH] USB: Add usbfs ioctl to get the frame number

From: Danny Budik <[email protected]>

This patch (as899) adds a new ioctl to usbfs: USBDEVFS_GETFRAMENUM.
It allows user programs to obtain the current Start-Of-Frame number on
a USB bus.

Note that the values returned by the get_frame method in the various
host controller drivers are not consistent.  They should be adjusted
so that they provide the actual frame number as it appears on the bus;
that is, a number incrementing by one every millisecond, ranging from 0
to 2047.  That will have to be done separately; it interacts with the
start_frame values used for submitting Isochronous URBs.

Signed-off-by: Alan Stern <[email protected]>

---

Index: usb-2.6/drivers/usb/core/devio.c
===================================================================
--- usb-2.6.orig/drivers/usb/core/devio.c
+++ usb-2.6/drivers/usb/core/devio.c
@@ -831,6 +831,18 @@ static int proc_getdriver(struct dev_sta
 	return ret;
 }
 
+static int proc_getframenum(struct dev_state *ps, void __user *arg)
+{
+	int frame_number;
+
+	frame_number = usb_get_current_frame_number(ps->dev);
+	if (frame_number < 0)
+		return frame_number;
+	if (put_user(frame_number, (int __user *)arg))
+		return -EFAULT;
+	return 0;
+}
+
 static int proc_connectinfo(struct dev_state *ps, void __user *arg)
 {
 	struct usbdevfs_connectinfo ci;
@@ -1567,6 +1579,12 @@ static int usbdev_ioctl(struct inode *in
 		snoop(&dev->dev, "%s: IOCTL\n", __FUNCTION__);
 		ret = proc_ioctl_default(ps, p);
 		break;
+
+	case USBDEVFS_GETFRAMENUM:
+		snoop(&dev->dev, "%s: GETFRAMENUM\n", __FUNCTION__);
+		ret = proc_getframenum(ps, p);
+		break;
+
 	}
 	usb_unlock_device(dev);
 	if (ret >= 0)
Index: usb-2.6/include/linux/usbdevice_fs.h
===================================================================
--- usb-2.6.orig/include/linux/usbdevice_fs.h
+++ usb-2.6/include/linux/usbdevice_fs.h
@@ -173,4 +173,5 @@ struct usbdevfs_ioctl32 {
 #define USBDEVFS_CLEAR_HALT        _IOR('U', 21, unsigned int)
 #define USBDEVFS_DISCONNECT        _IO('U', 22)
 #define USBDEVFS_CONNECT           _IO('U', 23)
+#define USBDEVFS_GETFRAMENUM       _IOW('U', 24, int)
 #endif /* _LINUX_USBDEVICE_FS_H */


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