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authorPieter Palmers <pieterp@joow.be>2007-02-03 17:44:39 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2007-02-17 14:39:33 +0100
commit3dc5ea9b31a8c83cffa338aba91adbc9bd387002 (patch)
tree5a9d9682d77fb3a1cfd3dc27654301f69ababf12 /drivers/ieee1394/raw1394.c
parent91efa462054d44ae52b0c6c8325ed5e899f2cd17 (diff)
ieee1394: cycle timer read extension for raw1394
This implements the simultaneous read of the isochronous cycle timer and the system clock (in usecs). This allows to express the exact receive time of an ISO packet as a system time with microsecond accuracy. http://bugzilla.kernel.org/show_bug.cgi?id=7773 The counterpart patch for libraw1394 can be found at http://thread.gmane.org/gmane.linux.kernel.firewire.devel/8934 Patch update (Stefan R.): Disable preemption and local interrupts. Prevent integer overflow. Add paranoid error checks and kerneldoc to hpsb_read_cycle_timer. Move it to other ieee1394_core high-level API functions. Change comments. Adjust whitespace. Rename struct _raw1394_cycle_timer. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Acked-by: Pieter Palmers <pieterp@joow.be> Acked-by: Dan Dennedy <dan@dennedy.org>
Diffstat (limited to 'drivers/ieee1394/raw1394.c')
-rw-r--r--drivers/ieee1394/raw1394.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c
index a77a832828c..5d08d7450f9 100644
--- a/drivers/ieee1394/raw1394.c
+++ b/drivers/ieee1394/raw1394.c
@@ -2669,6 +2669,18 @@ static void raw1394_iso_shutdown(struct file_info *fi)
fi->iso_state = RAW1394_ISO_INACTIVE;
}
+static int raw1394_read_cycle_timer(struct file_info *fi, void __user * uaddr)
+{
+ struct raw1394_cycle_timer ct;
+ int err;
+
+ err = hpsb_read_cycle_timer(fi->host, &ct.cycle_timer, &ct.local_time);
+ if (!err)
+ if (copy_to_user(uaddr, &ct, sizeof(ct)))
+ err = -EFAULT;
+ return err;
+}
+
/* mmap the rawiso xmit/recv buffer */
static int raw1394_mmap(struct file *file, struct vm_area_struct *vma)
{
@@ -2777,6 +2789,14 @@ static int raw1394_ioctl(struct inode *inode, struct file *file,
break;
}
+ /* state-independent commands */
+ switch(cmd) {
+ case RAW1394_IOC_GET_CYCLE_TIMER:
+ return raw1394_read_cycle_timer(fi, argp);
+ default:
+ break;
+ }
+
return -EINVAL;
}