Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=3dc5ea9b31a8c83cffa338aba91adbc9bd387002
Commit:     3dc5ea9b31a8c83cffa338aba91adbc9bd387002
Parent:     91efa462054d44ae52b0c6c8325ed5e899f2cd17
Author:     Pieter Palmers <[EMAIL PROTECTED]>
AuthorDate: Sat Feb 3 17:44:39 2007 +0100
Committer:  Stefan Richter <[EMAIL PROTECTED]>
CommitDate: Sat Feb 17 14:39:33 2007 +0100

    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 <[EMAIL PROTECTED]>
    Acked-by: Pieter Palmers <[EMAIL PROTECTED]>
    Acked-by: Dan Dennedy <[EMAIL PROTECTED]>
---
 drivers/ieee1394/ieee1394-ioctl.h |    2 +
 drivers/ieee1394/ieee1394_core.c  |   43 +++++++++++++++++++++++++++++++++++++
 drivers/ieee1394/ieee1394_core.h  |    3 ++
 drivers/ieee1394/raw1394.c        |   20 +++++++++++++++++
 drivers/ieee1394/raw1394.h        |   10 ++++++++
 5 files changed, 78 insertions(+), 0 deletions(-)

diff --git a/drivers/ieee1394/ieee1394-ioctl.h 
b/drivers/ieee1394/ieee1394-ioctl.h
index 8f20750..46878fe 100644
--- a/drivers/ieee1394/ieee1394-ioctl.h
+++ b/drivers/ieee1394/ieee1394-ioctl.h
@@ -100,5 +100,7 @@
        _IO  ('#', 0x28)
 #define RAW1394_IOC_ISO_RECV_FLUSH             \
        _IO  ('#', 0x29)
+#define RAW1394_IOC_GET_CYCLE_TIMER            \
+       _IOR ('#', 0x30, struct raw1394_cycle_timer)
 
 #endif /* __IEEE1394_IOCTL_H */
diff --git a/drivers/ieee1394/ieee1394_core.c b/drivers/ieee1394/ieee1394_core.c
index 1521e57..d791d08 100644
--- a/drivers/ieee1394/ieee1394_core.c
+++ b/drivers/ieee1394/ieee1394_core.c
@@ -33,7 +33,10 @@
 #include <linux/skbuff.h>
 #include <linux/suspend.h>
 #include <linux/kthread.h>
+#include <linux/preempt.h>
+#include <linux/time.h>
 
+#include <asm/system.h>
 #include <asm/byteorder.h>
 
 #include "ieee1394_types.h"
@@ -186,6 +189,45 @@ int hpsb_reset_bus(struct hpsb_host *host, int type)
        }
 }
 
+/**
+ * hpsb_read_cycle_timer - read cycle timer register and system time
+ * @host: host whose isochronous cycle timer register is read
+ * @cycle_timer: address of bitfield to return the register contents
+ * @local_time: address to return the system time
+ *
+ * The format of * @cycle_timer, is described in OHCI 1.1 clause 5.13. This
+ * format is also read from non-OHCI controllers. * @local_time contains the
+ * system time in microseconds since the Epoch, read at the moment when the
+ * cycle timer was read.
+ *
+ * Return value: 0 for success or error number otherwise.
+ */
+int hpsb_read_cycle_timer(struct hpsb_host *host, u32 *cycle_timer,
+                         u64 *local_time)
+{
+       int ctr;
+       struct timeval tv;
+       unsigned long flags;
+
+       if (!host || !cycle_timer || !local_time)
+               return -EINVAL;
+
+       preempt_disable();
+       local_irq_save(flags);
+
+       ctr = host->driver->devctl(host, GET_CYCLE_COUNTER, 0);
+       if (ctr)
+               do_gettimeofday(&tv);
+
+       local_irq_restore(flags);
+       preempt_enable();
+
+       if (!ctr)
+               return -EIO;
+       *cycle_timer = ctr;
+       *local_time = tv.tv_sec * 1000000ULL + tv.tv_usec;
+       return 0;
+}
 
 int hpsb_bus_reset(struct hpsb_host *host)
 {
@@ -1190,6 +1232,7 @@ EXPORT_SYMBOL(hpsb_alloc_packet);
 EXPORT_SYMBOL(hpsb_free_packet);
 EXPORT_SYMBOL(hpsb_send_packet);
 EXPORT_SYMBOL(hpsb_reset_bus);
+EXPORT_SYMBOL(hpsb_read_cycle_timer);
 EXPORT_SYMBOL(hpsb_bus_reset);
 EXPORT_SYMBOL(hpsb_selfid_received);
 EXPORT_SYMBOL(hpsb_selfid_complete);
diff --git a/drivers/ieee1394/ieee1394_core.h b/drivers/ieee1394/ieee1394_core.h
index 536ba3f..bd29d8e 100644
--- a/drivers/ieee1394/ieee1394_core.h
+++ b/drivers/ieee1394/ieee1394_core.h
@@ -127,6 +127,9 @@ int hpsb_send_packet_and_wait(struct hpsb_packet *packet);
  * progress, 0 otherwise. */
 int hpsb_reset_bus(struct hpsb_host *host, int type);
 
+int hpsb_read_cycle_timer(struct hpsb_host *host, u32 *cycle_timer,
+                         u64 *local_time);
+
 /*
  * The following functions are exported for host driver module usage.  All of
  * them are safe to use in interrupt contexts, although some are quite
diff --git a/drivers/ieee1394/raw1394.c b/drivers/ieee1394/raw1394.c
index a77a832..5d08d74 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;
 }
 
diff --git a/drivers/ieee1394/raw1394.h b/drivers/ieee1394/raw1394.h
index 35bfc38..7bd22ee 100644
--- a/drivers/ieee1394/raw1394.h
+++ b/drivers/ieee1394/raw1394.h
@@ -178,4 +178,14 @@ struct raw1394_iso_status {
        __s16 xmit_cycle;
 };
 
+/* argument to RAW1394_IOC_GET_CYCLE_TIMER ioctl */
+struct raw1394_cycle_timer {
+       /* contents of Isochronous Cycle Timer register,
+          as in OHCI 1.1 clause 5.13 (also with non-OHCI hosts) */
+       __u32 cycle_timer;
+
+       /* local time in microseconds since Epoch,
+          simultaneously read with cycle timer */
+       __u64 local_time;
+};
 #endif /* IEEE1394_RAW1394_H */
-
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