5 files changed, 78 insertions, 0 deletions

diff --git a/drivers/ieee1394/ieee1394-ioctl.h b/drivers/ieee1394/ieee1394-ioctl.h
index 8f207508ed1d..46878fef136c 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 1521e57e124b..d791d08c743c 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 536ba3f580fd..bd29d8ef5bbd 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 a77a832828c8..5d08d7450f96 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 35bfc38f013c..7bd22ee1afbb 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 */