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path: root/drivers/ieee1394/ieee1394_core.c
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Diffstat (limited to 'drivers/ieee1394/ieee1394_core.c')
-rw-r--r--drivers/ieee1394/ieee1394_core.c43
1 files changed, 43 insertions, 0 deletions
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);