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-rw-r--r--drivers/firewire/fw-cdev.c26
-rw-r--r--include/linux/firewire-cdev.h15
2 files changed, 41 insertions, 0 deletions
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index b960fd996918..290d9f036199 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -25,11 +25,14 @@
#include <linux/device.h>
#include <linux/vmalloc.h>
#include <linux/poll.h>
+#include <linux/preempt.h>
+#include <linux/time.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/idr.h>
#include <linux/compat.h>
#include <linux/firewire-cdev.h>
+#include <asm/system.h>
#include <asm/uaccess.h>
#include "fw-transaction.h"
#include "fw-topology.h"
@@ -811,6 +814,28 @@ static int ioctl_stop_iso(struct client *client, void *buffer)
return fw_iso_context_stop(client->iso_context);
}
+static int ioctl_get_cycle_timer(struct client *client, void *buffer)
+{
+ struct fw_cdev_get_cycle_timer *request = buffer;
+ struct fw_card *card = client->device->card;
+ unsigned long long bus_time;
+ struct timeval tv;
+ unsigned long flags;
+
+ preempt_disable();
+ local_irq_save(flags);
+
+ bus_time = card->driver->get_bus_time(card);
+ do_gettimeofday(&tv);
+
+ local_irq_restore(flags);
+ preempt_enable();
+
+ request->local_time = tv.tv_sec * 1000000ULL + tv.tv_usec;
+ request->cycle_timer = bus_time & 0xffffffff;
+ return 0;
+}
+
static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
ioctl_get_info,
ioctl_send_request,
@@ -824,6 +849,7 @@ static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
ioctl_queue_iso,
ioctl_start_iso,
ioctl_stop_iso,
+ ioctl_get_cycle_timer,
};
static int
diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 1a45d6f41b09..0f0e271f97fa 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -178,6 +178,7 @@ union fw_cdev_event {
#define FW_CDEV_IOC_QUEUE_ISO _IOWR('#', 0x09, struct fw_cdev_queue_iso)
#define FW_CDEV_IOC_START_ISO _IOW('#', 0x0a, struct fw_cdev_start_iso)
#define FW_CDEV_IOC_STOP_ISO _IOW('#', 0x0b, struct fw_cdev_stop_iso)
+#define FW_CDEV_IOC_GET_CYCLE_TIMER _IOR('#', 0x0c, struct fw_cdev_get_cycle_timer)
/* FW_CDEV_VERSION History
*
@@ -459,4 +460,18 @@ struct fw_cdev_stop_iso {
__u32 handle;
};
+/**
+ * struct fw_cdev_get_cycle_timer - read cycle timer register
+ * @local_time: system time, in microseconds since the Epoch
+ * @cycle_timer: isochronous cycle timer, as per OHCI 1.1 clause 5.13
+ *
+ * The %FW_CDEV_IOC_GET_CYCLE_TIMER ioctl reads the isochronous cycle timer
+ * and also the system clock. This allows to express the receive time of an
+ * isochronous packet as a system time with microsecond accuracy.
+ */
+struct fw_cdev_get_cycle_timer {
+ __u64 local_time;
+ __u32 cycle_timer;
+};
+
#endif /* _LINUX_FIREWIRE_CDEV_H */