diff options
Diffstat (limited to 'drivers/ieee1394/ieee1394_core.c')
| -rw-r--r-- | drivers/ieee1394/ieee1394_core.c | 43 |
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); |