diff options
| author |  Stefan Richter
| 2012-06-18 01:19:54 +0200 |
|---|---|---|
| committer | Stefan Richter
| 2012-06-18 01:53:32 +0200 |
| commit | 5b4cffe9d7b515d807874da48c6a149edc37a99b (patch) | |
| tree | 07aa5bc3df3617e8caeaae59ba2f68fa35e0619e /src/fw-iso.c | |
| parent | Tweak raw1394_add_config_rom_descriptor() API, add documentation and test case (diff) | |
Add raw1394_read_cycle_timer_and_clock() API
This is an extension relative to raw1394_read_cycle_timer().
It lets the client choose a system clock other than CLOCK_REALTIME.
Use case: http://subversion.ffado.org/ticket/242
The underlying ioctl supports reading the system clock with nanoseconds
resolution. The new libraw1394 call sticks with microseconds resolution
though. This makes transition from (or parallel use with)
raw1394_read_cycle_timer() easier. Besides, the call itself takes longer
than a microsecond, primarily due to a costly MMIO read (on many
controllers even three or more MMIO reads).
Unit tests with CLOCK_MONOTONIC and CLOCK_MONOTONIC_RAW are added to
testlibraw as well.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'src/fw-iso.c')
| -rw-r--r-- | src/fw-iso.c | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/src/fw-iso.c b/src/fw-iso.c index 15fa233..9599299 100644 --- a/src/fw-iso.c +++ b/src/fw-iso.c @@ -648,8 +648,8 @@ void fw_iso_shutdown(fw_handle_t handle) handle->iso.fd = -1; } -int fw_read_cycle_timer(fw_handle_t handle, - u_int32_t *cycle_timer, u_int64_t *local_time) +int fw_read_cycle_timer(fw_handle_t handle, u_int32_t *cycle_timer, + u_int64_t *local_time) { int err; struct fw_cdev_get_cycle_timer ctr = { 0 }; @@ -661,3 +661,18 @@ int fw_read_cycle_timer(fw_handle_t handle, } return err; } + +int fw_read_cycle_timer_and_clock(fw_handle_t handle, u_int32_t *cycle_timer, + u_int64_t *local_time, clockid_t clk_id) +{ + int err; + struct fw_cdev_get_cycle_timer2 ctr = {.clk_id = clk_id}; + + err = ioctl(handle->ioctl_fd, FW_CDEV_IOC_GET_CYCLE_TIMER2, &ctr); + if (!err) { + *cycle_timer = ctr.cycle_timer; + *local_time = ctr.tv_sec * 1000000ULL + + ctr.tv_nsec / 1000; + } + return err; +} |