diff options
| author | Jonathan Lemon <jonathan.lemon@gmail.com> | 2021-09-15 04:16:34 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-09-15 12:10:01 +0200 |
| commit | 6d59d4fa1789e0ca51dc33494376272a61b80104 (patch) | |
| tree | 1bd6ca1ba065ae0414ae55b411c9b9d808982c3c /drivers/ptp | |
| parent | ptp: ocp: Enable 4th timestamper / PPS generator (diff) | |
| download | linux-6d59d4fa1789e0ca51dc33494376272a61b80104.tar.xz linux-6d59d4fa1789e0ca51dc33494376272a61b80104.zip | |
ptp: ocp: Have FPGA fold in ns adjustment for adjtime.
The current implementation of adjtime uses gettime/settime to
perform nanosecond adjustments. This introduces addtional phase
errors due to delays.
Instead, use the FPGA's ability to just apply the nanosecond
adjustment to the clock directly.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/ptp')
| -rw-r--r-- | drivers/ptp/ptp_ocp.c | 40 |
1 files changed, 25 insertions, 15 deletions
diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c index be8ab727a4ef..e6779a712bbb 100644 --- a/drivers/ptp/ptp_ocp.c +++ b/drivers/ptp/ptp_ocp.c @@ -594,9 +594,6 @@ ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts) struct ptp_ocp *bp = container_of(ptp_info, struct ptp_ocp, ptp_info); unsigned long flags; - if (ioread32(&bp->reg->status) & OCP_STATUS_IN_SYNC) - return 0; - spin_lock_irqsave(&bp->lock, flags); __ptp_ocp_settime_locked(bp, ts); spin_unlock_irqrestore(&bp->lock, flags); @@ -604,26 +601,39 @@ ptp_ocp_settime(struct ptp_clock_info *ptp_info, const struct timespec64 *ts) return 0; } +static void +__ptp_ocp_adjtime_locked(struct ptp_ocp *bp, u64 adj_val) +{ + u32 select, ctrl; + + select = ioread32(&bp->reg->select); + iowrite32(OCP_SELECT_CLK_REG, &bp->reg->select); + + iowrite32(adj_val, &bp->reg->offset_ns); + iowrite32(adj_val & 0x7f, &bp->reg->offset_window_ns); + + ctrl = OCP_CTRL_ADJUST_OFFSET | OCP_CTRL_ENABLE; + iowrite32(ctrl, &bp->reg->ctrl); + + /* restore clock selection */ + iowrite32(select >> 16, &bp->reg->select); +} + static int ptp_ocp_adjtime(struct ptp_clock_info *ptp_info, s64 delta_ns) { struct ptp_ocp *bp = container_of(ptp_info, struct ptp_ocp, ptp_info); - struct timespec64 ts; unsigned long flags; - int err; + u32 adj_ns, sign; - if (ioread32(&bp->reg->status) & OCP_STATUS_IN_SYNC) - return 0; + sign = delta_ns < 0 ? BIT(31) : 0; + adj_ns = sign ? -delta_ns : delta_ns; spin_lock_irqsave(&bp->lock, flags); - err = __ptp_ocp_gettime_locked(bp, &ts, NULL); - if (likely(!err)) { - timespec64_add_ns(&ts, delta_ns); - __ptp_ocp_settime_locked(bp, &ts); - } + __ptp_ocp_adjtime_locked(bp, sign | adj_ns); spin_unlock_irqrestore(&bp->lock, flags); - return err; + return 0; } static int @@ -636,7 +646,7 @@ ptp_ocp_null_adjfine(struct ptp_clock_info *ptp_info, long scaled_ppm) } static int -ptp_ocp_adjphase(struct ptp_clock_info *ptp_info, s32 phase_ns) +ptp_ocp_null_adjphase(struct ptp_clock_info *ptp_info, s32 phase_ns) { return -EOPNOTSUPP; } @@ -699,7 +709,7 @@ static const struct ptp_clock_info ptp_ocp_clock_info = { .settime64 = ptp_ocp_settime, .adjtime = ptp_ocp_adjtime, .adjfine = ptp_ocp_null_adjfine, - .adjphase = ptp_ocp_adjphase, + .adjphase = ptp_ocp_null_adjphase, .enable = ptp_ocp_enable, .pps = true, .n_ext_ts = 4, |