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authorJonathan Lemon <jonathan.lemon@gmail.com>2021-09-14 19:16:34 -0700
committerDavid S. Miller <davem@davemloft.net>2021-09-15 11:10:01 +0100
commit6d59d4fa1789e0ca51dc33494376272a61b80104 (patch)
tree1bd6ca1ba065ae0414ae55b411c9b9d808982c3c /drivers/ptp
parenta62a56d04e63cf0ececb5dd339811f0a14b7e77c (diff)
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.c40
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,