The SJA1110 switch integrates TJA1103 PHYs, but in SJA1110 switch rev B
silicon, there is a bug in that the registers for selecting the 100base-T1
autoneg master/slave roles are not writable.
To enable write access to the master/slave registers, these additional
PHY writes are necessary during initialization.
The issue has been corrected in later SJA1110 silicon versions and is
not present in the standalone PHY variants, but applying the workaround
unconditionally in the driver should not do any harm.
Suggested-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The reconstruction procedure for partial timestamps reads the current
PTP time and fills in the low 2 bits of the second portion, as well as
the nanoseconds portion, from the actual hardware packet timestamp.
Critically, the reconstruction procedure works because it assumes that
the current PTP time is strictly larger than the hardware timestamp was:
it detects a 2-bit wraparound of the 'seconds' portion by checking whether
the 'seconds' portion of the partial hardware timestamp is larger than
the 'seconds' portion of the current time. That can only happen if the
hardware timestamp was captured by the PHY during the last phase of a
'modulo 4 seconds' interval, and the current PTP time was read by the
driver during the initial phase of the next 'modulo 4 seconds' interval.
The partial RX timestamps are added to priv->rx_queue in
nxp_c45_rxtstamp() and they are processed potentially in parallel by the
aux worker thread in nxp_c45_do_aux_work(). This means that it is
possible for nxp_c45_do_aux_work() to process more than one RX timestamp
during the same schedule.
There is one premature optimization that will cause issues: for RX
timestamping, the driver reads the current time only once, and it uses
that to reconstruct all PTP RX timestamps in the queue. For the second
and later timestamps, this will be an issue if we are processing two RX
timestamps which are to the left and to the right, respectively, of a
4-bit wraparound of the 'seconds' portion of the PTP time, and the
current PTP time is also pre-wraparound.
0.000000000 4.000000000 8.000000000 12.000000000
|..................|..................|..................|............>
^ ^ ^ ^ time
| | | |
| | | process hwts 1 and hwts 2
| | |
| | hwts 2
| |
| read current PTP time
|
hwts 1
What will happen in that case is that hwts 2 (post-wraparound) will use
a stale current PTP time that is pre-wraparound.
But nxp_c45_reconstruct_ts will not detect this condition, because it is
not coded up for it, so it will reconstruct hwts 2 with a current time
from the previous 4 second interval (i.e. 0.something instead of
4.something).
This is solvable by making sure that the full 64-bit current time is
always read after the PHY has taken the partial RX timestamp. We do this
by reading the current PTP time for every timestamp in the RX queue.
Fixes: 514def5dd3 ("phy: nxp-c45-tja11xx: add timestamping support")
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
nxp_c45_reconstruct_ts() takes a partial hardware timestamp in @hwts,
with 2 bits of the 'seconds' portion, and a full PTP time in @ts.
It patches in the lower bits of @hwts into @ts, and to ensure that the
reconstructed timestamp is correct, it checks whether the lower 2 bits
of @hwts are not in fact higher than the lower 2 bits of @ts. This is
not logically possible because, according to the calling convention, @ts
was collected later in time than @hwts, but due to two's complement
arithmetic it can actually happen, because the current PTP time might
have wrapped around between when @hwts was collected and when @ts was,
yielding the lower 2 bits of @ts smaller than those of @hwts.
To correct for that situation which is expected to happen under normal
conditions, the driver subtracts exactly one wraparound interval from
the reconstructed timestamp, since the upper bits of that need to
correspond to what the upper bits of @hwts were, not to what the upper
bits of @ts were.
Readers might be confused because the driver denotes the amount of bits
that the partial hardware timestamp has to offer as TS_SEC_MASK
(timestamp mask for seconds). But it subtracts a seemingly unrelated
BIT(2), which is in fact more subtle: if the hardware timestamp provides
2 bits of partial 'seconds' timestamp, then the wraparound interval is
2^2 == BIT(2).
But nonetheless, it is better to express the wraparound interval in
terms of a definition we already have, so replace BIT(2) with
1 + GENMASK(1, 0) which produces the same result but is clearer.
Suggested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The SJA1110 switch integrates these PHYs, and they do not have support
for timestamping. This message becomes quite overwhelming:
[ 10.056596] NXP C45 TJA1103 spi1.0-base-t1:01: the phy does not support PTP
[ 10.112625] NXP C45 TJA1103 spi1.0-base-t1:02: the phy does not support PTP
[ 10.167461] NXP C45 TJA1103 spi1.0-base-t1:03: the phy does not support PTP
[ 10.223510] NXP C45 TJA1103 spi1.0-base-t1:04: the phy does not support PTP
[ 10.278239] NXP C45 TJA1103 spi1.0-base-t1:05: the phy does not support PTP
[ 10.332663] NXP C45 TJA1103 spi1.0-base-t1:06: the phy does not support PTP
[ 15.390828] NXP C45 TJA1103 spi1.2-base-t1:01: the phy does not support PTP
[ 15.445224] NXP C45 TJA1103 spi1.2-base-t1:02: the phy does not support PTP
[ 15.499673] NXP C45 TJA1103 spi1.2-base-t1:03: the phy does not support PTP
[ 15.554074] NXP C45 TJA1103 spi1.2-base-t1:04: the phy does not support PTP
[ 15.608516] NXP C45 TJA1103 spi1.2-base-t1:05: the phy does not support PTP
[ 15.662996] NXP C45 TJA1103 spi1.2-base-t1:06: the phy does not support PTP
So reduce its log level to debug.
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add mii_timestamper interface and register a ptp clock.
The package timestamping can work with or without interrupts.
RX timestamps are received in the reserved field of the PTP package.
TX timestamps are read via MDIO from a set of registers.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Added .config_intr and .handle_interrupt callbacks.
Link event interrupt will trigger an interrupt every time when the link
goes up or down.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix phase offset calculation.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add driver for tja1103 driver and for future NXP C45 PHYs.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vladimir Oltean