net: dsa: sja1105: Restore PTP time after switch reset

The PTP time of the switch is not preserved when uploading a new static
configuration. Work around this hardware oddity by reading its PTP time
before a static config upload, and restoring it afterwards.

Static config changes are expected to occur at runtime even in scenarios
directly related to PTP, i.e. the Time-Aware Scheduler of the switch is
programmed in this way.

Perhaps the larger implication of this patch is that the PTP .gettimex64
and .settime functions need to be exposed to sja1105_main.c, where the
PTP lock needs to be held during this entire process. So their core
implementation needs to move to some common functions which get exposed
in sja1105_ptp.h.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 21 insertions, 3 deletions

diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.h b/drivers/net/dsa/sja1105/sja1105_ptp.h
index 243f130374d2..19e707db7e8c 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.h
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.h
@@ -51,8 +51,6 @@ int sja1105_get_ts_info(struct dsa_switch *ds, int port,
 void sja1105_ptp_txtstamp_skb(struct dsa_switch *ds, int slot,
 			      struct sk_buff *clone);
 
-int sja1105_ptp_reset(struct dsa_switch *ds);
-
 bool sja1105_port_rxtstamp(struct dsa_switch *ds, int port,
 			   struct sk_buff *skb, unsigned int type);
 
@@ -63,6 +61,14 @@ int sja1105_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr);
 
 int sja1105_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr);
 
+int __sja1105_ptp_gettimex(struct dsa_switch *ds, u64 *ns,
+			   struct ptp_system_timestamp *sts);
+
+int __sja1105_ptp_settime(struct dsa_switch *ds, u64 ns,
+			  struct ptp_system_timestamp *ptp_sts);
+
+int __sja1105_ptp_adjtime(struct dsa_switch *ds, s64 delta);
+
 #else
 
 struct sja1105_ptp_cmd;
@@ -87,7 +93,19 @@ static inline void sja1105_ptp_txtstamp_skb(struct dsa_switch *ds, int slot,
 {
 }
 
-static inline int sja1105_ptp_reset(struct dsa_switch *ds)
+static inline int __sja1105_ptp_gettimex(struct dsa_switch *ds, u64 *ns,
+					 struct ptp_system_timestamp *sts)
+{
+	return 0;
+}
+
+static inline int __sja1105_ptp_settime(struct dsa_switch *ds, u64 ns,
+					struct ptp_system_timestamp *ptp_sts)
+{
+	return 0;
+}
+
+static inline int __sja1105_ptp_adjtime(struct dsa_switch *ds, s64 delta)
 {
 	return 0;
 }