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path: root/drivers/net/ethernet/intel/igb/igb_ptp.c
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Diffstat (limited to 'drivers/net/ethernet/intel/igb/igb_ptp.c')
-rw-r--r--drivers/net/ethernet/intel/igb/igb_ptp.c385
1 files changed, 385 insertions, 0 deletions
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
new file mode 100644
index 000000000000..d5ee7fa50723
--- /dev/null
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -0,0 +1,385 @@
+/*
+ * PTP Hardware Clock (PHC) driver for the Intel 82576 and 82580
+ *
+ * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+
+#include "igb.h"
+
+#define INCVALUE_MASK 0x7fffffff
+#define ISGN 0x80000000
+
+/*
+ * The 82580 timesync updates the system timer every 8ns by 8ns,
+ * and this update value cannot be reprogrammed.
+ *
+ * Neither the 82576 nor the 82580 offer registers wide enough to hold
+ * nanoseconds time values for very long. For the 82580, SYSTIM always
+ * counts nanoseconds, but the upper 24 bits are not availible. The
+ * frequency is adjusted by changing the 32 bit fractional nanoseconds
+ * register, TIMINCA.
+ *
+ * For the 82576, the SYSTIM register time unit is affect by the
+ * choice of the 24 bit TININCA:IV (incvalue) field. Five bits of this
+ * field are needed to provide the nominal 16 nanosecond period,
+ * leaving 19 bits for fractional nanoseconds.
+ *
+ * We scale the NIC clock cycle by a large factor so that relatively
+ * small clock corrections can be added or subtracted at each clock
+ * tick. The drawbacks of a large factor are a) that the clock
+ * register overflows more quickly (not such a big deal) and b) that
+ * the increment per tick has to fit into 24 bits. As a result we
+ * need to use a shift of 19 so we can fit a value of 16 into the
+ * TIMINCA register.
+ *
+ *
+ * SYSTIMH SYSTIML
+ * +--------------+ +---+---+------+
+ * 82576 | 32 | | 8 | 5 | 19 |
+ * +--------------+ +---+---+------+
+ * \________ 45 bits _______/ fract
+ *
+ * +----------+---+ +--------------+
+ * 82580 | 24 | 8 | | 32 |
+ * +----------+---+ +--------------+
+ * reserved \______ 40 bits _____/
+ *
+ *
+ * The 45 bit 82576 SYSTIM overflows every
+ * 2^45 * 10^-9 / 3600 = 9.77 hours.
+ *
+ * The 40 bit 82580 SYSTIM overflows every
+ * 2^40 * 10^-9 / 60 = 18.3 minutes.
+ */
+
+#define IGB_OVERFLOW_PERIOD (HZ * 60 * 9)
+#define INCPERIOD_82576 (1 << E1000_TIMINCA_16NS_SHIFT)
+#define INCVALUE_82576_MASK ((1 << E1000_TIMINCA_16NS_SHIFT) - 1)
+#define INCVALUE_82576 (16 << IGB_82576_TSYNC_SHIFT)
+#define IGB_NBITS_82580 40
+
+/*
+ * SYSTIM read access for the 82576
+ */
+
+static cycle_t igb_82576_systim_read(const struct cyclecounter *cc)
+{
+ u64 val;
+ u32 lo, hi;
+ struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
+ struct e1000_hw *hw = &igb->hw;
+
+ lo = rd32(E1000_SYSTIML);
+ hi = rd32(E1000_SYSTIMH);
+
+ val = ((u64) hi) << 32;
+ val |= lo;
+
+ return val;
+}
+
+/*
+ * SYSTIM read access for the 82580
+ */
+
+static cycle_t igb_82580_systim_read(const struct cyclecounter *cc)
+{
+ u64 val;
+ u32 lo, hi, jk;
+ struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
+ struct e1000_hw *hw = &igb->hw;
+
+ /*
+ * The timestamp latches on lowest register read. For the 82580
+ * the lowest register is SYSTIMR instead of SYSTIML. However we only
+ * need to provide nanosecond resolution, so we just ignore it.
+ */
+ jk = rd32(E1000_SYSTIMR);
+ lo = rd32(E1000_SYSTIML);
+ hi = rd32(E1000_SYSTIMH);
+
+ val = ((u64) hi) << 32;
+ val |= lo;
+
+ return val;
+}
+
+/*
+ * PTP clock operations
+ */
+
+static int ptp_82576_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+ u64 rate;
+ u32 incvalue;
+ int neg_adj = 0;
+ struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+ struct e1000_hw *hw = &igb->hw;
+
+ if (ppb < 0) {
+ neg_adj = 1;
+ ppb = -ppb;
+ }
+ rate = ppb;
+ rate <<= 14;
+ rate = div_u64(rate, 1953125);
+
+ incvalue = 16 << IGB_82576_TSYNC_SHIFT;
+
+ if (neg_adj)
+ incvalue -= rate;
+ else
+ incvalue += rate;
+
+ wr32(E1000_TIMINCA, INCPERIOD_82576 | (incvalue & INCVALUE_82576_MASK));
+
+ return 0;
+}
+
+static int ptp_82580_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+ u64 rate;
+ u32 inca;
+ int neg_adj = 0;
+ struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+ struct e1000_hw *hw = &igb->hw;
+
+ if (ppb < 0) {
+ neg_adj = 1;
+ ppb = -ppb;
+ }
+ rate = ppb;
+ rate <<= 26;
+ rate = div_u64(rate, 1953125);
+
+ inca = rate & INCVALUE_MASK;
+ if (neg_adj)
+ inca |= ISGN;
+
+ wr32(E1000_TIMINCA, inca);
+
+ return 0;
+}
+
+static int igb_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ s64 now;
+ unsigned long flags;
+ struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+ spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+ now = timecounter_read(&igb->tc);
+ now += delta;
+ timecounter_init(&igb->tc, &igb->cc, now);
+
+ spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+ return 0;
+}
+
+static int igb_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+ u64 ns;
+ u32 remainder;
+ unsigned long flags;
+ struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+ spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+ ns = timecounter_read(&igb->tc);
+
+ spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+ ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
+ ts->tv_nsec = remainder;
+
+ return 0;
+}
+
+static int igb_settime(struct ptp_clock_info *ptp, const struct timespec *ts)
+{
+ u64 ns;
+ unsigned long flags;
+ struct igb_adapter *igb = container_of(ptp, struct igb_adapter, caps);
+
+ ns = ts->tv_sec * 1000000000ULL;
+ ns += ts->tv_nsec;
+
+ spin_lock_irqsave(&igb->tmreg_lock, flags);
+
+ timecounter_init(&igb->tc, &igb->cc, ns);
+
+ spin_unlock_irqrestore(&igb->tmreg_lock, flags);
+
+ return 0;
+}
+
+static int ptp_82576_enable(struct ptp_clock_info *ptp,
+ struct ptp_clock_request *rq, int on)
+{
+ return -EOPNOTSUPP;
+}
+
+static int ptp_82580_enable(struct ptp_clock_info *ptp,
+ struct ptp_clock_request *rq, int on)
+{
+ return -EOPNOTSUPP;
+}
+
+static void igb_overflow_check(struct work_struct *work)
+{
+ struct timespec ts;
+ struct igb_adapter *igb =
+ container_of(work, struct igb_adapter, overflow_work.work);
+
+ igb_gettime(&igb->caps, &ts);
+
+ pr_debug("igb overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
+
+ schedule_delayed_work(&igb->overflow_work, IGB_OVERFLOW_PERIOD);
+}
+
+void igb_ptp_init(struct igb_adapter *adapter)
+{
+ struct e1000_hw *hw = &adapter->hw;
+
+ switch (hw->mac.type) {
+ case e1000_i210:
+ case e1000_i211:
+ case e1000_i350:
+ case e1000_82580:
+ adapter->caps.owner = THIS_MODULE;
+ strcpy(adapter->caps.name, "igb-82580");
+ adapter->caps.max_adj = 62499999;
+ adapter->caps.n_ext_ts = 0;
+ adapter->caps.pps = 0;
+ adapter->caps.adjfreq = ptp_82580_adjfreq;
+ adapter->caps.adjtime = igb_adjtime;
+ adapter->caps.gettime = igb_gettime;
+ adapter->caps.settime = igb_settime;
+ adapter->caps.enable = ptp_82580_enable;
+ adapter->cc.read = igb_82580_systim_read;
+ adapter->cc.mask = CLOCKSOURCE_MASK(IGB_NBITS_82580);
+ adapter->cc.mult = 1;
+ adapter->cc.shift = 0;
+ /* Enable the timer functions by clearing bit 31. */
+ wr32(E1000_TSAUXC, 0x0);
+ break;
+
+ case e1000_82576:
+ adapter->caps.owner = THIS_MODULE;
+ strcpy(adapter->caps.name, "igb-82576");
+ adapter->caps.max_adj = 1000000000;
+ adapter->caps.n_ext_ts = 0;
+ adapter->caps.pps = 0;
+ adapter->caps.adjfreq = ptp_82576_adjfreq;
+ adapter->caps.adjtime = igb_adjtime;
+ adapter->caps.gettime = igb_gettime;
+ adapter->caps.settime = igb_settime;
+ adapter->caps.enable = ptp_82576_enable;
+ adapter->cc.read = igb_82576_systim_read;
+ adapter->cc.mask = CLOCKSOURCE_MASK(64);
+ adapter->cc.mult = 1;
+ adapter->cc.shift = IGB_82576_TSYNC_SHIFT;
+ /* Dial the nominal frequency. */
+ wr32(E1000_TIMINCA, INCPERIOD_82576 | INCVALUE_82576);
+ break;
+
+ default:
+ adapter->ptp_clock = NULL;
+ return;
+ }
+
+ wrfl();
+
+ timecounter_init(&adapter->tc, &adapter->cc,
+ ktime_to_ns(ktime_get_real()));
+
+ INIT_DELAYED_WORK(&adapter->overflow_work, igb_overflow_check);
+
+ spin_lock_init(&adapter->tmreg_lock);
+
+ schedule_delayed_work(&adapter->overflow_work, IGB_OVERFLOW_PERIOD);
+
+ adapter->ptp_clock = ptp_clock_register(&adapter->caps);
+ if (IS_ERR(adapter->ptp_clock)) {
+ adapter->ptp_clock = NULL;
+ dev_err(&adapter->pdev->dev, "ptp_clock_register failed\n");
+ } else
+ dev_info(&adapter->pdev->dev, "added PHC on %s\n",
+ adapter->netdev->name);
+}
+
+void igb_ptp_remove(struct igb_adapter *adapter)
+{
+ cancel_delayed_work_sync(&adapter->overflow_work);
+
+ if (adapter->ptp_clock) {
+ ptp_clock_unregister(adapter->ptp_clock);
+ dev_info(&adapter->pdev->dev, "removed PHC on %s\n",
+ adapter->netdev->name);
+ }
+}
+
+/**
+ * igb_systim_to_hwtstamp - convert system time value to hw timestamp
+ * @adapter: board private structure
+ * @hwtstamps: timestamp structure to update
+ * @systim: unsigned 64bit system time value.
+ *
+ * We need to convert the system time value stored in the RX/TXSTMP registers
+ * into a hwtstamp which can be used by the upper level timestamping functions.
+ *
+ * The 'tmreg_lock' spinlock is used to protect the consistency of the
+ * system time value. This is needed because reading the 64 bit time
+ * value involves reading two (or three) 32 bit registers. The first
+ * read latches the value. Ditto for writing.
+ *
+ * In addition, here have extended the system time with an overflow
+ * counter in software.
+ **/
+void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
+ struct skb_shared_hwtstamps *hwtstamps,
+ u64 systim)
+{
+ u64 ns;
+ unsigned long flags;
+
+ switch (adapter->hw.mac.type) {
+ case e1000_i210:
+ case e1000_i211:
+ case e1000_i350:
+ case e1000_82580:
+ case e1000_82576:
+ break;
+ default:
+ return;
+ }
+
+ spin_lock_irqsave(&adapter->tmreg_lock, flags);
+
+ ns = timecounter_cyc2time(&adapter->tc, systim);
+
+ spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+
+ memset(hwtstamps, 0, sizeof(*hwtstamps));
+ hwtstamps->hwtstamp = ns_to_ktime(ns);
+}