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/*
* 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)
{
switch (adapter->hw.mac.type) {
case e1000_i211:
case e1000_i210:
case e1000_i350:
case e1000_82580:
case e1000_82576:
cancel_delayed_work_sync(&adapter->overflow_work);
break;
default:
return;
}
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);
}