/*
* Marvell 88E6xxx Switch PTP support
*
* Copyright (c) 2008 Marvell Semiconductor
*
* Copyright (c) 2017 National Instruments
* Erik Hons <erik.hons@ni.com>
* Brandon Streiff <brandon.streiff@ni.com>
* Dane Wagner <dane.wagner@ni.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.
*/
#include "chip.h"
#include "global2.h"
#include "ptp.h"
/* Raw timestamps are in units of 8-ns clock periods. */
#define CC_SHIFT 28
#define CC_MULT (8 << CC_SHIFT)
#define CC_MULT_NUM (1 << 9)
#define CC_MULT_DEM 15625ULL
#define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100)
#define cc_to_chip(cc) container_of(cc, struct mv88e6xxx_chip, tstamp_cc)
#define ptp_to_chip(ptp) container_of(ptp, struct mv88e6xxx_chip, \
ptp_clock_info)
#define dw_overflow_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
overflow_work)
static int mv88e6xxx_tai_read(struct mv88e6xxx_chip *chip, int addr,
u16 *data, int len)
{
if (!chip->info->ops->avb_ops->tai_read)
return -EOPNOTSUPP;
return chip->info->ops->avb_ops->tai_read(chip, addr, data, len);
}
static u64 mv88e6xxx_ptp_clock_read(const struct cyclecounter *cc)
{
struct mv88e6xxx_chip *chip = cc_to_chip(cc);
u16 phc_time[2];
int err;
err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_TIME_LO, phc_time,
ARRAY_SIZE(phc_time));
if (err)
return 0;
else
return ((u32)phc_time[1] << 16) | phc_time[0];
}
static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
int neg_adj = 0;
u32 diff, mult;
u64 adj;
if (scaled_ppm < 0) {
neg_adj = 1;
scaled_ppm = -scaled_ppm;
}
mult = CC_MULT;
adj = CC_MULT_NUM;
adj *= scaled_ppm;
diff = div_u64(adj, CC_MULT_DEM);
mutex_lock(&chip->reg_lock);
timecounter_read(&chip->tstamp_tc);
chip->tstamp_cc.mult = neg_adj ? mult - diff : mult + diff;
mutex_unlock(&chip->reg_lock);
return 0;
}
static int mv88e6xxx_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
mutex_lock(&chip->reg_lock);
timecounter_adjtime(&chip->tstamp_tc, delta);
mutex_unlock(&chip->reg_lock);
return 0;
}
static int mv88e6xxx_ptp_gettime(struct ptp_clock_info *ptp,
struct timespec64 *ts)
{
struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
u64 ns;
mutex_lock(&chip->reg_lock);
ns = timecounter_read(&chip->tstamp_tc);
mutex_unlock(&chip->reg_lock);
*ts = ns_to_timespec64(ns);
return 0;
}
static int mv88e6xxx_ptp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
u64 ns;
ns = timespec64_to_ns(ts);
mutex_lock(&chip->reg_lock);
timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc, ns);
mutex_unlock(&chip->reg_lock);
return 0;
}
static int mv88e6xxx_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
return -EOPNOTSUPP;
}
static int mv88e6xxx_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
enum ptp_pin_function func, unsigned int chan)
{
return -EOPNOTSUPP;
}
/* With a 125MHz input clock, the 32-bit timestamp counter overflows in ~34.3
* seconds; this task forces periodic reads so that we don't miss any.
*/
#define MV88E6XXX_TAI_OVERFLOW_PERIOD (HZ * 16)
static void mv88e6xxx_ptp_overflow_check(struct work_struct *work)
{
struct delayed_work *dw = to_delayed_work(work);
struct mv88e6xxx_chip *chip = dw_overflow_to_chip(dw);
struct timespec64 ts;
mv88e6xxx_ptp_gettime(&chip->ptp_clock_info, &ts);
schedule_delayed_work(&chip->overflow_work,
MV88E6XXX_TAI_OVERFLOW_PERIOD);
}
int mv88e6xxx_ptp_setup(struct mv88e6xxx_chip *chip)
{
/* Set up the cycle counter */
memset(&chip->tstamp_cc, 0, sizeof(chip->tstamp_cc));
chip->tstamp_cc.read = mv88e6xxx_ptp_clock_read;
chip->tstamp_cc.mask = CYCLECOUNTER_MASK(32);
chip->tstamp_cc.mult = CC_MULT;
chip->tstamp_cc.shift = CC_SHIFT;
timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc,
ktime_to_ns(ktime_get_real()));
INIT_DELAYED_WORK(&chip->overflow_work, mv88e6xxx_ptp_overflow_check);
chip->ptp_clock_info.owner = THIS_MODULE;
snprintf(chip->ptp_clock_info.name, sizeof(chip->ptp_clock_info.name),
dev_name(chip->dev));
chip->ptp_clock_info.max_adj = 1000000;
chip->ptp_clock_info.adjfine = mv88e6xxx_ptp_adjfine;
chip->ptp_clock_info.adjtime = mv88e6xxx_ptp_adjtime;
chip->ptp_clock_info.gettime64 = mv88e6xxx_ptp_gettime;
chip->ptp_clock_info.settime64 = mv88e6xxx_ptp_settime;
chip->ptp_clock_info.enable = mv88e6xxx_ptp_enable;
chip->ptp_clock_info.verify = mv88e6xxx_ptp_verify;
chip->ptp_clock = ptp_clock_register(&chip->ptp_clock_info, chip->dev);
if (IS_ERR(chip->ptp_clock))
return PTR_ERR(chip->ptp_clock);
schedule_delayed_work(&chip->overflow_work,
MV88E6XXX_TAI_OVERFLOW_PERIOD);
return 0;
}
void mv88e6xxx_ptp_free(struct mv88e6xxx_chip *chip)
{
if (chip->ptp_clock) {
cancel_delayed_work_sync(&chip->overflow_work);
ptp_clock_unregister(chip->ptp_clock);
chip->ptp_clock = NULL;
}
}
