1 files changed, 381 insertions, 0 deletions
diff --git a/drivers/net/dsa/mv88e6xxx/ptp.c b/drivers/net/dsa/mv88e6xxx/ptp.c
new file mode 100644
index 000000000000..bd85e2c390e1
--- /dev/null
+++ b/drivers/net/dsa/mv88e6xxx/ptp.c
@@ -0,0 +1,381 @@
+/*
+ * 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 dw_overflow_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
+					     overflow_work)
+#define dw_tai_event_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
+					      tai_event_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 int mv88e6xxx_tai_write(struct mv88e6xxx_chip *chip, int addr, u16 data)
+{
+	if (!chip->info->ops->avb_ops->tai_write)
+		return -EOPNOTSUPP;
+
+	return chip->info->ops->avb_ops->tai_write(chip, addr, data);
+}
+
+/* TODO: places where this are called should be using pinctrl */
+static int mv88e6xxx_set_gpio_func(struct mv88e6xxx_chip *chip, int pin,
+				   int func, int input)
+{
+	int err;
+
+	if (!chip->info->ops->gpio_ops)
+		return -EOPNOTSUPP;
+
+	err = chip->info->ops->gpio_ops->set_dir(chip, pin, input);
+	if (err)
+		return err;
+
+	return chip->info->ops->gpio_ops->set_pctl(chip, pin, func);
+}
+
+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];
+}
+
+/* mv88e6xxx_config_eventcap - configure TAI event capture
+ * @event: PTP_CLOCK_PPS (internal) or PTP_CLOCK_EXTTS (external)
+ * @rising: zero for falling-edge trigger, else rising-edge trigger
+ *
+ * This will also reset the capture sequence counter.
+ */
+static int mv88e6xxx_config_eventcap(struct mv88e6xxx_chip *chip, int event,
+				     int rising)
+{
+	u16 global_config;
+	u16 cap_config;
+	int err;
+
+	chip->evcap_config = MV88E6XXX_TAI_CFG_CAP_OVERWRITE |
+			     MV88E6XXX_TAI_CFG_CAP_CTR_START;
+	if (!rising)
+		chip->evcap_config |= MV88E6XXX_TAI_CFG_EVREQ_FALLING;
+
+	global_config = (chip->evcap_config | chip->trig_config);
+	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_CFG, global_config);
+	if (err)
+		return err;
+
+	if (event == PTP_CLOCK_PPS) {
+		cap_config = MV88E6XXX_TAI_EVENT_STATUS_CAP_TRIG;
+	} else if (event == PTP_CLOCK_EXTTS) {
+		/* if STATUS_CAP_TRIG is unset we capture PTP_EVREQ events */
+		cap_config = 0;
+	} else {
+		return -EINVAL;
+	}
+
+	/* Write the capture config; this also clears the capture counter */
+	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS,
+				  cap_config);
+
+	return err;
+}
+
+static void mv88e6xxx_tai_event_work(struct work_struct *ugly)
+{
+	struct delayed_work *dw = to_delayed_work(ugly);
+	struct mv88e6xxx_chip *chip = dw_tai_event_to_chip(dw);
+	struct ptp_clock_event ev;
+	u16 status[4];
+	u32 raw_ts;
+	int err;
+
+	mutex_lock(&chip->reg_lock);
+	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_EVENT_STATUS,
+				 status, ARRAY_SIZE(status));
+	mutex_unlock(&chip->reg_lock);
+
+	if (err) {
+		dev_err(chip->dev, "failed to read TAI status register\n");
+		return;
+	}
+	if (status[0] & MV88E6XXX_TAI_EVENT_STATUS_ERROR) {
+		dev_warn(chip->dev, "missed event capture\n");
+		return;
+	}
+	if (!(status[0] & MV88E6XXX_TAI_EVENT_STATUS_VALID))
+		goto out;
+
+	raw_ts = ((u32)status[2] << 16) | status[1];
+
+	/* Clear the valid bit so the next timestamp can come in */
+	status[0] &= ~MV88E6XXX_TAI_EVENT_STATUS_VALID;
+	mutex_lock(&chip->reg_lock);
+	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS, status[0]);
+	mutex_unlock(&chip->reg_lock);
+
+	/* This is an external timestamp */
+	ev.type = PTP_CLOCK_EXTTS;
+
+	/* We only have one timestamping channel. */
+	ev.index = 0;
+	mutex_lock(&chip->reg_lock);
+	ev.timestamp = timecounter_cyc2time(&chip->tstamp_tc, raw_ts);
+	mutex_unlock(&chip->reg_lock);
+
+	ptp_clock_event(chip->ptp_clock, &ev);
+out:
+	schedule_delayed_work(&chip->tai_event_work, TAI_EVENT_WORK_INTERVAL);
+}
+
+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_extts(struct mv88e6xxx_chip *chip,
+				      struct ptp_clock_request *rq, int on)
+{
+	int rising = (rq->extts.flags & PTP_RISING_EDGE);
+	int func;
+	int pin;
+	int err;
+
+	pin = ptp_find_pin(chip->ptp_clock, PTP_PF_EXTTS, rq->extts.index);
+
+	if (pin < 0)
+		return -EBUSY;
+
+	mutex_lock(&chip->reg_lock);
+
+	if (on) {
+		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_EVREQ;
+
+		err = mv88e6xxx_set_gpio_func(chip, pin, func, true);
+		if (err)
+			goto out;
+
+		schedule_delayed_work(&chip->tai_event_work,
+				      TAI_EVENT_WORK_INTERVAL);
+
+		err = mv88e6xxx_config_eventcap(chip, PTP_CLOCK_EXTTS, rising);
+	} else {
+		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_GPIO;
+
+		err = mv88e6xxx_set_gpio_func(chip, pin, func, true);
+
+		cancel_delayed_work_sync(&chip->tai_event_work);
+	}
+
+out:
+	mutex_unlock(&chip->reg_lock);
+
+	return err;
+}
+
+static int mv88e6xxx_ptp_enable(struct ptp_clock_info *ptp,
+				struct ptp_clock_request *rq, int on)
+{
+	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
+
+	switch (rq->type) {
+	case PTP_CLK_REQ_EXTTS:
+		return mv88e6xxx_ptp_enable_extts(chip, rq, on);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int mv88e6xxx_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
+				enum ptp_pin_function func, unsigned int chan)
+{
+	switch (func) {
+	case PTP_PF_NONE:
+	case PTP_PF_EXTTS:
+		break;
+	case PTP_PF_PEROUT:
+	case PTP_PF_PHYSYNC:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+/* 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)
+{
+	int i;
+
+	/* 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);
+	INIT_DELAYED_WORK(&chip->tai_event_work, mv88e6xxx_tai_event_work);
+
+	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.n_ext_ts	= 1;
+	chip->ptp_clock_info.n_per_out	= 0;
+	chip->ptp_clock_info.n_pins	= mv88e6xxx_num_gpio(chip);
+	chip->ptp_clock_info.pps	= 0;
+
+	for (i = 0; i < chip->ptp_clock_info.n_pins; ++i) {
+		struct ptp_pin_desc *ppd = &chip->pin_config[i];
+
+		snprintf(ppd->name, sizeof(ppd->name), "mv88e6xxx_gpio%d", i);
+		ppd->index = i;
+		ppd->func = PTP_PF_NONE;
+	}
+	chip->ptp_clock_info.pin_config = chip->pin_config;
+
+	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_info.do_aux_work = mv88e6xxx_hwtstamp_work;
+
+	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);
+		cancel_delayed_work_sync(&chip->tai_event_work);
+
+		ptp_clock_unregister(chip->ptp_clock);
+		chip->ptp_clock = NULL;
+	}
+}