// SPDX-License-Identifier: GPL-2.0
//
// Copyright (C) 2018 Integrated Device Technology, Inc
//

#define pr_fmt(fmt) "IDT_82p33xxx: " fmt

#include <linux/firmware.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/timekeeping.h>
#include <linux/bitops.h>
#include <linux/of.h>
#include <linux/mfd/rsmu.h>
#include <linux/mfd/idt82p33_reg.h>

#include "ptp_private.h"
#include "ptp_idt82p33.h"

MODULE_DESCRIPTION("Driver for IDT 82p33xxx clock devices");
MODULE_AUTHOR("IDT support-1588 <IDT-support-1588@lm.renesas.com>");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(FW_FILENAME);

#define EXTTS_PERIOD_MS (95)

/* Module Parameters */
static u32 phase_snap_threshold = SNAP_THRESHOLD_NS;
module_param(phase_snap_threshold, uint, 0);
MODULE_PARM_DESC(phase_snap_threshold,
"threshold (10000ns by default) below which adjtime would use double dco");

static char *firmware;
module_param(firmware, charp, 0);

static struct ptp_pin_desc pin_config[MAX_PHC_PLL][MAX_TRIG_CLK];

static inline int idt82p33_read(struct idt82p33 *idt82p33, u16 regaddr,
				u8 *buf, u16 count)
{
	return regmap_bulk_read(idt82p33->regmap, regaddr, buf, count);
}

static inline int idt82p33_write(struct idt82p33 *idt82p33, u16 regaddr,
				 u8 *buf, u16 count)
{
	return regmap_bulk_write(idt82p33->regmap, regaddr, buf, count);
}

static void idt82p33_byte_array_to_timespec(struct timespec64 *ts,
					    u8 buf[TOD_BYTE_COUNT])
{
	time64_t sec;
	s32 nsec;
	u8 i;

	nsec = buf[3];
	for (i = 0; i < 3; i++) {
		nsec <<= 8;
		nsec |= buf[2 - i];
	}

	sec = buf[9];
	for (i = 0; i < 5; i++) {
		sec <<= 8;
		sec |= buf[8 - i];
	}

	ts->tv_sec = sec;
	ts->tv_nsec = nsec;
}

static void idt82p33_timespec_to_byte_array(struct timespec64 const *ts,
					    u8 buf[TOD_BYTE_COUNT])
{
	time64_t sec;
	s32 nsec;
	u8 i;

	nsec = ts->tv_nsec;
	sec = ts->tv_sec;

	for (i = 0; i < 4; i++) {
		buf[i] = nsec & 0xff;
		nsec >>= 8;
	}

	for (i = 4; i < TOD_BYTE_COUNT; i++) {
		buf[i] = sec & 0xff;
		sec >>= 8;
	}
}

static int idt82p33_dpll_set_mode(struct idt82p33_channel *channel,
				  enum pll_mode mode)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 dpll_mode;
	int err;

	if (channel->pll_mode == mode)
		return 0;

	err = idt82p33_read(idt82p33, channel->dpll_mode_cnfg,
			    &dpll_mode, sizeof(dpll_mode));
	if (err)
		return err;

	dpll_mode &= ~(PLL_MODE_MASK << PLL_MODE_SHIFT);

	dpll_mode |= (mode << PLL_MODE_SHIFT);

	err = idt82p33_write(idt82p33, channel->dpll_mode_cnfg,
			     &dpll_mode, sizeof(dpll_mode));
	if (err)
		return err;

	channel->pll_mode = mode;

	return 0;
}

static int idt82p33_set_tod_trigger(struct idt82p33_channel *channel,
				    u8 trigger, bool write)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;
	u8 cfg;

	if (trigger > WR_TRIG_SEL_MAX)
		return -EINVAL;

	err = idt82p33_read(idt82p33, channel->dpll_tod_trigger,
			    &cfg, sizeof(cfg));

	if (err)
		return err;

	if (write == true)
		trigger = (trigger << WRITE_TRIGGER_SHIFT) |
			  (cfg & READ_TRIGGER_MASK);
	else
		trigger = (trigger << READ_TRIGGER_SHIFT) |
			  (cfg & WRITE_TRIGGER_MASK);

	return idt82p33_write(idt82p33, channel->dpll_tod_trigger,
			      &trigger, sizeof(trigger));
}

static int idt82p33_get_extts(struct idt82p33_channel *channel,
			      struct timespec64 *ts)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 buf[TOD_BYTE_COUNT];
	int err;

	err = idt82p33_read(idt82p33, channel->dpll_tod_sts, buf, sizeof(buf));

	if (err)
		return err;

	/* Since trigger is not self clearing itself, we have to poll tod_sts */
	if (memcmp(buf, channel->extts_tod_sts, TOD_BYTE_COUNT) == 0)
		return -EAGAIN;

	memcpy(channel->extts_tod_sts, buf, TOD_BYTE_COUNT);

	idt82p33_byte_array_to_timespec(ts, buf);

	if (channel->discard_next_extts) {
		channel->discard_next_extts = false;
		return -EAGAIN;
	}

	return 0;
}

static int map_ref_to_tod_trig_sel(int ref, u8 *trigger)
{
	int err = 0;

	switch (ref) {
	case 0:
		*trigger = HW_TOD_TRIG_SEL_IN12;
		break;
	case 1:
		*trigger = HW_TOD_TRIG_SEL_IN13;
		break;
	case 2:
		*trigger = HW_TOD_TRIG_SEL_IN14;
		break;
	default:
		err = -EINVAL;
	}

	return err;
}

static bool is_one_shot(u8 mask)
{
	/* Treat single bit PLL masks as continuous trigger */
	if ((mask == 1) || (mask == 2))
		return false;
	else
		return true;
}

static int arm_tod_read_with_trigger(struct idt82p33_channel *channel, u8 trigger)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 buf[TOD_BYTE_COUNT];
	int err;

	/* Remember the current tod_sts before setting the trigger */
	err = idt82p33_read(idt82p33, channel->dpll_tod_sts, buf, sizeof(buf));

	if (err)
		return err;

	memcpy(channel->extts_tod_sts, buf, TOD_BYTE_COUNT);

	err = idt82p33_set_tod_trigger(channel, trigger, false);

	if (err)
		dev_err(idt82p33->dev, "%s: err = %d", __func__, err);

	return err;
}

static int idt82p33_extts_enable(struct idt82p33_channel *channel,
				 struct ptp_clock_request *rq, int on)
{
	u8 index = rq->extts.index;
	struct idt82p33 *idt82p33;
	u8 mask = 1 << index;
	int err = 0;
	u8 old_mask;
	u8 trigger;
	int ref;

	idt82p33  = channel->idt82p33;
	old_mask = idt82p33->extts_mask;

	if (index >= MAX_PHC_PLL)
		return -EINVAL;

	if (on) {
		/* Return if it was already enabled */
		if (idt82p33->extts_mask & mask)
			return 0;

		/* Use the pin configured for the channel */
		ref = ptp_find_pin(channel->ptp_clock, PTP_PF_EXTTS, channel->plln);

		if (ref < 0) {
			dev_err(idt82p33->dev, "%s: No valid pin found for Pll%d!\n",
				__func__, channel->plln);
			return -EBUSY;
		}

		err = map_ref_to_tod_trig_sel(ref, &trigger);

		if (err) {
			dev_err(idt82p33->dev,
				"%s: Unsupported ref %d!\n", __func__, ref);
			return err;
		}

		err = arm_tod_read_with_trigger(&idt82p33->channel[index], trigger);

		if (err == 0) {
			idt82p33->extts_mask |= mask;
			idt82p33->channel[index].tod_trigger = trigger;
			idt82p33->event_channel[index] = channel;
			idt82p33->extts_single_shot = is_one_shot(idt82p33->extts_mask);

			if (old_mask)
				return 0;

			schedule_delayed_work(&idt82p33->extts_work,
					      msecs_to_jiffies(EXTTS_PERIOD_MS));
		}
	} else {
		idt82p33->extts_mask &= ~mask;
		idt82p33->extts_single_shot = is_one_shot(idt82p33->extts_mask);

		if (idt82p33->extts_mask == 0)
			cancel_delayed_work(&idt82p33->extts_work);
	}

	return err;
}

static int idt82p33_extts_check_channel(struct idt82p33 *idt82p33, u8 todn)
{
	struct idt82p33_channel *event_channel;
	struct ptp_clock_event event;
	struct timespec64 ts;
	int err;

	err = idt82p33_get_extts(&idt82p33->channel[todn], &ts);
	if (err == 0) {
		event_channel = idt82p33->event_channel[todn];
		event.type = PTP_CLOCK_EXTTS;
		event.index = todn;
		event.timestamp = timespec64_to_ns(&ts);
		ptp_clock_event(event_channel->ptp_clock,
				&event);
	}
	return err;
}

static u8 idt82p33_extts_enable_mask(struct idt82p33_channel *channel,
				     u8 extts_mask, bool enable)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 trigger = channel->tod_trigger;
	u8 mask;
	int err;
	int i;

	if (extts_mask == 0)
		return 0;

	if (enable == false)
		cancel_delayed_work_sync(&idt82p33->extts_work);

	for (i = 0; i < MAX_PHC_PLL; i++) {
		mask = 1 << i;

		if ((extts_mask & mask) == 0)
			continue;

		if (enable) {
			err = arm_tod_read_with_trigger(&idt82p33->channel[i], trigger);
			if (err)
				dev_err(idt82p33->dev,
					"%s: Arm ToD read trigger failed, err = %d",
					__func__, err);
		} else {
			err = idt82p33_extts_check_channel(idt82p33, i);
			if (err == 0 && idt82p33->extts_single_shot)
				/* trigger happened so we won't re-enable it */
				extts_mask &= ~mask;
		}
	}

	if (enable)
		schedule_delayed_work(&idt82p33->extts_work,
				      msecs_to_jiffies(EXTTS_PERIOD_MS));

	return extts_mask;
}

static int _idt82p33_gettime(struct idt82p33_channel *channel,
			     struct timespec64 *ts)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 old_mask = idt82p33->extts_mask;
	u8 buf[TOD_BYTE_COUNT];
	u8 new_mask = 0;
	int err;

	/* Disable extts */
	if (old_mask)
		new_mask = idt82p33_extts_enable_mask(channel, old_mask, false);

	err = idt82p33_set_tod_trigger(channel, HW_TOD_RD_TRIG_SEL_LSB_TOD_STS,
				       false);
	if (err)
		return err;

	channel->discard_next_extts = true;

	if (idt82p33->calculate_overhead_flag)
		idt82p33->start_time = ktime_get_raw();

	err = idt82p33_read(idt82p33, channel->dpll_tod_sts, buf, sizeof(buf));

	if (err)
		return err;

	/* Re-enable extts */
	if (new_mask)
		idt82p33_extts_enable_mask(channel, new_mask, true);

	idt82p33_byte_array_to_timespec(ts, buf);

	return 0;
}

/*
 *   TOD Trigger:
 *   Bits[7:4] Write 0x9, MSB write
 *   Bits[3:0] Read 0x9, LSB read
 */

static int _idt82p33_settime(struct idt82p33_channel *channel,
			     struct timespec64 const *ts)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	struct timespec64 local_ts = *ts;
	char buf[TOD_BYTE_COUNT];
	s64 dynamic_overhead_ns;
	int err;
	u8 i;

	err = idt82p33_set_tod_trigger(channel, HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
				       true);
	if (err)
		return err;

	channel->discard_next_extts = true;

	if (idt82p33->calculate_overhead_flag) {
		dynamic_overhead_ns = ktime_to_ns(ktime_get_raw())
					- ktime_to_ns(idt82p33->start_time);

		timespec64_add_ns(&local_ts, dynamic_overhead_ns);

		idt82p33->calculate_overhead_flag = 0;
	}

	idt82p33_timespec_to_byte_array(&local_ts, buf);

	/*
	 * Store the new time value.
	 */
	for (i = 0; i < TOD_BYTE_COUNT; i++) {
		err = idt82p33_write(idt82p33, channel->dpll_tod_cnfg + i,
				     &buf[i], sizeof(buf[i]));
		if (err)
			return err;
	}

	return err;
}

static int _idt82p33_adjtime_immediate(struct idt82p33_channel *channel,
				       s64 delta_ns)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	struct timespec64 ts;
	s64 now_ns;
	int err;

	idt82p33->calculate_overhead_flag = 1;

	err = _idt82p33_gettime(channel, &ts);

	if (err)
		return err;

	now_ns = timespec64_to_ns(&ts);
	now_ns += delta_ns + idt82p33->tod_write_overhead_ns;

	ts = ns_to_timespec64(now_ns);

	err = _idt82p33_settime(channel, &ts);

	return err;
}

static int _idt82p33_adjtime_internal_triggered(struct idt82p33_channel *channel,
						s64 delta_ns)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	char buf[TOD_BYTE_COUNT];
	struct timespec64 ts;
	const u8 delay_ns = 32;
	s32 remainder;
	s64 ns;
	int err;

	err = _idt82p33_gettime(channel, &ts);

	if (err)
		return err;

	if (ts.tv_nsec > (NSEC_PER_SEC - 5 * NSEC_PER_MSEC)) {
		/*  Too close to miss next trigger, so skip it */
		mdelay(6);
		ns = (ts.tv_sec + 2) * NSEC_PER_SEC + delta_ns + delay_ns;
	} else
		ns = (ts.tv_sec + 1) * NSEC_PER_SEC + delta_ns + delay_ns;

	ts = ns_to_timespec64(ns);
	idt82p33_timespec_to_byte_array(&ts, buf);

	/*
	 * Store the new time value.
	 */
	err = idt82p33_write(idt82p33, channel->dpll_tod_cnfg, buf, sizeof(buf));
	if (err)
		return err;

	/* Schedule to implement the workaround in one second */
	(void)div_s64_rem(delta_ns, NSEC_PER_SEC, &remainder);
	if (remainder != 0)
		schedule_delayed_work(&channel->adjtime_work, HZ);

	return idt82p33_set_tod_trigger(channel, HW_TOD_TRIG_SEL_TOD_PPS, true);
}

static void idt82p33_adjtime_workaround(struct work_struct *work)
{
	struct idt82p33_channel *channel = container_of(work,
							struct idt82p33_channel,
							adjtime_work.work);
	struct idt82p33 *idt82p33 = channel->idt82p33;

	mutex_lock(idt82p33->lock);
	/* Workaround for TOD-to-output alignment issue */
	_idt82p33_adjtime_internal_triggered(channel, 0);
	mutex_unlock(idt82p33->lock);
}

static int _idt82p33_adjfine(struct idt82p33_channel *channel, long scaled_ppm)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	unsigned char buf[5] = {0};
	int err, i;
	s64 fcw;

	/*
	 * Frequency Control Word unit is: 1.6861512 * 10^-10 ppm
	 *
	 * adjfreq:
	 *       ppb * 10^14
	 * FCW = -----------
	 *         16861512
	 *
	 * adjfine:
	 *       scaled_ppm * 5^12 * 10^5
	 * FCW = ------------------------
	 *            16861512 * 2^4
	 */

	fcw = scaled_ppm * 762939453125ULL;
	fcw = div_s64(fcw, 8430756LL);

	for (i = 0; i < 5; i++) {
		buf[i] = fcw & 0xff;
		fcw >>= 8;
	}

	err = idt82p33_dpll_set_mode(channel, PLL_MODE_DCO);

	if (err)
		return err;

	err = idt82p33_write(idt82p33, channel->dpll_freq_cnfg,
			     buf, sizeof(buf));

	return err;
}

/* ppb = scaled_ppm * 125 / 2^13 */
static s32 idt82p33_ddco_scaled_ppm(long current_ppm, s32 ddco_ppb)
{
	s64 scaled_ppm = div_s64(((s64)ddco_ppb << 13), 125);
	s64 max_scaled_ppm = div_s64(((s64)DCO_MAX_PPB << 13), 125);

	current_ppm += scaled_ppm;

	if (current_ppm > max_scaled_ppm)
		current_ppm = max_scaled_ppm;
	else if (current_ppm < -max_scaled_ppm)
		current_ppm = -max_scaled_ppm;

	return (s32)current_ppm;
}

static int idt82p33_stop_ddco(struct idt82p33_channel *channel)
{
	int err;

	err = _idt82p33_adjfine(channel, channel->current_freq);
	if (err)
		return err;

	channel->ddco = false;

	return 0;
}

static int idt82p33_start_ddco(struct idt82p33_channel *channel, s32 delta_ns)
{
	s32 current_ppm = channel->current_freq;
	u32 duration_ms = MSEC_PER_SEC;
	s32 ppb;
	int err;

	/* If the ToD correction is less than 5 nanoseconds, then skip it.
	 * The error introduced by the ToD adjustment procedure would be bigger
	 * than the required ToD correction
	 */
	if (abs(delta_ns) < DDCO_THRESHOLD_NS)
		return 0;

	/* For most cases, keep ddco duration 1 second */
	ppb = delta_ns;
	while (abs(ppb) > DCO_MAX_PPB) {
		duration_ms *= 2;
		ppb /= 2;
	}

	err = _idt82p33_adjfine(channel,
				idt82p33_ddco_scaled_ppm(current_ppm, ppb));
	if (err)
		return err;

	/* schedule the worker to cancel ddco */
	ptp_schedule_worker(channel->ptp_clock,
			    msecs_to_jiffies(duration_ms) - 1);
	channel->ddco = true;

	return 0;
}

static int idt82p33_measure_one_byte_write_overhead(
		struct idt82p33_channel *channel, s64 *overhead_ns)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	ktime_t start, stop;
	u8 trigger = 0;
	s64 total_ns;
	int err;
	u8 i;

	total_ns = 0;
	*overhead_ns = 0;

	for (i = 0; i < MAX_MEASURMENT_COUNT; i++) {

		start = ktime_get_raw();

		err = idt82p33_write(idt82p33, channel->dpll_tod_trigger,
				     &trigger, sizeof(trigger));

		stop = ktime_get_raw();

		if (err)
			return err;

		total_ns += ktime_to_ns(stop) - ktime_to_ns(start);
	}

	*overhead_ns = div_s64(total_ns, MAX_MEASURMENT_COUNT);

	return err;
}

static int idt82p33_measure_one_byte_read_overhead(
		struct idt82p33_channel *channel, s64 *overhead_ns)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	ktime_t start, stop;
	u8 trigger = 0;
	s64 total_ns;
	int err;
	u8 i;

	total_ns = 0;
	*overhead_ns = 0;

	for (i = 0; i < MAX_MEASURMENT_COUNT; i++) {

		start = ktime_get_raw();

		err = idt82p33_read(idt82p33, channel->dpll_tod_trigger,
				    &trigger, sizeof(trigger));

		stop = ktime_get_raw();

		if (err)
			return err;

		total_ns += ktime_to_ns(stop) - ktime_to_ns(start);
	}

	*overhead_ns = div_s64(total_ns, MAX_MEASURMENT_COUNT);

	return err;
}

static int idt82p33_measure_tod_write_9_byte_overhead(
		struct idt82p33_channel *channel)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 buf[TOD_BYTE_COUNT];
	ktime_t start, stop;
	s64 total_ns;
	int err = 0;
	u8 i, j;

	total_ns = 0;
	idt82p33->tod_write_overhead_ns = 0;

	for (i = 0; i < MAX_MEASURMENT_COUNT; i++) {

		start = ktime_get_raw();

		/* Need one less byte for applicable overhead */
		for (j = 0; j < (TOD_BYTE_COUNT - 1); j++) {
			err = idt82p33_write(idt82p33,
					     channel->dpll_tod_cnfg + i,
					     &buf[i], sizeof(buf[i]));
			if (err)
				return err;
		}

		stop = ktime_get_raw();

		total_ns += ktime_to_ns(stop) - ktime_to_ns(start);
	}

	idt82p33->tod_write_overhead_ns = div_s64(total_ns,
						  MAX_MEASURMENT_COUNT);

	return err;
}

static int idt82p33_measure_settime_gettime_gap_overhead(
		struct idt82p33_channel *channel, s64 *overhead_ns)
{
	struct timespec64 ts1 = {0, 0};
	struct timespec64 ts2;
	int err;

	*overhead_ns = 0;

	err = _idt82p33_settime(channel, &ts1);

	if (err)
		return err;

	err = _idt82p33_gettime(channel, &ts2);

	if (!err)
		*overhead_ns = timespec64_to_ns(&ts2) - timespec64_to_ns(&ts1);

	return err;
}

static int idt82p33_measure_tod_write_overhead(struct idt82p33_channel *channel)
{
	s64 trailing_overhead_ns, one_byte_write_ns, gap_ns, one_byte_read_ns;
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;

	idt82p33->tod_write_overhead_ns = 0;

	err = idt82p33_measure_settime_gettime_gap_overhead(channel, &gap_ns);

	if (err) {
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
		return err;
	}

	err = idt82p33_measure_one_byte_write_overhead(channel,
						       &one_byte_write_ns);

	if (err)
		return err;

	err = idt82p33_measure_one_byte_read_overhead(channel,
						      &one_byte_read_ns);

	if (err)
		return err;

	err = idt82p33_measure_tod_write_9_byte_overhead(channel);

	if (err)
		return err;

	trailing_overhead_ns = gap_ns - 2 * one_byte_write_ns
			       - one_byte_read_ns;

	idt82p33->tod_write_overhead_ns -= trailing_overhead_ns;

	return err;
}

static int idt82p33_check_and_set_masks(struct idt82p33 *idt82p33,
					u8 page,
					u8 offset,
					u8 val)
{
	int err = 0;

	if (page == PLLMASK_ADDR_HI && offset == PLLMASK_ADDR_LO) {
		if ((val & 0xfc) || !(val & 0x3)) {
			dev_err(idt82p33->dev,
				"Invalid PLL mask 0x%x\n", val);
			err = -EINVAL;
		} else {
			idt82p33->pll_mask = val;
		}
	} else if (page == PLL0_OUTMASK_ADDR_HI &&
		offset == PLL0_OUTMASK_ADDR_LO) {
		idt82p33->channel[0].output_mask = val;
	} else if (page == PLL1_OUTMASK_ADDR_HI &&
		offset == PLL1_OUTMASK_ADDR_LO) {
		idt82p33->channel[1].output_mask = val;
	}

	return err;
}

static void idt82p33_display_masks(struct idt82p33 *idt82p33)
{
	u8 mask, i;

	dev_info(idt82p33->dev,
		 "pllmask = 0x%02x\n", idt82p33->pll_mask);

	for (i = 0; i < MAX_PHC_PLL; i++) {
		mask = 1 << i;

		if (mask & idt82p33->pll_mask)
			dev_info(idt82p33->dev,
				 "PLL%d output_mask = 0x%04x\n",
				 i, idt82p33->channel[i].output_mask);
	}
}

static int idt82p33_sync_tod(struct idt82p33_channel *channel, bool enable)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	u8 sync_cnfg;
	int err;

	err = idt82p33_read(idt82p33, channel->dpll_sync_cnfg,
			    &sync_cnfg, sizeof(sync_cnfg));
	if (err)
		return err;

	sync_cnfg &= ~SYNC_TOD;
	if (enable)
		sync_cnfg |= SYNC_TOD;

	return idt82p33_write(idt82p33, channel->dpll_sync_cnfg,
			      &sync_cnfg, sizeof(sync_cnfg));
}

static long idt82p33_work_handler(struct ptp_clock_info *ptp)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;

	mutex_lock(idt82p33->lock);
	(void)idt82p33_stop_ddco(channel);
	mutex_unlock(idt82p33->lock);

	/* Return a negative value here to not reschedule */
	return -1;
}

static int idt82p33_output_enable(struct idt82p33_channel *channel,
				  bool enable, unsigned int outn)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;
	u8 val;

	err = idt82p33_read(idt82p33, OUT_MUX_CNFG(outn), &val, sizeof(val));
	if (err)
		return err;
	if (enable)
		val &= ~SQUELCH_ENABLE;
	else
		val |= SQUELCH_ENABLE;

	return idt82p33_write(idt82p33, OUT_MUX_CNFG(outn), &val, sizeof(val));
}

static int idt82p33_perout_enable(struct idt82p33_channel *channel,
				  bool enable,
				  struct ptp_perout_request *perout)
{
	/* Enable/disable individual output instead */
	return idt82p33_output_enable(channel, enable, perout->index);
}

static int idt82p33_enable_tod(struct idt82p33_channel *channel)
{
	struct idt82p33 *idt82p33 = channel->idt82p33;
	struct timespec64 ts = {0, 0};
	int err;

	err = idt82p33_measure_tod_write_overhead(channel);

	if (err) {
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
		return err;
	}

	err = _idt82p33_settime(channel, &ts);

	if (err)
		return err;

	return idt82p33_sync_tod(channel, true);
}

static void idt82p33_ptp_clock_unregister_all(struct idt82p33 *idt82p33)
{
	struct idt82p33_channel *channel;
	u8 i;

	for (i = 0; i < MAX_PHC_PLL; i++) {
		channel = &idt82p33->channel[i];
		cancel_delayed_work_sync(&channel->adjtime_work);
		if (channel->ptp_clock)
			ptp_clock_unregister(channel->ptp_clock);
	}
}


static int idt82p33_enable(struct ptp_clock_info *ptp,
			   struct ptp_clock_request *rq, int on)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err = -EOPNOTSUPP;

	mutex_lock(idt82p33->lock);

	switch (rq->type) {
	case PTP_CLK_REQ_PEROUT:
		if (!on)
			err = idt82p33_perout_enable(channel, false,
						     &rq->perout);
		/* Only accept a 1-PPS aligned to the second. */
		else if (rq->perout.start.nsec || rq->perout.period.sec != 1 ||
			 rq->perout.period.nsec)
			err = -ERANGE;
		else
			err = idt82p33_perout_enable(channel, true,
						     &rq->perout);
		break;
	case PTP_CLK_REQ_EXTTS:
		err = idt82p33_extts_enable(channel, rq, on);
		break;
	default:
		break;
	}

	mutex_unlock(idt82p33->lock);

	if (err)
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
	return err;
}

static s32 idt82p33_getmaxphase(__always_unused struct ptp_clock_info *ptp)
{
	return WRITE_PHASE_OFFSET_LIMIT;
}

static int idt82p33_adjwritephase(struct ptp_clock_info *ptp, s32 offset_ns)
{
	struct idt82p33_channel *channel =
		container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	s64 offset_regval;
	u8 val[4] = {0};
	int err;

	/* Convert from phaseoffset_fs to register value */
	offset_regval = div_s64((s64)(-offset_ns) * 1000000000ll,
				IDT_T0DPLL_PHASE_RESOL);

	val[0] = offset_regval & 0xFF;
	val[1] = (offset_regval >> 8) & 0xFF;
	val[2] = (offset_regval >> 16) & 0xFF;
	val[3] = (offset_regval >> 24) & 0x1F;
	val[3] |= PH_OFFSET_EN;

	mutex_lock(idt82p33->lock);

	err = idt82p33_dpll_set_mode(channel, PLL_MODE_WPH);
	if (err) {
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
		goto out;
	}

	err = idt82p33_write(idt82p33, channel->dpll_phase_cnfg, val,
			     sizeof(val));

out:
	mutex_unlock(idt82p33->lock);
	return err;
}

static int idt82p33_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;

	if (channel->ddco == true)
		return 0;

	if (scaled_ppm == channel->current_freq)
		return 0;

	mutex_lock(idt82p33->lock);
	err = _idt82p33_adjfine(channel, scaled_ppm);

	if (err == 0)
		channel->current_freq = scaled_ppm;
	mutex_unlock(idt82p33->lock);

	if (err)
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
	return err;
}

static int idt82p33_adjtime(struct ptp_clock_info *ptp, s64 delta_ns)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;

	if (channel->ddco == true)
		return -EBUSY;

	mutex_lock(idt82p33->lock);

	if (abs(delta_ns) < phase_snap_threshold) {
		err = idt82p33_start_ddco(channel, delta_ns);
		mutex_unlock(idt82p33->lock);
		return err;
	}

	/* Use more accurate internal 1pps triggered write first */
	err = _idt82p33_adjtime_internal_triggered(channel, delta_ns);
	if (err && delta_ns > IMMEDIATE_SNAP_THRESHOLD_NS)
		err = _idt82p33_adjtime_immediate(channel, delta_ns);

	mutex_unlock(idt82p33->lock);

	if (err)
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
	return err;
}

static int idt82p33_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;

	mutex_lock(idt82p33->lock);
	err = _idt82p33_gettime(channel, ts);
	mutex_unlock(idt82p33->lock);

	if (err)
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
	return err;
}

static int idt82p33_settime(struct ptp_clock_info *ptp,
			    const struct timespec64 *ts)
{
	struct idt82p33_channel *channel =
			container_of(ptp, struct idt82p33_channel, caps);
	struct idt82p33 *idt82p33 = channel->idt82p33;
	int err;

	mutex_lock(idt82p33->lock);
	err = _idt82p33_settime(channel, ts);
	mutex_unlock(idt82p33->lock);

	if (err)
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
	return err;
}

static int idt82p33_channel_init(struct idt82p33 *idt82p33, u32 index)
{
	struct idt82p33_channel *channel = &idt82p33->channel[index];

	switch (index) {
	case 0:
		channel->dpll_tod_cnfg = DPLL1_TOD_CNFG;
		channel->dpll_tod_trigger = DPLL1_TOD_TRIGGER;
		channel->dpll_tod_sts = DPLL1_TOD_STS;
		channel->dpll_mode_cnfg = DPLL1_OPERATING_MODE_CNFG;
		channel->dpll_freq_cnfg = DPLL1_HOLDOVER_FREQ_CNFG;
		channel->dpll_phase_cnfg = DPLL1_PHASE_OFFSET_CNFG;
		channel->dpll_sync_cnfg = DPLL1_SYNC_EDGE_CNFG;
		channel->dpll_input_mode_cnfg = DPLL1_INPUT_MODE_CNFG;
		break;
	case 1:
		channel->dpll_tod_cnfg = DPLL2_TOD_CNFG;
		channel->dpll_tod_trigger = DPLL2_TOD_TRIGGER;
		channel->dpll_tod_sts = DPLL2_TOD_STS;
		channel->dpll_mode_cnfg = DPLL2_OPERATING_MODE_CNFG;
		channel->dpll_freq_cnfg = DPLL2_HOLDOVER_FREQ_CNFG;
		channel->dpll_phase_cnfg = DPLL2_PHASE_OFFSET_CNFG;
		channel->dpll_sync_cnfg = DPLL2_SYNC_EDGE_CNFG;
		channel->dpll_input_mode_cnfg = DPLL2_INPUT_MODE_CNFG;
		break;
	default:
		return -EINVAL;
	}

	channel->plln = index;
	channel->current_freq = 0;
	channel->idt82p33 = idt82p33;
	INIT_DELAYED_WORK(&channel->adjtime_work, idt82p33_adjtime_workaround);

	return 0;
}

static int idt82p33_verify_pin(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 -1;
	}
	return 0;
}

static void idt82p33_caps_init(u32 index, struct ptp_clock_info *caps,
			       struct ptp_pin_desc *pin_cfg, u8 max_pins)
{
	struct ptp_pin_desc *ppd;
	int i;

	caps->owner = THIS_MODULE;
	caps->max_adj = DCO_MAX_PPB;
	caps->n_per_out = MAX_PER_OUT;
	caps->n_ext_ts = MAX_PHC_PLL;
	caps->n_pins = max_pins;
	caps->adjphase = idt82p33_adjwritephase;
	caps->getmaxphase = idt82p33_getmaxphase;
	caps->adjfine = idt82p33_adjfine;
	caps->adjtime = idt82p33_adjtime;
	caps->gettime64 = idt82p33_gettime;
	caps->settime64 = idt82p33_settime;
	caps->enable = idt82p33_enable;
	caps->verify = idt82p33_verify_pin;
	caps->do_aux_work = idt82p33_work_handler;

	snprintf(caps->name, sizeof(caps->name), "IDT 82P33 PLL%u", index);

	caps->pin_config = pin_cfg;

	caps->supported_extts_flags = PTP_RISING_EDGE |
				      PTP_STRICT_FLAGS;

	for (i = 0; i < max_pins; ++i) {
		ppd = &pin_cfg[i];

		ppd->index = i;
		ppd->func = PTP_PF_NONE;
		ppd->chan = index;
		snprintf(ppd->name, sizeof(ppd->name), "in%d", 12 + i);
	}
}

static int idt82p33_enable_channel(struct idt82p33 *idt82p33, u32 index)
{
	struct idt82p33_channel *channel;
	int err;

	if (!(index < MAX_PHC_PLL))
		return -EINVAL;

	channel = &idt82p33->channel[index];

	err = idt82p33_channel_init(idt82p33, index);
	if (err) {
		dev_err(idt82p33->dev,
			"Channel_init failed in %s with err %d!\n",
			__func__, err);
		return err;
	}

	idt82p33_caps_init(index, &channel->caps,
			   pin_config[index], MAX_TRIG_CLK);

	channel->ptp_clock = ptp_clock_register(&channel->caps, NULL);

	if (IS_ERR(channel->ptp_clock)) {
		err = PTR_ERR(channel->ptp_clock);
		channel->ptp_clock = NULL;
		return err;
	}

	if (!channel->ptp_clock)
		return -ENOTSUPP;

	err = idt82p33_dpll_set_mode(channel, PLL_MODE_DCO);
	if (err) {
		dev_err(idt82p33->dev,
			"Dpll_set_mode failed in %s with err %d!\n",
			__func__, err);
		return err;
	}

	err = idt82p33_enable_tod(channel);
	if (err) {
		dev_err(idt82p33->dev,
			"Enable_tod failed in %s with err %d!\n",
			__func__, err);
		return err;
	}

	dev_info(idt82p33->dev, "PLL%d registered as ptp%d\n",
		 index, channel->ptp_clock->index);

	return 0;
}

static int idt82p33_reset(struct idt82p33 *idt82p33, bool cold)
{
	int err;
	u8 cfg = SOFT_RESET_EN;

	if (cold == true)
		goto cold_reset;

	err = idt82p33_read(idt82p33, REG_SOFT_RESET, &cfg, sizeof(cfg));
	if (err) {
		dev_err(idt82p33->dev,
			"Soft reset failed with err %d!\n", err);
		return err;
	}

	cfg |= SOFT_RESET_EN;

cold_reset:
	err = idt82p33_write(idt82p33, REG_SOFT_RESET, &cfg, sizeof(cfg));
	if (err)
		dev_err(idt82p33->dev,
			"Cold reset failed with err %d!\n", err);
	return err;
}

static int idt82p33_load_firmware(struct idt82p33 *idt82p33)
{
	char fname[128] = FW_FILENAME;
	const struct firmware *fw;
	struct idt82p33_fwrc *rec;
	u8 loaddr, page, val;
	int err;
	s32 len;

	if (firmware) /* module parameter */
		snprintf(fname, sizeof(fname), "%s", firmware);

	dev_info(idt82p33->dev, "requesting firmware '%s'\n", fname);

	err = request_firmware(&fw, fname, idt82p33->dev);

	if (err) {
		dev_err(idt82p33->dev,
			"Failed in %s with err %d!\n", __func__, err);
		return err;
	}

	dev_dbg(idt82p33->dev, "firmware size %zu bytes\n", fw->size);

	rec = (struct idt82p33_fwrc *) fw->data;

	for (len = fw->size; len > 0; len -= sizeof(*rec)) {

		if (rec->reserved) {
			dev_err(idt82p33->dev,
				"bad firmware, reserved field non-zero\n");
			err = -EINVAL;
		} else {
			val = rec->value;
			loaddr = rec->loaddr;
			page = rec->hiaddr;

			rec++;

			err = idt82p33_check_and_set_masks(idt82p33, page,
							   loaddr, val);
		}

		if (err == 0) {
			/* Page size 128, last 4 bytes of page skipped */
			if (loaddr > 0x7b)
				continue;

			err = idt82p33_write(idt82p33, REG_ADDR(page, loaddr),
					     &val, sizeof(val));
		}

		if (err)
			goto out;
	}

	idt82p33_display_masks(idt82p33);
out:
	release_firmware(fw);
	return err;
}

static void idt82p33_extts_check(struct work_struct *work)
{
	struct idt82p33 *idt82p33 = container_of(work, struct idt82p33,
						 extts_work.work);
	struct idt82p33_channel *channel;
	int err;
	u8 mask;
	int i;

	if (idt82p33->extts_mask == 0)
		return;

	mutex_lock(idt82p33->lock);

	for (i = 0; i < MAX_PHC_PLL; i++) {
		mask = 1 << i;

		if ((idt82p33->extts_mask & mask) == 0)
			continue;

		err = idt82p33_extts_check_channel(idt82p33, i);

		if (err == 0) {
			/* trigger clears itself, so clear the mask */
			if (idt82p33->extts_single_shot) {
				idt82p33->extts_mask &= ~mask;
			} else {
				/* Re-arm */
				channel = &idt82p33->channel[i];
				arm_tod_read_with_trigger(channel, channel->tod_trigger);
			}
		}
	}

	if (idt82p33->extts_mask)
		schedule_delayed_work(&idt82p33->extts_work,
				      msecs_to_jiffies(EXTTS_PERIOD_MS));

	mutex_unlock(idt82p33->lock);
}

static int idt82p33_probe(struct platform_device *pdev)
{
	struct rsmu_ddata *ddata = dev_get_drvdata(pdev->dev.parent);
	struct idt82p33 *idt82p33;
	int err;
	u8 i;

	idt82p33 = devm_kzalloc(&pdev->dev,
				sizeof(struct idt82p33), GFP_KERNEL);
	if (!idt82p33)
		return -ENOMEM;

	idt82p33->dev = &pdev->dev;
	idt82p33->mfd = pdev->dev.parent;
	idt82p33->lock = &ddata->lock;
	idt82p33->regmap = ddata->regmap;
	idt82p33->tod_write_overhead_ns = 0;
	idt82p33->calculate_overhead_flag = 0;
	idt82p33->pll_mask = DEFAULT_PLL_MASK;
	idt82p33->channel[0].output_mask = DEFAULT_OUTPUT_MASK_PLL0;
	idt82p33->channel[1].output_mask = DEFAULT_OUTPUT_MASK_PLL1;
	idt82p33->extts_mask = 0;
	INIT_DELAYED_WORK(&idt82p33->extts_work, idt82p33_extts_check);

	mutex_lock(idt82p33->lock);

	/* cold reset before loading firmware */
	idt82p33_reset(idt82p33, true);

	err = idt82p33_load_firmware(idt82p33);
	if (err)
		dev_warn(idt82p33->dev,
			 "loading firmware failed with %d\n", err);

	/* soft reset after loading firmware */
	idt82p33_reset(idt82p33, false);

	if (idt82p33->pll_mask) {
		for (i = 0; i < MAX_PHC_PLL; i++) {
			if (idt82p33->pll_mask & (1 << i))
				err = idt82p33_enable_channel(idt82p33, i);
			else
				err = idt82p33_channel_init(idt82p33, i);
			if (err) {
				dev_err(idt82p33->dev,
					"Failed in %s with err %d!\n",
					__func__, err);
				break;
			}
		}
	} else {
		dev_err(idt82p33->dev,
			"no PLLs flagged as PHCs, nothing to do\n");
		err = -ENODEV;
	}

	mutex_unlock(idt82p33->lock);

	if (err) {
		idt82p33_ptp_clock_unregister_all(idt82p33);
		return err;
	}

	platform_set_drvdata(pdev, idt82p33);

	return 0;
}

static void idt82p33_remove(struct platform_device *pdev)
{
	struct idt82p33 *idt82p33 = platform_get_drvdata(pdev);

	cancel_delayed_work_sync(&idt82p33->extts_work);

	idt82p33_ptp_clock_unregister_all(idt82p33);
}

static struct platform_driver idt82p33_driver = {
	.driver = {
		.name = "82p33x1x-phc",
	},
	.probe = idt82p33_probe,
	.remove = idt82p33_remove,
};

module_platform_driver(idt82p33_driver);