root/drivers/ptp/ptp_idt82p33.c
// 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);