1 files changed, 1014 insertions, 0 deletions

diff --git a/drivers/ptp/ptp_fc3.c b/drivers/ptp/ptp_fc3.c
new file mode 100644
index 0000000000..6ef982862e
--- /dev/null
+++ b/drivers/ptp/ptp_fc3.c
@@ -0,0 +1,1014 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PTP hardware clock driver for the FemtoClock3 family of timing and
+ * synchronization devices.
+ *
+ * Copyright (C) 2023 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#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/string.h>
+#include <linux/of.h>
+#include <linux/bitfield.h>
+#include <linux/mfd/rsmu.h>
+#include <linux/mfd/idtRC38xxx_reg.h>
+#include <asm/unaligned.h>
+
+#include "ptp_private.h"
+#include "ptp_fc3.h"
+
+MODULE_DESCRIPTION("Driver for IDT FemtoClock3(TM) family");
+MODULE_AUTHOR("IDT support-1588 <IDT-support-1588@lm.renesas.com>");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");
+
+/*
+ * The name of the firmware file to be loaded
+ * over-rides any automatic selection
+ */
+static char *firmware;
+module_param(firmware, charp, 0);
+
+static s64 ns2counters(struct idtfc3 *idtfc3, s64 nsec, u32 *sub_ns)
+{
+	s64 sync;
+	s32 rem;
+
+	if (likely(nsec >= 0)) {
+		sync = div_u64_rem(nsec, idtfc3->ns_per_sync, &rem);
+		*sub_ns = rem;
+	} else {
+		sync = -div_u64_rem(-nsec - 1, idtfc3->ns_per_sync, &rem) - 1;
+		*sub_ns = idtfc3->ns_per_sync - rem - 1;
+	}
+
+	return sync * idtfc3->ns_per_sync;
+}
+
+static s64 tdc_meas2offset(struct idtfc3 *idtfc3, u64 meas_read)
+{
+	s64 coarse, fine;
+
+	fine = sign_extend64(FIELD_GET(FINE_MEAS_MASK, meas_read), 12);
+	coarse = sign_extend64(FIELD_GET(COARSE_MEAS_MASK, meas_read), (39 - 13));
+
+	fine = div64_s64(fine * NSEC_PER_SEC, idtfc3->tdc_apll_freq * 62LL);
+	coarse = div64_s64(coarse * NSEC_PER_SEC, idtfc3->time_ref_freq);
+
+	return coarse + fine;
+}
+
+static s64 tdc_offset2phase(struct idtfc3 *idtfc3, s64 offset_ns)
+{
+	if (offset_ns > idtfc3->ns_per_sync / 2)
+		offset_ns -= idtfc3->ns_per_sync;
+
+	return offset_ns * idtfc3->tdc_offset_sign;
+}
+
+static int idtfc3_set_lpf_mode(struct idtfc3 *idtfc3, u8 mode)
+{
+	int err;
+
+	if (mode >= LPF_INVALID)
+		return -EINVAL;
+
+	if (idtfc3->lpf_mode == mode)
+		return 0;
+
+	err = regmap_bulk_write(idtfc3->regmap, LPF_MODE_CNFG, &mode, sizeof(mode));
+	if (err)
+		return err;
+
+	idtfc3->lpf_mode = mode;
+
+	return 0;
+}
+
+static int idtfc3_enable_lpf(struct idtfc3 *idtfc3, bool enable)
+{
+	u8 val;
+	int err;
+
+	err = regmap_bulk_read(idtfc3->regmap, LPF_CTRL, &val, sizeof(val));
+	if (err)
+		return err;
+
+	if (enable == true)
+		val |= LPF_EN;
+	else
+		val &= ~LPF_EN;
+
+	return regmap_bulk_write(idtfc3->regmap, LPF_CTRL, &val, sizeof(val));
+}
+
+static int idtfc3_get_time_ref_freq(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 buf[4];
+	u8 time_ref_div;
+	u8 time_clk_div;
+
+	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_MEAS_DIV_CNFG, buf, sizeof(buf));
+	if (err)
+		return err;
+	time_ref_div = FIELD_GET(TIME_REF_DIV_MASK, get_unaligned_le32(buf)) + 1;
+
+	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_COUNT, buf, 1);
+	if (err)
+		return err;
+	time_clk_div = (buf[0] & TIME_CLOCK_COUNT_MASK) + 1;
+	idtfc3->time_ref_freq = idtfc3->hw_param.time_clk_freq *
+				time_clk_div / time_ref_div;
+
+	return 0;
+}
+
+static int idtfc3_get_tdc_offset_sign(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 buf[4];
+	u32 val;
+	u8 sig1, sig2;
+
+	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_TDC_FANOUT_CNFG, buf, sizeof(buf));
+	if (err)
+		return err;
+
+	val = get_unaligned_le32(buf);
+	if ((val & TIME_SYNC_TO_TDC_EN) != TIME_SYNC_TO_TDC_EN) {
+		dev_err(idtfc3->dev, "TIME_SYNC_TO_TDC_EN is off !!!");
+		return -EINVAL;
+	}
+
+	sig1 = FIELD_GET(SIG1_MUX_SEL_MASK, val);
+	sig2 = FIELD_GET(SIG2_MUX_SEL_MASK, val);
+
+	if ((sig1 == sig2) || ((sig1 != TIME_SYNC) && (sig2 != TIME_SYNC))) {
+		dev_err(idtfc3->dev, "Invalid tdc_mux_sel sig1=%d sig2=%d", sig1, sig2);
+		return -EINVAL;
+	} else if (sig1 == TIME_SYNC) {
+		idtfc3->tdc_offset_sign = 1;
+	} else if (sig2 == TIME_SYNC) {
+		idtfc3->tdc_offset_sign = -1;
+	}
+
+	return 0;
+}
+
+static int idtfc3_lpf_bw(struct idtfc3 *idtfc3, u8 shift, u8 mult)
+{
+	u8 val = FIELD_PREP(LPF_BW_SHIFT, shift) | FIELD_PREP(LPF_BW_MULT, mult);
+
+	return regmap_bulk_write(idtfc3->regmap, LPF_BW_CNFG, &val, sizeof(val));
+}
+
+static int idtfc3_enable_tdc(struct idtfc3 *idtfc3, bool enable, u8 meas_mode)
+{
+	int err;
+	u8 val = 0;
+
+	/* Disable TDC first */
+	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CTRL, &val, sizeof(val));
+	if (err)
+		return err;
+
+	if (enable == false)
+		return idtfc3_lpf_bw(idtfc3, LPF_BW_SHIFT_DEFAULT, LPF_BW_MULT_DEFAULT);
+
+	if (meas_mode >= MEAS_MODE_INVALID)
+		return -EINVAL;
+
+	/* Change TDC meas mode */
+	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CNFG,
+				&meas_mode, sizeof(meas_mode));
+	if (err)
+		return err;
+
+	/* Enable TDC */
+	val = TDC_MEAS_EN;
+	if (meas_mode == CONTINUOUS)
+		val |= TDC_MEAS_START;
+	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CTRL, &val, sizeof(val));
+	if (err)
+		return err;
+
+	return idtfc3_lpf_bw(idtfc3, LPF_BW_SHIFT_1PPS, LPF_BW_MULT_DEFAULT);
+}
+
+static bool get_tdc_meas(struct idtfc3 *idtfc3, s64 *offset_ns)
+{
+	bool valid = false;
+	u8 buf[9];
+	u8 val;
+	int err;
+
+	while (true) {
+		err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_STS,
+				       &val, sizeof(val));
+		if (err)
+			return false;
+
+		if (val & FIFO_EMPTY)
+			break;
+
+		err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_READ_REQ,
+				       &buf, sizeof(buf));
+		if (err)
+			return false;
+
+		valid = true;
+	}
+
+	if (valid)
+		*offset_ns = tdc_meas2offset(idtfc3, get_unaligned_le64(&buf[1]));
+
+	return valid;
+}
+
+static int check_tdc_fifo_overrun(struct idtfc3 *idtfc3)
+{
+	u8 val;
+	int err;
+
+	/* Check if FIFO is overrun */
+	err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_STS, &val, sizeof(val));
+	if (err)
+		return err;
+
+	if (!(val & FIFO_FULL))
+		return 0;
+
+	dev_warn(idtfc3->dev, "TDC FIFO overrun !!!");
+
+	err = idtfc3_enable_tdc(idtfc3, true, CONTINUOUS);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int get_tdc_meas_continuous(struct idtfc3 *idtfc3)
+{
+	int err;
+	s64 offset_ns;
+	struct ptp_clock_event event;
+
+	err = check_tdc_fifo_overrun(idtfc3);
+	if (err)
+		return err;
+
+	if (get_tdc_meas(idtfc3, &offset_ns) && offset_ns >= 0) {
+		event.index = 0;
+		event.offset = tdc_offset2phase(idtfc3, offset_ns);
+		event.type = PTP_CLOCK_EXTOFF;
+		ptp_clock_event(idtfc3->ptp_clock, &event);
+	}
+
+	return 0;
+}
+
+static int idtfc3_read_subcounter(struct idtfc3 *idtfc3)
+{
+	u8 buf[5] = {0};
+	int err;
+
+	err = regmap_bulk_read(idtfc3->regmap, TOD_COUNTER_READ_REQ,
+			       &buf, sizeof(buf));
+	if (err)
+		return err;
+
+	/* sync_counter_value is [31:82] and sub_sync_counter_value is [0:30] */
+	return get_unaligned_le32(&buf[1]) & SUB_SYNC_COUNTER_MASK;
+}
+
+static int idtfc3_tod_update_is_done(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 req;
+
+	err = read_poll_timeout_atomic(regmap_bulk_read, err, !req, USEC_PER_MSEC,
+				       idtfc3->tc_write_timeout, true, idtfc3->regmap,
+				       TOD_SYNC_LOAD_REQ_CTRL, &req, 1);
+	if (err)
+		dev_err(idtfc3->dev, "TOD counter write timeout !!!");
+
+	return err;
+}
+
+static int idtfc3_write_subcounter(struct idtfc3 *idtfc3, u32 counter)
+{
+	u8 buf[18] = {0};
+	int err;
+
+	/* sync_counter_value is [31:82] and sub_sync_counter_value is [0:30] */
+	put_unaligned_le32(counter & SUB_SYNC_COUNTER_MASK, &buf[0]);
+
+	buf[16] = SUB_SYNC_LOAD_ENABLE | SYNC_LOAD_ENABLE;
+	buf[17] = SYNC_LOAD_REQ;
+
+	err = regmap_bulk_write(idtfc3->regmap, TOD_SYNC_LOAD_VAL_CTRL,
+				&buf, sizeof(buf));
+	if (err)
+		return err;
+
+	return idtfc3_tod_update_is_done(idtfc3);
+}
+
+static int idtfc3_timecounter_update(struct idtfc3 *idtfc3, u32 counter, s64 ns)
+{
+	int err;
+
+	err = idtfc3_write_subcounter(idtfc3, counter);
+	if (err)
+		return err;
+
+	/* Update time counter */
+	idtfc3->ns = ns;
+	idtfc3->last_counter = counter;
+
+	return 0;
+}
+
+static int idtfc3_timecounter_read(struct idtfc3 *idtfc3)
+{
+	int now, delta;
+
+	now = idtfc3_read_subcounter(idtfc3);
+	if (now < 0)
+		return now;
+
+	/* calculate the delta since the last idtfc3_timecounter_read(): */
+	if (now >= idtfc3->last_counter)
+		delta = now - idtfc3->last_counter;
+	else
+		delta = idtfc3->sub_sync_count - idtfc3->last_counter + now;
+
+	/* Update time counter */
+	idtfc3->ns += delta * idtfc3->ns_per_counter;
+	idtfc3->last_counter = now;
+
+	return 0;
+}
+
+static int _idtfc3_gettime(struct idtfc3 *idtfc3, struct timespec64 *ts)
+{
+	int err;
+
+	err = idtfc3_timecounter_read(idtfc3);
+	if (err)
+		return err;
+
+	*ts = ns_to_timespec64(idtfc3->ns);
+
+	return 0;
+}
+
+static int idtfc3_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err;
+
+	mutex_lock(idtfc3->lock);
+	err = _idtfc3_gettime(idtfc3, ts);
+	mutex_unlock(idtfc3->lock);
+
+	return err;
+}
+
+static int _idtfc3_settime(struct idtfc3 *idtfc3, const struct timespec64 *ts)
+{
+	s64 offset_ns, now_ns;
+	u32 counter, sub_ns;
+	int now;
+
+	if (timespec64_valid(ts) == false) {
+		dev_err(idtfc3->dev, "%s: invalid timespec", __func__);
+		return -EINVAL;
+	}
+
+	now = idtfc3_read_subcounter(idtfc3);
+	if (now < 0)
+		return now;
+
+	offset_ns = (idtfc3->sub_sync_count - now) * idtfc3->ns_per_counter;
+	now_ns = timespec64_to_ns(ts);
+	(void)ns2counters(idtfc3, offset_ns + now_ns, &sub_ns);
+
+	counter = sub_ns / idtfc3->ns_per_counter;
+	return idtfc3_timecounter_update(idtfc3, counter, now_ns);
+}
+
+static int idtfc3_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err;
+
+	mutex_lock(idtfc3->lock);
+	err = _idtfc3_settime(idtfc3, ts);
+	mutex_unlock(idtfc3->lock);
+
+	return err;
+}
+
+static int _idtfc3_adjtime(struct idtfc3 *idtfc3, s64 delta)
+{
+	/*
+	 * The TOD counter can be synchronously loaded with any value,
+	 * to be loaded on the next Time Sync pulse
+	 */
+	s64 sync_ns;
+	u32 sub_ns;
+	u32 counter;
+
+	if (idtfc3->ns + delta < 0) {
+		dev_err(idtfc3->dev, "%lld ns adj is too large", delta);
+		return -EINVAL;
+	}
+
+	sync_ns = ns2counters(idtfc3, delta + idtfc3->ns_per_sync, &sub_ns);
+
+	counter = sub_ns / idtfc3->ns_per_counter;
+	return idtfc3_timecounter_update(idtfc3, counter, idtfc3->ns + sync_ns +
+									counter * idtfc3->ns_per_counter);
+}
+
+static int idtfc3_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err;
+
+	mutex_lock(idtfc3->lock);
+	err = _idtfc3_adjtime(idtfc3, delta);
+	mutex_unlock(idtfc3->lock);
+
+	return err;
+}
+
+static int _idtfc3_adjphase(struct idtfc3 *idtfc3, s32 delta)
+{
+	u8 buf[8] = {0};
+	int err;
+	s64 pcw;
+
+	err = idtfc3_set_lpf_mode(idtfc3, LPF_WP);
+	if (err)
+		return err;
+
+	/*
+	 * Phase Control Word unit is: 10^9 / (TDC_APLL_FREQ * 124)
+	 *
+	 *       delta * TDC_APLL_FREQ * 124
+	 * PCW = ---------------------------
+	 *                  10^9
+	 *
+	 */
+	pcw = div_s64((s64)delta * idtfc3->tdc_apll_freq * 124, NSEC_PER_SEC);
+
+	put_unaligned_le64(pcw, buf);
+
+	return regmap_bulk_write(idtfc3->regmap, LPF_WR_PHASE_CTRL, buf, sizeof(buf));
+}
+
+static int idtfc3_adjphase(struct ptp_clock_info *ptp, s32 delta)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err;
+
+	mutex_lock(idtfc3->lock);
+	err = _idtfc3_adjphase(idtfc3, delta);
+	mutex_unlock(idtfc3->lock);
+
+	return err;
+}
+
+static int _idtfc3_adjfine(struct idtfc3 *idtfc3, long scaled_ppm)
+{
+	u8 buf[8] = {0};
+	int err;
+	s64 fcw;
+
+	err = idtfc3_set_lpf_mode(idtfc3, LPF_WF);
+	if (err)
+		return err;
+
+	/*
+	 * Frequency Control Word unit is: 2^-44 * 10^6 ppm
+	 *
+	 * adjfreq:
+	 *       ppb * 2^44
+	 * FCW = ----------
+	 *          10^9
+	 *
+	 * adjfine:
+	 *       ppm_16 * 2^28
+	 * FCW = -------------
+	 *           10^6
+	 */
+	fcw = scaled_ppm * BIT(28);
+	fcw = div_s64(fcw, 1000000);
+
+	put_unaligned_le64(fcw, buf);
+
+	return regmap_bulk_write(idtfc3->regmap, LPF_WR_FREQ_CTRL, buf, sizeof(buf));
+}
+
+static int idtfc3_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err;
+
+	mutex_lock(idtfc3->lock);
+	err = _idtfc3_adjfine(idtfc3, scaled_ppm);
+	mutex_unlock(idtfc3->lock);
+
+	return err;
+}
+
+static int idtfc3_enable(struct ptp_clock_info *ptp,
+			 struct ptp_clock_request *rq, int on)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	int err = -EOPNOTSUPP;
+
+	mutex_lock(idtfc3->lock);
+	switch (rq->type) {
+	case PTP_CLK_REQ_PEROUT:
+		if (!on)
+			err = 0;
+		/* 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 = 0;
+		break;
+	case PTP_CLK_REQ_EXTTS:
+		if (on) {
+			/* Only accept requests for external phase offset */
+			if ((rq->extts.flags & PTP_EXT_OFFSET) != (PTP_EXT_OFFSET))
+				err = -EOPNOTSUPP;
+			else
+				err = idtfc3_enable_tdc(idtfc3, true, CONTINUOUS);
+		} else {
+			err = idtfc3_enable_tdc(idtfc3, false, MEAS_MODE_INVALID);
+		}
+		break;
+	default:
+		break;
+	}
+	mutex_unlock(idtfc3->lock);
+
+	if (err)
+		dev_err(idtfc3->dev, "Failed in %s with err %d!", __func__, err);
+
+	return err;
+}
+
+static long idtfc3_aux_work(struct ptp_clock_info *ptp)
+{
+	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
+	static int tdc_get;
+
+	mutex_lock(idtfc3->lock);
+	tdc_get %= TDC_GET_PERIOD;
+	if ((tdc_get == 0) || (tdc_get == TDC_GET_PERIOD / 2))
+		idtfc3_timecounter_read(idtfc3);
+	get_tdc_meas_continuous(idtfc3);
+	tdc_get++;
+	mutex_unlock(idtfc3->lock);
+
+	return idtfc3->tc_update_period;
+}
+
+static const struct ptp_clock_info idtfc3_caps = {
+	.owner		= THIS_MODULE,
+	.max_adj	= MAX_FFO_PPB,
+	.n_per_out	= 1,
+	.n_ext_ts	= 1,
+	.adjphase	= &idtfc3_adjphase,
+	.adjfine	= &idtfc3_adjfine,
+	.adjtime	= &idtfc3_adjtime,
+	.gettime64	= &idtfc3_gettime,
+	.settime64	= &idtfc3_settime,
+	.enable		= &idtfc3_enable,
+	.do_aux_work	= &idtfc3_aux_work,
+};
+
+static int idtfc3_hw_calibrate(struct idtfc3 *idtfc3)
+{
+	int err = 0;
+	u8 val;
+
+	mdelay(10);
+	/*
+	 * Toggle TDC_DAC_RECAL_REQ:
+	 * (1) set tdc_en to 1
+	 * (2) set tdc_dac_recal_req to 0
+	 * (3) set tdc_dac_recal_req to 1
+	 */
+	val = TDC_EN;
+	err = regmap_bulk_write(idtfc3->regmap, TDC_CTRL,
+				&val, sizeof(val));
+	if (err)
+		return err;
+	val = TDC_EN | TDC_DAC_RECAL_REQ;
+	err = regmap_bulk_write(idtfc3->regmap, TDC_CTRL,
+				&val, sizeof(val));
+	if (err)
+		return err;
+	mdelay(10);
+
+	/*
+	 * Toggle APLL_REINIT:
+	 * (1) set apll_reinit to 0
+	 * (2) set apll_reinit to 1
+	 */
+	val = 0;
+	err = regmap_bulk_write(idtfc3->regmap, SOFT_RESET_CTRL,
+				&val, sizeof(val));
+	if (err)
+		return err;
+	val = APLL_REINIT;
+	err = regmap_bulk_write(idtfc3->regmap, SOFT_RESET_CTRL,
+				&val, sizeof(val));
+	if (err)
+		return err;
+	mdelay(10);
+
+	return err;
+}
+
+static int idtfc3_init_timecounter(struct idtfc3 *idtfc3)
+{
+	int err;
+	u32 period_ms;
+
+	period_ms = idtfc3->sub_sync_count * MSEC_PER_SEC /
+			idtfc3->hw_param.time_clk_freq;
+
+	idtfc3->tc_update_period = msecs_to_jiffies(period_ms / TDC_GET_PERIOD);
+	idtfc3->tc_write_timeout = period_ms * USEC_PER_MSEC;
+
+	err = idtfc3_timecounter_update(idtfc3, 0, 0);
+	if (err)
+		return err;
+
+	err = idtfc3_timecounter_read(idtfc3);
+	if (err)
+		return err;
+
+	ptp_schedule_worker(idtfc3->ptp_clock, idtfc3->tc_update_period);
+
+	return 0;
+}
+
+static int idtfc3_get_tdc_apll_freq(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 tdc_fb_div_int;
+	u8 tdc_ref_div;
+	struct idtfc3_hw_param *param = &idtfc3->hw_param;
+
+	err = regmap_bulk_read(idtfc3->regmap, TDC_REF_DIV_CNFG,
+				&tdc_ref_div, sizeof(tdc_ref_div));
+	if (err)
+		return err;
+
+	err = regmap_bulk_read(idtfc3->regmap, TDC_FB_DIV_INT_CNFG,
+				&tdc_fb_div_int, sizeof(tdc_fb_div_int));
+	if (err)
+		return err;
+
+	tdc_fb_div_int &= TDC_FB_DIV_INT_MASK;
+	tdc_ref_div &= TDC_REF_DIV_CONFIG_MASK;
+
+	idtfc3->tdc_apll_freq = div_u64(param->xtal_freq * (u64)tdc_fb_div_int,
+					1 << tdc_ref_div);
+
+	return 0;
+}
+
+static int idtfc3_get_fod(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 fod;
+
+	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_SRC, &fod, sizeof(fod));
+	if (err)
+		return err;
+
+	switch (fod) {
+	case 0:
+		idtfc3->fod_n = FOD_0;
+		break;
+	case 1:
+		idtfc3->fod_n = FOD_1;
+		break;
+	case 2:
+		idtfc3->fod_n = FOD_2;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int idtfc3_get_sync_count(struct idtfc3 *idtfc3)
+{
+	int err;
+	u8 buf[4];
+
+	err = regmap_bulk_read(idtfc3->regmap, SUB_SYNC_GEN_CNFG, buf, sizeof(buf));
+	if (err)
+		return err;
+
+	idtfc3->sub_sync_count = (get_unaligned_le32(buf) & SUB_SYNC_COUNTER_MASK) + 1;
+	idtfc3->ns_per_counter = NSEC_PER_SEC / idtfc3->hw_param.time_clk_freq;
+	idtfc3->ns_per_sync = idtfc3->sub_sync_count * idtfc3->ns_per_counter;
+
+	return 0;
+}
+
+static int idtfc3_setup_hw_param(struct idtfc3 *idtfc3)
+{
+	int err;
+
+	err = idtfc3_get_fod(idtfc3);
+	if (err)
+		return err;
+
+	err = idtfc3_get_sync_count(idtfc3);
+	if (err)
+		return err;
+
+	err = idtfc3_get_time_ref_freq(idtfc3);
+	if (err)
+		return err;
+
+	return idtfc3_get_tdc_apll_freq(idtfc3);
+}
+
+static int idtfc3_configure_hw(struct idtfc3 *idtfc3)
+{
+	int err = 0;
+
+	err = idtfc3_hw_calibrate(idtfc3);
+	if (err)
+		return err;
+
+	err = idtfc3_enable_lpf(idtfc3, true);
+	if (err)
+		return err;
+
+	err = idtfc3_enable_tdc(idtfc3, false, MEAS_MODE_INVALID);
+	if (err)
+		return err;
+
+	err = idtfc3_get_tdc_offset_sign(idtfc3);
+	if (err)
+		return err;
+
+	return idtfc3_setup_hw_param(idtfc3);
+}
+
+static int idtfc3_set_overhead(struct idtfc3 *idtfc3)
+{
+	s64 current_ns = 0;
+	s64 lowest_ns = 0;
+	int err;
+	u8 i;
+	ktime_t start;
+	ktime_t stop;
+	ktime_t diff;
+
+	char buf[18] = {0};
+
+	for (i = 0; i < 5; i++) {
+		start = ktime_get_raw();
+
+		err = regmap_bulk_write(idtfc3->regmap, TOD_SYNC_LOAD_VAL_CTRL,
+					&buf, sizeof(buf));
+		if (err)
+			return err;
+
+		stop = ktime_get_raw();
+
+		diff = ktime_sub(stop, start);
+
+		current_ns = ktime_to_ns(diff);
+
+		if (i == 0) {
+			lowest_ns = current_ns;
+		} else {
+			if (current_ns < lowest_ns)
+				lowest_ns = current_ns;
+		}
+	}
+
+	idtfc3->tod_write_overhead = lowest_ns;
+
+	return err;
+}
+
+static int idtfc3_enable_ptp(struct idtfc3 *idtfc3)
+{
+	int err;
+
+	idtfc3->caps = idtfc3_caps;
+	snprintf(idtfc3->caps.name, sizeof(idtfc3->caps.name), "IDT FC3W");
+	idtfc3->ptp_clock = ptp_clock_register(&idtfc3->caps, NULL);
+
+	if (IS_ERR(idtfc3->ptp_clock)) {
+		err = PTR_ERR(idtfc3->ptp_clock);
+		idtfc3->ptp_clock = NULL;
+		return err;
+	}
+
+	err = idtfc3_set_overhead(idtfc3);
+	if (err)
+		return err;
+
+	err = idtfc3_init_timecounter(idtfc3);
+	if (err)
+		return err;
+
+	dev_info(idtfc3->dev, "TIME_SYNC_CHANNEL registered as ptp%d",
+		 idtfc3->ptp_clock->index);
+
+	return 0;
+}
+
+static int idtfc3_load_firmware(struct idtfc3 *idtfc3)
+{
+	char fname[128] = FW_FILENAME;
+	const struct firmware *fw;
+	struct idtfc3_fwrc *rec;
+	u16 addr;
+	u8 val;
+	int err;
+	s32 len;
+
+	idtfc3_default_hw_param(&idtfc3->hw_param);
+
+	if (firmware) /* module parameter */
+		snprintf(fname, sizeof(fname), "%s", firmware);
+
+	dev_info(idtfc3->dev, "requesting firmware '%s'\n", fname);
+
+	err = request_firmware(&fw, fname, idtfc3->dev);
+
+	if (err) {
+		dev_err(idtfc3->dev,
+			"requesting firmware failed with err %d!\n", err);
+		return err;
+	}
+
+	dev_dbg(idtfc3->dev, "firmware size %zu bytes\n", fw->size);
+
+	rec = (struct idtfc3_fwrc *)fw->data;
+
+	for (len = fw->size; len > 0; len -= sizeof(*rec)) {
+		if (rec->reserved) {
+			dev_err(idtfc3->dev,
+				"bad firmware, reserved field non-zero\n");
+			err = -EINVAL;
+		} else {
+			val = rec->value;
+			addr = rec->hiaddr << 8 | rec->loaddr;
+
+			rec++;
+
+			err = idtfc3_set_hw_param(&idtfc3->hw_param, addr, val);
+		}
+
+		if (err != -EINVAL) {
+			err = 0;
+
+			/* Max register */
+			if (addr >= 0xE88)
+				continue;
+
+			err = regmap_bulk_write(idtfc3->regmap, addr,
+						&val, sizeof(val));
+		}
+
+		if (err)
+			goto out;
+	}
+
+	err = idtfc3_configure_hw(idtfc3);
+out:
+	release_firmware(fw);
+	return err;
+}
+
+static int idtfc3_read_device_id(struct idtfc3 *idtfc3, u16 *device_id)
+{
+	int err;
+	u8 buf[2] = {0};
+
+	err = regmap_bulk_read(idtfc3->regmap, DEVICE_ID,
+			       &buf, sizeof(buf));
+	if (err) {
+		dev_err(idtfc3->dev, "%s failed with %d", __func__, err);
+		return err;
+	}
+
+	*device_id = get_unaligned_le16(buf);
+
+	return 0;
+}
+
+static int idtfc3_check_device_compatibility(struct idtfc3 *idtfc3)
+{
+	int err;
+	u16 device_id;
+
+	err = idtfc3_read_device_id(idtfc3, &device_id);
+	if (err)
+		return err;
+
+	if ((device_id & DEVICE_ID_MASK) == 0) {
+		dev_err(idtfc3->dev, "invalid device");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int idtfc3_probe(struct platform_device *pdev)
+{
+	struct rsmu_ddata *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct idtfc3 *idtfc3;
+	int err;
+
+	idtfc3 = devm_kzalloc(&pdev->dev, sizeof(struct idtfc3), GFP_KERNEL);
+
+	if (!idtfc3)
+		return -ENOMEM;
+
+	idtfc3->dev = &pdev->dev;
+	idtfc3->mfd = pdev->dev.parent;
+	idtfc3->lock = &ddata->lock;
+	idtfc3->regmap = ddata->regmap;
+
+	mutex_lock(idtfc3->lock);
+
+	err = idtfc3_check_device_compatibility(idtfc3);
+	if (err) {
+		mutex_unlock(idtfc3->lock);
+		return err;
+	}
+
+	err = idtfc3_load_firmware(idtfc3);
+	if (err) {
+		if (err == -ENOENT) {
+			mutex_unlock(idtfc3->lock);
+			return -EPROBE_DEFER;
+		}
+		dev_warn(idtfc3->dev, "loading firmware failed with %d", err);
+	}
+
+	err = idtfc3_enable_ptp(idtfc3);
+	if (err) {
+		dev_err(idtfc3->dev, "idtfc3_enable_ptp failed with %d", err);
+		mutex_unlock(idtfc3->lock);
+		return err;
+	}
+
+	mutex_unlock(idtfc3->lock);
+
+	if (err) {
+		ptp_clock_unregister(idtfc3->ptp_clock);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, idtfc3);
+
+	return 0;
+}
+
+static void idtfc3_remove(struct platform_device *pdev)
+{
+	struct idtfc3 *idtfc3 = platform_get_drvdata(pdev);
+
+	ptp_clock_unregister(idtfc3->ptp_clock);
+}
+
+static struct platform_driver idtfc3_driver = {
+	.driver = {
+		.name = "rc38xxx-phc",
+	},
+	.probe = idtfc3_probe,
+	.remove_new = idtfc3_remove,
+};
+
+module_platform_driver(idtfc3_driver);