ptp: Add a ptp clock driver for IDT 82P33 SMU.

The IDT 82P33 Synchronization Management Unit (SMU) family provides
tools to manage timing references, clock sources and
timing paths for IEEE 1588 / Precision Time Protocol (PTP) and
Synchronous Ethernet (SyncE) based clocks. The device supports up
to three independent timing paths that control: PTP clock synthesis;
SyncE clock generation; and general purpose frequency translation.
The device supports physical layer timing with Digital PLLs (DPLLs)
and it supports packet based timing with Digitally Controlled
Oscillators (DCOs). This patch adds support for ptp clock based on
the device.

Changes since v1:
 - As suggested by Richard Cochran:
   1. Replace _mask_bit_count with the existing hweight8
   2. Prefix all functions with idt82p33
   3. Fix white space issues in Kconfig and Makefile
   4. Remove forward declaration
   5. Use adjfine instead of adjfreq for better resolution

 - As suggested by David Miller:
   1. Replace CHAN_INIT macro with a static function
      idt82p33_channel_init
   2. Employ reverse christmas tree ordering for local
      variables
   3. Fix indentation problem by appropriate number of
      TAB then SPACE character
Signed-off-by: Min Li <min.li.xe@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ptp/Kconfig

@@ -115,6 +115,18 @@ config PTP_1588_CLOCK_KVM
 	  To compile this driver as a module, choose M here: the module
 	  will be called ptp_kvm.
 
+config PTP_1588_CLOCK_IDT82P33
+	tristate "IDT 82P33xxx PTP clock"
+	depends on PTP_1588_CLOCK && I2C
+	default n
+	help
+	  This driver adds support for using the IDT 82P33xxx as a PTP
+	  clock. This clock is only useful if your time stamping MAC
+	  is connected to the IDT chip.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called ptp_idt82p33.
+
 config PTP_1588_CLOCK_IDTCM
 	tristate "IDT CLOCKMATRIX as PTP clock"
 	depends on PTP_1588_CLOCK && I2C

drivers/ptp/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_PTP_1588_CLOCK_QORIQ)	+= ptp-qoriq.o
 ptp-qoriq-y				+= ptp_qoriq.o
 ptp-qoriq-$(CONFIG_DEBUG_FS)		+= ptp_qoriq_debugfs.o
 obj-$(CONFIG_PTP_1588_CLOCK_IDTCM)	+= ptp_clockmatrix.o
+obj-$(CONFIG_PTP_1588_CLOCK_IDT82P33)	+= ptp_idt82p33.o

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/i2c.h>
+#include <linux/module.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/timekeeping.h>
+#include <linux/bitops.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 Parameters */
+u32 sync_tod_timeout = SYNC_TOD_TIMEOUT_SEC;
+module_param(sync_tod_timeout, uint, 0);
+MODULE_PARM_DESC(sync_tod_timeout,
+"duration in second to keep SYNC_TOD on (set to 0 to keep it always on)");
+
+u32 phase_snap_threshold = SNAP_THRESHOLD_NS;
+module_param(phase_snap_threshold, uint, 0);
+MODULE_PARM_DESC(phase_snap_threshold,
+"threshold (150000ns by default) below which adjtime would ignore");
+
+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_xfer(struct idt82p33 *idt82p33,
+			 unsigned char regaddr,
+			 unsigned char *buf,
+			 unsigned int count,
+			 int write)
+{
+	struct i2c_client *client = idt82p33->client;
+	struct i2c_msg msg[2];
+	int cnt;
+
+	msg[0].addr = client->addr;
+	msg[0].flags = 0;
+	msg[0].len = 1;
+	msg[0].buf = &regaddr;
+
+	msg[1].addr = client->addr;
+	msg[1].flags = write ? 0 : I2C_M_RD;
+	msg[1].len = count;
+	msg[1].buf = buf;
+
+	cnt = i2c_transfer(client->adapter, msg, 2);
+	if (cnt < 0) {
+		dev_err(&client->dev, "i2c_transfer returned %d\n", cnt);
+		return cnt;
+	} else if (cnt != 2) {
+		dev_err(&client->dev,
+			"i2c_transfer sent only %d of %d messages\n", cnt, 2);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int idt82p33_page_offset(struct idt82p33 *idt82p33, unsigned char val)
+{
+	int err;
+
+	if (idt82p33->page_offset == val)
+		return 0;
+
+	err = idt82p33_xfer(idt82p33, PAGE_ADDR, &val, sizeof(val), 1);
+	if (err)
+		dev_err(&idt82p33->client->dev,
+			"failed to set page offset %d\n", val);
+	else
+		idt82p33->page_offset = val;
+
+	return err;
+}
+
+static int idt82p33_rdwr(struct idt82p33 *idt82p33, unsigned int regaddr,
+			 unsigned char *buf, unsigned int count, bool write)
+{
+	u8 offset, page;
+	int err;
+
+	page = _PAGE(regaddr);
+	offset = _OFFSET(regaddr);
+
+	err = idt82p33_page_offset(idt82p33, page);
+	if (err)
+		goto out;
+
+	err = idt82p33_xfer(idt82p33, offset, buf, count, write);
+out:
+	return err;
+}
+
+static int idt82p33_read(struct idt82p33 *idt82p33, unsigned int regaddr,
+			unsigned char *buf, unsigned int count)
+{
+	return idt82p33_rdwr(idt82p33, regaddr, buf, count, false);
+}
+
+static int idt82p33_write(struct idt82p33 *idt82p33, unsigned int regaddr,
+			unsigned char *buf, unsigned int count)
+{
+	return idt82p33_rdwr(idt82p33, regaddr, buf, count, true);
+}
+
+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 = dpll_mode;
+
+	return 0;
+}
+
+static int _idt82p33_gettime(struct idt82p33_channel *channel,
+			     struct timespec64 *ts)
+{
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+	u8 buf[TOD_BYTE_COUNT];
+	u8 trigger;
+	int err;
+
+	trigger = TOD_TRIGGER(HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
+			      HW_TOD_RD_TRIG_SEL_LSB_TOD_STS);
+
+
+	err = idt82p33_write(idt82p33, channel->dpll_tod_trigger,
+			     &trigger, sizeof(trigger));
+
+	if (err)
+		return err;
+
+	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;
+
+	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;
+	unsigned char trigger;
+	int err;
+	u8 i;
+
+	trigger = TOD_TRIGGER(HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
+			      HW_TOD_RD_TRIG_SEL_LSB_TOD_STS);
+
+	err = idt82p33_write(idt82p33, channel->dpll_tod_trigger,
+			&trigger, sizeof(trigger));
+
+	if (err)
+		return err;
+
+	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(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_adjfine(struct idt82p33_channel *channel, long scaled_ppm)
+{
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+	unsigned char buf[5] = {0};
+	int neg_adj = 0;
+	int err, i;
+	s64 fcw;
+
+	if (scaled_ppm == channel->current_freq_ppb)
+		return 0;
+
+	/*
+	 * Frequency Control Word unit is: 1.68 * 10^-10 ppm
+	 *
+	 * adjfreq:
+	 *       ppb * 10^9
+	 * FCW = ----------
+	 *          168
+	 *
+	 * adjfine:
+	 *       scaled_ppm * 5^12
+	 * FCW = -------------
+	 *         168 * 2^4
+	 */
+	if (scaled_ppm < 0) {
+		neg_adj = 1;
+		scaled_ppm = -scaled_ppm;
+	}
+
+	fcw = scaled_ppm * 244140625ULL;
+	fcw = div_u64(fcw, 2688);
+
+	if (neg_adj)
+		fcw = -fcw;
+
+	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));
+
+	if (err == 0)
+		channel->current_freq_ppb = scaled_ppm;
+
+	return err;
+}
+
+static int idt82p33_measure_one_byte_write_overhead(
+		struct idt82p33_channel *channel, s64 *overhead_ns)
+{
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+	ktime_t start, stop;
+	s64 total_ns;
+	u8 trigger;
+	int err;
+	u8 i;
+
+	total_ns = 0;
+	*overhead_ns = 0;
+	trigger = TOD_TRIGGER(HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
+			      HW_TOD_RD_TRIG_SEL_LSB_TOD_STS);
+
+	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_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;
+	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)
+		return err;
+
+	err = idt82p33_measure_one_byte_write_overhead(channel,
+						       &one_byte_write_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);
+
+	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->client->dev,
+				"Invalid PLL mask 0x%hhx\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->client->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->client->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;
+
+	if (enable == channel->sync_tod_on) {
+		if (enable && sync_tod_timeout) {
+			mod_delayed_work(system_wq, &channel->sync_tod_work,
+					 sync_tod_timeout * HZ);
+		}
+		return 0;
+	}
+
+	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;
+
+	err = idt82p33_write(idt82p33, channel->dpll_sync_cnfg,
+			     &sync_cnfg, sizeof(sync_cnfg));
+	if (err)
+		return err;
+
+	channel->sync_tod_on = enable;
+
+	if (enable && sync_tod_timeout) {
+		mod_delayed_work(system_wq, &channel->sync_tod_work,
+				 sync_tod_timeout * HZ);
+	}
+
+	return 0;
+}
+
+static void idt82p33_sync_tod_work_handler(struct work_struct *work)
+{
+	struct idt82p33_channel *channel =
+		container_of(work, struct idt82p33_channel, sync_tod_work.work);
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+
+	mutex_lock(&idt82p33->reg_lock);
+
+	(void)idt82p33_sync_tod(channel, false);
+
+	mutex_unlock(&idt82p33->reg_lock);
+}
+
+static int idt82p33_pps_enable(struct idt82p33_channel *channel, bool enable)
+{
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+	u8 mask, outn, val;
+	int err;
+
+	mask = channel->output_mask;
+	outn = 0;
+
+	while (mask) {
+		if (mask & 0x1) {
+			err = idt82p33_read(idt82p33, OUT_MUX_CNFG(outn),
+					    &val, sizeof(val));
+			if (err)
+				return err;
+
+			if (enable)
+				val &= ~SQUELCH_ENABLE;
+			else
+				val |= SQUELCH_ENABLE;
+
+			err = idt82p33_write(idt82p33, OUT_MUX_CNFG(outn),
+					     &val, sizeof(val));
+
+			if (err)
+				return err;
+		}
+		mask >>= 0x1;
+		outn++;
+	}
+
+	return 0;
+}
+
+static int idt82p33_enable_tod(struct idt82p33_channel *channel)
+{
+	struct idt82p33 *idt82p33 = channel->idt82p33;
+	struct timespec64 ts = {0, 0};
+	int err;
+	u8 val;
+
+	val = 0;
+	err = idt82p33_write(idt82p33, channel->dpll_input_mode_cnfg,
+			     &val, sizeof(val));
+	if (err)
+		return err;
+
+	err = idt82p33_pps_enable(channel, false);
+
+	if (err)
+		return err;
+
+	err = idt82p33_measure_tod_write_overhead(channel);
+
+	if (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];
+
+		if (channel->ptp_clock) {
+			ptp_clock_unregister(channel->ptp_clock);
+			cancel_delayed_work_sync(&channel->sync_tod_work);
+		}
+	}
+}
+
+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;
+
+	err = -EOPNOTSUPP;
+
+	mutex_lock(&idt82p33->reg_lock);
+
+	if (rq->type == PTP_CLK_REQ_PEROUT) {
+		if (!on)
+			err = idt82p33_pps_enable(channel, false);
+
+		/* 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_pps_enable(channel, true);
+	}
+
+	mutex_unlock(&idt82p33->reg_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;
+
+	mutex_lock(&idt82p33->reg_lock);
+	err = _idt82p33_adjfine(channel, scaled_ppm);
+	mutex_unlock(&idt82p33->reg_lock);
+
+	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;
+
+	mutex_lock(&idt82p33->reg_lock);
+
+	if (abs(delta_ns) < phase_snap_threshold) {
+		mutex_unlock(&idt82p33->reg_lock);
+		return 0;
+	}
+
+	err = _idt82p33_adjtime(channel, delta_ns);
+
+	if (err) {
+		mutex_unlock(&idt82p33->reg_lock);
+		return err;
+	}
+
+	err = idt82p33_sync_tod(channel, true);
+
+	mutex_unlock(&idt82p33->reg_lock);
+
+	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->reg_lock);
+	err = _idt82p33_gettime(channel, ts);
+	mutex_unlock(&idt82p33->reg_lock);
+
+	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->reg_lock);
+	err = _idt82p33_settime(channel, ts);
+	mutex_unlock(&idt82p33->reg_lock);
+
+	return err;
+}
+
+static int idt82p33_channel_init(struct idt82p33_channel *channel, int 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;
+	}
+
+	INIT_DELAYED_WORK(&channel->sync_tod_work,
+			  idt82p33_sync_tod_work_handler);
+	channel->sync_tod_on = false;
+	channel->current_freq_ppb = 0;
+
+	return 0;
+}
+
+static void idt82p33_caps_init(struct ptp_clock_info *caps)
+{
+	caps->owner = THIS_MODULE;
+	caps->max_adj = 92000;
+	caps->adjfine = idt82p33_adjfine;
+	caps->adjtime = idt82p33_adjtime;
+	caps->gettime64 = idt82p33_gettime;
+	caps->settime64 = idt82p33_settime;
+	caps->enable = idt82p33_enable;
+}
+
+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(channel, index);
+	if (err)
+		return err;
+
+	channel->idt82p33 = idt82p33;
+
+	idt82p33_caps_init(&channel->caps);
+	snprintf(channel->caps.name, sizeof(channel->caps.name),
+		 "IDT 82P33 PLL%u", index);
+	channel->caps.n_per_out = hweight8(channel->output_mask);
+
+	err = idt82p33_dpll_set_mode(channel, PLL_MODE_DCO);
+	if (err)
+		return err;
+
+	err = idt82p33_enable_tod(channel);
+	if (err)
+		return err;
+
+	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;
+
+	dev_info(&idt82p33->client->dev, "PLL%d registered as ptp%d\n",
+		 index, channel->ptp_clock->index);
+
+	return 0;
+}
+
+static int idt82p33_load_firmware(struct idt82p33 *idt82p33)
+{
+	const struct firmware *fw;
+	struct idt82p33_fwrc *rec;
+	u8 loaddr, page, val;
+	int err;
+	s32 len;
+
+	dev_dbg(&idt82p33->client->dev,
+		"requesting firmware '%s'\n", FW_FILENAME);
+
+	err = request_firmware(&fw, FW_FILENAME, &idt82p33->client->dev);
+
+	if (err)
+		return err;
+
+	dev_dbg(&idt82p33->client->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->client->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) {
+			/* maximum 8 pages  */
+			if (page >= PAGE_NUM)
+				continue;
+
+			/* Page size 128, last 4 bytes of page skipped */
+			if (((loaddr > 0x7b) && (loaddr <= 0x7f))
+			     || ((loaddr > 0xfb) && (loaddr <= 0xff)))
+				continue;
+
+			err = idt82p33_write(idt82p33, _ADDR(page, loaddr),
+					     &val, sizeof(val));
+		}
+
+		if (err)
+			goto out;
+	}
+
+	idt82p33_display_masks(idt82p33);
+out:
+	release_firmware(fw);
+	return err;
+}
+
+
+static int idt82p33_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	struct idt82p33 *idt82p33;
+	int err;
+	u8 i;
+
+	(void)id;
+
+	idt82p33 = devm_kzalloc(&client->dev,
+				sizeof(struct idt82p33), GFP_KERNEL);
+	if (!idt82p33)
+		return -ENOMEM;
+
+	mutex_init(&idt82p33->reg_lock);
+
+	idt82p33->client = client;
+	idt82p33->page_offset = 0xff;
+	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;
+
+	mutex_lock(&idt82p33->reg_lock);
+
+	err = idt82p33_load_firmware(idt82p33);
+
+	if (err)
+		dev_warn(&idt82p33->client->dev,
+			 "loading firmware failed with %d\n", err);
+
+	if (idt82p33->pll_mask) {
+		for (i = 0; i < MAX_PHC_PLL; i++) {
+			if (idt82p33->pll_mask & (1 << i)) {
+				err = idt82p33_enable_channel(idt82p33, i);
+				if (err)
+					break;
+			}
+		}
+	} else {
+		dev_err(&idt82p33->client->dev,
+			"no PLLs flagged as PHCs, nothing to do\n");
+		err = -ENODEV;
+	}
+
+	mutex_unlock(&idt82p33->reg_lock);
+
+	if (err) {
+		idt82p33_ptp_clock_unregister_all(idt82p33);
+		return err;
+	}
+
+	i2c_set_clientdata(client, idt82p33);
+
+	return 0;
+}
+
+static int idt82p33_remove(struct i2c_client *client)
+{
+	struct idt82p33 *idt82p33 = i2c_get_clientdata(client);
+
+	idt82p33_ptp_clock_unregister_all(idt82p33);
+	mutex_destroy(&idt82p33->reg_lock);
+
+	return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id idt82p33_dt_id[] = {
+	{ .compatible = "idt,82p33810" },
+	{ .compatible = "idt,82p33813" },
+	{ .compatible = "idt,82p33814" },
+	{ .compatible = "idt,82p33831" },
+	{ .compatible = "idt,82p33910" },
+	{ .compatible = "idt,82p33913" },
+	{ .compatible = "idt,82p33914" },
+	{ .compatible = "idt,82p33931" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, idt82p33_dt_id);
+#endif
+
+static const struct i2c_device_id idt82p33_i2c_id[] = {
+	{ "idt82p33810", },
+	{ "idt82p33813", },
+	{ "idt82p33814", },
+	{ "idt82p33831", },
+	{ "idt82p33910", },
+	{ "idt82p33913", },
+	{ "idt82p33914", },
+	{ "idt82p33931", },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, idt82p33_i2c_id);
+
+static struct i2c_driver idt82p33_driver = {
+	.driver = {
+		.of_match_table	= of_match_ptr(idt82p33_dt_id),
+		.name		= "idt82p33",
+	},
+	.probe		= idt82p33_probe,
+	.remove		= idt82p33_remove,
+	.id_table	= idt82p33_i2c_id,
+};
+
+module_i2c_driver(idt82p33_driver);

drivers/ptp/ptp_idt82p33.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * PTP hardware clock driver for the IDT 82P33XXX family of clocks.
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#ifndef PTP_IDT82P33_H
+#define PTP_IDT82P33_H
+
+#include <linux/ktime.h>
+#include <linux/workqueue.h>
+
+
+/* Register Map - AN888_SMUforIEEE_SynchEther_82P33xxx_RevH.pdf */
+#define PAGE_NUM (8)
+#define _ADDR(page, offset) (((page) << 0x7) | ((offset) & 0x7f))
+#define _PAGE(addr) (((addr) >> 0x7) & 0x7)
+#define _OFFSET(addr)  ((addr) & 0x7f)
+
+#define DPLL1_TOD_CNFG 0x134
+#define DPLL2_TOD_CNFG 0x1B4
+
+#define DPLL1_TOD_STS 0x10B
+#define DPLL2_TOD_STS 0x18B
+
+#define DPLL1_TOD_TRIGGER 0x115
+#define DPLL2_TOD_TRIGGER 0x195
+
+#define DPLL1_OPERATING_MODE_CNFG 0x120
+#define DPLL2_OPERATING_MODE_CNFG 0x1A0
+
+#define DPLL1_HOLDOVER_FREQ_CNFG 0x12C
+#define DPLL2_HOLDOVER_FREQ_CNFG 0x1AC
+
+#define DPLL1_PHASE_OFFSET_CNFG 0x143
+#define DPLL2_PHASE_OFFSET_CNFG 0x1C3
+
+#define DPLL1_SYNC_EDGE_CNFG 0X140
+#define DPLL2_SYNC_EDGE_CNFG 0X1C0
+
+#define DPLL1_INPUT_MODE_CNFG 0X116
+#define DPLL2_INPUT_MODE_CNFG 0X196
+
+#define OUT_MUX_CNFG(outn) _ADDR(0x6, (0xC * (outn)))
+
+#define PAGE_ADDR 0x7F
+/* Register Map end */
+
+/* Register definitions - AN888_SMUforIEEE_SynchEther_82P33xxx_RevH.pdf*/
+#define TOD_TRIGGER(wr_trig, rd_trig) ((wr_trig & 0xf) << 4 | (rd_trig & 0xf))
+#define SYNC_TOD BIT(1)
+#define PH_OFFSET_EN BIT(7)
+#define SQUELCH_ENABLE BIT(5)
+
+/* Bit definitions for the DPLL_MODE register */
+#define PLL_MODE_SHIFT                    (0)
+#define PLL_MODE_MASK                     (0x1F)
+
+enum pll_mode {
+	PLL_MODE_MIN = 0,
+	PLL_MODE_AUTOMATIC = PLL_MODE_MIN,
+	PLL_MODE_FORCE_FREERUN = 1,
+	PLL_MODE_FORCE_HOLDOVER = 2,
+	PLL_MODE_FORCE_LOCKED = 4,
+	PLL_MODE_FORCE_PRE_LOCKED2 = 5,
+	PLL_MODE_FORCE_PRE_LOCKED = 6,
+	PLL_MODE_FORCE_LOST_PHASE = 7,
+	PLL_MODE_DCO = 10,
+	PLL_MODE_WPH = 18,
+	PLL_MODE_MAX = PLL_MODE_WPH,
+};
+
+enum hw_tod_trig_sel {
+	HW_TOD_TRIG_SEL_MIN = 0,
+	HW_TOD_TRIG_SEL_NO_WRITE = HW_TOD_TRIG_SEL_MIN,
+	HW_TOD_TRIG_SEL_SYNC_SEL = 1,
+	HW_TOD_TRIG_SEL_IN12 = 2,
+	HW_TOD_TRIG_SEL_IN13 = 3,
+	HW_TOD_TRIG_SEL_IN14 = 4,
+	HW_TOD_TRIG_SEL_TOD_PPS = 5,
+	HW_TOD_TRIG_SEL_TIMER_INTERVAL = 6,
+	HW_TOD_TRIG_SEL_MSB_PHASE_OFFSET_CNFG = 7,
+	HW_TOD_TRIG_SEL_MSB_HOLDOVER_FREQ_CNFG = 8,
+	HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG = 9,
+	HW_TOD_RD_TRIG_SEL_LSB_TOD_STS = HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
+	WR_TRIG_SEL_MAX = HW_TOD_WR_TRIG_SEL_MSB_TOD_CNFG,
+};
+
+/* Register bit definitions end */
+#define FW_FILENAME	"idt82p33xxx.bin"
+#define MAX_PHC_PLL (2)
+#define TOD_BYTE_COUNT (10)
+#define MAX_MEASURMENT_COUNT (5)
+#define SNAP_THRESHOLD_NS (150000)
+#define SYNC_TOD_TIMEOUT_SEC (5)
+
+#define PLLMASK_ADDR_HI	0xFF
+#define PLLMASK_ADDR_LO	0xA5
+
+#define PLL0_OUTMASK_ADDR_HI	0xFF
+#define PLL0_OUTMASK_ADDR_LO	0xB0
+
+#define PLL1_OUTMASK_ADDR_HI	0xFF
+#define PLL1_OUTMASK_ADDR_LO	0xB2
+
+#define PLL2_OUTMASK_ADDR_HI	0xFF
+#define PLL2_OUTMASK_ADDR_LO	0xB4
+
+#define PLL3_OUTMASK_ADDR_HI	0xFF
+#define PLL3_OUTMASK_ADDR_LO	0xB6
+
+#define DEFAULT_PLL_MASK	(0x01)
+#define DEFAULT_OUTPUT_MASK_PLL0	(0xc0)
+#define DEFAULT_OUTPUT_MASK_PLL1	DEFAULT_OUTPUT_MASK_PLL0
+
+/* PTP Hardware Clock interface */
+struct idt82p33_channel {
+	struct ptp_clock_info	caps;
+	struct ptp_clock	*ptp_clock;
+	struct idt82p33	*idt82p33;
+	enum pll_mode	pll_mode;
+	/* task to turn off SYNC_TOD bit after pps sync */
+	struct delayed_work	sync_tod_work;
+	bool			sync_tod_on;
+	s32			current_freq_ppb;
+	u8			output_mask;
+	u16			dpll_tod_cnfg;
+	u16			dpll_tod_trigger;
+	u16			dpll_tod_sts;
+	u16			dpll_mode_cnfg;
+	u16			dpll_freq_cnfg;
+	u16			dpll_phase_cnfg;
+	u16			dpll_sync_cnfg;
+	u16			dpll_input_mode_cnfg;
+};
+
+struct idt82p33 {
+	struct idt82p33_channel channel[MAX_PHC_PLL];
+	struct i2c_client	*client;
+	u8	page_offset;
+	u8	pll_mask;
+	ktime_t start_time;
+	int calculate_overhead_flag;
+	s64 tod_write_overhead_ns;
+	/* Protects I2C read/modify/write registers from concurrent access */
+	struct mutex	reg_lock;
+};
+
+/* firmware interface */
+struct idt82p33_fwrc {
+	u8 hiaddr;
+	u8 loaddr;
+	u8 value;
+	u8 reserved;
+} __packed;
+
+/**
+ * @brief Maximum absolute value for write phase offset in femtoseconds
+ */
+#define WRITE_PHASE_OFFSET_LIMIT (20000052084ll)
+
+/** @brief Phase offset resolution
+ *
+ *  DPLL phase offset = 10^15 fs / ( System Clock  * 2^13)
+ *                    = 10^15 fs / ( 1638400000 * 2^23)
+ *                    = 74.5058059692382 fs
+ */
+#define IDT_T0DPLL_PHASE_RESOL 74506
+
+
+#endif /* PTP_IDT82P33_H */