// SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-3-Clause)
/*
 * Copyright (c) 2014-2025, Advanced Micro Devices, Inc.
 * Copyright (c) 2014, Synopsys, Inc.
 * All rights reserved
 */

#include <linux/clk.h>
#include <linux/clocksource.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/net_tstamp.h>

#include "xgbe.h"
#include "xgbe-common.h"

static u64 xgbe_cc_read(const struct cyclecounter *cc)
{
	struct xgbe_prv_data *pdata = container_of(cc,
						   struct xgbe_prv_data,
						   tstamp_cc);
	u64 nsec;

	nsec = pdata->hw_if.get_tstamp_time(pdata);

	return nsec;
}

static int xgbe_adjfine(struct ptp_clock_info *info, long scaled_ppm)
{
	struct xgbe_prv_data *pdata = container_of(info,
						   struct xgbe_prv_data,
						   ptp_clock_info);
	unsigned long flags;
	u64 addend;

	addend = adjust_by_scaled_ppm(pdata->tstamp_addend, scaled_ppm);

	spin_lock_irqsave(&pdata->tstamp_lock, flags);

	pdata->hw_if.update_tstamp_addend(pdata, addend);

	spin_unlock_irqrestore(&pdata->tstamp_lock, flags);

	return 0;
}

static int xgbe_adjtime(struct ptp_clock_info *info, s64 delta)
{
	struct xgbe_prv_data *pdata = container_of(info,
						   struct xgbe_prv_data,
						   ptp_clock_info);
	unsigned long flags;

	spin_lock_irqsave(&pdata->tstamp_lock, flags);
	timecounter_adjtime(&pdata->tstamp_tc, delta);
	spin_unlock_irqrestore(&pdata->tstamp_lock, flags);

	return 0;
}

static int xgbe_gettime(struct ptp_clock_info *info, struct timespec64 *ts)
{
	struct xgbe_prv_data *pdata = container_of(info,
						   struct xgbe_prv_data,
						   ptp_clock_info);
	unsigned long flags;
	u64 nsec;

	spin_lock_irqsave(&pdata->tstamp_lock, flags);

	nsec = timecounter_read(&pdata->tstamp_tc);

	spin_unlock_irqrestore(&pdata->tstamp_lock, flags);

	*ts = ns_to_timespec64(nsec);

	return 0;
}

static int xgbe_settime(struct ptp_clock_info *info,
			const struct timespec64 *ts)
{
	struct xgbe_prv_data *pdata = container_of(info,
						   struct xgbe_prv_data,
						   ptp_clock_info);
	unsigned long flags;
	u64 nsec;

	nsec = timespec64_to_ns(ts);

	spin_lock_irqsave(&pdata->tstamp_lock, flags);

	timecounter_init(&pdata->tstamp_tc, &pdata->tstamp_cc, nsec);

	spin_unlock_irqrestore(&pdata->tstamp_lock, flags);

	return 0;
}

static int xgbe_enable(struct ptp_clock_info *info,
		       struct ptp_clock_request *request, int on)
{
	return -EOPNOTSUPP;
}

void xgbe_ptp_register(struct xgbe_prv_data *pdata)
{
	struct ptp_clock_info *info = &pdata->ptp_clock_info;
	struct ptp_clock *clock;
	struct cyclecounter *cc = &pdata->tstamp_cc;
	u64 dividend;

	snprintf(info->name, sizeof(info->name), "%s",
		 netdev_name(pdata->netdev));
	info->owner = THIS_MODULE;
	info->max_adj = pdata->ptpclk_rate;
	info->adjfine = xgbe_adjfine;
	info->adjtime = xgbe_adjtime;
	info->gettime64 = xgbe_gettime;
	info->settime64 = xgbe_settime;
	info->enable = xgbe_enable;

	clock = ptp_clock_register(info, pdata->dev);
	if (IS_ERR(clock)) {
		dev_err(pdata->dev, "ptp_clock_register failed\n");
		return;
	}

	pdata->ptp_clock = clock;

	/* Calculate the addend:
	 *   addend = 2^32 / (PTP ref clock / 50Mhz)
	 *          = (2^32 * 50Mhz) / PTP ref clock
	 */
	dividend = 50000000;
	dividend <<= 32;
	pdata->tstamp_addend = div_u64(dividend, pdata->ptpclk_rate);

	/* Setup the timecounter */
	cc->read = xgbe_cc_read;
	cc->mask = CLOCKSOURCE_MASK(64);
	cc->mult = 1;
	cc->shift = 0;

	timecounter_init(&pdata->tstamp_tc, &pdata->tstamp_cc,
			 ktime_to_ns(ktime_get_real()));

	/* Disable all timestamping to start */
	XGMAC_IOWRITE(pdata, MAC_TSCR, 0);
	pdata->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
	pdata->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;
}

void xgbe_ptp_unregister(struct xgbe_prv_data *pdata)
{
	if (pdata->ptp_clock)
		ptp_clock_unregister(pdata->ptp_clock);
}