/* Copyright (c) 2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * This file contain content copied from Synopsis driver,
 * provided under the license below
 */
/* =========================================================================
 * The Synopsys DWC ETHER QOS Software Driver and documentation (hereinafter
 * "Software") is an unsupported proprietary work of Synopsys, Inc. unless
 * otherwise expressly agreed to in writing between Synopsys and you.
 *
 * The Software IS NOT an item of Licensed Software or Licensed Product under
 * any End User Software License Agreement or Agreement for Licensed Product
 * with Synopsys or any supplement thereto.  Permission is hereby granted,
 * free of charge, to any person obtaining a copy of this software annotated
 * with this license and the Software, to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject
 * to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THIS SOFTWARE IS BEING DISTRIBUTED BY SYNOPSYS SOLELY ON AN "AS IS" BASIS
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE HEREBY DISCLAIMED. IN NO EVENT SHALL SYNOPSYS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 * =========================================================================
 */

/*!@file: DWC_ETH_QOS_ptp.c
 * @brief: Driver functions.
 */
#include "DWC_ETH_QOS_yheader.h"
#include "DWC_ETH_QOS_yapphdr.h"
#ifdef CONFIG_PPS_OUTPUT
extern int ETH_PPSOUT_Config(struct DWC_ETH_QOS_prv_data *pdata, struct ifr_data_struct* req);
extern void DWC_ETH_QOS_pps_timer_init(struct ifr_data_struct* req);
#endif


/*!
 * \brief API to adjust the frequency of hardware clock.
 *
 * \details This function is used to adjust the frequency of the
 * hardware clock.
 *
 * \param[in] ptp – pointer to ptp_clock_info structure.
 * \param[in] delta – desired period change in parts per billion.
 *
 * \return int
 *
 * \retval 0 on success and -ve number on failure.
 */

static int DWC_ETH_QOS_adjust_freq(struct ptp_clock_info *ptp, s32 ppb)
{
	struct DWC_ETH_QOS_prv_data *pdata =
		container_of(ptp, struct DWC_ETH_QOS_prv_data, ptp_clock_ops);
	struct hw_if_struct *hw_if = &pdata->hw_if;
	unsigned long flags;
	u64 adj;
	u32 diff, addend;
	int neg_adj = 0;

	DBGPR_PTP("-->DWC_ETH_QOS_adjust_freq: %d\n", ppb);

	if (ppb < 0) {
		neg_adj = 1;
		ppb = -ppb;
	}

	addend = pdata->default_addend;
	adj = addend;
	adj *= ppb;
	/* div_u64 will divided the "adj" by "1000000000ULL"
	 * and return the quotient.
	 */
	diff = div_u64(adj, 1000000000ULL);
	addend = neg_adj ? (addend - diff) : (addend + diff);

	spin_lock_irqsave(&pdata->ptp_lock, flags);

	hw_if->config_addend(addend);

	spin_unlock_irqrestore(&pdata->ptp_lock, flags);

	DBGPR_PTP("<--DWC_ETH_QOS_adjust_freq\n");

	return 0;
}

/*!
 * \brief API to adjust the hardware time.
 *
 * \details This function is used to shift/adjust the time of the
 * hardware clock.
 *
 * \param[in] ptp – pointer to ptp_clock_info structure.
 * \param[in] delta – desired change in nanoseconds.
 *
 * \return int
 *
 * \retval 0 on success and -ve number on failure.
 */

static int DWC_ETH_QOS_adjust_time(struct ptp_clock_info *ptp, s64 delta)
{
	struct DWC_ETH_QOS_prv_data *pdata =
		container_of(ptp, struct DWC_ETH_QOS_prv_data, ptp_clock_ops);
	struct hw_if_struct *hw_if = &pdata->hw_if;
	unsigned long flags;
	u32 sec, nsec;
	u32 quotient, reminder;
	int neg_adj = 0;

	DBGPR_PTP("-->DWC_ETH_QOS_adjust_time: delta = %lld\n", delta);

	if (delta < 0) {
		neg_adj = 1;
		delta = -delta;
	}

	quotient = div_u64_rem(delta, 1000000000ULL, &reminder);
	sec = quotient;
	nsec = reminder;

	spin_lock_irqsave(&pdata->ptp_lock, flags);

	hw_if->adjust_systime(sec, nsec, neg_adj, pdata->one_nsec_accuracy);

	spin_unlock_irqrestore(&pdata->ptp_lock, flags);

	DBGPR_PTP("<--DWC_ETH_QOS_adjust_time\n");

	return 0;
}

/*!
 * \brief API to get the current time.
 *
 * \details This function is used to read the current time from the
 * hardware clock.
 *
 * \param[in] ptp – pointer to ptp_clock_info structure.
 * \param[in] ts – pointer to hold the time/result.
 *
 * \return int
 *
 * \retval 0 on success and -ve number on failure.
 */

static int DWC_ETH_QOS_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
	struct DWC_ETH_QOS_prv_data *pdata =
		container_of(ptp, struct DWC_ETH_QOS_prv_data, ptp_clock_ops);
	struct hw_if_struct *hw_if = &pdata->hw_if;
	u64 ns;
	u32 reminder;
	unsigned long flags;

	DBGPR_PTP("-->DWC_ETH_QOS_get_time\n");

	spin_lock_irqsave(&pdata->ptp_lock, flags);

	ns = hw_if->get_systime();

	spin_unlock_irqrestore(&pdata->ptp_lock, flags);

	ts->tv_sec = div_u64_rem(ns, 1000000000ULL, &reminder);
	ts->tv_nsec = reminder;

	DBGPR_PTP("<--DWC_ETH_QOS_get_time: ts->tv_sec = %ld,", ts->tv_sec);
	DBGPR_PTP("ts->tv_nsec = %ld\n", ts->tv_nsec);

	return 0;
}

/*!
 * \brief API to set the current time.
 *
 * \details This function is used to set the current time on the
 * hardware clock.
 *
 * \param[in] ptp – pointer to ptp_clock_info structure.
 * \param[in] ts – time value to set.
 *
 * \return int
 *
 * \retval 0 on success and -ve number on failure.
 */

static int DWC_ETH_QOS_set_time(struct ptp_clock_info *ptp,
				const struct timespec64 *ts)
{
	struct DWC_ETH_QOS_prv_data *pdata =
		container_of(ptp, struct DWC_ETH_QOS_prv_data, ptp_clock_ops);
	struct hw_if_struct *hw_if = &pdata->hw_if;
	unsigned long flags;

	DBGPR_PTP("-->DWC_ETH_QOS_set_time: ts->tv_sec = %ld,", ts->tv_sec);
	DBGPR_PTP("ts->tv_nsec = %ld\n", ts->tv_nsec);

	spin_lock_irqsave(&pdata->ptp_lock, flags);

	hw_if->init_systime(ts->tv_sec, ts->tv_nsec);

	spin_unlock_irqrestore(&pdata->ptp_lock, flags);

	DBGPR_PTP("<--DWC_ETH_QOS_set_time\n");

	return 0;
}

/*!
 * \brief API to enable/disable an ancillary feature.
 *
 * \details This function is used to enable or disable an ancillary
 * device feature like PPS, PEROUT and EXTTS.
 *
 * \param[in] ptp – pointer to ptp_clock_info structure.
 * \param[in] rq – desired resource to enable or disable.
 * \param[in] on – caller passes one to enable or zero to disable.
 *
 * \return int
 *
 * \retval 0 on success and -ve(EINVAL or EOPNOTSUPP) number on failure.
 */

static int DWC_ETH_QOS_enable(struct ptp_clock_info *ptp,
			      struct ptp_clock_request *rq, int on)
{
	return -EOPNOTSUPP;
}

/* structure describing a PTP hardware clock.
 */
static struct ptp_clock_info DWC_ETH_QOS_ptp_clock_ops = {
	.owner = THIS_MODULE,
	.name = "DWC_ETH_QOS_clk",
	.max_adj = DWC_ETH_QOS_SYSCLOCK,
	/* the max possible frequency adjustment, in parts per billion */
	.n_alarm = 0,	/* the number of programmable alarms */
	.n_ext_ts = 0,	/* the number of externel time stamp channels */
	.n_per_out = 0, /* the number of programmable periodic signals */
	.pps = 0,	/* indicates whether the clk supports a PPS callback */
	.adjfreq = DWC_ETH_QOS_adjust_freq,
	.adjtime = DWC_ETH_QOS_adjust_time,
	.gettime64 = DWC_ETH_QOS_get_time,
	.settime64 = DWC_ETH_QOS_set_time,
	.enable = DWC_ETH_QOS_enable,
};

/*!
 * \brief API to register ptp clock driver.
 *
 * \details This function is used to register the ptp clock
 * driver to kernel. It also does some housekeeping work.
 *
 * \param[in] pdata – pointer to private data structure.
 *
 * \return int
 *
 * \retval 0 on success and -ve number on failure.
 */

int DWC_ETH_QOS_ptp_init(struct DWC_ETH_QOS_prv_data *pdata)
{
	int ret = 0;
#ifdef CONFIG_PPS_OUTPUT
	struct ifr_data_struct req = {0};
	struct ETH_PPS_Config eth_pps_cfg = {0};
#endif

	DBGPR_PTP("-->DWC_ETH_QOS_ptp_init\n");

	if (!pdata->hw_feat.tsstssel) {
		ret = -1;
		pdata->ptp_clock = NULL;
		pr_alert("No PTP supports in HW\n"
			"Aborting PTP clock driver registration\n");
		goto no_hw_ptp;
	}

	DWC_ETH_QOS_enable_ptp_clk(&pdata->pdev->dev);

	spin_lock_init(&pdata->ptp_lock);

	pdata->ptp_clock_ops = DWC_ETH_QOS_ptp_clock_ops;

	pdata->ptp_clock = ptp_clock_register(&pdata->ptp_clock_ops,
						&pdata->pdev->dev);

	if (IS_ERR(pdata->ptp_clock)) {
		pdata->ptp_clock = NULL;
		pr_alert("ptp_clock_register() failed\n");
	} else {
		pr_alert("Added PTP HW clock successfully\n");
	}

#ifdef CONFIG_PPS_OUTPUT
	if (pdata->res_data->pps_lpass_conn_en) {
		/*Configuring PPS0 PPS output frequency to defualt 19.2 Mhz*/
		eth_pps_cfg.ppsout_ch = 0;
		eth_pps_cfg.ptpclk_freq = DWC_ETH_QOS_DEFAULT_PTP_CLOCK;
		eth_pps_cfg.ppsout_freq = DWC_ETH_QOS_DEFAULT_LPASS_PPS_FREQUENCY;
		eth_pps_cfg.ppsout_start = 1;
		eth_pps_cfg.ppsout_duty = 50;
		req.ptr = (void*)&eth_pps_cfg;

		DWC_ETH_QOS_pps_timer_init(&req);
		ret = ETH_PPSOUT_Config(pdata, &req);
	}
#endif

	DBGPR_PTP("<--DWC_ETH_QOS_ptp_init\n");

	return ret;

no_hw_ptp:
	return ret;
}

/*!
 * \brief API to unregister ptp clock driver.
 *
 * \details This function is used to remove/unregister the ptp
 * clock driver from the kernel.
 *
 * \param[in] pdata – pointer to private data structure.
 *
 * \return void
 */

void DWC_ETH_QOS_ptp_remove(struct DWC_ETH_QOS_prv_data *pdata)
{
	DBGPR_PTP("-->DWC_ETH_QOS_ptp_remove\n");

	if (pdata->ptp_clock) {
		ptp_clock_unregister(pdata->ptp_clock);
		pr_alert("Removed PTP HW clock successfully\n");
	}

	DWC_ETH_QOS_disable_ptp_clk(&pdata->pdev->dev);

	DBGPR_PTP("<--DWC_ETH_QOS_ptp_remove\n");
}
/*!
 * \brief API to find the PHC index.
 *
 * \details This function is used to find the PHC index from Linux subsystem
 *
 * \param[in] pdata ??? pointer to private data structure.
 *
 * \return void
 */

int DWC_ETH_QOS_phc_index(struct DWC_ETH_QOS_prv_data *pdata)
{
	DBGPR_PTP("Fetching PHC index \n");
	if (pdata->ptp_clock)
		return ptp_clock_index(pdata->ptp_clock);
	else
		return -1;
}