/* ============================================================================
* COPYRIGHT © 2015
*
* Toshiba America Electronic Components
*
* PROJECT:   NEUTRINO
*
* 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:
*
*
* EXAMPLE PROGRAMS ARE PROVIDED AS-IS WITH NO WARRANTY OF ANY KIND,
* EITHER EXPRESS OR IMPLIED.
*
* TOSHIBA ASSUMES NO LIABILITY FOR CUSTOMERS' PRODUCT DESIGN OR APPLICATIONS.
*
* THIS SOFTWARE IS PROVIDED AS-IS AND HAS NOT BEEN FULLY TESTED.  IT IS
* INTENDED FOR REFERENCE USE ONLY.
*
* TOSHIBA DISCLAIMS ALL EXPRESS AND IMPLIED WARRANTIES AND ALL LIABILITY OR
* ANY DAMAGES ASSOCIATED WITH YOUR USE OF THIS SOFTWARE.
*
* THIS SOFTWARE IS BEING DISTRIBUTED BY TOSHIBA 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 TOSHIBA 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.
*
* ========================================================================= */

/* =========================================================================
* 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.
* ========================================================================= */

/*! History:
 *      2-March-2016 : Initial
 */

/*!@file: DWC_ETH_QOS_ptp.c
 * @brief: Driver functions.
 */
#include "DWC_ETH_QOS_yheader.h"
#include <linux/ptp_clock_kernel.h>


/*!
 * \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, pdata);

	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, pdata);

	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 timespec *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(pdata);

	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_nsec = %ld\n", ts->tv_sec, 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 timespec *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_nsec = %ld\n", ts->tv_sec, ts->tv_nsec);

	spin_lock_irqsave(&pdata->ptp_lock, flags);

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

	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,
	.gettime = DWC_ETH_QOS_get_time,
	.settime = DWC_ETH_QOS_set_time,
	.enable = DWC_ETH_QOS_enable,
};

/*!
 * \brief Print the PTP clock time to the buffer.
 *
 * \details This function reads the PTP clock from the hardware and then print
 * it to the buffer that will be returned to user space.
 *
 * \param[in] dev - device pointer
 * \param[in] attr - sysfs attribute
 * \param[in] buf - buffer that will be returned to user space
 *
 * \return ssize_t
 *
 * \retval number of characters in the buffer when returned.
 */
static ssize_t DWC_ETH_QOS_ptp_clock_show(struct device *dev,
	struct device_attribute *attr, char *buf)
{
	struct net_device *ndev = pci_get_drvdata(to_pci_dev(dev));
	struct DWC_ETH_QOS_prv_data *pdata = netdev_priv(ndev);
	struct timespec ts;

	DWC_ETH_QOS_get_time(&pdata->ptp_clock_ops, &ts);

	return sprintf(buf, "%lld.%.9ld\n", (long long)ts.tv_sec, ts.tv_nsec);
}
static DEVICE_ATTR(ptp_clock, S_IRUSR, DWC_ETH_QOS_ptp_clock_show, NULL);

/*!
 * \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;

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

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

	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;
		NMSGPR_ALERT( "ptp_clock_register() failed\n");
	} else
		DBGPR_PTP( "Added PTP HW clock successfully\n");

	ret = device_create_file(&pdata->pdev->dev, &dev_attr_ptp_clock);

	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);
		NMSGPR_ALERT( "Removed PTP HW clock successfully\n");
	}

	device_remove_file(&pdata->pdev->dev, &dev_attr_ptp_clock);

	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)
{
	NDBGPR_L1("Fetching PHC index \n");
	if (pdata->ptp_clock)
		return ptp_clock_index(pdata->ptp_clock);
	else
		return -1;
}