// SPDX-License-Identifier: GPL-2.0+

#include <linux/ptp_classify.h>

#include "lan966x_main.h"

#define LAN966X_MAX_PTP_ID	512

/* Represents 1ppm adjustment in 2^59 format with 6.037735849ns as reference
 * The value is calculated as following: (1/1000000)/((2^-59)/6.037735849)
 */
#define LAN966X_1PPM_FORMAT		3480517749723LL

/* Represents 1ppb adjustment in 2^29 format with 6.037735849ns as reference
 * The value is calculated as following: (1/1000000000)/((2^59)/6.037735849)
 */
#define LAN966X_1PPB_FORMAT		3480517749LL

#define TOD_ACC_PIN		0x5

enum {
	PTP_PIN_ACTION_IDLE = 0,
	PTP_PIN_ACTION_LOAD,
	PTP_PIN_ACTION_SAVE,
	PTP_PIN_ACTION_CLOCK,
	PTP_PIN_ACTION_DELTA,
	PTP_PIN_ACTION_TOD
};

static u64 lan966x_ptp_get_nominal_value(void)
{
	/* This is the default value that for each system clock, the time of day
	 * is increased. It has the format 5.59 nanosecond.
	 */
	return 0x304d4873ecade305;
}

int lan966x_ptp_hwtstamp_set(struct lan966x_port *port, struct ifreq *ifr)
{
	struct lan966x *lan966x = port->lan966x;
	struct hwtstamp_config cfg;
	struct lan966x_phc *phc;

	/* For now don't allow to run ptp on ports that are part of a bridge,
	 * because in case of transparent clock the HW will still forward the
	 * frames, so there would be duplicate frames
	 */
	if (lan966x->bridge_mask & BIT(port->chip_port))
		return -EINVAL;

	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
		return -EFAULT;

	switch (cfg.tx_type) {
	case HWTSTAMP_TX_ON:
		port->ptp_cmd = IFH_REW_OP_TWO_STEP_PTP;
		break;
	case HWTSTAMP_TX_ONESTEP_SYNC:
		port->ptp_cmd = IFH_REW_OP_ONE_STEP_PTP;
		break;
	case HWTSTAMP_TX_OFF:
		port->ptp_cmd = IFH_REW_OP_NOOP;
		break;
	default:
		return -ERANGE;
	}

	switch (cfg.rx_filter) {
	case HWTSTAMP_FILTER_NONE:
		break;
	case HWTSTAMP_FILTER_ALL:
	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
	case HWTSTAMP_FILTER_PTP_V2_EVENT:
	case HWTSTAMP_FILTER_PTP_V2_SYNC:
	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
	case HWTSTAMP_FILTER_NTP_ALL:
		cfg.rx_filter = HWTSTAMP_FILTER_ALL;
		break;
	default:
		return -ERANGE;
	}

	/* Commit back the result & save it */
	mutex_lock(&lan966x->ptp_lock);
	phc = &lan966x->phc[LAN966X_PHC_PORT];
	memcpy(&phc->hwtstamp_config, &cfg, sizeof(cfg));
	mutex_unlock(&lan966x->ptp_lock);

	return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
}

int lan966x_ptp_hwtstamp_get(struct lan966x_port *port, struct ifreq *ifr)
{
	struct lan966x *lan966x = port->lan966x;
	struct lan966x_phc *phc;

	phc = &lan966x->phc[LAN966X_PHC_PORT];
	return copy_to_user(ifr->ifr_data, &phc->hwtstamp_config,
			    sizeof(phc->hwtstamp_config)) ? -EFAULT : 0;
}

static int lan966x_ptp_classify(struct lan966x_port *port, struct sk_buff *skb)
{
	struct ptp_header *header;
	u8 msgtype;
	int type;

	if (port->ptp_cmd == IFH_REW_OP_NOOP)
		return IFH_REW_OP_NOOP;

	type = ptp_classify_raw(skb);
	if (type == PTP_CLASS_NONE)
		return IFH_REW_OP_NOOP;

	header = ptp_parse_header(skb, type);
	if (!header)
		return IFH_REW_OP_NOOP;

	if (port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
		return IFH_REW_OP_TWO_STEP_PTP;

	/* If it is sync and run 1 step then set the correct operation,
	 * otherwise run as 2 step
	 */
	msgtype = ptp_get_msgtype(header, type);
	if ((msgtype & 0xf) == 0)
		return IFH_REW_OP_ONE_STEP_PTP;

	return IFH_REW_OP_TWO_STEP_PTP;
}

static void lan966x_ptp_txtstamp_old_release(struct lan966x_port *port)
{
	struct sk_buff *skb, *skb_tmp;
	unsigned long flags;

	spin_lock_irqsave(&port->tx_skbs.lock, flags);
	skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
		if time_after(LAN966X_SKB_CB(skb)->jiffies + LAN966X_PTP_TIMEOUT,
			      jiffies)
			break;

		__skb_unlink(skb, &port->tx_skbs);
		dev_kfree_skb_any(skb);
	}
	spin_unlock_irqrestore(&port->tx_skbs.lock, flags);
}

int lan966x_ptp_txtstamp_request(struct lan966x_port *port,
				 struct sk_buff *skb)
{
	struct lan966x *lan966x = port->lan966x;
	unsigned long flags;
	u8 rew_op;

	rew_op = lan966x_ptp_classify(port, skb);
	LAN966X_SKB_CB(skb)->rew_op = rew_op;

	if (rew_op != IFH_REW_OP_TWO_STEP_PTP)
		return 0;

	lan966x_ptp_txtstamp_old_release(port);

	spin_lock_irqsave(&lan966x->ptp_ts_id_lock, flags);
	if (lan966x->ptp_skbs == LAN966X_MAX_PTP_ID) {
		spin_unlock_irqrestore(&lan966x->ptp_ts_id_lock, flags);
		return -EBUSY;
	}

	skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;

	skb_queue_tail(&port->tx_skbs, skb);
	LAN966X_SKB_CB(skb)->ts_id = port->ts_id;
	LAN966X_SKB_CB(skb)->jiffies = jiffies;

	lan966x->ptp_skbs++;
	port->ts_id++;
	if (port->ts_id == LAN966X_MAX_PTP_ID)
		port->ts_id = 0;

	spin_unlock_irqrestore(&lan966x->ptp_ts_id_lock, flags);

	return 0;
}

void lan966x_ptp_txtstamp_release(struct lan966x_port *port,
				  struct sk_buff *skb)
{
	struct lan966x *lan966x = port->lan966x;
	unsigned long flags;

	spin_lock_irqsave(&lan966x->ptp_ts_id_lock, flags);
	port->ts_id--;
	lan966x->ptp_skbs--;
	skb_unlink(skb, &port->tx_skbs);
	spin_unlock_irqrestore(&lan966x->ptp_ts_id_lock, flags);
}

static void lan966x_get_hwtimestamp(struct lan966x *lan966x,
				    struct timespec64 *ts,
				    u32 nsec)
{
	/* Read current PTP time to get seconds */
	unsigned long flags;
	u32 curr_nsec;

	spin_lock_irqsave(&lan966x->ptp_clock_lock, flags);

	lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_SAVE) |
		PTP_PIN_CFG_PIN_DOM_SET(LAN966X_PHC_PORT) |
		PTP_PIN_CFG_PIN_SYNC_SET(0),
		PTP_PIN_CFG_PIN_ACTION |
		PTP_PIN_CFG_PIN_DOM |
		PTP_PIN_CFG_PIN_SYNC,
		lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

	ts->tv_sec = lan_rd(lan966x, PTP_TOD_SEC_LSB(TOD_ACC_PIN));
	curr_nsec = lan_rd(lan966x, PTP_TOD_NSEC(TOD_ACC_PIN));

	ts->tv_nsec = nsec;

	/* Sec has incremented since the ts was registered */
	if (curr_nsec < nsec)
		ts->tv_sec--;

	spin_unlock_irqrestore(&lan966x->ptp_clock_lock, flags);
}

irqreturn_t lan966x_ptp_irq_handler(int irq, void *args)
{
	int budget = LAN966X_MAX_PTP_ID;
	struct lan966x *lan966x = args;

	while (budget--) {
		struct sk_buff *skb, *skb_tmp, *skb_match = NULL;
		struct skb_shared_hwtstamps shhwtstamps;
		struct lan966x_port *port;
		struct timespec64 ts;
		unsigned long flags;
		u32 val, id, txport;
		u32 delay;

		val = lan_rd(lan966x, PTP_TWOSTEP_CTRL);

		/* Check if a timestamp can be retrieved */
		if (!(val & PTP_TWOSTEP_CTRL_VLD))
			break;

		WARN_ON(val & PTP_TWOSTEP_CTRL_OVFL);

		if (!(val & PTP_TWOSTEP_CTRL_STAMP_TX))
			continue;

		/* Retrieve the ts Tx port */
		txport = PTP_TWOSTEP_CTRL_STAMP_PORT_GET(val);

		/* Retrieve its associated skb */
		port = lan966x->ports[txport];

		/* Retrieve the delay */
		delay = lan_rd(lan966x, PTP_TWOSTEP_STAMP);
		delay = PTP_TWOSTEP_STAMP_STAMP_NSEC_GET(delay);

		/* Get next timestamp from fifo, which needs to be the
		 * rx timestamp which represents the id of the frame
		 */
		lan_rmw(PTP_TWOSTEP_CTRL_NXT_SET(1),
			PTP_TWOSTEP_CTRL_NXT,
			lan966x, PTP_TWOSTEP_CTRL);

		val = lan_rd(lan966x, PTP_TWOSTEP_CTRL);

		/* Check if a timestamp can be retried */
		if (!(val & PTP_TWOSTEP_CTRL_VLD))
			break;

		/* Read RX timestamping to get the ID */
		id = lan_rd(lan966x, PTP_TWOSTEP_STAMP);

		spin_lock_irqsave(&port->tx_skbs.lock, flags);
		skb_queue_walk_safe(&port->tx_skbs, skb, skb_tmp) {
			if (LAN966X_SKB_CB(skb)->ts_id != id)
				continue;

			__skb_unlink(skb, &port->tx_skbs);
			skb_match = skb;
			break;
		}
		spin_unlock_irqrestore(&port->tx_skbs.lock, flags);

		/* Next ts */
		lan_rmw(PTP_TWOSTEP_CTRL_NXT_SET(1),
			PTP_TWOSTEP_CTRL_NXT,
			lan966x, PTP_TWOSTEP_CTRL);

		if (WARN_ON(!skb_match))
			continue;

		spin_lock(&lan966x->ptp_ts_id_lock);
		lan966x->ptp_skbs--;
		spin_unlock(&lan966x->ptp_ts_id_lock);

		/* Get the h/w timestamp */
		lan966x_get_hwtimestamp(lan966x, &ts, delay);

		/* Set the timestamp into the skb */
		shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
		skb_tstamp_tx(skb_match, &shhwtstamps);

		dev_kfree_skb_any(skb_match);
	}

	return IRQ_HANDLED;
}

static int lan966x_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
	struct lan966x_phc *phc = container_of(ptp, struct lan966x_phc, info);
	struct lan966x *lan966x = phc->lan966x;
	unsigned long flags;
	bool neg_adj = 0;
	u64 tod_inc;
	u64 ref;

	if (!scaled_ppm)
		return 0;

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

	tod_inc = lan966x_ptp_get_nominal_value();

	/* The multiplication is split in 2 separate additions because of
	 * overflow issues. If scaled_ppm with 16bit fractional part was bigger
	 * than 20ppm then we got overflow.
	 */
	ref = LAN966X_1PPM_FORMAT * (scaled_ppm >> 16);
	ref += (LAN966X_1PPM_FORMAT * (0xffff & scaled_ppm)) >> 16;
	tod_inc = neg_adj ? tod_inc - ref : tod_inc + ref;

	spin_lock_irqsave(&lan966x->ptp_clock_lock, flags);

	lan_rmw(PTP_DOM_CFG_CLKCFG_DIS_SET(1 << BIT(phc->index)),
		PTP_DOM_CFG_CLKCFG_DIS,
		lan966x, PTP_DOM_CFG);

	lan_wr((u32)tod_inc & 0xFFFFFFFF, lan966x,
	       PTP_CLK_PER_CFG(phc->index, 0));
	lan_wr((u32)(tod_inc >> 32), lan966x,
	       PTP_CLK_PER_CFG(phc->index, 1));

	lan_rmw(PTP_DOM_CFG_CLKCFG_DIS_SET(0),
		PTP_DOM_CFG_CLKCFG_DIS,
		lan966x, PTP_DOM_CFG);

	spin_unlock_irqrestore(&lan966x->ptp_clock_lock, flags);

	return 0;
}

static int lan966x_ptp_settime64(struct ptp_clock_info *ptp,
				 const struct timespec64 *ts)
{
	struct lan966x_phc *phc = container_of(ptp, struct lan966x_phc, info);
	struct lan966x *lan966x = phc->lan966x;
	unsigned long flags;

	spin_lock_irqsave(&lan966x->ptp_clock_lock, flags);

	/* Must be in IDLE mode before the time can be loaded */
	lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_IDLE) |
		PTP_PIN_CFG_PIN_DOM_SET(phc->index) |
		PTP_PIN_CFG_PIN_SYNC_SET(0),
		PTP_PIN_CFG_PIN_ACTION |
		PTP_PIN_CFG_PIN_DOM |
		PTP_PIN_CFG_PIN_SYNC,
		lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

	/* Set new value */
	lan_wr(PTP_TOD_SEC_MSB_TOD_SEC_MSB_SET(upper_32_bits(ts->tv_sec)),
	       lan966x, PTP_TOD_SEC_MSB(TOD_ACC_PIN));
	lan_wr(lower_32_bits(ts->tv_sec),
	       lan966x, PTP_TOD_SEC_LSB(TOD_ACC_PIN));
	lan_wr(ts->tv_nsec, lan966x, PTP_TOD_NSEC(TOD_ACC_PIN));

	/* Apply new values */
	lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_LOAD) |
		PTP_PIN_CFG_PIN_DOM_SET(phc->index) |
		PTP_PIN_CFG_PIN_SYNC_SET(0),
		PTP_PIN_CFG_PIN_ACTION |
		PTP_PIN_CFG_PIN_DOM |
		PTP_PIN_CFG_PIN_SYNC,
		lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

	spin_unlock_irqrestore(&lan966x->ptp_clock_lock, flags);

	return 0;
}

static int lan966x_ptp_gettime64(struct ptp_clock_info *ptp,
				 struct timespec64 *ts)
{
	struct lan966x_phc *phc = container_of(ptp, struct lan966x_phc, info);
	struct lan966x *lan966x = phc->lan966x;
	unsigned long flags;
	time64_t s;
	s64 ns;

	spin_lock_irqsave(&lan966x->ptp_clock_lock, flags);

	lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_SAVE) |
		PTP_PIN_CFG_PIN_DOM_SET(phc->index) |
		PTP_PIN_CFG_PIN_SYNC_SET(0),
		PTP_PIN_CFG_PIN_ACTION |
		PTP_PIN_CFG_PIN_DOM |
		PTP_PIN_CFG_PIN_SYNC,
		lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

	s = lan_rd(lan966x, PTP_TOD_SEC_MSB(TOD_ACC_PIN));
	s <<= 32;
	s |= lan_rd(lan966x, PTP_TOD_SEC_LSB(TOD_ACC_PIN));
	ns = lan_rd(lan966x, PTP_TOD_NSEC(TOD_ACC_PIN));
	ns &= PTP_TOD_NSEC_TOD_NSEC;

	spin_unlock_irqrestore(&lan966x->ptp_clock_lock, flags);

	/* Deal with negative values */
	if ((ns & 0xFFFFFFF0) == 0x3FFFFFF0) {
		s--;
		ns &= 0xf;
		ns += 999999984;
	}

	set_normalized_timespec64(ts, s, ns);
	return 0;
}

static int lan966x_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	struct lan966x_phc *phc = container_of(ptp, struct lan966x_phc, info);
	struct lan966x *lan966x = phc->lan966x;

	if (delta > -(NSEC_PER_SEC / 2) && delta < (NSEC_PER_SEC / 2)) {
		unsigned long flags;

		spin_lock_irqsave(&lan966x->ptp_clock_lock, flags);

		/* Must be in IDLE mode before the time can be loaded */
		lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_IDLE) |
			PTP_PIN_CFG_PIN_DOM_SET(phc->index) |
			PTP_PIN_CFG_PIN_SYNC_SET(0),
			PTP_PIN_CFG_PIN_ACTION |
			PTP_PIN_CFG_PIN_DOM |
			PTP_PIN_CFG_PIN_SYNC,
			lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

		lan_wr(PTP_TOD_NSEC_TOD_NSEC_SET(delta),
		       lan966x, PTP_TOD_NSEC(TOD_ACC_PIN));

		/* Adjust time with the value of PTP_TOD_NSEC */
		lan_rmw(PTP_PIN_CFG_PIN_ACTION_SET(PTP_PIN_ACTION_DELTA) |
			PTP_PIN_CFG_PIN_DOM_SET(phc->index) |
			PTP_PIN_CFG_PIN_SYNC_SET(0),
			PTP_PIN_CFG_PIN_ACTION |
			PTP_PIN_CFG_PIN_DOM |
			PTP_PIN_CFG_PIN_SYNC,
			lan966x, PTP_PIN_CFG(TOD_ACC_PIN));

		spin_unlock_irqrestore(&lan966x->ptp_clock_lock, flags);
	} else {
		/* Fall back using lan966x_ptp_settime64 which is not exact */
		struct timespec64 ts;
		u64 now;

		lan966x_ptp_gettime64(ptp, &ts);

		now = ktime_to_ns(timespec64_to_ktime(ts));
		ts = ns_to_timespec64(now + delta);

		lan966x_ptp_settime64(ptp, &ts);
	}

	return 0;
}

static struct ptp_clock_info lan966x_ptp_clock_info = {
	.owner		= THIS_MODULE,
	.name		= "lan966x ptp",
	.max_adj	= 200000,
	.gettime64	= lan966x_ptp_gettime64,
	.settime64	= lan966x_ptp_settime64,
	.adjtime	= lan966x_ptp_adjtime,
	.adjfine	= lan966x_ptp_adjfine,
};

static int lan966x_ptp_phc_init(struct lan966x *lan966x,
				int index,
				struct ptp_clock_info *clock_info)
{
	struct lan966x_phc *phc = &lan966x->phc[index];

	phc->info = *clock_info;
	phc->clock = ptp_clock_register(&phc->info, lan966x->dev);
	if (IS_ERR(phc->clock))
		return PTR_ERR(phc->clock);

	phc->index = index;
	phc->lan966x = lan966x;

	/* PTP Rx stamping is always enabled.  */
	phc->hwtstamp_config.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;

	return 0;
}

int lan966x_ptp_init(struct lan966x *lan966x)
{
	u64 tod_adj = lan966x_ptp_get_nominal_value();
	struct lan966x_port *port;
	int err, i;

	if (!lan966x->ptp)
		return 0;

	for (i = 0; i < LAN966X_PHC_COUNT; ++i) {
		err = lan966x_ptp_phc_init(lan966x, i, &lan966x_ptp_clock_info);
		if (err)
			return err;
	}

	spin_lock_init(&lan966x->ptp_clock_lock);
	spin_lock_init(&lan966x->ptp_ts_id_lock);
	mutex_init(&lan966x->ptp_lock);

	/* Disable master counters */
	lan_wr(PTP_DOM_CFG_ENA_SET(0), lan966x, PTP_DOM_CFG);

	/* Configure the nominal TOD increment per clock cycle */
	lan_rmw(PTP_DOM_CFG_CLKCFG_DIS_SET(0x7),
		PTP_DOM_CFG_CLKCFG_DIS,
		lan966x, PTP_DOM_CFG);

	for (i = 0; i < LAN966X_PHC_COUNT; ++i) {
		lan_wr((u32)tod_adj & 0xFFFFFFFF, lan966x,
		       PTP_CLK_PER_CFG(i, 0));
		lan_wr((u32)(tod_adj >> 32), lan966x,
		       PTP_CLK_PER_CFG(i, 1));
	}

	lan_rmw(PTP_DOM_CFG_CLKCFG_DIS_SET(0),
		PTP_DOM_CFG_CLKCFG_DIS,
		lan966x, PTP_DOM_CFG);

	/* Enable master counters */
	lan_wr(PTP_DOM_CFG_ENA_SET(0x7), lan966x, PTP_DOM_CFG);

	for (i = 0; i < lan966x->num_phys_ports; i++) {
		port = lan966x->ports[i];
		if (!port)
			continue;

		skb_queue_head_init(&port->tx_skbs);
	}

	return 0;
}

void lan966x_ptp_deinit(struct lan966x *lan966x)
{
	struct lan966x_port *port;
	int i;

	for (i = 0; i < lan966x->num_phys_ports; i++) {
		port = lan966x->ports[i];
		if (!port)
			continue;

		skb_queue_purge(&port->tx_skbs);
	}

	for (i = 0; i < LAN966X_PHC_COUNT; ++i)
		ptp_clock_unregister(lan966x->phc[i].clock);
}

void lan966x_ptp_rxtstamp(struct lan966x *lan966x, struct sk_buff *skb,
			  u64 timestamp)
{
	struct skb_shared_hwtstamps *shhwtstamps;
	struct lan966x_phc *phc;
	struct timespec64 ts;
	u64 full_ts_in_ns;

	if (!lan966x->ptp)
		return;

	phc = &lan966x->phc[LAN966X_PHC_PORT];
	lan966x_ptp_gettime64(&phc->info, &ts);

	/* Drop the sub-ns precision */
	timestamp = timestamp >> 2;
	if (ts.tv_nsec < timestamp)
		ts.tv_sec--;
	ts.tv_nsec = timestamp;
	full_ts_in_ns = ktime_set(ts.tv_sec, ts.tv_nsec);

	shhwtstamps = skb_hwtstamps(skb);
	shhwtstamps->hwtstamp = full_ts_in_ns;
}