ptp_ines.c

// SPDX-License-Identifier: GPL-2.0
//
// Copyright (C) 2018 MOSER-BAER AG
//

#define pr_fmt(fmt) "InES_PTP: " fmt

#include <linux/ethtool.h>
#include <linux/export.h>
#include <linux/if_vlan.h>
#include <linux/mii_timestamper.h>
#include <linux/module.h>
#include <linux/net_tstamp.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/ptp_classify.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/stddef.h>

MODULE_DESCRIPTION("Driver for the ZHAW InES PTP time stamping IP core");
MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");

/* GLOBAL register */
#define MCAST_MAC_SELECT_SHIFT	2
#define MCAST_MAC_SELECT_MASK	0x3
#define IO_RESET		BIT(1)
#define PTP_RESET		BIT(0)

/* VERSION register */
#define IF_MAJOR_VER_SHIFT	12
#define IF_MAJOR_VER_MASK	0xf
#define IF_MINOR_VER_SHIFT	8
#define IF_MINOR_VER_MASK	0xf
#define FPGA_MAJOR_VER_SHIFT	4
#define FPGA_MAJOR_VER_MASK	0xf
#define FPGA_MINOR_VER_SHIFT	0
#define FPGA_MINOR_VER_MASK	0xf

/* INT_STAT register */
#define RX_INTR_STATUS_3	BIT(5)
#define RX_INTR_STATUS_2	BIT(4)
#define RX_INTR_STATUS_1	BIT(3)
#define TX_INTR_STATUS_3	BIT(2)
#define TX_INTR_STATUS_2	BIT(1)
#define TX_INTR_STATUS_1	BIT(0)

/* INT_MSK register */
#define RX_INTR_MASK_3		BIT(5)
#define RX_INTR_MASK_2		BIT(4)
#define RX_INTR_MASK_1		BIT(3)
#define TX_INTR_MASK_3		BIT(2)
#define TX_INTR_MASK_2		BIT(1)
#define TX_INTR_MASK_1		BIT(0)

/* BUF_STAT register */
#define RX_FIFO_NE_3		BIT(5)
#define RX_FIFO_NE_2		BIT(4)
#define RX_FIFO_NE_1		BIT(3)
#define TX_FIFO_NE_3		BIT(2)
#define TX_FIFO_NE_2		BIT(1)
#define TX_FIFO_NE_1		BIT(0)

/* PORT_CONF register */
#define CM_ONE_STEP		BIT(6)
#define PHY_SPEED_SHIFT		4
#define PHY_SPEED_MASK		0x3
#define P2P_DELAY_WR_POS_SHIFT	2
#define P2P_DELAY_WR_POS_MASK	0x3
#define PTP_MODE_SHIFT		0
#define PTP_MODE_MASK		0x3

/* TS_STAT_TX register */
#define TS_ENABLE		BIT(15)
#define DATA_READ_POS_SHIFT	8
#define DATA_READ_POS_MASK	0x1f
#define DISCARDED_EVENTS_SHIFT	4
#define DISCARDED_EVENTS_MASK	0xf

#define INES_N_PORTS		3
#define INES_REGISTER_SIZE	0x80
#define INES_PORT_OFFSET	0x20
#define INES_PORT_SIZE		0x20
#define INES_FIFO_DEPTH		90
#define INES_MAX_EVENTS		100

#define BC_PTP_V1		0
#define BC_PTP_V2		1
#define TC_E2E_PTP_V2		2
#define TC_P2P_PTP_V2		3

#define PHY_SPEED_10		0
#define PHY_SPEED_100		1
#define PHY_SPEED_1000		2

#define PORT_CONF \
	((PHY_SPEED_1000 << PHY_SPEED_SHIFT) | (BC_PTP_V2 << PTP_MODE_SHIFT))

#define ines_read32(s, r)	__raw_readl((void __iomem *)&s->regs->r)
#define ines_write32(s, v, r)	__raw_writel(v, (void __iomem *)&s->regs->r)

#define MESSAGE_TYPE_SYNC		1
#define MESSAGE_TYPE_P_DELAY_REQ	2
#define MESSAGE_TYPE_P_DELAY_RESP	3
#define MESSAGE_TYPE_DELAY_REQ		4

#define SYNC				0x0
#define DELAY_REQ			0x1
#define PDELAY_REQ			0x2
#define PDELAY_RESP			0x3

static LIST_HEAD(ines_clocks);
static DEFINE_MUTEX(ines_clocks_lock);

struct ines_global_regs {
	u32 id;
	u32 test;
	u32 global;
	u32 version;
	u32 test2;
	u32 int_stat;
	u32 int_msk;
	u32 buf_stat;
};

struct ines_port_registers {
	u32 port_conf;
	u32 p_delay;
	u32 ts_stat_tx;
	u32 ts_stat_rx;
	u32 ts_tx;
	u32 ts_rx;
};

struct ines_timestamp {
	struct list_head list;
	unsigned long	tmo;
	u16		tag;
	u64		sec;
	u64		nsec;
	u64		clkid;
	u16		portnum;
	u16		seqid;
};

struct ines_port {
	struct ines_port_registers	*regs;
	struct mii_timestamper		mii_ts;
	struct ines_clock		*clock;
	bool				rxts_enabled;
	bool				txts_enabled;
	unsigned int			index;
	struct delayed_work		ts_work;
	/* lock protects event list and tx_skb */
	spinlock_t			lock;
	struct sk_buff			*tx_skb;
	struct list_head		events;
	struct list_head		pool;
	struct ines_timestamp		pool_data[INES_MAX_EVENTS];
};

struct ines_clock {
	struct ines_port		port[INES_N_PORTS];
	struct ines_global_regs __iomem	*regs;
	void __iomem			*base;
	struct device_node		*node;
	struct device			*dev;
	struct list_head		list;
};

static bool ines_match(struct sk_buff *skb, unsigned int ptp_class,
		       struct ines_timestamp *ts, struct device *dev);
static int ines_rxfifo_read(struct ines_port *port);
static u64 ines_rxts64(struct ines_port *port, unsigned int words);
static bool ines_timestamp_expired(struct ines_timestamp *ts);
static u64 ines_txts64(struct ines_port *port, unsigned int words);
static void ines_txtstamp_work(struct work_struct *work);
static bool is_sync_pdelay_resp(struct sk_buff *skb, int type);
static u8 tag_to_msgtype(u8 tag);

static void ines_clock_cleanup(struct ines_clock *clock)
{
	struct ines_port *port;
	int i;

	for (i = 0; i < INES_N_PORTS; i++) {
		port = &clock->port[i];
		cancel_delayed_work_sync(&port->ts_work);
	}
}

static int ines_clock_init(struct ines_clock *clock, struct device *device,
			   void __iomem *addr)
{
	struct device_node *node = device->of_node;
	unsigned long port_addr;
	struct ines_port *port;
	int i, j;

	INIT_LIST_HEAD(&clock->list);
	clock->node = node;
	clock->dev  = device;
	clock->base = addr;
	clock->regs = clock->base;

	for (i = 0; i < INES_N_PORTS; i++) {
		port = &clock->port[i];
		port_addr = (unsigned long) clock->base +
			INES_PORT_OFFSET + i * INES_PORT_SIZE;
		port->regs = (struct ines_port_registers *) port_addr;
		port->clock = clock;
		port->index = i;
		INIT_DELAYED_WORK(&port->ts_work, ines_txtstamp_work);
		spin_lock_init(&port->lock);
		INIT_LIST_HEAD(&port->events);
		INIT_LIST_HEAD(&port->pool);
		for (j = 0; j < INES_MAX_EVENTS; j++)
			list_add(&port->pool_data[j].list, &port->pool);
	}

	ines_write32(clock, 0xBEEF, test);
	ines_write32(clock, 0xBEEF, test2);

	dev_dbg(device, "ID      0x%x\n", ines_read32(clock, id));
	dev_dbg(device, "TEST    0x%x\n", ines_read32(clock, test));
	dev_dbg(device, "VERSION 0x%x\n", ines_read32(clock, version));
	dev_dbg(device, "TEST2   0x%x\n", ines_read32(clock, test2));

	for (i = 0; i < INES_N_PORTS; i++) {
		port = &clock->port[i];
		ines_write32(port, PORT_CONF, port_conf);
	}

	return 0;
}

static struct ines_port *ines_find_port(struct device_node *node, u32 index)
{
	struct ines_port *port = NULL;
	struct ines_clock *clock;
	struct list_head *this;

	mutex_lock(&ines_clocks_lock);
	list_for_each(this, &ines_clocks) {
		clock = list_entry(this, struct ines_clock, list);
		if (clock->node == node) {
			port = &clock->port[index];
			break;
		}
	}
	mutex_unlock(&ines_clocks_lock);
	return port;
}

static u64 ines_find_rxts(struct ines_port *port, struct sk_buff *skb, int type)
{
	struct list_head *this, *next;
	struct ines_timestamp *ts;
	unsigned long flags;
	u64 ns = 0;

	if (type == PTP_CLASS_NONE)
		return 0;

	spin_lock_irqsave(&port->lock, flags);
	ines_rxfifo_read(port);
	list_for_each_safe(this, next, &port->events) {
		ts = list_entry(this, struct ines_timestamp, list);
		if (ines_timestamp_expired(ts)) {
			list_del_init(&ts->list);
			list_add(&ts->list, &port->pool);
			continue;
		}
		if (ines_match(skb, type, ts, port->clock->dev)) {
			ns = ts->sec * 1000000000ULL + ts->nsec;
			list_del_init(&ts->list);
			list_add(&ts->list, &port->pool);
			break;
		}
	}
	spin_unlock_irqrestore(&port->lock, flags);

	return ns;
}

static u64 ines_find_txts(struct ines_port *port, struct sk_buff *skb)
{
	unsigned int class = ptp_classify_raw(skb), i;
	u32 data_rd_pos, buf_stat, mask, ts_stat_tx;
	struct ines_timestamp ts;
	unsigned long flags;
	u64 ns = 0;

	mask = TX_FIFO_NE_1 << port->index;

	spin_lock_irqsave(&port->lock, flags);

	for (i = 0; i < INES_FIFO_DEPTH; i++) {

		buf_stat = ines_read32(port->clock, buf_stat);
		if (!(buf_stat & mask)) {
			dev_dbg(port->clock->dev,
				  "Tx timestamp FIFO unexpectedly empty\n");
			break;
		}
		ts_stat_tx = ines_read32(port, ts_stat_tx);
		data_rd_pos = (ts_stat_tx >> DATA_READ_POS_SHIFT) &
			DATA_READ_POS_MASK;
		if (data_rd_pos) {
			dev_err(port->clock->dev,
				"unexpected Tx read pos %u\n", data_rd_pos);
			break;
		}

		ts.tag     = ines_read32(port, ts_tx);
		ts.sec     = ines_txts64(port, 3);
		ts.nsec    = ines_txts64(port, 2);
		ts.clkid   = ines_txts64(port, 4);
		ts.portnum = ines_read32(port, ts_tx);
		ts.seqid   = ines_read32(port, ts_tx);

		if (ines_match(skb, class, &ts, port->clock->dev)) {
			ns = ts.sec * 1000000000ULL + ts.nsec;
			break;
		}
	}

	spin_unlock_irqrestore(&port->lock, flags);
	return ns;
}

static int ines_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
{
	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
	u32 cm_one_step = 0, port_conf, ts_stat_rx, ts_stat_tx;
	struct hwtstamp_config cfg;
	unsigned long flags;

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

	/* reserved for future extensions */
	if (cfg.flags)
		return -EINVAL;

	switch (cfg.tx_type) {
	case HWTSTAMP_TX_OFF:
		ts_stat_tx = 0;
		break;
	case HWTSTAMP_TX_ON:
		ts_stat_tx = TS_ENABLE;
		break;
	case HWTSTAMP_TX_ONESTEP_P2P:
		ts_stat_tx = TS_ENABLE;
		cm_one_step = CM_ONE_STEP;
		break;
	default:
		return -ERANGE;
	}

	switch (cfg.rx_filter) {
	case HWTSTAMP_FILTER_NONE:
		ts_stat_rx = 0;
		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:
		return -ERANGE;
	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:
		ts_stat_rx = TS_ENABLE;
		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
		break;
	default:
		return -ERANGE;
	}

	spin_lock_irqsave(&port->lock, flags);

	port_conf = ines_read32(port, port_conf);
	port_conf &= ~CM_ONE_STEP;
	port_conf |= cm_one_step;

	ines_write32(port, port_conf, port_conf);
	ines_write32(port, ts_stat_rx, ts_stat_rx);
	ines_write32(port, ts_stat_tx, ts_stat_tx);

	port->rxts_enabled = ts_stat_rx == TS_ENABLE;
	port->txts_enabled = ts_stat_tx == TS_ENABLE;

	spin_unlock_irqrestore(&port->lock, flags);

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

static void ines_link_state(struct mii_timestamper *mii_ts,
			    struct phy_device *phydev)
{
	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
	u32 port_conf, speed_conf;
	unsigned long flags;

	switch (phydev->speed) {
	case SPEED_10:
		speed_conf = PHY_SPEED_10 << PHY_SPEED_SHIFT;
		break;
	case SPEED_100:
		speed_conf = PHY_SPEED_100 << PHY_SPEED_SHIFT;
		break;
	case SPEED_1000:
		speed_conf = PHY_SPEED_1000 << PHY_SPEED_SHIFT;
		break;
	default:
		dev_err(port->clock->dev, "bad speed: %d\n", phydev->speed);
		return;
	}
	spin_lock_irqsave(&port->lock, flags);

	port_conf = ines_read32(port, port_conf);
	port_conf &= ~(0x3 << PHY_SPEED_SHIFT);
	port_conf |= speed_conf;

	ines_write32(port, port_conf, port_conf);

	spin_unlock_irqrestore(&port->lock, flags);
}

static bool ines_match(struct sk_buff *skb, unsigned int ptp_class,
		       struct ines_timestamp *ts, struct device *dev)
{
	struct ptp_header *hdr;
	u16 portn, seqid;
	u8 msgtype;
	u64 clkid;

	if (unlikely(ptp_class & PTP_CLASS_V1))
		return false;

	hdr = ptp_parse_header(skb, ptp_class);
	if (!hdr)
		return false;

	msgtype = ptp_get_msgtype(hdr, ptp_class);
	clkid = be64_to_cpup((__be64 *)&hdr->source_port_identity.clock_identity.id[0]);
	portn = be16_to_cpu(hdr->source_port_identity.port_number);
	seqid = be16_to_cpu(hdr->sequence_id);

	if (tag_to_msgtype(ts->tag & 0x7) != msgtype) {
		dev_dbg(dev, "msgtype mismatch ts %hhu != skb %hhu\n",
			tag_to_msgtype(ts->tag & 0x7), msgtype);
		return false;
	}
	if (ts->clkid != clkid) {
		dev_dbg(dev, "clkid mismatch ts %llx != skb %llx\n",
			ts->clkid, clkid);
		return false;
	}
	if (ts->portnum != portn) {
		dev_dbg(dev, "portn mismatch ts %hu != skb %hu\n",
			ts->portnum, portn);
		return false;
	}
	if (ts->seqid != seqid) {
		dev_dbg(dev, "seqid mismatch ts %hu != skb %hu\n",
			ts->seqid, seqid);
		return false;
	}

	return true;
}

static bool ines_rxtstamp(struct mii_timestamper *mii_ts,
			  struct sk_buff *skb, int type)
{
	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
	struct skb_shared_hwtstamps *ssh;
	u64 ns;

	if (!port->rxts_enabled)
		return false;

	ns = ines_find_rxts(port, skb, type);
	if (!ns)
		return false;

	ssh = skb_hwtstamps(skb);
	ssh->hwtstamp = ns_to_ktime(ns);
	netif_rx(skb);

	return true;
}

static int ines_rxfifo_read(struct ines_port *port)
{
	u32 data_rd_pos, buf_stat, mask, ts_stat_rx;
	struct ines_timestamp *ts;
	unsigned int i;

	mask = RX_FIFO_NE_1 << port->index;

	for (i = 0; i < INES_FIFO_DEPTH; i++) {
		if (list_empty(&port->pool)) {
			dev_err(port->clock->dev, "event pool is empty\n");
			return -1;
		}
		buf_stat = ines_read32(port->clock, buf_stat);
		if (!(buf_stat & mask))
			break;

		ts_stat_rx = ines_read32(port, ts_stat_rx);
		data_rd_pos = (ts_stat_rx >> DATA_READ_POS_SHIFT) &
			DATA_READ_POS_MASK;
		if (data_rd_pos) {
			dev_err(port->clock->dev, "unexpected Rx read pos %u\n",
				data_rd_pos);
			break;
		}

		ts = list_first_entry(&port->pool, struct ines_timestamp, list);
		ts->tmo     = jiffies + HZ;
		ts->tag     = ines_read32(port, ts_rx);
		ts->sec     = ines_rxts64(port, 3);
		ts->nsec    = ines_rxts64(port, 2);
		ts->clkid   = ines_rxts64(port, 4);
		ts->portnum = ines_read32(port, ts_rx);
		ts->seqid   = ines_read32(port, ts_rx);

		list_del_init(&ts->list);
		list_add_tail(&ts->list, &port->events);
	}

	return 0;
}

static u64 ines_rxts64(struct ines_port *port, unsigned int words)
{
	unsigned int i;
	u64 result;
	u16 word;

	word = ines_read32(port, ts_rx);
	result = word;
	words--;
	for (i = 0; i < words; i++) {
		word = ines_read32(port, ts_rx);
		result <<= 16;
		result |= word;
	}
	return result;
}

static bool ines_timestamp_expired(struct ines_timestamp *ts)
{
	return time_after(jiffies, ts->tmo);
}

static int ines_ts_info(struct mii_timestamper *mii_ts,
			struct ethtool_ts_info *info)
{
	info->so_timestamping =
		SOF_TIMESTAMPING_TX_HARDWARE |
		SOF_TIMESTAMPING_TX_SOFTWARE |
		SOF_TIMESTAMPING_RX_HARDWARE |
		SOF_TIMESTAMPING_RX_SOFTWARE |
		SOF_TIMESTAMPING_SOFTWARE |
		SOF_TIMESTAMPING_RAW_HARDWARE;

	info->phc_index = -1;

	info->tx_types =
		(1 << HWTSTAMP_TX_OFF) |
		(1 << HWTSTAMP_TX_ON) |
		(1 << HWTSTAMP_TX_ONESTEP_P2P);

	info->rx_filters =
		(1 << HWTSTAMP_FILTER_NONE) |
		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT);

	return 0;
}

static u64 ines_txts64(struct ines_port *port, unsigned int words)
{
	unsigned int i;
	u64 result;
	u16 word;

	word = ines_read32(port, ts_tx);
	result = word;
	words--;
	for (i = 0; i < words; i++) {
		word = ines_read32(port, ts_tx);
		result <<= 16;
		result |= word;
	}
	return result;
}

static bool ines_txts_onestep(struct ines_port *port, struct sk_buff *skb, int type)
{
	unsigned long flags;
	u32 port_conf;

	spin_lock_irqsave(&port->lock, flags);
	port_conf = ines_read32(port, port_conf);
	spin_unlock_irqrestore(&port->lock, flags);

	if (port_conf & CM_ONE_STEP)
		return is_sync_pdelay_resp(skb, type);

	return false;
}

static void ines_txtstamp(struct mii_timestamper *mii_ts,
			  struct sk_buff *skb, int type)
{
	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
	struct sk_buff *old_skb = NULL;
	unsigned long flags;

	if (!port->txts_enabled || ines_txts_onestep(port, skb, type)) {
		kfree_skb(skb);
		return;
	}

	spin_lock_irqsave(&port->lock, flags);

	if (port->tx_skb)
		old_skb = port->tx_skb;

	port->tx_skb = skb;

	spin_unlock_irqrestore(&port->lock, flags);

	kfree_skb(old_skb);

	schedule_delayed_work(&port->ts_work, 1);
}

static void ines_txtstamp_work(struct work_struct *work)
{
	struct ines_port *port =
		container_of(work, struct ines_port, ts_work.work);
	struct skb_shared_hwtstamps ssh;
	struct sk_buff *skb;
	unsigned long flags;
	u64 ns;

	spin_lock_irqsave(&port->lock, flags);
	skb = port->tx_skb;
	port->tx_skb = NULL;
	spin_unlock_irqrestore(&port->lock, flags);

	ns = ines_find_txts(port, skb);
	if (!ns) {
		kfree_skb(skb);
		return;
	}
	ssh.hwtstamp = ns_to_ktime(ns);
	skb_complete_tx_timestamp(skb, &ssh);
}

static bool is_sync_pdelay_resp(struct sk_buff *skb, int type)
{
	struct ptp_header *hdr;
	u8 msgtype;

	hdr = ptp_parse_header(skb, type);
	if (!hdr)
		return false;

	msgtype = ptp_get_msgtype(hdr, type);

	switch ((msgtype & 0xf)) {
	case SYNC:
	case PDELAY_RESP:
		return true;
	default:
		return false;
	}
}

static u8 tag_to_msgtype(u8 tag)
{
	switch (tag) {
	case MESSAGE_TYPE_SYNC:
		return SYNC;
	case MESSAGE_TYPE_P_DELAY_REQ:
		return PDELAY_REQ;
	case MESSAGE_TYPE_P_DELAY_RESP:
		return PDELAY_RESP;
	case MESSAGE_TYPE_DELAY_REQ:
		return DELAY_REQ;
	}
	return 0xf;
}

static struct mii_timestamper *ines_ptp_probe_channel(struct device *device,
						      unsigned int index)
{
	struct device_node *node = device->of_node;
	struct ines_port *port;

	if (index > INES_N_PORTS - 1) {
		dev_err(device, "bad port index %u\n", index);
		return ERR_PTR(-EINVAL);
	}
	port = ines_find_port(node, index);
	if (!port) {
		dev_err(device, "missing port index %u\n", index);
		return ERR_PTR(-ENODEV);
	}
	port->mii_ts.rxtstamp = ines_rxtstamp;
	port->mii_ts.txtstamp = ines_txtstamp;
	port->mii_ts.hwtstamp = ines_hwtstamp;
	port->mii_ts.link_state = ines_link_state;
	port->mii_ts.ts_info = ines_ts_info;

	return &port->mii_ts;
}

static void ines_ptp_release_channel(struct device *device,
				     struct mii_timestamper *mii_ts)
{
}

static struct mii_timestamping_ctrl ines_ctrl = {
	.probe_channel = ines_ptp_probe_channel,
	.release_channel = ines_ptp_release_channel,
};

static int ines_ptp_ctrl_probe(struct platform_device *pld)
{
	struct ines_clock *clock;
	void __iomem *addr;
	int err = 0;

	addr = devm_platform_ioremap_resource(pld, 0);
	if (IS_ERR(addr)) {
		err = PTR_ERR(addr);
		goto out;
	}
	clock = kzalloc(sizeof(*clock), GFP_KERNEL);
	if (!clock) {
		err = -ENOMEM;
		goto out;
	}
	if (ines_clock_init(clock, &pld->dev, addr)) {
		kfree(clock);
		err = -ENOMEM;
		goto out;
	}
	err = register_mii_tstamp_controller(&pld->dev, &ines_ctrl);
	if (err) {
		kfree(clock);
		goto out;
	}
	mutex_lock(&ines_clocks_lock);
	list_add_tail(&ines_clocks, &clock->list);
	mutex_unlock(&ines_clocks_lock);

	dev_set_drvdata(&pld->dev, clock);
out:
	return err;
}

static int ines_ptp_ctrl_remove(struct platform_device *pld)
{
	struct ines_clock *clock = dev_get_drvdata(&pld->dev);

	unregister_mii_tstamp_controller(&pld->dev);
	mutex_lock(&ines_clocks_lock);
	list_del(&clock->list);
	mutex_unlock(&ines_clocks_lock);
	ines_clock_cleanup(clock);
	kfree(clock);
	return 0;
}

static const struct of_device_id ines_ptp_ctrl_of_match[] = {
	{ .compatible = "ines,ptp-ctrl" },
	{ }
};

MODULE_DEVICE_TABLE(of, ines_ptp_ctrl_of_match);

static struct platform_driver ines_ptp_ctrl_driver = {
	.probe  = ines_ptp_ctrl_probe,
	.remove = ines_ptp_ctrl_remove,
	.driver = {
		.name = "ines_ptp_ctrl",
		.of_match_table = of_match_ptr(ines_ptp_ctrl_of_match),
	},
};
module_platform_driver(ines_ptp_ctrl_driver);