Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1454 insertions, 0 deletions

diff --git a/drivers/net/caif/caif_hsi.c b/drivers/net/caif/caif_hsi.c
new file mode 100644
index 000000000..3d63b15bb
--- /dev/null
+++ b/drivers/net/caif/caif_hsi.c
@@ -0,0 +1,1454 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Author:  Daniel Martensson
+ *	    Dmitry.Tarnyagin  / dmitry.tarnyagin@lockless.no
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME fmt
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/netdevice.h>
+#include <linux/string.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/if_arp.h>
+#include <linux/timer.h>
+#include <net/rtnetlink.h>
+#include <linux/pkt_sched.h>
+#include <net/caif/caif_layer.h>
+#include <net/caif/caif_hsi.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Martensson");
+MODULE_DESCRIPTION("CAIF HSI driver");
+
+/* Returns the number of padding bytes for alignment. */
+#define PAD_POW2(x, pow) ((((x)&((pow)-1)) == 0) ? 0 :\
+				(((pow)-((x)&((pow)-1)))))
+
+static const struct cfhsi_config  hsi_default_config = {
+
+	/* Inactivity timeout on HSI, ms */
+	.inactivity_timeout = HZ,
+
+	/* Aggregation timeout (ms) of zero means no aggregation is done*/
+	.aggregation_timeout = 1,
+
+	/*
+	 * HSI link layer flow-control thresholds.
+	 * Threshold values for the HSI packet queue. Flow-control will be
+	 * asserted when the number of packets exceeds q_high_mark. It will
+	 * not be de-asserted before the number of packets drops below
+	 * q_low_mark.
+	 * Warning: A high threshold value might increase throughput but it
+	 * will at the same time prevent channel prioritization and increase
+	 * the risk of flooding the modem. The high threshold should be above
+	 * the low.
+	 */
+	.q_high_mark = 100,
+	.q_low_mark = 50,
+
+	/*
+	 * HSI padding options.
+	 * Warning: must be a base of 2 (& operation used) and can not be zero !
+	 */
+	.head_align = 4,
+	.tail_align = 4,
+};
+
+#define ON 1
+#define OFF 0
+
+static LIST_HEAD(cfhsi_list);
+
+static void cfhsi_inactivity_tout(struct timer_list *t)
+{
+	struct cfhsi *cfhsi = from_timer(cfhsi, t, inactivity_timer);
+
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	/* Schedule power down work queue. */
+	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		queue_work(cfhsi->wq, &cfhsi->wake_down_work);
+}
+
+static void cfhsi_update_aggregation_stats(struct cfhsi *cfhsi,
+					   const struct sk_buff *skb,
+					   int direction)
+{
+	struct caif_payload_info *info;
+	int hpad, tpad, len;
+
+	info = (struct caif_payload_info *)&skb->cb;
+	hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
+	tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
+	len = skb->len + hpad + tpad;
+
+	if (direction > 0)
+		cfhsi->aggregation_len += len;
+	else if (direction < 0)
+		cfhsi->aggregation_len -= len;
+}
+
+static bool cfhsi_can_send_aggregate(struct cfhsi *cfhsi)
+{
+	int i;
+
+	if (cfhsi->cfg.aggregation_timeout == 0)
+		return true;
+
+	for (i = 0; i < CFHSI_PRIO_BEBK; ++i) {
+		if (cfhsi->qhead[i].qlen)
+			return true;
+	}
+
+	/* TODO: Use aggregation_len instead */
+	if (cfhsi->qhead[CFHSI_PRIO_BEBK].qlen >= CFHSI_MAX_PKTS)
+		return true;
+
+	return false;
+}
+
+static struct sk_buff *cfhsi_dequeue(struct cfhsi *cfhsi)
+{
+	struct sk_buff *skb;
+	int i;
+
+	for (i = 0; i < CFHSI_PRIO_LAST; ++i) {
+		skb = skb_dequeue(&cfhsi->qhead[i]);
+		if (skb)
+			break;
+	}
+
+	return skb;
+}
+
+static int cfhsi_tx_queue_len(struct cfhsi *cfhsi)
+{
+	int i, len = 0;
+	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
+		len += skb_queue_len(&cfhsi->qhead[i]);
+	return len;
+}
+
+static void cfhsi_abort_tx(struct cfhsi *cfhsi)
+{
+	struct sk_buff *skb;
+
+	for (;;) {
+		spin_lock_bh(&cfhsi->lock);
+		skb = cfhsi_dequeue(cfhsi);
+		if (!skb)
+			break;
+
+		cfhsi->ndev->stats.tx_errors++;
+		cfhsi->ndev->stats.tx_dropped++;
+		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
+		spin_unlock_bh(&cfhsi->lock);
+		kfree_skb(skb);
+	}
+	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
+	if (!test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		mod_timer(&cfhsi->inactivity_timer,
+			jiffies + cfhsi->cfg.inactivity_timeout);
+	spin_unlock_bh(&cfhsi->lock);
+}
+
+static int cfhsi_flush_fifo(struct cfhsi *cfhsi)
+{
+	char buffer[32]; /* Any reasonable value */
+	size_t fifo_occupancy;
+	int ret;
+
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	do {
+		ret = cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
+				&fifo_occupancy);
+		if (ret) {
+			netdev_warn(cfhsi->ndev,
+				"%s: can't get FIFO occupancy: %d.\n",
+				__func__, ret);
+			break;
+		} else if (!fifo_occupancy)
+			/* No more data, exitting normally */
+			break;
+
+		fifo_occupancy = min(sizeof(buffer), fifo_occupancy);
+		set_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
+		ret = cfhsi->ops->cfhsi_rx(buffer, fifo_occupancy,
+				cfhsi->ops);
+		if (ret) {
+			clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits);
+			netdev_warn(cfhsi->ndev,
+				"%s: can't read data: %d.\n",
+				__func__, ret);
+			break;
+		}
+
+		ret = 5 * HZ;
+		ret = wait_event_interruptible_timeout(cfhsi->flush_fifo_wait,
+			 !test_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits), ret);
+
+		if (ret < 0) {
+			netdev_warn(cfhsi->ndev,
+				"%s: can't wait for flush complete: %d.\n",
+				__func__, ret);
+			break;
+		} else if (!ret) {
+			ret = -ETIMEDOUT;
+			netdev_warn(cfhsi->ndev,
+				"%s: timeout waiting for flush complete.\n",
+				__func__);
+			break;
+		}
+	} while (1);
+
+	return ret;
+}
+
+static int cfhsi_tx_frm(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
+{
+	int nfrms = 0;
+	int pld_len = 0;
+	struct sk_buff *skb;
+	u8 *pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
+
+	skb = cfhsi_dequeue(cfhsi);
+	if (!skb)
+		return 0;
+
+	/* Clear offset. */
+	desc->offset = 0;
+
+	/* Check if we can embed a CAIF frame. */
+	if (skb->len < CFHSI_MAX_EMB_FRM_SZ) {
+		struct caif_payload_info *info;
+		int hpad;
+		int tpad;
+
+		/* Calculate needed head alignment and tail alignment. */
+		info = (struct caif_payload_info *)&skb->cb;
+
+		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
+		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
+
+		/* Check if frame still fits with added alignment. */
+		if ((skb->len + hpad + tpad) <= CFHSI_MAX_EMB_FRM_SZ) {
+			u8 *pemb = desc->emb_frm;
+			desc->offset = CFHSI_DESC_SHORT_SZ;
+			*pemb = (u8)(hpad - 1);
+			pemb += hpad;
+
+			/* Update network statistics. */
+			spin_lock_bh(&cfhsi->lock);
+			cfhsi->ndev->stats.tx_packets++;
+			cfhsi->ndev->stats.tx_bytes += skb->len;
+			cfhsi_update_aggregation_stats(cfhsi, skb, -1);
+			spin_unlock_bh(&cfhsi->lock);
+
+			/* Copy in embedded CAIF frame. */
+			skb_copy_bits(skb, 0, pemb, skb->len);
+
+			/* Consume the SKB */
+			consume_skb(skb);
+			skb = NULL;
+		}
+	}
+
+	/* Create payload CAIF frames. */
+	while (nfrms < CFHSI_MAX_PKTS) {
+		struct caif_payload_info *info;
+		int hpad;
+		int tpad;
+
+		if (!skb)
+			skb = cfhsi_dequeue(cfhsi);
+
+		if (!skb)
+			break;
+
+		/* Calculate needed head alignment and tail alignment. */
+		info = (struct caif_payload_info *)&skb->cb;
+
+		hpad = 1 + PAD_POW2((info->hdr_len + 1), cfhsi->cfg.head_align);
+		tpad = PAD_POW2((skb->len + hpad), cfhsi->cfg.tail_align);
+
+		/* Fill in CAIF frame length in descriptor. */
+		desc->cffrm_len[nfrms] = hpad + skb->len + tpad;
+
+		/* Fill head padding information. */
+		*pfrm = (u8)(hpad - 1);
+		pfrm += hpad;
+
+		/* Update network statistics. */
+		spin_lock_bh(&cfhsi->lock);
+		cfhsi->ndev->stats.tx_packets++;
+		cfhsi->ndev->stats.tx_bytes += skb->len;
+		cfhsi_update_aggregation_stats(cfhsi, skb, -1);
+		spin_unlock_bh(&cfhsi->lock);
+
+		/* Copy in CAIF frame. */
+		skb_copy_bits(skb, 0, pfrm, skb->len);
+
+		/* Update payload length. */
+		pld_len += desc->cffrm_len[nfrms];
+
+		/* Update frame pointer. */
+		pfrm += skb->len + tpad;
+
+		/* Consume the SKB */
+		consume_skb(skb);
+		skb = NULL;
+
+		/* Update number of frames. */
+		nfrms++;
+	}
+
+	/* Unused length fields should be zero-filled (according to SPEC). */
+	while (nfrms < CFHSI_MAX_PKTS) {
+		desc->cffrm_len[nfrms] = 0x0000;
+		nfrms++;
+	}
+
+	/* Check if we can piggy-back another descriptor. */
+	if (cfhsi_can_send_aggregate(cfhsi))
+		desc->header |= CFHSI_PIGGY_DESC;
+	else
+		desc->header &= ~CFHSI_PIGGY_DESC;
+
+	return CFHSI_DESC_SZ + pld_len;
+}
+
+static void cfhsi_start_tx(struct cfhsi *cfhsi)
+{
+	struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
+	int len, res;
+
+	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	do {
+		/* Create HSI frame. */
+		len = cfhsi_tx_frm(desc, cfhsi);
+		if (!len) {
+			spin_lock_bh(&cfhsi->lock);
+			if (unlikely(cfhsi_tx_queue_len(cfhsi))) {
+				spin_unlock_bh(&cfhsi->lock);
+				res = -EAGAIN;
+				continue;
+			}
+			cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
+			/* Start inactivity timer. */
+			mod_timer(&cfhsi->inactivity_timer,
+				jiffies + cfhsi->cfg.inactivity_timeout);
+			spin_unlock_bh(&cfhsi->lock);
+			break;
+		}
+
+		/* Set up new transfer. */
+		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
+		if (WARN_ON(res < 0))
+			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
+				__func__, res);
+	} while (res < 0);
+}
+
+static void cfhsi_tx_done(struct cfhsi *cfhsi)
+{
+	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	/*
+	 * Send flow on if flow off has been previously signalled
+	 * and number of packets is below low water mark.
+	 */
+	spin_lock_bh(&cfhsi->lock);
+	if (cfhsi->flow_off_sent &&
+			cfhsi_tx_queue_len(cfhsi) <= cfhsi->cfg.q_low_mark &&
+			cfhsi->cfdev.flowctrl) {
+
+		cfhsi->flow_off_sent = 0;
+		cfhsi->cfdev.flowctrl(cfhsi->ndev, ON);
+	}
+
+	if (cfhsi_can_send_aggregate(cfhsi)) {
+		spin_unlock_bh(&cfhsi->lock);
+		cfhsi_start_tx(cfhsi);
+	} else {
+		mod_timer(&cfhsi->aggregation_timer,
+			jiffies + cfhsi->cfg.aggregation_timeout);
+		spin_unlock_bh(&cfhsi->lock);
+	}
+
+	return;
+}
+
+static void cfhsi_tx_done_cb(struct cfhsi_cb_ops *cb_ops)
+{
+	struct cfhsi *cfhsi;
+
+	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+	cfhsi_tx_done(cfhsi);
+}
+
+static int cfhsi_rx_desc(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
+{
+	int xfer_sz = 0;
+	int nfrms = 0;
+	u16 *plen = NULL;
+	u8 *pfrm = NULL;
+
+	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
+			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
+		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
+			__func__);
+		return -EPROTO;
+	}
+
+	/* Check for embedded CAIF frame. */
+	if (desc->offset) {
+		struct sk_buff *skb;
+		int len = 0;
+		pfrm = ((u8 *)desc) + desc->offset;
+
+		/* Remove offset padding. */
+		pfrm += *pfrm + 1;
+
+		/* Read length of CAIF frame (little endian). */
+		len = *pfrm;
+		len |= ((*(pfrm+1)) << 8) & 0xFF00;
+		len += 2;	/* Add FCS fields. */
+
+		/* Sanity check length of CAIF frame. */
+		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
+			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
+				__func__);
+			return -EPROTO;
+		}
+
+		/* Allocate SKB (OK even in IRQ context). */
+		skb = alloc_skb(len + 1, GFP_ATOMIC);
+		if (!skb) {
+			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
+				__func__);
+			return -ENOMEM;
+		}
+		caif_assert(skb != NULL);
+
+		skb_put_data(skb, pfrm, len);
+
+		skb->protocol = htons(ETH_P_CAIF);
+		skb_reset_mac_header(skb);
+		skb->dev = cfhsi->ndev;
+
+		netif_rx_any_context(skb);
+
+		/* Update network statistics. */
+		cfhsi->ndev->stats.rx_packets++;
+		cfhsi->ndev->stats.rx_bytes += len;
+	}
+
+	/* Calculate transfer length. */
+	plen = desc->cffrm_len;
+	while (nfrms < CFHSI_MAX_PKTS && *plen) {
+		xfer_sz += *plen;
+		plen++;
+		nfrms++;
+	}
+
+	/* Check for piggy-backed descriptor. */
+	if (desc->header & CFHSI_PIGGY_DESC)
+		xfer_sz += CFHSI_DESC_SZ;
+
+	if ((xfer_sz % 4) || (xfer_sz > (CFHSI_BUF_SZ_RX - CFHSI_DESC_SZ))) {
+		netdev_err(cfhsi->ndev,
+				"%s: Invalid payload len: %d, ignored.\n",
+			__func__, xfer_sz);
+		return -EPROTO;
+	}
+	return xfer_sz;
+}
+
+static int cfhsi_rx_desc_len(struct cfhsi_desc *desc)
+{
+	int xfer_sz = 0;
+	int nfrms = 0;
+	u16 *plen;
+
+	if ((desc->header & ~CFHSI_PIGGY_DESC) ||
+			(desc->offset > CFHSI_MAX_EMB_FRM_SZ)) {
+
+		pr_err("Invalid descriptor. %x %x\n", desc->header,
+				desc->offset);
+		return -EPROTO;
+	}
+
+	/* Calculate transfer length. */
+	plen = desc->cffrm_len;
+	while (nfrms < CFHSI_MAX_PKTS && *plen) {
+		xfer_sz += *plen;
+		plen++;
+		nfrms++;
+	}
+
+	if (xfer_sz % 4) {
+		pr_err("Invalid payload len: %d, ignored.\n", xfer_sz);
+		return -EPROTO;
+	}
+	return xfer_sz;
+}
+
+static int cfhsi_rx_pld(struct cfhsi_desc *desc, struct cfhsi *cfhsi)
+{
+	int rx_sz = 0;
+	int nfrms = 0;
+	u16 *plen = NULL;
+	u8 *pfrm = NULL;
+
+	/* Sanity check header and offset. */
+	if (WARN_ON((desc->header & ~CFHSI_PIGGY_DESC) ||
+			(desc->offset > CFHSI_MAX_EMB_FRM_SZ))) {
+		netdev_err(cfhsi->ndev, "%s: Invalid descriptor.\n",
+			__func__);
+		return -EPROTO;
+	}
+
+	/* Set frame pointer to start of payload. */
+	pfrm = desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ;
+	plen = desc->cffrm_len;
+
+	/* Skip already processed frames. */
+	while (nfrms < cfhsi->rx_state.nfrms) {
+		pfrm += *plen;
+		rx_sz += *plen;
+		plen++;
+		nfrms++;
+	}
+
+	/* Parse payload. */
+	while (nfrms < CFHSI_MAX_PKTS && *plen) {
+		struct sk_buff *skb;
+		u8 *pcffrm = NULL;
+		int len;
+
+		/* CAIF frame starts after head padding. */
+		pcffrm = pfrm + *pfrm + 1;
+
+		/* Read length of CAIF frame (little endian). */
+		len = *pcffrm;
+		len |= ((*(pcffrm + 1)) << 8) & 0xFF00;
+		len += 2;	/* Add FCS fields. */
+
+		/* Sanity check length of CAIF frames. */
+		if (unlikely(len > CFHSI_MAX_CAIF_FRAME_SZ)) {
+			netdev_err(cfhsi->ndev, "%s: Invalid length.\n",
+				__func__);
+			return -EPROTO;
+		}
+
+		/* Allocate SKB (OK even in IRQ context). */
+		skb = alloc_skb(len + 1, GFP_ATOMIC);
+		if (!skb) {
+			netdev_err(cfhsi->ndev, "%s: Out of memory !\n",
+				__func__);
+			cfhsi->rx_state.nfrms = nfrms;
+			return -ENOMEM;
+		}
+		caif_assert(skb != NULL);
+
+		skb_put_data(skb, pcffrm, len);
+
+		skb->protocol = htons(ETH_P_CAIF);
+		skb_reset_mac_header(skb);
+		skb->dev = cfhsi->ndev;
+
+		netif_rx_any_context(skb);
+
+		/* Update network statistics. */
+		cfhsi->ndev->stats.rx_packets++;
+		cfhsi->ndev->stats.rx_bytes += len;
+
+		pfrm += *plen;
+		rx_sz += *plen;
+		plen++;
+		nfrms++;
+	}
+
+	return rx_sz;
+}
+
+static void cfhsi_rx_done(struct cfhsi *cfhsi)
+{
+	int res;
+	int desc_pld_len = 0, rx_len, rx_state;
+	struct cfhsi_desc *desc = NULL;
+	u8 *rx_ptr, *rx_buf;
+	struct cfhsi_desc *piggy_desc = NULL;
+
+	desc = (struct cfhsi_desc *)cfhsi->rx_buf;
+
+	netdev_dbg(cfhsi->ndev, "%s\n", __func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	/* Update inactivity timer if pending. */
+	spin_lock_bh(&cfhsi->lock);
+	mod_timer_pending(&cfhsi->inactivity_timer,
+			jiffies + cfhsi->cfg.inactivity_timeout);
+	spin_unlock_bh(&cfhsi->lock);
+
+	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
+		desc_pld_len = cfhsi_rx_desc_len(desc);
+
+		if (desc_pld_len < 0)
+			goto out_of_sync;
+
+		rx_buf = cfhsi->rx_buf;
+		rx_len = desc_pld_len;
+		if (desc_pld_len > 0 && (desc->header & CFHSI_PIGGY_DESC))
+			rx_len += CFHSI_DESC_SZ;
+		if (desc_pld_len == 0)
+			rx_buf = cfhsi->rx_flip_buf;
+	} else {
+		rx_buf = cfhsi->rx_flip_buf;
+
+		rx_len = CFHSI_DESC_SZ;
+		if (cfhsi->rx_state.pld_len > 0 &&
+				(desc->header & CFHSI_PIGGY_DESC)) {
+
+			piggy_desc = (struct cfhsi_desc *)
+				(desc->emb_frm + CFHSI_MAX_EMB_FRM_SZ +
+						cfhsi->rx_state.pld_len);
+
+			cfhsi->rx_state.piggy_desc = true;
+
+			/* Extract payload len from piggy-backed descriptor. */
+			desc_pld_len = cfhsi_rx_desc_len(piggy_desc);
+			if (desc_pld_len < 0)
+				goto out_of_sync;
+
+			if (desc_pld_len > 0) {
+				rx_len = desc_pld_len;
+				if (piggy_desc->header & CFHSI_PIGGY_DESC)
+					rx_len += CFHSI_DESC_SZ;
+			}
+
+			/*
+			 * Copy needed information from the piggy-backed
+			 * descriptor to the descriptor in the start.
+			 */
+			memcpy(rx_buf, (u8 *)piggy_desc,
+					CFHSI_DESC_SHORT_SZ);
+		}
+	}
+
+	if (desc_pld_len) {
+		rx_state = CFHSI_RX_STATE_PAYLOAD;
+		rx_ptr = rx_buf + CFHSI_DESC_SZ;
+	} else {
+		rx_state = CFHSI_RX_STATE_DESC;
+		rx_ptr = rx_buf;
+		rx_len = CFHSI_DESC_SZ;
+	}
+
+	/* Initiate next read */
+	if (test_bit(CFHSI_AWAKE, &cfhsi->bits)) {
+		/* Set up new transfer. */
+		netdev_dbg(cfhsi->ndev, "%s: Start RX.\n",
+				__func__);
+
+		res = cfhsi->ops->cfhsi_rx(rx_ptr, rx_len,
+				cfhsi->ops);
+		if (WARN_ON(res < 0)) {
+			netdev_err(cfhsi->ndev, "%s: RX error %d.\n",
+				__func__, res);
+			cfhsi->ndev->stats.rx_errors++;
+			cfhsi->ndev->stats.rx_dropped++;
+		}
+	}
+
+	if (cfhsi->rx_state.state == CFHSI_RX_STATE_DESC) {
+		/* Extract payload from descriptor */
+		if (cfhsi_rx_desc(desc, cfhsi) < 0)
+			goto out_of_sync;
+	} else {
+		/* Extract payload */
+		if (cfhsi_rx_pld(desc, cfhsi) < 0)
+			goto out_of_sync;
+		if (piggy_desc) {
+			/* Extract any payload in piggyback descriptor. */
+			if (cfhsi_rx_desc(piggy_desc, cfhsi) < 0)
+				goto out_of_sync;
+			/* Mark no embedded frame after extracting it */
+			piggy_desc->offset = 0;
+		}
+	}
+
+	/* Update state info */
+	memset(&cfhsi->rx_state, 0, sizeof(cfhsi->rx_state));
+	cfhsi->rx_state.state = rx_state;
+	cfhsi->rx_ptr = rx_ptr;
+	cfhsi->rx_len = rx_len;
+	cfhsi->rx_state.pld_len = desc_pld_len;
+	cfhsi->rx_state.piggy_desc = desc->header & CFHSI_PIGGY_DESC;
+
+	if (rx_buf != cfhsi->rx_buf)
+		swap(cfhsi->rx_buf, cfhsi->rx_flip_buf);
+	return;
+
+out_of_sync:
+	netdev_err(cfhsi->ndev, "%s: Out of sync.\n", __func__);
+	print_hex_dump_bytes("--> ", DUMP_PREFIX_NONE,
+			cfhsi->rx_buf, CFHSI_DESC_SZ);
+	schedule_work(&cfhsi->out_of_sync_work);
+}
+
+static void cfhsi_rx_slowpath(struct timer_list *t)
+{
+	struct cfhsi *cfhsi = from_timer(cfhsi, t, rx_slowpath_timer);
+
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	cfhsi_rx_done(cfhsi);
+}
+
+static void cfhsi_rx_done_cb(struct cfhsi_cb_ops *cb_ops)
+{
+	struct cfhsi *cfhsi;
+
+	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	if (test_and_clear_bit(CFHSI_FLUSH_FIFO, &cfhsi->bits))
+		wake_up_interruptible(&cfhsi->flush_fifo_wait);
+	else
+		cfhsi_rx_done(cfhsi);
+}
+
+static void cfhsi_wake_up(struct work_struct *work)
+{
+	struct cfhsi *cfhsi = NULL;
+	int res;
+	int len;
+	long ret;
+
+	cfhsi = container_of(work, struct cfhsi, wake_up_work);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	if (unlikely(test_bit(CFHSI_AWAKE, &cfhsi->bits))) {
+		/* It happenes when wakeup is requested by
+		 * both ends at the same time. */
+		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
+		clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
+		return;
+	}
+
+	/* Activate wake line. */
+	cfhsi->ops->cfhsi_wake_up(cfhsi->ops);
+
+	netdev_dbg(cfhsi->ndev, "%s: Start waiting.\n",
+		__func__);
+
+	/* Wait for acknowledge. */
+	ret = CFHSI_WAKE_TOUT;
+	ret = wait_event_interruptible_timeout(cfhsi->wake_up_wait,
+					test_and_clear_bit(CFHSI_WAKE_UP_ACK,
+							&cfhsi->bits), ret);
+	if (unlikely(ret < 0)) {
+		/* Interrupted by signal. */
+		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
+			__func__, ret);
+
+		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
+		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
+		return;
+	} else if (!ret) {
+		bool ca_wake = false;
+		size_t fifo_occupancy = 0;
+
+		/* Wakeup timeout */
+		netdev_dbg(cfhsi->ndev, "%s: Timeout.\n",
+			__func__);
+
+		/* Check FIFO to check if modem has sent something. */
+		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
+					&fifo_occupancy));
+
+		netdev_dbg(cfhsi->ndev, "%s: Bytes in FIFO: %u.\n",
+				__func__, (unsigned) fifo_occupancy);
+
+		/* Check if we misssed the interrupt. */
+		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
+							&ca_wake));
+
+		if (ca_wake) {
+			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
+				__func__);
+
+			/* Clear the CFHSI_WAKE_UP_ACK bit to prevent race. */
+			clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
+
+			/* Continue execution. */
+			goto wake_ack;
+		}
+
+		clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
+		cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
+		return;
+	}
+wake_ack:
+	netdev_dbg(cfhsi->ndev, "%s: Woken.\n",
+		__func__);
+
+	/* Clear power up bit. */
+	set_bit(CFHSI_AWAKE, &cfhsi->bits);
+	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
+
+	/* Resume read operation. */
+	netdev_dbg(cfhsi->ndev, "%s: Start RX.\n", __func__);
+	res = cfhsi->ops->cfhsi_rx(cfhsi->rx_ptr, cfhsi->rx_len, cfhsi->ops);
+
+	if (WARN_ON(res < 0))
+		netdev_err(cfhsi->ndev, "%s: RX err %d.\n", __func__, res);
+
+	/* Clear power up acknowledment. */
+	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
+
+	spin_lock_bh(&cfhsi->lock);
+
+	/* Resume transmit if queues are not empty. */
+	if (!cfhsi_tx_queue_len(cfhsi)) {
+		netdev_dbg(cfhsi->ndev, "%s: Peer wake, start timer.\n",
+			__func__);
+		/* Start inactivity timer. */
+		mod_timer(&cfhsi->inactivity_timer,
+				jiffies + cfhsi->cfg.inactivity_timeout);
+		spin_unlock_bh(&cfhsi->lock);
+		return;
+	}
+
+	netdev_dbg(cfhsi->ndev, "%s: Host wake.\n",
+		__func__);
+
+	spin_unlock_bh(&cfhsi->lock);
+
+	/* Create HSI frame. */
+	len = cfhsi_tx_frm((struct cfhsi_desc *)cfhsi->tx_buf, cfhsi);
+
+	if (likely(len > 0)) {
+		/* Set up new transfer. */
+		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
+		if (WARN_ON(res < 0)) {
+			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
+				__func__, res);
+			cfhsi_abort_tx(cfhsi);
+		}
+	} else {
+		netdev_err(cfhsi->ndev,
+				"%s: Failed to create HSI frame: %d.\n",
+				__func__, len);
+	}
+}
+
+static void cfhsi_wake_down(struct work_struct *work)
+{
+	long ret;
+	struct cfhsi *cfhsi = NULL;
+	size_t fifo_occupancy = 0;
+	int retry = CFHSI_WAKE_TOUT;
+
+	cfhsi = container_of(work, struct cfhsi, wake_down_work);
+	netdev_dbg(cfhsi->ndev, "%s.\n", __func__);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	/* Deactivate wake line. */
+	cfhsi->ops->cfhsi_wake_down(cfhsi->ops);
+
+	/* Wait for acknowledge. */
+	ret = CFHSI_WAKE_TOUT;
+	ret = wait_event_interruptible_timeout(cfhsi->wake_down_wait,
+					test_and_clear_bit(CFHSI_WAKE_DOWN_ACK,
+							&cfhsi->bits), ret);
+	if (ret < 0) {
+		/* Interrupted by signal. */
+		netdev_err(cfhsi->ndev, "%s: Signalled: %ld.\n",
+			__func__, ret);
+		return;
+	} else if (!ret) {
+		bool ca_wake = true;
+
+		/* Timeout */
+		netdev_err(cfhsi->ndev, "%s: Timeout.\n", __func__);
+
+		/* Check if we misssed the interrupt. */
+		WARN_ON(cfhsi->ops->cfhsi_get_peer_wake(cfhsi->ops,
+							&ca_wake));
+		if (!ca_wake)
+			netdev_err(cfhsi->ndev, "%s: CA Wake missed !.\n",
+				__func__);
+	}
+
+	/* Check FIFO occupancy. */
+	while (retry) {
+		WARN_ON(cfhsi->ops->cfhsi_fifo_occupancy(cfhsi->ops,
+							&fifo_occupancy));
+
+		if (!fifo_occupancy)
+			break;
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(1);
+		retry--;
+	}
+
+	if (!retry)
+		netdev_err(cfhsi->ndev, "%s: FIFO Timeout.\n", __func__);
+
+	/* Clear AWAKE condition. */
+	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
+
+	/* Cancel pending RX requests. */
+	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
+}
+
+static void cfhsi_out_of_sync(struct work_struct *work)
+{
+	struct cfhsi *cfhsi = NULL;
+
+	cfhsi = container_of(work, struct cfhsi, out_of_sync_work);
+
+	rtnl_lock();
+	dev_close(cfhsi->ndev);
+	rtnl_unlock();
+}
+
+static void cfhsi_wake_up_cb(struct cfhsi_cb_ops *cb_ops)
+{
+	struct cfhsi *cfhsi = NULL;
+
+	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	set_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
+	wake_up_interruptible(&cfhsi->wake_up_wait);
+
+	if (test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))
+		return;
+
+	/* Schedule wake up work queue if the peer initiates. */
+	if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
+		queue_work(cfhsi->wq, &cfhsi->wake_up_work);
+}
+
+static void cfhsi_wake_down_cb(struct cfhsi_cb_ops *cb_ops)
+{
+	struct cfhsi *cfhsi = NULL;
+
+	cfhsi = container_of(cb_ops, struct cfhsi, cb_ops);
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	/* Initiating low power is only permitted by the host (us). */
+	set_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
+	wake_up_interruptible(&cfhsi->wake_down_wait);
+}
+
+static void cfhsi_aggregation_tout(struct timer_list *t)
+{
+	struct cfhsi *cfhsi = from_timer(cfhsi, t, aggregation_timer);
+
+	netdev_dbg(cfhsi->ndev, "%s.\n",
+		__func__);
+
+	cfhsi_start_tx(cfhsi);
+}
+
+static netdev_tx_t cfhsi_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct cfhsi *cfhsi = NULL;
+	int start_xfer = 0;
+	int timer_active;
+	int prio;
+
+	if (!dev)
+		return -EINVAL;
+
+	cfhsi = netdev_priv(dev);
+
+	switch (skb->priority) {
+	case TC_PRIO_BESTEFFORT:
+	case TC_PRIO_FILLER:
+	case TC_PRIO_BULK:
+		prio = CFHSI_PRIO_BEBK;
+		break;
+	case TC_PRIO_INTERACTIVE_BULK:
+		prio = CFHSI_PRIO_VI;
+		break;
+	case TC_PRIO_INTERACTIVE:
+		prio = CFHSI_PRIO_VO;
+		break;
+	case TC_PRIO_CONTROL:
+	default:
+		prio = CFHSI_PRIO_CTL;
+		break;
+	}
+
+	spin_lock_bh(&cfhsi->lock);
+
+	/* Update aggregation statistics  */
+	cfhsi_update_aggregation_stats(cfhsi, skb, 1);
+
+	/* Queue the SKB */
+	skb_queue_tail(&cfhsi->qhead[prio], skb);
+
+	/* Sanity check; xmit should not be called after unregister_netdev */
+	if (WARN_ON(test_bit(CFHSI_SHUTDOWN, &cfhsi->bits))) {
+		spin_unlock_bh(&cfhsi->lock);
+		cfhsi_abort_tx(cfhsi);
+		return -EINVAL;
+	}
+
+	/* Send flow off if number of packets is above high water mark. */
+	if (!cfhsi->flow_off_sent &&
+		cfhsi_tx_queue_len(cfhsi) > cfhsi->cfg.q_high_mark &&
+		cfhsi->cfdev.flowctrl) {
+		cfhsi->flow_off_sent = 1;
+		cfhsi->cfdev.flowctrl(cfhsi->ndev, OFF);
+	}
+
+	if (cfhsi->tx_state == CFHSI_TX_STATE_IDLE) {
+		cfhsi->tx_state = CFHSI_TX_STATE_XFER;
+		start_xfer = 1;
+	}
+
+	if (!start_xfer) {
+		/* Send aggregate if it is possible */
+		bool aggregate_ready =
+			cfhsi_can_send_aggregate(cfhsi) &&
+			del_timer(&cfhsi->aggregation_timer) > 0;
+		spin_unlock_bh(&cfhsi->lock);
+		if (aggregate_ready)
+			cfhsi_start_tx(cfhsi);
+		return NETDEV_TX_OK;
+	}
+
+	/* Delete inactivity timer if started. */
+	timer_active = del_timer_sync(&cfhsi->inactivity_timer);
+
+	spin_unlock_bh(&cfhsi->lock);
+
+	if (timer_active) {
+		struct cfhsi_desc *desc = (struct cfhsi_desc *)cfhsi->tx_buf;
+		int len;
+		int res;
+
+		/* Create HSI frame. */
+		len = cfhsi_tx_frm(desc, cfhsi);
+		WARN_ON(!len);
+
+		/* Set up new transfer. */
+		res = cfhsi->ops->cfhsi_tx(cfhsi->tx_buf, len, cfhsi->ops);
+		if (WARN_ON(res < 0)) {
+			netdev_err(cfhsi->ndev, "%s: TX error %d.\n",
+				__func__, res);
+			cfhsi_abort_tx(cfhsi);
+		}
+	} else {
+		/* Schedule wake up work queue if the we initiate. */
+		if (!test_and_set_bit(CFHSI_WAKE_UP, &cfhsi->bits))
+			queue_work(cfhsi->wq, &cfhsi->wake_up_work);
+	}
+
+	return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops cfhsi_netdevops;
+
+static void cfhsi_setup(struct net_device *dev)
+{
+	int i;
+	struct cfhsi *cfhsi = netdev_priv(dev);
+	dev->features = 0;
+	dev->type = ARPHRD_CAIF;
+	dev->flags = IFF_POINTOPOINT | IFF_NOARP;
+	dev->mtu = CFHSI_MAX_CAIF_FRAME_SZ;
+	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->needs_free_netdev = true;
+	dev->netdev_ops = &cfhsi_netdevops;
+	for (i = 0; i < CFHSI_PRIO_LAST; ++i)
+		skb_queue_head_init(&cfhsi->qhead[i]);
+	cfhsi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
+	cfhsi->cfdev.use_frag = false;
+	cfhsi->cfdev.use_stx = false;
+	cfhsi->cfdev.use_fcs = false;
+	cfhsi->ndev = dev;
+	cfhsi->cfg = hsi_default_config;
+}
+
+static int cfhsi_open(struct net_device *ndev)
+{
+	struct cfhsi *cfhsi = netdev_priv(ndev);
+	int res;
+
+	clear_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
+
+	/* Initialize state vaiables. */
+	cfhsi->tx_state = CFHSI_TX_STATE_IDLE;
+	cfhsi->rx_state.state = CFHSI_RX_STATE_DESC;
+
+	/* Set flow info */
+	cfhsi->flow_off_sent = 0;
+
+	/*
+	 * Allocate a TX buffer with the size of a HSI packet descriptors
+	 * and the necessary room for CAIF payload frames.
+	 */
+	cfhsi->tx_buf = kzalloc(CFHSI_BUF_SZ_TX, GFP_KERNEL);
+	if (!cfhsi->tx_buf) {
+		res = -ENODEV;
+		goto err_alloc_tx;
+	}
+
+	/*
+	 * Allocate a RX buffer with the size of two HSI packet descriptors and
+	 * the necessary room for CAIF payload frames.
+	 */
+	cfhsi->rx_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
+	if (!cfhsi->rx_buf) {
+		res = -ENODEV;
+		goto err_alloc_rx;
+	}
+
+	cfhsi->rx_flip_buf = kzalloc(CFHSI_BUF_SZ_RX, GFP_KERNEL);
+	if (!cfhsi->rx_flip_buf) {
+		res = -ENODEV;
+		goto err_alloc_rx_flip;
+	}
+
+	/* Initialize aggregation timeout */
+	cfhsi->cfg.aggregation_timeout = hsi_default_config.aggregation_timeout;
+
+	/* Initialize recieve vaiables. */
+	cfhsi->rx_ptr = cfhsi->rx_buf;
+	cfhsi->rx_len = CFHSI_DESC_SZ;
+
+	/* Initialize spin locks. */
+	spin_lock_init(&cfhsi->lock);
+
+	/* Set up the driver. */
+	cfhsi->cb_ops.tx_done_cb = cfhsi_tx_done_cb;
+	cfhsi->cb_ops.rx_done_cb = cfhsi_rx_done_cb;
+	cfhsi->cb_ops.wake_up_cb = cfhsi_wake_up_cb;
+	cfhsi->cb_ops.wake_down_cb = cfhsi_wake_down_cb;
+
+	/* Initialize the work queues. */
+	INIT_WORK(&cfhsi->wake_up_work, cfhsi_wake_up);
+	INIT_WORK(&cfhsi->wake_down_work, cfhsi_wake_down);
+	INIT_WORK(&cfhsi->out_of_sync_work, cfhsi_out_of_sync);
+
+	/* Clear all bit fields. */
+	clear_bit(CFHSI_WAKE_UP_ACK, &cfhsi->bits);
+	clear_bit(CFHSI_WAKE_DOWN_ACK, &cfhsi->bits);
+	clear_bit(CFHSI_WAKE_UP, &cfhsi->bits);
+	clear_bit(CFHSI_AWAKE, &cfhsi->bits);
+
+	/* Create work thread. */
+	cfhsi->wq = alloc_ordered_workqueue(cfhsi->ndev->name, WQ_MEM_RECLAIM);
+	if (!cfhsi->wq) {
+		netdev_err(cfhsi->ndev, "%s: Failed to create work queue.\n",
+			__func__);
+		res = -ENODEV;
+		goto err_create_wq;
+	}
+
+	/* Initialize wait queues. */
+	init_waitqueue_head(&cfhsi->wake_up_wait);
+	init_waitqueue_head(&cfhsi->wake_down_wait);
+	init_waitqueue_head(&cfhsi->flush_fifo_wait);
+
+	/* Setup the inactivity timer. */
+	timer_setup(&cfhsi->inactivity_timer, cfhsi_inactivity_tout, 0);
+	/* Setup the slowpath RX timer. */
+	timer_setup(&cfhsi->rx_slowpath_timer, cfhsi_rx_slowpath, 0);
+	/* Setup the aggregation timer. */
+	timer_setup(&cfhsi->aggregation_timer, cfhsi_aggregation_tout, 0);
+
+	/* Activate HSI interface. */
+	res = cfhsi->ops->cfhsi_up(cfhsi->ops);
+	if (res) {
+		netdev_err(cfhsi->ndev,
+			"%s: can't activate HSI interface: %d.\n",
+			__func__, res);
+		goto err_activate;
+	}
+
+	/* Flush FIFO */
+	res = cfhsi_flush_fifo(cfhsi);
+	if (res) {
+		netdev_err(cfhsi->ndev, "%s: Can't flush FIFO: %d.\n",
+			__func__, res);
+		goto err_net_reg;
+	}
+	return res;
+
+ err_net_reg:
+	cfhsi->ops->cfhsi_down(cfhsi->ops);
+ err_activate:
+	destroy_workqueue(cfhsi->wq);
+ err_create_wq:
+	kfree(cfhsi->rx_flip_buf);
+ err_alloc_rx_flip:
+	kfree(cfhsi->rx_buf);
+ err_alloc_rx:
+	kfree(cfhsi->tx_buf);
+ err_alloc_tx:
+	return res;
+}
+
+static int cfhsi_close(struct net_device *ndev)
+{
+	struct cfhsi *cfhsi = netdev_priv(ndev);
+	u8 *tx_buf, *rx_buf, *flip_buf;
+
+	/* going to shutdown driver */
+	set_bit(CFHSI_SHUTDOWN, &cfhsi->bits);
+
+	/* Delete timers if pending */
+	del_timer_sync(&cfhsi->inactivity_timer);
+	del_timer_sync(&cfhsi->rx_slowpath_timer);
+	del_timer_sync(&cfhsi->aggregation_timer);
+
+	/* Cancel pending RX request (if any) */
+	cfhsi->ops->cfhsi_rx_cancel(cfhsi->ops);
+
+	/* Destroy workqueue */
+	destroy_workqueue(cfhsi->wq);
+
+	/* Store bufferes: will be freed later. */
+	tx_buf = cfhsi->tx_buf;
+	rx_buf = cfhsi->rx_buf;
+	flip_buf = cfhsi->rx_flip_buf;
+	/* Flush transmit queues. */
+	cfhsi_abort_tx(cfhsi);
+
+	/* Deactivate interface */
+	cfhsi->ops->cfhsi_down(cfhsi->ops);
+
+	/* Free buffers. */
+	kfree(tx_buf);
+	kfree(rx_buf);
+	kfree(flip_buf);
+	return 0;
+}
+
+static void cfhsi_uninit(struct net_device *dev)
+{
+	struct cfhsi *cfhsi = netdev_priv(dev);
+	ASSERT_RTNL();
+	symbol_put(cfhsi_get_device);
+	list_del(&cfhsi->list);
+}
+
+static const struct net_device_ops cfhsi_netdevops = {
+	.ndo_uninit = cfhsi_uninit,
+	.ndo_open = cfhsi_open,
+	.ndo_stop = cfhsi_close,
+	.ndo_start_xmit = cfhsi_xmit
+};
+
+static void cfhsi_netlink_parms(struct nlattr *data[], struct cfhsi *cfhsi)
+{
+	int i;
+
+	if (!data) {
+		pr_debug("no params data found\n");
+		return;
+	}
+
+	i = __IFLA_CAIF_HSI_INACTIVITY_TOUT;
+	/*
+	 * Inactivity timeout in millisecs. Lowest possible value is 1,
+	 * and highest possible is NEXT_TIMER_MAX_DELTA.
+	 */
+	if (data[i]) {
+		u32 inactivity_timeout = nla_get_u32(data[i]);
+		/* Pre-calculate inactivity timeout. */
+		cfhsi->cfg.inactivity_timeout =	inactivity_timeout * HZ / 1000;
+		if (cfhsi->cfg.inactivity_timeout == 0)
+			cfhsi->cfg.inactivity_timeout = 1;
+		else if (cfhsi->cfg.inactivity_timeout > NEXT_TIMER_MAX_DELTA)
+			cfhsi->cfg.inactivity_timeout = NEXT_TIMER_MAX_DELTA;
+	}
+
+	i = __IFLA_CAIF_HSI_AGGREGATION_TOUT;
+	if (data[i])
+		cfhsi->cfg.aggregation_timeout = nla_get_u32(data[i]);
+
+	i = __IFLA_CAIF_HSI_HEAD_ALIGN;
+	if (data[i])
+		cfhsi->cfg.head_align = nla_get_u32(data[i]);
+
+	i = __IFLA_CAIF_HSI_TAIL_ALIGN;
+	if (data[i])
+		cfhsi->cfg.tail_align = nla_get_u32(data[i]);
+
+	i = __IFLA_CAIF_HSI_QHIGH_WATERMARK;
+	if (data[i])
+		cfhsi->cfg.q_high_mark = nla_get_u32(data[i]);
+
+	i = __IFLA_CAIF_HSI_QLOW_WATERMARK;
+	if (data[i])
+		cfhsi->cfg.q_low_mark = nla_get_u32(data[i]);
+}
+
+static int caif_hsi_changelink(struct net_device *dev, struct nlattr *tb[],
+			       struct nlattr *data[],
+			       struct netlink_ext_ack *extack)
+{
+	cfhsi_netlink_parms(data, netdev_priv(dev));
+	netdev_state_change(dev);
+	return 0;
+}
+
+static const struct nla_policy caif_hsi_policy[__IFLA_CAIF_HSI_MAX + 1] = {
+	[__IFLA_CAIF_HSI_INACTIVITY_TOUT] = { .type = NLA_U32, .len = 4 },
+	[__IFLA_CAIF_HSI_AGGREGATION_TOUT] = { .type = NLA_U32, .len = 4 },
+	[__IFLA_CAIF_HSI_HEAD_ALIGN] = { .type = NLA_U32, .len = 4 },
+	[__IFLA_CAIF_HSI_TAIL_ALIGN] = { .type = NLA_U32, .len = 4 },
+	[__IFLA_CAIF_HSI_QHIGH_WATERMARK] = { .type = NLA_U32, .len = 4 },
+	[__IFLA_CAIF_HSI_QLOW_WATERMARK] = { .type = NLA_U32, .len = 4 },
+};
+
+static size_t caif_hsi_get_size(const struct net_device *dev)
+{
+	int i;
+	size_t s = 0;
+	for (i = __IFLA_CAIF_HSI_UNSPEC + 1; i < __IFLA_CAIF_HSI_MAX; i++)
+		s += nla_total_size(caif_hsi_policy[i].len);
+	return s;
+}
+
+static int caif_hsi_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+	struct cfhsi *cfhsi = netdev_priv(dev);
+
+	if (nla_put_u32(skb, __IFLA_CAIF_HSI_INACTIVITY_TOUT,
+			cfhsi->cfg.inactivity_timeout) ||
+	    nla_put_u32(skb, __IFLA_CAIF_HSI_AGGREGATION_TOUT,
+			cfhsi->cfg.aggregation_timeout) ||
+	    nla_put_u32(skb, __IFLA_CAIF_HSI_HEAD_ALIGN,
+			cfhsi->cfg.head_align) ||
+	    nla_put_u32(skb, __IFLA_CAIF_HSI_TAIL_ALIGN,
+			cfhsi->cfg.tail_align) ||
+	    nla_put_u32(skb, __IFLA_CAIF_HSI_QHIGH_WATERMARK,
+			cfhsi->cfg.q_high_mark) ||
+	    nla_put_u32(skb, __IFLA_CAIF_HSI_QLOW_WATERMARK,
+			cfhsi->cfg.q_low_mark))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static int caif_hsi_newlink(struct net *src_net, struct net_device *dev,
+			    struct nlattr *tb[], struct nlattr *data[],
+			    struct netlink_ext_ack *extack)
+{
+	struct cfhsi *cfhsi = NULL;
+	struct cfhsi_ops *(*get_ops)(void);
+
+	ASSERT_RTNL();
+
+	cfhsi = netdev_priv(dev);
+	cfhsi_netlink_parms(data, cfhsi);
+
+	get_ops = symbol_get(cfhsi_get_ops);
+	if (!get_ops) {
+		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
+		return -ENODEV;
+	}
+
+	/* Assign the HSI device. */
+	cfhsi->ops = (*get_ops)();
+	if (!cfhsi->ops) {
+		pr_err("%s: failed to get the cfhsi_ops\n", __func__);
+		goto err;
+	}
+
+	/* Assign the driver to this HSI device. */
+	cfhsi->ops->cb_ops = &cfhsi->cb_ops;
+	if (register_netdevice(dev)) {
+		pr_warn("%s: caif_hsi device registration failed\n", __func__);
+		goto err;
+	}
+	/* Add CAIF HSI device to list. */
+	list_add_tail(&cfhsi->list, &cfhsi_list);
+
+	return 0;
+err:
+	symbol_put(cfhsi_get_ops);
+	return -ENODEV;
+}
+
+static struct rtnl_link_ops caif_hsi_link_ops __read_mostly = {
+	.kind		= "cfhsi",
+	.priv_size	= sizeof(struct cfhsi),
+	.setup		= cfhsi_setup,
+	.maxtype	= __IFLA_CAIF_HSI_MAX,
+	.policy	= caif_hsi_policy,
+	.newlink	= caif_hsi_newlink,
+	.changelink	= caif_hsi_changelink,
+	.get_size	= caif_hsi_get_size,
+	.fill_info	= caif_hsi_fill_info,
+};
+
+static void __exit cfhsi_exit_module(void)
+{
+	struct list_head *list_node;
+	struct list_head *n;
+	struct cfhsi *cfhsi;
+
+	rtnl_link_unregister(&caif_hsi_link_ops);
+
+	rtnl_lock();
+	list_for_each_safe(list_node, n, &cfhsi_list) {
+		cfhsi = list_entry(list_node, struct cfhsi, list);
+		unregister_netdevice(cfhsi->ndev);
+	}
+	rtnl_unlock();
+}
+
+static int __init cfhsi_init_module(void)
+{
+	return rtnl_link_register(&caif_hsi_link_ops);
+}
+
+module_init(cfhsi_init_module);
+module_exit(cfhsi_exit_module);