Renesas Ethernet AVB PTP clock driver

Ethernet AVB device includes the gPTP  timer, so we can implement a PTP clock
driver.  We're doing that in a separate file, with  the main Ethernet driver
calling the PTP driver's [de]initialization and interrupt handler functions.
Unfortunately, the clock seems tightly coupled with the AVB-DMAC, so when that
one leaves the operation mode, we have to unregister the PTP clock... :-(

Based on the original patches by Masaru Nagai.

Signed-off-by: Masaru Nagai <masaru.nagai.vx@renesas.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1824 insertions, 0 deletions

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
new file mode 100644
index 000000000000..fd9745714d90
--- /dev/null
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -0,0 +1,1824 @@
+/* Renesas Ethernet AVB device driver
+ *
+ * Copyright (C) 2014-2015 Renesas Electronics Corporation
+ * Copyright (C) 2015 Renesas Solutions Corp.
+ * Copyright (C) 2015 Cogent Embedded, Inc. <source@cogentembedded.com>
+ *
+ * Based on the SuperH Ethernet driver
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/cache.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/if_vlan.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/net_tstamp.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include "ravb.h"
+
+#define RAVB_DEF_MSG_ENABLE \
+		(NETIF_MSG_LINK	  | \
+		 NETIF_MSG_TIMER  | \
+		 NETIF_MSG_RX_ERR | \
+		 NETIF_MSG_TX_ERR)
+
+int ravb_wait(struct net_device *ndev, enum ravb_reg reg, u32 mask, u32 value)
+{
+	int i;
+
+	for (i = 0; i < 10000; i++) {
+		if ((ravb_read(ndev, reg) & mask) == value)
+			return 0;
+		udelay(10);
+	}
+	return -ETIMEDOUT;
+}
+
+static int ravb_config(struct net_device *ndev)
+{
+	int error;
+
+	/* Set config mode */
+	ravb_write(ndev, (ravb_read(ndev, CCC) & ~CCC_OPC) | CCC_OPC_CONFIG,
+		   CCC);
+	/* Check if the operating mode is changed to the config mode */
+	error = ravb_wait(ndev, CSR, CSR_OPS, CSR_OPS_CONFIG);
+	if (error)
+		netdev_err(ndev, "failed to switch device to config mode\n");
+
+	return error;
+}
+
+static void ravb_set_duplex(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	u32 ecmr = ravb_read(ndev, ECMR);
+
+	if (priv->duplex)	/* Full */
+		ecmr |=  ECMR_DM;
+	else			/* Half */
+		ecmr &= ~ECMR_DM;
+	ravb_write(ndev, ecmr, ECMR);
+}
+
+static void ravb_set_rate(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	switch (priv->speed) {
+	case 100:		/* 100BASE */
+		ravb_write(ndev, GECMR_SPEED_100, GECMR);
+		break;
+	case 1000:		/* 1000BASE */
+		ravb_write(ndev, GECMR_SPEED_1000, GECMR);
+		break;
+	default:
+		break;
+	}
+}
+
+static void ravb_set_buffer_align(struct sk_buff *skb)
+{
+	u32 reserve = (unsigned long)skb->data & (RAVB_ALIGN - 1);
+
+	if (reserve)
+		skb_reserve(skb, RAVB_ALIGN - reserve);
+}
+
+/* Get MAC address from the MAC address registers
+ *
+ * Ethernet AVB device doesn't have ROM for MAC address.
+ * This function gets the MAC address that was used by a bootloader.
+ */
+static void ravb_read_mac_address(struct net_device *ndev, const u8 *mac)
+{
+	if (mac) {
+		ether_addr_copy(ndev->dev_addr, mac);
+	} else {
+		ndev->dev_addr[0] = (ravb_read(ndev, MAHR) >> 24);
+		ndev->dev_addr[1] = (ravb_read(ndev, MAHR) >> 16) & 0xFF;
+		ndev->dev_addr[2] = (ravb_read(ndev, MAHR) >> 8) & 0xFF;
+		ndev->dev_addr[3] = (ravb_read(ndev, MAHR) >> 0) & 0xFF;
+		ndev->dev_addr[4] = (ravb_read(ndev, MALR) >> 8) & 0xFF;
+		ndev->dev_addr[5] = (ravb_read(ndev, MALR) >> 0) & 0xFF;
+	}
+}
+
+static void ravb_mdio_ctrl(struct mdiobb_ctrl *ctrl, u32 mask, int set)
+{
+	struct ravb_private *priv = container_of(ctrl, struct ravb_private,
+						 mdiobb);
+	u32 pir = ravb_read(priv->ndev, PIR);
+
+	if (set)
+		pir |=  mask;
+	else
+		pir &= ~mask;
+	ravb_write(priv->ndev, pir, PIR);
+}
+
+/* MDC pin control */
+static void ravb_set_mdc(struct mdiobb_ctrl *ctrl, int level)
+{
+	ravb_mdio_ctrl(ctrl, PIR_MDC, level);
+}
+
+/* Data I/O pin control */
+static void ravb_set_mdio_dir(struct mdiobb_ctrl *ctrl, int output)
+{
+	ravb_mdio_ctrl(ctrl, PIR_MMD, output);
+}
+
+/* Set data bit */
+static void ravb_set_mdio_data(struct mdiobb_ctrl *ctrl, int value)
+{
+	ravb_mdio_ctrl(ctrl, PIR_MDO, value);
+}
+
+/* Get data bit */
+static int ravb_get_mdio_data(struct mdiobb_ctrl *ctrl)
+{
+	struct ravb_private *priv = container_of(ctrl, struct ravb_private,
+						 mdiobb);
+
+	return (ravb_read(priv->ndev, PIR) & PIR_MDI) != 0;
+}
+
+/* MDIO bus control struct */
+static struct mdiobb_ops bb_ops = {
+	.owner = THIS_MODULE,
+	.set_mdc = ravb_set_mdc,
+	.set_mdio_dir = ravb_set_mdio_dir,
+	.set_mdio_data = ravb_set_mdio_data,
+	.get_mdio_data = ravb_get_mdio_data,
+};
+
+/* Free skb's and DMA buffers for Ethernet AVB */
+static void ravb_ring_free(struct net_device *ndev, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int ring_size;
+	int i;
+
+	/* Free RX skb ringbuffer */
+	if (priv->rx_skb[q]) {
+		for (i = 0; i < priv->num_rx_ring[q]; i++)
+			dev_kfree_skb(priv->rx_skb[q][i]);
+	}
+	kfree(priv->rx_skb[q]);
+	priv->rx_skb[q] = NULL;
+
+	/* Free TX skb ringbuffer */
+	if (priv->tx_skb[q]) {
+		for (i = 0; i < priv->num_tx_ring[q]; i++)
+			dev_kfree_skb(priv->tx_skb[q][i]);
+	}
+	kfree(priv->tx_skb[q]);
+	priv->tx_skb[q] = NULL;
+
+	/* Free aligned TX buffers */
+	if (priv->tx_buffers[q]) {
+		for (i = 0; i < priv->num_tx_ring[q]; i++)
+			kfree(priv->tx_buffers[q][i]);
+	}
+	kfree(priv->tx_buffers[q]);
+	priv->tx_buffers[q] = NULL;
+
+	if (priv->rx_ring[q]) {
+		ring_size = sizeof(struct ravb_ex_rx_desc) *
+			    (priv->num_rx_ring[q] + 1);
+		dma_free_coherent(NULL, ring_size, priv->rx_ring[q],
+				  priv->rx_desc_dma[q]);
+		priv->rx_ring[q] = NULL;
+	}
+
+	if (priv->tx_ring[q]) {
+		ring_size = sizeof(struct ravb_tx_desc) *
+			    (priv->num_tx_ring[q] + 1);
+		dma_free_coherent(NULL, ring_size, priv->tx_ring[q],
+				  priv->tx_desc_dma[q]);
+		priv->tx_ring[q] = NULL;
+	}
+}
+
+/* Format skb and descriptor buffer for Ethernet AVB */
+static void ravb_ring_format(struct net_device *ndev, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct ravb_ex_rx_desc *rx_desc = NULL;
+	struct ravb_tx_desc *tx_desc = NULL;
+	struct ravb_desc *desc = NULL;
+	int rx_ring_size = sizeof(*rx_desc) * priv->num_rx_ring[q];
+	int tx_ring_size = sizeof(*tx_desc) * priv->num_tx_ring[q];
+	struct sk_buff *skb;
+	dma_addr_t dma_addr;
+	void *buffer;
+	int i;
+
+	priv->cur_rx[q] = 0;
+	priv->cur_tx[q] = 0;
+	priv->dirty_rx[q] = 0;
+	priv->dirty_tx[q] = 0;
+
+	memset(priv->rx_ring[q], 0, rx_ring_size);
+	/* Build RX ring buffer */
+	for (i = 0; i < priv->num_rx_ring[q]; i++) {
+		priv->rx_skb[q][i] = NULL;
+		skb = netdev_alloc_skb(ndev, PKT_BUF_SZ + RAVB_ALIGN - 1);
+		if (!skb)
+			break;
+		ravb_set_buffer_align(skb);
+		/* RX descriptor */
+		rx_desc = &priv->rx_ring[q][i];
+		/* The size of the buffer should be on 16-byte boundary. */
+		rx_desc->ds_cc = cpu_to_le16(ALIGN(PKT_BUF_SZ, 16));
+		dma_addr = dma_map_single(&ndev->dev, skb->data,
+					  ALIGN(PKT_BUF_SZ, 16),
+					  DMA_FROM_DEVICE);
+		if (dma_mapping_error(&ndev->dev, dma_addr)) {
+			dev_kfree_skb(skb);
+			break;
+		}
+		priv->rx_skb[q][i] = skb;
+		rx_desc->dptr = cpu_to_le32(dma_addr);
+		rx_desc->die_dt = DT_FEMPTY;
+	}
+	rx_desc = &priv->rx_ring[q][i];
+	rx_desc->dptr = cpu_to_le32((u32)priv->rx_desc_dma[q]);
+	rx_desc->die_dt = DT_LINKFIX; /* type */
+	priv->dirty_rx[q] = (u32)(i - priv->num_rx_ring[q]);
+
+	memset(priv->tx_ring[q], 0, tx_ring_size);
+	/* Build TX ring buffer */
+	for (i = 0; i < priv->num_tx_ring[q]; i++) {
+		priv->tx_skb[q][i] = NULL;
+		priv->tx_buffers[q][i] = NULL;
+		buffer = kmalloc(PKT_BUF_SZ + RAVB_ALIGN - 1, GFP_KERNEL);
+		if (!buffer)
+			break;
+		/* Aligned TX buffer */
+		priv->tx_buffers[q][i] = buffer;
+		tx_desc = &priv->tx_ring[q][i];
+		tx_desc->die_dt = DT_EEMPTY;
+	}
+	tx_desc = &priv->tx_ring[q][i];
+	tx_desc->dptr = cpu_to_le32((u32)priv->tx_desc_dma[q]);
+	tx_desc->die_dt = DT_LINKFIX; /* type */
+
+	/* RX descriptor base address for best effort */
+	desc = &priv->desc_bat[RX_QUEUE_OFFSET + q];
+	desc->die_dt = DT_LINKFIX; /* type */
+	desc->dptr = cpu_to_le32((u32)priv->rx_desc_dma[q]);
+
+	/* TX descriptor base address for best effort */
+	desc = &priv->desc_bat[q];
+	desc->die_dt = DT_LINKFIX; /* type */
+	desc->dptr = cpu_to_le32((u32)priv->tx_desc_dma[q]);
+}
+
+/* Init skb and descriptor buffer for Ethernet AVB */
+static int ravb_ring_init(struct net_device *ndev, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int ring_size;
+
+	/* Allocate RX and TX skb rings */
+	priv->rx_skb[q] = kcalloc(priv->num_rx_ring[q],
+				  sizeof(*priv->rx_skb[q]), GFP_KERNEL);
+	priv->tx_skb[q] = kcalloc(priv->num_tx_ring[q],
+				  sizeof(*priv->tx_skb[q]), GFP_KERNEL);
+	if (!priv->rx_skb[q] || !priv->tx_skb[q])
+		goto error;
+
+	/* Allocate rings for the aligned buffers */
+	priv->tx_buffers[q] = kcalloc(priv->num_tx_ring[q],
+				      sizeof(*priv->tx_buffers[q]), GFP_KERNEL);
+	if (!priv->tx_buffers[q])
+		goto error;
+
+	/* Allocate all RX descriptors. */
+	ring_size = sizeof(struct ravb_ex_rx_desc) * (priv->num_rx_ring[q] + 1);
+	priv->rx_ring[q] = dma_alloc_coherent(NULL, ring_size,
+					      &priv->rx_desc_dma[q],
+					      GFP_KERNEL);
+	if (!priv->rx_ring[q])
+		goto error;
+
+	priv->dirty_rx[q] = 0;
+
+	/* Allocate all TX descriptors. */
+	ring_size = sizeof(struct ravb_tx_desc) * (priv->num_tx_ring[q] + 1);
+	priv->tx_ring[q] = dma_alloc_coherent(NULL, ring_size,
+					      &priv->tx_desc_dma[q],
+					      GFP_KERNEL);
+	if (!priv->tx_ring[q])
+		goto error;
+
+	return 0;
+
+error:
+	ravb_ring_free(ndev, q);
+
+	return -ENOMEM;
+}
+
+/* E-MAC init function */
+static void ravb_emac_init(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	u32 ecmr;
+
+	/* Receive frame limit set register */
+	ravb_write(ndev, ndev->mtu + ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN, RFLR);
+
+	/* PAUSE prohibition */
+	ecmr =  ravb_read(ndev, ECMR);
+	ecmr &= ECMR_DM;
+	ecmr |= ECMR_ZPF | (priv->duplex ? ECMR_DM : 0) | ECMR_TE | ECMR_RE;
+	ravb_write(ndev, ecmr, ECMR);
+
+	ravb_set_rate(ndev);
+
+	/* Set MAC address */
+	ravb_write(ndev,
+		   (ndev->dev_addr[0] << 24) | (ndev->dev_addr[1] << 16) |
+		   (ndev->dev_addr[2] << 8)  | (ndev->dev_addr[3]), MAHR);
+	ravb_write(ndev,
+		   (ndev->dev_addr[4] << 8)  | (ndev->dev_addr[5]), MALR);
+
+	ravb_write(ndev, 1, MPR);
+
+	/* E-MAC status register clear */
+	ravb_write(ndev, ECSR_ICD | ECSR_MPD, ECSR);
+
+	/* E-MAC interrupt enable register */
+	ravb_write(ndev, ECSIPR_ICDIP | ECSIPR_MPDIP | ECSIPR_LCHNGIP, ECSIPR);
+}
+
+/* Device init function for Ethernet AVB */
+static int ravb_dmac_init(struct net_device *ndev)
+{
+	int error;
+
+	/* Set CONFIG mode */
+	error = ravb_config(ndev);
+	if (error)
+		return error;
+
+	error = ravb_ring_init(ndev, RAVB_BE);
+	if (error)
+		return error;
+	error = ravb_ring_init(ndev, RAVB_NC);
+	if (error) {
+		ravb_ring_free(ndev, RAVB_BE);
+		return error;
+	}
+
+	/* Descriptor format */
+	ravb_ring_format(ndev, RAVB_BE);
+	ravb_ring_format(ndev, RAVB_NC);
+
+#if defined(__LITTLE_ENDIAN)
+	ravb_write(ndev, ravb_read(ndev, CCC) & ~CCC_BOC, CCC);
+#else
+	ravb_write(ndev, ravb_read(ndev, CCC) | CCC_BOC, CCC);
+#endif
+
+	/* Set AVB RX */
+	ravb_write(ndev, RCR_EFFS | RCR_ENCF | RCR_ETS0 | 0x18000000, RCR);
+
+	/* Set FIFO size */
+	ravb_write(ndev, TGC_TQP_AVBMODE1 | 0x00222200, TGC);
+
+	/* Timestamp enable */
+	ravb_write(ndev, TCCR_TFEN, TCCR);
+
+	/* Interrupt enable: */
+	/* Frame receive */
+	ravb_write(ndev, RIC0_FRE0 | RIC0_FRE1, RIC0);
+	/* Receive FIFO full warning */
+	ravb_write(ndev, RIC1_RFWE, RIC1);
+	/* Receive FIFO full error, descriptor empty */
+	ravb_write(ndev, RIC2_QFE0 | RIC2_QFE1 | RIC2_RFFE, RIC2);
+	/* Frame transmitted, timestamp FIFO updated */
+	ravb_write(ndev, TIC_FTE0 | TIC_FTE1 | TIC_TFUE, TIC);
+
+	/* Setting the control will start the AVB-DMAC process. */
+	ravb_write(ndev, (ravb_read(ndev, CCC) & ~CCC_OPC) | CCC_OPC_OPERATION,
+		   CCC);
+
+	return 0;
+}
+
+/* Free TX skb function for AVB-IP */
+static int ravb_tx_free(struct net_device *ndev, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &priv->stats[q];
+	struct ravb_tx_desc *desc;
+	int free_num = 0;
+	int entry = 0;
+	u32 size;
+
+	for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {
+		entry = priv->dirty_tx[q] % priv->num_tx_ring[q];
+		desc = &priv->tx_ring[q][entry];
+		if (desc->die_dt != DT_FEMPTY)
+			break;
+		/* Descriptor type must be checked before all other reads */
+		dma_rmb();
+		size = le16_to_cpu(desc->ds_tagl) & TX_DS;
+		/* Free the original skb. */
+		if (priv->tx_skb[q][entry]) {
+			dma_unmap_single(&ndev->dev, le32_to_cpu(desc->dptr),
+					 size, DMA_TO_DEVICE);
+			dev_kfree_skb_any(priv->tx_skb[q][entry]);
+			priv->tx_skb[q][entry] = NULL;
+			free_num++;
+		}
+		stats->tx_packets++;
+		stats->tx_bytes += size;
+		desc->die_dt = DT_EEMPTY;
+	}
+	return free_num;
+}
+
+static void ravb_get_tx_tstamp(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct ravb_tstamp_skb *ts_skb, *ts_skb2;
+	struct skb_shared_hwtstamps shhwtstamps;
+	struct sk_buff *skb;
+	struct timespec64 ts;
+	u16 tag, tfa_tag;
+	int count;
+	u32 tfa2;
+
+	count = (ravb_read(ndev, TSR) & TSR_TFFL) >> 8;
+	while (count--) {
+		tfa2 = ravb_read(ndev, TFA2);
+		tfa_tag = (tfa2 & TFA2_TST) >> 16;
+		ts.tv_nsec = (u64)ravb_read(ndev, TFA0);
+		ts.tv_sec = ((u64)(tfa2 & TFA2_TSV) << 32) |
+			    ravb_read(ndev, TFA1);
+		memset(&shhwtstamps, 0, sizeof(shhwtstamps));
+		shhwtstamps.hwtstamp = timespec64_to_ktime(ts);
+		list_for_each_entry_safe(ts_skb, ts_skb2, &priv->ts_skb_list,
+					 list) {
+			skb = ts_skb->skb;
+			tag = ts_skb->tag;
+			list_del(&ts_skb->list);
+			kfree(ts_skb);
+			if (tag == tfa_tag) {
+				skb_tstamp_tx(skb, &shhwtstamps);
+				break;
+			}
+		}
+		ravb_write(ndev, ravb_read(ndev, TCCR) | TCCR_TFR, TCCR);
+	}
+}
+
+/* Packet receive function for Ethernet AVB */
+static bool ravb_rx(struct net_device *ndev, int *quota, int q)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int entry = priv->cur_rx[q] % priv->num_rx_ring[q];
+	int boguscnt = (priv->dirty_rx[q] + priv->num_rx_ring[q]) -
+			priv->cur_rx[q];
+	struct net_device_stats *stats = &priv->stats[q];
+	struct ravb_ex_rx_desc *desc;
+	struct sk_buff *skb;
+	dma_addr_t dma_addr;
+	struct timespec64 ts;
+	u16 pkt_len = 0;
+	u8  desc_status;
+	int limit;
+
+	boguscnt = min(boguscnt, *quota);
+	limit = boguscnt;
+	desc = &priv->rx_ring[q][entry];
+	while (desc->die_dt != DT_FEMPTY) {
+		/* Descriptor type must be checked before all other reads */
+		dma_rmb();
+		desc_status = desc->msc;
+		pkt_len = le16_to_cpu(desc->ds_cc) & RX_DS;
+
+		if (--boguscnt < 0)
+			break;
+
+		if (desc_status & MSC_MC)
+			stats->multicast++;
+
+		if (desc_status & (MSC_CRC | MSC_RFE | MSC_RTSF | MSC_RTLF |
+				   MSC_CEEF)) {
+			stats->rx_errors++;
+			if (desc_status & MSC_CRC)
+				stats->rx_crc_errors++;
+			if (desc_status & MSC_RFE)
+				stats->rx_frame_errors++;
+			if (desc_status & (MSC_RTLF | MSC_RTSF))
+				stats->rx_length_errors++;
+			if (desc_status & MSC_CEEF)
+				stats->rx_missed_errors++;
+		} else {
+			u32 get_ts = priv->tstamp_rx_ctrl & RAVB_RXTSTAMP_TYPE;
+
+			skb = priv->rx_skb[q][entry];
+			priv->rx_skb[q][entry] = NULL;
+			dma_sync_single_for_cpu(&ndev->dev,
+						le32_to_cpu(desc->dptr),
+						ALIGN(PKT_BUF_SZ, 16),
+						DMA_FROM_DEVICE);
+			get_ts &= (q == RAVB_NC) ?
+					RAVB_RXTSTAMP_TYPE_V2_L2_EVENT :
+					~RAVB_RXTSTAMP_TYPE_V2_L2_EVENT;
+			if (get_ts) {
+				struct skb_shared_hwtstamps *shhwtstamps;
+
+				shhwtstamps = skb_hwtstamps(skb);
+				memset(shhwtstamps, 0, sizeof(*shhwtstamps));
+				ts.tv_sec = ((u64) le16_to_cpu(desc->ts_sh) <<
+					     32) | le32_to_cpu(desc->ts_sl);
+				ts.tv_nsec = le32_to_cpu(desc->ts_n);
+				shhwtstamps->hwtstamp = timespec64_to_ktime(ts);
+			}
+			skb_put(skb, pkt_len);
+			skb->protocol = eth_type_trans(skb, ndev);
+			napi_gro_receive(&priv->napi[q], skb);
+			stats->rx_packets++;
+			stats->rx_bytes += pkt_len;
+		}
+
+		entry = (++priv->cur_rx[q]) % priv->num_rx_ring[q];
+		desc = &priv->rx_ring[q][entry];
+	}
+
+	/* Refill the RX ring buffers. */
+	for (; priv->cur_rx[q] - priv->dirty_rx[q] > 0; priv->dirty_rx[q]++) {
+		entry = priv->dirty_rx[q] % priv->num_rx_ring[q];
+		desc = &priv->rx_ring[q][entry];
+		/* The size of the buffer should be on 16-byte boundary. */
+		desc->ds_cc = cpu_to_le16(ALIGN(PKT_BUF_SZ, 16));
+
+		if (!priv->rx_skb[q][entry]) {
+			skb = netdev_alloc_skb(ndev,
+					       PKT_BUF_SZ + RAVB_ALIGN - 1);
+			if (!skb)
+				break;	/* Better luck next round. */
+			ravb_set_buffer_align(skb);
+			dma_unmap_single(&ndev->dev, le32_to_cpu(desc->dptr),
+					 ALIGN(PKT_BUF_SZ, 16),
+					 DMA_FROM_DEVICE);
+			dma_addr = dma_map_single(&ndev->dev, skb->data,
+						  le16_to_cpu(desc->ds_cc),
+						  DMA_FROM_DEVICE);
+			skb_checksum_none_assert(skb);
+			if (dma_mapping_error(&ndev->dev, dma_addr)) {
+				dev_kfree_skb_any(skb);
+				break;
+			}
+			desc->dptr = cpu_to_le32(dma_addr);
+			priv->rx_skb[q][entry] = skb;
+		}
+		/* Descriptor type must be set after all the above writes */
+		dma_wmb();
+		desc->die_dt = DT_FEMPTY;
+	}
+
+	*quota -= limit - (++boguscnt);
+
+	return boguscnt <= 0;
+}
+
+static void ravb_rcv_snd_disable(struct net_device *ndev)
+{
+	/* Disable TX and RX */
+	ravb_write(ndev, ravb_read(ndev, ECMR) & ~(ECMR_RE | ECMR_TE), ECMR);
+}
+
+static void ravb_rcv_snd_enable(struct net_device *ndev)
+{
+	/* Enable TX and RX */
+	ravb_write(ndev, ravb_read(ndev, ECMR) | ECMR_RE | ECMR_TE, ECMR);
+}
+
+/* function for waiting dma process finished */
+static int ravb_stop_dma(struct net_device *ndev)
+{
+	int error;
+
+	/* Wait for stopping the hardware TX process */
+	error = ravb_wait(ndev, TCCR,
+			  TCCR_TSRQ0 | TCCR_TSRQ1 | TCCR_TSRQ2 | TCCR_TSRQ3, 0);
+	if (error)
+		return error;
+
+	error = ravb_wait(ndev, CSR, CSR_TPO0 | CSR_TPO1 | CSR_TPO2 | CSR_TPO3,
+			  0);
+	if (error)
+		return error;
+
+	/* Stop the E-MAC's RX/TX processes. */
+	ravb_rcv_snd_disable(ndev);
+
+	/* Wait for stopping the RX DMA process */
+	error = ravb_wait(ndev, CSR, CSR_RPO, 0);
+	if (error)
+		return error;
+
+	/* Stop AVB-DMAC process */
+	return ravb_config(ndev);
+}
+
+/* E-MAC interrupt handler */
+static void ravb_emac_interrupt(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	u32 ecsr, psr;
+
+	ecsr = ravb_read(ndev, ECSR);
+	ravb_write(ndev, ecsr, ECSR);	/* clear interrupt */
+	if (ecsr & ECSR_ICD)
+		ndev->stats.tx_carrier_errors++;
+	if (ecsr & ECSR_LCHNG) {
+		/* Link changed */
+		if (priv->no_avb_link)
+			return;
+		psr = ravb_read(ndev, PSR);
+		if (priv->avb_link_active_low)
+			psr ^= PSR_LMON;
+		if (!(psr & PSR_LMON)) {
+			/* DIsable RX and TX */
+			ravb_rcv_snd_disable(ndev);
+		} else {
+			/* Enable RX and TX */
+			ravb_rcv_snd_enable(ndev);
+		}
+	}
+}
+
+/* Error interrupt handler */
+static void ravb_error_interrupt(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	u32 eis, ris2;
+
+	eis = ravb_read(ndev, EIS);
+	ravb_write(ndev, ~EIS_QFS, EIS);
+	if (eis & EIS_QFS) {
+		ris2 = ravb_read(ndev, RIS2);
+		ravb_write(ndev, ~(RIS2_QFF0 | RIS2_RFFF), RIS2);
+
+		/* Receive Descriptor Empty int */
+		if (ris2 & RIS2_QFF0)
+			priv->stats[RAVB_BE].rx_over_errors++;
+
+		    /* Receive Descriptor Empty int */
+		if (ris2 & RIS2_QFF1)
+			priv->stats[RAVB_NC].rx_over_errors++;
+
+		/* Receive FIFO Overflow int */
+		if (ris2 & RIS2_RFFF)
+			priv->rx_fifo_errors++;
+	}
+}
+
+static irqreturn_t ravb_interrupt(int irq, void *dev_id)
+{
+	struct net_device *ndev = dev_id;
+	struct ravb_private *priv = netdev_priv(ndev);
+	irqreturn_t result = IRQ_NONE;
+	u32 iss;
+
+	spin_lock(&priv->lock);
+	/* Get interrupt status */
+	iss = ravb_read(ndev, ISS);
+
+	/* Received and transmitted interrupts */
+	if (iss & (ISS_FRS | ISS_FTS | ISS_TFUS)) {
+		u32 ris0 = ravb_read(ndev, RIS0);
+		u32 ric0 = ravb_read(ndev, RIC0);
+		u32 tis  = ravb_read(ndev, TIS);
+		u32 tic  = ravb_read(ndev, TIC);
+		int q;
+
+		/* Timestamp updated */
+		if (tis & TIS_TFUF) {
+			ravb_write(ndev, ~TIS_TFUF, TIS);
+			ravb_get_tx_tstamp(ndev);
+			result = IRQ_HANDLED;
+		}
+
+		/* Network control and best effort queue RX/TX */
+		for (q = RAVB_NC; q >= RAVB_BE; q--) {
+			if (((ris0 & ric0) & BIT(q)) ||
+			    ((tis  & tic)  & BIT(q))) {
+				if (napi_schedule_prep(&priv->napi[q])) {
+					/* Mask RX and TX interrupts */
+					ravb_write(ndev, ric0 & ~BIT(q), RIC0);
+					ravb_write(ndev, tic  & ~BIT(q), TIC);
+					__napi_schedule(&priv->napi[q]);
+				} else {
+					netdev_warn(ndev,
+						    "ignoring interrupt, rx status 0x%08x, rx mask 0x%08x,\n",
+						    ris0, ric0);
+					netdev_warn(ndev,
+						    "                    tx status 0x%08x, tx mask 0x%08x.\n",
+						    tis, tic);
+				}
+				result = IRQ_HANDLED;
+			}
+		}
+	}
+
+	/* E-MAC status summary */
+	if (iss & ISS_MS) {
+		ravb_emac_interrupt(ndev);
+		result = IRQ_HANDLED;
+	}
+
+	/* Error status summary */
+	if (iss & ISS_ES) {
+		ravb_error_interrupt(ndev);
+		result = IRQ_HANDLED;
+	}
+
+	if (iss & ISS_CGIS)
+		result = ravb_ptp_interrupt(ndev);
+
+	mmiowb();
+	spin_unlock(&priv->lock);
+	return result;
+}
+
+static int ravb_poll(struct napi_struct *napi, int budget)
+{
+	struct net_device *ndev = napi->dev;
+	struct ravb_private *priv = netdev_priv(ndev);
+	unsigned long flags;
+	int q = napi - priv->napi;
+	int mask = BIT(q);
+	int quota = budget;
+	u32 ris0, tis;
+
+	for (;;) {
+		tis = ravb_read(ndev, TIS);
+		ris0 = ravb_read(ndev, RIS0);
+		if (!((ris0 & mask) || (tis & mask)))
+			break;
+
+		/* Processing RX Descriptor Ring */
+		if (ris0 & mask) {
+			/* Clear RX interrupt */
+			ravb_write(ndev, ~mask, RIS0);
+			if (ravb_rx(ndev, &quota, q))
+				goto out;
+		}
+		/* Processing TX Descriptor Ring */
+		if (tis & mask) {
+			spin_lock_irqsave(&priv->lock, flags);
+			/* Clear TX interrupt */
+			ravb_write(ndev, ~mask, TIS);
+			ravb_tx_free(ndev, q);
+			netif_wake_subqueue(ndev, q);
+			mmiowb();
+			spin_unlock_irqrestore(&priv->lock, flags);
+		}
+	}
+
+	napi_complete(napi);
+
+	/* Re-enable RX/TX interrupts */
+	spin_lock_irqsave(&priv->lock, flags);
+	ravb_write(ndev, ravb_read(ndev, RIC0) | mask, RIC0);
+	ravb_write(ndev, ravb_read(ndev, TIC)  | mask,  TIC);
+	mmiowb();
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	/* Receive error message handling */
+	priv->rx_over_errors =  priv->stats[RAVB_BE].rx_over_errors;
+	priv->rx_over_errors += priv->stats[RAVB_NC].rx_over_errors;
+	if (priv->rx_over_errors != ndev->stats.rx_over_errors) {
+		ndev->stats.rx_over_errors = priv->rx_over_errors;
+		netif_err(priv, rx_err, ndev, "Receive Descriptor Empty\n");
+	}
+	if (priv->rx_fifo_errors != ndev->stats.rx_fifo_errors) {
+		ndev->stats.rx_fifo_errors = priv->rx_fifo_errors;
+		netif_err(priv, rx_err, ndev, "Receive FIFO Overflow\n");
+	}
+out:
+	return budget - quota;
+}
+
+/* PHY state control function */
+static void ravb_adjust_link(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct phy_device *phydev = priv->phydev;
+	bool new_state = false;
+
+	if (phydev->link) {
+		if (phydev->duplex != priv->duplex) {
+			new_state = true;
+			priv->duplex = phydev->duplex;
+			ravb_set_duplex(ndev);
+		}
+
+		if (phydev->speed != priv->speed) {
+			new_state = true;
+			priv->speed = phydev->speed;
+			ravb_set_rate(ndev);
+		}
+		if (!priv->link) {
+			ravb_write(ndev, ravb_read(ndev, ECMR) & ~ECMR_TXF,
+				   ECMR);
+			new_state = true;
+			priv->link = phydev->link;
+			if (priv->no_avb_link)
+				ravb_rcv_snd_enable(ndev);
+		}
+	} else if (priv->link) {
+		new_state = true;
+		priv->link = 0;
+		priv->speed = 0;
+		priv->duplex = -1;
+		if (priv->no_avb_link)
+			ravb_rcv_snd_disable(ndev);
+	}
+
+	if (new_state && netif_msg_link(priv))
+		phy_print_status(phydev);
+}
+
+/* PHY init function */
+static int ravb_phy_init(struct net_device *ndev)
+{
+	struct device_node *np = ndev->dev.parent->of_node;
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct phy_device *phydev;
+	struct device_node *pn;
+
+	priv->link = 0;
+	priv->speed = 0;
+	priv->duplex = -1;
+
+	/* Try connecting to PHY */
+	pn = of_parse_phandle(np, "phy-handle", 0);
+	phydev = of_phy_connect(ndev, pn, ravb_adjust_link, 0,
+				priv->phy_interface);
+	if (!phydev) {
+		netdev_err(ndev, "failed to connect PHY\n");
+		return -ENOENT;
+	}
+
+	netdev_info(ndev, "attached PHY %d (IRQ %d) to driver %s\n",
+		    phydev->addr, phydev->irq, phydev->drv->name);
+
+	priv->phydev = phydev;
+
+	return 0;
+}
+
+/* PHY control start function */
+static int ravb_phy_start(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int error;
+
+	error = ravb_phy_init(ndev);
+	if (error)
+		return error;
+
+	phy_start(priv->phydev);
+
+	return 0;
+}
+
+static int ravb_get_settings(struct net_device *ndev, struct ethtool_cmd *ecmd)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int error = -ENODEV;
+	unsigned long flags;
+
+	if (priv->phydev) {
+		spin_lock_irqsave(&priv->lock, flags);
+		error = phy_ethtool_gset(priv->phydev, ecmd);
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	return error;
+}
+
+static int ravb_set_settings(struct net_device *ndev, struct ethtool_cmd *ecmd)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	unsigned long flags;
+	int error;
+
+	if (!priv->phydev)
+		return -ENODEV;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	/* Disable TX and RX */
+	ravb_rcv_snd_disable(ndev);
+
+	error = phy_ethtool_sset(priv->phydev, ecmd);
+	if (error)
+		goto error_exit;
+
+	if (ecmd->duplex == DUPLEX_FULL)
+		priv->duplex = 1;
+	else
+		priv->duplex = 0;
+
+	ravb_set_duplex(ndev);
+
+error_exit:
+	mdelay(1);
+
+	/* Enable TX and RX */
+	ravb_rcv_snd_enable(ndev);
+
+	mmiowb();
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return error;
+}
+
+static int ravb_nway_reset(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int error = -ENODEV;
+	unsigned long flags;
+
+	if (priv->phydev) {
+		spin_lock_irqsave(&priv->lock, flags);
+		error = phy_start_aneg(priv->phydev);
+		spin_unlock_irqrestore(&priv->lock, flags);
+	}
+
+	return error;
+}
+
+static u32 ravb_get_msglevel(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	return priv->msg_enable;
+}
+
+static void ravb_set_msglevel(struct net_device *ndev, u32 value)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	priv->msg_enable = value;
+}
+
+static const char ravb_gstrings_stats[][ETH_GSTRING_LEN] = {
+	"rx_queue_0_current",
+	"tx_queue_0_current",
+	"rx_queue_0_dirty",
+	"tx_queue_0_dirty",
+	"rx_queue_0_packets",
+	"tx_queue_0_packets",
+	"rx_queue_0_bytes",
+	"tx_queue_0_bytes",
+	"rx_queue_0_mcast_packets",
+	"rx_queue_0_errors",
+	"rx_queue_0_crc_errors",
+	"rx_queue_0_frame_errors",
+	"rx_queue_0_length_errors",
+	"rx_queue_0_missed_errors",
+	"rx_queue_0_over_errors",
+
+	"rx_queue_1_current",
+	"tx_queue_1_current",
+	"rx_queue_1_dirty",
+	"tx_queue_1_dirty",
+	"rx_queue_1_packets",
+	"tx_queue_1_packets",
+	"rx_queue_1_bytes",
+	"tx_queue_1_bytes",
+	"rx_queue_1_mcast_packets",
+	"rx_queue_1_errors",
+	"rx_queue_1_crc_errors",
+	"rx_queue_1_frame_errors_",
+	"rx_queue_1_length_errors",
+	"rx_queue_1_missed_errors",
+	"rx_queue_1_over_errors",
+};
+
+#define RAVB_STATS_LEN	ARRAY_SIZE(ravb_gstrings_stats)
+
+static int ravb_get_sset_count(struct net_device *netdev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return RAVB_STATS_LEN;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static void ravb_get_ethtool_stats(struct net_device *ndev,
+				   struct ethtool_stats *stats, u64 *data)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int i = 0;
+	int q;
+
+	/* Device-specific stats */
+	for (q = RAVB_BE; q < NUM_RX_QUEUE; q++) {
+		struct net_device_stats *stats = &priv->stats[q];
+
+		data[i++] = priv->cur_rx[q];
+		data[i++] = priv->cur_tx[q];
+		data[i++] = priv->dirty_rx[q];
+		data[i++] = priv->dirty_tx[q];
+		data[i++] = stats->rx_packets;
+		data[i++] = stats->tx_packets;
+		data[i++] = stats->rx_bytes;
+		data[i++] = stats->tx_bytes;
+		data[i++] = stats->multicast;
+		data[i++] = stats->rx_errors;
+		data[i++] = stats->rx_crc_errors;
+		data[i++] = stats->rx_frame_errors;
+		data[i++] = stats->rx_length_errors;
+		data[i++] = stats->rx_missed_errors;
+		data[i++] = stats->rx_over_errors;
+	}
+}
+
+static void ravb_get_strings(struct net_device *ndev, u32 stringset, u8 *data)
+{
+	switch (stringset) {
+	case ETH_SS_STATS:
+		memcpy(data, *ravb_gstrings_stats, sizeof(ravb_gstrings_stats));
+		break;
+	}
+}
+
+static void ravb_get_ringparam(struct net_device *ndev,
+			       struct ethtool_ringparam *ring)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	ring->rx_max_pending = BE_RX_RING_MAX;
+	ring->tx_max_pending = BE_TX_RING_MAX;
+	ring->rx_pending = priv->num_rx_ring[RAVB_BE];
+	ring->tx_pending = priv->num_tx_ring[RAVB_BE];
+}
+
+static int ravb_set_ringparam(struct net_device *ndev,
+			      struct ethtool_ringparam *ring)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int error;
+
+	if (ring->tx_pending > BE_TX_RING_MAX ||
+	    ring->rx_pending > BE_RX_RING_MAX ||
+	    ring->tx_pending < BE_TX_RING_MIN ||
+	    ring->rx_pending < BE_RX_RING_MIN)
+		return -EINVAL;
+	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
+		return -EINVAL;
+
+	if (netif_running(ndev)) {
+		netif_device_detach(ndev);
+		/* Stop PTP Clock driver */
+		ravb_ptp_stop(ndev);
+		/* Wait for DMA stopping */
+		error = ravb_stop_dma(ndev);
+		if (error) {
+			netdev_err(ndev,
+				   "cannot set ringparam! Any AVB processes are still running?\n");
+			return error;
+		}
+		synchronize_irq(ndev->irq);
+
+		/* Free all the skb's in the RX queue and the DMA buffers. */
+		ravb_ring_free(ndev, RAVB_BE);
+		ravb_ring_free(ndev, RAVB_NC);
+	}
+
+	/* Set new parameters */
+	priv->num_rx_ring[RAVB_BE] = ring->rx_pending;
+	priv->num_tx_ring[RAVB_BE] = ring->tx_pending;
+
+	if (netif_running(ndev)) {
+		error = ravb_dmac_init(ndev);
+		if (error) {
+			netdev_err(ndev,
+				   "%s: ravb_dmac_init() failed, error %d\n",
+				   __func__, error);
+			return error;
+		}
+
+		ravb_emac_init(ndev);
+
+		/* Initialise PTP Clock driver */
+		ravb_ptp_init(ndev, priv->pdev);
+
+		netif_device_attach(ndev);
+	}
+
+	return 0;
+}
+
+static int ravb_get_ts_info(struct net_device *ndev,
+			    struct ethtool_ts_info *info)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	info->so_timestamping =
+		SOF_TIMESTAMPING_TX_SOFTWARE |
+		SOF_TIMESTAMPING_RX_SOFTWARE |
+		SOF_TIMESTAMPING_SOFTWARE |
+		SOF_TIMESTAMPING_TX_HARDWARE |
+		SOF_TIMESTAMPING_RX_HARDWARE |
+		SOF_TIMESTAMPING_RAW_HARDWARE;
+	info->tx_types = (1 << HWTSTAMP_TX_OFF) | (1 << HWTSTAMP_TX_ON);
+	info->rx_filters =
+		(1 << HWTSTAMP_FILTER_NONE) |
+		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
+		(1 << HWTSTAMP_FILTER_ALL);
+	info->phc_index = ptp_clock_index(priv->ptp.clock);
+
+	return 0;
+}
+
+static const struct ethtool_ops ravb_ethtool_ops = {
+	.get_settings		= ravb_get_settings,
+	.set_settings		= ravb_set_settings,
+	.nway_reset		= ravb_nway_reset,
+	.get_msglevel		= ravb_get_msglevel,
+	.set_msglevel		= ravb_set_msglevel,
+	.get_link		= ethtool_op_get_link,
+	.get_strings		= ravb_get_strings,
+	.get_ethtool_stats	= ravb_get_ethtool_stats,
+	.get_sset_count		= ravb_get_sset_count,
+	.get_ringparam		= ravb_get_ringparam,
+	.set_ringparam		= ravb_set_ringparam,
+	.get_ts_info		= ravb_get_ts_info,
+};
+
+/* Network device open function for Ethernet AVB */
+static int ravb_open(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	int error;
+
+	napi_enable(&priv->napi[RAVB_BE]);
+	napi_enable(&priv->napi[RAVB_NC]);
+
+	error = request_irq(ndev->irq, ravb_interrupt, IRQF_SHARED, ndev->name,
+			    ndev);
+	if (error) {
+		netdev_err(ndev, "cannot request IRQ\n");
+		goto out_napi_off;
+	}
+
+	/* Device init */
+	error = ravb_dmac_init(ndev);
+	if (error)
+		goto out_free_irq;
+	ravb_emac_init(ndev);
+
+	/* Initialise PTP Clock driver */
+	ravb_ptp_init(ndev, priv->pdev);
+
+	netif_tx_start_all_queues(ndev);
+
+	/* PHY control start */
+	error = ravb_phy_start(ndev);
+	if (error)
+		goto out_ptp_stop;
+
+	return 0;
+
+out_ptp_stop:
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
+out_free_irq:
+	free_irq(ndev->irq, ndev);
+out_napi_off:
+	napi_disable(&priv->napi[RAVB_NC]);
+	napi_disable(&priv->napi[RAVB_BE]);
+	return error;
+}
+
+/* Timeout function for Ethernet AVB */
+static void ravb_tx_timeout(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	netif_err(priv, tx_err, ndev,
+		  "transmit timed out, status %08x, resetting...\n",
+		  ravb_read(ndev, ISS));
+
+	/* tx_errors count up */
+	ndev->stats.tx_errors++;
+
+	schedule_work(&priv->work);
+}
+
+static void ravb_tx_timeout_work(struct work_struct *work)
+{
+	struct ravb_private *priv = container_of(work, struct ravb_private,
+						 work);
+	struct net_device *ndev = priv->ndev;
+
+	netif_tx_stop_all_queues(ndev);
+
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
+
+	/* Wait for DMA stopping */
+	ravb_stop_dma(ndev);
+
+	ravb_ring_free(ndev, RAVB_BE);
+	ravb_ring_free(ndev, RAVB_NC);
+
+	/* Device init */
+	ravb_dmac_init(ndev);
+	ravb_emac_init(ndev);
+
+	/* Initialise PTP Clock driver */
+	ravb_ptp_init(ndev, priv->pdev);
+
+	netif_tx_start_all_queues(ndev);
+}
+
+/* Packet transmit function for Ethernet AVB */
+static netdev_tx_t ravb_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct ravb_tstamp_skb *ts_skb = NULL;
+	u16 q = skb_get_queue_mapping(skb);
+	struct ravb_tx_desc *desc;
+	unsigned long flags;
+	u32 dma_addr;
+	void *buffer;
+	u32 entry;
+	u32 tccr;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->cur_tx[q] - priv->dirty_tx[q] >= priv->num_tx_ring[q]) {
+		netif_err(priv, tx_queued, ndev,
+			  "still transmitting with the full ring!\n");
+		netif_stop_subqueue(ndev, q);
+		spin_unlock_irqrestore(&priv->lock, flags);
+		return NETDEV_TX_BUSY;
+	}
+	entry = priv->cur_tx[q] % priv->num_tx_ring[q];
+	priv->tx_skb[q][entry] = skb;
+
+	if (skb_put_padto(skb, ETH_ZLEN))
+		goto drop;
+
+	buffer = PTR_ALIGN(priv->tx_buffers[q][entry], RAVB_ALIGN);
+	memcpy(buffer, skb->data, skb->len);
+	desc = &priv->tx_ring[q][entry];
+	desc->ds_tagl = cpu_to_le16(skb->len);
+	dma_addr = dma_map_single(&ndev->dev, buffer, skb->len, DMA_TO_DEVICE);
+	if (dma_mapping_error(&ndev->dev, dma_addr))
+		goto drop;
+	desc->dptr = cpu_to_le32(dma_addr);
+
+	/* TX timestamp required */
+	if (q == RAVB_NC) {
+		ts_skb = kmalloc(sizeof(*ts_skb), GFP_ATOMIC);
+		if (!ts_skb) {
+			dma_unmap_single(&ndev->dev, dma_addr, skb->len,
+					 DMA_TO_DEVICE);
+			goto drop;
+		}
+		ts_skb->skb = skb;
+		ts_skb->tag = priv->ts_skb_tag++;
+		priv->ts_skb_tag &= 0x3ff;
+		list_add_tail(&ts_skb->list, &priv->ts_skb_list);
+
+		/* TAG and timestamp required flag */
+		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+		skb_tx_timestamp(skb);
+		desc->tagh_tsr = (ts_skb->tag >> 4) | TX_TSR;
+		desc->ds_tagl |= le16_to_cpu(ts_skb->tag << 12);
+	}
+
+	/* Descriptor type must be set after all the above writes */
+	dma_wmb();
+	desc->die_dt = DT_FSINGLE;
+
+	tccr = ravb_read(ndev, TCCR);
+	if (!(tccr & (TCCR_TSRQ0 << q)))
+		ravb_write(ndev, tccr | (TCCR_TSRQ0 << q), TCCR);
+
+	priv->cur_tx[q]++;
+	if (priv->cur_tx[q] - priv->dirty_tx[q] >= priv->num_tx_ring[q] &&
+	    !ravb_tx_free(ndev, q))
+		netif_stop_subqueue(ndev, q);
+
+exit:
+	mmiowb();
+	spin_unlock_irqrestore(&priv->lock, flags);
+	return NETDEV_TX_OK;
+
+drop:
+	dev_kfree_skb_any(skb);
+	priv->tx_skb[q][entry] = NULL;
+	goto exit;
+}
+
+static u16 ravb_select_queue(struct net_device *ndev, struct sk_buff *skb,
+			     void *accel_priv, select_queue_fallback_t fallback)
+{
+	/* If skb needs TX timestamp, it is handled in network control queue */
+	return (skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) ? RAVB_NC :
+							       RAVB_BE;
+
+}
+
+static struct net_device_stats *ravb_get_stats(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct net_device_stats *nstats, *stats0, *stats1;
+
+	nstats = &ndev->stats;
+	stats0 = &priv->stats[RAVB_BE];
+	stats1 = &priv->stats[RAVB_NC];
+
+	nstats->tx_dropped += ravb_read(ndev, TROCR);
+	ravb_write(ndev, 0, TROCR);	/* (write clear) */
+	nstats->collisions += ravb_read(ndev, CDCR);
+	ravb_write(ndev, 0, CDCR);	/* (write clear) */
+	nstats->tx_carrier_errors += ravb_read(ndev, LCCR);
+	ravb_write(ndev, 0, LCCR);	/* (write clear) */
+
+	nstats->tx_carrier_errors += ravb_read(ndev, CERCR);
+	ravb_write(ndev, 0, CERCR);	/* (write clear) */
+	nstats->tx_carrier_errors += ravb_read(ndev, CEECR);
+	ravb_write(ndev, 0, CEECR);	/* (write clear) */
+
+	nstats->rx_packets = stats0->rx_packets + stats1->rx_packets;
+	nstats->tx_packets = stats0->tx_packets + stats1->tx_packets;
+	nstats->rx_bytes = stats0->rx_bytes + stats1->rx_bytes;
+	nstats->tx_bytes = stats0->tx_bytes + stats1->tx_bytes;
+	nstats->multicast = stats0->multicast + stats1->multicast;
+	nstats->rx_errors = stats0->rx_errors + stats1->rx_errors;
+	nstats->rx_crc_errors = stats0->rx_crc_errors + stats1->rx_crc_errors;
+	nstats->rx_frame_errors =
+		stats0->rx_frame_errors + stats1->rx_frame_errors;
+	nstats->rx_length_errors =
+		stats0->rx_length_errors + stats1->rx_length_errors;
+	nstats->rx_missed_errors =
+		stats0->rx_missed_errors + stats1->rx_missed_errors;
+	nstats->rx_over_errors =
+		stats0->rx_over_errors + stats1->rx_over_errors;
+
+	return nstats;
+}
+
+/* Update promiscuous bit */
+static void ravb_set_rx_mode(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	unsigned long flags;
+	u32 ecmr;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	ecmr = ravb_read(ndev, ECMR);
+	if (ndev->flags & IFF_PROMISC)
+		ecmr |=  ECMR_PRM;
+	else
+		ecmr &= ~ECMR_PRM;
+	ravb_write(ndev, ecmr, ECMR);
+	mmiowb();
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+/* Device close function for Ethernet AVB */
+static int ravb_close(struct net_device *ndev)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct ravb_tstamp_skb *ts_skb, *ts_skb2;
+
+	netif_tx_stop_all_queues(ndev);
+
+	/* Disable interrupts by clearing the interrupt masks. */
+	ravb_write(ndev, 0, RIC0);
+	ravb_write(ndev, 0, RIC1);
+	ravb_write(ndev, 0, RIC2);
+	ravb_write(ndev, 0, TIC);
+
+	/* Stop PTP Clock driver */
+	ravb_ptp_stop(ndev);
+
+	/* Set the config mode to stop the AVB-DMAC's processes */
+	if (ravb_stop_dma(ndev) < 0)
+		netdev_err(ndev,
+			   "device will be stopped after h/w processes are done.\n");
+
+	/* Clear the timestamp list */
+	list_for_each_entry_safe(ts_skb, ts_skb2, &priv->ts_skb_list, list) {
+		list_del(&ts_skb->list);
+		kfree(ts_skb);
+	}
+
+	/* PHY disconnect */
+	if (priv->phydev) {
+		phy_stop(priv->phydev);
+		phy_disconnect(priv->phydev);
+		priv->phydev = NULL;
+	}
+
+	free_irq(ndev->irq, ndev);
+
+	napi_disable(&priv->napi[RAVB_NC]);
+	napi_disable(&priv->napi[RAVB_BE]);
+
+	/* Free all the skb's in the RX queue and the DMA buffers. */
+	ravb_ring_free(ndev, RAVB_BE);
+	ravb_ring_free(ndev, RAVB_NC);
+
+	return 0;
+}
+
+static int ravb_hwtstamp_get(struct net_device *ndev, struct ifreq *req)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct hwtstamp_config config;
+
+	config.flags = 0;
+	config.tx_type = priv->tstamp_tx_ctrl ? HWTSTAMP_TX_ON :
+						HWTSTAMP_TX_OFF;
+	if (priv->tstamp_rx_ctrl & RAVB_RXTSTAMP_TYPE_V2_L2_EVENT)
+		config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
+	else if (priv->tstamp_rx_ctrl & RAVB_RXTSTAMP_TYPE_ALL)
+		config.rx_filter = HWTSTAMP_FILTER_ALL;
+	else
+		config.rx_filter = HWTSTAMP_FILTER_NONE;
+
+	return copy_to_user(req->ifr_data, &config, sizeof(config)) ?
+		-EFAULT : 0;
+}
+
+/* Control hardware time stamping */
+static int ravb_hwtstamp_set(struct net_device *ndev, struct ifreq *req)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct hwtstamp_config config;
+	u32 tstamp_rx_ctrl = RAVB_RXTSTAMP_ENABLED;
+	u32 tstamp_tx_ctrl;
+
+	if (copy_from_user(&config, req->ifr_data, sizeof(config)))
+		return -EFAULT;
+
+	/* Reserved for future extensions */
+	if (config.flags)
+		return -EINVAL;
+
+	switch (config.tx_type) {
+	case HWTSTAMP_TX_OFF:
+		tstamp_tx_ctrl = 0;
+		break;
+	case HWTSTAMP_TX_ON:
+		tstamp_tx_ctrl = RAVB_TXTSTAMP_ENABLED;
+		break;
+	default:
+		return -ERANGE;
+	}
+
+	switch (config.rx_filter) {
+	case HWTSTAMP_FILTER_NONE:
+		tstamp_rx_ctrl = 0;
+		break;
+	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
+		tstamp_rx_ctrl |= RAVB_RXTSTAMP_TYPE_V2_L2_EVENT;
+		break;
+	default:
+		config.rx_filter = HWTSTAMP_FILTER_ALL;
+		tstamp_rx_ctrl |= RAVB_RXTSTAMP_TYPE_ALL;
+	}
+
+	priv->tstamp_tx_ctrl = tstamp_tx_ctrl;
+	priv->tstamp_rx_ctrl = tstamp_rx_ctrl;
+
+	return copy_to_user(req->ifr_data, &config, sizeof(config)) ?
+		-EFAULT : 0;
+}
+
+/* ioctl to device function */
+static int ravb_do_ioctl(struct net_device *ndev, struct ifreq *req, int cmd)
+{
+	struct ravb_private *priv = netdev_priv(ndev);
+	struct phy_device *phydev = priv->phydev;
+
+	if (!netif_running(ndev))
+		return -EINVAL;
+
+	if (!phydev)
+		return -ENODEV;
+
+	switch (cmd) {
+	case SIOCGHWTSTAMP:
+		return ravb_hwtstamp_get(ndev, req);
+	case SIOCSHWTSTAMP:
+		return ravb_hwtstamp_set(ndev, req);
+	}
+
+	return phy_mii_ioctl(phydev, req, cmd);
+}
+
+static const struct net_device_ops ravb_netdev_ops = {
+	.ndo_open		= ravb_open,
+	.ndo_stop		= ravb_close,
+	.ndo_start_xmit		= ravb_start_xmit,
+	.ndo_select_queue	= ravb_select_queue,
+	.ndo_get_stats		= ravb_get_stats,
+	.ndo_set_rx_mode	= ravb_set_rx_mode,
+	.ndo_tx_timeout		= ravb_tx_timeout,
+	.ndo_do_ioctl		= ravb_do_ioctl,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_change_mtu		= eth_change_mtu,
+};
+
+/* MDIO bus init function */
+static int ravb_mdio_init(struct ravb_private *priv)
+{
+	struct platform_device *pdev = priv->pdev;
+	struct device *dev = &pdev->dev;
+	int error;
+
+	/* Bitbang init */
+	priv->mdiobb.ops = &bb_ops;
+
+	/* MII controller setting */
+	priv->mii_bus = alloc_mdio_bitbang(&priv->mdiobb);
+	if (!priv->mii_bus)
+		return -ENOMEM;
+
+	/* Hook up MII support for ethtool */
+	priv->mii_bus->name = "ravb_mii";
+	priv->mii_bus->parent = dev;
+	snprintf(priv->mii_bus->id, MII_BUS_ID_SIZE, "%s-%x",
+		 pdev->name, pdev->id);
+
+	/* Register MDIO bus */
+	error = of_mdiobus_register(priv->mii_bus, dev->of_node);
+	if (error)
+		goto out_free_bus;
+
+	return 0;
+
+out_free_bus:
+	free_mdio_bitbang(priv->mii_bus);
+	return error;
+}
+
+/* MDIO bus release function */
+static int ravb_mdio_release(struct ravb_private *priv)
+{
+	/* Unregister mdio bus */
+	mdiobus_unregister(priv->mii_bus);
+
+	/* Free bitbang info */
+	free_mdio_bitbang(priv->mii_bus);
+
+	return 0;
+}
+
+static int ravb_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct ravb_private *priv;
+	struct net_device *ndev;
+	int error, irq, q;
+	struct resource *res;
+
+	if (!np) {
+		dev_err(&pdev->dev,
+			"this driver is required to be instantiated from device tree\n");
+		return -EINVAL;
+	}
+
+	/* Get base address */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "invalid resource\n");
+		return -EINVAL;
+	}
+
+	ndev = alloc_etherdev_mqs(sizeof(struct ravb_private),
+				  NUM_TX_QUEUE, NUM_RX_QUEUE);
+	if (!ndev)
+		return -ENOMEM;
+
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	/* The Ether-specific entries in the device structure. */
+	ndev->base_addr = res->start;
+	ndev->dma = -1;
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		error = -ENODEV;
+		goto out_release;
+	}
+	ndev->irq = irq;
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	priv = netdev_priv(ndev);
+	priv->ndev = ndev;
+	priv->pdev = pdev;
+	priv->num_tx_ring[RAVB_BE] = BE_TX_RING_SIZE;
+	priv->num_rx_ring[RAVB_BE] = BE_RX_RING_SIZE;
+	priv->num_tx_ring[RAVB_NC] = NC_TX_RING_SIZE;
+	priv->num_rx_ring[RAVB_NC] = NC_RX_RING_SIZE;
+	priv->addr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->addr)) {
+		error = PTR_ERR(priv->addr);
+		goto out_release;
+	}
+
+	spin_lock_init(&priv->lock);
+	INIT_WORK(&priv->work, ravb_tx_timeout_work);
+
+	priv->phy_interface = of_get_phy_mode(np);
+
+	priv->no_avb_link = of_property_read_bool(np, "renesas,no-ether-link");
+	priv->avb_link_active_low =
+		of_property_read_bool(np, "renesas,ether-link-active-low");
+
+	/* Set function */
+	ndev->netdev_ops = &ravb_netdev_ops;
+	ndev->ethtool_ops = &ravb_ethtool_ops;
+
+	/* Set AVB config mode */
+	ravb_write(ndev, (ravb_read(ndev, CCC) & ~CCC_OPC) | CCC_OPC_CONFIG,
+		   CCC);
+
+	/* Set CSEL value */
+	ravb_write(ndev, (ravb_read(ndev, CCC) & ~CCC_CSEL) | CCC_CSEL_HPB,
+		   CCC);
+
+	/* Set GTI value */
+	ravb_write(ndev, ((1000 << 20) / 130) & GTI_TIV, GTI);
+
+	/* Request GTI loading */
+	ravb_write(ndev, ravb_read(ndev, GCCR) | GCCR_LTI, GCCR);
+
+	/* Allocate descriptor base address table */
+	priv->desc_bat_size = sizeof(struct ravb_desc) * DBAT_ENTRY_NUM;
+	priv->desc_bat = dma_alloc_coherent(NULL, priv->desc_bat_size,
+					    &priv->desc_bat_dma, GFP_KERNEL);
+	if (!priv->desc_bat) {
+		dev_err(&ndev->dev,
+			"Cannot allocate desc base address table (size %d bytes)\n",
+			priv->desc_bat_size);
+		error = -ENOMEM;
+		goto out_release;
+	}
+	for (q = RAVB_BE; q < DBAT_ENTRY_NUM; q++)
+		priv->desc_bat[q].die_dt = DT_EOS;
+	ravb_write(ndev, priv->desc_bat_dma, DBAT);
+
+	/* Initialise HW timestamp list */
+	INIT_LIST_HEAD(&priv->ts_skb_list);
+
+	/* Debug message level */
+	priv->msg_enable = RAVB_DEF_MSG_ENABLE;
+
+	/* Read and set MAC address */
+	ravb_read_mac_address(ndev, of_get_mac_address(np));
+	if (!is_valid_ether_addr(ndev->dev_addr)) {
+		dev_warn(&pdev->dev,
+			 "no valid MAC address supplied, using a random one\n");
+		eth_hw_addr_random(ndev);
+	}
+
+	/* MDIO bus init */
+	error = ravb_mdio_init(priv);
+	if (error) {
+		dev_err(&ndev->dev, "failed to initialize MDIO\n");
+		goto out_dma_free;
+	}
+
+	netif_napi_add(ndev, &priv->napi[RAVB_BE], ravb_poll, 64);
+	netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll, 64);
+
+	/* Network device register */
+	error = register_netdev(ndev);
+	if (error)
+		goto out_napi_del;
+
+	/* Print device information */
+	netdev_info(ndev, "Base address at %#x, %pM, IRQ %d.\n",
+		    (u32)ndev->base_addr, ndev->dev_addr, ndev->irq);
+
+	platform_set_drvdata(pdev, ndev);
+
+	return 0;
+
+out_napi_del:
+	netif_napi_del(&priv->napi[RAVB_NC]);
+	netif_napi_del(&priv->napi[RAVB_BE]);
+	ravb_mdio_release(priv);
+out_dma_free:
+	dma_free_coherent(NULL, priv->desc_bat_size, priv->desc_bat,
+			  priv->desc_bat_dma);
+out_release:
+	if (ndev)
+		free_netdev(ndev);
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	return error;
+}
+
+static int ravb_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct ravb_private *priv = netdev_priv(ndev);
+
+	dma_free_coherent(NULL, priv->desc_bat_size, priv->desc_bat,
+			  priv->desc_bat_dma);
+	/* Set reset mode */
+	ravb_write(ndev, CCC_OPC_RESET, CCC);
+	pm_runtime_put_sync(&pdev->dev);
+	unregister_netdev(ndev);
+	netif_napi_del(&priv->napi[RAVB_NC]);
+	netif_napi_del(&priv->napi[RAVB_BE]);
+	ravb_mdio_release(priv);
+	pm_runtime_disable(&pdev->dev);
+	free_netdev(ndev);
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int ravb_runtime_nop(struct device *dev)
+{
+	/* Runtime PM callback shared between ->runtime_suspend()
+	 * and ->runtime_resume(). Simply returns success.
+	 *
+	 * This driver re-initializes all registers after
+	 * pm_runtime_get_sync() anyway so there is no need
+	 * to save and restore registers here.
+	 */
+	return 0;
+}
+
+static const struct dev_pm_ops ravb_dev_pm_ops = {
+	.runtime_suspend = ravb_runtime_nop,
+	.runtime_resume = ravb_runtime_nop,
+};
+
+#define RAVB_PM_OPS (&ravb_dev_pm_ops)
+#else
+#define RAVB_PM_OPS NULL
+#endif
+
+static const struct of_device_id ravb_match_table[] = {
+	{ .compatible = "renesas,etheravb-r8a7790" },
+	{ .compatible = "renesas,etheravb-r8a7794" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ravb_match_table);
+
+static struct platform_driver ravb_driver = {
+	.probe		= ravb_probe,
+	.remove		= ravb_remove,
+	.driver = {
+		.name	= "ravb",
+		.pm	= RAVB_PM_OPS,
+		.of_match_table = ravb_match_table,
+	},
+};
+
+module_platform_driver(ravb_driver);
+
+MODULE_AUTHOR("Mitsuhiro Kimura, Masaru Nagai");
+MODULE_DESCRIPTION("Renesas Ethernet AVB driver");
+MODULE_LICENSE("GPL v2");