diff mbox series

[v8,3/3] net: ax88796c: ASIX AX88796C SPI Ethernet Adapter Driver

Message ID 20201202214709.16192-4-l.stelmach@samsung.com (mailing list archive)
State New, archived
Headers show
Series AX88796C SPI Ethernet Adapter | expand

Commit Message

Łukasz Stelmach Dec. 2, 2020, 9:47 p.m. UTC
ASIX AX88796[1] is a versatile ethernet adapter chip, that can be
connected to a CPU with a 8/16-bit bus or with an SPI. This driver
supports SPI connection.

The driver has been ported from the vendor kernel for ARTIK5[2]
boards. Several changes were made to adapt it to the current kernel
which include:

+ updated DT configuration,
+ clock configuration moved to DT,
+ new timer, ethtool and gpio APIs,
+ dev_* instead of pr_* and custom printk() wrappers,
+ removed awkward vendor power managemtn.
+ introduced ethtool tunable to control SPI compression

[1] https://www.asix.com.tw/products.php?op=pItemdetail&PItemID=104;65;86&PLine=65
[2] https://git.tizen.org/cgit/profile/common/platform/kernel/linux-3.10-artik/

The other ax88796 driver is for NE2000 compatible AX88796L chip. These
chips are not compatible. Hence, two separate drivers are required.

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 MAINTAINERS                                |    6 +
 drivers/net/ethernet/Kconfig               |    1 +
 drivers/net/ethernet/Makefile              |    1 +
 drivers/net/ethernet/asix/Kconfig          |   35 +
 drivers/net/ethernet/asix/Makefile         |    6 +
 drivers/net/ethernet/asix/ax88796c_ioctl.c |  221 ++++
 drivers/net/ethernet/asix/ax88796c_ioctl.h |   26 +
 drivers/net/ethernet/asix/ax88796c_main.c  | 1127 ++++++++++++++++++++
 drivers/net/ethernet/asix/ax88796c_main.h  |  561 ++++++++++
 drivers/net/ethernet/asix/ax88796c_spi.c   |  112 ++
 drivers/net/ethernet/asix/ax88796c_spi.h   |   69 ++
 include/uapi/linux/ethtool.h               |    1 +
 net/ethtool/common.c                       |    1 +
 13 files changed, 2167 insertions(+)
 create mode 100644 drivers/net/ethernet/asix/Kconfig
 create mode 100644 drivers/net/ethernet/asix/Makefile
 create mode 100644 drivers/net/ethernet/asix/ax88796c_ioctl.c
 create mode 100644 drivers/net/ethernet/asix/ax88796c_ioctl.h
 create mode 100644 drivers/net/ethernet/asix/ax88796c_main.c
 create mode 100644 drivers/net/ethernet/asix/ax88796c_main.h
 create mode 100644 drivers/net/ethernet/asix/ax88796c_spi.c
 create mode 100644 drivers/net/ethernet/asix/ax88796c_spi.h

Comments

Jakub Kicinski Dec. 5, 2020, 3:37 a.m. UTC | #1
On Wed,  2 Dec 2020 22:47:09 +0100 Łukasz Stelmach wrote:
> ASIX AX88796[1] is a versatile ethernet adapter chip, that can be
> connected to a CPU with a 8/16-bit bus or with an SPI. This driver
> supports SPI connection.
> 
> The driver has been ported from the vendor kernel for ARTIK5[2]
> boards. Several changes were made to adapt it to the current kernel
> which include:
> 
> + updated DT configuration,
> + clock configuration moved to DT,
> + new timer, ethtool and gpio APIs,
> + dev_* instead of pr_* and custom printk() wrappers,
> + removed awkward vendor power managemtn.
> + introduced ethtool tunable to control SPI compression
> 
> [1] https://www.asix.com.tw/products.php?op=pItemdetail&PItemID=104;65;86&PLine=65
> [2] https://git.tizen.org/cgit/profile/common/platform/kernel/linux-3.10-artik/
> 
> The other ax88796 driver is for NE2000 compatible AX88796L chip. These
> chips are not compatible. Hence, two separate drivers are required.
> 
> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>

> +	case ETHTOOL_SPI_COMPRESSION:
> +		if (netif_running(ndev))
> +			return -EBUSY;
> +		if ((*(u32 *)data) != 1)
> +			return -EINVAL;
> +		ax_local->capabilities &= ~AX_CAP_COMP;
> +		ax_local->capabilities |= (*(u32 *)data) == 1 ? AX_CAP_COMP : 0;

Since you're just using a single bit of information please use 
a private driver flag.

> +	headroom = skb_headroom(skb);
> +	tailroom = skb_tailroom(skb);
> +	padlen = ((pkt_len + 3) & 0x7FC) - pkt_len;

	round_up(pkt_len, 4) - pkt_len;

> +	tol_len = ((pkt_len + 3) & 0x7FC) +
> +			TX_OVERHEAD + TX_EOP_SIZE + spi_len;

Ditto

> +	seq_num = ++ax_local->seq_num & 0x1F;
> +
> +	info = (struct tx_pkt_info *)skb->cb;
> +	info->pkt_len = pkt_len;
> +
> +	if ((!skb_cloned(skb)) &&
> +	    (headroom >= (TX_OVERHEAD + spi_len)) &&
> +	    (tailroom >= (padlen + TX_EOP_SIZE))) {

> +	} else {

I think you can just use pskb_expand_head() instead of all this

> +		tx_skb = alloc_skb(tol_len, GFP_KERNEL);
> +		if (!tx_skb)
> +			return NULL;
> +
> +		/* Write SPI TXQ header */
> +		memcpy(skb_put(tx_skb, spi_len), ax88796c_tx_cmd_buf, spi_len);
> +
> +		info->seq_num = seq_num;
> +		ax88796c_proc_tx_hdr(info, skb->ip_summed);
> +
> +		/* SOP and SEG header */
> +		memcpy(skb_put(tx_skb, TX_OVERHEAD),
> +		       &info->sop, TX_OVERHEAD);
> +
> +		/* Packet */
> +		memcpy(skb_put(tx_skb, ((pkt_len + 3) & 0xFFFC)),
> +		       skb->data, pkt_len);
> +
> +		/* EOP header */
> +		memcpy(skb_put(tx_skb, TX_EOP_SIZE),
> +		       &info->eop, TX_EOP_SIZE);
> +
> +		skb_unlink(skb, q);
> +		dev_kfree_skb(skb);
> +	}

> +static void
> +ax88796c_skb_return(struct ax88796c_device *ax_local, struct sk_buff *skb,
> +		    struct rx_header *rxhdr)
> +{
> +	struct net_device *ndev = ax_local->ndev;
> +	int status;
> +
> +	do {
> +		if (!(ndev->features & NETIF_F_RXCSUM))
> +			break;
> +
> +		/* checksum error bit is set */
> +		if ((rxhdr->flags & RX_HDR3_L3_ERR) ||
> +		    (rxhdr->flags & RX_HDR3_L4_ERR))
> +			break;
> +
> +		/* Other types may be indicated by more than one bit. */
> +		if ((rxhdr->flags & RX_HDR3_L4_TYPE_TCP) ||
> +		    (rxhdr->flags & RX_HDR3_L4_TYPE_UDP))
> +			skb->ip_summed = CHECKSUM_UNNECESSARY;
> +	} while (0);
> +
> +	ax_local->stats.rx_packets++;
> +	ax_local->stats.rx_bytes += skb->len;
> +	skb->dev = ndev;
> +
> +	skb->truesize = skb->len + sizeof(struct sk_buff);

Why do you modify truesize?

> +	skb->protocol = eth_type_trans(skb, ax_local->ndev);
> +
> +	netif_info(ax_local, rx_status, ndev, "< rx, len %zu, type 0x%x\n",
> +		   skb->len + sizeof(struct ethhdr), skb->protocol);
> +
> +	status = netif_rx_ni(skb);
> +	if (status != NET_RX_SUCCESS)
> +		netif_info(ax_local, rx_err, ndev,
> +			   "netif_rx status %d\n", status);
> +}
> +
> +static void
> +ax88796c_rx_fixup(struct ax88796c_device *ax_local, struct sk_buff *rx_skb)
> +{
> +	struct rx_header *rxhdr = (struct rx_header *)rx_skb->data;
> +	struct net_device *ndev = ax_local->ndev;
> +	u16 len;
> +
> +	be16_to_cpus(&rxhdr->flags_len);
> +	be16_to_cpus(&rxhdr->seq_lenbar);
> +	be16_to_cpus(&rxhdr->flags);
> +
> +	if ((((short)rxhdr->flags_len) & RX_HDR1_PKT_LEN) !=
> +			 (~((short)rxhdr->seq_lenbar) & 0x7FF)) {

Why do you cast these values to signed types?
Is the casting necessary at all?

> +		netif_err(ax_local, rx_err, ndev, "Header error\n");
> +
> +		ax_local->stats.rx_frame_errors++;
> +		kfree_skb(rx_skb);
> +		return;
> +	}
> +
> +	if ((rxhdr->flags_len & RX_HDR1_MII_ERR) ||
> +	    (rxhdr->flags_len & RX_HDR1_CRC_ERR)) {
> +		netif_err(ax_local, rx_err, ndev, "CRC or MII error\n");
> +
> +		ax_local->stats.rx_crc_errors++;
> +		kfree_skb(rx_skb);
> +		return;
> +	}
> +
> +	len = rxhdr->flags_len & RX_HDR1_PKT_LEN;
> +	if (netif_msg_pktdata(ax_local)) {
> +		char pfx[IFNAMSIZ + 7];
> +
> +		snprintf(pfx, sizeof(pfx), "%s:     ", ndev->name);
> +		netdev_info(ndev, "RX data, total len %d, packet len %d\n",
> +			    rx_skb->len, len);
> +
> +		netdev_info(ndev, "  Dump RX packet header:");
> +		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
> +			       rx_skb->data, sizeof(*rxhdr), 0);
> +
> +		netdev_info(ndev, "  Dump RX packet:");
> +		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
> +			       rx_skb->data + sizeof(*rxhdr), len, 0);
> +	}
> +
> +	skb_pull(rx_skb, sizeof(*rxhdr));
> +	__pskb_trim(rx_skb, len);

Why __pskb_trim? skb_trim() should do.

> +	return ax88796c_skb_return(ax_local, rx_skb, rxhdr);

please drop the "return", both caller and callee are void.

> +}
> +
> +static int ax88796c_receive(struct net_device *ndev)
> +{
> +	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
> +	struct skb_data *entry;
> +	u16 w_count, pkt_len;
> +	struct sk_buff *skb;
> +	u8 pkt_cnt;
> +
> +	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
> +
> +	/* check rx packet and total word count */
> +	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_RTWCR)
> +		  | RTWCR_RX_LATCH, P0_RTWCR);
> +
> +	pkt_cnt = AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_PKT_MASK;
> +	if (!pkt_cnt)
> +		return 0;
> +
> +	pkt_len = AX_READ(&ax_local->ax_spi, P0_RCPHR) & 0x7FF;
> +
> +	w_count = ((pkt_len + 6 + 3) & 0xFFFC) >> 1;
> +
> +	skb = alloc_skb((w_count * 2), GFP_ATOMIC);

netdev_alloc_skb()

> +	if (!skb) {
> +		AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_DISCARD, P0_RXBCR1);
> +		return 0;
> +	}
> +	entry = (struct skb_data *)skb->cb;
> +
> +	AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_START | w_count, P0_RXBCR1);
> +
> +	axspi_read_rxq(&ax_local->ax_spi,
> +		       skb_put(skb, w_count * 2), skb->len);
> +
> +	/* Check if rx bridge is idle */
> +	if ((AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_RXB_IDLE) == 0) {
> +		netif_err(ax_local, rx_err, ndev,
> +			  "Rx Bridge is not idle\n");
> +		AX_WRITE(&ax_local->ax_spi, RXBCR2_RXB_REINIT, P0_RXBCR2);
> +
> +		entry->state = rx_err;
> +	} else {
> +		entry->state = rx_done;
> +	}
> +
> +	AX_WRITE(&ax_local->ax_spi, ISR_RXPKT, P0_ISR);
> +
> +	ax88796c_rx_fixup(ax_local, skb);
> +
> +	return 1;
> +}

> +static irqreturn_t ax88796c_interrupt(int irq, void *dev_instance)
> +{
> +	struct ax88796c_device *ax_local;
> +	struct net_device *ndev;
> +
> +	ndev = dev_instance;
> +	if (!ndev) {
> +		pr_err("irq %d for unknown device.\n", irq);
> +		return IRQ_RETVAL(0);
> +	}
> +	ax_local = to_ax88796c_device(ndev);
> +
> +	disable_irq_nosync(irq);
> +
> +	netif_dbg(ax_local, intr, ndev, "Interrupt occurred\n");
> +
> +	set_bit(EVENT_INTR, &ax_local->flags);
> +	schedule_work(&ax_local->ax_work);
> +
> +	return IRQ_HANDLED;
> +}

Since you always punt to a workqueue did you consider just using
threaded interrupts instead? 

Also you're not checking if this is actually your devices IRQ that
triggered. You can't set IRQF_SHARED.

> +static int
> +ax88796c_open(struct net_device *ndev)
> +{
> +	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
> +	unsigned long irq_flag = IRQF_SHARED;
> +	int fc = AX_FC_NONE;
> +	int ret;
> +
> +	ret = request_irq(ndev->irq, ax88796c_interrupt,
> +			  irq_flag, ndev->name, ndev);
> +	if (ret) {
> +		netdev_err(ndev, "unable to get IRQ %d (errno=%d).\n",
> +			   ndev->irq, ret);
> +		return ret;
> +	}
> +
> +	mutex_lock(&ax_local->spi_lock);
> +
> +	ret = ax88796c_soft_reset(ax_local);
> +	if (ret < 0) {
> +		mutex_unlock(&ax_local->spi_lock);
> +		return ret;

What frees the IRQ?

> +	}
> +	ax_local->seq_num = 0x1f;
> +
> +	ax88796c_set_mac_addr(ndev);
> +	ax88796c_set_csums(ax_local);
> +
> +	/* Disable stuffing packet */
> +	AX_WRITE(&ax_local->ax_spi,
> +		 AX_READ(&ax_local->ax_spi, P1_RXBSPCR)
> +		 & ~RXBSPCR_STUF_ENABLE, P1_RXBSPCR);

Please use a temporary variable or create a RMW helper.

> +	/* Enable RX packet process */
> +	AX_WRITE(&ax_local->ax_spi, RPPER_RXEN, P1_RPPER);
> +
> +	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_FER)
> +		 | FER_RXEN | FER_TXEN | FER_BSWAP | FER_IRQ_PULL, P0_FER);

Ditto. etc.

> +	ndev = devm_alloc_etherdev(&spi->dev, sizeof(*ax_local));
> +	if (!ndev)
> +		return -ENOMEM;
> +
> +	SET_NETDEV_DEV(ndev, &spi->dev);
> +
> +	ax_local = to_ax88796c_device(ndev);
> +	memset(ax_local, 0, sizeof(*ax_local));

No need to zero out netdev priv, it's zalloced.

> +	mutex_lock(&ax_local->spi_lock);
> +
> +	/* ax88796c gpio reset */
> +	ax88796c_hard_reset(ax_local);
> +
> +	/* Reset AX88796C */
> +	ret = ax88796c_soft_reset(ax_local);
> +	if (ret < 0) {
> +		ret = -ENODEV;
> +		goto err;
> +	}
> +	/* Check board revision */
> +	temp = AX_READ(&ax_local->ax_spi, P2_CRIR);
> +	if ((temp & 0xF) != 0x0) {
> +		dev_err(&spi->dev, "spi read failed: %d\n", temp);
> +		ret = -ENODEV;
> +		goto err;
> +	}

These jump out without releasing the lock.

> +	/* Disable power saving */
> +	AX_WRITE(&ax_local->ax_spi, (AX_READ(&ax_local->ax_spi, P0_PSCR)
> +				     & PSCR_PS_MASK) | PSCR_PS_D0, P0_PSCR);

This is asking for a temporary variable or a RMW helper.

> +	u8			plat_endian;
> +		#define PLAT_LITTLE_ENDIAN	0
> +		#define PLAT_BIG_ENDIAN		1

Why do you store this little nugget of information?

> +/* Tx headers structure */
> +struct tx_sop_header {
> +	/* bit 15-11: flags, bit 10-0: packet length */
> +	u16 flags_len;
> +	/* bit 15-11: sequence number, bit 11-0: packet length bar */
> +	u16 seq_lenbar;
> +} __packed;
> +
> +struct tx_segment_header {
> +	/* bit 15-14: flags, bit 13-11: segment number */
> +	/* bit 10-0: segment length */
> +	u16 flags_seqnum_seglen;
> +	/* bit 15-14: end offset, bit 13-11: start offset */
> +	/* bit 10-0: segment length bar */
> +	u16 eo_so_seglenbar;
> +} __packed;
> +
> +struct tx_eop_header {
> +	/* bit 15-11: sequence number, bit 10-0: packet length */
> +	u16 seq_len;
> +	/* bit 15-11: sequence number bar, bit 10-0: packet length bar */
> +	u16 seqbar_lenbar;
> +} __packed;
> +
> +struct tx_pkt_info {
> +	struct tx_sop_header sop;
> +	struct tx_segment_header seg;
> +	struct tx_eop_header eop;
> +	u16 pkt_len;
> +	u16 seq_num;
> +} __packed;
> +
> +/* Rx headers structure */
> +struct rx_header {
> +	u16 flags_len;
> +	u16 seq_lenbar;
> +	u16 flags;
> +} __packed;

These all look like multiple of 2 bytes. Why do they need to be packed?

> +u16 axspi_read_reg(struct axspi_data *ax_spi, u8 reg)
> +{
> +	int ret;
> +	int len = ax_spi->comp ? 3 : 4;
> +
> +	ax_spi->cmd_buf[0] = 0x03;	/* OP code read register */
> +	ax_spi->cmd_buf[1] = reg;	/* register address */
> +	ax_spi->cmd_buf[2] = 0xFF;	/* dumy cycle */
> +	ax_spi->cmd_buf[3] = 0xFF;	/* dumy cycle */
> +	ret = spi_write_then_read(ax_spi->spi,
> +				  ax_spi->cmd_buf, len,
> +				  ax_spi->rx_buf, 2);
> +	if (ret)
> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
> +	else
> +		le16_to_cpus(ax_spi->rx_buf);
> +
> +	return *(u16 *)ax_spi->rx_buf;

No need to return some specific pattern on failure? Like 0xffff?
Łukasz Stelmach Dec. 16, 2020, 12:42 a.m. UTC | #2
It was <2020-12-04 pią 19:37>, when Jakub Kicinski wrote:
> On Wed,  2 Dec 2020 22:47:09 +0100 Łukasz Stelmach wrote:
>> ASIX AX88796[1] is a versatile ethernet adapter chip, that can be
>> connected to a CPU with a 8/16-bit bus or with an SPI. This driver
>> supports SPI connection.
>> 

Before we begin let me emphisize the following sentence

>> The driver has been ported from the vendor kernel for ARTIK5[2]
>> boards.

This means, that there may be parts I am not very confident about. I am
not saying I don't take responsibility for them, far from that. But I am
more then happy, when someone points at them saying they make no
sense. When you ask - Why? And I say - I don't know. That means -
Please, be so kind and help me improve it. OK?

>> Several changes were made to adapt it to the current kernel which
>> include:
>> 
>> + updated DT configuration,
>> + clock configuration moved to DT,
>> + new timer, ethtool and gpio APIs,
>> + dev_* instead of pr_* and custom printk() wrappers,
>> + removed awkward vendor power managemtn.
>> + introduced ethtool tunable to control SPI compression
>> 
>> [1]
>> https://protect2.fireeye.com/v1/url?k=676ddfd4-38f6e6cb-676c549b-000babdfecba-4b1c0ca737b1deaa&q=1&e=0b28bac6-bda4-4cf1-8d38-c5c264b64aca&u=https%3A%2F%2Fwww.asix.com.tw%2Fproducts.php%3Fop%3DpItemdetail%26PItemID%3D104%3B65%3B86%26PLine%3D65
>> [2]
>> https://protect2.fireeye.com/v1/url?k=4148effe-1ed3d6e1-414964b1-000babdfecba-a257ebdf6f0e18f5&q=1&e=0b28bac6-bda4-4cf1-8d38-c5c264b64aca&u=https%3A%2F%2Fgit.tizen.org%2Fcgit%2Fprofile%2Fcommon%2Fplatform%2Fkernel%2Flinux-3.10-artik%2F
>> 
>> The other ax88796 driver is for NE2000 compatible AX88796L chip. These
>> chips are not compatible. Hence, two separate drivers are required.
>> 
>> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>
>> +	case ETHTOOL_SPI_COMPRESSION:
>> +		if (netif_running(ndev))
>> +			return -EBUSY;
>> +		if ((*(u32 *)data) != 1)
>> +			return -EINVAL;
>> +		ax_local->capabilities &= ~AX_CAP_COMP;
>> +		ax_local->capabilities |= (*(u32 *)data) == 1 ? AX_CAP_COMP : 0;
>
> Since you're just using a single bit of information please use 
> a private driver flag.
>

Done.

>> +	headroom = skb_headroom(skb);
>> +	tailroom = skb_tailroom(skb);
>> +	padlen = ((pkt_len + 3) & 0x7FC) - pkt_len;
>
> 	round_up(pkt_len, 4) - pkt_len;
>
>> +	tol_len = ((pkt_len + 3) & 0x7FC) +
>> +			TX_OVERHEAD + TX_EOP_SIZE + spi_len;
>
> Ditto
>

Done.

>> +	seq_num = ++ax_local->seq_num & 0x1F;
>> +
>> +	info = (struct tx_pkt_info *)skb->cb;
>> +	info->pkt_len = pkt_len;
>> +
>> +	if ((!skb_cloned(skb)) &&
>> +	    (headroom >= (TX_OVERHEAD + spi_len)) &&
>> +	    (tailroom >= (padlen + TX_EOP_SIZE))) {
>
>> +	} else {
>
> I think you can just use pskb_expand_head() instead of all this
>

Under construction.

>> +		tx_skb = alloc_skb(tol_len, GFP_KERNEL);
>> +		if (!tx_skb)
>> +			return NULL;
>> +
>> +		/* Write SPI TXQ header */
>> +		memcpy(skb_put(tx_skb, spi_len), ax88796c_tx_cmd_buf, spi_len);
>> +
>> +		info->seq_num = seq_num;
>> +		ax88796c_proc_tx_hdr(info, skb->ip_summed);
>> +
>> +		/* SOP and SEG header */
>> +		memcpy(skb_put(tx_skb, TX_OVERHEAD),
>> +		       &info->sop, TX_OVERHEAD);
>> +
>> +		/* Packet */
>> +		memcpy(skb_put(tx_skb, ((pkt_len + 3) & 0xFFFC)),
>> +		       skb->data, pkt_len);
>> +
>> +		/* EOP header */
>> +		memcpy(skb_put(tx_skb, TX_EOP_SIZE),
>> +		       &info->eop, TX_EOP_SIZE);
>> +
>> +		skb_unlink(skb, q);
>> +		dev_kfree_skb(skb);
>> +	}
>
>> +static void
>> +ax88796c_skb_return(struct ax88796c_device *ax_local, struct sk_buff *skb,
>> +		    struct rx_header *rxhdr)
>> +{
>> +	struct net_device *ndev = ax_local->ndev;
>> +	int status;
>> +
>> +	do {
>> +		if (!(ndev->features & NETIF_F_RXCSUM))
>> +			break;
>> +
>> +		/* checksum error bit is set */
>> +		if ((rxhdr->flags & RX_HDR3_L3_ERR) ||
>> +		    (rxhdr->flags & RX_HDR3_L4_ERR))
>> +			break;
>> +
>> +		/* Other types may be indicated by more than one bit. */
>> +		if ((rxhdr->flags & RX_HDR3_L4_TYPE_TCP) ||
>> +		    (rxhdr->flags & RX_HDR3_L4_TYPE_UDP))
>> +			skb->ip_summed = CHECKSUM_UNNECESSARY;
>> +	} while (0);
>> +
>> +	ax_local->stats.rx_packets++;
>> +	ax_local->stats.rx_bytes += skb->len;
>> +	skb->dev = ndev;
>> +
>> +	skb->truesize = skb->len + sizeof(struct sk_buff);
>
> Why do you modify truesize?
>

I don't know. Although uncommon, this appears in a few usb drivers, so I
didn't think much about it when I ported this code.

>> +	skb->protocol = eth_type_trans(skb, ax_local->ndev);
>> +
>> +	netif_info(ax_local, rx_status, ndev, "< rx, len %zu, type 0x%x\n",
>> +		   skb->len + sizeof(struct ethhdr), skb->protocol);
>> +
>> +	status = netif_rx_ni(skb);
>> +	if (status != NET_RX_SUCCESS)
>> +		netif_info(ax_local, rx_err, ndev,
>> +			   "netif_rx status %d\n", status);
>> +}
>> +
>> +static void
>> +ax88796c_rx_fixup(struct ax88796c_device *ax_local, struct sk_buff *rx_skb)
>> +{
>> +	struct rx_header *rxhdr = (struct rx_header *)rx_skb->data;
>> +	struct net_device *ndev = ax_local->ndev;
>> +	u16 len;
>> +
>> +	be16_to_cpus(&rxhdr->flags_len);
>> +	be16_to_cpus(&rxhdr->seq_lenbar);
>> +	be16_to_cpus(&rxhdr->flags);
>> +
>> +	if ((((short)rxhdr->flags_len) & RX_HDR1_PKT_LEN) !=
>> +			 (~((short)rxhdr->seq_lenbar) & 0x7FF)) {
>
> Why do you cast these values to signed types?
> Is the casting necessary at all?
>

It is not. Done.

>> +		netif_err(ax_local, rx_err, ndev, "Header error\n");
>> +
>> +		ax_local->stats.rx_frame_errors++;
>> +		kfree_skb(rx_skb);
>> +		return;
>> +	}
>> +
>> +	if ((rxhdr->flags_len & RX_HDR1_MII_ERR) ||
>> +	    (rxhdr->flags_len & RX_HDR1_CRC_ERR)) {
>> +		netif_err(ax_local, rx_err, ndev, "CRC or MII error\n");
>> +
>> +		ax_local->stats.rx_crc_errors++;
>> +		kfree_skb(rx_skb);
>> +		return;
>> +	}
>> +
>> +	len = rxhdr->flags_len & RX_HDR1_PKT_LEN;
>> +	if (netif_msg_pktdata(ax_local)) {
>> +		char pfx[IFNAMSIZ + 7];
>> +
>> +		snprintf(pfx, sizeof(pfx), "%s:     ", ndev->name);
>> +		netdev_info(ndev, "RX data, total len %d, packet len %d\n",
>> +			    rx_skb->len, len);
>> +
>> +		netdev_info(ndev, "  Dump RX packet header:");
>> +		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
>> +			       rx_skb->data, sizeof(*rxhdr), 0);
>> +
>> +		netdev_info(ndev, "  Dump RX packet:");
>> +		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
>> +			       rx_skb->data + sizeof(*rxhdr), len, 0);
>> +	}
>> +
>> +	skb_pull(rx_skb, sizeof(*rxhdr));
>> +	__pskb_trim(rx_skb, len);
>
> Why __pskb_trim? skb_trim() should do.
>

Done.

>> +	return ax88796c_skb_return(ax_local, rx_skb, rxhdr);
>
> please drop the "return", both caller and callee are void.
>

Done.

>> +}
>> +
>> +static int ax88796c_receive(struct net_device *ndev)
>> +{
>> +	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
>> +	struct skb_data *entry;
>> +	u16 w_count, pkt_len;
>> +	struct sk_buff *skb;
>> +	u8 pkt_cnt;
>> +
>> +	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
>> +
>> +	/* check rx packet and total word count */
>> +	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_RTWCR)
>> +		  | RTWCR_RX_LATCH, P0_RTWCR);
>> +
>> +	pkt_cnt = AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_PKT_MASK;
>> +	if (!pkt_cnt)
>> +		return 0;
>> +
>> +	pkt_len = AX_READ(&ax_local->ax_spi, P0_RCPHR) & 0x7FF;
>> +
>> +	w_count = ((pkt_len + 6 + 3) & 0xFFFC) >> 1;
>> +
>> +	skb = alloc_skb((w_count * 2), GFP_ATOMIC);
>
> netdev_alloc_skb()
>

Done.

>> +	if (!skb) {
>> +		AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_DISCARD, P0_RXBCR1);
>> +		return 0;
>> +	}
>> +	entry = (struct skb_data *)skb->cb;
>> +
>> +	AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_START | w_count, P0_RXBCR1);
>> +
>> +	axspi_read_rxq(&ax_local->ax_spi,
>> +		       skb_put(skb, w_count * 2), skb->len);
>> +
>> +	/* Check if rx bridge is idle */
>> +	if ((AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_RXB_IDLE) == 0) {
>> +		netif_err(ax_local, rx_err, ndev,
>> +			  "Rx Bridge is not idle\n");
>> +		AX_WRITE(&ax_local->ax_spi, RXBCR2_RXB_REINIT, P0_RXBCR2);
>> +
>> +		entry->state = rx_err;
>> +	} else {
>> +		entry->state = rx_done;
>> +	}
>> +
>> +	AX_WRITE(&ax_local->ax_spi, ISR_RXPKT, P0_ISR);
>> +
>> +	ax88796c_rx_fixup(ax_local, skb);
>> +
>> +	return 1;
>> +}
>
>> +static irqreturn_t ax88796c_interrupt(int irq, void *dev_instance)
>> +{
>> +	struct ax88796c_device *ax_local;
>> +	struct net_device *ndev;
>> +
>> +	ndev = dev_instance;
>> +	if (!ndev) {
>> +		pr_err("irq %d for unknown device.\n", irq);
>> +		return IRQ_RETVAL(0);
>> +	}
>> +	ax_local = to_ax88796c_device(ndev);
>> +
>> +	disable_irq_nosync(irq);
>> +
>> +	netif_dbg(ax_local, intr, ndev, "Interrupt occurred\n");
>> +
>> +	set_bit(EVENT_INTR, &ax_local->flags);
>> +	schedule_work(&ax_local->ax_work);
>> +
>> +	return IRQ_HANDLED;
>> +}
>
> Since you always punt to a workqueue did you consider just using
> threaded interrupts instead? 

Yes, and I have decided to stay with the workqueue. Interrupt
processing is not the only task performed in the workqueue. There is
also trasmission to the hardware, which may be quite slow (remember, it
is SPI), so it's better decoupled from syscalls

> Also you're not checking if this is actually your devices IRQ that
> triggered. You can't set IRQF_SHARED.

Fixed.

>> +static int
>> +ax88796c_open(struct net_device *ndev)
>> +{
>> +	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
>> +	unsigned long irq_flag = IRQF_SHARED;
>> +	int fc = AX_FC_NONE;
>> +	int ret;
>> +
>> +	ret = request_irq(ndev->irq, ax88796c_interrupt,
>> +			  irq_flag, ndev->name, ndev);
>> +	if (ret) {
>> +		netdev_err(ndev, "unable to get IRQ %d (errno=%d).\n",
>> +			   ndev->irq, ret);
>> +		return ret;
>> +	}
>> +
>> +	mutex_lock(&ax_local->spi_lock);
>> +
>> +	ret = ax88796c_soft_reset(ax_local);
>> +	if (ret < 0) {
>> +		mutex_unlock(&ax_local->spi_lock);
>> +		return ret;
>
> What frees the IRQ?
>

Fixed.

>> +	}
>> +	ax_local->seq_num = 0x1f;
>> +
>> +	ax88796c_set_mac_addr(ndev);
>> +	ax88796c_set_csums(ax_local);
>> +
>> +	/* Disable stuffing packet */
>> +	AX_WRITE(&ax_local->ax_spi,
>> +		 AX_READ(&ax_local->ax_spi, P1_RXBSPCR)
>> +		 & ~RXBSPCR_STUF_ENABLE, P1_RXBSPCR);
>
> Please use a temporary variable or create a RMW helper.
>
>> +	/* Enable RX packet process */
>> +	AX_WRITE(&ax_local->ax_spi, RPPER_RXEN, P1_RPPER);
>> +
>> +	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_FER)
>> +		 | FER_RXEN | FER_TXEN | FER_BSWAP | FER_IRQ_PULL, P0_FER);
>
> Ditto. etc.
>

Done x2.

>> +	ndev = devm_alloc_etherdev(&spi->dev, sizeof(*ax_local));
>> +	if (!ndev)
>> +		return -ENOMEM;
>> +
>> +	SET_NETDEV_DEV(ndev, &spi->dev);
>> +
>> +	ax_local = to_ax88796c_device(ndev);
>> +	memset(ax_local, 0, sizeof(*ax_local));
>
> No need to zero out netdev priv, it's zalloced.
>

Fixed.

>> +	mutex_lock(&ax_local->spi_lock);
>> +
>> +	/* ax88796c gpio reset */
>> +	ax88796c_hard_reset(ax_local);
>> +
>> +	/* Reset AX88796C */
>> +	ret = ax88796c_soft_reset(ax_local);
>> +	if (ret < 0) {
>> +		ret = -ENODEV;
>> +		goto err;
>> +	}
>> +	/* Check board revision */
>> +	temp = AX_READ(&ax_local->ax_spi, P2_CRIR);
>> +	if ((temp & 0xF) != 0x0) {
>> +		dev_err(&spi->dev, "spi read failed: %d\n", temp);
>> +		ret = -ENODEV;
>> +		goto err;
>> +	}
>
> These jump out without releasing the lock.
>

Fixed.

>> +	/* Disable power saving */
>> +	AX_WRITE(&ax_local->ax_spi, (AX_READ(&ax_local->ax_spi, P0_PSCR)
>> +				     & PSCR_PS_MASK) | PSCR_PS_D0, P0_PSCR);
>
> This is asking for a temporary variable or a RMW helper.
>
>> +	u8			plat_endian;
>> +		#define PLAT_LITTLE_ENDIAN	0
>> +		#define PLAT_BIG_ENDIAN		1
>
> Why do you store this little nugget of information?
>

I don't know*. The hardware enables endianness detection by providing a
constant value (0x1234) in one of its registers. Unfortunately I don't
have a big-endian board with this chip to check if it is necessary to
alter AX_READ/AX_WRITE in any way.

>> +/* Tx headers structure */
>> +struct tx_sop_header {
>> +	/* bit 15-11: flags, bit 10-0: packet length */
>> +	u16 flags_len;
>> +	/* bit 15-11: sequence number, bit 11-0: packet length bar */
>> +	u16 seq_lenbar;
>> +} __packed;
>> +
>> +struct tx_segment_header {
>> +	/* bit 15-14: flags, bit 13-11: segment number */
>> +	/* bit 10-0: segment length */
>> +	u16 flags_seqnum_seglen;
>> +	/* bit 15-14: end offset, bit 13-11: start offset */
>> +	/* bit 10-0: segment length bar */
>> +	u16 eo_so_seglenbar;
>> +} __packed;
>> +
>> +struct tx_eop_header {
>> +	/* bit 15-11: sequence number, bit 10-0: packet length */
>> +	u16 seq_len;
>> +	/* bit 15-11: sequence number bar, bit 10-0: packet length bar */
>> +	u16 seqbar_lenbar;
>> +} __packed;
>> +
>> +struct tx_pkt_info {
>> +	struct tx_sop_header sop;
>> +	struct tx_segment_header seg;
>> +	struct tx_eop_header eop;
>> +	u16 pkt_len;
>> +	u16 seq_num;
>> +} __packed;
>> +
>> +/* Rx headers structure */
>> +struct rx_header {
>> +	u16 flags_len;
>> +	u16 seq_lenbar;
>> +	u16 flags;
>> +} __packed;
>
> These all look like multiple of 2 bytes. Why do they need to be packed?
>

These are structures sent to and returned from the hardware. They are
prepended and appended to the network packets. I think it is good to
keep them packed, so compilers won't try any tricks.

>> +u16 axspi_read_reg(struct axspi_data *ax_spi, u8 reg)
>> +{
>> +	int ret;
>> +	int len = ax_spi->comp ? 3 : 4;
>> +
>> +	ax_spi->cmd_buf[0] = 0x03;	/* OP code read register */
>> +	ax_spi->cmd_buf[1] = reg;	/* register address */
>> +	ax_spi->cmd_buf[2] = 0xFF;	/* dumy cycle */
>> +	ax_spi->cmd_buf[3] = 0xFF;	/* dumy cycle */
>> +	ret = spi_write_then_read(ax_spi->spi,
>> +				  ax_spi->cmd_buf, len,
>> +				  ax_spi->rx_buf, 2);
>> +	if (ret)
>> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
>> +	else
>> +		le16_to_cpus(ax_spi->rx_buf);
>> +
>> +	return *(u16 *)ax_spi->rx_buf;
>
> No need to return some specific pattern on failure? Like 0xffff?
>

All registers are 16 bit wide. I am afraid it isn't safe to assume that
there is a 16 bit value we could use. Chances that SPI goes south are
pretty slim. And if it does, there isn't much more than reporting an
error we can do about it anyway.

One thing I can think of is to change axspi_* to (s32), return -1,
somehow (how?) shutdown the device in AX_*.
Jakub Kicinski Dec. 16, 2020, 1:46 a.m. UTC | #3
On Wed, 16 Dec 2020 01:42:03 +0100 Lukasz Stelmach wrote:
> >> +	ax_local->stats.rx_packets++;
> >> +	ax_local->stats.rx_bytes += skb->len;
> >> +	skb->dev = ndev;
> >> +
> >> +	skb->truesize = skb->len + sizeof(struct sk_buff);  
> >
> > Why do you modify truesize?
> >  
> 
> I don't know. Although uncommon, this appears in a few usb drivers, so I
> didn't think much about it when I ported this code.

I'd guess they do aggregation. I wouldn't touch it in your driver.

>> Since you always punt to a workqueue did you consider just using
>> threaded interrupts instead?   
> 
> Yes, and I have decided to stay with the workqueue. Interrupt
> processing is not the only task performed in the workqueue. There is
> also trasmission to the hardware, which may be quite slow (remember, it
> is SPI), so it's better decoupled from syscalls

I see, and since the device can't do RX and TX simultaneously (IIRC),
that makes sense.

> >> +	u8			plat_endian;
> >> +		#define PLAT_LITTLE_ENDIAN	0
> >> +		#define PLAT_BIG_ENDIAN		1  
> >
> > Why do you store this little nugget of information?
> >  
> 
> I don't know*. The hardware enables endianness detection by providing a
> constant value (0x1234) in one of its registers. Unfortunately I don't
> have a big-endian board with this chip to check if it is necessary to
> alter AX_READ/AX_WRITE in any way.

Yeah, may be hard to tell what magic the device is doing.
I was mostly saying that you don't seem to use this information,
so the member of the struct can be removed IIRC.

> > These all look like multiple of 2 bytes. Why do they need to be packed?
> >  
> 
> These are structures sent to and returned from the hardware. They are
> prepended and appended to the network packets. I think it is good to
> keep them packed, so compilers won't try any tricks.

Compilers can't play tricks on memory layout of structures, the
standard is pretty strict about that. Otherwise ABIs would never work.
We prefer not to unnecessarily pack structures in the neworking code,
because it generates byte by byte loads on architectures which can't 
do unaligned accesses.

> > No need to return some specific pattern on failure? Like 0xffff?
> >  
> 
> All registers are 16 bit wide. I am afraid it isn't safe to assume that
> there is a 16 bit value we could use. Chances that SPI goes south are
> pretty slim. And if it does, there isn't much more than reporting an
> error we can do about it anyway.
> 
> One thing I can think of is to change axspi_* to (s32), return -1,
> somehow (how?) shutdown the device in AX_*.

I'm mostly concerned about potentially random data left over in the
buffer. Seems like it could lead to hard to repro bugs. Hence the
suggestion to return a constant of your choosing on error, doesn't
really matter what as long as it's a known constant.
Łukasz Stelmach Dec. 16, 2020, 12:21 p.m. UTC | #4
It was <2020-12-15 wto 17:46>, when Jakub Kicinski wrote:
> On Wed, 16 Dec 2020 01:42:03 +0100 Lukasz Stelmach wrote:
>>>> +	ax_local->stats.rx_packets++;
>>>> +	ax_local->stats.rx_bytes += skb->len;
>>>> +	skb->dev = ndev;
>>>> +
>>>> +	skb->truesize = skb->len + sizeof(struct sk_buff);  
>>>
>>> Why do you modify truesize?
>>>  
>> 
>> I don't know. Although uncommon, this appears in a few usb drivers, so I
>> didn't think much about it when I ported this code.
>
> I'd guess they do aggregation. I wouldn't touch it in your driver.
>

Removed.

>>>> +	u8			plat_endian;
>>>> +		#define PLAT_LITTLE_ENDIAN	0
>>>> +		#define PLAT_BIG_ENDIAN		1  
>>>
>>> Why do you store this little nugget of information?
>>>  
>> 
>> I don't know*. The hardware enables endianness detection by providing a
>> constant value (0x1234) in one of its registers. Unfortunately I don't
>> have a big-endian board with this chip to check if it is necessary to
>> alter AX_READ/AX_WRITE in any way.
>
> Yeah, may be hard to tell what magic the device is doing.
> I was mostly saying that you don't seem to use this information,
> so the member of the struct can be removed IIRC.
>

Removed.

>>> These all look like multiple of 2 bytes. Why do they need to be packed?
>> 
>> These are structures sent to and returned from the hardware. They are
>> prepended and appended to the network packets. I think it is good to
>> keep them packed, so compilers won't try any tricks.
>
> Compilers can't play tricks on memory layout of structures, the
> standard is pretty strict about that. Otherwise ABIs would never work.
> We prefer not to unnecessarily pack structures in the neworking code,
> because it generates byte by byte loads on architectures which can't 
> do unaligned accesses.

Indeed, a struct of three u16 is 6 bytes long. I was worried it may be
rounded up to 8. Removed.

>>> No need to return some specific pattern on failure? Like 0xffff?
>> 
>> All registers are 16 bit wide. I am afraid it isn't safe to assume that
>> there is a 16 bit value we could use. Chances that SPI goes south are
>> pretty slim. And if it does, there isn't much more than reporting an
>> error we can do about it anyway.
>> 
>> One thing I can think of is to change axspi_* to (s32), return -1,
>> somehow (how?) shutdown the device in AX_*.
>
> I'm mostly concerned about potentially random data left over in the
> buffer. Seems like it could lead to hard to repro bugs. Hence the
> suggestion to return a constant of your choosing on error, doesn't
> really matter what as long as it's a known constant.

I see, that makes sense, indeed.

So, the only thing that's left is pskb_expand_head(). I need to wrap my
head around it. Can you tell me how a cloned skb is different and why
there may be separate branch for it?

Thank you.
Jakub Kicinski Dec. 16, 2020, 4:13 p.m. UTC | #5
On Wed, 16 Dec 2020 13:21:52 +0100 Lukasz Stelmach wrote:
> So, the only thing that's left is pskb_expand_head(). I need to wrap my
> head around it. Can you tell me how a cloned skb is different and why
> there may be separate branch for it?

I think this driver needs to prepend and append some info to the packet
data, right? Cloned skb is sharing the data with another skb, the
metadata is separate but the packet data is shared, so you can't modify
the data, you need to do a copy of the data. pskb_expand_head() should
take care of cloned skbs so you can just call it upfront and it will
make sure the skb is the right geometry for you.

BTW you should set netdev->needed_headroom and netdev->needed_tailroom
to the correct values so the stack pre-allocates the needed spaces,
when it can.
Łukasz Stelmach Dec. 17, 2020, 11:46 a.m. UTC | #6
It was <2020-12-16 śro 08:13>, when Jakub Kicinski wrote:
> On Wed, 16 Dec 2020 13:21:52 +0100 Lukasz Stelmach wrote:
>> So, the only thing that's left is pskb_expand_head(). I need to wrap my
>> head around it. Can you tell me how a cloned skb is different and why
>> there may be separate branch for it?
>
> I think this driver needs to prepend and append some info to the packet
> data, right? Cloned skb is sharing the data with another skb, the
> metadata is separate but the packet data is shared, so you can't modify
> the data, you need to do a copy of the data. pskb_expand_head() should
> take care of cloned skbs so you can just call it upfront and it will
> make sure the skb is the right geometry for you.
>
> BTW you should set netdev->needed_headroom and netdev->needed_tailroom

Done.

> to the correct values so the stack pre-allocates the needed spaces,
> when it can.

Yes, I fonud these. However, I am not sure setting needed_tailroom has
any effect. In many places where alloc_skb() is called needed_headrom
and hard_header_len are refered to via the LL_RESERVED_SPACE macro. But
the macro does not refer to needed_tailroom. Once (f5184d267c1a ("net:
Allow netdevices to specify needed head/tailroom") there was
LL_ALLOCATED_SPACE macro, but but it was removed in 56c978f1da1f ("net:
Remove LL_ALLOCATED_SPACE"). And now only some protocols refer to
needet_tailroom.

BTW. What is hard_header_len for? Is it the length of the link layer
header? Considering "my" hardware requires some headers with each
packet, I find hard_headr_len name a bit confusing.

I will be sending v9 in a minute or two.

Kind regards,
Jakub Kicinski Dec. 17, 2020, 5:06 p.m. UTC | #7
On Thu, 17 Dec 2020 12:46:57 +0100 Lukasz Stelmach wrote:
> > to the correct values so the stack pre-allocates the needed spaces,
> > when it can.  
> 
> Yes, I fonud these. However, I am not sure setting needed_tailroom has
> any effect. In many places where alloc_skb() is called needed_headrom
> and hard_header_len are refered to via the LL_RESERVED_SPACE macro. But
> the macro does not refer to needed_tailroom. Once (f5184d267c1a ("net:
> Allow netdevices to specify needed head/tailroom") there was
> LL_ALLOCATED_SPACE macro, but but it was removed in 56c978f1da1f ("net:
> Remove LL_ALLOCATED_SPACE"). And now only some protocols refer to
> needet_tailroom.

Yeah, tailroom is used a lot less often. Only really crappy HW requires
it.

> BTW. What is hard_header_len for? Is it the length of the link layer
> header? Considering "my" hardware requires some headers with each
> packet, I find hard_headr_len name a bit confusing.

Yup, L2 headers, not hardware. Not sure why "hard" was chosen, that must
have happened way back.
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 14b8ec0bb58b..29088970a9cc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2812,6 +2812,12 @@  S:	Maintained
 F:	Documentation/hwmon/asc7621.rst
 F:	drivers/hwmon/asc7621.c
 
+ASIX AX88796C SPI ETHERNET ADAPTER
+M:	Łukasz Stelmach <l.stelmach@samsung.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/net/asix,ax88796c.yaml
+F:	drivers/net/ethernet/asix/ax88796c_*
+
 ASPEED PINCTRL DRIVERS
 M:	Andrew Jeffery <andrew@aj.id.au>
 L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
diff --git a/drivers/net/ethernet/Kconfig b/drivers/net/ethernet/Kconfig
index de50e8b9e656..f3b218e45ea5 100644
--- a/drivers/net/ethernet/Kconfig
+++ b/drivers/net/ethernet/Kconfig
@@ -32,6 +32,7 @@  source "drivers/net/ethernet/apm/Kconfig"
 source "drivers/net/ethernet/apple/Kconfig"
 source "drivers/net/ethernet/aquantia/Kconfig"
 source "drivers/net/ethernet/arc/Kconfig"
+source "drivers/net/ethernet/asix/Kconfig"
 source "drivers/net/ethernet/atheros/Kconfig"
 source "drivers/net/ethernet/aurora/Kconfig"
 source "drivers/net/ethernet/broadcom/Kconfig"
diff --git a/drivers/net/ethernet/Makefile b/drivers/net/ethernet/Makefile
index f8f38dcb5f8a..9eb368d93607 100644
--- a/drivers/net/ethernet/Makefile
+++ b/drivers/net/ethernet/Makefile
@@ -18,6 +18,7 @@  obj-$(CONFIG_NET_XGENE) += apm/
 obj-$(CONFIG_NET_VENDOR_APPLE) += apple/
 obj-$(CONFIG_NET_VENDOR_AQUANTIA) += aquantia/
 obj-$(CONFIG_NET_VENDOR_ARC) += arc/
+obj-$(CONFIG_NET_VENDOR_ASIX) += asix/
 obj-$(CONFIG_NET_VENDOR_ATHEROS) += atheros/
 obj-$(CONFIG_NET_VENDOR_AURORA) += aurora/
 obj-$(CONFIG_NET_VENDOR_CADENCE) += cadence/
diff --git a/drivers/net/ethernet/asix/Kconfig b/drivers/net/ethernet/asix/Kconfig
new file mode 100644
index 000000000000..eed02453314c
--- /dev/null
+++ b/drivers/net/ethernet/asix/Kconfig
@@ -0,0 +1,35 @@ 
+#
+# Asix network device configuration
+#
+
+config NET_VENDOR_ASIX
+	bool "Asix devices"
+	default y
+	help
+	  If you have a network (Ethernet, non-USB, not NE2000 compatible)
+	  interface based on a chip from ASIX, say Y.
+
+if NET_VENDOR_ASIX
+
+config SPI_AX88796C
+	tristate "Asix AX88796C-SPI support"
+	select PHYLIB
+	depends on SPI
+	depends on GPIOLIB
+	help
+	  Say Y here if you intend to use ASIX AX88796C attached in SPI mode.
+
+config SPI_AX88796C_COMPRESSION
+	bool "SPI transfer compression"
+	default n
+	depends on SPI_AX88796C
+	help
+	  Say Y here to enable SPI transfer compression. It saves up
+	  to 24 dummy cycles during each transfer which may noticeably
+	  speed up short transfers. This sets the default value that is
+	  inherited by network interfaces during probe. It can be
+	  changed at run time via spi-compression ethtool tunable.
+
+	  If unsure say N.
+
+endif # NET_VENDOR_ASIX
diff --git a/drivers/net/ethernet/asix/Makefile b/drivers/net/ethernet/asix/Makefile
new file mode 100644
index 000000000000..0bfbbb042634
--- /dev/null
+++ b/drivers/net/ethernet/asix/Makefile
@@ -0,0 +1,6 @@ 
+#
+# Makefile for the Asix network device drivers.
+#
+
+obj-$(CONFIG_SPI_AX88796C) += ax88796c.o
+ax88796c-y := ax88796c_main.o ax88796c_ioctl.o ax88796c_spi.o
diff --git a/drivers/net/ethernet/asix/ax88796c_ioctl.c b/drivers/net/ethernet/asix/ax88796c_ioctl.c
new file mode 100644
index 000000000000..941c2ff2c766
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_ioctl.c
@@ -0,0 +1,221 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#define pr_fmt(fmt)	"ax88796c: " fmt
+
+#include <linux/bitmap.h>
+#include <linux/iopoll.h>
+#include <linux/phy.h>
+#include <linux/netdevice.h>
+
+#include "ax88796c_main.h"
+#include "ax88796c_ioctl.h"
+
+static void
+ax88796c_get_drvinfo(struct net_device *ndev, struct ethtool_drvinfo *info)
+{
+	/* Inherit standard device info */
+	strncpy(info->driver, DRV_NAME, sizeof(info->driver));
+}
+
+static u32 ax88796c_get_msglevel(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	return ax_local->msg_enable;
+}
+
+static void ax88796c_set_msglevel(struct net_device *ndev, u32 level)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	ax_local->msg_enable = level;
+}
+
+static void
+ax88796c_get_pauseparam(struct net_device *ndev, struct ethtool_pauseparam *pause)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	pause->tx_pause = !!(ax_local->flowctrl & AX_FC_TX);
+	pause->rx_pause = !!(ax_local->flowctrl & AX_FC_RX);
+	pause->autoneg = (ax_local->flowctrl & AX_FC_ANEG) ?
+		AUTONEG_ENABLE :
+		AUTONEG_DISABLE;
+}
+
+static int
+ax88796c_set_pauseparam(struct net_device *ndev, struct ethtool_pauseparam *pause)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	int fc;
+
+	/* The following logic comes from phylink_ethtool_set_pauseparam() */
+	fc = pause->tx_pause ? AX_FC_TX : 0;
+	fc |= pause->rx_pause ? AX_FC_RX : 0;
+	fc |= pause->autoneg ? AX_FC_ANEG : 0;
+
+	ax_local->flowctrl = fc;
+
+	if (pause->autoneg) {
+		phy_set_asym_pause(ax_local->phydev, pause->tx_pause,
+				   pause->rx_pause);
+	} else {
+		int maccr = 0;
+
+		phy_set_asym_pause(ax_local->phydev, 0, 0);
+		maccr |= (ax_local->flowctrl & AX_FC_RX) ? MACCR_RXFC_ENABLE : 0;
+		maccr |= (ax_local->flowctrl & AX_FC_TX) ? MACCR_TXFC_ENABLE : 0;
+
+		mutex_lock(&ax_local->spi_lock);
+
+		maccr |= AX_READ(&ax_local->ax_spi, P0_MACCR) &
+			~(MACCR_TXFC_ENABLE | MACCR_RXFC_ENABLE);
+		AX_WRITE(&ax_local->ax_spi, maccr, P0_MACCR);
+
+		mutex_unlock(&ax_local->spi_lock);
+	}
+
+	return 0;
+}
+
+static int ax88796c_get_regs_len(struct net_device *ndev)
+{
+	return AX88796C_REGDUMP_LEN + AX88796C_PHY_REGDUMP_LEN;
+}
+
+static void
+ax88796c_get_regs(struct net_device *ndev, struct ethtool_regs *regs, void *_p)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	int offset, i;
+	u16 *p = _p;
+
+	memset(p, 0, ax88796c_get_regs_len(ndev));
+
+	mutex_lock(&ax_local->spi_lock);
+
+	for (offset = 0; offset < AX88796C_REGDUMP_LEN; offset += 2) {
+		if (!test_bit(offset / 2, ax88796c_no_regs_mask))
+			*p = AX_READ(&ax_local->ax_spi, offset);
+		p++;
+	}
+
+	mutex_unlock(&ax_local->spi_lock);
+
+	for (i = 0; i < AX88796C_PHY_REGDUMP_LEN / 2; i++) {
+		*p = phy_read(ax_local->phydev, i);
+		p++;
+	}
+}
+
+static int
+ax88796c_set_tunable(struct net_device *ndev, const struct ethtool_tunable *tuna,
+		     const void *data)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	switch (tuna->id) {
+	case ETHTOOL_SPI_COMPRESSION:
+		if (netif_running(ndev))
+			return -EBUSY;
+		if ((*(u32 *)data) != 1)
+			return -EINVAL;
+		ax_local->capabilities &= ~AX_CAP_COMP;
+		ax_local->capabilities |= (*(u32 *)data) == 1 ? AX_CAP_COMP : 0;
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static int
+ax88796c_get_tunable(struct net_device *ndev, const struct ethtool_tunable *tuna,
+		     void *data)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	switch (tuna->id) {
+	case ETHTOOL_SPI_COMPRESSION:
+		*(u32 *)data = !!(ax_local->ax_spi.comp & AX_CAP_COMP);
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+int ax88796c_mdio_read(struct mii_bus *mdiobus, int phy_id, int loc)
+{
+	struct ax88796c_device *ax_local = mdiobus->priv;
+	int ret;
+
+	mutex_lock(&ax_local->spi_lock);
+	AX_WRITE(&ax_local->ax_spi, MDIOCR_RADDR(loc)
+			| MDIOCR_FADDR(phy_id) | MDIOCR_READ, P2_MDIOCR);
+
+	ret = read_poll_timeout(AX_READ, ret,
+				(ret != 0),
+				0, jiffies_to_usecs(HZ / 100), false,
+				&ax_local->ax_spi, P2_MDIOCR);
+	if (!ret)
+		ret = AX_READ(&ax_local->ax_spi, P2_MDIODR);
+
+	mutex_unlock(&ax_local->spi_lock);
+
+	return ret;
+}
+
+int
+ax88796c_mdio_write(struct mii_bus *mdiobus, int phy_id, int loc, u16 val)
+{
+	struct ax88796c_device *ax_local = mdiobus->priv;
+	int ret;
+
+	mutex_lock(&ax_local->spi_lock);
+	AX_WRITE(&ax_local->ax_spi, val, P2_MDIODR);
+
+	AX_WRITE(&ax_local->ax_spi,
+		 MDIOCR_RADDR(loc) | MDIOCR_FADDR(phy_id)
+		 | MDIOCR_WRITE, P2_MDIOCR);
+
+	ret = read_poll_timeout(AX_READ, ret,
+				((ret & MDIOCR_VALID) != 0), 0,
+				jiffies_to_usecs(HZ / 100), false,
+				&ax_local->ax_spi, P2_MDIOCR);
+	mutex_unlock(&ax_local->spi_lock);
+
+	return ret;
+}
+
+const struct ethtool_ops ax88796c_ethtool_ops = {
+	.get_drvinfo		= ax88796c_get_drvinfo,
+	.get_link		= ethtool_op_get_link,
+	.get_msglevel		= ax88796c_get_msglevel,
+	.set_msglevel		= ax88796c_set_msglevel,
+	.get_link_ksettings	= phy_ethtool_get_link_ksettings,
+	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
+	.nway_reset		= phy_ethtool_nway_reset,
+	.get_pauseparam		= ax88796c_get_pauseparam,
+	.set_pauseparam		= ax88796c_set_pauseparam,
+	.get_regs_len		= ax88796c_get_regs_len,
+	.get_regs		= ax88796c_get_regs,
+	.get_tunable		= ax88796c_get_tunable,
+	.set_tunable		= ax88796c_set_tunable,};
+
+int ax88796c_ioctl(struct net_device *ndev, struct ifreq *ifr, int cmd)
+{
+	int ret;
+
+	ret = phy_mii_ioctl(ndev->phydev, ifr, cmd);
+
+	return ret;
+}
diff --git a/drivers/net/ethernet/asix/ax88796c_ioctl.h b/drivers/net/ethernet/asix/ax88796c_ioctl.h
new file mode 100644
index 000000000000..34d2a7dcc5ef
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_ioctl.h
@@ -0,0 +1,26 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#ifndef _AX88796C_IOCTL_H
+#define _AX88796C_IOCTL_H
+
+#include <linux/ethtool.h>
+#include <linux/netdevice.h>
+
+#include "ax88796c_main.h"
+
+extern const struct ethtool_ops ax88796c_ethtool_ops;
+
+bool ax88796c_check_power(const struct ax88796c_device *ax_local);
+bool ax88796c_check_power_and_wake(struct ax88796c_device *ax_local);
+void ax88796c_set_power_saving(struct ax88796c_device *ax_local, u8 ps_level);
+int ax88796c_mdio_read(struct mii_bus *mdiobus, int phy_id, int loc);
+int ax88796c_mdio_write(struct mii_bus *mdiobus, int phy_id, int loc, u16 val);
+int ax88796c_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
+
+#endif
diff --git a/drivers/net/ethernet/asix/ax88796c_main.c b/drivers/net/ethernet/asix/ax88796c_main.c
new file mode 100644
index 000000000000..43096e8c2448
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_main.c
@@ -0,0 +1,1127 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#define pr_fmt(fmt)	"ax88796c: " fmt
+
+#include "ax88796c_main.h"
+#include "ax88796c_ioctl.h"
+
+#include <linux/bitmap.h>
+#include <linux/etherdevice.h>
+#include <linux/iopoll.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+#include <linux/spi/spi.h>
+
+static int comp = IS_ENABLED(CONFIG_SPI_AX88796C_COMPRESSION);
+static int msg_enable = NETIF_MSG_PROBE |
+			NETIF_MSG_LINK |
+			NETIF_MSG_RX_ERR |
+			NETIF_MSG_TX_ERR;
+
+static char *no_regs_list = "80018001,e1918001,8001a001,fc0d0000";
+unsigned long ax88796c_no_regs_mask[AX88796C_REGDUMP_LEN / (sizeof(unsigned long) * 8)];
+
+module_param(msg_enable, int, 0444);
+MODULE_PARM_DESC(msg_enable, "Message mask (see linux/netdevice.h for bitmap)");
+
+static int ax88796c_soft_reset(struct ax88796c_device *ax_local)
+{
+	u16 temp;
+	int ret;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	AX_WRITE(&ax_local->ax_spi, PSR_RESET, P0_PSR);
+	AX_WRITE(&ax_local->ax_spi, PSR_RESET_CLR, P0_PSR);
+
+	ret = read_poll_timeout(AX_READ, ret,
+				(ret & PSR_DEV_READY),
+				0, jiffies_to_usecs(160 * HZ / 1000), false,
+				&ax_local->ax_spi, P0_PSR);
+	if (ret)
+		return ret;
+
+	temp = AX_READ(&ax_local->ax_spi, P4_SPICR);
+	if (ax_local->capabilities & AX_CAP_COMP) {
+		AX_WRITE(&ax_local->ax_spi,
+			 (temp | SPICR_RCEN | SPICR_QCEN), P4_SPICR);
+		ax_local->ax_spi.comp = 1;
+	} else {
+		AX_WRITE(&ax_local->ax_spi,
+			 (temp & ~(SPICR_RCEN | SPICR_QCEN)), P4_SPICR);
+		ax_local->ax_spi.comp = 0;
+	}
+
+	return 0;
+}
+
+static int ax88796c_reload_eeprom(struct ax88796c_device *ax_local)
+{
+	int ret;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	AX_WRITE(&ax_local->ax_spi, EECR_RELOAD, P3_EECR);
+
+	ret = read_poll_timeout(AX_READ, ret,
+				(ret & PSR_DEV_READY),
+				0, jiffies_to_usecs(2 * HZ / 1000), false,
+				&ax_local->ax_spi, P0_PSR);
+	if (ret) {
+		dev_err(&ax_local->spi->dev,
+			"timeout waiting for reload eeprom\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void ax88796c_set_hw_multicast(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	int mc_count = netdev_mc_count(ndev);
+	u16 rx_ctl = RXCR_AB;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	memset(ax_local->multi_filter, 0, AX_MCAST_FILTER_SIZE);
+
+	if (ndev->flags & IFF_PROMISC) {
+		rx_ctl |= RXCR_PRO;
+
+	} else if (ndev->flags & IFF_ALLMULTI || mc_count > AX_MAX_MCAST) {
+		rx_ctl |= RXCR_AMALL;
+
+	} else if (mc_count == 0) {
+		/* just broadcast and directed */
+	} else {
+		u32 crc_bits;
+		int i;
+		struct netdev_hw_addr *ha;
+
+		netdev_for_each_mc_addr(ha, ndev) {
+			crc_bits = ether_crc(ETH_ALEN, ha->addr);
+			ax_local->multi_filter[crc_bits >> 29] |=
+						(1 << ((crc_bits >> 26) & 7));
+		}
+
+		for (i = 0; i < 4; i++) {
+			AX_WRITE(&ax_local->ax_spi,
+				 ((ax_local->multi_filter[i * 2 + 1] << 8) |
+				  ax_local->multi_filter[i * 2]), P3_MFAR(i));
+		}
+	}
+
+	AX_WRITE(&ax_local->ax_spi, rx_ctl, P2_RXCR);
+}
+
+static void ax88796c_set_mac_addr(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	AX_WRITE(&ax_local->ax_spi, ((u16)(ndev->dev_addr[4] << 8) |
+			(u16)ndev->dev_addr[5]), P3_MACASR0);
+	AX_WRITE(&ax_local->ax_spi, ((u16)(ndev->dev_addr[2] << 8) |
+			(u16)ndev->dev_addr[3]), P3_MACASR1);
+	AX_WRITE(&ax_local->ax_spi, ((u16)(ndev->dev_addr[0] << 8) |
+			(u16)ndev->dev_addr[1]), P3_MACASR2);
+}
+
+static void ax88796c_load_mac_addr(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	u16 temp;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	/* Try the device tree first */
+	if (!eth_platform_get_mac_address(&ax_local->spi->dev, ndev->dev_addr) &&
+	    is_valid_ether_addr(ndev->dev_addr)) {
+		if (netif_msg_probe(ax_local))
+			dev_info(&ax_local->spi->dev,
+				 "MAC address read from device tree\n");
+		return;
+	}
+
+	/* Read the MAC address from AX88796C */
+	temp = AX_READ(&ax_local->ax_spi, P3_MACASR0);
+	ndev->dev_addr[5] = (u8)temp;
+	ndev->dev_addr[4] = (u8)(temp >> 8);
+
+	temp = AX_READ(&ax_local->ax_spi, P3_MACASR1);
+	ndev->dev_addr[3] = (u8)temp;
+	ndev->dev_addr[2] = (u8)(temp >> 8);
+
+	temp = AX_READ(&ax_local->ax_spi, P3_MACASR2);
+	ndev->dev_addr[1] = (u8)temp;
+	ndev->dev_addr[0] = (u8)(temp >> 8);
+
+	if (is_valid_ether_addr(ndev->dev_addr)) {
+		if (netif_msg_probe(ax_local))
+			dev_info(&ax_local->spi->dev,
+				 "MAC address read from ASIX chip\n");
+		return;
+	}
+
+	/* Use random address if none found */
+	if (netif_msg_probe(ax_local))
+		dev_info(&ax_local->spi->dev, "Use random MAC address\n");
+	eth_hw_addr_random(ndev);
+}
+
+static void ax88796c_proc_tx_hdr(struct tx_pkt_info *info, u8 ip_summed)
+{
+	u16 pkt_len_bar = (~info->pkt_len & TX_HDR_SOP_PKTLENBAR);
+
+	/* Prepare SOP header */
+	info->sop.flags_len = info->pkt_len |
+		((ip_summed == CHECKSUM_NONE) ||
+		 (ip_summed == CHECKSUM_UNNECESSARY) ? TX_HDR_SOP_DICF : 0);
+
+	info->sop.seq_lenbar = ((info->seq_num << 11) & TX_HDR_SOP_SEQNUM)
+				| pkt_len_bar;
+	cpu_to_be16s(&info->sop.flags_len);
+	cpu_to_be16s(&info->sop.seq_lenbar);
+
+	/* Prepare Segment header */
+	info->seg.flags_seqnum_seglen = TX_HDR_SEG_FS | TX_HDR_SEG_LS
+						| info->pkt_len;
+
+	info->seg.eo_so_seglenbar = pkt_len_bar;
+
+	cpu_to_be16s(&info->seg.flags_seqnum_seglen);
+	cpu_to_be16s(&info->seg.eo_so_seglenbar);
+
+	/* Prepare EOP header */
+	info->eop.seq_len = ((info->seq_num << 11) &
+			     TX_HDR_EOP_SEQNUM) | info->pkt_len;
+	info->eop.seqbar_lenbar = ((~info->seq_num << 11) &
+				   TX_HDR_EOP_SEQNUMBAR) | pkt_len_bar;
+
+	cpu_to_be16s(&info->eop.seq_len);
+	cpu_to_be16s(&info->eop.seqbar_lenbar);
+}
+
+static int
+ax88796c_check_free_pages(struct ax88796c_device *ax_local, u8 need_pages)
+{
+	u8 free_pages;
+	u16 tmp;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	free_pages = AX_READ(&ax_local->ax_spi, P0_TFBFCR) & TX_FREEBUF_MASK;
+	if (free_pages < need_pages) {
+		/* schedule free page interrupt */
+		tmp = AX_READ(&ax_local->ax_spi, P0_TFBFCR)
+				& TFBFCR_SCHE_FREE_PAGE;
+		AX_WRITE(&ax_local->ax_spi, tmp | TFBFCR_TX_PAGE_SET |
+				TFBFCR_SET_FREE_PAGE(need_pages),
+				P0_TFBFCR);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static struct sk_buff *
+ax88796c_tx_fixup(struct net_device *ndev, struct sk_buff_head *q)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	u8 spi_len = ax_local->ax_spi.comp ? 1 : 4;
+	struct sk_buff *skb, *tx_skb;
+	struct tx_pkt_info *info;
+	struct skb_data *entry;
+	u16 tol_len, pkt_len;
+	u8 padlen, seq_num;
+	u8 need_pages;
+	int headroom;
+	int tailroom;
+
+	if (skb_queue_empty(q))
+		return NULL;
+
+	skb = skb_peek(q);
+	pkt_len = skb->len;
+	need_pages = (pkt_len + TX_OVERHEAD + 127) >> 7;
+	if (ax88796c_check_free_pages(ax_local, need_pages) != 0)
+		return NULL;
+
+	headroom = skb_headroom(skb);
+	tailroom = skb_tailroom(skb);
+	padlen = ((pkt_len + 3) & 0x7FC) - pkt_len;
+	tol_len = ((pkt_len + 3) & 0x7FC) +
+			TX_OVERHEAD + TX_EOP_SIZE + spi_len;
+	seq_num = ++ax_local->seq_num & 0x1F;
+
+	info = (struct tx_pkt_info *)skb->cb;
+	info->pkt_len = pkt_len;
+
+	if ((!skb_cloned(skb)) &&
+	    (headroom >= (TX_OVERHEAD + spi_len)) &&
+	    (tailroom >= (padlen + TX_EOP_SIZE))) {
+		info->seq_num = seq_num;
+		ax88796c_proc_tx_hdr(info, skb->ip_summed);
+
+		/* SOP and SEG header */
+		memcpy(skb_push(skb, TX_OVERHEAD), &info->sop, TX_OVERHEAD);
+
+		/* Write SPI TXQ header */
+		memcpy(skb_push(skb, spi_len), ax88796c_tx_cmd_buf, spi_len);
+
+		/* Make 32-bit alignment */
+		skb_put(skb, padlen);
+
+		/* EOP header */
+		memcpy(skb_put(skb, TX_EOP_SIZE), &info->eop, TX_EOP_SIZE);
+
+		tx_skb = skb;
+		skb_unlink(skb, q);
+	} else {
+		tx_skb = alloc_skb(tol_len, GFP_KERNEL);
+		if (!tx_skb)
+			return NULL;
+
+		/* Write SPI TXQ header */
+		memcpy(skb_put(tx_skb, spi_len), ax88796c_tx_cmd_buf, spi_len);
+
+		info->seq_num = seq_num;
+		ax88796c_proc_tx_hdr(info, skb->ip_summed);
+
+		/* SOP and SEG header */
+		memcpy(skb_put(tx_skb, TX_OVERHEAD),
+		       &info->sop, TX_OVERHEAD);
+
+		/* Packet */
+		memcpy(skb_put(tx_skb, ((pkt_len + 3) & 0xFFFC)),
+		       skb->data, pkt_len);
+
+		/* EOP header */
+		memcpy(skb_put(tx_skb, TX_EOP_SIZE),
+		       &info->eop, TX_EOP_SIZE);
+
+		skb_unlink(skb, q);
+		dev_kfree_skb(skb);
+	}
+
+	entry = (struct skb_data *)tx_skb->cb;
+	memset(entry, 0, sizeof(*entry));
+	entry->len = pkt_len;
+
+	if (netif_msg_pktdata(ax_local)) {
+		char pfx[IFNAMSIZ + 7];
+
+		snprintf(pfx, sizeof(pfx), "%s:     ", ndev->name);
+
+		netdev_info(ndev, "TX packet len %d, total len %d, seq %d\n",
+			    pkt_len, tx_skb->len, seq_num);
+
+		netdev_info(ndev, "  SPI Header:\n");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       tx_skb->data, 4, 0);
+
+		netdev_info(ndev, "  TX SOP:\n");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       tx_skb->data + 4, TX_OVERHEAD, 0);
+
+		netdev_info(ndev, "  TX packet:\n");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       tx_skb->data + 4 + TX_OVERHEAD,
+			       tx_skb->len - TX_EOP_SIZE - 4 - TX_OVERHEAD, 0);
+
+		netdev_info(ndev, "  TX EOP:\n");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       tx_skb->data + tx_skb->len - 4, 4, 0);
+	}
+
+	return tx_skb;
+}
+
+static int ax88796c_hard_xmit(struct ax88796c_device *ax_local)
+{
+	struct sk_buff *tx_skb;
+	struct skb_data *entry;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	tx_skb = ax88796c_tx_fixup(ax_local->ndev, &ax_local->tx_wait_q);
+
+	if (!tx_skb)
+		return 0;
+
+	entry = (struct skb_data *)tx_skb->cb;
+
+	AX_WRITE(&ax_local->ax_spi,
+		 (TSNR_TXB_START | TSNR_PKT_CNT(1)), P0_TSNR);
+
+	axspi_write_txq(&ax_local->ax_spi, tx_skb->data, tx_skb->len);
+
+	if (((AX_READ(&ax_local->ax_spi, P0_TSNR) & TXNR_TXB_IDLE) == 0) ||
+	    ((ISR_TXERR & AX_READ(&ax_local->ax_spi, P0_ISR)) != 0)) {
+		/* Ack tx error int */
+		AX_WRITE(&ax_local->ax_spi, ISR_TXERR, P0_ISR);
+
+		ax_local->stats.tx_dropped++;
+
+		netif_err(ax_local, tx_err, ax_local->ndev,
+			  "TX FIFO error, re-initialize the TX bridge\n");
+
+		/* Reinitial tx bridge */
+		AX_WRITE(&ax_local->ax_spi, TXNR_TXB_REINIT |
+			AX_READ(&ax_local->ax_spi, P0_TSNR), P0_TSNR);
+		ax_local->seq_num = 0;
+	} else {
+		ax_local->stats.tx_packets++;
+		ax_local->stats.tx_bytes += entry->len;
+	}
+
+	entry->state = tx_done;
+	dev_kfree_skb(tx_skb);
+
+	return 1;
+}
+
+static int
+ax88796c_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	skb_queue_tail(&ax_local->tx_wait_q, skb);
+	if (skb_queue_len(&ax_local->tx_wait_q) > TX_QUEUE_HIGH_WATER)
+		netif_stop_queue(ndev);
+
+	set_bit(EVENT_TX, &ax_local->flags);
+	schedule_work(&ax_local->ax_work);
+
+	return NETDEV_TX_OK;
+}
+
+static void
+ax88796c_skb_return(struct ax88796c_device *ax_local, struct sk_buff *skb,
+		    struct rx_header *rxhdr)
+{
+	struct net_device *ndev = ax_local->ndev;
+	int status;
+
+	do {
+		if (!(ndev->features & NETIF_F_RXCSUM))
+			break;
+
+		/* checksum error bit is set */
+		if ((rxhdr->flags & RX_HDR3_L3_ERR) ||
+		    (rxhdr->flags & RX_HDR3_L4_ERR))
+			break;
+
+		/* Other types may be indicated by more than one bit. */
+		if ((rxhdr->flags & RX_HDR3_L4_TYPE_TCP) ||
+		    (rxhdr->flags & RX_HDR3_L4_TYPE_UDP))
+			skb->ip_summed = CHECKSUM_UNNECESSARY;
+	} while (0);
+
+	ax_local->stats.rx_packets++;
+	ax_local->stats.rx_bytes += skb->len;
+	skb->dev = ndev;
+
+	skb->truesize = skb->len + sizeof(struct sk_buff);
+	skb->protocol = eth_type_trans(skb, ax_local->ndev);
+
+	netif_info(ax_local, rx_status, ndev, "< rx, len %zu, type 0x%x\n",
+		   skb->len + sizeof(struct ethhdr), skb->protocol);
+
+	status = netif_rx_ni(skb);
+	if (status != NET_RX_SUCCESS)
+		netif_info(ax_local, rx_err, ndev,
+			   "netif_rx status %d\n", status);
+}
+
+static void
+ax88796c_rx_fixup(struct ax88796c_device *ax_local, struct sk_buff *rx_skb)
+{
+	struct rx_header *rxhdr = (struct rx_header *)rx_skb->data;
+	struct net_device *ndev = ax_local->ndev;
+	u16 len;
+
+	be16_to_cpus(&rxhdr->flags_len);
+	be16_to_cpus(&rxhdr->seq_lenbar);
+	be16_to_cpus(&rxhdr->flags);
+
+	if ((((short)rxhdr->flags_len) & RX_HDR1_PKT_LEN) !=
+			 (~((short)rxhdr->seq_lenbar) & 0x7FF)) {
+		netif_err(ax_local, rx_err, ndev, "Header error\n");
+
+		ax_local->stats.rx_frame_errors++;
+		kfree_skb(rx_skb);
+		return;
+	}
+
+	if ((rxhdr->flags_len & RX_HDR1_MII_ERR) ||
+	    (rxhdr->flags_len & RX_HDR1_CRC_ERR)) {
+		netif_err(ax_local, rx_err, ndev, "CRC or MII error\n");
+
+		ax_local->stats.rx_crc_errors++;
+		kfree_skb(rx_skb);
+		return;
+	}
+
+	len = rxhdr->flags_len & RX_HDR1_PKT_LEN;
+	if (netif_msg_pktdata(ax_local)) {
+		char pfx[IFNAMSIZ + 7];
+
+		snprintf(pfx, sizeof(pfx), "%s:     ", ndev->name);
+		netdev_info(ndev, "RX data, total len %d, packet len %d\n",
+			    rx_skb->len, len);
+
+		netdev_info(ndev, "  Dump RX packet header:");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       rx_skb->data, sizeof(*rxhdr), 0);
+
+		netdev_info(ndev, "  Dump RX packet:");
+		print_hex_dump(KERN_INFO, pfx, DUMP_PREFIX_OFFSET, 16, 1,
+			       rx_skb->data + sizeof(*rxhdr), len, 0);
+	}
+
+	skb_pull(rx_skb, sizeof(*rxhdr));
+	__pskb_trim(rx_skb, len);
+
+	return ax88796c_skb_return(ax_local, rx_skb, rxhdr);
+}
+
+static int ax88796c_receive(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	struct skb_data *entry;
+	u16 w_count, pkt_len;
+	struct sk_buff *skb;
+	u8 pkt_cnt;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	/* check rx packet and total word count */
+	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_RTWCR)
+		  | RTWCR_RX_LATCH, P0_RTWCR);
+
+	pkt_cnt = AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_PKT_MASK;
+	if (!pkt_cnt)
+		return 0;
+
+	pkt_len = AX_READ(&ax_local->ax_spi, P0_RCPHR) & 0x7FF;
+
+	w_count = ((pkt_len + 6 + 3) & 0xFFFC) >> 1;
+
+	skb = alloc_skb((w_count * 2), GFP_ATOMIC);
+	if (!skb) {
+		AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_DISCARD, P0_RXBCR1);
+		return 0;
+	}
+	entry = (struct skb_data *)skb->cb;
+
+	AX_WRITE(&ax_local->ax_spi, RXBCR1_RXB_START | w_count, P0_RXBCR1);
+
+	axspi_read_rxq(&ax_local->ax_spi,
+		       skb_put(skb, w_count * 2), skb->len);
+
+	/* Check if rx bridge is idle */
+	if ((AX_READ(&ax_local->ax_spi, P0_RXBCR2) & RXBCR2_RXB_IDLE) == 0) {
+		netif_err(ax_local, rx_err, ndev,
+			  "Rx Bridge is not idle\n");
+		AX_WRITE(&ax_local->ax_spi, RXBCR2_RXB_REINIT, P0_RXBCR2);
+
+		entry->state = rx_err;
+	} else {
+		entry->state = rx_done;
+	}
+
+	AX_WRITE(&ax_local->ax_spi, ISR_RXPKT, P0_ISR);
+
+	ax88796c_rx_fixup(ax_local, skb);
+
+	return 1;
+}
+
+static int ax88796c_process_isr(struct ax88796c_device *ax_local)
+{
+	struct net_device *ndev = ax_local->ndev;
+	u8 done = 0;
+	u16 isr;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	isr = AX_READ(&ax_local->ax_spi, P0_ISR);
+	AX_WRITE(&ax_local->ax_spi, isr, P0_ISR);
+
+	netif_dbg(ax_local, intr, ndev, "  ISR 0x%04x\n", isr);
+
+	if (isr & ISR_TXERR) {
+		netif_dbg(ax_local, intr, ndev, "  TXERR interrupt\n");
+		AX_WRITE(&ax_local->ax_spi, TXNR_TXB_REINIT, P0_TSNR);
+		ax_local->seq_num = 0x1f;
+	}
+
+	if (isr & ISR_TXPAGES) {
+		netif_dbg(ax_local, intr, ndev, "  TXPAGES interrupt\n");
+		set_bit(EVENT_TX, &ax_local->flags);
+	}
+
+	if (isr & ISR_LINK) {
+		netif_dbg(ax_local, intr, ndev, "  Link change interrupt\n");
+		phy_mac_interrupt(ax_local->ndev->phydev);
+	}
+
+	if (isr & ISR_RXPKT) {
+		netif_dbg(ax_local, intr, ndev, "  RX interrupt\n");
+		done = ax88796c_receive(ax_local->ndev);
+	}
+
+	return done;
+}
+
+static irqreturn_t ax88796c_interrupt(int irq, void *dev_instance)
+{
+	struct ax88796c_device *ax_local;
+	struct net_device *ndev;
+
+	ndev = dev_instance;
+	if (!ndev) {
+		pr_err("irq %d for unknown device.\n", irq);
+		return IRQ_RETVAL(0);
+	}
+	ax_local = to_ax88796c_device(ndev);
+
+	disable_irq_nosync(irq);
+
+	netif_dbg(ax_local, intr, ndev, "Interrupt occurred\n");
+
+	set_bit(EVENT_INTR, &ax_local->flags);
+	schedule_work(&ax_local->ax_work);
+
+	return IRQ_HANDLED;
+}
+
+static void ax88796c_work(struct work_struct *work)
+{
+	struct ax88796c_device *ax_local =
+			container_of(work, struct ax88796c_device, ax_work);
+
+	mutex_lock(&ax_local->spi_lock);
+
+	if (test_bit(EVENT_SET_MULTI, &ax_local->flags)) {
+		ax88796c_set_hw_multicast(ax_local->ndev);
+		clear_bit(EVENT_SET_MULTI, &ax_local->flags);
+	}
+
+	if (test_bit(EVENT_INTR, &ax_local->flags)) {
+		AX_WRITE(&ax_local->ax_spi, IMR_MASKALL, P0_IMR);
+
+		while (1) {
+			if (!ax88796c_process_isr(ax_local))
+				break;
+		}
+
+		clear_bit(EVENT_INTR, &ax_local->flags);
+
+		AX_WRITE(&ax_local->ax_spi, IMR_DEFAULT, P0_IMR);
+
+		enable_irq(ax_local->ndev->irq);
+	}
+
+	if (test_bit(EVENT_TX, &ax_local->flags)) {
+		while (skb_queue_len(&ax_local->tx_wait_q)) {
+			if (!ax88796c_hard_xmit(ax_local))
+				break;
+		}
+
+		clear_bit(EVENT_TX, &ax_local->flags);
+
+		if (netif_queue_stopped(ax_local->ndev) &&
+		    (skb_queue_len(&ax_local->tx_wait_q) < TX_QUEUE_LOW_WATER))
+			netif_wake_queue(ax_local->ndev);
+	}
+
+	mutex_unlock(&ax_local->spi_lock);
+}
+
+static struct net_device_stats *ax88796c_get_stats(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	return &ax_local->stats;
+}
+
+static void ax88796c_set_mac(struct  ax88796c_device *ax_local)
+{
+	u16 maccr;
+
+	maccr = (ax_local->link) ? MACCR_RXEN : 0;
+
+	switch (ax_local->speed) {
+	case SPEED_100:
+		maccr |= MACCR_SPEED_100;
+	case SPEED_10:
+	case SPEED_UNKNOWN:
+		break;
+	default:
+		return;
+	}
+
+	switch (ax_local->duplex) {
+	case DUPLEX_FULL:
+		maccr |= MACCR_SPEED_100;
+	case DUPLEX_HALF:
+	case DUPLEX_UNKNOWN:
+		break;
+	default:
+		return;
+	}
+
+	if (ax_local->flowctrl & AX_FC_ANEG &&
+	    ax_local->phydev->autoneg) {
+		maccr |= ax_local->pause ? MACCR_RXFC_ENABLE : 0;
+		maccr |= !ax_local->pause != !ax_local->asym_pause ?
+			MACCR_TXFC_ENABLE : 0;
+	} else {
+		maccr |= (ax_local->flowctrl & AX_FC_RX) ? MACCR_RXFC_ENABLE : 0;
+		maccr |= (ax_local->flowctrl & AX_FC_TX) ? MACCR_TXFC_ENABLE : 0;
+	}
+
+	mutex_lock(&ax_local->spi_lock);
+
+	maccr |= AX_READ(&ax_local->ax_spi, P0_MACCR) &
+		~(MACCR_DUPLEX_FULL | MACCR_SPEED_100 |
+		  MACCR_TXFC_ENABLE | MACCR_RXFC_ENABLE);
+	AX_WRITE(&ax_local->ax_spi, maccr, P0_MACCR);
+
+	mutex_unlock(&ax_local->spi_lock);
+}
+
+static void ax88796c_handle_link_change(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	struct phy_device *phydev = ndev->phydev;
+	bool update = false;
+
+	if (phydev->link && (ax_local->speed != phydev->speed ||
+			     ax_local->duplex != phydev->duplex ||
+			     ax_local->pause != phydev->pause ||
+			     ax_local->asym_pause != phydev->asym_pause)) {
+		ax_local->speed = phydev->speed;
+		ax_local->duplex = phydev->duplex;
+		ax_local->pause = phydev->pause;
+		ax_local->asym_pause = phydev->asym_pause;
+		update = true;
+	}
+
+	if (phydev->link != ax_local->link) {
+		if (!phydev->link) {
+			ax_local->speed = SPEED_UNKNOWN;
+			ax_local->duplex = DUPLEX_UNKNOWN;
+		}
+
+		ax_local->link = phydev->link;
+		update = true;
+	}
+
+	if (update)
+		ax88796c_set_mac(ax_local);
+
+	if (net_ratelimit())
+		phy_print_status(ndev->phydev);
+}
+
+static void ax88796c_set_csums(struct ax88796c_device *ax_local)
+{
+	struct net_device *ndev = ax_local->ndev;
+
+	WARN_ON(!mutex_is_locked(&ax_local->spi_lock));
+
+	if (ndev->features & NETIF_F_RXCSUM) {
+		AX_WRITE(&ax_local->ax_spi, COERCR0_DEFAULT, P4_COERCR0);
+		AX_WRITE(&ax_local->ax_spi, COERCR1_DEFAULT, P4_COERCR1);
+	} else {
+		AX_WRITE(&ax_local->ax_spi, 0, P4_COERCR0);
+		AX_WRITE(&ax_local->ax_spi, 0, P4_COERCR1);
+	}
+
+	if (ndev->features & NETIF_F_HW_CSUM) {
+		AX_WRITE(&ax_local->ax_spi, COETCR0_DEFAULT, P4_COETCR0);
+		AX_WRITE(&ax_local->ax_spi, COETCR1_TXPPPE, P4_COETCR1);
+	} else {
+		AX_WRITE(&ax_local->ax_spi, 0, P4_COETCR0);
+		AX_WRITE(&ax_local->ax_spi, 0, P4_COETCR1);
+	}
+}
+
+static int
+ax88796c_open(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	unsigned long irq_flag = IRQF_SHARED;
+	int fc = AX_FC_NONE;
+	int ret;
+
+	ret = request_irq(ndev->irq, ax88796c_interrupt,
+			  irq_flag, ndev->name, ndev);
+	if (ret) {
+		netdev_err(ndev, "unable to get IRQ %d (errno=%d).\n",
+			   ndev->irq, ret);
+		return ret;
+	}
+
+	mutex_lock(&ax_local->spi_lock);
+
+	ret = ax88796c_soft_reset(ax_local);
+	if (ret < 0) {
+		mutex_unlock(&ax_local->spi_lock);
+		return ret;
+	}
+	ax_local->seq_num = 0x1f;
+
+	ax88796c_set_mac_addr(ndev);
+	ax88796c_set_csums(ax_local);
+
+	/* Disable stuffing packet */
+	AX_WRITE(&ax_local->ax_spi,
+		 AX_READ(&ax_local->ax_spi, P1_RXBSPCR)
+		 & ~RXBSPCR_STUF_ENABLE, P1_RXBSPCR);
+
+	/* Enable RX packet process */
+	AX_WRITE(&ax_local->ax_spi, RPPER_RXEN, P1_RPPER);
+
+	AX_WRITE(&ax_local->ax_spi, AX_READ(&ax_local->ax_spi, P0_FER)
+		 | FER_RXEN | FER_TXEN | FER_BSWAP | FER_IRQ_PULL, P0_FER);
+
+	/* Setup LED mode */
+	AX_WRITE(&ax_local->ax_spi,
+		 (LCR_LED0_EN | LCR_LED0_DUPLEX | LCR_LED1_EN |
+		 LCR_LED1_100MODE), P2_LCR0);
+	AX_WRITE(&ax_local->ax_spi,
+		 (AX_READ(&ax_local->ax_spi, P2_LCR1) & LCR_LED2_MASK) |
+		 LCR_LED2_EN | LCR_LED2_LINK, P2_LCR1);
+
+	/* Disable PHY auto-polling */
+	AX_WRITE(&ax_local->ax_spi, PCR_PHYID(AX88796C_PHY_ID), P2_PCR);
+
+	/* Enable MAC interrupts */
+	AX_WRITE(&ax_local->ax_spi, IMR_DEFAULT, P0_IMR);
+
+	mutex_unlock(&ax_local->spi_lock);
+
+	/* Setup flow-control configuration */
+	phy_support_asym_pause(ax_local->phydev);
+
+	if (ax_local->phydev->advertising &&
+	    (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
+			       ax_local->phydev->advertising) ||
+	     linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
+			       ax_local->phydev->advertising)))
+		fc |= AX_FC_ANEG;
+
+	fc |= linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
+				ax_local->phydev->advertising) ? AX_FC_RX : 0;
+	fc |= (linkmode_test_bit(ETHTOOL_LINK_MODE_Pause_BIT,
+				 ax_local->phydev->advertising) !=
+	       linkmode_test_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
+				 ax_local->phydev->advertising)) ? AX_FC_TX : 0;
+	ax_local->flowctrl = fc;
+
+	phy_start(ax_local->ndev->phydev);
+
+	netif_start_queue(ndev);
+
+	spi_message_init(&ax_local->ax_spi.rx_msg);
+
+	return 0;
+}
+
+static void ax88796c_free_skb_queue(struct sk_buff_head *q)
+{
+	struct sk_buff *skb;
+
+	while (q->qlen) {
+		skb = skb_dequeue(q);
+		kfree_skb(skb);
+	}
+}
+
+static int
+ax88796c_close(struct net_device *ndev)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+
+	netif_stop_queue(ndev);
+	phy_stop(ndev->phydev);
+
+	mutex_lock(&ax_local->spi_lock);
+
+	/* Disable MAC interrupts */
+	AX_WRITE(&ax_local->ax_spi, IMR_MASKALL, P0_IMR);
+	ax88796c_free_skb_queue(&ax_local->tx_wait_q);
+	ax88796c_soft_reset(ax_local);
+
+	mutex_unlock(&ax_local->spi_lock);
+
+	free_irq(ndev->irq, ndev);
+
+	return 0;
+}
+
+static int
+ax88796c_set_features(struct net_device *ndev, netdev_features_t features)
+{
+	struct ax88796c_device *ax_local = to_ax88796c_device(ndev);
+	netdev_features_t changed = features ^ ndev->features;
+
+	if (!(changed & (NETIF_F_RXCSUM | NETIF_F_HW_CSUM)))
+		return 0;
+
+	ndev->features = features;
+
+	if (changed & (NETIF_F_RXCSUM | NETIF_F_HW_CSUM))
+		ax88796c_set_csums(ax_local);
+
+	return 0;
+}
+
+static const struct net_device_ops ax88796c_netdev_ops = {
+	.ndo_open		= ax88796c_open,
+	.ndo_stop		= ax88796c_close,
+	.ndo_start_xmit		= ax88796c_start_xmit,
+	.ndo_get_stats		= ax88796c_get_stats,
+	.ndo_do_ioctl		= ax88796c_ioctl,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_set_features	= ax88796c_set_features,
+};
+
+static int ax88796c_hard_reset(struct ax88796c_device *ax_local)
+{
+	struct device *dev = (struct device *)&ax_local->spi->dev;
+	struct gpio_desc *reset_gpio;
+
+	/* reset info */
+	reset_gpio = gpiod_get(dev, "reset", 0);
+	if (IS_ERR(reset_gpio)) {
+		dev_err(dev, "Could not get 'reset' GPIO: %ld", PTR_ERR(reset_gpio));
+		return PTR_ERR(reset_gpio);
+	}
+
+	/* set reset */
+	gpiod_direction_output(reset_gpio, 1);
+	msleep(100);
+	gpiod_direction_output(reset_gpio, 0);
+	gpiod_put(reset_gpio);
+	msleep(20);
+
+	return 0;
+}
+
+static int ax88796c_probe(struct spi_device *spi)
+{
+	char phy_id[MII_BUS_ID_SIZE + 3];
+	struct ax88796c_device *ax_local;
+	struct net_device *ndev;
+	u16 temp;
+	int ret;
+
+	ndev = devm_alloc_etherdev(&spi->dev, sizeof(*ax_local));
+	if (!ndev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(ndev, &spi->dev);
+
+	ax_local = to_ax88796c_device(ndev);
+	memset(ax_local, 0, sizeof(*ax_local));
+
+	dev_set_drvdata(&spi->dev, ax_local);
+	ax_local->spi = spi;
+	ax_local->ax_spi.spi = spi;
+
+	ax_local->ndev = ndev;
+	ax_local->capabilities |= comp ? AX_CAP_COMP : 0;
+	ax_local->msg_enable = msg_enable;
+	mutex_init(&ax_local->spi_lock);
+
+	ax_local->mdiobus = devm_mdiobus_alloc(&spi->dev);
+	if (!ax_local->mdiobus)
+		return -ENOMEM;
+
+	ax_local->mdiobus->priv = ax_local;
+	ax_local->mdiobus->read = ax88796c_mdio_read;
+	ax_local->mdiobus->write = ax88796c_mdio_write;
+	ax_local->mdiobus->name = "ax88976c-mdiobus";
+	ax_local->mdiobus->phy_mask = (u32)~BIT(AX88796C_PHY_ID);
+	ax_local->mdiobus->parent = &spi->dev;
+
+	snprintf(ax_local->mdiobus->id, MII_BUS_ID_SIZE,
+		 "ax88796c-%s.%u", dev_name(&spi->dev), spi->chip_select);
+
+	ret = devm_mdiobus_register(&spi->dev, ax_local->mdiobus);
+	if (ret < 0) {
+		dev_err(&spi->dev, "Could not register MDIO bus\n");
+		return ret;
+	}
+
+	if (netif_msg_probe(ax_local)) {
+		dev_info(&spi->dev, "AX88796C-SPI Configuration:\n");
+		dev_info(&spi->dev, "    Compression : %s\n",
+			 ax_local->capabilities & AX_CAP_COMP ? "ON" : "OFF");
+	}
+
+	ndev->irq = spi->irq;
+	ndev->netdev_ops = &ax88796c_netdev_ops;
+	ndev->ethtool_ops = &ax88796c_ethtool_ops;
+	ndev->hw_features |= NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
+	ndev->features |= NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
+	ndev->hard_header_len += (TX_OVERHEAD + 4);
+
+	mutex_lock(&ax_local->spi_lock);
+
+	/* ax88796c gpio reset */
+	ax88796c_hard_reset(ax_local);
+
+	/* Reset AX88796C */
+	ret = ax88796c_soft_reset(ax_local);
+	if (ret < 0) {
+		ret = -ENODEV;
+		goto err;
+	}
+	/* Check board revision */
+	temp = AX_READ(&ax_local->ax_spi, P2_CRIR);
+	if ((temp & 0xF) != 0x0) {
+		dev_err(&spi->dev, "spi read failed: %d\n", temp);
+		ret = -ENODEV;
+		goto err;
+	}
+
+	temp = AX_READ(&ax_local->ax_spi, P0_BOR);
+	if (temp == 0x1234) {
+		ax_local->plat_endian = PLAT_LITTLE_ENDIAN;
+	} else {
+		AX_WRITE(&ax_local->ax_spi, 0xFFFF, P0_BOR);
+		ax_local->plat_endian = PLAT_BIG_ENDIAN;
+	}
+
+	/*Reload EEPROM*/
+	ax88796c_reload_eeprom(ax_local);
+
+	ax88796c_load_mac_addr(ndev);
+
+	if (netif_msg_probe(ax_local))
+		dev_info(&spi->dev,
+			 "irq %d, MAC addr %02X:%02X:%02X:%02X:%02X:%02X\n",
+			 ndev->irq,
+			 ndev->dev_addr[0], ndev->dev_addr[1],
+			 ndev->dev_addr[2], ndev->dev_addr[3],
+			 ndev->dev_addr[4], ndev->dev_addr[5]);
+
+	/* Disable power saving */
+	AX_WRITE(&ax_local->ax_spi, (AX_READ(&ax_local->ax_spi, P0_PSCR)
+				     & PSCR_PS_MASK) | PSCR_PS_D0, P0_PSCR);
+
+	mutex_unlock(&ax_local->spi_lock);
+
+	INIT_WORK(&ax_local->ax_work, ax88796c_work);
+
+	skb_queue_head_init(&ax_local->tx_wait_q);
+
+	snprintf(phy_id, MII_BUS_ID_SIZE + 3, PHY_ID_FMT,
+		 ax_local->mdiobus->id, AX88796C_PHY_ID);
+	ax_local->phydev = phy_connect(ax_local->ndev, phy_id,
+				       ax88796c_handle_link_change,
+				       PHY_INTERFACE_MODE_MII);
+	if (IS_ERR(ax_local->phydev)) {
+		ret = PTR_ERR(ax_local->phydev);
+		goto err;
+	}
+	ax_local->phydev->irq = PHY_POLL;
+
+	ret = devm_register_netdev(&spi->dev, ndev);
+	if (ret) {
+		dev_err(&spi->dev, "failed to register a network device\n");
+		goto err_phy_dis;
+	}
+
+	netif_info(ax_local, probe, ndev, "%s %s registered\n",
+		   dev_driver_string(&spi->dev),
+		   dev_name(&spi->dev));
+	phy_attached_info(ax_local->phydev);
+
+	return 0;
+
+err_phy_dis:
+	phy_disconnect(ax_local->phydev);
+err:
+	return ret;
+}
+
+static int ax88796c_remove(struct spi_device *spi)
+{
+	struct ax88796c_device *ax_local = dev_get_drvdata(&spi->dev);
+	struct net_device *ndev = ax_local->ndev;
+
+	phy_disconnect(ndev->phydev);
+
+	netif_info(ax_local, probe, ndev, "removing network device %s %s\n",
+		   dev_driver_string(&spi->dev),
+		   dev_name(&spi->dev));
+
+	return 0;
+}
+
+static const struct of_device_id ax88796c_dt_ids[] = {
+	{ .compatible = "asix,ax88796c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ax88796c_dt_ids);
+
+static const struct spi_device_id asix_id[] = {
+	{ "ax88796c", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, asix_id);
+
+static struct spi_driver ax88796c_spi_driver = {
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = of_match_ptr(ax88796c_dt_ids),
+	},
+	.probe = ax88796c_probe,
+	.remove = ax88796c_remove,
+	.id_table = asix_id,
+};
+
+static __init int ax88796c_spi_init(void)
+{
+	int ret;
+
+	bitmap_zero(ax88796c_no_regs_mask, AX88796C_REGDUMP_LEN);
+	ret = bitmap_parse(no_regs_list, 35,
+			   ax88796c_no_regs_mask, AX88796C_REGDUMP_LEN);
+	if (ret) {
+		bitmap_fill(ax88796c_no_regs_mask, AX88796C_REGDUMP_LEN);
+		pr_err("Invalid bitmap description, masking all registers\n");
+	}
+
+	return spi_register_driver(&ax88796c_spi_driver);
+}
+
+static __exit void ax88796c_spi_exit(void)
+{
+	spi_unregister_driver(&ax88796c_spi_driver);
+}
+
+module_init(ax88796c_spi_init);
+module_exit(ax88796c_spi_exit);
+
+MODULE_AUTHOR("ASIX");
+MODULE_DESCRIPTION("ASIX AX88796C SPI Ethernet driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/asix/ax88796c_main.h b/drivers/net/ethernet/asix/ax88796c_main.h
new file mode 100644
index 000000000000..229906d5737f
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_main.h
@@ -0,0 +1,561 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#ifndef _AX88796C_MAIN_H
+#define _AX88796C_MAIN_H
+
+#include <linux/netdevice.h>
+#include <linux/mii.h>
+
+#include "ax88796c_spi.h"
+
+/* These identify the driver base version and may not be removed. */
+#define DRV_NAME	"ax88796c"
+#define ADP_NAME	"ASIX AX88796C SPI Ethernet Adapter"
+
+#define TX_QUEUE_HIGH_WATER		45	/* Tx queue high water mark */
+#define TX_QUEUE_LOW_WATER		20	/* Tx queue low water mark */
+
+#define AX88796C_REGDUMP_LEN		256
+#define AX88796C_PHY_REGDUMP_LEN	14
+#define AX88796C_PHY_ID			0x10
+
+#define TX_OVERHEAD			8
+#define TX_EOP_SIZE			4
+
+#define AX_MCAST_FILTER_SIZE		8
+#define AX_MAX_MCAST			64
+#define AX_MAX_CLK                      80000000
+#define TX_HDR_SOP_DICF			0x8000
+#define TX_HDR_SOP_CPHI			0x4000
+#define TX_HDR_SOP_INT			0x2000
+#define TX_HDR_SOP_MDEQ			0x1000
+#define TX_HDR_SOP_PKTLEN		0x07FF
+#define TX_HDR_SOP_SEQNUM		0xF800
+#define TX_HDR_SOP_PKTLENBAR		0x07FF
+
+#define TX_HDR_SEG_FS			0x8000
+#define TX_HDR_SEG_LS			0x4000
+#define TX_HDR_SEG_SEGNUM		0x3800
+#define TX_HDR_SEG_SEGLEN		0x0700
+#define TX_HDR_SEG_EOFST		0xC000
+#define TX_HDR_SEG_SOFST		0x3800
+#define TX_HDR_SEG_SEGLENBAR		0x07FF
+
+#define TX_HDR_EOP_SEQNUM		0xF800
+#define TX_HDR_EOP_PKTLEN		0x07FF
+#define TX_HDR_EOP_SEQNUMBAR		0xF800
+#define TX_HDR_EOP_PKTLENBAR		0x07FF
+
+/* Rx header fields mask */
+#define RX_HDR1_MCBC			0x8000
+#define RX_HDR1_STUFF_PKT		0x4000
+#define RX_HDR1_MII_ERR			0x2000
+#define RX_HDR1_CRC_ERR			0x1000
+#define RX_HDR1_PKT_LEN			0x07FF
+
+#define RX_HDR2_SEQ_NUM			0xF800
+#define RX_HDR2_PKT_LEN_BAR		0x7FFF
+
+#define RX_HDR3_PE			0x8000
+#define RX_HDR3_L3_TYPE_IPV4V6		0x6000
+#define RX_HDR3_L3_TYPE_IP		0x4000
+#define RX_HDR3_L3_TYPE_IPV6		0x2000
+#define RX_HDR3_L4_TYPE_ICMPV6		0x1400
+#define RX_HDR3_L4_TYPE_TCP		0x1000
+#define RX_HDR3_L4_TYPE_IGMP		0x0c00
+#define RX_HDR3_L4_TYPE_ICMP		0x0800
+#define RX_HDR3_L4_TYPE_UDP		0x0400
+#define RX_HDR3_L3_ERR			0x0200
+#define RX_HDR3_L4_ERR			0x0100
+#define RX_HDR3_PRIORITY(x)		((x) << 4)
+#define RX_HDR3_STRIP			0x0008
+#define RX_HDR3_VLAN_ID			0x0007
+
+struct ax88796c_device {
+	struct spi_device	*spi;
+	struct net_device	*ndev;
+	struct net_device_stats	stats;
+
+	struct work_struct	ax_work;
+
+	struct mutex		spi_lock; /* device access */
+
+	struct sk_buff_head	tx_wait_q;
+
+	struct axspi_data	ax_spi;
+
+	struct mii_bus		*mdiobus;
+	struct phy_device	*phydev;
+
+	int			msg_enable;
+
+	u16			seq_num;
+
+	u8			multi_filter[AX_MCAST_FILTER_SIZE];
+
+	int			link;
+	int			speed;
+	int			duplex;
+	int			pause;
+	int			asym_pause;
+	int			flowctrl;
+		#define AX_FC_NONE		0
+		#define AX_FC_RX		BIT(0)
+		#define AX_FC_TX		BIT(1)
+		#define AX_FC_ANEG		BIT(2)
+
+	unsigned long		capabilities;
+		#define AX_CAP_COMP		BIT(0)
+
+	u8			plat_endian;
+		#define PLAT_LITTLE_ENDIAN	0
+		#define PLAT_BIG_ENDIAN		1
+
+	unsigned long		flags;
+		#define EVENT_INTR		BIT(0)
+		#define EVENT_TX		BIT(1)
+		#define EVENT_SET_MULTI		BIT(2)
+
+};
+
+#define to_ax88796c_device(ndev) ((struct ax88796c_device *)netdev_priv(ndev))
+
+enum skb_state {
+	illegal = 0,
+	tx_done,
+	rx_done,
+	rx_err,
+};
+
+struct skb_data {
+	enum skb_state state;
+	struct net_device *ndev;
+	struct sk_buff *skb;
+	size_t len;
+};
+
+/* A88796C register definition */
+	/* Definition of PAGE0 */
+#define P0_PSR		(0x00)
+	#define PSR_DEV_READY		BIT(7)
+	#define PSR_RESET		(0 << 15)
+	#define PSR_RESET_CLR		BIT(15)
+#define P0_BOR		(0x02)
+#define P0_FER		(0x04)
+	#define FER_IPALM		BIT(0)
+	#define FER_DCRC		BIT(1)
+	#define FER_RH3M		BIT(2)
+	#define FER_HEADERSWAP		BIT(7)
+	#define FER_WSWAP		BIT(8)
+	#define FER_BSWAP		BIT(9)
+	#define FER_INTHI		BIT(10)
+	#define FER_INTLO		(0 << 10)
+	#define FER_IRQ_PULL		BIT(11)
+	#define FER_RXEN		BIT(14)
+	#define FER_TXEN		BIT(15)
+#define P0_ISR		(0x06)
+	#define ISR_RXPKT		BIT(0)
+	#define ISR_MDQ			BIT(4)
+	#define ISR_TXT			BIT(5)
+	#define ISR_TXPAGES		BIT(6)
+	#define ISR_TXERR		BIT(8)
+	#define ISR_LINK		BIT(9)
+#define P0_IMR		(0x08)
+	#define IMR_RXPKT		BIT(0)
+	#define IMR_MDQ			BIT(4)
+	#define IMR_TXT			BIT(5)
+	#define IMR_TXPAGES		BIT(6)
+	#define IMR_TXERR		BIT(8)
+	#define IMR_LINK		BIT(9)
+	#define IMR_MASKALL		(0xFFFF)
+	#define IMR_DEFAULT		(IMR_TXERR)
+#define P0_WFCR		(0x0A)
+	#define WFCR_PMEIND		BIT(0) /* PME indication */
+	#define WFCR_PMETYPE		BIT(1) /* PME I/O type */
+	#define WFCR_PMEPOL		BIT(2) /* PME polarity */
+	#define WFCR_PMERST		BIT(3) /* Reset PME */
+	#define WFCR_SLEEP		BIT(4) /* Enable sleep mode */
+	#define WFCR_WAKEUP		BIT(5) /* Enable wakeup mode */
+	#define WFCR_WAITEVENT		BIT(6) /* Reserved */
+	#define WFCR_CLRWAKE		BIT(7) /* Clear wakeup */
+	#define WFCR_LINKCH		BIT(8) /* Enable link change */
+	#define WFCR_MAGICP		BIT(9) /* Enable magic packet */
+	#define WFCR_WAKEF		BIT(10) /* Enable wakeup frame */
+	#define WFCR_PMEEN		BIT(11) /* Enable PME pin */
+	#define WFCR_LINKCHS		BIT(12) /* Link change status */
+	#define WFCR_MAGICPS		BIT(13) /* Magic packet status */
+	#define WFCR_WAKEFS		BIT(14) /* Wakeup frame status */
+	#define WFCR_PMES		BIT(15) /* PME pin status */
+#define P0_PSCR		(0x0C)
+	#define PSCR_PS_MASK		(0xFFF0)
+	#define PSCR_PS_D0		(0)
+	#define PSCR_PS_D1		BIT(0)
+	#define PSCR_PS_D2		BIT(1)
+	#define PSCR_FPS		BIT(3) /* Enable fiber mode PS */
+	#define PSCR_SWPS		BIT(4) /* Enable software */
+						 /* PS control */
+	#define PSCR_WOLPS		BIT(5) /* Enable WOL PS */
+	#define PSCR_SWWOL		BIT(6) /* Enable software select */
+						 /* WOL PS */
+	#define PSCR_PHYOSC		BIT(7) /* Internal PHY OSC control */
+	#define PSCR_FOFEF		BIT(8) /* Force PHY generate FEF */
+	#define PSCR_FOF		BIT(9) /* Force PHY in fiber mode */
+	#define PSCR_PHYPD		BIT(10) /* PHY power down. */
+						  /* Active high */
+	#define PSCR_PHYRST		BIT(11) /* PHY reset signal. */
+						  /* Active low */
+	#define PSCR_PHYCSIL		BIT(12) /* PHY cable energy detect */
+	#define PSCR_PHYCOFF		BIT(13) /* PHY cable off */
+	#define PSCR_PHYLINK		BIT(14) /* PHY link status */
+	#define PSCR_EEPOK		BIT(15) /* EEPROM load complete */
+#define P0_MACCR	(0x0E)
+	#define MACCR_RXEN		BIT(0) /* Enable RX */
+	#define MACCR_DUPLEX_FULL	BIT(1) /* 1: Full, 0: Half */
+	#define MACCR_SPEED_100		BIT(2) /* 1: 100Mbps, 0: 10Mbps */
+	#define MACCR_RXFC_ENABLE	BIT(3)
+	#define MACCR_RXFC_MASK		0xFFF7
+	#define MACCR_TXFC_ENABLE	BIT(4)
+	#define MACCR_TXFC_MASK		0xFFEF
+	#define MACCR_PSI		BIT(6) /* Software Cable-Off */
+					       /* Power Saving Interrupt */
+	#define MACCR_PF		BIT(7)
+	#define MACCR_PMM_BITS		8
+	#define MACCR_PMM_MASK		(0x1F00)
+	#define MACCR_PMM_RESET		BIT(8)
+	#define MACCR_PMM_WAIT		(2 << 8)
+	#define MACCR_PMM_READY		(3 << 8)
+	#define MACCR_PMM_D1		(4 << 8)
+	#define MACCR_PMM_D2		(5 << 8)
+	#define MACCR_PMM_WAKE		(7 << 8)
+	#define MACCR_PMM_D1_WAKE	(8 << 8)
+	#define MACCR_PMM_D2_WAKE	(9 << 8)
+	#define MACCR_PMM_SLEEP		(10 << 8)
+	#define MACCR_PMM_PHY_RESET	(11 << 8)
+	#define MACCR_PMM_SOFT_D1	(16 << 8)
+	#define MACCR_PMM_SOFT_D2	(17 << 8)
+#define P0_TFBFCR	(0x10)
+	#define TFBFCR_SCHE_FREE_PAGE	0xE07F
+	#define TFBFCR_FREE_PAGE_BITS	0x07
+	#define TFBFCR_FREE_PAGE_LATCH	BIT(6)
+	#define TFBFCR_SET_FREE_PAGE(x)	(((x) & 0x3F) << TFBFCR_FREE_PAGE_BITS)
+	#define TFBFCR_TX_PAGE_SET	BIT(13)
+	#define TFBFCR_MANU_ENTX	BIT(15)
+	#define TX_FREEBUF_MASK		0x003F
+	#define TX_DPTSTART		0x4000
+
+#define P0_TSNR		(0x12)
+	#define TXNR_TXB_ERR		BIT(5)
+	#define TXNR_TXB_IDLE		BIT(6)
+	#define TSNR_PKT_CNT(x)		(((x) & 0x3F) << 8)
+	#define TXNR_TXB_REINIT		BIT(14)
+	#define TSNR_TXB_START		BIT(15)
+#define P0_RTDPR	(0x14)
+#define P0_RXBCR1	(0x16)
+	#define RXBCR1_RXB_DISCARD	BIT(14)
+	#define RXBCR1_RXB_START	BIT(15)
+#define P0_RXBCR2	(0x18)
+	#define RXBCR2_PKT_MASK		(0xFF)
+	#define RXBCR2_RXPC_MASK	(0x7F)
+	#define RXBCR2_RXB_READY	BIT(13)
+	#define RXBCR2_RXB_IDLE		BIT(14)
+	#define RXBCR2_RXB_REINIT	BIT(15)
+#define P0_RTWCR	(0x1A)
+	#define RTWCR_RXWC_MASK		(0x3FFF)
+	#define RTWCR_RX_LATCH		BIT(15)
+#define P0_RCPHR	(0x1C)
+
+	/* Definition of PAGE1 */
+#define P1_RPPER	(0x22)
+	#define RPPER_RXEN		BIT(0)
+#define P1_MRCR		(0x28)
+#define P1_MDR		(0x2A)
+#define P1_RMPR		(0x2C)
+#define P1_TMPR		(0x2E)
+#define P1_RXBSPCR	(0x30)
+	#define RXBSPCR_STUF_WORD_CNT(x)	(((x) & 0x7000) >> 12)
+	#define RXBSPCR_STUF_ENABLE		BIT(15)
+#define P1_MCR		(0x32)
+	#define MCR_SBP			BIT(8)
+	#define MCR_SM			BIT(9)
+	#define MCR_CRCENLAN		BIT(11)
+	#define MCR_STP			BIT(12)
+	/* Definition of PAGE2 */
+#define P2_CIR		(0x42)
+#define P2_PCR		(0x44)
+	#define PCR_POLL_EN		BIT(0)
+	#define PCR_POLL_FLOWCTRL	BIT(1)
+	#define PCR_POLL_BMCR		BIT(2)
+	#define PCR_PHYID(x)		((x) << 8)
+#define P2_PHYSR	(0x46)
+#define P2_MDIODR	(0x48)
+#define P2_MDIOCR	(0x4A)
+	#define MDIOCR_RADDR(x)		((x) & 0x1F)
+	#define MDIOCR_FADDR(x)		(((x) & 0x1F) << 8)
+	#define MDIOCR_VALID		BIT(13)
+	#define MDIOCR_READ		BIT(14)
+	#define MDIOCR_WRITE		BIT(15)
+#define P2_LCR0		(0x4C)
+	#define LCR_LED0_EN		BIT(0)
+	#define LCR_LED0_100MODE	BIT(1)
+	#define LCR_LED0_DUPLEX		BIT(2)
+	#define LCR_LED0_LINK		BIT(3)
+	#define LCR_LED0_ACT		BIT(4)
+	#define LCR_LED0_COL		BIT(5)
+	#define LCR_LED0_10MODE		BIT(6)
+	#define LCR_LED0_DUPCOL		BIT(7)
+	#define LCR_LED1_EN		BIT(8)
+	#define LCR_LED1_100MODE	BIT(9)
+	#define LCR_LED1_DUPLEX		BIT(10)
+	#define LCR_LED1_LINK		BIT(11)
+	#define LCR_LED1_ACT		BIT(12)
+	#define LCR_LED1_COL		BIT(13)
+	#define LCR_LED1_10MODE		BIT(14)
+	#define LCR_LED1_DUPCOL		BIT(15)
+#define P2_LCR1		(0x4E)
+	#define LCR_LED2_MASK		(0xFF00)
+	#define LCR_LED2_EN		BIT(0)
+	#define LCR_LED2_100MODE	BIT(1)
+	#define LCR_LED2_DUPLEX		BIT(2)
+	#define LCR_LED2_LINK		BIT(3)
+	#define LCR_LED2_ACT		BIT(4)
+	#define LCR_LED2_COL		BIT(5)
+	#define LCR_LED2_10MODE		BIT(6)
+	#define LCR_LED2_DUPCOL		BIT(7)
+#define P2_IPGCR	(0x50)
+#define P2_CRIR		(0x52)
+#define P2_FLHWCR	(0x54)
+#define P2_RXCR		(0x56)
+	#define RXCR_PRO		BIT(0)
+	#define RXCR_AMALL		BIT(1)
+	#define RXCR_SEP		BIT(2)
+	#define RXCR_AB			BIT(3)
+	#define RXCR_AM			BIT(4)
+	#define RXCR_AP			BIT(5)
+	#define RXCR_ARP		BIT(6)
+#define P2_JLCR		(0x58)
+#define P2_MPLR		(0x5C)
+
+	/* Definition of PAGE3 */
+#define P3_MACASR0	(0x62)
+	#define P3_MACASR(x)		(P3_MACASR0 + 2 * (x))
+	#define MACASR_LOWBYTE_MASK	0x00FF
+	#define MACASR_HIGH_BITS	0x08
+#define P3_MACASR1	(0x64)
+#define P3_MACASR2	(0x66)
+#define P3_MFAR01	(0x68)
+#define P3_MFAR_BASE	(0x68)
+	#define P3_MFAR(x)		(P3_MFAR_BASE + 2 * (x))
+
+#define P3_MFAR23	(0x6A)
+#define P3_MFAR45	(0x6C)
+#define P3_MFAR67	(0x6E)
+#define P3_VID0FR	(0x70)
+#define P3_VID1FR	(0x72)
+#define P3_EECSR	(0x74)
+#define P3_EEDR		(0x76)
+#define P3_EECR		(0x78)
+	#define EECR_ADDR_MASK		(0x00FF)
+	#define EECR_READ_ACT		BIT(8)
+	#define EECR_WRITE_ACT		BIT(9)
+	#define EECR_WRITE_DISABLE	BIT(10)
+	#define EECR_WRITE_ENABLE	BIT(11)
+	#define EECR_EE_READY		BIT(13)
+	#define EECR_RELOAD		BIT(14)
+	#define EECR_RESET		BIT(15)
+#define P3_TPCR		(0x7A)
+	#define TPCR_PATT_MASK		(0xFF)
+	#define TPCR_RAND_PKT_EN	BIT(14)
+	#define TPCR_FIXED_PKT_EN	BIT(15)
+#define P3_TPLR		(0x7C)
+	/* Definition of PAGE4 */
+#define P4_SPICR	(0x8A)
+	#define SPICR_RCEN		BIT(0)
+	#define SPICR_QCEN		BIT(1)
+	#define SPICR_RBRE		BIT(3)
+	#define SPICR_PMM		BIT(4)
+	#define SPICR_LOOPBACK		BIT(8)
+	#define SPICR_CORE_RES_CLR	BIT(10)
+	#define SPICR_SPI_RES_CLR	BIT(11)
+#define P4_SPIISMR	(0x8C)
+
+#define P4_COERCR0	(0x92)
+	#define COERCR0_RXIPCE		BIT(0)
+	#define COERCR0_RXIPVE		BIT(1)
+	#define COERCR0_RXV6PE		BIT(2)
+	#define COERCR0_RXTCPE		BIT(3)
+	#define COERCR0_RXUDPE		BIT(4)
+	#define COERCR0_RXICMP		BIT(5)
+	#define COERCR0_RXIGMP		BIT(6)
+	#define COERCR0_RXICV6		BIT(7)
+
+	#define COERCR0_RXTCPV6		BIT(8)
+	#define COERCR0_RXUDPV6		BIT(9)
+	#define COERCR0_RXICMV6		BIT(10)
+	#define COERCR0_RXIGMV6		BIT(11)
+	#define COERCR0_RXICV6V6	BIT(12)
+
+	#define COERCR0_DEFAULT		(COERCR0_RXIPCE | COERCR0_RXV6PE | \
+					 COERCR0_RXTCPE | COERCR0_RXUDPE | \
+					 COERCR0_RXTCPV6 | COERCR0_RXUDPV6)
+#define P4_COERCR1	(0x94)
+	#define COERCR1_IPCEDP		BIT(0)
+	#define COERCR1_IPVEDP		BIT(1)
+	#define COERCR1_V6VEDP		BIT(2)
+	#define COERCR1_TCPEDP		BIT(3)
+	#define COERCR1_UDPEDP		BIT(4)
+	#define COERCR1_ICMPDP		BIT(5)
+	#define COERCR1_IGMPDP		BIT(6)
+	#define COERCR1_ICV6DP		BIT(7)
+	#define COERCR1_RX64TE		BIT(8)
+	#define COERCR1_RXPPPE		BIT(9)
+	#define COERCR1_TCP6DP		BIT(10)
+	#define COERCR1_UDP6DP		BIT(11)
+	#define COERCR1_IC6DP		BIT(12)
+	#define COERCR1_IG6DP		BIT(13)
+	#define COERCR1_ICV66DP		BIT(14)
+	#define COERCR1_RPCE		BIT(15)
+
+	#define COERCR1_DEFAULT		(COERCR1_RXPPPE)
+
+#define P4_COETCR0	(0x96)
+	#define COETCR0_TXIP		BIT(0)
+	#define COETCR0_TXTCP		BIT(1)
+	#define COETCR0_TXUDP		BIT(2)
+	#define COETCR0_TXICMP		BIT(3)
+	#define COETCR0_TXIGMP		BIT(4)
+	#define COETCR0_TXICV6		BIT(5)
+	#define COETCR0_TXTCPV6		BIT(8)
+	#define COETCR0_TXUDPV6		BIT(9)
+	#define COETCR0_TXICMV6		BIT(10)
+	#define COETCR0_TXIGMV6		BIT(11)
+	#define COETCR0_TXICV6V6	BIT(12)
+
+	#define COETCR0_DEFAULT		(COETCR0_TXIP | COETCR0_TXTCP | \
+					 COETCR0_TXUDP | COETCR0_TXTCPV6 | \
+					 COETCR0_TXUDPV6)
+#define P4_COETCR1	(0x98)
+	#define COETCR1_TX64TE		BIT(0)
+	#define COETCR1_TXPPPE		BIT(1)
+
+#define P4_COECEDR	(0x9A)
+#define P4_L2CECR	(0x9C)
+
+	/* Definition of PAGE5 */
+#define P5_WFTR		(0xA2)
+	#define WFTR_2MS		(0x01)
+	#define WFTR_4MS		(0x02)
+	#define WFTR_8MS		(0x03)
+	#define WFTR_16MS		(0x04)
+	#define WFTR_32MS		(0x05)
+	#define WFTR_64MS		(0x06)
+	#define WFTR_128MS		(0x07)
+	#define WFTR_256MS		(0x08)
+	#define WFTR_512MS		(0x09)
+	#define WFTR_1024MS		(0x0A)
+	#define WFTR_2048MS		(0x0B)
+	#define WFTR_4096MS		(0x0C)
+	#define WFTR_8192MS		(0x0D)
+	#define WFTR_16384MS		(0x0E)
+	#define WFTR_32768MS		(0x0F)
+#define P5_WFCCR	(0xA4)
+#define P5_WFCR03	(0xA6)
+	#define WFCR03_F0_EN		BIT(0)
+	#define WFCR03_F1_EN		BIT(4)
+	#define WFCR03_F2_EN		BIT(8)
+	#define WFCR03_F3_EN		BIT(12)
+#define P5_WFCR47	(0xA8)
+	#define WFCR47_F4_EN		BIT(0)
+	#define WFCR47_F5_EN		BIT(4)
+	#define WFCR47_F6_EN		BIT(8)
+	#define WFCR47_F7_EN		BIT(12)
+#define P5_WF0BMR0	(0xAA)
+#define P5_WF0BMR1	(0xAC)
+#define P5_WF0CR	(0xAE)
+#define P5_WF0OBR	(0xB0)
+#define P5_WF1BMR0	(0xB2)
+#define P5_WF1BMR1	(0xB4)
+#define P5_WF1CR	(0xB6)
+#define P5_WF1OBR	(0xB8)
+#define P5_WF2BMR0	(0xBA)
+#define P5_WF2BMR1	(0xBC)
+
+	/* Definition of PAGE6 */
+#define P6_WF2CR	(0xC2)
+#define P6_WF2OBR	(0xC4)
+#define P6_WF3BMR0	(0xC6)
+#define P6_WF3BMR1	(0xC8)
+#define P6_WF3CR	(0xCA)
+#define P6_WF3OBR	(0xCC)
+#define P6_WF4BMR0	(0xCE)
+#define P6_WF4BMR1	(0xD0)
+#define P6_WF4CR	(0xD2)
+#define P6_WF4OBR	(0xD4)
+#define P6_WF5BMR0	(0xD6)
+#define P6_WF5BMR1	(0xD8)
+#define P6_WF5CR	(0xDA)
+#define P6_WF5OBR	(0xDC)
+
+/* Definition of PAGE7 */
+#define P7_WF6BMR0	(0xE2)
+#define P7_WF6BMR1	(0xE4)
+#define P7_WF6CR	(0xE6)
+#define P7_WF6OBR	(0xE8)
+#define P7_WF7BMR0	(0xEA)
+#define P7_WF7BMR1	(0xEC)
+#define P7_WF7CR	(0xEE)
+#define P7_WF7OBR	(0xF0)
+#define P7_WFR01	(0xF2)
+#define P7_WFR23	(0xF4)
+#define P7_WFR45	(0xF6)
+#define P7_WFR67	(0xF8)
+#define P7_WFPC0	(0xFA)
+#define P7_WFPC1	(0xFC)
+
+/* Tx headers structure */
+struct tx_sop_header {
+	/* bit 15-11: flags, bit 10-0: packet length */
+	u16 flags_len;
+	/* bit 15-11: sequence number, bit 11-0: packet length bar */
+	u16 seq_lenbar;
+} __packed;
+
+struct tx_segment_header {
+	/* bit 15-14: flags, bit 13-11: segment number */
+	/* bit 10-0: segment length */
+	u16 flags_seqnum_seglen;
+	/* bit 15-14: end offset, bit 13-11: start offset */
+	/* bit 10-0: segment length bar */
+	u16 eo_so_seglenbar;
+} __packed;
+
+struct tx_eop_header {
+	/* bit 15-11: sequence number, bit 10-0: packet length */
+	u16 seq_len;
+	/* bit 15-11: sequence number bar, bit 10-0: packet length bar */
+	u16 seqbar_lenbar;
+} __packed;
+
+struct tx_pkt_info {
+	struct tx_sop_header sop;
+	struct tx_segment_header seg;
+	struct tx_eop_header eop;
+	u16 pkt_len;
+	u16 seq_num;
+} __packed;
+
+/* Rx headers structure */
+struct rx_header {
+	u16 flags_len;
+	u16 seq_lenbar;
+	u16 flags;
+} __packed;
+
+extern unsigned long ax88796c_no_regs_mask[];
+
+#endif /* #ifndef _AX88796C_MAIN_H */
diff --git a/drivers/net/ethernet/asix/ax88796c_spi.c b/drivers/net/ethernet/asix/ax88796c_spi.c
new file mode 100644
index 000000000000..829494e624c5
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_spi.c
@@ -0,0 +1,112 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#define pr_fmt(fmt)	"ax88796c: " fmt
+
+#include <linux/string.h>
+#include <linux/spi/spi.h>
+
+#include "ax88796c_spi.h"
+
+const u8 ax88796c_rx_cmd_buf[5] = {AX_SPICMD_READ_RXQ, 0xFF, 0xFF, 0xFF, 0xFF};
+const u8 ax88796c_tx_cmd_buf[4] = {AX_SPICMD_WRITE_TXQ, 0xFF, 0xFF, 0xFF};
+
+/* driver bus management functions */
+int axspi_wakeup(struct axspi_data *ax_spi)
+{
+	int ret;
+
+	ax_spi->cmd_buf[0] = AX_SPICMD_EXIT_PWD;	/* OP */
+	ret = spi_write(ax_spi->spi, ax_spi->cmd_buf, 1);
+	if (ret)
+		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
+	return ret;
+}
+
+int axspi_read_status(struct axspi_data *ax_spi, struct spi_status *status)
+{
+	int ret;
+
+	/* OP */
+	ax_spi->cmd_buf[0] = AX_SPICMD_READ_STATUS;
+	ret = spi_write_then_read(ax_spi->spi, ax_spi->cmd_buf, 1, (u8 *)&status, 3);
+	if (ret)
+		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
+	else
+		le16_to_cpus(&status->isr);
+
+	return ret;
+}
+
+int axspi_read_rxq(struct axspi_data *ax_spi, void *data, int len)
+{
+	struct spi_transfer *xfer = ax_spi->spi_rx_xfer;
+	int ret;
+
+	memcpy(ax_spi->cmd_buf, ax88796c_rx_cmd_buf, 5);
+
+	xfer->tx_buf = ax_spi->cmd_buf;
+	xfer->rx_buf = NULL;
+	xfer->len = ax_spi->comp ? 2 : 5;
+	xfer->bits_per_word = 8;
+	spi_message_add_tail(xfer, &ax_spi->rx_msg);
+
+	xfer++;
+	xfer->rx_buf = data;
+	xfer->tx_buf = NULL;
+	xfer->len = len;
+	xfer->bits_per_word = 8;
+	spi_message_add_tail(xfer, &ax_spi->rx_msg);
+	ret = spi_sync(ax_spi->spi, &ax_spi->rx_msg);
+	if (ret)
+		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
+
+	return ret;
+}
+
+int axspi_write_txq(const struct axspi_data *ax_spi, void *data, int len)
+{
+	return spi_write(ax_spi->spi, data, len);
+}
+
+u16 axspi_read_reg(struct axspi_data *ax_spi, u8 reg)
+{
+	int ret;
+	int len = ax_spi->comp ? 3 : 4;
+
+	ax_spi->cmd_buf[0] = 0x03;	/* OP code read register */
+	ax_spi->cmd_buf[1] = reg;	/* register address */
+	ax_spi->cmd_buf[2] = 0xFF;	/* dumy cycle */
+	ax_spi->cmd_buf[3] = 0xFF;	/* dumy cycle */
+	ret = spi_write_then_read(ax_spi->spi,
+				  ax_spi->cmd_buf, len,
+				  ax_spi->rx_buf, 2);
+	if (ret)
+		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
+	else
+		le16_to_cpus(ax_spi->rx_buf);
+
+	return *(u16 *)ax_spi->rx_buf;
+}
+
+int axspi_write_reg(struct axspi_data *ax_spi, u8 reg, u16 value)
+{
+	int ret;
+
+	memset(ax_spi->cmd_buf, 0, sizeof(ax_spi->cmd_buf));
+	ax_spi->cmd_buf[0] = AX_SPICMD_WRITE_REG;	/* OP code read register */
+	ax_spi->cmd_buf[1] = reg;			/* register address */
+	ax_spi->cmd_buf[2] = value;
+	ax_spi->cmd_buf[3] = value >> 8;
+
+	ret = spi_write(ax_spi->spi, ax_spi->cmd_buf, 4);
+	if (ret)
+		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
+	return ret;
+}
+
diff --git a/drivers/net/ethernet/asix/ax88796c_spi.h b/drivers/net/ethernet/asix/ax88796c_spi.h
new file mode 100644
index 000000000000..5bcf91f603fb
--- /dev/null
+++ b/drivers/net/ethernet/asix/ax88796c_spi.h
@@ -0,0 +1,69 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2010 ASIX Electronics Corporation
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ *
+ * ASIX AX88796C SPI Fast Ethernet Linux driver
+ */
+
+#ifndef _AX88796C_SPI_H
+#define _AX88796C_SPI_H
+
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+
+/* Definition of SPI command */
+#define AX_SPICMD_WRITE_TXQ		0x02
+#define AX_SPICMD_READ_REG		0x03
+#define AX_SPICMD_READ_STATUS		0x05
+#define AX_SPICMD_READ_RXQ		0x0B
+#define AX_SPICMD_BIDIR_WRQ		0xB2
+#define AX_SPICMD_WRITE_REG		0xD8
+#define AX_SPICMD_EXIT_PWD		0xAB
+
+extern const u8 ax88796c_rx_cmd_buf[];
+extern const u8 ax88796c_tx_cmd_buf[];
+
+struct axspi_data {
+	struct spi_device	*spi;
+	struct spi_message	rx_msg;
+	struct spi_transfer	spi_rx_xfer[2];
+	u8			cmd_buf[6];
+	u8			rx_buf[6];
+	u8			comp;
+};
+
+struct spi_status {
+	u16 isr;
+	u8 status;
+#	define AX_STATUS_READY		0x80
+};
+
+int axspi_read_rxq(struct axspi_data *ax_spi, void *data, int len);
+int axspi_write_txq(const struct axspi_data *ax_spi, void *data, int len);
+u16 axspi_read_reg(struct axspi_data *ax_spi, u8 reg);
+int axspi_write_reg(struct axspi_data *ax_spi, u8 reg, u16 value);
+int axspi_read_status(struct axspi_data *ax_spi, struct spi_status *status);
+int axspi_wakeup(struct axspi_data *ax_spi);
+
+static inline u16 AX_READ(struct axspi_data *ax_spi, u8 offset)
+{
+	return axspi_read_reg(ax_spi, offset);
+}
+
+static inline int AX_WRITE(struct axspi_data *ax_spi, u16 value, u8 offset)
+{
+	return axspi_write_reg(ax_spi, offset, value);
+}
+
+static inline int AX_READ_STATUS(struct axspi_data *ax_spi,
+				 struct spi_status *status)
+{
+	return axspi_read_status(ax_spi, status);
+}
+
+static inline int AX_WAKEUP(struct axspi_data *ax_spi)
+{
+	return axspi_wakeup(ax_spi);
+}
+#endif
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 9ca87bc73c44..f7621c3a938e 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -221,6 +221,7 @@  enum tunable_id {
 	ETHTOOL_RX_COPYBREAK,
 	ETHTOOL_TX_COPYBREAK,
 	ETHTOOL_PFC_PREVENTION_TOUT, /* timeout in msecs */
+	ETHTOOL_SPI_COMPRESSION,     /* SPI transfer compression */
 	/*
 	 * Add your fresh new tunable attribute above and remember to update
 	 * tunable_strings[] in net/core/ethtool.c
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 24036e3055a1..bd49f83d7daa 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -83,6 +83,7 @@  tunable_strings[__ETHTOOL_TUNABLE_COUNT][ETH_GSTRING_LEN] = {
 	[ETHTOOL_RX_COPYBREAK]	= "rx-copybreak",
 	[ETHTOOL_TX_COPYBREAK]	= "tx-copybreak",
 	[ETHTOOL_PFC_PREVENTION_TOUT] = "pfc-prevention-tout",
+	[ETHTOOL_SPI_COMPRESSION] = "spi-compression",
 };
 
 const char