[v2,4/5] net: hpe: Add GXP UMAC Driver

diff --git a/drivers/net/ethernet/hpe/Kconfig b/drivers/net/ethernet/hpe/Kconfig
new file mode 100644
index 000000000000..c04aa22ce02f
--- /dev/null
+++ b/drivers/net/ethernet/hpe/Kconfig
@@ -0,0 +1,32 @@ 
+config NET_VENDOR_HPE
+	bool "HPE device"
+	default y
+	depends on ARCH_HPE
+	help
+	  Say y here to support the HPE network devices.
+	  The GXP contains two Ethernet MACs that can be
+	  connected externally to several physical devices.
+	  From an external interface perspective the BMC
+	  provides two SERDES interface connections capable
+	  of either SGMII or 1000Base-X operation. The BMC
+	  also provides a RMII interface for sideband
+	  connections to external Ethernet controllers.
+
+if NET_VENDOR_HPE
+
+config GXP_UMAC
+	tristate "GXP UMAC support"
+	depends on ARCH_HPE
+	select CRC32
+	select MII
+	select PHYLIB
+	select GXP_UMAC_MDIO
+	help
+	  Say y here to support the GXP UMACs interface. The
+	  primary MAC (umac0) can be mapped to either
+	  SGMII/1000-BaseX SERDES interface. The secondary MAC
+	  (umac1) can be mapped to only the second
+	  SGMII/1000-Base X Serdes interface or it can be
+	  mapped for RMII sideband.
+
+endif
diff --git a/drivers/net/ethernet/hpe/Makefile b/drivers/net/ethernet/hpe/Makefile
new file mode 100644
index 000000000000..e84bb86f82bc
--- /dev/null
+++ b/drivers/net/ethernet/hpe/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_GXP_UMAC) += gxp-umac.o
diff --git a/drivers/net/ethernet/hpe/gxp-umac.c b/drivers/net/ethernet/hpe/gxp-umac.c
new file mode 100644
index 000000000000..851c41cfcdf9
--- /dev/null
+++ b/drivers/net/ethernet/hpe/gxp-umac.c
@@ -0,0 +1,889 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2023 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/dma-mapping.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <net/ncsi.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/phy.h>
+#include "gxp-umac.h"
+
+#define PHY_88E1514_COPPER_CONTROL_REG		0
+#define PHY_88E1514_PAGE_ADDRESS		22
+
+#define PHY_88E1514_GENERAL_CONTROL_REG1	20
+
+#define DRV_MODULE_NAME		"gxp-umac"
+#define DRV_MODULE_VERSION	"0.1"
+
+#define NUMBER_OF_PORTS 2
+#define EXTERNAL_PORT 1
+#define INTERNAL_PORT 0
+
+struct umac_priv {
+	void __iomem *base;
+	int irq;
+	struct platform_device *pdev;
+	struct umac_tx_descs *tx_descs;
+	struct umac_rx_descs *rx_descs;
+	dma_addr_t tx_descs_dma_addr;
+	dma_addr_t rx_descs_dma_addr;
+	unsigned int tx_cur;
+	unsigned int tx_done;
+	unsigned int rx_cur;
+	struct napi_struct napi;
+	struct net_device *ndev;
+	struct phy_device *phy_dev;
+	struct phy_device *int_phy_dev;
+	struct ncsi_dev *ncsidev;
+	bool use_ncsi;
+};
+
+static void umac_get_drvinfo(struct net_device *ndev,
+			     struct ethtool_drvinfo *info)
+{
+	strscpy(info->driver, DRV_MODULE_NAME, sizeof(info->driver));
+	strscpy(info->version, DRV_MODULE_VERSION, sizeof(info->version));
+}
+
+static int umac_get_link_ksettings(struct net_device *ndev,
+				   struct ethtool_link_ksettings *cmd)
+{
+	phy_ethtool_ksettings_get(ndev->phydev, cmd);
+	return 0;
+}
+
+static int umac_set_link_ksettings(struct net_device *ndev,
+				   const struct ethtool_link_ksettings *cmd)
+{
+	return phy_ethtool_ksettings_set(ndev->phydev, cmd);
+}
+
+static int umac_nway_reset(struct net_device *ndev)
+{
+	return genphy_restart_aneg(ndev->phydev);
+}
+
+static u32 umac_get_link(struct net_device *ndev)
+{
+	int err;
+
+	err = genphy_update_link(ndev->phydev);
+	if (err)
+		return ethtool_op_get_link(ndev);
+
+	return ndev->phydev->link;
+}
+
+static struct net_device_stats *umac_get_stats(struct net_device *ndev)
+{
+	return &ndev->stats;
+}
+
+static int umac_ioctl(struct net_device *ndev, struct ifreq *ifr, int cmd)
+{
+	if (!netif_running(ndev))
+		return -EINVAL;
+
+	if (!ndev->phydev)
+		return -ENODEV;
+
+	return phy_mii_ioctl(ndev->phydev, ifr, cmd);
+}
+
+static void umac_set_mac_address(struct net_device *ndev, void *p_addr)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	char *addr = (char *)p_addr;
+	unsigned int value;
+
+	/* update address to register */
+	value = addr[0] << 8 | addr[1];
+	writel(value, umac->base + UMAC_MAC_ADDR_HI);
+	value = addr[2] << 8 | addr[3];
+	writel(value, umac->base + UMAC_MAC_ADDR_MID);
+	value = addr[4] << 8 | addr[5];
+	writel(value, umac->base + UMAC_MAC_ADDR_LO);
+}
+
+static int umac_eth_mac_addr(struct net_device *ndev, void *p)
+{
+	struct sockaddr *addr = p;
+	int ret;
+
+	ret = eth_prepare_mac_addr_change(ndev, p);
+	if (ret < 0)
+		return ret;
+
+	eth_commit_mac_addr_change(ndev, p);
+	umac_set_mac_address(ndev, addr->sa_data);
+
+	return 0;
+}
+
+static void umac_channel_enable(struct umac_priv *umac)
+{
+	unsigned int value;
+
+	value = readl(umac->base + UMAC_CONFIG_STATUS);
+	value |= UMAC_CFG_TXEN | UMAC_CFG_RXEN;
+	writel(value, umac->base + UMAC_CONFIG_STATUS);
+
+	/* start processing by writing the ring prompt register */
+	writel(0, umac->base + UMAC_RING_PROMPT);
+}
+
+static void umac_channel_disable(struct umac_priv *umac)
+{
+	writel(0, umac->base + UMAC_CONFIG_STATUS);
+}
+
+static int umac_init_ring_discriptor(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	struct platform_device *pdev = umac->pdev;
+
+	struct umac_tx_desc_entry *ptxdesc;
+	struct umac_rx_desc_entry *prxdesc;
+
+	unsigned int i;
+
+	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32))) {
+		netdev_err(ndev, "No suitable DMA available\n");
+		return -ENOMEM;
+	}
+
+	umac->tx_descs = dma_alloc_coherent(&pdev->dev,
+					    sizeof(struct umac_tx_descs),
+					&umac->tx_descs_dma_addr, GFP_KERNEL);
+	if (!umac->tx_descs)
+		return -ENOMEM;
+
+	umac->rx_descs = dma_alloc_coherent(&pdev->dev,
+					    sizeof(struct umac_rx_descs),
+					&umac->rx_descs_dma_addr, GFP_KERNEL);
+	if (!umac->rx_descs) {
+		dma_free_coherent(&pdev->dev, sizeof(struct umac_tx_descs),
+				  umac->tx_descs,
+					umac->tx_descs_dma_addr);
+		return -ENOMEM;
+	}
+
+	for (i = 0; i < UMAC_MAX_TX_DESC_ENTRIES; i++) {
+		ptxdesc = &umac->tx_descs->entrylist[i];
+		ptxdesc->dmaaddress = cpu_to_le32(umac->tx_descs_dma_addr +
+						offsetof(struct umac_tx_descs,
+							 framelist[i][0]));
+	}
+
+	for (i = 0; i < UMAC_MAX_RX_DESC_ENTRIES; i++) {
+		prxdesc = &umac->rx_descs->entrylist[i];
+		prxdesc->dmaaddress = cpu_to_le32(umac->rx_descs_dma_addr +
+						offsetof(struct umac_rx_descs,
+							 framelist[i][0]));
+		prxdesc->status = UMAC_RING_ENTRY_HW_OWN;
+		prxdesc->count = UMAC_MAX_RX_FRAME_SIZE;
+	}
+
+	umac->tx_cur = 0;
+	umac->tx_done = 0;
+	umac->rx_cur = 0;
+
+	return 0;
+}
+
+static int umac_int_phy_init(struct umac_priv *umac)
+{
+	struct phy_device *phy_dev = umac->int_phy_dev;
+	unsigned int value;
+
+	value = phy_read(phy_dev, 0);
+	if (value & 0x4000)
+		pr_info("Internal PHY loopback is enabled - clearing\n");
+
+	value &= ~0x4000; /* disable loopback */
+	phy_write(phy_dev, 0, value);
+
+	value = phy_read(phy_dev, 0);
+	value |= 0x1000; /* set aneg enable */
+	value |= 0x8000; /* SW reset */
+	phy_write(phy_dev, 0, value);
+
+	do {
+		value = phy_read(phy_dev, 0);
+	} while (value & 0x8000);
+
+	return 0;
+}
+
+static int umac_phy_fixup(struct phy_device *phy_dev)
+{
+	unsigned int value;
+
+	/* set phy mode to SGMII to copper */
+	/* set page to 18 by writing 18 to register 22 */
+	phy_write(phy_dev, PHY_88E1514_PAGE_ADDRESS, 18);
+	value = phy_read(phy_dev, PHY_88E1514_GENERAL_CONTROL_REG1);
+	value &= ~0x07;
+	value |= 0x01;
+	phy_write(phy_dev, PHY_88E1514_GENERAL_CONTROL_REG1, value);
+
+	/* perform mode reset by setting bit 15 in general_control_reg1 */
+	phy_write(phy_dev, PHY_88E1514_GENERAL_CONTROL_REG1, value | 0x8000);
+
+	do {
+		value = phy_read(phy_dev, PHY_88E1514_GENERAL_CONTROL_REG1);
+	} while (value & 0x8000);
+
+	/* after setting the mode, must perform a SW reset */
+	phy_write(phy_dev, PHY_88E1514_PAGE_ADDRESS, 0); /* set page to 0 */
+
+	value = phy_read(phy_dev, PHY_88E1514_COPPER_CONTROL_REG);
+	value |= 0x8000;
+	phy_write(phy_dev, PHY_88E1514_COPPER_CONTROL_REG, value);
+
+	do {
+		value = phy_read(phy_dev, PHY_88E1514_COPPER_CONTROL_REG);
+	} while (value & 0x8000);
+
+	return 0;
+}
+
+static int umac_init_hw(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	unsigned int value;
+
+	/* initialize tx and rx rings to first entry */
+	writel(0, umac->base + UMAC_RING_PTR);
+
+	/* clear the missed bit */
+	writel(0, umac->base + UMAC_CLEAR_STATUS);
+
+	/* disable checksum generation */
+	writel(0, umac->base + UMAC_CKSUM_CONFIG);
+
+	/* write the ring size register */
+	value = ((UMAC_RING_SIZE_256 << UMAC_TX_RING_SIZE_SHIFT) &
+			UMAC_TX_RING_SIZE_MASK) |
+		((UMAC_RING_SIZE_256 << UMAC_RX_RING_SIZE_SHIFT) &
+			UMAC_RX_RING_SIZE_MASK);
+	writel(value, umac->base + UMAC_RING_SIZE);
+
+	/* write rx ring base address */
+	writel(umac->rx_descs_dma_addr,
+	       umac->base + UMAC_RX_RING_ADDR);
+
+	/* write tx ring base address */
+	writel(umac->tx_descs_dma_addr,
+	       umac->base + UMAC_TX_RING_ADDR);
+
+	/* write burst size */
+	writel(0x22, umac->base + UMAC_DMA_CONFIG);
+
+	umac_channel_disable(umac);
+
+	/* disable clocks and gigabit mode (leave channels disabled) */
+	value = readl(umac->base + UMAC_CONFIG_STATUS);
+	value &= 0xfffff9ff;
+	writel(value, umac->base + UMAC_CONFIG_STATUS);
+	udelay(2);
+
+	if (umac->use_ncsi) {
+		/* set correct tx clock */
+		value &= UMAC_CFG_TX_CLK_EN;
+		value &= ~UMAC_CFG_GTX_CLK_EN;
+		value &= ~UMAC_CFG_GIGABIT_MODE; /* RMII mode */
+		value |= UMAC_CFG_FULL_DUPLEX; /* full duplex */
+	} else {
+		if (ndev->phydev->duplex)
+			value |= UMAC_CFG_FULL_DUPLEX;
+		else
+			value &= ~UMAC_CFG_FULL_DUPLEX;
+
+		if (ndev->phydev->speed == SPEED_1000) {
+			value &= ~UMAC_CFG_TX_CLK_EN;
+			value |= UMAC_CFG_GTX_CLK_EN;
+			value |= UMAC_CFG_GIGABIT_MODE;
+		} else {
+			value |= UMAC_CFG_TX_CLK_EN;
+			value &= ~UMAC_CFG_GTX_CLK_EN;
+			value &= ~UMAC_CFG_GIGABIT_MODE;
+		}
+	}
+	writel(value, umac->base + UMAC_CONFIG_STATUS);
+	udelay(2);
+
+	umac_channel_enable(umac);
+
+	return 0;
+}
+
+static int umac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	struct umac_tx_desc_entry *ptxdesc;
+	unsigned int length;
+	u8 *pframe;
+
+	ptxdesc = &umac->tx_descs->entrylist[umac->tx_cur];
+	pframe = umac->tx_descs->framelist[umac->tx_cur];
+
+	length = skb->len;
+	if (length > 1514) {
+		netdev_err(ndev, "send data %d bytes > 1514, clamp it to 1514\n",
+			   skb->len);
+		length = 1514;
+	}
+
+	memset(pframe, 0, UMAC_MAX_FRAME_SIZE);
+	memcpy(pframe, skb->data, length);
+
+	if (length < ETH_ZLEN)
+		length = ETH_ZLEN; /* minimum tx byte */
+
+	ptxdesc->count = length;
+	ptxdesc->status = UMAC_RING_ENTRY_HW_OWN;
+	ptxdesc->cksumoffset = 0; /* disable checksum generation */
+
+	umac->tx_cur++;
+	if (umac->tx_cur >= UMAC_MAX_TX_DESC_ENTRIES)
+		umac->tx_cur = 0;
+
+	/* if current tx ring buffer is full, stop the queue */
+	ptxdesc = &umac->tx_descs->entrylist[umac->tx_cur];
+	if (ptxdesc->status & UMAC_RING_ENTRY_HW_OWN)
+		netif_stop_queue(ndev);
+
+	/* start processing by writing the ring prompt register */
+	writel(0, umac->base + UMAC_RING_PROMPT);
+	dev_kfree_skb(skb);
+
+	return NETDEV_TX_OK;
+}
+
+static int umac_rx(struct net_device *ndev, int budget)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+
+	struct umac_rx_desc_entry *prxdesc;
+	struct sk_buff *skb;
+
+	unsigned int rxlength;
+	int rxpktcount = 0;
+	u8 *pframe;
+	u8 *skb_buf;
+
+	prxdesc = &umac->rx_descs->entrylist[umac->rx_cur];
+	pframe = umac->rx_descs->framelist[umac->rx_cur];
+
+	while (!(prxdesc->status & UMAC_RING_ENTRY_HW_OWN)) {
+		rxlength = prxdesc->count;
+		skb = netdev_alloc_skb(ndev, rxlength);
+		if (!skb) {
+			/* run out of memory */
+			ndev->stats.rx_dropped++;
+			return rxpktcount;
+		}
+
+		/* make 16 bytes aligned for 14 bytes ethernet header */
+		skb_buf = skb_put(skb, rxlength);
+		memcpy(skb_buf, pframe, rxlength);
+
+		skb->protocol = eth_type_trans(skb, ndev);
+		netif_receive_skb(skb);
+		rxpktcount++;
+
+		prxdesc->status = UMAC_RING_ENTRY_HW_OWN;
+		prxdesc->count = UMAC_MAX_FRAME_SIZE;
+
+		ndev->stats.rx_packets++;
+		ndev->stats.rx_bytes += rxlength;
+
+		/* move to next buffer */
+		umac->rx_cur++;
+		if (umac->rx_cur >= UMAC_MAX_RX_DESC_ENTRIES)
+			umac->rx_cur = 0;
+
+		if (rxpktcount >= budget)
+			break;
+
+		prxdesc = &umac->rx_descs->entrylist[umac->rx_cur];
+		pframe = umac->rx_descs->framelist[umac->rx_cur];
+	}
+	/* start processing by writing the ring prompt register */
+	writel(0, umac->base + UMAC_RING_PROMPT);
+
+	return rxpktcount;
+}
+
+static void umac_tx_done(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+
+	unsigned int txptr;
+	unsigned int value;
+	struct umac_tx_desc_entry *ptxdesc;
+
+	value = readl(umac->base + UMAC_RING_PTR);
+	txptr = (value & UMAC_TX_RING_PTR_MASK) >> UMAC_TX_RING_PTR_SHIFT;
+
+	ptxdesc = &umac->tx_descs->entrylist[umac->tx_done];
+
+	while (!(ptxdesc->status & UMAC_RING_ENTRY_HW_OWN)) {
+		if (umac->tx_done == txptr)
+			break;
+
+		ndev->stats.tx_packets++;
+		ndev->stats.tx_bytes += ptxdesc->count;
+
+		umac->tx_done++;
+		if (umac->tx_done >= UMAC_MAX_TX_DESC_ENTRIES)
+			umac->tx_done = 0;
+		ptxdesc = &umac->tx_descs->entrylist[umac->tx_done];
+	}
+
+	/* clear tx interrupt */
+	value = readl(umac->base + UMAC_INTERRUPT);
+	value &= ~UMAC_TX_INT;
+	writel(value, umac->base + UMAC_INTERRUPT);
+
+	if (netif_queue_stopped(ndev))
+		netif_wake_queue(ndev);
+}
+
+static void umac_irq_enable(struct umac_priv *umac)
+{
+	unsigned int value;
+
+	/* enable interrupt */
+	value = readl(umac->base + UMAC_INTERRUPT);
+	value |= (UMAC_RX_INTEN | UMAC_TX_INTEN);
+	writel(value, umac->base + UMAC_INTERRUPT);
+}
+
+static void umac_irq_disable(struct umac_priv *umac)
+{
+	unsigned int value;
+
+	/* clear and disable interrupt */
+	value = readl(umac->base + UMAC_INTERRUPT);
+	value |= (UMAC_RX_INT | UMAC_TX_INT);
+	value &= ~(UMAC_RX_INTEN | UMAC_TX_INTEN);
+	writel(value, umac->base + UMAC_INTERRUPT);
+}
+
+static irqreturn_t umac_interrupt(int irq, void *p_ndev)
+{
+	struct net_device *ndev = (struct net_device *)p_ndev;
+	struct umac_priv *umac = netdev_priv(ndev);
+
+	if (umac->use_ncsi || netif_running(ndev)) {
+		umac_irq_disable(umac);
+		napi_schedule(&umac->napi);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int umac_poll(struct napi_struct *napi, int budget)
+{
+	struct umac_priv *umac = container_of(napi, struct umac_priv, napi);
+	struct net_device *ndev = umac->ndev;
+	unsigned int value;
+	int rx_done;
+
+	umac_tx_done(ndev);
+
+	rx_done = umac_rx(ndev, budget);
+
+	if (rx_done < budget) {
+		napi_complete_done(napi, rx_done);
+		/* clear rx interrupt */
+		value = readl(umac->base + UMAC_INTERRUPT);
+		value &= ~UMAC_RX_INT;
+		writel(value, umac->base + UMAC_INTERRUPT);
+
+		/* enable interrupt */
+		umac_irq_enable(umac);
+	}
+
+	return rx_done;
+}
+
+static int umac_open(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	int err;
+
+	if (request_irq(ndev->irq, umac_interrupt, 0x0, ndev->name, ndev)) {
+		netdev_err(ndev, "failed to register irq\n");
+		return -EAGAIN;
+	}
+
+	umac_init_ring_discriptor(ndev);
+	umac_init_hw(ndev);
+
+	if (umac->use_ncsi)
+		netif_carrier_on(ndev);
+	else
+		phy_start(ndev->phydev);
+
+	napi_enable(&umac->napi);
+	netif_start_queue(ndev);
+	umac_irq_enable(umac);
+
+	if (umac->use_ncsi) {
+		err = ncsi_start_dev(umac->ncsidev);
+		if (err) {
+			netdev_err(ndev, "failed to start ncsi\n");
+			free_irq(ndev->irq, ndev);
+			return err;
+		}
+	}
+
+	netdev_info(ndev, "%s is OPENED\n", ndev->name);
+	return 0;
+}
+
+static int umac_stop(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	struct platform_device *pdev = umac->pdev;
+
+	dma_free_coherent(&pdev->dev, sizeof(struct umac_tx_descs),
+			  umac->tx_descs, umac->tx_descs_dma_addr);
+	dma_free_coherent(&pdev->dev, sizeof(struct umac_rx_descs),
+			  umac->rx_descs, umac->rx_descs_dma_addr);
+	netif_stop_queue(ndev);
+
+	if (umac->use_ncsi)
+		ncsi_stop_dev(umac->ncsidev);
+	else
+		phy_stop(ndev->phydev);
+	umac_irq_disable(umac);
+	umac_channel_disable(umac);
+	napi_disable(&umac->napi);
+
+	free_irq(ndev->irq, ndev);
+
+	return 0;
+}
+
+static const struct ethtool_ops umac_ethtool_ops = {
+	.get_ts_info	= ethtool_op_get_ts_info,
+	.get_link_ksettings	= umac_get_link_ksettings,
+	.set_link_ksettings	= umac_set_link_ksettings,
+	.get_drvinfo	= umac_get_drvinfo,
+	.nway_reset	= umac_nway_reset,
+	.get_link	= umac_get_link,
+};
+
+static const struct net_device_ops umac_netdev_ops = {
+	.ndo_open		= umac_open,
+	.ndo_stop		= umac_stop,
+	.ndo_start_xmit		= umac_start_xmit,
+	.ndo_get_stats		= umac_get_stats,
+	.ndo_do_ioctl		= umac_ioctl,
+	.ndo_validate_addr	= eth_validate_addr,
+	.ndo_set_mac_address	= umac_eth_mac_addr,
+};
+
+static int umac_init_mac_address(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	struct platform_device *pdev = umac->pdev;
+	char addr[ETH_ALEN];
+	int err;
+
+	err = of_get_mac_address(pdev->dev.of_node, addr);
+	if (err)
+		netdev_err(ndev, "Failed to get address from device-tree: %d\n",
+			   err);
+
+	if (is_valid_ether_addr(addr)) {
+		dev_addr_set(ndev, addr);
+		netdev_info(ndev,
+			    "Read MAC address %pM from DTB\n", ndev->dev_addr);
+	} else {
+		eth_hw_addr_random(ndev);
+		netdev_info(ndev, "Generated random MAC address %pM\n",
+			    ndev->dev_addr);
+	}
+
+	dev_addr_set(ndev, addr);
+	umac_set_mac_address(ndev, addr);
+
+	return 0;
+}
+
+static void umac_ncsi_handler(struct ncsi_dev *ncsidev)
+{
+	if (unlikely(ncsidev->state != ncsi_dev_state_functional))
+		return;
+
+	netdev_info(ncsidev->dev, "NCSI interface %s\n",
+		    ncsidev->link_up ? "up" : "down");
+}
+
+static void umac_adjust_link(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	int value;
+
+	if (ndev->phydev->link) {
+		/* disable both clock */
+		value = readl(umac->base + UMAC_CONFIG_STATUS);
+		value &= 0xfffff9ff;
+		writel(value, umac->base + UMAC_CONFIG_STATUS);
+		udelay(2);
+
+		if (ndev->phydev->duplex)
+			value |= UMAC_CFG_FULL_DUPLEX;
+		else
+			value &= ~UMAC_CFG_FULL_DUPLEX;
+
+		switch (ndev->phydev->speed) {
+		case SPEED_1000:
+			value &= ~UMAC_CFG_TX_CLK_EN;
+			value |= UMAC_CFG_GTX_CLK_EN;
+			value |= UMAC_CFG_GIGABIT_MODE;
+			break;
+		case SPEED_100:
+			value |= UMAC_CFG_TX_CLK_EN;
+			value &= ~UMAC_CFG_GTX_CLK_EN;
+			value &= ~UMAC_CFG_GIGABIT_MODE;
+			break;
+		}
+		/* update duplex and gigabit_mode to umac */
+		writel(value, umac->base + UMAC_CONFIG_STATUS);
+		udelay(2);
+
+		netif_carrier_on(ndev);
+	} else {
+		/* disable both clock */
+		value = readl(umac->base + UMAC_CONFIG_STATUS);
+		value &= 0xfffff9ff;
+		writel(value, umac->base + UMAC_CONFIG_STATUS);
+		udelay(2);
+
+		value &= ~UMAC_CFG_FULL_DUPLEX;
+		value &= ~UMAC_CFG_GTX_CLK_EN;
+		value &= ~UMAC_CFG_GIGABIT_MODE;
+		value |= UMAC_CFG_TX_CLK_EN;
+		writel(value, umac->base + UMAC_CONFIG_STATUS);
+		udelay(2);
+
+		netif_carrier_off(ndev);
+	}
+}
+
+static struct device_node *gxp_umac_get_eth_child_node(struct device_node *ether_np, int id)
+{
+	struct device_node *port_np;
+	int port_id;
+
+	for_each_child_of_node(ether_np, port_np) {
+		/* It is not a 'port' node, continue. */
+		if (strcmp(port_np->name, "port"))
+			continue;
+		if (of_property_read_u32(port_np, "reg", &port_id) < 0)
+			continue;
+
+		if (port_id == id)
+			return port_np;
+	}
+
+	/* Not found! */
+	return NULL;
+}
+
+static int umac_setup_phy(struct net_device *ndev)
+{
+	struct umac_priv *umac = netdev_priv(ndev);
+	struct platform_device *pdev = umac->pdev;
+	struct device_node *phy_handle;
+	phy_interface_t interface;
+	struct device_node *eth_ports_np;
+	struct device_node *port_np;
+	int ret;
+	int i;
+
+	/* Get child node ethernet-ports. */
+	eth_ports_np = of_get_child_by_name(pdev->dev.of_node, "ethernet-ports");
+	if (!eth_ports_np) {
+		dev_err(&pdev->dev, "No ethernet-ports child node found!\n");
+		return -ENODEV;
+	}
+
+	for (i = 0; i < NUMBER_OF_PORTS; i++) {
+		/* Get port@i of node ethernet-ports */
+		port_np = gxp_umac_get_eth_child_node(eth_ports_np, i);
+		if (!port_np)
+			break;
+
+		if (i == INTERNAL_PORT) {
+			phy_handle = of_parse_phandle(port_np, "phy-handle", 0);
+			if (phy_handle) {
+				umac->int_phy_dev = of_phy_find_device(phy_handle);
+				if (!umac->int_phy_dev)
+					return -ENODEV;
+
+				umac_int_phy_init(umac);
+			} else {
+				return dev_err_probe(&pdev->dev, PTR_ERR(phy_handle),
+						     "Failed to map phy-handle for port %d", i);
+			}
+		}
+
+		if (i == EXTERNAL_PORT) {
+			phy_handle = of_parse_phandle(port_np, "phy-handle", 0);
+			if (phy_handle) {
+				/* register the phy board fixup */
+				ret = phy_register_fixup_for_uid(0x01410dd1, 0xffffffff,
+								 umac_phy_fixup);
+				if (ret)
+					dev_err(&pdev->dev, "cannot register phy board fixup\n");
+
+				ret = of_get_phy_mode(phy_handle, &interface);
+				if (ret)
+					interface = PHY_INTERFACE_MODE_NA;
+
+				umac->phy_dev = of_phy_connect(ndev, phy_handle,
+							       &umac_adjust_link,
+							       0, interface);
+
+				if (!umac->phy_dev)
+					return -ENODEV;
+
+				/* If the specified phy-handle has a fixed-link declaration, use the
+				 * fixed-link properties to set the configuration for the PHY
+				 */
+				if (of_phy_is_fixed_link(phy_handle)) {
+					struct device_node *fixed_link_node =
+						of_get_child_by_name(phy_handle,
+								     "fixed-link");
+
+					if (of_property_read_u32(fixed_link_node, "speed",
+								 &umac->phy_dev->speed)) {
+						netdev_err(ndev, "Invalid fixed-link specified.\n");
+						return -EINVAL;
+					}
+					umac->phy_dev->duplex =
+						of_property_read_bool(fixed_link_node,
+								      "full-duplex");
+					umac->phy_dev->pause =
+						of_property_read_bool(fixed_link_node,
+								      "pause");
+					umac->phy_dev->asym_pause =
+						of_property_read_bool(fixed_link_node,
+								      "asym-pause");
+					umac->phy_dev->autoneg = AUTONEG_DISABLE;
+					__clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
+						    umac->phy_dev->advertising);
+				}
+			} else {
+				return dev_err_probe(&pdev->dev, PTR_ERR(phy_handle),
+						     "Failed to map phy-handle for port %d", i);
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int umac_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct net_device *ndev;
+	struct umac_priv *umac;
+	struct resource *res;
+	int ret;
+
+	ndev = devm_alloc_etherdev(dev, sizeof(*umac));
+	if (!ndev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+
+	umac = netdev_priv(ndev);
+	umac->pdev = pdev;
+	umac->ndev = ndev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		netdev_err(ndev, "failed to get I/O memory\n");
+		return -ENXIO;
+	}
+
+	umac->base = devm_ioremap_resource(&pdev->dev, res);
+	if (!umac->base) {
+		netdev_err(ndev, "failed to remap I/O memory\n");
+		return -EBUSY;
+	}
+
+	ndev->irq = platform_get_irq(pdev, 0);
+	if (ndev->irq < 0) {
+		netdev_err(ndev, "failed to get irq\n");
+		return -ENXIO;
+	}
+
+	platform_set_drvdata(pdev, ndev);
+
+	ndev->netdev_ops = &umac_netdev_ops;
+	ndev->ethtool_ops = &umac_ethtool_ops;
+
+	umac_init_mac_address(ndev);
+	umac_channel_disable(umac);
+	ret = umac_setup_phy(ndev);
+	if (ret != 0) {
+		netdev_err(ndev, "failed to setup phy ret=%d\n", ret);
+		return -ENODEV;
+	}
+
+	umac->use_ncsi = false;
+	if (of_get_property(pdev->dev.of_node, "use-ncsi", NULL)) {
+		if (!IS_ENABLED(CONFIG_NET_NCSI)) {
+			netdev_err(ndev, "NCSI stack not enabled\n");
+			return 0;
+		}
+
+		dev_info(&pdev->dev, "Using NCSI interface\n");
+		umac->use_ncsi = true;
+		umac->ncsidev = ncsi_register_dev(ndev, umac_ncsi_handler);
+		if (!umac->ncsidev)
+			return -ENODEV;
+	}
+
+	netif_napi_add(ndev, &umac->napi, umac_poll);
+	ret = devm_register_netdev(dev, ndev);
+	if (ret != 0)
+		netdev_err(ndev, "failed to register UMAC ret=%d\n", ret);
+
+	return ret;
+}
+
+static const struct of_device_id umac_of_matches[] = {
+	{ .compatible = "hpe,gxp-umac", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, umac_of_matches);
+
+static struct platform_driver umac_driver = {
+	.driver	= {
+		.name    = "gxp-umac",
+		.of_match_table = umac_of_matches,
+	},
+	.probe   = umac_probe,
+};
+
+module_platform_driver(umac_driver);
+
+MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com");
+MODULE_DESCRIPTION("HPE GXP UMAC driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/net/ethernet/hpe/gxp-umac.h b/drivers/net/ethernet/hpe/gxp-umac.h
new file mode 100644
index 000000000000..b8e313cfdcc6
--- /dev/null
+++ b/drivers/net/ethernet/hpe/gxp-umac.h
@@ -0,0 +1,89 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (C) 2023 Hewlett-Packard Development Company, L.P. */
+
+#ifndef _UMAC_H_
+#define _UMAC_H_
+
+#define UMAC_CONFIG_STATUS	0x00        /* R/W Configuration and Status
+					     * Register I
+					     */
+#define UMAC_CFG_TXEN		0x00001000  // transmit enable
+#define UMAC_CFG_RXEN		0x00000800  // receive enable
+#define UMAC_CFG_GTX_CLK_EN	0x00000400  // gigabit clock enable
+#define UMAC_CFG_TX_CLK_EN	0x00000200  // 10/100 clock enable
+#define UMAC_CFG_GIGABIT_MODE	0x00000004  // MAC gigabit mode enable
+#define UMAC_CFG_FULL_DUPLEX	0x00000001  // enable ignoring of collisions
+#define UMAC_RING_PTR		0x04        //  R/W Ring Pointer Register
+#define UMAC_TX_RING_PTR_MASK	0x7FFF0000  // transmit ring entry pointer
+#define UMAC_TX_RING_PTR_SHIFT	16
+#define UMAC_RX_RING_PTR_MASK	0x00007FFF  // receive ring entry pointer
+#define UMAC_RX_RING_PTR_SHIFT	0
+
+#define UMAC_CLEAR_STATUS	0x0C	//  W   Clear Status Register
+#define UMAC_RING_PROMPT	0x08	//  W	Ring Prompt Register
+#define UMAC_CKSUM_CONFIG	0x10	//  R/W	Checksum Config Register
+#define UMAC_RING_SIZE		0x14	//  R/W	Ring Size Register
+#define UMAC_TX_RING_SIZE_MASK	0xFF000000
+#define UMAC_TX_RING_SIZE_SHIFT	24
+#define UMAC_RX_RING_SIZE_MASK	0x00FF0000
+#define UMAC_RX_RING_SIZE_SHIFT	16
+#define UMAC_LAST_RX_PKT_SIZE	0x0000FFFF
+#define UMAC_RING_SIZE_256	0x3F
+
+#define UMAC_MAC_ADDR_HI	0x18	//  R/W	MAC Address[47:32] Register
+#define UMAC_MAC_ADDR_MID	0x1C	//  R/W	MAC Address[31:16] Register
+#define UMAC_MAC_ADDR_LO	0x20	//  R/W	MAC Address[15:0] Register
+#define UMAC_INTERRUPT		0x30	//  R/W	MAC Interrupt Configuration
+					// and Status Register
+#define UMAC_RX_INTEN		0x00000008
+#define UMAC_RX_INT		0x00000004
+#define UMAC_TX_INTEN		0x00000002
+#define UMAC_TX_INT		0x00000001
+
+#define UMAC_RX_RING_ADDR	0x4C	//  R/W	Rx Ring Base Address Register
+#define UMAC_TX_RING_ADDR	0x50	//  R/W	Tx Ring Base Address Register
+#define UMAC_DMA_CONFIG		0x54	//  R/W	DMA Config Register
+
+#define UMAC_MAX_TX_DESC_ENTRIES	0x100	/* 256,number of ring buffer
+						 *  entries supported
+						 */
+#define UMAC_MAX_RX_DESC_ENTRIES	0x100
+#define UMAC_MAX_TX_FRAME_SIZE		0x600
+#define UMAC_MAX_RX_FRAME_SIZE		0x600
+
+// ring status masks
+#define UMAC_RING_ENTRY_HW_OWN		0x8000
+
+// maximum ethernet frame size
+#define UMAC_MIN_FRAME_SIZE		60    // excludes preable, sfd, and fcs
+#define UMAC_MAX_PAYLOAD_SIZE		1500
+#define UMAC_MAX_FRAME_SIZE		1514  // excludes preable, sfd, and fcs
+
+struct umac_rx_desc_entry {
+	__le32  dmaaddress;   // Start address for DMA operationg
+	u16  status;       // Packet tx status and ownership flag
+	u16  count;        // Number of bytes received
+	u16  checksum;     // On-the-fly packet checksum
+	u16  control;      // Checksum-in-time flag
+	u32  reserved;
+} __aligned(16);
+
+struct umac_rx_descs {
+	struct umac_rx_desc_entry entrylist[UMAC_MAX_RX_DESC_ENTRIES];
+	u8 framelist[UMAC_MAX_RX_DESC_ENTRIES][UMAC_MAX_RX_FRAME_SIZE];
+} __packed;
+
+struct umac_tx_desc_entry {
+	__le32  dmaaddress;   // Start address for DMA operationg
+	u16  status;       // Packet rx status, type, and ownership flag
+	u16  count;        // Number of bytes received
+	u32  cksumoffset;  // Specifies where to place packet checksum
+	u32  reserved;
+} __aligned(16);
+
+struct umac_tx_descs {
+	struct umac_tx_desc_entry entrylist[UMAC_MAX_TX_DESC_ENTRIES];
+	u8 framelist[UMAC_MAX_TX_DESC_ENTRIES][UMAC_MAX_TX_FRAME_SIZE];
+} __packed;
+
+#endif