[PATCH v3 1/9] ethernet: add sun8i-emac driver

[Corentin Labbe]

This patch add support for sun8i-emac ethernet MAC hardware.
It could be found in Allwinner H3/A83T/A64 SoCs.

It supports 10/100/1000 Mbit/s speed with half/full duplex.
It can use an internal PHY (MII 10/100) or an external PHY
via RGMII/RMII.

Signed-off-by: Corentin Labbe <clabbe.montjoie@xxxxxxxxx>
---
 drivers/net/ethernet/allwinner/Kconfig      |   13 +
 drivers/net/ethernet/allwinner/Makefile     |    1 +
 drivers/net/ethernet/allwinner/sun8i-emac.c | 2255 +++++++++++++++++++++++++++
 3 files changed, 2269 insertions(+)
 create mode 100644 drivers/net/ethernet/allwinner/sun8i-emac.c

diff --git a/drivers/net/ethernet/allwinner/Kconfig b/drivers/net/ethernet/allwinner/Kconfig
index 47da7e7..060569c 100644
--- a/drivers/net/ethernet/allwinner/Kconfig
+++ b/drivers/net/ethernet/allwinner/Kconfig
@@ -33,4 +33,17 @@ config SUN4I_EMAC
           To compile this driver as a module, choose M here.  The module
           will be called sun4i-emac.
 
+config SUN8I_EMAC
+	tristate "Allwinner sun8i EMAC support"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on OF
+	select MII
+	select PHYLIB
+        ---help---
+	  This driver support the sun8i EMAC ethernet driver present on
+	  H3/A83T/A64 Allwinner SoCs.
+
+          To compile this driver as a module, choose M here.  The module
+          will be called sun8i-emac.
+
 endif # NET_VENDOR_ALLWINNER
diff --git a/drivers/net/ethernet/allwinner/Makefile b/drivers/net/ethernet/allwinner/Makefile
index 03129f7..8bd1693c 100644
--- a/drivers/net/ethernet/allwinner/Makefile
+++ b/drivers/net/ethernet/allwinner/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_SUN4I_EMAC) += sun4i-emac.o
+obj-$(CONFIG_SUN8I_EMAC) += sun8i-emac.o
diff --git a/drivers/net/ethernet/allwinner/sun8i-emac.c b/drivers/net/ethernet/allwinner/sun8i-emac.c
new file mode 100644
index 0000000..1c4bc80
--- /dev/null
+++ b/drivers/net/ethernet/allwinner/sun8i-emac.c
@@ -0,0 +1,2255 @@
+/*
+ * sun8i-emac driver
+ *
+ * Copyright (C) 2015-2016 Corentin LABBE <clabbe.montjoie@xxxxxxxxx>
+ *
+ * This is the driver for Allwinner Ethernet MAC found in H3/A83T/A64 SoC
+ *
+ * TODO:
+ * - MAC filtering
+ * - Jumbo frame
+ * - features rx-all (NETIF_F_RXALL_BIT)
+ * - PM runtime
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/etherdevice.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/mii.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of_device.h>
+#include <linux/of_mdio.h>
+#include <linux/of_net.h>
+#include <linux/phy.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/scatterlist.h>
+#include <linux/skbuff.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#define EMAC_BASIC_CTL0	0x00
+#define EMAC_BASIC_CTL1	0x04
+#define EMAC_INT_STA	0x08
+#define EMAC_INT_EN	0x0C
+#define EMAC_TX_CTL0	0x10
+#define EMAC_TX_CTL1	0x14
+#define EMAC_TX_FLOW_CTL	0x1C
+#define EMAC_RX_CTL0	0x24
+#define EMAC_RX_CTL1	0x28
+#define EMAC_RX_FRM_FLT	0x38
+#define EMAC_MDIO_CMD	0x48
+#define EMAC_MDIO_DATA	0x4C
+#define EMAC_TX_DMA_STA	0xB0
+#define EMAC_TX_CUR_DESC	0xB4
+#define EMAC_TX_CUR_BUF	0xB8
+#define EMAC_RX_DMA_STA	0xC0
+
+#define MDIO_CMD_MII_BUSY	BIT(0)
+#define MDIO_CMD_MII_WRITE	BIT(1)
+#define MDIO_CMD_MII_PHY_REG_ADDR_MASK	GENMASK(8, 4)
+#define MDIO_CMD_MII_PHY_REG_ADDR_SHIFT	4
+#define MDIO_CMD_MII_PHY_ADDR_MASK	GENMASK(16, 12)
+#define MDIO_CMD_MII_PHY_ADDR_SHIFT	12
+
+#define EMAC_MACADDR_HI	0x50
+#define EMAC_MACADDR_LO	0x54
+
+#define EMAC_RX_DESC_LIST 0x34
+#define EMAC_TX_DESC_LIST 0x20
+
+#define EMAC_RX_DO_CRC BIT(27)
+#define EMAC_RX_STRIP_FCS BIT(28)
+
+#define LE32_BIT(x) (cpu_to_le32(BIT(x)))
+
+#define EMAC_COULD_BE_USED_BY_DMA LE32_BIT(31)
+
+/* Used in RX_CTL1*/
+#define EMAC_RX_DMA_EN	BIT(30)
+#define EMAC_RX_DMA_START	BIT(31)
+/* Used in TX_CTL1*/
+#define EMAC_TX_DMA_EN	BIT(30)
+#define EMAC_TX_DMA_START	BIT(31)
+
+/* Used in RX_CTL0 */
+#define EMAC_RX_RECEIVER_EN		BIT(31)
+/* Used in TX_CTL0 */
+#define EMAC_TX_TRANSMITTER_EN	BIT(31)
+
+/* Basic CTL0 */
+#define EMAC_BCTL0_FD BIT(0)
+#define EMAC_BCTL0_SPEED_10		2
+#define EMAC_BCTL0_SPEED_100		3
+#define EMAC_BCTL0_SPEED_MASK	GENMASK(3, 2)
+#define EMAC_BCTL0_SPEED_SHIFT	2
+
+#define EMAC_FLOW_RX 1
+#define EMAC_FLOW_TX 2
+
+#define EMAC_TX_INT		BIT(0)
+#define EMAC_TX_DMA_STOP_INT	BIT(1)
+#define EMAC_TX_BUF_UA_INT	BIT(2)
+#define EMAC_TX_TIMEOUT_INT	BIT(3)
+#define EMAC_TX_UNDERFLOW_INT	BIT(4)
+#define EMAC_TX_EARLY_INT	BIT(5)
+#define EMAC_RX_INT		BIT(8)
+#define EMAC_RX_BUF_UA_INT	BIT(9)
+#define EMAC_RX_DMA_STOP_INT	BIT(10)
+#define EMAC_RX_TIMEOUT_INT	BIT(11)
+#define EMAC_RX_OVERFLOW_INT	BIT(12)
+#define EMAC_RX_EARLY_INT	BIT(13)
+#define EMAC_RGMII_STA_INT	BIT(16)
+
+/* Bits used in frame RX status */
+#define EMAC_DSC_RX_FIRST		BIT(9)
+#define EMAC_DSC_RX_LAST		BIT(8)
+
+/* Bits used in frame TX ctl */
+#define EMAC_MAGIC_TX_BIT		LE32_BIT(24)
+#define EMAC_TX_DO_CRC		(LE32_BIT(27) | LE32_BIT(28))
+#define EMAC_DSC_TX_FIRST		LE32_BIT(29)
+#define EMAC_DSC_TX_LAST		LE32_BIT(30)
+#define EMAC_WANT_INT			LE32_BIT(31)
+
+/* struct emac_variant - Describe an emac variant of sun8i-emac
+ * @default_syscon_value: Default value of the syscon EMAC register
+ * The default_syscon_value is also used for powering down the PHY
+ * @internal_phy:	which PHY type is internal
+ * @support_mii:	Does the SoC support MII
+ * @support_rmii:	Does the SoC support RMII
+ * @support_rgmii:	Does the SoC support RGMII
+ */
+struct emac_variant {
+	u32 default_syscon_value;
+	int internal_phy;
+	bool support_mii;
+	bool support_rmii;
+	bool support_rgmii;
+};
+
+static const struct emac_variant emac_variant_h3 = {
+	.default_syscon_value = 0x58000,
+	.internal_phy = PHY_INTERFACE_MODE_MII,
+	.support_mii = true,
+	.support_rmii = true,
+	.support_rgmii = true
+};
+
+static const struct emac_variant emac_variant_a83t = {
+	.default_syscon_value = 0,
+	.internal_phy = 0,
+	.support_mii = true,
+	.support_rgmii = true
+};
+
+static const struct emac_variant emac_variant_a64 = {
+	.default_syscon_value = 0,
+	.internal_phy = 0,
+	.support_mii = true,
+	.support_rmii = true,
+	.support_rgmii = true
+};
+
+static const char const estats_str[][ETH_GSTRING_LEN] = {
+	/* errors */
+	"rx_payload_error",
+	"rx_CRC_error",
+	"rx_phy_error",
+	"rx_length_error",
+	"rx_col_error",
+	"rx_header_error",
+	"rx_overflow_error",
+	"rx_saf_error",
+	"rx_daf_error",
+	"rx_buf_error",
+	"rx_invalid_error",
+	"tx_timeout",
+	/* misc infos */
+	"tx_stop_queue",
+	"rx_dma_ua",
+	"rx_dma_stop",
+	"tx_dma_ua",
+	"tx_dma_stop",
+	"rx_hw_csum",
+	"tx_hw_csum",
+	/* interrupts */
+	"rx_int",
+	"tx_int",
+	"tx_early_int",
+	"tx_underflow_int",
+	"tx_timeout_int",
+	"rx_early_int",
+	"rx_overflow_int",
+	"rx_timeout_int",
+	"rgmii_state_int",
+	/* debug */
+	"tx_used_desc",
+	"napi_schedule",
+	"napi_underflow",
+};
+
+struct sun8i_emac_stats {
+	u64 rx_payload_error;
+	u64 rx_crc_error;
+	u64 rx_phy_error;
+	u64 rx_length_error;
+	u64 rx_col_error;
+	u64 rx_header_error;
+	u64 rx_overflow_error;
+	u64 rx_saf_fail;
+	u64 rx_daf_fail;
+	u64 rx_buf_error;
+	u64 rx_invalid_error;
+	u64 tx_timeout;
+
+	u64 tx_stop_queue;
+	u64 rx_dma_ua;
+	u64 rx_dma_stop;
+	u64 tx_dma_ua;
+	u64 tx_dma_stop;
+	u64 rx_hw_csum;
+	u64 tx_hw_csum;
+
+	u64 rx_int;
+	u64 tx_int;
+	u64 tx_early_int;
+	u64 tx_underflow_int;
+	u64 tx_timeout_int;
+	u64 rx_early_int;
+	u64 rx_overflow_int;
+	u64 rx_timeout_int;
+	u64 rgmii_state_int;
+
+	u64 tx_used_desc;
+	u64 napi_schedule;
+	u64 napi_underflow;
+};
+
+/* The datasheet said that each descriptor can transfers up to 4096bytes
+ * But latter, a register documentation reduce that value to 2048
+ * Anyway using 2048 cause strange behaviours and even BSP driver use 2047
+ */
+#define DESC_BUF_MAX 2044
+
+/* MAGIC value for knowing if a descriptor is available or not */
+#define DCLEAN cpu_to_le32(BIT(16) | BIT(14) | BIT(12) | BIT(10) | BIT(9))
+
+/* struct dma_desc - Structure of DMA descriptor used by the hardware
+ * @status:	Status of the frame written by HW, so RO for the
+ *		driver (except for BIT(31) which is R/W)
+ * @ctl:	Information on the frame written by the driver (INT, len,...)
+ * @buf_addr:	physical address of the frame data
+ * @next:	physical address of next dma_desc
+ */
+struct dma_desc {
+	__le32 status;
+	__le32 ctl;
+	__le32 buf_addr;
+	__le32 next;
+};
+
+/* Describe how data from skb are DMA mapped (used in txinfo map member) */
+#define MAP_SINGLE 1
+#define MAP_PAGE 2
+
+/* Structure for storing information about data in TX ring buffer */
+struct txinfo {
+	struct sk_buff *skb;
+	int map;
+};
+
+struct sun8i_emac_priv {
+	void __iomem *base;
+	struct regmap *regmap;
+	int irq;
+	struct device *dev;
+	struct net_device *ndev;
+	struct mii_bus *mdio;
+	struct napi_struct napi;
+	spinlock_t tx_lock;/* control the access of transmit descriptors */
+	int duplex;
+	int speed;
+	int link;
+	int phy_interface;
+	const struct emac_variant *variant;
+	struct device_node *phy_node;
+	struct clk *ahb_clk;
+	struct clk *ephy_clk;
+	bool use_internal_phy;
+
+	struct reset_control *rst_mac;
+	struct reset_control *rst_ephy;
+
+	struct dma_desc *dd_rx;
+	dma_addr_t dd_rx_phy;
+	struct dma_desc *dd_tx;
+	dma_addr_t dd_tx_phy;
+	struct sk_buff **rx_skb;
+	struct txinfo *txl;
+
+	int nbdesc_tx;
+	int nbdesc_rx;
+	int tx_slot;
+	int tx_dirty;
+	int rx_dirty;
+	struct sun8i_emac_stats estats;
+	u32 msg_enable;
+	int flow_ctrl;
+	int pause;
+};
+
+static irqreturn_t sun8i_emac_dma_interrupt(int irq, void *dev_id);
+
+static void rb_inc(int *p, const int max)
+{
+	(*p)++;
+	(*p) %= max;
+}
+
+/* Locking strategy:
+ * RX queue does not need any lock since only sun8i_emac_poll() access it.
+ * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and so
+ * sun8i_emac_poll())
+ * TX queue is handled by sun8i_emac_xmit(), sun8i_emac_complete_xmit() and
+ * sun8i_emac_tx_timeout()
+ * (All other RX modifiers (ringparam/ndo_stop) disable NAPI and stop queue)
+ *
+ * sun8i_emac_xmit() could fire only once (netif_tx_lock)
+ * sun8i_emac_complete_xmit() could fire only once (called from NAPI)
+ * sun8i_emac_tx_timeout() could fire only once (netif_tx_lock) and could not
+ * race with sun8i_emac_xmit (due to netif_tx_lock) and with
+ * sun8i_emac_complete_xmit which disable NAPI.
+ *
+ * So only sun8i_emac_xmit and sun8i_emac_complete_xmit could fire at the same
+ * time.
+ * But they never could modify the same descriptors:
+ * - sun8i_emac_complete_xmit() will modify only descriptors with empty status
+ * - sun8i_emac_xmit() will modify only descriptors set to DCLEAN
+ * Proper memory barriers ensure that descriptor set to DCLEAN could not be
+ * modified latter by sun8i_emac_complete_xmit().
+ */
+
+/* Return the number of contiguous free descriptors
+ * starting from tx_slot
+ */
+static int rb_tx_numfreedesc(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	if (priv->tx_slot < priv->tx_dirty)
+		return priv->tx_dirty - priv->tx_slot;
+
+	return (priv->nbdesc_tx - priv->tx_slot) + priv->tx_dirty;
+}
+
+/* sun8i_emac_rx_skb - Allocate a skb in a DMA descriptor
+ *
+ * @ndev:	The net_device for this interface
+ * @i:		index of slot to fill
+ *
+ * Refill a DMA descriptor with a fresh skb and map it for DMA.
+*/
+static int sun8i_emac_rx_skb(struct net_device *ndev, int i)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct dma_desc *ddesc;
+	struct sk_buff *skb;
+
+	ddesc = priv->dd_rx + i;
+
+	ddesc->ctl = 0;
+
+	skb = netdev_alloc_skb_ip_align(ndev, DESC_BUF_MAX);
+	if (!skb)
+		return -ENOMEM;
+
+	/* should not happen */
+	if (unlikely(priv->rx_skb[i]))
+		dev_warn(priv->dev, "BUG: Leaking a skbuff\n");
+
+	priv->rx_skb[i] = skb;
+
+	ddesc->buf_addr = dma_map_single(priv->dev, skb->data,
+					 DESC_BUF_MAX, DMA_FROM_DEVICE);
+	if (dma_mapping_error(priv->dev, ddesc->buf_addr)) {
+		dev_err(priv->dev, "ERROR: Cannot map RX buffer for DMA\n");
+		dev_kfree_skb(skb);
+		return -EFAULT;
+	}
+	/* We cannot direcly use cpu_to_le32() after dma_map_single
+	 * since dma_mapping_error use it
+	 */
+	ddesc->buf_addr = cpu_to_le32(ddesc->buf_addr);
+	ddesc->ctl |= cpu_to_le32(DESC_BUF_MAX);
+	/* EMAC_COULD_BE_USED_BY_DMA must be the last value written */
+	wmb();
+	ddesc->status = EMAC_COULD_BE_USED_BY_DMA;
+
+	return 0;
+}
+
+static void sun8i_emac_stop_tx(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v;
+
+	netif_stop_queue(ndev);
+
+	v = readl(priv->base + EMAC_TX_CTL0);
+	/* Disable transmitter after current reception */
+	v &= ~EMAC_TX_TRANSMITTER_EN;
+	writel(v, priv->base + EMAC_TX_CTL0);
+
+	v = readl(priv->base + EMAC_TX_CTL1);
+	/* Stop TX DMA */
+	v &= ~EMAC_TX_DMA_EN;
+	writel(v, priv->base + EMAC_TX_CTL1);
+
+	/* We must be sure that all is stopped before leaving this function */
+	wmb();
+}
+
+static void sun8i_emac_stop_rx(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v;
+
+	v = readl(priv->base + EMAC_RX_CTL0);
+	/* Disable receiver after current reception */
+	v &= ~EMAC_RX_RECEIVER_EN;
+	writel(v, priv->base + EMAC_RX_CTL0);
+
+	v = readl(priv->base + EMAC_RX_CTL1);
+	/* Stop RX DMA */
+	v &= ~EMAC_RX_DMA_EN;
+	writel(v, priv->base + EMAC_RX_CTL1);
+
+	/* We must be sure that all is stopped before leaving this function */
+	wmb();
+}
+
+static void sun8i_emac_start_rx(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v;
+
+	v = readl(priv->base + EMAC_RX_CTL0);
+	/* Enable receiver */
+	v |= EMAC_RX_RECEIVER_EN;
+	writel(v, priv->base + EMAC_RX_CTL0);
+
+	v = readl(priv->base + EMAC_RX_CTL1);
+	v |= EMAC_RX_DMA_START;
+	v |= EMAC_RX_DMA_EN;
+	writel(v, priv->base + EMAC_RX_CTL1);
+}
+
+static void sun8i_emac_start_tx(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v;
+
+	v = readl(priv->base + EMAC_TX_CTL0);
+	v |= EMAC_TX_TRANSMITTER_EN;
+	writel(v, priv->base + EMAC_TX_CTL0);
+
+	v = readl(priv->base + EMAC_TX_CTL1);
+	v |= EMAC_TX_DMA_START;
+	v |= EMAC_TX_DMA_EN;
+	writel(v, priv->base + EMAC_TX_CTL1);
+}
+
+/* sun8i_emac_set_macaddr - Set MAC address for slot index
+ *
+ * @addr: the MAC address to set
+ * @index: The index of slot where to set address.
+ *
+ * The slot 0 is the main MAC address
+ */
+static void sun8i_emac_set_macaddr(struct sun8i_emac_priv *priv,
+				   const u8 *addr, int index)
+{
+	u32 v;
+
+	dev_info(priv->dev, "device MAC address slot %d %pM", index, addr);
+
+	v = (addr[5] << 8) | addr[4];
+	writel(v, priv->base + EMAC_MACADDR_HI + index * 8);
+
+	v = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
+	writel(v, priv->base + EMAC_MACADDR_LO + index * 8);
+}
+
+static void sun8i_emac_set_link_mode(struct sun8i_emac_priv *priv)
+{
+	u32 v;
+
+	v = readl(priv->base + EMAC_BASIC_CTL0);
+
+	if (priv->duplex)
+		v |= EMAC_BCTL0_FD;
+	else
+		v &= ~EMAC_BCTL0_FD;
+
+	v &= ~EMAC_BCTL0_SPEED_MASK;
+
+	switch (priv->speed) {
+	case 1000:
+		break;
+	case 100:
+		v |= EMAC_BCTL0_SPEED_100 << EMAC_BCTL0_SPEED_SHIFT;
+		break;
+	case 10:
+		v |= EMAC_BCTL0_SPEED_10 << EMAC_BCTL0_SPEED_SHIFT;
+		break;
+	default:
+		dev_err(priv->dev, "Unsupported speed %d\n", priv->speed);
+		return;
+	}
+
+	writel(v, priv->base + EMAC_BASIC_CTL0);
+}
+
+static void sun8i_emac_flow_ctrl(struct sun8i_emac_priv *priv, int duplex,
+				 int fc)
+{
+	u32 flow = 0;
+
+	flow = readl(priv->base + EMAC_RX_CTL0);
+	if (fc & EMAC_FLOW_RX)
+		flow |= BIT(16);
+	else
+		flow &= ~BIT(16);
+	writel(flow, priv->base + EMAC_RX_CTL0);
+
+	flow = readl(priv->base + EMAC_TX_FLOW_CTL);
+	if (fc & EMAC_FLOW_TX)
+		flow |= BIT(0);
+	else
+		flow &= ~BIT(0);
+	writel(flow, priv->base + EMAC_TX_FLOW_CTL);
+}
+
+/* Grab a frame into a skb from descriptor number i */
+static int sun8i_emac_rx_from_ddesc(struct net_device *ndev, int i)
+{
+	struct sk_buff *skb;
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct dma_desc *ddesc = priv->dd_rx + i;
+	int frame_len;
+	int rxcsum_done = 0;
+	u32 dstatus = le32_to_cpu(ddesc->status);
+
+	if (ndev->features & NETIF_F_RXCSUM)
+		rxcsum_done = 1;
+
+	/* bit0/bit7 work only on IPv4/IPv6 TCP traffic,
+	 * (not on ARP for example) so we do not raise rx_errors/discard frame
+	 */
+	/* the checksum or length of received frame's payload is wrong*/
+	if (dstatus & BIT(0)) {
+		priv->estats.rx_payload_error++;
+		rxcsum_done = 0;
+	}
+
+	/* RX_CRC_ERR */
+	if (dstatus & BIT(1)) {
+		priv->ndev->stats.rx_errors++;
+		priv->ndev->stats.rx_crc_errors++;
+		priv->estats.rx_crc_error++;
+		goto discard_frame;
+	}
+
+	/* RX_PHY_ERR */
+	if ((dstatus & BIT(3))) {
+		priv->ndev->stats.rx_errors++;
+		priv->estats.rx_phy_error++;
+		goto discard_frame;
+	}
+
+	/* RX_LENGTH_ERR */
+	if ((dstatus & BIT(4))) {
+		priv->ndev->stats.rx_errors++;
+		priv->ndev->stats.rx_length_errors++;
+		priv->estats.rx_length_error++;
+		goto discard_frame;
+	}
+
+	/* RX_COL_ERR */
+	if ((dstatus & BIT(6))) {
+		priv->ndev->stats.rx_errors++;
+		priv->estats.rx_col_error++;
+		goto discard_frame;
+	}
+
+	/* RX_HEADER_ERR */
+	if ((dstatus & BIT(7))) {
+		priv->estats.rx_header_error++;
+		rxcsum_done = 0;
+	}
+
+	/* RX_OVERFLOW_ERR */
+	if ((dstatus & BIT(11))) {
+		priv->ndev->stats.rx_over_errors++;
+		priv->estats.rx_overflow_error++;
+		goto discard_frame;
+	}
+
+	/* RX_NO_ENOUGTH_BUF_ERR */
+	if ((dstatus & BIT(14))) {
+		priv->ndev->stats.rx_errors++;
+		priv->estats.rx_buf_error++;
+		goto discard_frame;
+	}
+
+	/* BIT(9) is for the first frame, not having it is bad since we do not
+	 * handle Jumbo frame
+	 */
+	if ((dstatus & EMAC_DSC_RX_FIRST) == 0) {
+		priv->ndev->stats.rx_errors++;
+		priv->estats.rx_invalid_error++;
+		goto discard_frame;
+	}
+
+	/* this frame is not the last */
+	if ((dstatus & EMAC_DSC_RX_LAST) == 0) {
+		priv->ndev->stats.rx_errors++;
+		priv->estats.rx_invalid_error++;
+		goto discard_frame;
+	}
+
+	frame_len = (dstatus >> 16) & 0x3FFF;
+	if (!(ndev->features & NETIF_F_RXFCS))
+		frame_len -= ETH_FCS_LEN;
+
+	skb = priv->rx_skb[i];
+
+	netif_dbg(priv, rx_status, priv->ndev,
+		  "%s from %02d %pad len=%d status=%x st=%x\n",
+		  __func__, i, &ddesc, frame_len, dstatus,
+		  cpu_to_le32(ddesc->ctl));
+
+	skb_put(skb, frame_len);
+
+	dma_unmap_single(priv->dev, le32_to_cpu(ddesc->buf_addr), DESC_BUF_MAX,
+			 DMA_FROM_DEVICE);
+	skb->protocol = eth_type_trans(skb, priv->ndev);
+	if (rxcsum_done) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		priv->estats.rx_hw_csum++;
+	} else {
+		skb->ip_summed = CHECKSUM_PARTIAL;
+	}
+
+	priv->ndev->stats.rx_packets++;
+	priv->ndev->stats.rx_bytes += frame_len;
+	priv->rx_skb[i] = NULL;
+
+	sun8i_emac_rx_skb(ndev, i);
+	napi_gro_receive(&priv->napi, skb);
+
+	return 0;
+	/* If the frame need to be dropped, we simply reuse the buffer */
+discard_frame:
+	ddesc->ctl = cpu_to_le32(DESC_BUF_MAX);
+	/* EMAC_COULD_BE_USED_BY_DMA must be the last value written */
+	wmb();
+	ddesc->status = EMAC_COULD_BE_USED_BY_DMA;
+	return 0;
+}
+
+/* Iterate over dma_desc for finding completed xmit.
+ *
+ * The problem is: how to know that a descriptor is sent and not just in
+ * preparation.
+ * Need to have status=0 and st set but this is the state of first frame just
+ * before setting the own-by-DMA bit.
+ * The solution is to used the artificial value DCLEAN.
+ */
+static int sun8i_emac_complete_xmit(struct net_device *ndev, int budget)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct dma_desc *ddesc;
+	int frame_len;
+	int work = 0;
+	unsigned int bytes_compl = 0, pkts_compl = 0;
+	u32 dstatus;
+
+	do {
+		ddesc = priv->dd_tx + priv->tx_dirty;
+
+		if (ddesc->status & EMAC_COULD_BE_USED_BY_DMA)
+			goto xmit_end;
+
+		if (ddesc->status == DCLEAN)
+			goto xmit_end;
+
+		dstatus = cpu_to_le32(ddesc->status);
+
+		if (ddesc->status == 0 && !ddesc->ctl) {
+			dev_err(priv->dev, "BUG: reached the void %d %d\n",
+				priv->tx_dirty, priv->tx_slot);
+			goto xmit_end;
+		}
+
+		/* TX_UNDERFLOW_ERR */
+		if (dstatus & BIT(1))
+			priv->ndev->stats.tx_errors++;
+		/* TX_DEFER_ERR */
+		if (dstatus & BIT(2))
+			priv->ndev->stats.tx_errors++;
+		/* BIT 6:3 numbers of collisions */
+		if (dstatus & 0x78)
+			priv->ndev->stats.collisions +=
+				(dstatus & 0x78) >> 3;
+		/* TX_COL_ERR_1 */
+		if (dstatus & BIT(8))
+			priv->ndev->stats.tx_errors++;
+		/* TX_COL_ERR_0 */
+		if (dstatus & BIT(9))
+			priv->ndev->stats.tx_errors++;
+		/* TX_CRS_ERR */
+		if (dstatus & BIT(10))
+			priv->ndev->stats.tx_carrier_errors++;
+		/* TX_PAYLOAD_ERR */
+		if (dstatus & BIT(12))
+			priv->ndev->stats.tx_errors++;
+		/* TX_LENGTH_ERR */
+		if (dstatus & BIT(14))
+			priv->ndev->stats.tx_errors++;
+		/* TX_HEADER_ERR */
+		if (dstatus & BIT(16))
+			priv->ndev->stats.tx_errors++;
+
+		frame_len = le32_to_cpu(ddesc->ctl) & 0x3FFF;
+		bytes_compl += frame_len;
+
+		if (priv->txl[priv->tx_dirty].map == MAP_SINGLE)
+			dma_unmap_single(priv->dev,
+					 le32_to_cpu(ddesc->buf_addr),
+					 frame_len, DMA_TO_DEVICE);
+		else
+			dma_unmap_page(priv->dev,
+				       le32_to_cpu(ddesc->buf_addr),
+				       frame_len, DMA_TO_DEVICE);
+		/* we can free skb only on last frame */
+		if (priv->txl[priv->tx_dirty].skb &&
+		    (ddesc->ctl & EMAC_DSC_TX_LAST)) {
+			dev_kfree_skb_irq(priv->txl[priv->tx_dirty].skb);
+			pkts_compl++;
+		}
+
+		priv->txl[priv->tx_dirty].skb = NULL;
+		priv->txl[priv->tx_dirty].map = 0;
+		ddesc->ctl = 0;
+		/* setting status to DCLEAN is the last value to be set */
+		wmb();
+		ddesc->status = DCLEAN;
+		work++;
+
+		rb_inc(&priv->tx_dirty, priv->nbdesc_tx);
+		ddesc = priv->dd_tx + priv->tx_dirty;
+	} while (ddesc->ctl &&
+		 !(ddesc->status & EMAC_COULD_BE_USED_BY_DMA) &&
+		 work < budget);
+
+xmit_end:
+	netdev_completed_queue(ndev, pkts_compl, bytes_compl);
+
+	/* if we don't have handled all packets */
+	if (work < budget)
+		work = 0;
+
+	if (netif_queue_stopped(ndev) &&
+	    rb_tx_numfreedesc(ndev) > MAX_SKB_FRAGS + 1)
+		netif_wake_queue(ndev);
+	return work;
+}
+
+static int sun8i_emac_poll(struct napi_struct *napi, int budget)
+{
+	struct sun8i_emac_priv *priv =
+		container_of(napi, struct sun8i_emac_priv, napi);
+	struct net_device *ndev = priv->ndev;
+	int worked;
+	struct dma_desc *ddesc;
+
+	priv->estats.napi_schedule++;
+	worked = sun8i_emac_complete_xmit(ndev, budget);
+
+	ddesc = priv->dd_rx + priv->rx_dirty;
+	while (!(ddesc->status & EMAC_COULD_BE_USED_BY_DMA) &&
+	       worked < budget) {
+		sun8i_emac_rx_from_ddesc(ndev, priv->rx_dirty);
+		worked++;
+		rb_inc(&priv->rx_dirty, priv->nbdesc_rx);
+		ddesc = priv->dd_rx + priv->rx_dirty;
+	};
+	if (worked < budget) {
+		priv->estats.napi_underflow++;
+		napi_complete(&priv->napi);
+		writel(EMAC_RX_INT | EMAC_TX_INT, priv->base + EMAC_INT_EN);
+	}
+	return worked;
+}
+
+static int sun8i_mdio_read(struct mii_bus *bus, int phy_addr, int phy_reg)
+{
+	struct net_device *ndev = bus->priv;
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int err;
+	u32 reg;
+
+	err = readl_poll_timeout(priv->base + EMAC_MDIO_CMD, reg,
+				 !(reg & MDIO_CMD_MII_BUSY), 100, 10000);
+	if (err) {
+		dev_err(priv->dev, "%s timeout %x\n", __func__, reg);
+		return err;
+	}
+
+	reg &= ~MDIO_CMD_MII_WRITE;
+	reg &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
+	reg |= (phy_reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
+		MDIO_CMD_MII_PHY_REG_ADDR_MASK;
+
+	reg &= ~MDIO_CMD_MII_PHY_ADDR_MASK;
+
+	reg |= (phy_addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
+		MDIO_CMD_MII_PHY_ADDR_MASK;
+
+	reg |= MDIO_CMD_MII_BUSY;
+
+	writel(reg, priv->base + EMAC_MDIO_CMD);
+
+	err = readl_poll_timeout(priv->base + EMAC_MDIO_CMD, reg,
+				 !(reg & MDIO_CMD_MII_BUSY), 100, 10000);
+
+	if (err) {
+		dev_err(priv->dev, "%s timeout %x\n", __func__, reg);
+		return err;
+	}
+
+	return readl(priv->base + EMAC_MDIO_DATA);
+}
+
+static int sun8i_mdio_write(struct mii_bus *bus, int phy_addr, int phy_reg,
+			    u16 data)
+{
+	struct net_device *ndev = bus->priv;
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 reg;
+	int err;
+
+	err = readl_poll_timeout(priv->base + EMAC_MDIO_CMD, reg,
+				 !(reg & MDIO_CMD_MII_BUSY), 100, 10000);
+	if (err) {
+		dev_err(priv->dev, "%s timeout %x\n", __func__, reg);
+		return err;
+	}
+
+	reg &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
+	reg |= (phy_reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
+		MDIO_CMD_MII_PHY_REG_ADDR_MASK;
+
+	reg &= ~MDIO_CMD_MII_PHY_ADDR_MASK;
+	reg |= (phy_addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
+		MDIO_CMD_MII_PHY_ADDR_MASK;
+
+	reg |= MDIO_CMD_MII_WRITE;
+	reg |= MDIO_CMD_MII_BUSY;
+
+	writel(reg, priv->base + EMAC_MDIO_CMD);
+	writel(data, priv->base + EMAC_MDIO_DATA);
+
+	err = readl_poll_timeout(priv->base + EMAC_MDIO_CMD, reg,
+				 !(reg & MDIO_CMD_MII_BUSY), 100, 10000);
+	if (err) {
+		dev_err(priv->dev, "%s timeout %x\n", __func__, reg);
+		return err;
+	}
+
+	return 0;
+}
+
+static int sun8i_emac_mdio_register(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct mii_bus *bus;
+	int ret;
+
+	bus = mdiobus_alloc();
+	if (!bus) {
+		netdev_err(ndev, "Failed to allocate a new mdio bus\n");
+		return -ENOMEM;
+	}
+
+	bus->name = dev_name(priv->dev);
+	bus->read = &sun8i_mdio_read;
+	bus->write = &sun8i_mdio_write;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%x", bus->name, priv->dev->id);
+
+	bus->parent = priv->dev;
+	bus->priv = ndev;
+
+	ret = of_mdiobus_register(bus, priv->dev->of_node);
+	if (ret) {
+		netdev_err(ndev, "Could not register a MDIO bus: %d\n", ret);
+		mdiobus_free(bus);
+		return ret;
+	}
+
+	priv->mdio = bus;
+
+	return 0;
+}
+
+static void sun8i_emac_mdio_unregister(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	mdiobus_unregister(priv->mdio);
+	mdiobus_free(priv->mdio);
+}
+
+/* Run within phydev->lock */
+static void sun8i_emac_adjust_link(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct phy_device *phydev = ndev->phydev;
+	int new_state = 0;
+
+	netif_dbg(priv, link, priv->ndev,
+		  "%s link=%x duplex=%x speed=%x\n", __func__,
+		  phydev->link, phydev->duplex, phydev->speed);
+	if (!phydev)
+		return;
+
+	if (phydev->link) {
+		if (phydev->duplex != priv->duplex) {
+			new_state = 1;
+			priv->duplex = phydev->duplex;
+		}
+		if (phydev->pause)
+			sun8i_emac_flow_ctrl(priv, phydev->duplex,
+					     priv->flow_ctrl);
+
+		if (phydev->speed != priv->speed) {
+			new_state = 1;
+			priv->speed = phydev->speed;
+		}
+
+		if (priv->link == 0) {
+			new_state = 1;
+			priv->link = phydev->link;
+		}
+
+		netif_dbg(priv, link, priv->ndev,
+			  "%s new=%d link=%d pause=%d\n",
+			  __func__, new_state, priv->link, phydev->pause);
+		if (new_state)
+			sun8i_emac_set_link_mode(priv);
+	} else if (priv->link != phydev->link) {
+		new_state = 1;
+		priv->link = 0;
+		priv->speed = 0;
+		priv->duplex = -1;
+	}
+
+	if (new_state)
+		phy_print_status(phydev);
+}
+
+/* H3 specific bits for EPHY */
+#define H3_EPHY_ADDR_SHIFT	20
+#define H3_EPHY_LED_POL		BIT(17) /* 1: active low, 0: active high */
+#define H3_EPHY_SHUTDOWN	BIT(16) /* 1: shutdown, 0: power up */
+#define H3_EPHY_SELECT		BIT(15) /* 1: internal PHY, 0: external PHY */
+
+/* H3/A64 specific bits */
+#define SYSCON_RMII_EN		BIT(13) /* 1: enable RMII (overrides EPIT) */
+
+/* Generic system control EMAC_CLK bits */
+#define SYSCON_ETXDC_MASK		GENMASK(2, 0)
+#define SYSCON_ETXDC_SHIFT		10
+#define SYSCON_ERXDC_MASK		GENMASK(4, 0)
+#define SYSCON_ERXDC_SHIFT		5
+/* EMAC PHY Interface Type */
+#define SYSCON_EPIT			BIT(2) /* 1: RGMII, 0: MII */
+#define SYSCON_ETCS_MASK		GENMASK(1, 0)
+#define SYSCON_ETCS_MII		0x0
+#define SYSCON_ETCS_EXT_GMII	0x1
+#define SYSCON_ETCS_INT_GMII	0x2
+#define SYSCON_EMAC_REG		0x30
+
+static int sun8i_emac_set_syscon(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct device_node *node = priv->dev->of_node;
+	int ret;
+	u32 reg, val;
+
+	reg = priv->variant->default_syscon_value;
+
+	if (priv->variant->internal_phy) {
+		if (!priv->use_internal_phy) {
+			/* switch to external PHY interface */
+			reg &= ~H3_EPHY_SELECT;
+		} else {
+			reg |= H3_EPHY_SELECT;
+			reg &= ~H3_EPHY_SHUTDOWN;
+
+			if (of_property_read_bool(priv->phy_node,
+						  "allwinner,leds-active-low"))
+				reg |= H3_EPHY_LED_POL;
+
+			ret = of_mdio_parse_addr(priv->dev, priv->phy_node);
+			if (ret < 0) {
+				netdev_err(ndev, "Could not parse MDIO addr\n");
+				return ret;
+			}
+			/* of_mdio_parse_addr returns a valid (0 ~ 31) PHY
+			 * address. No need to mask it again.
+			 */
+			reg |= ret << H3_EPHY_ADDR_SHIFT;
+		}
+	}
+
+	if (!of_property_read_u32(node, "allwinner,tx-delay", &val)) {
+		if (val <= SYSCON_ETXDC_MASK) {
+			reg &= ~(SYSCON_ETXDC_MASK << SYSCON_ETXDC_SHIFT);
+			reg |= (val << SYSCON_ETXDC_SHIFT);
+		} else {
+			netdev_warn(ndev, "Invalid TX clock delay: %d\n", val);
+		}
+	}
+
+	if (!of_property_read_u32(node, "allwinner,rx-delay", &val)) {
+		if (val <= SYSCON_ERXDC_MASK) {
+			reg &= ~(SYSCON_ERXDC_MASK << SYSCON_ERXDC_SHIFT);
+			reg |= (val << SYSCON_ERXDC_SHIFT);
+		} else {
+			netdev_warn(ndev, "Invalid RX clock delay: %d\n", val);
+		}
+	}
+
+	/* Clear interface mode bits */
+	reg &= ~(SYSCON_ETCS_MASK | SYSCON_EPIT);
+	if (priv->variant->support_rmii)
+		reg &= ~SYSCON_RMII_EN;
+
+	switch (priv->phy_interface) {
+	case PHY_INTERFACE_MODE_MII:
+		/* default */
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+		reg |= SYSCON_EPIT | SYSCON_ETCS_INT_GMII;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		reg |= SYSCON_RMII_EN | SYSCON_ETCS_EXT_GMII;
+		break;
+	default:
+		netdev_err(ndev, "Unsupported interface mode: %s",
+			   phy_modes(priv->phy_interface));
+		return -EINVAL;
+	}
+
+	regmap_write(priv->regmap, SYSCON_EMAC_REG, reg);
+
+	return 0;
+}
+
+static void sun8i_emac_unset_syscon(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 reg = priv->variant->default_syscon_value;
+
+	regmap_write(priv->regmap, SYSCON_EMAC_REG, reg);
+}
+
+/* Set Management Data Clock, must be call after device reset */
+static void sun8i_emac_set_mdc(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	unsigned long rate;
+	u32 reg;
+
+	rate = clk_get_rate(priv->ahb_clk);
+	if (rate > 160000000)
+		reg = 0x3 << 20; /* AHB / 128 */
+	else if (rate > 80000000)
+		reg = 0x2 << 20; /* AHB / 64 */
+	else if (rate > 40000000)
+		reg = 0x1 << 20; /* AHB / 32 */
+	else
+		reg = 0x0 << 20; /* AHB / 16 */
+	netif_dbg(priv, link, ndev, "MDC auto : %x\n", reg);
+	writel(reg, priv->base + EMAC_MDIO_CMD);
+}
+
+/* "power" the device, by enabling clk/reset/regulators */
+static int sun8i_emac_power(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int ret;
+
+	ret = clk_prepare_enable(priv->ahb_clk);
+	if (ret) {
+		netdev_err(ndev, "Could not enable AHB clock\n");
+		return ret;
+	}
+
+	if (priv->rst_mac) {
+		ret = reset_control_deassert(priv->rst_mac);
+		if (ret) {
+			netdev_err(ndev, "Could not deassert reset\n");
+			goto err_reset;
+		}
+	}
+
+	if (priv->ephy_clk) {
+		ret = clk_prepare_enable(priv->ephy_clk);
+		if (ret) {
+			netdev_err(ndev, "Could not enable EPHY clock\n");
+			goto err_ephy_clk;
+		}
+	}
+
+	if (priv->rst_ephy) {
+		ret = reset_control_deassert(priv->rst_ephy);
+		if (ret) {
+			netdev_err(ndev, "Could not deassert EPHY reset\n");
+			goto err_ephy_reset;
+		}
+	}
+
+	return 0;
+
+err_ephy_reset:
+	if (priv->ephy_clk)
+		clk_disable_unprepare(priv->ephy_clk);
+err_ephy_clk:
+	if (priv->rst_mac)
+		reset_control_assert(priv->rst_mac);
+err_reset:
+	clk_disable_unprepare(priv->ahb_clk);
+	return ret;
+}
+
+/* "Unpower" the device, disabling clocks and regulators, asserting reset */
+static void sun8i_emac_unpower(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	if (priv->rst_ephy)
+		reset_control_assert(priv->rst_ephy);
+
+	if (priv->ephy_clk)
+		clk_disable_unprepare(priv->ephy_clk);
+
+	if (priv->rst_mac)
+		reset_control_assert(priv->rst_mac);
+
+	clk_disable_unprepare(priv->ahb_clk);
+}
+
+static int sun8i_emac_init(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct device_node *node = priv->dev->of_node;
+	const u8 *addr;
+
+	/* Try to get MAC address from DT, or assign a random one */
+	addr = of_get_mac_address(node);
+	if (addr)
+		ether_addr_copy(ndev->dev_addr, addr);
+	else
+		eth_hw_addr_random(ndev);
+
+	return sun8i_emac_power(ndev);
+}
+
+static void sun8i_emac_uninit(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	mdiobus_unregister(priv->mdio);
+
+	sun8i_emac_unpower(ndev);
+}
+
+static int sun8i_emac_mdio_probe(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct phy_device *phydev = NULL;
+
+	phydev = of_phy_connect(ndev, priv->phy_node, &sun8i_emac_adjust_link,
+				0, priv->phy_interface);
+
+	if (!phydev) {
+		netdev_err(ndev, "Could not attach to PHY\n");
+		return -ENODEV;
+	}
+
+	phy_attached_info(phydev);
+
+	/* mask with MAC supported features */
+	phydev->supported &= PHY_GBIT_FEATURES;
+	phydev->advertising = phydev->supported;
+
+	priv->link = 0;
+	priv->speed = 0;
+	priv->duplex = -1;
+
+	return 0;
+}
+
+/* Allocate both RX and TX ring buffer and init them
+ * This function also write the startbase of thoses ring in the device.
+ * All structures that help managing thoses rings are also handled
+ * by this functions (rx_skb/txl)
+ */
+static int sun8i_emac_alloc_rings(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct dma_desc *ddesc;
+	int err, i;
+
+	priv->rx_skb = kcalloc(priv->nbdesc_rx, sizeof(struct sk_buff *),
+			      GFP_KERNEL);
+	if (!priv->rx_skb) {
+		err = -ENOMEM;
+		goto rx_skb_error;
+	}
+	priv->txl = kcalloc(priv->nbdesc_tx, sizeof(struct txinfo), GFP_KERNEL);
+	if (!priv->txl) {
+		err = -ENOMEM;
+		goto tx_error;
+	}
+
+	/* allocate/init RX ring */
+	priv->dd_rx = dma_zalloc_coherent(priv->dev,
+			priv->nbdesc_rx * sizeof(struct dma_desc),
+			&priv->dd_rx_phy, GFP_KERNEL);
+	if (!priv->dd_rx) {
+		dev_err(priv->dev, "ERROR: cannot allocate DMA RX buffer");
+		err = -ENOMEM;
+		goto dma_rx_error;
+	}
+	ddesc = priv->dd_rx;
+	for (i = 0; i < priv->nbdesc_rx; i++) {
+		sun8i_emac_rx_skb(ndev, i);
+		ddesc->next = cpu_to_le32(priv->dd_rx_phy + (i + 1)
+			* sizeof(struct dma_desc));
+		ddesc++;
+	}
+	/* last descriptor point back to first one */
+	ddesc--;
+	ddesc->next = cpu_to_le32(priv->dd_rx_phy);
+
+	/* allocate/init TX ring */
+	priv->dd_tx = dma_zalloc_coherent(priv->dev,
+			priv->nbdesc_tx * sizeof(struct dma_desc),
+			&priv->dd_tx_phy, GFP_KERNEL);
+	if (!priv->dd_tx) {
+		dev_err(priv->dev, "ERROR: cannot allocate DMA TX buffer");
+		err = -ENOMEM;
+		goto dma_tx_error;
+	}
+	ddesc = priv->dd_tx;
+	for (i = 0; i < priv->nbdesc_tx; i++) {
+		ddesc->status = DCLEAN;
+		ddesc->ctl = 0;
+		ddesc->next = cpu_to_le32(priv->dd_tx_phy + (i + 1)
+			* sizeof(struct dma_desc));
+		ddesc++;
+	}
+	/* last descriptor point back to first one */
+	ddesc--;
+	ddesc->next = cpu_to_le32(priv->dd_tx_phy);
+	i--;
+
+	priv->tx_slot = 0;
+	priv->tx_dirty = 0;
+	priv->rx_dirty = 0;
+
+	/* write start of RX ring descriptor */
+	writel(priv->dd_rx_phy, priv->base + EMAC_RX_DESC_LIST);
+	/* write start of TX ring descriptor */
+	writel(priv->dd_tx_phy, priv->base + EMAC_TX_DESC_LIST);
+
+	return 0;
+dma_tx_error:
+	dma_free_coherent(priv->dev, priv->nbdesc_rx * sizeof(struct dma_desc),
+			  priv->dd_rx, priv->dd_rx_phy);
+dma_rx_error:
+	kfree(priv->txl);
+tx_error:
+	kfree(priv->rx_skb);
+rx_skb_error:
+	return err;
+}
+
+static int sun8i_emac_open(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int err;
+	u32 v;
+
+	err = request_irq(priv->irq, sun8i_emac_dma_interrupt, 0,
+			  dev_name(priv->dev), ndev);
+	if (err) {
+		dev_err(priv->dev, "Cannot request IRQ: %d\n", err);
+		return err;
+	}
+
+	/* Set interface mode (and configure internal PHY on H3) */
+	err = sun8i_emac_set_syscon(ndev);
+	if (err)
+		goto err_irq;
+
+	/* Do SOFT RST */
+	v = readl(priv->base + EMAC_BASIC_CTL1);
+	writel(v | 0x01, priv->base + EMAC_BASIC_CTL1);
+
+	err = readl_poll_timeout(priv->base + EMAC_BASIC_CTL1, v,
+				 !(v & 0x01), 100, 10000);
+	if (err) {
+		dev_err(priv->dev, "EMAC reset timeout\n");
+		err = -EFAULT;
+		goto err_syscon;
+	}
+
+	sun8i_emac_set_mdc(ndev);
+
+	err = sun8i_emac_mdio_register(ndev);
+	if (err)
+		goto err_syscon;
+
+	err = sun8i_emac_mdio_probe(ndev);
+	if (err)
+		goto err_syscon;
+
+	/* DMA */
+	v = (8 << 24);/* burst len */
+	writel(v, priv->base + EMAC_BASIC_CTL1);
+
+	writel(EMAC_RX_INT | EMAC_TX_INT, priv->base + EMAC_INT_EN);
+
+	v = readl(priv->base + EMAC_RX_CTL0);
+	/* CHECK_CRC */
+	if (ndev->features & NETIF_F_RXCSUM)
+		v |= EMAC_RX_DO_CRC;
+	else
+		v &= ~EMAC_RX_DO_CRC;
+	/* STRIP_FCS */
+	if (ndev->features & NETIF_F_RXFCS)
+		v &= ~EMAC_RX_STRIP_FCS;
+	else
+		v |= EMAC_RX_STRIP_FCS;
+	writel(v, priv->base + EMAC_RX_CTL0);
+
+	v = readl(priv->base + EMAC_TX_CTL1);
+	/* TX_MD Transmission starts after a full frame located in TX DMA FIFO*/
+	v |= BIT(1);
+	/* Undocumented bit (called TX_NEXT_FRM in BSP), the original comment is
+	 * "Operating on second frame increase the performance
+	 * especially when transmit store-and-forward is used."
+	 */
+	v |= BIT(2);
+	writel(v, priv->base + EMAC_TX_CTL1);
+
+	v = readl(priv->base + EMAC_RX_CTL1);
+	/* RX_MD RX DMA reads data from RX DMA FIFO to host memory after a
+	 * complete frame has been written to RX DMA FIFO
+	*/
+	v |= BIT(1);
+	writel(v, priv->base + EMAC_RX_CTL1);
+
+	sun8i_emac_set_macaddr(priv, ndev->dev_addr, 0);
+
+	err = sun8i_emac_alloc_rings(ndev);
+	if (err) {
+		netdev_err(ndev, "Fail to allocate rings\n");
+		goto err_mdio;
+	}
+
+	phy_start(ndev->phydev);
+
+	sun8i_emac_start_rx(ndev);
+	sun8i_emac_start_tx(ndev);
+
+	netif_napi_add(ndev, &priv->napi, sun8i_emac_poll, 64);
+	napi_enable(&priv->napi);
+	netif_start_queue(ndev);
+
+	return 0;
+err_mdio:
+	phy_disconnect(ndev->phydev);
+err_syscon:
+	sun8i_emac_unset_syscon(ndev);
+err_irq:
+	free_irq(priv->irq, ndev);
+	return err;
+}
+
+/* Clean the TX ring of any accepted skb for xmit */
+static void sun8i_emac_tx_clean(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int i;
+	struct dma_desc *ddesc;
+	int frame_len;
+
+	for (i = 0; i < priv->nbdesc_tx; i++) {
+		if (priv->txl[i].skb) {
+			ddesc = priv->dd_tx + i;
+			frame_len = le32_to_cpu(ddesc->ctl) & 0x3FFF;
+			switch (priv->txl[i].map) {
+			case MAP_SINGLE:
+				dma_unmap_single(priv->dev,
+						 le32_to_cpu(ddesc->buf_addr),
+						 frame_len, DMA_TO_DEVICE);
+				break;
+			case MAP_PAGE:
+				dma_unmap_page(priv->dev,
+					       le32_to_cpu(ddesc->buf_addr),
+					       frame_len, DMA_TO_DEVICE);
+				break;
+			default:
+				dev_err(priv->dev, "Trying to free an empty slot\n");
+				continue;
+			}
+			dev_kfree_skb_any(priv->txl[i].skb);
+			priv->txl[i].skb = NULL;
+			ddesc->ctl = 0;
+			ddesc->status = DCLEAN;
+		}
+	}
+	priv->tx_slot = 0;
+	priv->tx_dirty = 0;
+}
+
+/* Clean the RX ring */
+static void sun8i_emac_rx_clean(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int i;
+	struct dma_desc *ddesc;
+
+	/* clean RX ring */
+	for (i = 0; i < priv->nbdesc_rx; i++)
+		if (priv->rx_skb[i]) {
+			ddesc = priv->dd_rx + i;
+			dma_unmap_single(priv->dev,
+					 le32_to_cpu(ddesc->buf_addr),
+					 DESC_BUF_MAX, DMA_FROM_DEVICE);
+			dev_kfree_skb_any(priv->rx_skb[i]);
+			priv->rx_skb[i] = NULL;
+		}
+}
+
+static int sun8i_emac_stop(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	napi_disable(&priv->napi);
+
+	sun8i_emac_stop_tx(ndev);
+	sun8i_emac_stop_rx(ndev);
+
+	phy_stop(ndev->phydev);
+	phy_disconnect(ndev->phydev);
+
+	sun8i_emac_mdio_unregister(ndev);
+
+	sun8i_emac_unset_syscon(ndev);
+
+	free_irq(priv->irq, ndev);
+
+	sun8i_emac_rx_clean(ndev);
+	sun8i_emac_tx_clean(ndev);
+
+	kfree(priv->rx_skb);
+	kfree(priv->txl);
+
+	dma_free_coherent(priv->dev, priv->nbdesc_rx * sizeof(struct dma_desc),
+			  priv->dd_rx, priv->dd_rx_phy);
+	dma_free_coherent(priv->dev, priv->nbdesc_tx * sizeof(struct dma_desc),
+			  priv->dd_tx, priv->dd_tx_phy);
+
+	return 0;
+}
+
+static netdev_tx_t sun8i_emac_xmit(struct sk_buff *skb, struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct dma_desc *ddesc;
+	struct dma_desc *first;
+	int i = 0, rbd_first;
+	unsigned int len, fraglen, tlen;
+	u32 v;
+	int n;
+	int nf;
+	const skb_frag_t *frag;
+	int do_csum = 0;
+
+	if (skb_put_padto(skb, ETH_ZLEN))
+		return NETDEV_TX_OK;
+	len = skb_headlen(skb);
+
+	n = skb_shinfo(skb)->nr_frags;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+		do_csum = 1;
+		priv->estats.tx_hw_csum++;
+	}
+	netif_dbg(priv, tx_queued, ndev, "%s len=%u skblen=%u %x\n", __func__,
+		  len, skb->len,
+		  (skb->ip_summed == CHECKSUM_PARTIAL));
+
+	/* check for contigous space
+	 * We need at least 1(skb->data) + n(numfrags) + 1(one clean slot)
+	 */
+	if (rb_tx_numfreedesc(ndev) < n + 2) {
+		dev_err_ratelimited(priv->dev, "BUG!: TX is full %d %d\n",
+				    priv->tx_dirty, priv->tx_slot);
+		netif_stop_queue(ndev);
+		return NETDEV_TX_BUSY;
+	}
+	i = priv->tx_slot;
+
+	ddesc = priv->dd_tx + i;
+	first = priv->dd_tx + i;
+	rbd_first = i;
+
+	ddesc->buf_addr = dma_map_single(priv->dev, skb->data, len,
+					 DMA_TO_DEVICE);
+	if (dma_mapping_error(priv->dev, ddesc->buf_addr)) {
+		dev_err(priv->dev, "ERROR: Cannot map buffer for DMA\n");
+		goto xmit_error;
+	}
+	/* We cannot direcly use cpu_to_le32() after dma_map_single
+	 * since dma_mapping_error use it
+	 */
+	ddesc->buf_addr = cpu_to_le32(ddesc->buf_addr);
+	priv->txl[i].map = MAP_SINGLE;
+	priv->txl[i].skb = skb;
+
+	tlen = len;
+	ddesc->ctl = le32_to_cpu(len);
+	/* Undocumented bit that make it works
+	 * Without it, packets never be sent on H3 SoC
+	 */
+	ddesc->ctl |= EMAC_MAGIC_TX_BIT;
+	if (do_csum)
+		ddesc->ctl |= EMAC_TX_DO_CRC;
+
+	/* handle fragmented skb, one descriptor per fragment  */
+	for (nf = 0; nf < n; nf++) {
+		frag = &skb_shinfo(skb)->frags[nf];
+		rb_inc(&i, priv->nbdesc_tx);
+		priv->txl[i].skb = skb;
+		ddesc = priv->dd_tx + i;
+		fraglen = skb_frag_size(frag);
+		ddesc->ctl = le32_to_cpu(fraglen);
+		tlen += fraglen,
+		ddesc->ctl |= EMAC_MAGIC_TX_BIT;
+		if (do_csum)
+			ddesc->ctl |= EMAC_TX_DO_CRC;
+
+		ddesc->buf_addr = skb_frag_dma_map(priv->dev, frag, 0,
+				fraglen, DMA_TO_DEVICE);
+		if (dma_mapping_error(priv->dev, ddesc->buf_addr)) {
+			dev_err(priv->dev, "Cannot map buffer for DMA\n");
+			goto xmit_error;
+		}
+		/* Cannot directly use cpu_to_le32() after skb_frag_dma_map
+		 * since dma_mapping_error use it
+		 */
+		ddesc->buf_addr = cpu_to_le32(ddesc->buf_addr);
+		priv->txl[i].map = MAP_PAGE;
+		ddesc->status = EMAC_COULD_BE_USED_BY_DMA;
+	}
+
+	/* frame end */
+	ddesc->ctl |= EMAC_DSC_TX_LAST;
+	/* We want an interrupt after transmission */
+	ddesc->ctl |= EMAC_WANT_INT;
+
+	rb_inc(&i, priv->nbdesc_tx);
+
+	/* frame begin */
+	first->ctl |= EMAC_DSC_TX_FIRST;
+	wmb();/* EMAC_COULD_BE_USED_BY_DMA must be the last value written */
+	first->status = EMAC_COULD_BE_USED_BY_DMA;
+	priv->tx_slot = i;
+
+	/* Trying to optimize this (recording DMA start/stop) seems
+	 * to lead to errors. So we always start DMA.
+	 */
+	v = readl(priv->base + EMAC_TX_CTL1);
+	v |= EMAC_TX_DMA_START;
+	v |= EMAC_TX_DMA_EN;
+	writel_relaxed(v, priv->base + EMAC_TX_CTL1);
+
+	netdev_sent_queue(ndev, skb->len);
+
+	if (rb_tx_numfreedesc(ndev) < MAX_SKB_FRAGS + 1) {
+		netif_stop_queue(ndev);
+		priv->estats.tx_stop_queue++;
+	}
+	priv->estats.tx_used_desc = rb_tx_numfreedesc(ndev);
+	priv->ndev->stats.tx_packets++;
+	priv->ndev->stats.tx_bytes += tlen;
+
+	return NETDEV_TX_OK;
+
+xmit_error:
+	/* destroy skb and return TX OK Documentation/DMA-API-HOWTO.txt */
+	/* clean descritors from rbd_first to i */
+	ddesc->ctl = 0;
+	/* setting status to DCLEAN is the last value to be set */
+	wmb();
+	ddesc->status = DCLEAN;
+	do {
+		ddesc = priv->dd_tx + rbd_first;
+		ddesc->ctl = 0;
+		/* setting status to DCLEAN is the last value to be set */
+		wmb();
+		ddesc->status = DCLEAN;
+		rb_inc(&rbd_first, priv->nbdesc_tx);
+	} while (rbd_first != i);
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static int sun8i_emac_change_mtu(struct net_device *ndev, int new_mtu)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int max_mtu;
+
+	dev_info(priv->dev, "%s set MTU to %d\n", __func__, new_mtu);
+
+	if (netif_running(ndev)) {
+		dev_err(priv->dev, "%s: must be stopped to change its MTU\n",
+			ndev->name);
+		return -EBUSY;
+	}
+
+	max_mtu = SKB_MAX_HEAD(NET_SKB_PAD + NET_IP_ALIGN);
+
+	if ((new_mtu < 68) || (new_mtu > max_mtu)) {
+		dev_err(priv->dev, "%s: invalid MTU, max MTU is: %d\n",
+			ndev->name, max_mtu);
+		return -EINVAL;
+	}
+
+	ndev->mtu = new_mtu;
+	netdev_update_features(ndev);
+	return 0;
+}
+
+static int sun8i_emac_set_features(struct net_device *ndev,
+				   netdev_features_t features)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v;
+
+	v = readl(priv->base + EMAC_BASIC_CTL0);
+	if (features & NETIF_F_LOOPBACK && netif_running(ndev)) {
+		netif_info(priv, hw, ndev, "Set loopback features");
+		v |= BIT(1);
+	} else {
+		netif_info(priv, hw, ndev, "Unset loopback features");
+		v &= ~BIT(1);
+	}
+	writel(v, priv->base + EMAC_BASIC_CTL0);
+
+	v = readl(priv->base + EMAC_RX_CTL0);
+	if (features & NETIF_F_RXCSUM) {
+		v |= EMAC_RX_DO_CRC;
+		netif_info(priv, hw, ndev, "Doing RX CRC check by hardware");
+	} else {
+		v &= ~EMAC_RX_DO_CRC;
+		netif_info(priv, hw, ndev, "No RX CRC check by hardware");
+	}
+	if (features & NETIF_F_RXFCS) {
+		v &= ~EMAC_RX_STRIP_FCS;
+		netif_info(priv, hw, ndev, "Keep FCS");
+	} else {
+		v |= EMAC_RX_STRIP_FCS;
+		netif_info(priv, hw, ndev, "Strip FCS");
+	}
+	writel(v, priv->base + EMAC_RX_CTL0);
+
+	netif_dbg(priv, drv, ndev, "%s %llx %x\n", __func__, features, v);
+
+	return 0;
+}
+
+static void sun8i_emac_set_rx_mode(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v = 0;
+	int i = 0;
+	struct netdev_hw_addr *ha;
+
+	/* Receive all multicast frames */
+	v |= BIT(16);
+	/* Receive all control frames */
+	v |= BIT(13);
+	if (ndev->flags & IFF_PROMISC)
+		v |= BIT(1);
+	if (netdev_uc_count(ndev) > 7) {
+		v |= BIT(1);
+	} else {
+		netdev_for_each_uc_addr(ha, ndev) {
+			i++;
+			sun8i_emac_set_macaddr(priv, ha->addr, i);
+		}
+	}
+	writel(v, priv->base + EMAC_RX_FRM_FLT);
+}
+
+static void sun8i_emac_tx_timeout(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	netdev_err(ndev, "%s\n", __func__);
+
+	sun8i_emac_stop_tx(ndev);
+
+	sun8i_emac_tx_clean(ndev);
+
+	/* write start of the new TX ring descriptor */
+	writel(priv->dd_tx_phy, priv->base + EMAC_TX_DESC_LIST);
+
+	sun8i_emac_start_tx(ndev);
+
+	netdev_reset_queue(ndev);
+
+	priv->estats.tx_timeout++;
+	ndev->stats.tx_errors++;
+	netif_wake_queue(ndev);
+}
+
+static int sun8i_emac_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
+{
+	struct phy_device *phydev = ndev->phydev;
+
+	if (!netif_running(ndev))
+		return -EINVAL;
+
+	if (!phydev)
+		return -ENODEV;
+
+	return phy_mii_ioctl(phydev, rq, cmd);
+}
+
+static int sun8i_emac_check_if_running(struct net_device *ndev)
+{
+	if (!netif_running(ndev))
+		return -EINVAL;
+	return 0;
+}
+
+static int sun8i_emac_get_sset_count(struct net_device *ndev, int sset)
+{
+	switch (sset) {
+	case ETH_SS_STATS:
+		return ARRAY_SIZE(estats_str);
+	}
+	return -EOPNOTSUPP;
+}
+
+static int sun8i_emac_ethtool_get_settings(struct net_device *ndev,
+					   struct ethtool_cmd *cmd)
+{
+	struct phy_device *phy = ndev->phydev;
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	if (!phy) {
+		netdev_err(ndev, "%s: %s: PHY is not registered\n",
+			   __func__, ndev->name);
+		return -ENODEV;
+	}
+
+	if (!netif_running(ndev)) {
+		dev_err(priv->dev, "interface disabled: we cannot track link speed / duplex setting\n");
+		return -EBUSY;
+	}
+
+	return phy_ethtool_gset(phy, cmd);
+}
+
+static int sun8i_emac_ethtool_set_settings(struct net_device *ndev,
+					   struct ethtool_cmd *cmd)
+{
+	struct phy_device *phy = ndev->phydev;
+
+	return phy_ethtool_sset(phy, cmd);
+}
+
+static void sun8i_emac_ethtool_getdrvinfo(struct net_device *ndev,
+					  struct ethtool_drvinfo *info)
+{
+	strlcpy(info->driver, "sun8i_emac", sizeof(info->driver));
+	strcpy(info->version, "00");
+	info->fw_version[0] = '\0';
+}
+
+static void sun8i_emac_ethtool_stats(struct net_device *ndev,
+				     struct ethtool_stats *dummy, u64 *data)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	memcpy(data, &priv->estats,
+	       sun8i_emac_get_sset_count(ndev, ETH_SS_STATS) * sizeof(u64));
+}
+
+static void sun8i_emac_ethtool_strings(struct net_device *dev, u32 stringset,
+				       u8 *buffer)
+{
+	switch (stringset) {
+	case ETH_SS_STATS:
+		memcpy(buffer, &estats_str, sizeof(estats_str));
+		break;
+	}
+}
+
+static u32 sun8i_emac_ethtool_getmsglevel(struct net_device *ndev)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	return priv->msg_enable;
+}
+
+static void sun8i_emac_ethtool_setmsglevel(struct net_device *ndev, u32 level)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	priv->msg_enable = level;
+}
+
+static void sun8i_emac_get_pauseparam(struct net_device *ndev,
+				      struct ethtool_pauseparam *pause)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	pause->rx_pause = 0;
+	pause->tx_pause = 0;
+	pause->autoneg = ndev->phydev->autoneg;
+
+	if (priv->flow_ctrl & EMAC_FLOW_RX)
+		pause->rx_pause = 1;
+	if (priv->flow_ctrl & EMAC_FLOW_TX)
+		pause->tx_pause = 1;
+}
+
+static int sun8i_emac_set_pauseparam(struct net_device *ndev,
+				     struct ethtool_pauseparam *pause)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	struct phy_device *phy = ndev->phydev;
+	int new_pause = 0;
+	int ret = 0;
+
+	if (pause->rx_pause)
+		new_pause |= EMAC_FLOW_RX;
+	if (pause->tx_pause)
+		new_pause |= EMAC_FLOW_TX;
+
+	priv->flow_ctrl = new_pause;
+	phy->autoneg = pause->autoneg;
+
+	if (phy->autoneg) {
+		if (netif_running(ndev))
+			ret = phy_start_aneg(phy);
+	} else {
+		sun8i_emac_flow_ctrl(priv, phy->duplex, priv->flow_ctrl);
+	}
+	return ret;
+}
+
+static void sun8i_emac_ethtool_get_ringparam(struct net_device *ndev,
+					     struct ethtool_ringparam *ring)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+
+	ring->rx_pending = priv->nbdesc_rx;
+	ring->tx_pending = priv->nbdesc_tx;
+}
+
+static int sun8i_emac_ethtool_set_ringparam(struct net_device *ndev,
+					    struct ethtool_ringparam *ring)
+{
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	int err;
+
+	if (ring->rx_max_pending || ring->rx_mini_max_pending ||
+	    ring->rx_jumbo_max_pending || ring->rx_mini_pending ||
+	    ring->rx_jumbo_pending || ring->tx_max_pending)
+		return -EINVAL;
+
+	if (ring->tx_pending < MAX_SKB_FRAGS + 1) {
+		netdev_err(ndev, "The number of TX descriptors is too low");
+		return -EINVAL;
+	}
+
+	sun8i_emac_stop_tx(ndev);
+	sun8i_emac_stop_rx(ndev);
+
+	sun8i_emac_rx_clean(ndev);
+	sun8i_emac_tx_clean(ndev);
+
+	kfree(priv->rx_skb);
+	kfree(priv->txl);
+
+	dma_free_coherent(priv->dev, priv->nbdesc_rx * sizeof(struct dma_desc),
+			  priv->dd_rx, priv->dd_rx_phy);
+	dma_free_coherent(priv->dev, priv->nbdesc_tx * sizeof(struct dma_desc),
+			  priv->dd_tx, priv->dd_tx_phy);
+
+	priv->nbdesc_rx = ring->rx_pending;
+	priv->nbdesc_tx = ring->tx_pending;
+	err = sun8i_emac_alloc_rings(ndev);
+	if (err) {
+		/* Fatal error, we cannot re start */
+		netdev_err(ndev, "Fail to allocate rings\n");
+		return -EFAULT;
+	}
+
+	sun8i_emac_start_rx(ndev);
+	sun8i_emac_start_tx(ndev);
+
+	netif_start_queue(ndev);
+
+	netdev_info(ndev, "Ring Param settings: rx: %d, tx %d\n",
+		    ring->rx_pending, ring->tx_pending);
+	return 0;
+}
+
+static const struct ethtool_ops sun8i_emac_ethtool_ops = {
+	.begin = sun8i_emac_check_if_running,
+	.get_settings = sun8i_emac_ethtool_get_settings,
+	.set_settings = sun8i_emac_ethtool_set_settings,
+	.get_link = ethtool_op_get_link,
+	.get_pauseparam = sun8i_emac_get_pauseparam,
+	.set_pauseparam = sun8i_emac_set_pauseparam,
+	.get_ethtool_stats = sun8i_emac_ethtool_stats,
+	.get_strings = sun8i_emac_ethtool_strings,
+	.get_sset_count = sun8i_emac_get_sset_count,
+	.get_drvinfo = sun8i_emac_ethtool_getdrvinfo,
+	.get_msglevel = sun8i_emac_ethtool_getmsglevel,
+	.set_msglevel = sun8i_emac_ethtool_setmsglevel,
+	.get_ringparam = sun8i_emac_ethtool_get_ringparam,
+	.set_ringparam = sun8i_emac_ethtool_set_ringparam,
+};
+
+static const struct net_device_ops sun8i_emac_netdev_ops = {
+	.ndo_init = sun8i_emac_init,
+	.ndo_uninit = sun8i_emac_uninit,
+	.ndo_open = sun8i_emac_open,
+	.ndo_start_xmit = sun8i_emac_xmit,
+	.ndo_stop = sun8i_emac_stop,
+	.ndo_change_mtu = sun8i_emac_change_mtu,
+	.ndo_set_features = sun8i_emac_set_features,
+	.ndo_set_rx_mode = sun8i_emac_set_rx_mode,
+	.ndo_tx_timeout = sun8i_emac_tx_timeout,
+	.ndo_do_ioctl = sun8i_emac_ioctl,
+	.ndo_set_mac_address = eth_mac_addr,
+};
+
+/* No locking in this function since it is guaranteed to be run once and
+ * do actions only done here:
+ * - Scheduling NAPI
+ * - Stopping interrupts
+ * - Updating stats
+ *
+ * Even when not enabled via EMAC_INT_EN, some interrupt could fire, so we need
+ * to handle all of them.
+ * Interrupts know to fire when not enabled are:
+ * - EMAC_TX_DMA_STOP_INT
+ * - EMAC_TX_BUF_UA_INT
+ * - EMAC_TX_EARLY_INT
+ * - EMAC_RX_BUF_UA_INT
+ * - EMAC_RX_EARLY_INT
+ */
+static irqreturn_t sun8i_emac_dma_interrupt(int irq, void *dev_id)
+{
+	struct net_device *ndev = dev_id;
+	struct sun8i_emac_priv *priv = netdev_priv(ndev);
+	u32 v, u;
+
+	v = readl(priv->base + EMAC_INT_STA);
+
+	/* When this bit is asserted, a frame transmission is completed. */
+	if (v & EMAC_TX_INT) {
+		priv->estats.tx_int++;
+		writel(0, priv->base + EMAC_INT_EN);
+		napi_schedule(&priv->napi);
+	}
+
+	/* When this bit is asserted, the TX DMA FSM is stopped.
+	 * For the moment only a call to tx_timeout cause this interrupt
+	 * to fire.
+	 */
+	if (v & EMAC_TX_DMA_STOP_INT)
+		priv->estats.tx_dma_stop++;
+
+	/* When this asserted, the TX DMA can not acquire next TX descriptor
+	 * and TX DMA FSM is suspended.
+	*/
+	if (v & EMAC_TX_BUF_UA_INT) {
+		priv->estats.tx_dma_ua++;
+		writel(0, priv->base + EMAC_INT_EN);
+		napi_schedule(&priv->napi);
+	}
+
+	if (v & EMAC_TX_TIMEOUT_INT)
+		priv->estats.tx_timeout_int++;
+
+	if (v & EMAC_TX_UNDERFLOW_INT)
+		priv->estats.tx_underflow_int++;
+
+	/* When this bit asserted , the frame is transmitted to FIFO totally. */
+	if (v & EMAC_TX_EARLY_INT)
+		priv->estats.tx_early_int++;
+
+	/* When this bit is asserted, a frame reception is completed  */
+	if (v & EMAC_RX_INT) {
+		priv->estats.rx_int++;
+		writel(0, priv->base + EMAC_INT_EN);
+		napi_schedule(&priv->napi);
+	}
+
+	/* When this asserted, the RX DMA can not acquire next RX descriptor
+	 * and RX DMA FSM is suspended.
+	*/
+	if (v & EMAC_RX_BUF_UA_INT) {
+		u = readl(priv->base + EMAC_RX_CTL1);
+		writel(u | EMAC_RX_DMA_START, priv->base + EMAC_RX_CTL1);
+		priv->estats.rx_dma_ua++;
+	}
+
+	/* Same as TX DMA STOP, but never hit it */
+	if (v & EMAC_RX_DMA_STOP_INT)
+		priv->estats.rx_dma_stop++;
+
+	if (v & EMAC_RX_TIMEOUT_INT)
+		priv->estats.rx_timeout_int++;
+
+	if (v & EMAC_RX_OVERFLOW_INT)
+		priv->estats.rx_overflow_int++;
+
+	if (v & EMAC_RX_EARLY_INT)
+		priv->estats.rx_early_int++;
+
+	if (v & EMAC_RGMII_STA_INT)
+		priv->estats.rgmii_state_int++;
+
+	/* the datasheet state those register as read-only
+	 * but nothing work(freeze) without writing to it
+	 */
+	writel(v, priv->base + EMAC_INT_STA);
+
+	return IRQ_HANDLED;
+}
+
+static int sun8i_emac_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct sun8i_emac_priv *priv;
+	struct net_device *ndev;
+	struct resource *res;
+	int ret;
+
+	ndev = alloc_etherdev(sizeof(*priv));
+	if (!ndev)
+		return -ENOMEM;
+
+	SET_NETDEV_DEV(ndev, &pdev->dev);
+	priv = netdev_priv(ndev);
+	platform_set_drvdata(pdev, ndev);
+
+	priv->variant = of_device_get_match_data(&pdev->dev);
+	if (!priv->variant) {
+		dev_err(&pdev->dev, "Missing sun8i-emac variant\n");
+		return -EINVAL;
+	}
+
+	priv->phy_node = of_parse_phandle(node, "phy", 0);
+	if (!priv->phy_node) {
+		netdev_err(ndev, "No associated PHY\n");
+		return -ENODEV;
+	}
+
+	priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+						       "syscon");
+	if (IS_ERR(priv->regmap)) {
+		ret = PTR_ERR(priv->regmap);
+		dev_err(&pdev->dev, "unable to map SYSCON:%d\n", ret);
+		return ret;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->base)) {
+		ret = PTR_ERR(priv->base);
+		dev_err(&pdev->dev, "Cannot request MMIO: %d\n", ret);
+		return ret;
+	}
+
+	priv->ahb_clk = devm_clk_get(&pdev->dev, "ahb");
+	if (IS_ERR(priv->ahb_clk)) {
+		ret = PTR_ERR(priv->ahb_clk);
+		dev_err(&pdev->dev, "Cannot get AHB clock err=%d\n", ret);
+		goto probe_err;
+	}
+
+	priv->rst_mac = devm_reset_control_get_optional(&pdev->dev, "ahb");
+	if (IS_ERR(priv->rst_mac)) {
+		ret = PTR_ERR(priv->rst_mac);
+		if (ret == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		dev_info(&pdev->dev, "No MAC reset control found %d\n", ret);
+		priv->rst_mac = NULL;
+	}
+
+	priv->phy_interface = of_get_phy_mode(node);
+	if (priv->phy_interface < 0) {
+		netdev_err(ndev, "PHY interface mode node unspecified\n");
+		return priv->phy_interface;
+	}
+
+	switch (priv->phy_interface) {
+	case PHY_INTERFACE_MODE_MII:
+		if (!priv->variant->support_mii)
+			return -EINVAL;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		if (!priv->variant->support_rmii)
+			return -EINVAL;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+		if (!priv->variant->support_rgmii)
+			return -EINVAL;
+		break;
+	default:
+		netdev_err(ndev, "Unsupported interface mode: %s",
+			   phy_modes(priv->phy_interface));
+		return -EINVAL;
+	}
+
+	if (priv->phy_interface == priv->variant->internal_phy)
+		priv->use_internal_phy = true;
+
+	if (priv->use_internal_phy) {
+		priv->ephy_clk = devm_clk_get(&pdev->dev, "ephy");
+		if (IS_ERR(priv->ephy_clk)) {
+			ret = PTR_ERR(priv->ephy_clk);
+			dev_err(&pdev->dev, "Cannot get EPHY clock err=%d\n",
+				ret);
+			goto probe_err;
+		}
+
+		priv->rst_ephy = devm_reset_control_get_optional(&pdev->dev,
+								 "ephy");
+		if (IS_ERR(priv->rst_ephy)) {
+			ret = PTR_ERR(priv->rst_ephy);
+			if (ret == -EPROBE_DEFER)
+				goto probe_err;
+			dev_info(&pdev->dev,
+				 "No EPHY reset control found %d\n", ret);
+			priv->rst_ephy = NULL;
+		}
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq < 0) {
+		ret = priv->irq;
+		dev_err(&pdev->dev, "Cannot claim IRQ: %d\n", ret);
+		goto probe_err;
+	}
+
+	spin_lock_init(&priv->tx_lock);
+
+	ndev->netdev_ops = &sun8i_emac_netdev_ops;
+	ndev->ethtool_ops = &sun8i_emac_ethtool_ops;
+
+	priv->ndev = ndev;
+	priv->dev = &pdev->dev;
+
+	ndev->hw_features = NETIF_F_SG | NETIF_F_HIGHDMA;
+	ndev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
+		NETIF_F_RXCSUM;
+	ndev->features |= ndev->hw_features;
+	ndev->hw_features |= NETIF_F_RXFCS;
+	ndev->hw_features |= NETIF_F_RXALL;
+	ndev->hw_features |= NETIF_F_LOOPBACK;
+	ndev->priv_flags |= IFF_UNICAST_FLT;
+
+	ndev->watchdog_timeo = msecs_to_jiffies(5000);
+	netif_carrier_off(ndev);
+
+	/* Benched on OPIPC with 100M, setting more than 256 does not give any
+	 * perf boost
+	 */
+	priv->nbdesc_rx = 128;
+	priv->nbdesc_tx = 256;
+
+	ret = register_netdev(ndev);
+	if (ret) {
+		dev_err(&pdev->dev, "ERROR: Register %s failed\n", ndev->name);
+		goto probe_err;
+	}
+
+	return 0;
+
+probe_err:
+	free_netdev(ndev);
+	return ret;
+}
+
+static int sun8i_emac_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+
+	unregister_netdev(ndev);
+	platform_set_drvdata(pdev, NULL);
+	free_netdev(ndev);
+
+	return 0;
+}
+
+static const struct of_device_id sun8i_emac_of_match_table[] = {
+	{ .compatible = "allwinner,sun8i-a83t-emac",
+	  .data = &emac_variant_a83t },
+	{ .compatible = "allwinner,sun8i-h3-emac",
+	  .data = &emac_variant_h3 },
+	{ .compatible = "allwinner,sun50i-a64-emac",
+	  .data = &emac_variant_a64 },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sun8i_emac_of_match_table);
+
+static struct platform_driver sun8i_emac_driver = {
+	.probe          = sun8i_emac_probe,
+	.remove         = sun8i_emac_remove,
+	.driver         = {
+		.name           = "sun8i-emac",
+		.of_match_table	= sun8i_emac_of_match_table,
+	},
+};
+
+module_platform_driver(sun8i_emac_driver);
+
+MODULE_DESCRIPTION("sun8i Ethernet driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Corentin Labbe <clabbe.montjoie@xxxxxxxxx");
-- 
2.7.3