drivers/net/ethernet/ti/davinci_emac.c

/*
 * DaVinci Ethernet Medium Access Controller
 *
 * DaVinci EMAC is based upon CPPI 3.0 TI DMA engine
 *
 * Copyright (C) 2009 Texas Instruments.
 *
 * ---------------------------------------------------------------------------
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 * ---------------------------------------------------------------------------
 * History:
 * 0-5 A number of folks worked on this driver in bits and pieces but the major
 *     contribution came from Suraj Iyer and Anant Gole
 * 6.0 Anant Gole - rewrote the driver as per Linux conventions
 * 6.1 Chaithrika U S - added support for Gigabit and RMII features,
 *     PHY layer usage
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/highmem.h>
#include <linux/proc_fs.h>
#include <linux/ctype.h>
#include <linux/spinlock.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/semaphore.h>
#include <linux/phy.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#include <linux/pm_runtime.h>
#include <linux/davinci_emac.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_net.h>

#include <asm/irq.h>
#include <asm/page.h>

#include "davinci_cpdma.h"

static int debug_level;
module_param(debug_level, int, 0);
MODULE_PARM_DESC(debug_level, "DaVinci EMAC debug level (NETIF_MSG bits)");

/* Netif debug messages possible */
#define DAVINCI_EMAC_DEBUG	(NETIF_MSG_DRV | \
				NETIF_MSG_PROBE | \
				NETIF_MSG_LINK | \
				NETIF_MSG_TIMER | \
				NETIF_MSG_IFDOWN | \
				NETIF_MSG_IFUP | \
				NETIF_MSG_RX_ERR | \
				NETIF_MSG_TX_ERR | \
				NETIF_MSG_TX_QUEUED | \
				NETIF_MSG_INTR | \
				NETIF_MSG_TX_DONE | \
				NETIF_MSG_RX_STATUS | \
				NETIF_MSG_PKTDATA | \
				NETIF_MSG_HW | \
				NETIF_MSG_WOL)

/* version info */
#define EMAC_MAJOR_VERSION	6
#define EMAC_MINOR_VERSION	1
#define EMAC_MODULE_VERSION	"6.1"
MODULE_VERSION(EMAC_MODULE_VERSION);
static const char emac_version_string[] = "TI DaVinci EMAC Linux v6.1";

/* Configuration items */
#define EMAC_DEF_PASS_CRC		(0) /* Do not pass CRC up to frames */
#define EMAC_DEF_QOS_EN			(0) /* EMAC proprietary QoS disabled */
#define EMAC_DEF_NO_BUFF_CHAIN		(0) /* No buffer chain */
#define EMAC_DEF_MACCTRL_FRAME_EN	(0) /* Discard Maccontrol frames */
#define EMAC_DEF_SHORT_FRAME_EN		(0) /* Discard short frames */
#define EMAC_DEF_ERROR_FRAME_EN		(0) /* Discard error frames */
#define EMAC_DEF_PROM_EN		(0) /* Promiscuous disabled */
#define EMAC_DEF_PROM_CH		(0) /* Promiscuous channel is 0 */
#define EMAC_DEF_BCAST_EN		(1) /* Broadcast enabled */
#define EMAC_DEF_BCAST_CH		(0) /* Broadcast channel is 0 */
#define EMAC_DEF_MCAST_EN		(1) /* Multicast enabled */
#define EMAC_DEF_MCAST_CH		(0) /* Multicast channel is 0 */

#define EMAC_DEF_TXPRIO_FIXED		(1) /* TX Priority is fixed */
#define EMAC_DEF_TXPACING_EN		(0) /* TX pacing NOT supported*/

#define EMAC_DEF_BUFFER_OFFSET		(0) /* Buffer offset to DMA (future) */
#define EMAC_DEF_MIN_ETHPKTSIZE		(60) /* Minimum ethernet pkt size */
#define EMAC_DEF_MAX_FRAME_SIZE		(1500 + 14 + 4 + 4)
#define EMAC_DEF_TX_CH			(0) /* Default 0th channel */
#define EMAC_DEF_RX_CH			(0) /* Default 0th channel */
#define EMAC_DEF_RX_NUM_DESC		(128)
#define EMAC_DEF_MAX_TX_CH		(1) /* Max TX channels configured */
#define EMAC_DEF_MAX_RX_CH		(1) /* Max RX channels configured */
#define EMAC_POLL_WEIGHT		(64) /* Default NAPI poll weight */

/* Buffer descriptor parameters */
#define EMAC_DEF_TX_MAX_SERVICE		(32) /* TX max service BD's */
#define EMAC_DEF_RX_MAX_SERVICE		(64) /* should = netdev->weight */

/* EMAC register related defines */
#define EMAC_ALL_MULTI_REG_VALUE	(0xFFFFFFFF)
#define EMAC_NUM_MULTICAST_BITS		(64)
#define EMAC_TX_CONTROL_TX_ENABLE_VAL	(0x1)
#define EMAC_RX_CONTROL_RX_ENABLE_VAL	(0x1)
#define EMAC_MAC_HOST_ERR_INTMASK_VAL	(0x2)
#define EMAC_RX_UNICAST_CLEAR_ALL	(0xFF)
#define EMAC_INT_MASK_CLEAR		(0xFF)

/* RX MBP register bit positions */
#define EMAC_RXMBP_PASSCRC_MASK		BIT(30)
#define EMAC_RXMBP_QOSEN_MASK		BIT(29)
#define EMAC_RXMBP_NOCHAIN_MASK		BIT(28)
#define EMAC_RXMBP_CMFEN_MASK		BIT(24)
#define EMAC_RXMBP_CSFEN_MASK		BIT(23)
#define EMAC_RXMBP_CEFEN_MASK		BIT(22)
#define EMAC_RXMBP_CAFEN_MASK		BIT(21)
#define EMAC_RXMBP_PROMCH_SHIFT		(16)
#define EMAC_RXMBP_PROMCH_MASK		(0x7 << 16)
#define EMAC_RXMBP_BROADEN_MASK		BIT(13)
#define EMAC_RXMBP_BROADCH_SHIFT	(8)
#define EMAC_RXMBP_BROADCH_MASK		(0x7 << 8)
#define EMAC_RXMBP_MULTIEN_MASK		BIT(5)
#define EMAC_RXMBP_MULTICH_SHIFT	(0)
#define EMAC_RXMBP_MULTICH_MASK		(0x7)
#define EMAC_RXMBP_CHMASK		(0x7)

/* EMAC register definitions/bit maps used */
# define EMAC_MBP_RXPROMISC		(0x00200000)
# define EMAC_MBP_PROMISCCH(ch)		(((ch) & 0x7) << 16)
# define EMAC_MBP_RXBCAST		(0x00002000)
# define EMAC_MBP_BCASTCHAN(ch)		(((ch) & 0x7) << 8)
# define EMAC_MBP_RXMCAST		(0x00000020)
# define EMAC_MBP_MCASTCHAN(ch)		((ch) & 0x7)

/* EMAC mac_control register */
#define EMAC_MACCONTROL_TXPTYPE		BIT(9)
#define EMAC_MACCONTROL_TXPACEEN	BIT(6)
#define EMAC_MACCONTROL_GMIIEN		BIT(5)
#define EMAC_MACCONTROL_GIGABITEN	BIT(7)
#define EMAC_MACCONTROL_FULLDUPLEXEN	BIT(0)
#define EMAC_MACCONTROL_RMIISPEED_MASK	BIT(15)

/* GIGABIT MODE related bits */
#define EMAC_DM646X_MACCONTORL_GIG	BIT(7)
#define EMAC_DM646X_MACCONTORL_GIGFORCE	BIT(17)

/* EMAC mac_status register */
#define EMAC_MACSTATUS_TXERRCODE_MASK	(0xF00000)
#define EMAC_MACSTATUS_TXERRCODE_SHIFT	(20)
#define EMAC_MACSTATUS_TXERRCH_MASK	(0x7)
#define EMAC_MACSTATUS_TXERRCH_SHIFT	(16)
#define EMAC_MACSTATUS_RXERRCODE_MASK	(0xF000)
#define EMAC_MACSTATUS_RXERRCODE_SHIFT	(12)
#define EMAC_MACSTATUS_RXERRCH_MASK	(0x7)
#define EMAC_MACSTATUS_RXERRCH_SHIFT	(8)

/* EMAC RX register masks */
#define EMAC_RX_MAX_LEN_MASK		(0xFFFF)
#define EMAC_RX_BUFFER_OFFSET_MASK	(0xFFFF)

/* MAC_IN_VECTOR (0x180) register bit fields */
#define EMAC_DM644X_MAC_IN_VECTOR_HOST_INT	BIT(17)
#define EMAC_DM644X_MAC_IN_VECTOR_STATPEND_INT	BIT(16)
#define EMAC_DM644X_MAC_IN_VECTOR_RX_INT_VEC	BIT(8)
#define EMAC_DM644X_MAC_IN_VECTOR_TX_INT_VEC	BIT(0)

/** NOTE:: For DM646x the IN_VECTOR has changed */
#define EMAC_DM646X_MAC_IN_VECTOR_RX_INT_VEC	BIT(EMAC_DEF_RX_CH)
#define EMAC_DM646X_MAC_IN_VECTOR_TX_INT_VEC	BIT(16 + EMAC_DEF_TX_CH)
#define EMAC_DM646X_MAC_IN_VECTOR_HOST_INT	BIT(26)
#define EMAC_DM646X_MAC_IN_VECTOR_STATPEND_INT	BIT(27)

/* CPPI bit positions */
#define EMAC_CPPI_SOP_BIT		BIT(31)
#define EMAC_CPPI_EOP_BIT		BIT(30)
#define EMAC_CPPI_OWNERSHIP_BIT		BIT(29)
#define EMAC_CPPI_EOQ_BIT		BIT(28)
#define EMAC_CPPI_TEARDOWN_COMPLETE_BIT BIT(27)
#define EMAC_CPPI_PASS_CRC_BIT		BIT(26)
#define EMAC_RX_BD_BUF_SIZE		(0xFFFF)
#define EMAC_BD_LENGTH_FOR_CACHE	(16) /* only CPPI bytes */
#define EMAC_RX_BD_PKT_LENGTH_MASK	(0xFFFF)

/* Max hardware defines */
#define EMAC_MAX_TXRX_CHANNELS		 (8)  /* Max hardware channels */
#define EMAC_DEF_MAX_MULTICAST_ADDRESSES (64) /* Max mcast addr's */

/* EMAC Peripheral Device Register Memory Layout structure */
#define EMAC_MACINVECTOR	0x90

#define EMAC_DM646X_MACEOIVECTOR	0x94

#define EMAC_MACINTSTATRAW	0xB0
#define EMAC_MACINTSTATMASKED	0xB4
#define EMAC_MACINTMASKSET	0xB8
#define EMAC_MACINTMASKCLEAR	0xBC

#define EMAC_RXMBPENABLE	0x100
#define EMAC_RXUNICASTSET	0x104
#define EMAC_RXUNICASTCLEAR	0x108
#define EMAC_RXMAXLEN		0x10C
#define EMAC_RXBUFFEROFFSET	0x110
#define EMAC_RXFILTERLOWTHRESH	0x114

#define EMAC_MACCONTROL		0x160
#define EMAC_MACSTATUS		0x164
#define EMAC_EMCONTROL		0x168
#define EMAC_FIFOCONTROL	0x16C
#define EMAC_MACCONFIG		0x170
#define EMAC_SOFTRESET		0x174
#define EMAC_MACSRCADDRLO	0x1D0
#define EMAC_MACSRCADDRHI	0x1D4
#define EMAC_MACHASH1		0x1D8
#define EMAC_MACHASH2		0x1DC
#define EMAC_MACADDRLO		0x500
#define EMAC_MACADDRHI		0x504
#define EMAC_MACINDEX		0x508

/* EMAC statistics registers */
#define EMAC_RXGOODFRAMES	0x200
#define EMAC_RXBCASTFRAMES	0x204
#define EMAC_RXMCASTFRAMES	0x208
#define EMAC_RXPAUSEFRAMES	0x20C
#define EMAC_RXCRCERRORS	0x210
#define EMAC_RXALIGNCODEERRORS	0x214
#define EMAC_RXOVERSIZED	0x218
#define EMAC_RXJABBER		0x21C
#define EMAC_RXUNDERSIZED	0x220
#define EMAC_RXFRAGMENTS	0x224
#define EMAC_RXFILTERED		0x228
#define EMAC_RXQOSFILTERED	0x22C
#define EMAC_RXOCTETS		0x230
#define EMAC_TXGOODFRAMES	0x234
#define EMAC_TXBCASTFRAMES	0x238
#define EMAC_TXMCASTFRAMES	0x23C
#define EMAC_TXPAUSEFRAMES	0x240
#define EMAC_TXDEFERRED		0x244
#define EMAC_TXCOLLISION	0x248
#define EMAC_TXSINGLECOLL	0x24C
#define EMAC_TXMULTICOLL	0x250
#define EMAC_TXEXCESSIVECOLL	0x254
#define EMAC_TXLATECOLL		0x258
#define EMAC_TXUNDERRUN		0x25C
#define EMAC_TXCARRIERSENSE	0x260
#define EMAC_TXOCTETS		0x264
#define EMAC_NETOCTETS		0x280
#define EMAC_RXSOFOVERRUNS	0x284
#define EMAC_RXMOFOVERRUNS	0x288
#define EMAC_RXDMAOVERRUNS	0x28C

/* EMAC DM644x control registers */
#define EMAC_CTRL_EWCTL		(0x4)
#define EMAC_CTRL_EWINTTCNT	(0x8)

/* EMAC DM644x control module masks */
#define EMAC_DM644X_EWINTCNT_MASK	0x1FFFF
#define EMAC_DM644X_INTMIN_INTVL	0x1
#define EMAC_DM644X_INTMAX_INTVL	(EMAC_DM644X_EWINTCNT_MASK)

/* EMAC DM646X control module registers */
#define EMAC_DM646X_CMINTCTRL	0x0C
#define EMAC_DM646X_CMRXINTEN	0x14
#define EMAC_DM646X_CMTXINTEN	0x18
#define EMAC_DM646X_CMRXINTMAX	0x70
#define EMAC_DM646X_CMTXINTMAX	0x74

/* EMAC DM646X control module masks */
#define EMAC_DM646X_INTPACEEN		(0x3 << 16)
#define EMAC_DM646X_INTPRESCALE_MASK	(0x7FF << 0)
#define EMAC_DM646X_CMINTMAX_CNT	63
#define EMAC_DM646X_CMINTMIN_CNT	2
#define EMAC_DM646X_CMINTMAX_INTVL	(1000 / EMAC_DM646X_CMINTMIN_CNT)
#define EMAC_DM646X_CMINTMIN_INTVL	((1000 / EMAC_DM646X_CMINTMAX_CNT) + 1)


/* EMAC EOI codes for C0 */
#define EMAC_DM646X_MAC_EOI_C0_RXEN	(0x01)
#define EMAC_DM646X_MAC_EOI_C0_TXEN	(0x02)

/* EMAC Stats Clear Mask */
#define EMAC_STATS_CLR_MASK    (0xFFFFFFFF)

/* emac_priv: EMAC private data structure
 *
 * EMAC adapter private data structure
 */
struct emac_priv {
	u32 msg_enable;
	struct net_device *ndev;
	struct platform_device *pdev;
	struct napi_struct napi;
	char mac_addr[6];
	void __iomem *remap_addr;
	u32 emac_base_phys;
	void __iomem *emac_base;
	void __iomem *ctrl_base;
	struct cpdma_ctlr *dma;
	struct cpdma_chan *txchan;
	struct cpdma_chan *rxchan;
	u32 link; /* 1=link on, 0=link off */
	u32 speed; /* 0=Auto Neg, 1=No PHY, 10,100, 1000 - mbps */
	u32 duplex; /* Link duplex: 0=Half, 1=Full */
	u32 rx_buf_size;
	u32 isr_count;
	u32 coal_intvl;
	u32 bus_freq_mhz;
	u8 rmii_en;
	u8 version;
	u32 mac_hash1;
	u32 mac_hash2;
	u32 multicast_hash_cnt[EMAC_NUM_MULTICAST_BITS];
	u32 rx_addr_type;
	const char *phy_id;
#ifdef CONFIG_OF
	struct device_node *phy_node;
#endif
	struct phy_device *phydev;
	spinlock_t lock;
	/*platform specific members*/
	void (*int_enable) (void);
	void (*int_disable) (void);
};

/* EMAC TX Host Error description strings */
static char *emac_txhost_errcodes[16] = {
	"No error", "SOP error", "Ownership bit not set in SOP buffer",
	"Zero Next Buffer Descriptor Pointer Without EOP",
	"Zero Buffer Pointer", "Zero Buffer Length", "Packet Length Error",
	"Reserved", "Reserved", "Reserved", "Reserved", "Reserved",
	"Reserved", "Reserved", "Reserved", "Reserved"
};

/* EMAC RX Host Error description strings */
static char *emac_rxhost_errcodes[16] = {
	"No error", "Reserved", "Ownership bit not set in input buffer",
	"Reserved", "Zero Buffer Pointer", "Reserved", "Reserved",
	"Reserved", "Reserved", "Reserved", "Reserved", "Reserved",
	"Reserved", "Reserved", "Reserved", "Reserved"
};

/* Helper macros */
#define emac_read(reg)		  ioread32(priv->emac_base + (reg))
#define emac_write(reg, val)      iowrite32(val, priv->emac_base + (reg))

#define emac_ctrl_read(reg)	  ioread32((priv->ctrl_base + (reg)))
#define emac_ctrl_write(reg, val) iowrite32(val, (priv->ctrl_base + (reg)))

/**
 * emac_dump_regs - Dump important EMAC registers to debug terminal
 * @priv: The DaVinci EMAC private adapter structure
 *
 * Executes ethtool set cmd & sets phy mode
 *
 */
static void emac_dump_regs(struct emac_priv *priv)
{
	struct device *emac_dev = &priv->ndev->dev;

	/* Print important registers in EMAC */
	dev_info(emac_dev, "EMAC Basic registers\n");
	if (priv->version == EMAC_VERSION_1) {
		dev_info(emac_dev, "EMAC: EWCTL: %08X, EWINTTCNT: %08X\n",
			emac_ctrl_read(EMAC_CTRL_EWCTL),
			emac_ctrl_read(EMAC_CTRL_EWINTTCNT));
	}
	dev_info(emac_dev, "EMAC: EmuControl:%08X, FifoControl: %08X\n",
		emac_read(EMAC_EMCONTROL), emac_read(EMAC_FIFOCONTROL));
	dev_info(emac_dev, "EMAC: MBPEnable:%08X, RXUnicastSet: %08X, "\
		"RXMaxLen=%08X\n", emac_read(EMAC_RXMBPENABLE),
		emac_read(EMAC_RXUNICASTSET), emac_read(EMAC_RXMAXLEN));
	dev_info(emac_dev, "EMAC: MacControl:%08X, MacStatus: %08X, "\
		"MacConfig=%08X\n", emac_read(EMAC_MACCONTROL),
		emac_read(EMAC_MACSTATUS), emac_read(EMAC_MACCONFIG));
	dev_info(emac_dev, "EMAC Statistics\n");
	dev_info(emac_dev, "EMAC: rx_good_frames:%d\n",
		emac_read(EMAC_RXGOODFRAMES));
	dev_info(emac_dev, "EMAC: rx_broadcast_frames:%d\n",
		emac_read(EMAC_RXBCASTFRAMES));
	dev_info(emac_dev, "EMAC: rx_multicast_frames:%d\n",
		emac_read(EMAC_RXMCASTFRAMES));
	dev_info(emac_dev, "EMAC: rx_pause_frames:%d\n",
		emac_read(EMAC_RXPAUSEFRAMES));
	dev_info(emac_dev, "EMAC: rx_crcerrors:%d\n",
		emac_read(EMAC_RXCRCERRORS));
	dev_info(emac_dev, "EMAC: rx_align_code_errors:%d\n",
		emac_read(EMAC_RXALIGNCODEERRORS));
	dev_info(emac_dev, "EMAC: rx_oversized_frames:%d\n",
		emac_read(EMAC_RXOVERSIZED));
	dev_info(emac_dev, "EMAC: rx_jabber_frames:%d\n",
		emac_read(EMAC_RXJABBER));
	dev_info(emac_dev, "EMAC: rx_undersized_frames:%d\n",
		emac_read(EMAC_RXUNDERSIZED));
	dev_info(emac_dev, "EMAC: rx_fragments:%d\n",
		emac_read(EMAC_RXFRAGMENTS));
	dev_info(emac_dev, "EMAC: rx_filtered_frames:%d\n",
		emac_read(EMAC_RXFILTERED));
	dev_info(emac_dev, "EMAC: rx_qos_filtered_frames:%d\n",
		emac_read(EMAC_RXQOSFILTERED));
	dev_info(emac_dev, "EMAC: rx_octets:%d\n",
		emac_read(EMAC_RXOCTETS));
	dev_info(emac_dev, "EMAC: tx_goodframes:%d\n",
		emac_read(EMAC_TXGOODFRAMES));
	dev_info(emac_dev, "EMAC: tx_bcastframes:%d\n",
		emac_read(EMAC_TXBCASTFRAMES));
	dev_info(emac_dev, "EMAC: tx_mcastframes:%d\n",
		emac_read(EMAC_TXMCASTFRAMES));
	dev_info(emac_dev, "EMAC: tx_pause_frames:%d\n",
		emac_read(EMAC_TXPAUSEFRAMES));
	dev_info(emac_dev, "EMAC: tx_deferred_frames:%d\n",
		emac_read(EMAC_TXDEFERRED));
	dev_info(emac_dev, "EMAC: tx_collision_frames:%d\n",
		emac_read(EMAC_TXCOLLISION));
	dev_info(emac_dev, "EMAC: tx_single_coll_frames:%d\n",
		emac_read(EMAC_TXSINGLECOLL));
	dev_info(emac_dev, "EMAC: tx_mult_coll_frames:%d\n",
		emac_read(EMAC_TXMULTICOLL));
	dev_info(emac_dev, "EMAC: tx_excessive_collisions:%d\n",
		emac_read(EMAC_TXEXCESSIVECOLL));
	dev_info(emac_dev, "EMAC: tx_late_collisions:%d\n",
		emac_read(EMAC_TXLATECOLL));
	dev_info(emac_dev, "EMAC: tx_underrun:%d\n",
		emac_read(EMAC_TXUNDERRUN));
	dev_info(emac_dev, "EMAC: tx_carrier_sense_errors:%d\n",
		emac_read(EMAC_TXCARRIERSENSE));
	dev_info(emac_dev, "EMAC: tx_octets:%d\n",
		emac_read(EMAC_TXOCTETS));
	dev_info(emac_dev, "EMAC: net_octets:%d\n",
		emac_read(EMAC_NETOCTETS));
	dev_info(emac_dev, "EMAC: rx_sof_overruns:%d\n",
		emac_read(EMAC_RXSOFOVERRUNS));
	dev_info(emac_dev, "EMAC: rx_mof_overruns:%d\n",
		emac_read(EMAC_RXMOFOVERRUNS));
	dev_info(emac_dev, "EMAC: rx_dma_overruns:%d\n",
		emac_read(EMAC_RXDMAOVERRUNS));

	cpdma_ctlr_dump(priv->dma);
}

/**
 * emac_get_drvinfo - Get EMAC driver information
 * @ndev: The DaVinci EMAC network adapter
 * @info: ethtool info structure containing name and version
 *
 * Returns EMAC driver information (name and version)
 *
 */
static void emac_get_drvinfo(struct net_device *ndev,
			     struct ethtool_drvinfo *info)
{
	strlcpy(info->driver, emac_version_string, sizeof(info->driver));
	strlcpy(info->version, EMAC_MODULE_VERSION, sizeof(info->version));
}

/**
 * emac_get_settings - Get EMAC settings
 * @ndev: The DaVinci EMAC network adapter
 * @ecmd: ethtool command
 *
 * Executes ethool get command
 *
 */
static int emac_get_settings(struct net_device *ndev,
			     struct ethtool_cmd *ecmd)
{
	struct emac_priv *priv = netdev_priv(ndev);
	if (priv->phydev)
		return phy_ethtool_gset(priv->phydev, ecmd);
	else
		return -EOPNOTSUPP;

}

/**
 * emac_set_settings - Set EMAC settings
 * @ndev: The DaVinci EMAC network adapter
 * @ecmd: ethtool command
 *
 * Executes ethool set command
 *
 */
static int emac_set_settings(struct net_device *ndev, struct ethtool_cmd *ecmd)
{
	struct emac_priv *priv = netdev_priv(ndev);
	if (priv->phydev)
		return phy_ethtool_sset(priv->phydev, ecmd);
	else
		return -EOPNOTSUPP;

}

/**
 * emac_get_coalesce - Get interrupt coalesce settings for this device
 * @ndev : The DaVinci EMAC network adapter
 * @coal : ethtool coalesce settings structure
 *
 * Fetch the current interrupt coalesce settings
 *
 */
static int emac_get_coalesce(struct net_device *ndev,
				struct ethtool_coalesce *coal)
{
	struct emac_priv *priv = netdev_priv(ndev);

	coal->rx_coalesce_usecs = priv->coal_intvl;
	return 0;

}

/**
 * emac_set_coalesce - Set interrupt coalesce settings for this device
 * @ndev : The DaVinci EMAC network adapter
 * @coal : ethtool coalesce settings structure
 *
 * Set interrupt coalesce parameters
 *
 */
static int emac_set_coalesce(struct net_device *ndev,
				struct ethtool_coalesce *coal)
{
	struct emac_priv *priv = netdev_priv(ndev);
	u32 int_ctrl, num_interrupts = 0;
	u32 prescale = 0, addnl_dvdr = 1, coal_intvl = 0;

	if (!coal->rx_coalesce_usecs)
		return -EINVAL;

	coal_intvl = coal->rx_coalesce_usecs;

	switch (priv->version) {
	case EMAC_VERSION_2:
		int_ctrl =  emac_ctrl_read(EMAC_DM646X_CMINTCTRL);
		prescale = priv->bus_freq_mhz * 4;

		if (coal_intvl < EMAC_DM646X_CMINTMIN_INTVL)
			coal_intvl = EMAC_DM646X_CMINTMIN_INTVL;

		if (coal_intvl > EMAC_DM646X_CMINTMAX_INTVL) {
			/*
			 * Interrupt pacer works with 4us Pulse, we can
			 * throttle further by dilating the 4us pulse.
			 */
			addnl_dvdr = EMAC_DM646X_INTPRESCALE_MASK / prescale;

			if (addnl_dvdr > 1) {
				prescale *= addnl_dvdr;
				if (coal_intvl > (EMAC_DM646X_CMINTMAX_INTVL
							* addnl_dvdr))
					coal_intvl = (EMAC_DM646X_CMINTMAX_INTVL
							* addnl_dvdr);
			} else {
				addnl_dvdr = 1;
				coal_intvl = EMAC_DM646X_CMINTMAX_INTVL;
			}
		}

		num_interrupts = (1000 * addnl_dvdr) / coal_intvl;

		int_ctrl |= EMAC_DM646X_INTPACEEN;
		int_ctrl &= (~EMAC_DM646X_INTPRESCALE_MASK);
		int_ctrl |= (prescale & EMAC_DM646X_INTPRESCALE_MASK);
		emac_ctrl_write(EMAC_DM646X_CMINTCTRL, int_ctrl);

		emac_ctrl_write(EMAC_DM646X_CMRXINTMAX, num_interrupts);
		emac_ctrl_write(EMAC_DM646X_CMTXINTMAX, num_interrupts);

		break;
	default:
		int_ctrl = emac_ctrl_read(EMAC_CTRL_EWINTTCNT);
		int_ctrl &= (~EMAC_DM644X_EWINTCNT_MASK);
		prescale = coal_intvl * priv->bus_freq_mhz;
		if (prescale > EMAC_DM644X_EWINTCNT_MASK) {
			prescale = EMAC_DM644X_EWINTCNT_MASK;
			coal_intvl = prescale / priv->bus_freq_mhz;
		}
		emac_ctrl_write(EMAC_CTRL_EWINTTCNT, (int_ctrl | prescale));

		break;
	}

	printk(KERN_INFO"Set coalesce to %d usecs.\n", coal_intvl);
	priv->coal_intvl = coal_intvl;

	return 0;

}


/* ethtool_ops: DaVinci EMAC Ethtool structure
 *
 * Ethtool support for EMAC adapter
 */
static const struct ethtool_ops ethtool_ops = {
	.get_drvinfo = emac_get_drvinfo,
	.get_settings = emac_get_settings,
	.set_settings = emac_set_settings,
	.get_link = ethtool_op_get_link,
	.get_coalesce = emac_get_coalesce,
	.set_coalesce =  emac_set_coalesce,
	.get_ts_info = ethtool_op_get_ts_info,
};

/**
 * emac_update_phystatus - Update Phy status
 * @priv: The DaVinci EMAC private adapter structure
 *
 * Updates phy status and takes action for network queue if required
 * based upon link status
 *
 */
static void emac_update_phystatus(struct emac_priv *priv)
{
	u32 mac_control;
	u32 new_duplex;
	u32 cur_duplex;
	struct net_device *ndev = priv->ndev;

	mac_control = emac_read(EMAC_MACCONTROL);
	cur_duplex = (mac_control & EMAC_MACCONTROL_FULLDUPLEXEN) ?
			DUPLEX_FULL : DUPLEX_HALF;
	if (priv->phydev)
		new_duplex = priv->phydev->duplex;
	else
		new_duplex = DUPLEX_FULL;

	/* We get called only if link has changed (speed/duplex/status) */
	if ((priv->link) && (new_duplex != cur_duplex)) {
		priv->duplex = new_duplex;
		if (DUPLEX_FULL == priv->duplex)
			mac_control |= (EMAC_MACCONTROL_FULLDUPLEXEN);
		else
			mac_control &= ~(EMAC_MACCONTROL_FULLDUPLEXEN);
	}

	if (priv->speed == SPEED_1000 && (priv->version == EMAC_VERSION_2)) {
		mac_control = emac_read(EMAC_MACCONTROL);
		mac_control |= (EMAC_DM646X_MACCONTORL_GIG |
				EMAC_DM646X_MACCONTORL_GIGFORCE);
	} else {
		/* Clear the GIG bit and GIGFORCE bit */
		mac_control &= ~(EMAC_DM646X_MACCONTORL_GIGFORCE |
					EMAC_DM646X_MACCONTORL_GIG);

		if (priv->rmii_en && (priv->speed == SPEED_100))
			mac_control |= EMAC_MACCONTROL_RMIISPEED_MASK;
		else
			mac_control &= ~EMAC_MACCONTROL_RMIISPEED_MASK;
	}

	/* Update mac_control if changed */
	emac_write(EMAC_MACCONTROL, mac_control);

	if (priv->link) {
		/* link ON */
		if (!netif_carrier_ok(ndev))
			netif_carrier_on(ndev);
	/* reactivate the transmit queue if it is stopped */
		if (netif_running(ndev) && netif_queue_stopped(ndev))
			netif_wake_queue(ndev);
	} else {
		/* link OFF */
		if (netif_carrier_ok(ndev))
			netif_carrier_off(ndev);
		if (!netif_queue_stopped(ndev))
			netif_stop_queue(ndev);
	}
}

/**
 * hash_get - Calculate hash value from mac address
 * @addr: mac address to delete from hash table
 *
 * Calculates hash value from mac address
 *
 */
static u32 hash_get(u8 *addr)
{
	u32 hash;
	u8 tmpval;
	int cnt;
	hash = 0;

	for (cnt = 0; cnt < 2; cnt++) {
		tmpval = *addr++;
		hash ^= (tmpval >> 2) ^ (tmpval << 4);
		tmpval = *addr++;
		hash ^= (tmpval >> 4) ^ (tmpval << 2);
		tmpval = *addr++;
		hash ^= (tmpval >> 6) ^ (tmpval);
	}

	return hash & 0x3F;
}

/**
 * hash_add - Hash function to add mac addr from hash table
 * @priv: The DaVinci EMAC private adapter structure
 * @mac_addr: mac address to delete from hash table
 *
 * Adds mac address to the internal hash table
 *
 */
static int hash_add(struct emac_priv *priv, u8 *mac_addr)
{
	struct device *emac_dev = &priv->ndev->dev;
	u32 rc = 0;
	u32 hash_bit;
	u32 hash_value = hash_get(mac_addr);

	if (hash_value >= EMAC_NUM_MULTICAST_BITS) {
		if (netif_msg_drv(priv)) {
			dev_err(emac_dev, "DaVinci EMAC: hash_add(): Invalid "\
				"Hash %08x, should not be greater than %08x",
				hash_value, (EMAC_NUM_MULTICAST_BITS - 1));
		}
		return -1;
	}

	/* set the hash bit only if not previously set */
	if (priv->multicast_hash_cnt[hash_value] == 0) {
		rc = 1; /* hash value changed */
		if (hash_value < 32) {
			hash_bit = BIT(hash_value);
			priv->mac_hash1 |= hash_bit;
		} else {
			hash_bit = BIT((hash_value - 32));
			priv->mac_hash2 |= hash_bit;
		}
	}

	/* incr counter for num of mcast addr's mapped to "this" hash bit */
	++priv->multicast_hash_cnt[hash_value];

	return rc;
}

/**
 * hash_del - Hash function to delete mac addr from hash table
 * @priv: The DaVinci EMAC private adapter structure
 * @mac_addr: mac address to delete from hash table
 *
 * Removes mac address from the internal hash table
 *
 */
static int hash_del(struct emac_priv *priv, u8 *mac_addr)
{
	u32 hash_value;
	u32 hash_bit;

	hash_value = hash_get(mac_addr);
	if (priv->multicast_hash_cnt[hash_value] > 0) {
		/* dec cntr for num of mcast addr's mapped to this hash bit */
		--priv->multicast_hash_cnt[hash_value];
	}

	/* if counter still > 0, at least one multicast address refers
	 * to this hash bit. so return 0 */
	if (priv->multicast_hash_cnt[hash_value] > 0)
		return 0;

	if (hash_value < 32) {
		hash_bit = BIT(hash_value);
		priv->mac_hash1 &= ~hash_bit;
	} else {
		hash_bit = BIT((hash_value - 32));
		priv->mac_hash2 &= ~hash_bit;
	}

	/* return 1 to indicate change in mac_hash registers reqd */
	return 1;
}

/* EMAC multicast operation */
#define EMAC_MULTICAST_ADD	0
#define EMAC_MULTICAST_DEL	1
#define EMAC_ALL_MULTI_SET	2
#define EMAC_ALL_MULTI_CLR	3

/**
 * emac_add_mcast - Set multicast address in the EMAC adapter (Internal)
 * @priv: The DaVinci EMAC private adapter structure
 * @action: multicast operation to perform
 * mac_addr: mac address to set
 *
 * Set multicast addresses in EMAC adapter - internal function
 *
 */
static void emac_add_mcast(struct emac_priv *priv, u32 action, u8 *mac_addr)
{
	struct device *emac_dev = &priv->ndev->dev;
	int update = -1;

	switch (action) {
	case EMAC_MULTICAST_ADD:
		update = hash_add(priv, mac_addr);
		break;
	case EMAC_MULTICAST_DEL:
		update = hash_del(priv, mac_addr);
		break;
	case EMAC_ALL_MULTI_SET:
		update = 1;
		priv->mac_hash1 = EMAC_ALL_MULTI_REG_VALUE;
		priv->mac_hash2 = EMAC_ALL_MULTI_REG_VALUE;
		break;
	case EMAC_ALL_MULTI_CLR:
		update = 1;
		priv->mac_hash1 = 0;
		priv->mac_hash2 = 0;
		memset(&(priv->multicast_hash_cnt[0]), 0,
		sizeof(priv->multicast_hash_cnt[0]) *
		       EMAC_NUM_MULTICAST_BITS);
		break;
	default:
		if (netif_msg_drv(priv))
			dev_err(emac_dev, "DaVinci EMAC: add_mcast"\
				": bad operation %d", action);
		break;
	}

	/* write to the hardware only if the register status chances */
	if (update > 0) {
		emac_write(EMAC_MACHASH1, priv->mac_hash1);
		emac_write(EMAC_MACHASH2, priv->mac_hash2);
	}
}

/**
 * emac_dev_mcast_set - Set multicast address in the EMAC adapter
 * @ndev: The DaVinci EMAC network adapter
 *
 * Set multicast addresses in EMAC adapter
 *
 */
static void emac_dev_mcast_set(struct net_device *ndev)
{
	u32 mbp_enable;
	struct emac_priv *priv = netdev_priv(ndev);

	mbp_enable = emac_read(EMAC_RXMBPENABLE);
	if (ndev->flags & IFF_PROMISC) {
		mbp_enable &= (~EMAC_MBP_PROMISCCH(EMAC_DEF_PROM_CH));
		mbp_enable |= (EMAC_MBP_RXPROMISC);
	} else {
		mbp_enable = (mbp_enable & ~EMAC_MBP_RXPROMISC);
		if ((ndev->flags & IFF_ALLMULTI) ||
		    netdev_mc_count(ndev) > EMAC_DEF_MAX_MULTICAST_ADDRESSES) {
			mbp_enable = (mbp_enable | EMAC_MBP_RXMCAST);
			emac_add_mcast(priv, EMAC_ALL_MULTI_SET, NULL);
		}
		if (!netdev_mc_empty(ndev)) {
			struct netdev_hw_addr *ha;

			mbp_enable = (mbp_enable | EMAC_MBP_RXMCAST);
			emac_add_mcast(priv, EMAC_ALL_MULTI_CLR, NULL);
			/* program multicast address list into EMAC hardware */
			netdev_for_each_mc_addr(ha, ndev) {
				emac_add_mcast(priv, EMAC_MULTICAST_ADD,
					       (u8 *) ha->addr);
			}
		} else {
			mbp_enable = (mbp_enable & ~EMAC_MBP_RXMCAST);
			emac_add_mcast(priv, EMAC_ALL_MULTI_CLR, NULL);
		}
	}
	/* Set mbp config register */
	emac_write(EMAC_RXMBPENABLE, mbp_enable);
}

/*************************************************************************
 *  EMAC Hardware manipulation
 *************************************************************************/

/**
 * emac_int_disable - Disable EMAC module interrupt (from adapter)
 * @priv: The DaVinci EMAC private adapter structure
 *
 * Disable EMAC interrupt on the adapter
 *
 */
static void emac_int_disable(struct emac_priv *priv)
{
	if (priv->version == EMAC_VERSION_2) {
		unsigned long flags;

		local_irq_save(flags);

		/* Program C0_Int_En to zero to turn off
		* interrupts to the CPU */
		emac_ctrl_write(EMAC_DM646X_CMRXINTEN, 0x0);
		emac_ctrl_write(EMAC_DM646X_CMTXINTEN, 0x0);
		/* NOTE: Rx Threshold and Misc interrupts are not disabled */
		if (priv->int_disable)
			priv->int_disable();

		local_irq_restore(flags);

	} else {
		/* Set DM644x control registers for interrupt control */
		emac_ctrl_write(EMAC_CTRL_EWCTL, 0x0);
	}
}

/**
 * emac_int_enable - Enable EMAC module interrupt (from adapter)
 * @priv: The DaVinci EMAC private adapter structure
 *
 * Enable EMAC interrupt on the adapter
 *
 */
static void emac_int_enable(struct emac_priv *priv)
{
	if (priv->version == EMAC_VERSION_2) {
		if (priv->int_enable)
			priv->int_enable();

		emac_ctrl_write(EMAC_DM646X_CMRXINTEN, 0xff);
		emac_ctrl_write(EMAC_DM646X_CMTXINTEN, 0xff);

		/* In addition to turning on interrupt Enable, we need
		 * ack by writing appropriate values to the EOI
		 * register */

		/* NOTE: Rx Threshold and Misc interrupts are not enabled */

		/* ack rxen only then a new pulse will be generated */
		emac_write(EMAC_DM646X_MACEOIVECTOR,
			EMAC_DM646X_MAC_EOI_C0_RXEN);

		/* ack txen- only then a new pulse will be generated */
		emac_write(EMAC_DM646X_MACEOIVECTOR,
			EMAC_DM646X_MAC_EOI_C0_TXEN);

	} else {
		/* Set DM644x control registers for interrupt control */
		emac_ctrl_write(EMAC_CTRL_EWCTL, 0x1);
	}
}

/**
 * emac_irq - EMAC interrupt handler
 * @irq: interrupt number
 * @dev_id: EMAC network adapter data structure ptr
 *
 * EMAC Interrupt handler - we only schedule NAPI and not process any packets
 * here. EVen the interrupt status is checked (TX/RX/Err) in NAPI poll function
 *
 * Returns interrupt handled condition
 */
static irqreturn_t emac_irq(int irq, void *dev_id)
{
	struct net_device *ndev = (struct net_device *)dev_id;
	struct emac_priv *priv = netdev_priv(ndev);

	++priv->isr_count;
	if (likely(netif_running(priv->ndev))) {
		emac_int_disable(priv);
		napi_schedule(&priv->napi);
	} else {
		/* we are closing down, so dont process anything */
	}
	return IRQ_HANDLED;
}

static struct sk_buff *emac_rx_alloc(struct emac_priv *priv)
{
	struct sk_buff *skb = netdev_alloc_skb(priv->ndev, priv->rx_buf_size);
	if (WARN_ON(!skb))
		return NULL;
	skb_reserve(skb, NET_IP_ALIGN);
	return skb;
}

static void emac_rx_handler(void *token, int len, int status)
{
	struct sk_buff		*skb = token;
	struct net_device	*ndev = skb->dev;
	struct emac_priv	*priv = netdev_priv(ndev);
	struct device		*emac_dev = &ndev->dev;
	int			ret;

	/* free and bail if we are shutting down */
	if (unlikely(!netif_running(ndev))) {
		dev_kfree_skb_any(skb);
		return;
	}

	/* recycle on receive error */
	if (status < 0) {
		ndev->stats.rx_errors++;
		goto recycle;
	}

	/* feed received packet up the stack */
	skb_put(skb, len);
	skb->protocol = eth_type_trans(skb, ndev);
	netif_receive_skb(skb);
	ndev->stats.rx_bytes += len;
	ndev->stats.rx_packets++;

	/* alloc a new packet for receive */
	skb = emac_rx_alloc(priv);
	if (!skb) {
		if (netif_msg_rx_err(priv) && net_ratelimit())
			dev_err(emac_dev, "failed rx buffer alloc\n");
		return;
	}

recycle:
	ret = cpdma_chan_submit(priv->rxchan, skb, skb->data,
			skb_tailroom(skb), 0, GFP_KERNEL);

	WARN_ON(ret == -ENOMEM);
	if (unlikely(ret < 0))
		dev_kfree_skb_any(skb);
}

static void emac_tx_handler(void *token, int len, int status)
{
	struct sk_buff		*skb = token;
	struct net_device	*ndev = skb->dev;

	/* Check whether the queue is stopped due to stalled tx dma, if the
	 * queue is stopped then start the queue as we have free desc for tx
	 */
	if (unlikely(netif_queue_stopped(ndev)))
		netif_start_queue(ndev);
	ndev->stats.tx_packets++;
	ndev->stats.tx_bytes += len;
	dev_kfree_skb_any(skb);
}

/**
 * emac_dev_xmit - EMAC Transmit function
 * @skb: SKB pointer
 * @ndev: The DaVinci EMAC network adapter
 *
 * Called by the system to transmit a packet  - we queue the packet in
 * EMAC hardware transmit queue
 *
 * Returns success(NETDEV_TX_OK) or error code (typically out of desc's)
 */
static int emac_dev_xmit(struct sk_buff *skb, struct net_device *ndev)
{
	struct device *emac_dev = &ndev->dev;
	int ret_code;
	struct emac_priv *priv = netdev_priv(ndev);

	/* If no link, return */
	if (unlikely(!priv->link)) {
		if (netif_msg_tx_err(priv) && net_ratelimit())
			dev_err(emac_dev, "DaVinci EMAC: No link to transmit");
		goto fail_tx;
	}

	ret_code = skb_padto(skb, EMAC_DEF_MIN_ETHPKTSIZE);
	if (unlikely(ret_code < 0)) {
		if (netif_msg_tx_err(priv) && net_ratelimit())
			dev_err(emac_dev, "DaVinci EMAC: packet pad failed");
		goto fail_tx;
	}

	skb_tx_timestamp(skb);

	ret_code = cpdma_chan_submit(priv->txchan, skb, skb->data, skb->len,
				     0, GFP_KERNEL);
	if (unlikely(ret_code != 0)) {
		if (netif_msg_tx_err(priv) && net_ratelimit())
			dev_err(emac_dev, "DaVinci EMAC: desc submit failed");
		goto fail_tx;
	}

	/* If there is no more tx desc left free then we need to
	 * tell the kernel to stop sending us tx frames.
	 */
	if (unlikely(!cpdma_check_free_tx_desc(priv->txchan)))
		netif_stop_queue(ndev);

	return NETDEV_TX_OK;

fail_tx:
	ndev->stats.tx_dropped++;
	netif_stop_queue(ndev);
	return NETDEV_TX_BUSY;
}

/**
 * emac_dev_tx_timeout - EMAC Transmit timeout function
 * @ndev: The DaVinci EMAC network adapter
 *
 * Called when system detects that a skb timeout period has expired
 * potentially due to a fault in the adapter in not being able to send
 * it out on the wire. We teardown the TX channel assuming a hardware
 * error and re-initialize the TX channel for hardware operation
 *
 */
static void emac_dev_tx_timeout(struct net_device *ndev)
{
	struct emac_priv *priv = netdev_priv(ndev);
	struct device *emac_dev = &ndev->dev;

	if (netif_msg_tx_err(priv))
		dev_err(emac_dev, "DaVinci EMAC: xmit timeout, restarting TX");

	emac_dump_regs(priv);

	ndev->stats.tx_errors++;
	emac_int_disable(priv);
	cpdma_chan_stop(priv->txchan);
	cpdma_chan_start(priv->txchan);
	emac_int_enable(priv);
}

/**
 * emac_set_type0addr - Set EMAC Type0 mac address
 * @priv: The DaVinci EMAC private adapter structure
 * @ch: RX channel number
 * @mac_addr: MAC address to set in device
 *
 * Called internally to set Type0 mac address of the adapter (Device)
 *
 * Returns success (0) or appropriate error code (none as of now)
 */
static void emac_set_type0addr(struct emac_priv *priv, u32 ch, char *mac_addr)
{
	u32 val;
	val = ((mac_addr[5] << 8) | (mac_addr[4]));
	emac_write(EMAC_MACSRCADDRLO, val);

	val = ((mac_addr[3] << 24) | (mac_addr[2] << 16) | \
	       (mac_addr[1] << 8) | (mac_addr[0]));
	emac_write(EMAC_MACSRCADDRHI, val);
	val = emac_read(EMAC_RXUNICASTSET);
	val |= BIT(ch);
	emac_write(EMAC_RXUNICASTSET, val);
	val = emac_read(EMAC_RXUNICASTCLEAR);
	val &= ~BIT(ch);
	emac_write(EMAC_RXUNICASTCLEAR, val);
}

/**
 * emac_set_type1addr - Set EMAC Type1 mac address
 * @priv: The DaVinci EMAC private adapter structure
 * @ch: RX channel number
 * @mac_addr: MAC address to set in device
 *
 * Called internally to set Type1 mac address of the adapter (Device)
 *
 * Returns success (0) or appropriate error code (none as of now)
 */
static void emac_set_type1addr(struct emac_priv *priv, u32 ch, char *mac_addr)
{
	u32 val;
	emac_write(EMAC_MACINDEX, ch);
	val = ((mac_addr[5] << 8) | mac_addr[4]);
	emac_write(EMAC_MACADDRLO, val);
	val = ((mac_addr[3] << 24) | (mac_addr[2] << 16) | \
	       (mac_addr[1] << 8) | (mac_addr[0]));
	emac_write(EMAC_MACADDRHI, val);
	emac_set_type0addr(priv, ch, mac_addr);
}

/**
 * emac_set_type2addr - Set EMAC Type2 mac address
 * @priv: The DaVinci EMAC private adapter structure
 * @ch: RX channel number
 * @mac_addr: MAC address to set in device
 * @index: index into RX address entries
 * @match: match parameter for RX address matching logic
 *
 * Called internally to set Type2 mac address of the adapter (Device)
 *
 * Returns success (0) or appropriate error code (none as of now)
 */
static void emac_set_type2addr(struct emac_priv *priv, u32 ch,
			       char *mac_addr, int index, int match)
{
	u32 val;
	emac_write(EMAC_MACINDEX, index);
	val = ((mac_addr[3] << 24) | (mac_addr[2] << 16) | \
	       (mac_addr[1] << 8) | (mac_addr[0]));
	emac_write(EMAC_MACADDRHI, val);
	val = ((mac_addr[5] << 8) | mac_addr[4] | ((ch & 0x7) << 16) | \
	       (match << 19) | BIT(20));
	emac_write(EMAC_MACADDRLO, val);
	emac_set_type0addr(priv, ch, mac_addr);
}

/**
 * emac_setmac - Set mac address in the adapter (internal function)
 * @priv: The DaVinci EMAC private adapter structure
 * @ch: RX channel number
 * @mac_addr: MAC address to set in device
 *
 * Called internally to set the mac address of the adapter (Device)
 *
 * Returns success (0) or appropriate error code (none as of now)
 */
static void emac_setmac(struct emac_priv *priv, u32 ch, char *mac_addr)
{
	struct device *emac_dev = &priv->ndev->dev;

	if (priv->rx_addr_type == 0) {
		emac_set_type0addr(priv, ch, mac_addr);
	} else if (priv->rx_addr_type == 1) {
		u32 cnt;
		for (cnt = 0; cnt < EMAC_MAX_TXRX_CHANNELS; cnt++)
			emac_set_type1addr(priv, ch, mac_addr);
	} else if (priv->rx_addr_type == 2) {
		emac_set_type2addr(priv, ch, mac_addr, ch, 1);
		emac_set_type0addr(priv, ch, mac_addr);
	} else {
		if (netif_msg_drv(priv))
			dev_err(emac_dev, "DaVinci EMAC: Wrong addressing\n");
	}
}

/**
 * emac_dev_setmac_addr - Set mac address in the adapter
 * @ndev: The DaVinci EMAC network adapter
 * @addr: MAC address to set in device
 *
 * Called by the system to set the mac address of the adapter (Device)
 *
 * Returns success (0) or appropriate error code (none as of now)
 */
static int emac_dev_setmac_addr(struct net_device *ndev, void *addr)
{
	struct emac_priv *priv = netdev_priv(ndev);
	struct device *emac_dev = &priv->ndev->dev;
	struct sockaddr *sa = addr;

	if (!is_valid_ether_addr(sa->sa_data))
		return -EADDRNOTAVAIL;

	/* Store mac addr in priv and rx channel and set it in EMAC hw */
	memcpy(priv->mac_addr, sa->sa_data, ndev->addr_len);
	memcpy(ndev->dev_addr, sa->sa_data, ndev->addr_len);

	/* MAC address is configured only after the interface is enabled. */
	if (netif_running(ndev)) {
		emac_setmac(priv, EMAC_DEF_RX_CH, priv->mac_addr);
	}

	if (netif_msg_drv(priv))
		dev_notice(emac_dev, "DaVinci EMAC: emac_dev_setmac_addr %pM\n",
					priv->mac_addr);

	return 0;
}

/**
 * emac_hw_enable - Enable EMAC hardware for packet transmission/reception
 * @priv: The DaVinci EMAC private adapter structure
 *
 * Enables EMAC hardware for packet processing - enables PHY, enables RX
 * for packet reception and enables device interrupts and then NAPI
 *
 * Returns success (0) or appropriate error code (none right now)
 */
static int emac_hw_enable(struct emac_priv *priv)
{
	u32 val, mbp_enable, mac_control;

	/* Soft reset */
	emac_write(EMAC_SOFTRESET, 1);
	while (emac_read(EMAC_SOFTRESET))
		cpu_relax();

	/* Disable interrupt & Set pacing for more interrupts initially */
	emac_int_disable(priv);

	/* Full duplex enable bit set when auto negotiation happens */
	mac_control =
		(((EMAC_DEF_TXPRIO_FIXED) ? (EMAC_MACCONTROL_TXPTYPE) : 0x0) |
		((priv->speed == 1000) ? EMAC_MACCONTROL_GIGABITEN : 0x0) |
		((EMAC_DEF_TXPACING_EN) ? (EMAC_MACCONTROL_TXPACEEN) : 0x0) |
		((priv->duplex == DUPLEX_FULL) ? 0x1 : 0));
	emac_write(EMAC_MACCONTROL, mac_control);

	mbp_enable =
		(((EMAC_DEF_PASS_CRC) ? (EMAC_RXMBP_PASSCRC_MASK) : 0x0) |
		((EMAC_DEF_QOS_EN) ? (EMAC_RXMBP_QOSEN_MASK) : 0x0) |
		 ((EMAC_DEF_NO_BUFF_CHAIN) ? (EMAC_RXMBP_NOCHAIN_MASK) : 0x0) |
		 ((EMAC_DEF_MACCTRL_FRAME_EN) ? (EMAC_RXMBP_CMFEN_MASK) : 0x0) |
		 ((EMAC_DEF_SHORT_FRAME_EN) ? (EMAC_RXMBP_CSFEN_MASK) : 0x0) |
		 ((EMAC_DEF_ERROR_FRAME_EN) ? (EMAC_RXMBP_CEFEN_MASK) : 0x0) |
		 ((EMAC_DEF_PROM_EN) ? (EMAC_RXMBP_CAFEN_MASK) : 0x0) |
		 ((EMAC_DEF_PROM_CH & EMAC_RXMBP_CHMASK) << \
			EMAC_RXMBP_PROMCH_SHIFT) |
		 ((EMAC_DEF_BCAST_EN) ? (EMAC_RXMBP_BROADEN_MASK) : 0x0) |
		 ((EMAC_DEF_BCAST_CH & EMAC_RXMBP_CHMASK) << \
			EMAC_RXMBP_BROADCH_SHIFT) |
		 ((EMAC_DEF_MCAST_EN) ? (EMAC_RXMBP_MULTIEN_MASK) : 0x0) |
		 ((EMAC_DEF_MCAST_CH & EMAC_RXMBP_CHMASK) << \
			EMAC_RXMBP_MULTICH_SHIFT));
	emac_write(EMAC_RXMBPENABLE, mbp_enable);
	emac_write(EMAC_RXMAXLEN, (EMAC_DEF_MAX_FRAME_SIZE &
				   EMAC_RX_MAX_LEN_MASK));
	emac_write(EMAC_RXBUFFEROFFSET, (EMAC_DEF_BUFFER_OFFSET &
					 EMAC_RX_BUFFER_OFFSET_MASK));
	emac_write(EMAC_RXFILTERLOWTHRESH, 0);
	emac_write(EMAC_RXUNICASTCLEAR, EMAC_RX_UNICAST_CLEAR_ALL);
	priv->rx_addr_type = (emac_read(EMAC_MACCONFIG) >> 8) & 0xFF;

	emac_write(EMAC_MACINTMASKSET, EMAC_MAC_HOST_ERR_INTMASK_VAL);

	emac_setmac(priv, EMAC_DEF_RX_CH, priv->mac_addr);

	/* Enable MII */
	val = emac_read(EMAC_MACCONTROL);
	val |= (EMAC_MACCONTROL_GMIIEN);
	emac_write(EMAC_MACCONTROL, val);

	/* Enable NAPI and interrupts */
	napi_enable(&priv->napi);
	emac_int_enable(priv);
	return 0;

}

/**
 * emac_poll - EMAC NAPI Poll function
 * @ndev: The DaVinci EMAC network adapter
 * @budget: Number of receive packets to process (as told by NAPI layer)
 *
 * NAPI Poll function implemented to process packets as per budget. We check
 * the type of interrupt on the device and accordingly call the TX or RX
 * packet processing functions. We follow the budget for RX processing and
 * also put a cap on number of TX pkts processed through config param. The
 * NAPI schedule function is called if more packets pending.
 *
 * Returns number of packets received (in most cases; else TX pkts - rarely)
 */
static int emac_poll(struct napi_struct *napi, int budget)
{
	unsigned int mask;
	struct emac_priv *priv = container_of(napi, struct emac_priv, napi);
	struct net_device *ndev = priv->ndev;
	struct device *emac_dev = &ndev->dev;
	u32 status = 0;
	u32 num_tx_pkts = 0, num_rx_pkts = 0;

	/* Check interrupt vectors and call packet processing */
	status = emac_read(EMAC_MACINVECTOR);

	mask = EMAC_DM644X_MAC_IN_VECTOR_TX_INT_VEC;

	if (priv->version == EMAC_VERSION_2)
		mask = EMAC_DM646X_MAC_IN_VECTOR_TX_INT_VEC;

	if (status & mask) {
		num_tx_pkts = cpdma_chan_process(priv->txchan,
					      EMAC_DEF_TX_MAX_SERVICE);
	} /* TX processing */

	mask = EMAC_DM644X_MAC_IN_VECTOR_RX_INT_VEC;

	if (priv->version == EMAC_VERSION_2)
		mask = EMAC_DM646X_MAC_IN_VECTOR_RX_INT_VEC;

	if (status & mask) {
		num_rx_pkts = cpdma_chan_process(priv->rxchan, budget);
	} /* RX processing */

	mask = EMAC_DM644X_MAC_IN_VECTOR_HOST_INT;
	if (priv->version == EMAC_VERSION_2)
		mask = EMAC_DM646X_MAC_IN_VECTOR_HOST_INT;

	if (unlikely(status & mask)) {
		u32 ch, cause;
		dev_err(emac_dev, "DaVinci EMAC: Fatal Hardware Error\n");
		netif_stop_queue(ndev);
		napi_disable(&priv->napi);

		status = emac_read(EMAC_MACSTATUS);
		cause = ((status & EMAC_MACSTATUS_TXERRCODE_MASK) >>
			 EMAC_MACSTATUS_TXERRCODE_SHIFT);
		if (cause) {
			ch = ((status & EMAC_MACSTATUS_TXERRCH_MASK) >>
			      EMAC_MACSTATUS_TXERRCH_SHIFT);
			if (net_ratelimit()) {
				dev_err(emac_dev, "TX Host error %s on ch=%d\n",
					&emac_txhost_errcodes[cause][0], ch);
			}
		}
		cause = ((status & EMAC_MACSTATUS_RXERRCODE_MASK) >>
			 EMAC_MACSTATUS_RXERRCODE_SHIFT);
		if (cause) {
			ch = ((status & EMAC_MACSTATUS_RXERRCH_MASK) >>
			      EMAC_MACSTATUS_RXERRCH_SHIFT);
			if (netif_msg_hw(priv) && net_ratelimit())
				dev_err(emac_dev, "RX Host error %s on ch=%d\n",
					&emac_rxhost_errcodes[cause][0], ch);
		}
	} else if (num_rx_pkts < budget) {
		napi_complete(napi);
		emac_int_enable(priv);
	}

	return num_rx_pkts;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/**
 * emac_poll_controller - EMAC Poll controller function
 * @ndev: The DaVinci EMAC network adapter
 *
 * Polled functionality used by netconsole and others in non interrupt mode
 *
 */
void emac_poll_controller(struct net_device *ndev)
{
	struct emac_priv *priv = netdev_priv(ndev);

	emac_int_disable(priv);
	emac_irq(ndev->irq, ndev);
	emac_int_enable(priv);
}
#endif

static void emac_adjust_link(struct net_device *ndev)
{
	struct emac_priv *priv = netdev_priv(ndev);
	struct phy_device *phydev = priv->phydev;
	unsigned long flags;
	int new_state = 0;

	spin_lock_irqsave(&priv->lock, flags);

	if (phydev->link) {
		/* check the mode of operation - full/half duplex */
		if (phydev->duplex != priv->duplex) {
			new_state = 1;
			priv->duplex = phydev->duplex;
		}
		if (phydev->speed != priv->speed) {
			new_state = 1;
			priv->speed = phydev->speed;
		}
		if (!priv->link) {
			new_state = 1;
			priv->link = 1;
		}

	} else if (priv->link) {
		new_state = 1;
		priv->link = 0;
		priv->speed = 0;
		priv->duplex = ~0;
	}
	if (new_state) {
		emac_update_phystatus(priv);
		phy_print_status(priv->phydev);
	}

	spin_unlock_irqrestore(&priv->lock, flags);
}

/*************************************************************************
 *  Linux Driver Model
 *************************************************************************/

/**
 * emac_devioctl - EMAC adapter ioctl
 * @ndev: The DaVinci EMAC network adapter
 * @ifrq: request parameter
 * @cmd: command parameter
 *
 * EMAC driver ioctl function
 *
 * Returns success(0) or appropriate error code
 */
static int emac_devioctl(struct net_device *ndev, struct ifreq *ifrq, int cmd)
{
	struct emac_priv *priv = netdev_priv(ndev);

	if (!(netif_running(ndev)))
		return -EINVAL;

	/* TODO: Add phy read and write and private statistics get feature */

	return phy_mii_ioctl(priv->phydev, ifrq, cmd);
}

static int match_first_device(struct device *dev, void *data)
{
	return !strncmp(dev_name(dev), "davinci_mdio", 12);
}

/**
 * emac_dev_open - EMAC device open
 * @ndev: The DaVinci EMAC network adapter
 *
 * Called when system wants to start the interface. We init TX/RX channels
 * and enable the hardware for packet reception/transmission and start the
 * network queue.
 *
 * Returns 0 for a successful open, or appropriate error code
 */
static int emac_dev_open(struct net_device *ndev)
{
	struct device *emac_dev = &ndev->dev;
	u32 cnt;
	struct resource *res;
	int q, m, ret;
	int i = 0;
	int k = 0;
	struct emac_priv *priv = netdev_priv(ndev);

	pm_runtime_get(&priv->pdev->dev);

	netif_carrier_off(ndev);
	for (cnt = 0; cnt < ETH_ALEN; cnt++)
		ndev->dev_addr[cnt] = priv->mac_addr[cnt];

	/* Configuration items */
	priv->rx_buf_size = EMAC_DEF_MAX_FRAME_SIZE + NET_IP_ALIGN;

	priv->mac_hash1 = 0;
	priv->mac_hash2 = 0;
	emac_write(EMAC_MACHASH1, 0);
	emac_write(EMAC_MACHASH2, 0);

	for (i = 0; i < EMAC_DEF_RX_NUM_DESC; i++) {
		struct sk_buff *skb = emac_rx_alloc(priv);

		if (!skb)
			break;

		ret = cpdma_chan_submit(priv->rxchan, skb, skb->data,
					skb_tailroom(skb), 0, GFP_KERNEL);
		if (WARN_ON(ret < 0))
			break;
	}

	/* Request IRQ */

	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k))) {
		for (i = res->start; i <= res->end; i++) {
			if (request_irq(i, emac_irq, IRQF_DISABLED,
					ndev->name, ndev))
				goto rollback;
		}
		k++;
	}

	/* Start/Enable EMAC hardware */
	emac_hw_enable(priv);

	/* Enable Interrupt pacing if configured */
	if (priv->coal_intvl != 0) {
		struct ethtool_coalesce coal;

		coal.rx_coalesce_usecs = (priv->coal_intvl << 4);
		emac_set_coalesce(ndev, &coal);
	}

	cpdma_ctlr_start(priv->dma);

	priv->phydev = NULL;
	/* use the first phy on the bus if pdata did not give us a phy id */
	if (!priv->phy_id) {
		struct device *phy;

		phy = bus_find_device(&mdio_bus_type, NULL, NULL,
				      match_first_device);
		if (phy)
			priv->phy_id = dev_name(phy);
	}

	if (priv->phy_id && *priv->phy_id) {
		priv->phydev = phy_connect(ndev, priv->phy_id,
					   &emac_adjust_link,
					   PHY_INTERFACE_MODE_MII);

		if (IS_ERR(priv->phydev)) {
			dev_err(emac_dev, "could not connect to phy %s\n",
				priv->phy_id);
			ret = PTR_ERR(priv->phydev);
			priv->phydev = NULL;
			goto err;
		}

		priv->link = 0;
		priv->speed = 0;
		priv->duplex = ~0;

		dev_info(emac_dev, "attached PHY driver [%s] "
			"(mii_bus:phy_addr=%s, id=%x)\n",
			priv->phydev->drv->name, dev_name(&priv->phydev->dev),
			priv->phydev->phy_id);
	} else {
		/* No PHY , fix the link, speed and duplex settings */
		dev_notice(emac_dev, "no phy, defaulting to 100/full\n");
		priv->link = 1;
		priv->speed = SPEED_100;
		priv->duplex = DUPLEX_FULL;
		emac_update_phystatus(priv);
	}

	if (!netif_running(ndev)) /* debug only - to avoid compiler warning */
		emac_dump_regs(priv);

	if (netif_msg_drv(priv))
		dev_notice(emac_dev, "DaVinci EMAC: Opened %s\n", ndev->name);

	if (priv->phydev)
		phy_start(priv->phydev);

	return 0;

rollback:

	dev_err(emac_dev, "DaVinci EMAC: request_irq() failed");

	for (q = k; k >= 0; k--) {
		for (m = i; m >= res->start; m--)
			free_irq(m, ndev);
		res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, k-1);
		m = res->end;
	}

	ret = -EBUSY;
err:
	pm_runtime_put(&priv->pdev->dev);
	return ret;
}

/**
 * emac_dev_stop - EMAC device stop
 * @ndev: The DaVinci EMAC network adapter
 *
 * Called when system wants to stop or down the interface. We stop the network
 * queue, disable interrupts and cleanup TX/RX channels.
 *
 * We return the statistics in net_device_stats structure pulled from emac
 */
static int emac_dev_stop(struct net_device *ndev)
{
	struct resource *res;
	int i = 0;
	int irq_num;
	struct emac_priv *priv = netdev_priv(ndev);
	struct device *emac_dev = &ndev->dev;

	/* inform the upper layers. */
	netif_stop_queue(ndev);
	napi_disable(&priv->napi);

	netif_carrier_off(ndev);
	emac_int_disable(priv);
	cpdma_ctlr_stop(priv->dma);
	emac_write(EMAC_SOFTRESET, 1);

	if (priv->phydev)
		phy_disconnect(priv->phydev);

	/* Free IRQ */
	while ((res = platform_get_resource(priv->pdev, IORESOURCE_IRQ, i))) {
		for (irq_num = res->start; irq_num <= res->end; irq_num++)
			free_irq(irq_num, priv->ndev);
		i++;
	}

	if (netif_msg_drv(priv))
		dev_notice(emac_dev, "DaVinci EMAC: %s stopped\n", ndev->name);

	pm_runtime_put(&priv->pdev->dev);
	return 0;
}

/**
 * emac_dev_getnetstats - EMAC get statistics function
 * @ndev: The DaVinci EMAC network adapter
 *
 * Called when system wants to get statistics from the device.
 *
 * We return the statistics in net_device_stats structure pulled from emac
 */
static struct net_device_stats *emac_dev_getnetstats(struct net_device *ndev)
{
	struct emac_priv *priv = netdev_priv(ndev);
	u32 mac_control;
	u32 stats_clear_mask;

	/* update emac hardware stats and reset the registers*/

	mac_control = emac_read(EMAC_MACCONTROL);

	if (mac_control & EMAC_MACCONTROL_GMIIEN)
		stats_clear_mask = EMAC_STATS_CLR_MASK;
	else
		stats_clear_mask = 0;

	ndev->stats.multicast += emac_read(EMAC_RXMCASTFRAMES);
	emac_write(EMAC_RXMCASTFRAMES, stats_clear_mask);

	ndev->stats.collisions += (emac_read(EMAC_TXCOLLISION) +
					   emac_read(EMAC_TXSINGLECOLL) +
					   emac_read(EMAC_TXMULTICOLL));
	emac_write(EMAC_TXCOLLISION, stats_clear_mask);
	emac_write(EMAC_TXSINGLECOLL, stats_clear_mask);
	emac_write(EMAC_TXMULTICOLL, stats_clear_mask);

	ndev->stats.rx_length_errors += (emac_read(EMAC_RXOVERSIZED) +
						emac_read(EMAC_RXJABBER) +
						emac_read(EMAC_RXUNDERSIZED));
	emac_write(EMAC_RXOVERSIZED, stats_clear_mask);
	emac_write(EMAC_RXJABBER, stats_clear_mask);
	emac_write(EMAC_RXUNDERSIZED, stats_clear_mask);

	ndev->stats.rx_over_errors += (emac_read(EMAC_RXSOFOVERRUNS) +
					       emac_read(EMAC_RXMOFOVERRUNS));
	emac_write(EMAC_RXSOFOVERRUNS, stats_clear_mask);
	emac_write(EMAC_RXMOFOVERRUNS, stats_clear_mask);

	ndev->stats.rx_fifo_errors += emac_read(EMAC_RXDMAOVERRUNS);
	emac_write(EMAC_RXDMAOVERRUNS, stats_clear_mask);

	ndev->stats.tx_carrier_errors +=
		emac_read(EMAC_TXCARRIERSENSE);
	emac_write(EMAC_TXCARRIERSENSE, stats_clear_mask);

	ndev->stats.tx_fifo_errors += emac_read(EMAC_TXUNDERRUN);
	emac_write(EMAC_TXUNDERRUN, stats_clear_mask);

	return &ndev->stats;
}

static const struct net_device_ops emac_netdev_ops = {
	.ndo_open		= emac_dev_open,
	.ndo_stop		= emac_dev_stop,
	.ndo_start_xmit		= emac_dev_xmit,
	.ndo_set_rx_mode	= emac_dev_mcast_set,
	.ndo_set_mac_address	= emac_dev_setmac_addr,
	.ndo_do_ioctl		= emac_devioctl,
	.ndo_tx_timeout		= emac_dev_tx_timeout,
	.ndo_get_stats		= emac_dev_getnetstats,
#ifdef CONFIG_NET_POLL_CONTROLLER
	.ndo_poll_controller	= emac_poll_controller,
#endif
};

#ifdef CONFIG_OF
static struct emac_platform_data
	*davinci_emac_of_get_pdata(struct platform_device *pdev,
	struct emac_priv *priv)
{
	struct device_node *np;
	struct emac_platform_data *pdata = NULL;
	const u8 *mac_addr;
	u32 data;
	int ret;

	pdata = pdev->dev.platform_data;
	if (!pdata) {
		pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
		if (!pdata)
			goto nodata;
	}

	np = pdev->dev.of_node;
	if (!np)
		goto nodata;
	else
		pdata->version = EMAC_VERSION_2;

	if (!is_valid_ether_addr(pdata->mac_addr)) {
		mac_addr = of_get_mac_address(np);
		if (mac_addr)
			memcpy(pdata->mac_addr, mac_addr, ETH_ALEN);
	}

	ret = of_property_read_u32(np, "ti,davinci-ctrl-reg-offset", &data);
	if (!ret)
		pdata->ctrl_reg_offset = data;

	ret = of_property_read_u32(np, "ti,davinci-ctrl-mod-reg-offset",
		&data);
	if (!ret)
		pdata->ctrl_mod_reg_offset = data;

	ret = of_property_read_u32(np, "ti,davinci-ctrl-ram-offset", &data);
	if (!ret)
		pdata->ctrl_ram_offset = data;

	ret = of_property_read_u32(np, "ti,davinci-ctrl-ram-size", &data);
	if (!ret)
		pdata->ctrl_ram_size = data;

	ret = of_property_read_u32(np, "ti,davinci-rmii-en", &data);
	if (!ret)
		pdata->rmii_en = data;

	ret = of_property_read_u32(np, "ti,davinci-no-bd-ram", &data);
	if (!ret)
		pdata->no_bd_ram = data;

	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);
	if (!priv->phy_node)
		pdata->phy_id = "";

	pdev->dev.platform_data = pdata;
nodata:
	return  pdata;
}
#else
static struct emac_platform_data
	*davinci_emac_of_get_pdata(struct platform_device *pdev,
	struct emac_priv *priv)
{
	return  pdev->dev.platform_data;
}
#endif
/**
 * davinci_emac_probe - EMAC device probe
 * @pdev: The DaVinci EMAC device that we are removing
 *
 * Called when probing for emac devicesr. We get details of instances and
 * resource information from platform init and register a network device
 * and allocate resources necessary for driver to perform
 */
static int davinci_emac_probe(struct platform_device *pdev)
{
	int rc = 0;
	struct resource *res;
	struct net_device *ndev;
	struct emac_priv *priv;
	unsigned long size, hw_ram_addr;
	struct emac_platform_data *pdata;
	struct device *emac_dev;
	struct cpdma_params dma_params;
	struct clk *emac_clk;
	unsigned long emac_bus_frequency;


	/* obtain emac clock from kernel */
	emac_clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(emac_clk)) {
		dev_err(&pdev->dev, "failed to get EMAC clock\n");
		return -EBUSY;
	}
	emac_bus_frequency = clk_get_rate(emac_clk);
	clk_put(emac_clk);

	/* TODO: Probe PHY here if possible */

	ndev = alloc_etherdev(sizeof(struct emac_priv));
	if (!ndev) {
		rc = -ENOMEM;
		goto no_ndev;
	}

	platform_set_drvdata(pdev, ndev);
	priv = netdev_priv(ndev);
	priv->pdev = pdev;
	priv->ndev = ndev;
	priv->msg_enable = netif_msg_init(debug_level, DAVINCI_EMAC_DEBUG);

	spin_lock_init(&priv->lock);

	pdata = davinci_emac_of_get_pdata(pdev, priv);
	if (!pdata) {
		dev_err(&pdev->dev, "no platform data\n");
		rc = -ENODEV;
		goto probe_quit;
	}

	/* MAC addr and PHY mask , RMII enable info from platform_data */
	memcpy(priv->mac_addr, pdata->mac_addr, 6);
	priv->phy_id = pdata->phy_id;
	priv->rmii_en = pdata->rmii_en;
	priv->version = pdata->version;
	priv->int_enable = pdata->interrupt_enable;
	priv->int_disable = pdata->interrupt_disable;

	priv->coal_intvl = 0;
	priv->bus_freq_mhz = (u32)(emac_bus_frequency / 1000000);

	emac_dev = &ndev->dev;
	/* Get EMAC platform data */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev,"error getting res\n");
		rc = -ENOENT;
		goto probe_quit;
	}

	priv->emac_base_phys = res->start + pdata->ctrl_reg_offset;
	size = resource_size(res);
	if (!request_mem_region(res->start, size, ndev->name)) {
		dev_err(&pdev->dev, "failed request_mem_region() for regs\n");
		rc = -ENXIO;
		goto probe_quit;
	}

	priv->remap_addr = ioremap(res->start, size);
	if (!priv->remap_addr) {
		dev_err(&pdev->dev, "unable to map IO\n");
		rc = -ENOMEM;
		release_mem_region(res->start, size);
		goto probe_quit;
	}
	priv->emac_base = priv->remap_addr + pdata->ctrl_reg_offset;
	ndev->base_addr = (unsigned long)priv->remap_addr;

	priv->ctrl_base = priv->remap_addr + pdata->ctrl_mod_reg_offset;

	hw_ram_addr = pdata->hw_ram_addr;
	if (!hw_ram_addr)
		hw_ram_addr = (u32 __force)res->start + pdata->ctrl_ram_offset;

	memset(&dma_params, 0, sizeof(dma_params));
	dma_params.dev			= emac_dev;
	dma_params.dmaregs		= priv->emac_base;
	dma_params.rxthresh		= priv->emac_base + 0x120;
	dma_params.rxfree		= priv->emac_base + 0x140;
	dma_params.txhdp		= priv->emac_base + 0x600;
	dma_params.rxhdp		= priv->emac_base + 0x620;
	dma_params.txcp			= priv->emac_base + 0x640;
	dma_params.rxcp			= priv->emac_base + 0x660;
	dma_params.num_chan		= EMAC_MAX_TXRX_CHANNELS;
	dma_params.min_packet_size	= EMAC_DEF_MIN_ETHPKTSIZE;
	dma_params.desc_hw_addr		= hw_ram_addr;
	dma_params.desc_mem_size	= pdata->ctrl_ram_size;
	dma_params.desc_align		= 16;

	dma_params.desc_mem_phys = pdata->no_bd_ram ? 0 :
			(u32 __force)res->start + pdata->ctrl_ram_offset;

	priv->dma = cpdma_ctlr_create(&dma_params);
	if (!priv->dma) {
		dev_err(&pdev->dev, "error initializing DMA\n");
		rc = -ENOMEM;
		goto no_dma;
	}

	priv->txchan = cpdma_chan_create(priv->dma, tx_chan_num(EMAC_DEF_TX_CH),
				       emac_tx_handler);
	priv->rxchan = cpdma_chan_create(priv->dma, rx_chan_num(EMAC_DEF_RX_CH),
				       emac_rx_handler);
	if (WARN_ON(!priv->txchan || !priv->rxchan)) {
		rc = -ENOMEM;
		goto no_irq_res;
	}

	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	if (!res) {
		dev_err(&pdev->dev, "error getting irq res\n");
		rc = -ENOENT;
		goto no_irq_res;
	}
	ndev->irq = res->start;

	if (!is_valid_ether_addr(priv->mac_addr)) {
		/* Use random MAC if none passed */
		eth_hw_addr_random(ndev);
		memcpy(priv->mac_addr, ndev->dev_addr, ndev->addr_len);
		dev_warn(&pdev->dev, "using random MAC addr: %pM\n",
							priv->mac_addr);
	}

	ndev->netdev_ops = &emac_netdev_ops;
	SET_ETHTOOL_OPS(ndev, &ethtool_ops);
	netif_napi_add(ndev, &priv->napi, emac_poll, EMAC_POLL_WEIGHT);

	/* register the network device */
	SET_NETDEV_DEV(ndev, &pdev->dev);
	rc = register_netdev(ndev);
	if (rc) {
		dev_err(&pdev->dev, "error in register_netdev\n");
		rc = -ENODEV;
		goto no_irq_res;
	}


	if (netif_msg_probe(priv)) {
		dev_notice(emac_dev, "DaVinci EMAC Probe found device "\
			   "(regs: %p, irq: %d)\n",
			   (void *)priv->emac_base_phys, ndev->irq);
	}

	pm_runtime_enable(&pdev->dev);
	pm_runtime_resume(&pdev->dev);

	return 0;

no_irq_res:
	if (priv->txchan)
		cpdma_chan_destroy(priv->txchan);
	if (priv->rxchan)
		cpdma_chan_destroy(priv->rxchan);
	cpdma_ctlr_destroy(priv->dma);
no_dma:
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(res->start, resource_size(res));
	iounmap(priv->remap_addr);

probe_quit:
	free_netdev(ndev);
no_ndev:
	return rc;
}

/**
 * davinci_emac_remove - EMAC device remove
 * @pdev: The DaVinci EMAC device that we are removing
 *
 * Called when removing the device driver. We disable clock usage and release
 * the resources taken up by the driver and unregister network device
 */
static int davinci_emac_remove(struct platform_device *pdev)
{
	struct resource *res;
	struct net_device *ndev = platform_get_drvdata(pdev);
	struct emac_priv *priv = netdev_priv(ndev);

	dev_notice(&ndev->dev, "DaVinci EMAC: davinci_emac_remove()\n");

	platform_set_drvdata(pdev, NULL);
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (priv->txchan)
		cpdma_chan_destroy(priv->txchan);
	if (priv->rxchan)
		cpdma_chan_destroy(priv->rxchan);
	cpdma_ctlr_destroy(priv->dma);

	release_mem_region(res->start, resource_size(res));

	unregister_netdev(ndev);
	iounmap(priv->remap_addr);
	free_netdev(ndev);

	return 0;
}

static int davinci_emac_suspend(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct net_device *ndev = platform_get_drvdata(pdev);

	if (netif_running(ndev))
		emac_dev_stop(ndev);

	return 0;
}

static int davinci_emac_resume(struct device *dev)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct net_device *ndev = platform_get_drvdata(pdev);

	if (netif_running(ndev))
		emac_dev_open(ndev);

	return 0;
}

static const struct dev_pm_ops davinci_emac_pm_ops = {
	.suspend	= davinci_emac_suspend,
	.resume		= davinci_emac_resume,
};

static const struct of_device_id davinci_emac_of_match[] = {
	{.compatible = "ti,davinci-dm6467-emac", },
	{},
};
MODULE_DEVICE_TABLE(of, davinci_emac_of_match);

/* davinci_emac_driver: EMAC platform driver structure */
static struct platform_driver davinci_emac_driver = {
	.driver = {
		.name	 = "davinci_emac",
		.owner	 = THIS_MODULE,
		.pm	 = &davinci_emac_pm_ops,
		.of_match_table = of_match_ptr(davinci_emac_of_match),
	},
	.probe = davinci_emac_probe,
	.remove = davinci_emac_remove,
};

/**
 * davinci_emac_init - EMAC driver module init
 *
 * Called when initializing the driver. We register the driver with
 * the platform.
 */
static int __init davinci_emac_init(void)
{
	return platform_driver_register(&davinci_emac_driver);
}
late_initcall(davinci_emac_init);

/**
 * davinci_emac_exit - EMAC driver module exit
 *
 * Called when exiting the driver completely. We unregister the driver with
 * the platform and exit
 */
static void __exit davinci_emac_exit(void)
{
	platform_driver_unregister(&davinci_emac_driver);
}
module_exit(davinci_emac_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("DaVinci EMAC Maintainer: Anant Gole <anantgole@ti.com>");
MODULE_AUTHOR("DaVinci EMAC Maintainer: Chaithrika U S <chaithrika@ti.com>");
MODULE_DESCRIPTION("DaVinci EMAC Ethernet driver");