// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2010-2011 Calxeda, Inc.
 */
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/kernel.h>
#include <linux/circ_buf.h>
#include <linux/interrupt.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/if.h>
#include <linux/crc32.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

/* XGMAC Register definitions */
#define XGMAC_CONTROL           0x00000000      /* MAC Configuration */
#define XGMAC_FRAME_FILTER      0x00000004      /* MAC Frame Filter */
#define XGMAC_FLOW_CTRL         0x00000018      /* MAC Flow Control */
#define XGMAC_VLAN_TAG          0x0000001C      /* VLAN Tags */
#define XGMAC_VERSION           0x00000020      /* Version */
#define XGMAC_VLAN_INCL         0x00000024      /* VLAN tag for tx frames */
#define XGMAC_LPI_CTRL          0x00000028      /* LPI Control and Status */
#define XGMAC_LPI_TIMER         0x0000002C      /* LPI Timers Control */
#define XGMAC_TX_PACE           0x00000030      /* Transmit Pace and Stretch */
#define XGMAC_VLAN_HASH         0x00000034      /* VLAN Hash Table */
#define XGMAC_DEBUG             0x00000038      /* Debug */
#define XGMAC_INT_STAT          0x0000003C      /* Interrupt and Control */
#define XGMAC_ADDR_HIGH(reg)    (0x00000040 + ((reg) * 8))
#define XGMAC_ADDR_LOW(reg)     (0x00000044 + ((reg) * 8))
#define XGMAC_HASH(n)           (0x00000300 + (n) * 4) /* HASH table regs */
#define XGMAC_NUM_HASH          16
#define XGMAC_OMR               0x00000400
#define XGMAC_REMOTE_WAKE       0x00000700      /* Remote Wake-Up Frm Filter */
#define XGMAC_PMT               0x00000704      /* PMT Control and Status */
#define XGMAC_MMC_CTRL          0x00000800      /* XGMAC MMC Control */
#define XGMAC_MMC_INTR_RX       0x00000804      /* Receive Interrupt */
#define XGMAC_MMC_INTR_TX       0x00000808      /* Transmit Interrupt */
#define XGMAC_MMC_INTR_MASK_RX  0x0000080c      /* Receive Interrupt Mask */
#define XGMAC_MMC_INTR_MASK_TX  0x00000810      /* Transmit Interrupt Mask */

/* Hardware TX Statistics Counters */
#define XGMAC_MMC_TXOCTET_GB_LO 0x00000814
#define XGMAC_MMC_TXOCTET_GB_HI 0x00000818
#define XGMAC_MMC_TXFRAME_GB_LO 0x0000081C
#define XGMAC_MMC_TXFRAME_GB_HI 0x00000820
#define XGMAC_MMC_TXBCFRAME_G   0x00000824
#define XGMAC_MMC_TXMCFRAME_G   0x0000082C
#define XGMAC_MMC_TXUCFRAME_GB  0x00000864
#define XGMAC_MMC_TXMCFRAME_GB  0x0000086C
#define XGMAC_MMC_TXBCFRAME_GB  0x00000874
#define XGMAC_MMC_TXUNDERFLOW   0x0000087C
#define XGMAC_MMC_TXOCTET_G_LO  0x00000884
#define XGMAC_MMC_TXOCTET_G_HI  0x00000888
#define XGMAC_MMC_TXFRAME_G_LO  0x0000088C
#define XGMAC_MMC_TXFRAME_G_HI  0x00000890
#define XGMAC_MMC_TXPAUSEFRAME  0x00000894
#define XGMAC_MMC_TXVLANFRAME   0x0000089C

/* Hardware RX Statistics Counters */
#define XGMAC_MMC_RXFRAME_GB_LO 0x00000900
#define XGMAC_MMC_RXFRAME_GB_HI 0x00000904
#define XGMAC_MMC_RXOCTET_GB_LO 0x00000908
#define XGMAC_MMC_RXOCTET_GB_HI 0x0000090C
#define XGMAC_MMC_RXOCTET_G_LO  0x00000910
#define XGMAC_MMC_RXOCTET_G_HI  0x00000914
#define XGMAC_MMC_RXBCFRAME_G   0x00000918
#define XGMAC_MMC_RXMCFRAME_G   0x00000920
#define XGMAC_MMC_RXCRCERR      0x00000928
#define XGMAC_MMC_RXRUNT        0x00000930
#define XGMAC_MMC_RXJABBER      0x00000934
#define XGMAC_MMC_RXUCFRAME_G   0x00000970
#define XGMAC_MMC_RXLENGTHERR   0x00000978
#define XGMAC_MMC_RXPAUSEFRAME  0x00000988
#define XGMAC_MMC_RXOVERFLOW    0x00000990
#define XGMAC_MMC_RXVLANFRAME   0x00000998
#define XGMAC_MMC_RXWATCHDOG    0x000009a0

/* DMA Control and Status Registers */
#define XGMAC_DMA_BUS_MODE      0x00000f00      /* Bus Mode */
#define XGMAC_DMA_TX_POLL       0x00000f04      /* Transmit Poll Demand */
#define XGMAC_DMA_RX_POLL       0x00000f08      /* Received Poll Demand */
#define XGMAC_DMA_RX_BASE_ADDR  0x00000f0c      /* Receive List Base */
#define XGMAC_DMA_TX_BASE_ADDR  0x00000f10      /* Transmit List Base */
#define XGMAC_DMA_STATUS        0x00000f14      /* Status Register */
#define XGMAC_DMA_CONTROL       0x00000f18      /* Ctrl (Operational Mode) */
#define XGMAC_DMA_INTR_ENA      0x00000f1c      /* Interrupt Enable */
#define XGMAC_DMA_MISS_FRAME_CTR 0x00000f20     /* Missed Frame Counter */
#define XGMAC_DMA_RI_WDOG_TIMER 0x00000f24      /* RX Intr Watchdog Timer */
#define XGMAC_DMA_AXI_BUS       0x00000f28      /* AXI Bus Mode */
#define XGMAC_DMA_AXI_STATUS    0x00000f2C      /* AXI Status */
#define XGMAC_DMA_HW_FEATURE    0x00000f58      /* Enabled Hardware Features */

#define XGMAC_ADDR_AE           0x80000000

/* PMT Control and Status */
#define XGMAC_PMT_POINTER_RESET 0x80000000
#define XGMAC_PMT_GLBL_UNICAST  0x00000200
#define XGMAC_PMT_WAKEUP_RX_FRM 0x00000040
#define XGMAC_PMT_MAGIC_PKT     0x00000020
#define XGMAC_PMT_WAKEUP_FRM_EN 0x00000004
#define XGMAC_PMT_MAGIC_PKT_EN  0x00000002
#define XGMAC_PMT_POWERDOWN     0x00000001

#define XGMAC_CONTROL_SPD       0x40000000      /* Speed control */
#define XGMAC_CONTROL_SPD_MASK  0x60000000
#define XGMAC_CONTROL_SPD_1G    0x60000000
#define XGMAC_CONTROL_SPD_2_5G  0x40000000
#define XGMAC_CONTROL_SPD_10G   0x00000000
#define XGMAC_CONTROL_SARC      0x10000000      /* Source Addr Insert/Replace */
#define XGMAC_CONTROL_SARK_MASK 0x18000000
#define XGMAC_CONTROL_CAR       0x04000000      /* CRC Addition/Replacement */
#define XGMAC_CONTROL_CAR_MASK  0x06000000
#define XGMAC_CONTROL_DP        0x01000000      /* Disable Padding */
#define XGMAC_CONTROL_WD        0x00800000      /* Disable Watchdog on rx */
#define XGMAC_CONTROL_JD        0x00400000      /* Jabber disable */
#define XGMAC_CONTROL_JE        0x00100000      /* Jumbo frame */
#define XGMAC_CONTROL_LM        0x00001000      /* Loop-back mode */
#define XGMAC_CONTROL_IPC       0x00000400      /* Checksum Offload */
#define XGMAC_CONTROL_ACS       0x00000080      /* Automatic Pad/FCS Strip */
#define XGMAC_CONTROL_DDIC      0x00000010      /* Disable Deficit Idle Count */
#define XGMAC_CONTROL_TE        0x00000008      /* Transmitter Enable */
#define XGMAC_CONTROL_RE        0x00000004      /* Receiver Enable */

/* XGMAC Frame Filter defines */
#define XGMAC_FRAME_FILTER_PR   0x00000001      /* Promiscuous Mode */
#define XGMAC_FRAME_FILTER_HUC  0x00000002      /* Hash Unicast */
#define XGMAC_FRAME_FILTER_HMC  0x00000004      /* Hash Multicast */
#define XGMAC_FRAME_FILTER_DAIF 0x00000008      /* DA Inverse Filtering */
#define XGMAC_FRAME_FILTER_PM   0x00000010      /* Pass all multicast */
#define XGMAC_FRAME_FILTER_DBF  0x00000020      /* Disable Broadcast frames */
#define XGMAC_FRAME_FILTER_SAIF 0x00000100      /* Inverse Filtering */
#define XGMAC_FRAME_FILTER_SAF  0x00000200      /* Source Address Filter */
#define XGMAC_FRAME_FILTER_HPF  0x00000400      /* Hash or perfect Filter */
#define XGMAC_FRAME_FILTER_VHF  0x00000800      /* VLAN Hash Filter */
#define XGMAC_FRAME_FILTER_VPF  0x00001000      /* VLAN Perfect Filter */
#define XGMAC_FRAME_FILTER_RA   0x80000000      /* Receive all mode */

/* XGMAC FLOW CTRL defines */
#define XGMAC_FLOW_CTRL_PT_MASK 0xffff0000      /* Pause Time Mask */
#define XGMAC_FLOW_CTRL_PT_SHIFT        16
#define XGMAC_FLOW_CTRL_DZQP    0x00000080      /* Disable Zero-Quanta Phase */
#define XGMAC_FLOW_CTRL_PLT     0x00000020      /* Pause Low Threshold */
#define XGMAC_FLOW_CTRL_PLT_MASK 0x00000030     /* PLT MASK */
#define XGMAC_FLOW_CTRL_UP      0x00000008      /* Unicast Pause Frame Detect */
#define XGMAC_FLOW_CTRL_RFE     0x00000004      /* Rx Flow Control Enable */
#define XGMAC_FLOW_CTRL_TFE     0x00000002      /* Tx Flow Control Enable */
#define XGMAC_FLOW_CTRL_FCB_BPA 0x00000001      /* Flow Control Busy ... */

/* XGMAC_INT_STAT reg */
#define XGMAC_INT_STAT_PMTIM    0x00800000      /* PMT Interrupt Mask */
#define XGMAC_INT_STAT_PMT      0x0080          /* PMT Interrupt Status */
#define XGMAC_INT_STAT_LPI      0x0040          /* LPI Interrupt Status */

/* DMA Bus Mode register defines */
#define DMA_BUS_MODE_SFT_RESET  0x00000001      /* Software Reset */
#define DMA_BUS_MODE_DSL_MASK   0x0000007c      /* Descriptor Skip Length */
#define DMA_BUS_MODE_DSL_SHIFT  2               /* (in DWORDS) */
#define DMA_BUS_MODE_ATDS       0x00000080      /* Alternate Descriptor Size */

/* Programmable burst length */
#define DMA_BUS_MODE_PBL_MASK   0x00003f00      /* Programmable Burst Len */
#define DMA_BUS_MODE_PBL_SHIFT  8
#define DMA_BUS_MODE_FB         0x00010000      /* Fixed burst */
#define DMA_BUS_MODE_RPBL_MASK  0x003e0000      /* Rx-Programmable Burst Len */
#define DMA_BUS_MODE_RPBL_SHIFT 17
#define DMA_BUS_MODE_USP        0x00800000
#define DMA_BUS_MODE_8PBL       0x01000000
#define DMA_BUS_MODE_AAL        0x02000000

/* DMA Bus Mode register defines */
#define DMA_BUS_PR_RATIO_MASK   0x0000c000      /* Rx/Tx priority ratio */
#define DMA_BUS_PR_RATIO_SHIFT  14
#define DMA_BUS_FB              0x00010000      /* Fixed Burst */

/* DMA Control register defines */
#define DMA_CONTROL_ST          0x00002000      /* Start/Stop Transmission */
#define DMA_CONTROL_SR          0x00000002      /* Start/Stop Receive */
#define DMA_CONTROL_DFF         0x01000000      /* Disable flush of rx frames */
#define DMA_CONTROL_OSF         0x00000004      /* Operate on 2nd tx frame */

/* DMA Normal interrupt */
#define DMA_INTR_ENA_NIE        0x00010000      /* Normal Summary */
#define DMA_INTR_ENA_AIE        0x00008000      /* Abnormal Summary */
#define DMA_INTR_ENA_ERE        0x00004000      /* Early Receive */
#define DMA_INTR_ENA_FBE        0x00002000      /* Fatal Bus Error */
#define DMA_INTR_ENA_ETE        0x00000400      /* Early Transmit */
#define DMA_INTR_ENA_RWE        0x00000200      /* Receive Watchdog */
#define DMA_INTR_ENA_RSE        0x00000100      /* Receive Stopped */
#define DMA_INTR_ENA_RUE        0x00000080      /* Receive Buffer Unavailable */
#define DMA_INTR_ENA_RIE        0x00000040      /* Receive Interrupt */
#define DMA_INTR_ENA_UNE        0x00000020      /* Tx Underflow */
#define DMA_INTR_ENA_OVE        0x00000010      /* Receive Overflow */
#define DMA_INTR_ENA_TJE        0x00000008      /* Transmit Jabber */
#define DMA_INTR_ENA_TUE        0x00000004      /* Transmit Buffer Unavail */
#define DMA_INTR_ENA_TSE        0x00000002      /* Transmit Stopped */
#define DMA_INTR_ENA_TIE        0x00000001      /* Transmit Interrupt */

#define DMA_INTR_NORMAL         (DMA_INTR_ENA_NIE | DMA_INTR_ENA_RIE | \
                                 DMA_INTR_ENA_TUE | DMA_INTR_ENA_TIE)

#define DMA_INTR_ABNORMAL       (DMA_INTR_ENA_AIE | DMA_INTR_ENA_FBE | \
                                 DMA_INTR_ENA_RWE | DMA_INTR_ENA_RSE | \
                                 DMA_INTR_ENA_RUE | DMA_INTR_ENA_UNE | \
                                 DMA_INTR_ENA_OVE | DMA_INTR_ENA_TJE | \
                                 DMA_INTR_ENA_TSE)

/* DMA default interrupt mask */
#define DMA_INTR_DEFAULT_MASK   (DMA_INTR_NORMAL | DMA_INTR_ABNORMAL)

/* DMA Status register defines */
#define DMA_STATUS_GMI          0x08000000      /* MMC interrupt */
#define DMA_STATUS_GLI          0x04000000      /* GMAC Line interface int */
#define DMA_STATUS_EB_MASK      0x00380000      /* Error Bits Mask */
#define DMA_STATUS_EB_TX_ABORT  0x00080000      /* Error Bits - TX Abort */
#define DMA_STATUS_EB_RX_ABORT  0x00100000      /* Error Bits - RX Abort */
#define DMA_STATUS_TS_MASK      0x00700000      /* Transmit Process State */
#define DMA_STATUS_TS_SHIFT     20
#define DMA_STATUS_RS_MASK      0x000e0000      /* Receive Process State */
#define DMA_STATUS_RS_SHIFT     17
#define DMA_STATUS_NIS          0x00010000      /* Normal Interrupt Summary */
#define DMA_STATUS_AIS          0x00008000      /* Abnormal Interrupt Summary */
#define DMA_STATUS_ERI          0x00004000      /* Early Receive Interrupt */
#define DMA_STATUS_FBI          0x00002000      /* Fatal Bus Error Interrupt */
#define DMA_STATUS_ETI          0x00000400      /* Early Transmit Interrupt */
#define DMA_STATUS_RWT          0x00000200      /* Receive Watchdog Timeout */
#define DMA_STATUS_RPS          0x00000100      /* Receive Process Stopped */
#define DMA_STATUS_RU           0x00000080      /* Receive Buffer Unavailable */
#define DMA_STATUS_RI           0x00000040      /* Receive Interrupt */
#define DMA_STATUS_UNF          0x00000020      /* Transmit Underflow */
#define DMA_STATUS_OVF          0x00000010      /* Receive Overflow */
#define DMA_STATUS_TJT          0x00000008      /* Transmit Jabber Timeout */
#define DMA_STATUS_TU           0x00000004      /* Transmit Buffer Unavail */
#define DMA_STATUS_TPS          0x00000002      /* Transmit Process Stopped */
#define DMA_STATUS_TI           0x00000001      /* Transmit Interrupt */

/* Common MAC defines */
#define MAC_ENABLE_TX           0x00000008      /* Transmitter Enable */
#define MAC_ENABLE_RX           0x00000004      /* Receiver Enable */

/* XGMAC Operation Mode Register */
#define XGMAC_OMR_TSF           0x00200000      /* TX FIFO Store and Forward */
#define XGMAC_OMR_FTF           0x00100000      /* Flush Transmit FIFO */
#define XGMAC_OMR_TTC           0x00020000      /* Transmit Threshold Ctrl */
#define XGMAC_OMR_TTC_MASK      0x00030000
#define XGMAC_OMR_RFD           0x00006000      /* FC Deactivation Threshold */
#define XGMAC_OMR_RFD_MASK      0x00007000      /* FC Deact Threshold MASK */
#define XGMAC_OMR_RFA           0x00000600      /* FC Activation Threshold */
#define XGMAC_OMR_RFA_MASK      0x00000E00      /* FC Act Threshold MASK */
#define XGMAC_OMR_EFC           0x00000100      /* Enable Hardware FC */
#define XGMAC_OMR_FEF           0x00000080      /* Forward Error Frames */
#define XGMAC_OMR_DT            0x00000040      /* Drop TCP/IP csum Errors */
#define XGMAC_OMR_RSF           0x00000020      /* RX FIFO Store and Forward */
#define XGMAC_OMR_RTC_256       0x00000018      /* RX Threshold Ctrl */
#define XGMAC_OMR_RTC_MASK      0x00000018      /* RX Threshold Ctrl MASK */

/* XGMAC HW Features Register */
#define DMA_HW_FEAT_TXCOESEL    0x00010000      /* TX Checksum offload */

#define XGMAC_MMC_CTRL_CNT_FRZ  0x00000008

/* XGMAC Descriptor Defines */
#define MAX_DESC_BUF_SZ         (0x2000 - 8)

#define RXDESC_EXT_STATUS       0x00000001
#define RXDESC_CRC_ERR          0x00000002
#define RXDESC_RX_ERR           0x00000008
#define RXDESC_RX_WDOG          0x00000010
#define RXDESC_FRAME_TYPE       0x00000020
#define RXDESC_GIANT_FRAME      0x00000080
#define RXDESC_LAST_SEG         0x00000100
#define RXDESC_FIRST_SEG        0x00000200
#define RXDESC_VLAN_FRAME       0x00000400
#define RXDESC_OVERFLOW_ERR     0x00000800
#define RXDESC_LENGTH_ERR       0x00001000
#define RXDESC_SA_FILTER_FAIL   0x00002000
#define RXDESC_DESCRIPTOR_ERR   0x00004000
#define RXDESC_ERROR_SUMMARY    0x00008000
#define RXDESC_FRAME_LEN_OFFSET 16
#define RXDESC_FRAME_LEN_MASK   0x3fff0000
#define RXDESC_DA_FILTER_FAIL   0x40000000

#define RXDESC1_END_RING        0x00008000

#define RXDESC_IP_PAYLOAD_MASK  0x00000003
#define RXDESC_IP_PAYLOAD_UDP   0x00000001
#define RXDESC_IP_PAYLOAD_TCP   0x00000002
#define RXDESC_IP_PAYLOAD_ICMP  0x00000003
#define RXDESC_IP_HEADER_ERR    0x00000008
#define RXDESC_IP_PAYLOAD_ERR   0x00000010
#define RXDESC_IPV4_PACKET      0x00000040
#define RXDESC_IPV6_PACKET      0x00000080
#define TXDESC_UNDERFLOW_ERR    0x00000001
#define TXDESC_JABBER_TIMEOUT   0x00000002
#define TXDESC_LOCAL_FAULT      0x00000004
#define TXDESC_REMOTE_FAULT     0x00000008
#define TXDESC_VLAN_FRAME       0x00000010
#define TXDESC_FRAME_FLUSHED    0x00000020
#define TXDESC_IP_HEADER_ERR    0x00000040
#define TXDESC_PAYLOAD_CSUM_ERR 0x00000080
#define TXDESC_ERROR_SUMMARY    0x00008000
#define TXDESC_SA_CTRL_INSERT   0x00040000
#define TXDESC_SA_CTRL_REPLACE  0x00080000
#define TXDESC_2ND_ADDR_CHAINED 0x00100000
#define TXDESC_END_RING         0x00200000
#define TXDESC_CSUM_IP          0x00400000
#define TXDESC_CSUM_IP_PAYLD    0x00800000
#define TXDESC_CSUM_ALL         0x00C00000
#define TXDESC_CRC_EN_REPLACE   0x01000000
#define TXDESC_CRC_EN_APPEND    0x02000000
#define TXDESC_DISABLE_PAD      0x04000000
#define TXDESC_FIRST_SEG        0x10000000
#define TXDESC_LAST_SEG         0x20000000
#define TXDESC_INTERRUPT        0x40000000

#define DESC_OWN                0x80000000
#define DESC_BUFFER1_SZ_MASK    0x00001fff
#define DESC_BUFFER2_SZ_MASK    0x1fff0000
#define DESC_BUFFER2_SZ_OFFSET  16

struct xgmac_dma_desc {
        __le32 flags;
        __le32 buf_size;
        __le32 buf1_addr;               /* Buffer 1 Address Pointer */
        __le32 buf2_addr;               /* Buffer 2 Address Pointer */
        __le32 ext_status;
        __le32 res[3];
};

struct xgmac_extra_stats {
        /* Transmit errors */
        unsigned long tx_jabber;
        unsigned long tx_frame_flushed;
        unsigned long tx_payload_error;
        unsigned long tx_ip_header_error;
        unsigned long tx_local_fault;
        unsigned long tx_remote_fault;
        /* Receive errors */
        unsigned long rx_watchdog;
        unsigned long rx_da_filter_fail;
        unsigned long rx_payload_error;
        unsigned long rx_ip_header_error;
        /* Tx/Rx IRQ errors */
        unsigned long tx_process_stopped;
        unsigned long rx_buf_unav;
        unsigned long rx_process_stopped;
        unsigned long tx_early;
        unsigned long fatal_bus_error;
};

struct xgmac_priv {
        struct xgmac_dma_desc *dma_rx;
        struct sk_buff **rx_skbuff;
        unsigned int rx_tail;
        unsigned int rx_head;

        struct xgmac_dma_desc *dma_tx;
        struct sk_buff **tx_skbuff;
        unsigned int tx_head;
        unsigned int tx_tail;
        int tx_irq_cnt;

        void __iomem *base;
        unsigned int dma_buf_sz;
        dma_addr_t dma_rx_phy;
        dma_addr_t dma_tx_phy;

        struct net_device *dev;
        struct device *device;
        struct napi_struct napi;

        int max_macs;
        struct xgmac_extra_stats xstats;

        spinlock_t stats_lock;
        int pmt_irq;
        char rx_pause;
        char tx_pause;
        int wolopts;
        struct work_struct tx_timeout_work;
};

/* XGMAC Configuration Settings */
#define XGMAC_MAX_MTU           9000
#define PAUSE_TIME              0x400

#define DMA_RX_RING_SZ          256
#define DMA_TX_RING_SZ          128
/* minimum number of free TX descriptors required to wake up TX process */
#define TX_THRESH               (DMA_TX_RING_SZ/4)

/* DMA descriptor ring helpers */
#define dma_ring_incr(n, s)     (((n) + 1) & ((s) - 1))
#define dma_ring_space(h, t, s) CIRC_SPACE(h, t, s)
#define dma_ring_cnt(h, t, s)   CIRC_CNT(h, t, s)

#define tx_dma_ring_space(p) \
        dma_ring_space((p)->tx_head, (p)->tx_tail, DMA_TX_RING_SZ)

/* XGMAC Descriptor Access Helpers */
static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz)
{
        if (buf_sz > MAX_DESC_BUF_SZ)
                p->buf_size = cpu_to_le32(MAX_DESC_BUF_SZ |
                        (buf_sz - MAX_DESC_BUF_SZ) << DESC_BUFFER2_SZ_OFFSET);
        else
                p->buf_size = cpu_to_le32(buf_sz);
}

static inline int desc_get_buf_len(struct xgmac_dma_desc *p)
{
        u32 len = le32_to_cpu(p->buf_size);
        return (len & DESC_BUFFER1_SZ_MASK) +
                ((len & DESC_BUFFER2_SZ_MASK) >> DESC_BUFFER2_SZ_OFFSET);
}

static inline void desc_init_rx_desc(struct xgmac_dma_desc *p, int ring_size,
                                     int buf_sz)
{
        struct xgmac_dma_desc *end = p + ring_size - 1;

        memset(p, 0, sizeof(*p) * ring_size);

        for (; p <= end; p++)
                desc_set_buf_len(p, buf_sz);

        end->buf_size |= cpu_to_le32(RXDESC1_END_RING);
}

static inline void desc_init_tx_desc(struct xgmac_dma_desc *p, u32 ring_size)
{
        memset(p, 0, sizeof(*p) * ring_size);
        p[ring_size - 1].flags = cpu_to_le32(TXDESC_END_RING);
}

static inline int desc_get_owner(struct xgmac_dma_desc *p)
{
        return le32_to_cpu(p->flags) & DESC_OWN;
}

static inline void desc_set_rx_owner(struct xgmac_dma_desc *p)
{
        /* Clear all fields and set the owner */
        p->flags = cpu_to_le32(DESC_OWN);
}

static inline void desc_set_tx_owner(struct xgmac_dma_desc *p, u32 flags)
{
        u32 tmpflags = le32_to_cpu(p->flags);
        tmpflags &= TXDESC_END_RING;
        tmpflags |= flags | DESC_OWN;
        p->flags = cpu_to_le32(tmpflags);
}

static inline void desc_clear_tx_owner(struct xgmac_dma_desc *p)
{
        u32 tmpflags = le32_to_cpu(p->flags);
        tmpflags &= TXDESC_END_RING;
        p->flags = cpu_to_le32(tmpflags);
}

static inline int desc_get_tx_ls(struct xgmac_dma_desc *p)
{
        return le32_to_cpu(p->flags) & TXDESC_LAST_SEG;
}

static inline int desc_get_tx_fs(struct xgmac_dma_desc *p)
{
        return le32_to_cpu(p->flags) & TXDESC_FIRST_SEG;
}

static inline u32 desc_get_buf_addr(struct xgmac_dma_desc *p)
{
        return le32_to_cpu(p->buf1_addr);
}

static inline void desc_set_buf_addr(struct xgmac_dma_desc *p,
                                     u32 paddr, int len)
{
        p->buf1_addr = cpu_to_le32(paddr);
        if (len > MAX_DESC_BUF_SZ)
                p->buf2_addr = cpu_to_le32(paddr + MAX_DESC_BUF_SZ);
}

static inline void desc_set_buf_addr_and_size(struct xgmac_dma_desc *p,
                                              u32 paddr, int len)
{
        desc_set_buf_len(p, len);
        desc_set_buf_addr(p, paddr, len);
}

static inline int desc_get_rx_frame_len(struct xgmac_dma_desc *p)
{
        u32 data = le32_to_cpu(p->flags);
        u32 len = (data & RXDESC_FRAME_LEN_MASK) >> RXDESC_FRAME_LEN_OFFSET;
        if (data & RXDESC_FRAME_TYPE)
                len -= ETH_FCS_LEN;

        return len;
}

static void xgmac_dma_flush_tx_fifo(void __iomem *ioaddr)
{
        int timeout = 1000;
        u32 reg = readl(ioaddr + XGMAC_OMR);
        writel(reg | XGMAC_OMR_FTF, ioaddr + XGMAC_OMR);

        while ((timeout-- > 0) && readl(ioaddr + XGMAC_OMR) & XGMAC_OMR_FTF)
                udelay(1);
}

static int desc_get_tx_status(struct xgmac_priv *priv, struct xgmac_dma_desc *p)
{
        struct xgmac_extra_stats *x = &priv->xstats;
        u32 status = le32_to_cpu(p->flags);

        if (!(status & TXDESC_ERROR_SUMMARY))
                return 0;

        netdev_dbg(priv->dev, "tx desc error = 0x%08x\n", status);
        if (status & TXDESC_JABBER_TIMEOUT)
                x->tx_jabber++;
        if (status & TXDESC_FRAME_FLUSHED)
                x->tx_frame_flushed++;
        if (status & TXDESC_UNDERFLOW_ERR)
                xgmac_dma_flush_tx_fifo(priv->base);
        if (status & TXDESC_IP_HEADER_ERR)
                x->tx_ip_header_error++;
        if (status & TXDESC_LOCAL_FAULT)
                x->tx_local_fault++;
        if (status & TXDESC_REMOTE_FAULT)
                x->tx_remote_fault++;
        if (status & TXDESC_PAYLOAD_CSUM_ERR)
                x->tx_payload_error++;

        return -1;
}

static int desc_get_rx_status(struct xgmac_priv *priv, struct xgmac_dma_desc *p)
{
        struct xgmac_extra_stats *x = &priv->xstats;
        int ret = CHECKSUM_UNNECESSARY;
        u32 status = le32_to_cpu(p->flags);
        u32 ext_status = le32_to_cpu(p->ext_status);

        if (status & RXDESC_DA_FILTER_FAIL) {
                netdev_dbg(priv->dev, "XGMAC RX : Dest Address filter fail\n");
                x->rx_da_filter_fail++;
                return -1;
        }

        /* All frames should fit into a single buffer */
        if (!(status & RXDESC_FIRST_SEG) || !(status & RXDESC_LAST_SEG))
                return -1;

        /* Check if packet has checksum already */
        if ((status & RXDESC_FRAME_TYPE) && (status & RXDESC_EXT_STATUS) &&
                !(ext_status & RXDESC_IP_PAYLOAD_MASK))
                ret = CHECKSUM_NONE;

        netdev_dbg(priv->dev, "rx status - frame type=%d, csum = %d, ext stat %08x\n",
                   (status & RXDESC_FRAME_TYPE) ? 1 : 0, ret, ext_status);

        if (!(status & RXDESC_ERROR_SUMMARY))
                return ret;

        /* Handle any errors */
        if (status & (RXDESC_DESCRIPTOR_ERR | RXDESC_OVERFLOW_ERR |
                RXDESC_GIANT_FRAME | RXDESC_LENGTH_ERR | RXDESC_CRC_ERR))
                return -1;

        if (status & RXDESC_EXT_STATUS) {
                if (ext_status & RXDESC_IP_HEADER_ERR)
                        x->rx_ip_header_error++;
                if (ext_status & RXDESC_IP_PAYLOAD_ERR)
                        x->rx_payload_error++;
                netdev_dbg(priv->dev, "IP checksum error - stat %08x\n",
                           ext_status);
                return CHECKSUM_NONE;
        }

        return ret;
}

static inline void xgmac_mac_enable(void __iomem *ioaddr)
{
        u32 value = readl(ioaddr + XGMAC_CONTROL);
        value |= MAC_ENABLE_RX | MAC_ENABLE_TX;
        writel(value, ioaddr + XGMAC_CONTROL);

        value = readl(ioaddr + XGMAC_DMA_CONTROL);
        value |= DMA_CONTROL_ST | DMA_CONTROL_SR;
        writel(value, ioaddr + XGMAC_DMA_CONTROL);
}

static inline void xgmac_mac_disable(void __iomem *ioaddr)
{
        u32 value = readl(ioaddr + XGMAC_DMA_CONTROL);
        value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
        writel(value, ioaddr + XGMAC_DMA_CONTROL);

        value = readl(ioaddr + XGMAC_CONTROL);
        value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX);
        writel(value, ioaddr + XGMAC_CONTROL);
}

static void xgmac_set_mac_addr(void __iomem *ioaddr, unsigned char *addr,
                               int num)
{
        u32 data;

        if (addr) {
                data = (addr[5] << 8) | addr[4] | (num ? XGMAC_ADDR_AE : 0);
                writel(data, ioaddr + XGMAC_ADDR_HIGH(num));
                data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
                writel(data, ioaddr + XGMAC_ADDR_LOW(num));
        } else {
                writel(0, ioaddr + XGMAC_ADDR_HIGH(num));
                writel(0, ioaddr + XGMAC_ADDR_LOW(num));
        }
}

static void xgmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
                               int num)
{
        u32 hi_addr, lo_addr;

        /* Read the MAC address from the hardware */
        hi_addr = readl(ioaddr + XGMAC_ADDR_HIGH(num));
        lo_addr = readl(ioaddr + XGMAC_ADDR_LOW(num));

        /* Extract the MAC address from the high and low words */
        addr[0] = lo_addr & 0xff;
        addr[1] = (lo_addr >> 8) & 0xff;
        addr[2] = (lo_addr >> 16) & 0xff;
        addr[3] = (lo_addr >> 24) & 0xff;
        addr[4] = hi_addr & 0xff;
        addr[5] = (hi_addr >> 8) & 0xff;
}

static int xgmac_set_flow_ctrl(struct xgmac_priv *priv, int rx, int tx)
{
        u32 reg;
        unsigned int flow = 0;

        priv->rx_pause = rx;
        priv->tx_pause = tx;

        if (rx || tx) {
                if (rx)
                        flow |= XGMAC_FLOW_CTRL_RFE;
                if (tx)
                        flow |= XGMAC_FLOW_CTRL_TFE;

                flow |= XGMAC_FLOW_CTRL_PLT | XGMAC_FLOW_CTRL_UP;
                flow |= (PAUSE_TIME << XGMAC_FLOW_CTRL_PT_SHIFT);

                writel(flow, priv->base + XGMAC_FLOW_CTRL);

                reg = readl(priv->base + XGMAC_OMR);
                reg |= XGMAC_OMR_EFC;
                writel(reg, priv->base + XGMAC_OMR);
        } else {
                writel(0, priv->base + XGMAC_FLOW_CTRL);

                reg = readl(priv->base + XGMAC_OMR);
                reg &= ~XGMAC_OMR_EFC;
                writel(reg, priv->base + XGMAC_OMR);
        }

        return 0;
}

static void xgmac_rx_refill(struct xgmac_priv *priv)
{
        struct xgmac_dma_desc *p;
        dma_addr_t paddr;
        int bufsz = priv->dev->mtu + ETH_HLEN + ETH_FCS_LEN;

        while (dma_ring_space(priv->rx_head, priv->rx_tail, DMA_RX_RING_SZ) > 1) {
                int entry = priv->rx_head;
                struct sk_buff *skb;

                p = priv->dma_rx + entry;

                if (priv->rx_skbuff[entry] == NULL) {
                        skb = netdev_alloc_skb_ip_align(priv->dev, bufsz);
                        if (unlikely(skb == NULL))
                                break;

                        paddr = dma_map_single(priv->device, skb->data,
                                               priv->dma_buf_sz - NET_IP_ALIGN,
                                               DMA_FROM_DEVICE);
                        if (dma_mapping_error(priv->device, paddr)) {
                                dev_kfree_skb_any(skb);
                                break;
                        }
                        priv->rx_skbuff[entry] = skb;
                        desc_set_buf_addr(p, paddr, priv->dma_buf_sz);
                }

                netdev_dbg(priv->dev, "rx ring: head %d, tail %d\n",
                        priv->rx_head, priv->rx_tail);

                priv->rx_head = dma_ring_incr(priv->rx_head, DMA_RX_RING_SZ);
                desc_set_rx_owner(p);
        }
}

/**
 * xgmac_dma_desc_rings_init - init the RX/TX descriptor rings
 * @dev: net device structure
 * Description:  this function initializes the DMA RX/TX descriptors
 * and allocates the socket buffers.
 */
static int xgmac_dma_desc_rings_init(struct net_device *dev)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        unsigned int bfsize;

        /* Set the Buffer size according to the MTU;
         * The total buffer size including any IP offset must be a multiple
         * of 8 bytes.
         */
        bfsize = ALIGN(dev->mtu + ETH_HLEN + ETH_FCS_LEN + NET_IP_ALIGN, 8);

        netdev_dbg(priv->dev, "mtu [%d] bfsize [%d]\n", dev->mtu, bfsize);

        priv->rx_skbuff = kcalloc(DMA_RX_RING_SZ, sizeof(struct sk_buff *),
                                  GFP_KERNEL);
        if (!priv->rx_skbuff)
                return -ENOMEM;

        priv->dma_rx = dma_alloc_coherent(priv->device,
                                          DMA_RX_RING_SZ *
                                          sizeof(struct xgmac_dma_desc),
                                          &priv->dma_rx_phy,
                                          GFP_KERNEL);
        if (!priv->dma_rx)
                goto err_dma_rx;

        priv->tx_skbuff = kcalloc(DMA_TX_RING_SZ, sizeof(struct sk_buff *),
                                  GFP_KERNEL);
        if (!priv->tx_skbuff)
                goto err_tx_skb;

        priv->dma_tx = dma_alloc_coherent(priv->device,
                                          DMA_TX_RING_SZ *
                                          sizeof(struct xgmac_dma_desc),
                                          &priv->dma_tx_phy,
                                          GFP_KERNEL);
        if (!priv->dma_tx)
                goto err_dma_tx;

        netdev_dbg(priv->dev, "DMA desc rings: virt addr (Rx %p, "
            "Tx %p)\n\tDMA phy addr (Rx 0x%08x, Tx 0x%08x)\n",
            priv->dma_rx, priv->dma_tx,
            (unsigned int)priv->dma_rx_phy, (unsigned int)priv->dma_tx_phy);

        priv->rx_tail = 0;
        priv->rx_head = 0;
        priv->dma_buf_sz = bfsize;
        desc_init_rx_desc(priv->dma_rx, DMA_RX_RING_SZ, priv->dma_buf_sz);
        xgmac_rx_refill(priv);

        priv->tx_tail = 0;
        priv->tx_head = 0;
        desc_init_tx_desc(priv->dma_tx, DMA_TX_RING_SZ);

        writel(priv->dma_tx_phy, priv->base + XGMAC_DMA_TX_BASE_ADDR);
        writel(priv->dma_rx_phy, priv->base + XGMAC_DMA_RX_BASE_ADDR);

        return 0;

err_dma_tx:
        kfree(priv->tx_skbuff);
err_tx_skb:
        dma_free_coherent(priv->device,
                          DMA_RX_RING_SZ * sizeof(struct xgmac_dma_desc),
                          priv->dma_rx, priv->dma_rx_phy);
err_dma_rx:
        kfree(priv->rx_skbuff);
        return -ENOMEM;
}

static void xgmac_free_rx_skbufs(struct xgmac_priv *priv)
{
        int i;
        struct xgmac_dma_desc *p;

        if (!priv->rx_skbuff)
                return;

        for (i = 0; i < DMA_RX_RING_SZ; i++) {
                struct sk_buff *skb = priv->rx_skbuff[i];
                if (skb == NULL)
                        continue;

                p = priv->dma_rx + i;
                dma_unmap_single(priv->device, desc_get_buf_addr(p),
                                 priv->dma_buf_sz - NET_IP_ALIGN, DMA_FROM_DEVICE);
                dev_kfree_skb_any(skb);
                priv->rx_skbuff[i] = NULL;
        }
}

static void xgmac_free_tx_skbufs(struct xgmac_priv *priv)
{
        int i;
        struct xgmac_dma_desc *p;

        if (!priv->tx_skbuff)
                return;

        for (i = 0; i < DMA_TX_RING_SZ; i++) {
                if (priv->tx_skbuff[i] == NULL)
                        continue;

                p = priv->dma_tx + i;
                if (desc_get_tx_fs(p))
                        dma_unmap_single(priv->device, desc_get_buf_addr(p),
                                         desc_get_buf_len(p), DMA_TO_DEVICE);
                else
                        dma_unmap_page(priv->device, desc_get_buf_addr(p),
                                       desc_get_buf_len(p), DMA_TO_DEVICE);

                if (desc_get_tx_ls(p))
                        dev_kfree_skb_any(priv->tx_skbuff[i]);
                priv->tx_skbuff[i] = NULL;
        }
}

static void xgmac_free_dma_desc_rings(struct xgmac_priv *priv)
{
        /* Release the DMA TX/RX socket buffers */
        xgmac_free_rx_skbufs(priv);
        xgmac_free_tx_skbufs(priv);

        /* Free the consistent memory allocated for descriptor rings */
        if (priv->dma_tx) {
                dma_free_coherent(priv->device,
                                  DMA_TX_RING_SZ * sizeof(struct xgmac_dma_desc),
                                  priv->dma_tx, priv->dma_tx_phy);
                priv->dma_tx = NULL;
        }
        if (priv->dma_rx) {
                dma_free_coherent(priv->device,
                                  DMA_RX_RING_SZ * sizeof(struct xgmac_dma_desc),
                                  priv->dma_rx, priv->dma_rx_phy);
                priv->dma_rx = NULL;
        }
        kfree(priv->rx_skbuff);
        priv->rx_skbuff = NULL;
        kfree(priv->tx_skbuff);
        priv->tx_skbuff = NULL;
}

/**
 * xgmac_tx_complete:
 * @priv: private driver structure
 * Description: it reclaims resources after transmission completes.
 */
static void xgmac_tx_complete(struct xgmac_priv *priv)
{
        while (dma_ring_cnt(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ)) {
                unsigned int entry = priv->tx_tail;
                struct sk_buff *skb = priv->tx_skbuff[entry];
                struct xgmac_dma_desc *p = priv->dma_tx + entry;

                /* Check if the descriptor is owned by the DMA. */
                if (desc_get_owner(p))
                        break;

                netdev_dbg(priv->dev, "tx ring: curr %d, dirty %d\n",
                        priv->tx_head, priv->tx_tail);

                if (desc_get_tx_fs(p))
                        dma_unmap_single(priv->device, desc_get_buf_addr(p),
                                         desc_get_buf_len(p), DMA_TO_DEVICE);
                else
                        dma_unmap_page(priv->device, desc_get_buf_addr(p),
                                       desc_get_buf_len(p), DMA_TO_DEVICE);

                /* Check tx error on the last segment */
                if (desc_get_tx_ls(p)) {
                        desc_get_tx_status(priv, p);
                        dev_consume_skb_any(skb);
                }

                priv->tx_skbuff[entry] = NULL;
                priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);
        }

        /* Ensure tx_tail is visible to xgmac_xmit */
        smp_mb();
        if (unlikely(netif_queue_stopped(priv->dev) &&
            (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)))
                netif_wake_queue(priv->dev);
}

static void xgmac_tx_timeout_work(struct work_struct *work)
{
        u32 reg, value;
        struct xgmac_priv *priv =
                container_of(work, struct xgmac_priv, tx_timeout_work);

        napi_disable(&priv->napi);

        writel(0, priv->base + XGMAC_DMA_INTR_ENA);

        netif_tx_lock(priv->dev);

        reg = readl(priv->base + XGMAC_DMA_CONTROL);
        writel(reg & ~DMA_CONTROL_ST, priv->base + XGMAC_DMA_CONTROL);
        do {
                value = readl(priv->base + XGMAC_DMA_STATUS) & 0x700000;
        } while (value && (value != 0x600000));

        xgmac_free_tx_skbufs(priv);
        desc_init_tx_desc(priv->dma_tx, DMA_TX_RING_SZ);
        priv->tx_tail = 0;
        priv->tx_head = 0;
        writel(priv->dma_tx_phy, priv->base + XGMAC_DMA_TX_BASE_ADDR);
        writel(reg | DMA_CONTROL_ST, priv->base + XGMAC_DMA_CONTROL);

        writel(DMA_STATUS_TU | DMA_STATUS_TPS | DMA_STATUS_NIS | DMA_STATUS_AIS,
                priv->base + XGMAC_DMA_STATUS);

        netif_tx_unlock(priv->dev);
        netif_wake_queue(priv->dev);

        napi_enable(&priv->napi);

        /* Enable interrupts */
        writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_STATUS);
        writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
}

static int xgmac_hw_init(struct net_device *dev)
{
        u32 value, ctrl;
        int limit;
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;

        /* Save the ctrl register value */
        ctrl = readl(ioaddr + XGMAC_CONTROL) & XGMAC_CONTROL_SPD_MASK;

        /* SW reset */
        value = DMA_BUS_MODE_SFT_RESET;
        writel(value, ioaddr + XGMAC_DMA_BUS_MODE);
        limit = 15000;
        while (limit-- &&
                (readl(ioaddr + XGMAC_DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
                cpu_relax();
        if (limit < 0)
                return -EBUSY;

        value = (0x10 << DMA_BUS_MODE_PBL_SHIFT) |
                (0x10 << DMA_BUS_MODE_RPBL_SHIFT) |
                DMA_BUS_MODE_FB | DMA_BUS_MODE_ATDS | DMA_BUS_MODE_AAL;
        writel(value, ioaddr + XGMAC_DMA_BUS_MODE);

        writel(0, ioaddr + XGMAC_DMA_INTR_ENA);

        /* Mask power mgt interrupt */
        writel(XGMAC_INT_STAT_PMTIM, ioaddr + XGMAC_INT_STAT);

        /* XGMAC requires AXI bus init. This is a 'magic number' for now */
        writel(0x0077000E, ioaddr + XGMAC_DMA_AXI_BUS);

        ctrl |= XGMAC_CONTROL_DDIC | XGMAC_CONTROL_JE | XGMAC_CONTROL_ACS |
                XGMAC_CONTROL_CAR;
        if (dev->features & NETIF_F_RXCSUM)
                ctrl |= XGMAC_CONTROL_IPC;
        writel(ctrl, ioaddr + XGMAC_CONTROL);

        writel(DMA_CONTROL_OSF, ioaddr + XGMAC_DMA_CONTROL);

        /* Set the HW DMA mode and the COE */
        writel(XGMAC_OMR_TSF | XGMAC_OMR_RFD | XGMAC_OMR_RFA |
                XGMAC_OMR_RTC_256,
                ioaddr + XGMAC_OMR);

        /* Reset the MMC counters */
        writel(1, ioaddr + XGMAC_MMC_CTRL);
        return 0;
}

/**
 *  xgmac_open - open entry point of the driver
 *  @dev : pointer to the device structure.
 *  Description:
 *  This function is the open entry point of the driver.
 *  Return value:
 *  0 on success and an appropriate (-)ve integer as defined in errno.h
 *  file on failure.

 */
static int xgmac_open(struct net_device *dev)
{
        int ret;
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;

        /* Check that the MAC address is valid.  If its not, refuse
         * to bring the device up. The user must specify an
         * address using the following linux command:
         *      ifconfig eth0 hw ether xx:xx:xx:xx:xx:xx  */
        if (!is_valid_ether_addr(dev->dev_addr)) {
                eth_hw_addr_random(dev);
                netdev_dbg(priv->dev, "generated random MAC address %pM\n",
                        dev->dev_addr);
        }

        memset(&priv->xstats, 0, sizeof(struct xgmac_extra_stats));

        /* Initialize the XGMAC and descriptors */
        xgmac_hw_init(dev);
        xgmac_set_mac_addr(ioaddr, dev->dev_addr, 0);
        xgmac_set_flow_ctrl(priv, priv->rx_pause, priv->tx_pause);

        ret = xgmac_dma_desc_rings_init(dev);
        if (ret < 0)
                return ret;

        /* Enable the MAC Rx/Tx */
        xgmac_mac_enable(ioaddr);

        napi_enable(&priv->napi);
        netif_start_queue(dev);

        /* Enable interrupts */
        writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
        writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);

        return 0;
}

/**
 *  xgmac_stop - close entry point of the driver
 *  @dev : device pointer.
 *  Description:
 *  This is the stop entry point of the driver.
 */
static int xgmac_stop(struct net_device *dev)
{
        struct xgmac_priv *priv = netdev_priv(dev);

        if (readl(priv->base + XGMAC_DMA_INTR_ENA))
                napi_disable(&priv->napi);

        writel(0, priv->base + XGMAC_DMA_INTR_ENA);

        netif_tx_disable(dev);

        /* Disable the MAC core */
        xgmac_mac_disable(priv->base);

        /* Release and free the Rx/Tx resources */
        xgmac_free_dma_desc_rings(priv);

        return 0;
}

/**
 *  xgmac_xmit:
 *  @skb : the socket buffer
 *  @dev : device pointer
 *  Description : Tx entry point of the driver.
 */
static netdev_tx_t xgmac_xmit(struct sk_buff *skb, struct net_device *dev)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        unsigned int entry;
        int i;
        u32 irq_flag;
        int nfrags = skb_shinfo(skb)->nr_frags;
        struct xgmac_dma_desc *desc, *first;
        unsigned int desc_flags;
        unsigned int len;
        dma_addr_t paddr;

        priv->tx_irq_cnt = (priv->tx_irq_cnt + 1) & (DMA_TX_RING_SZ/4 - 1);
        irq_flag = priv->tx_irq_cnt ? 0 : TXDESC_INTERRUPT;

        desc_flags = (skb->ip_summed == CHECKSUM_PARTIAL) ?
                TXDESC_CSUM_ALL : 0;
        entry = priv->tx_head;
        desc = priv->dma_tx + entry;
        first = desc;

        len = skb_headlen(skb);
        paddr = dma_map_single(priv->device, skb->data, len, DMA_TO_DEVICE);
        if (dma_mapping_error(priv->device, paddr)) {
                dev_kfree_skb_any(skb);
                return NETDEV_TX_OK;
        }
        priv->tx_skbuff[entry] = skb;
        desc_set_buf_addr_and_size(desc, paddr, len);

        for (i = 0; i < nfrags; i++) {
                skb_frag_t *frag = &skb_shinfo(skb)->frags[i];

                len = skb_frag_size(frag);

                paddr = skb_frag_dma_map(priv->device, frag, 0, len,
                                         DMA_TO_DEVICE);
                if (dma_mapping_error(priv->device, paddr))
                        goto dma_err;

                entry = dma_ring_incr(entry, DMA_TX_RING_SZ);
                desc = priv->dma_tx + entry;
                priv->tx_skbuff[entry] = skb;

                desc_set_buf_addr_and_size(desc, paddr, len);
                if (i < (nfrags - 1))
                        desc_set_tx_owner(desc, desc_flags);
        }

        /* Interrupt on completition only for the latest segment */
        if (desc != first)
                desc_set_tx_owner(desc, desc_flags |
                        TXDESC_LAST_SEG | irq_flag);
        else
                desc_flags |= TXDESC_LAST_SEG | irq_flag;

        /* Set owner on first desc last to avoid race condition */
        wmb();
        desc_set_tx_owner(first, desc_flags | TXDESC_FIRST_SEG);

        writel(1, priv->base + XGMAC_DMA_TX_POLL);

        priv->tx_head = dma_ring_incr(entry, DMA_TX_RING_SZ);

        /* Ensure tx_head update is visible to tx completion */
        smp_mb();
        if (unlikely(tx_dma_ring_space(priv) <= MAX_SKB_FRAGS)) {
                netif_stop_queue(dev);
                /* Ensure netif_stop_queue is visible to tx completion */
                smp_mb();
                if (tx_dma_ring_space(priv) > MAX_SKB_FRAGS)
                        netif_start_queue(dev);
        }
        return NETDEV_TX_OK;

dma_err:
        entry = priv->tx_head;
        for ( ; i > 0; i--) {
                entry = dma_ring_incr(entry, DMA_TX_RING_SZ);
                desc = priv->dma_tx + entry;
                priv->tx_skbuff[entry] = NULL;
                dma_unmap_page(priv->device, desc_get_buf_addr(desc),
                               desc_get_buf_len(desc), DMA_TO_DEVICE);
                desc_clear_tx_owner(desc);
        }
        desc = first;
        dma_unmap_single(priv->device, desc_get_buf_addr(desc),
                         desc_get_buf_len(desc), DMA_TO_DEVICE);
        dev_kfree_skb_any(skb);
        return NETDEV_TX_OK;
}

static int xgmac_rx(struct xgmac_priv *priv, int limit)
{
        unsigned int entry;
        unsigned int count = 0;
        struct xgmac_dma_desc *p;

        while (count < limit) {
                int ip_checksum;
                struct sk_buff *skb;
                int frame_len;

                if (!dma_ring_cnt(priv->rx_head, priv->rx_tail, DMA_RX_RING_SZ))
                        break;

                entry = priv->rx_tail;
                p = priv->dma_rx + entry;
                if (desc_get_owner(p))
                        break;

                count++;
                priv->rx_tail = dma_ring_incr(priv->rx_tail, DMA_RX_RING_SZ);

                /* read the status of the incoming frame */
                ip_checksum = desc_get_rx_status(priv, p);
                if (ip_checksum < 0)
                        continue;

                skb = priv->rx_skbuff[entry];
                if (unlikely(!skb)) {
                        netdev_err(priv->dev, "Inconsistent Rx descriptor chain\n");
                        break;
                }
                priv->rx_skbuff[entry] = NULL;

                frame_len = desc_get_rx_frame_len(p);
                netdev_dbg(priv->dev, "RX frame size %d, COE status: %d\n",
                        frame_len, ip_checksum);

                skb_put(skb, frame_len);
                dma_unmap_single(priv->device, desc_get_buf_addr(p),
                                 priv->dma_buf_sz - NET_IP_ALIGN, DMA_FROM_DEVICE);

                skb->protocol = eth_type_trans(skb, priv->dev);
                skb->ip_summed = ip_checksum;
                if (ip_checksum == CHECKSUM_NONE)
                        netif_receive_skb(skb);
                else
                        napi_gro_receive(&priv->napi, skb);
        }

        xgmac_rx_refill(priv);

        return count;
}

/**
 *  xgmac_poll - xgmac poll method (NAPI)
 *  @napi : pointer to the napi structure.
 *  @budget : maximum number of packets that the current CPU can receive from
 *            all interfaces.
 *  Description :
 *   This function implements the the reception process.
 *   Also it runs the TX completion thread
 */
static int xgmac_poll(struct napi_struct *napi, int budget)
{
        struct xgmac_priv *priv = container_of(napi,
                                       struct xgmac_priv, napi);
        int work_done = 0;

        xgmac_tx_complete(priv);
        work_done = xgmac_rx(priv, budget);

        if (work_done < budget) {
                napi_complete_done(napi, work_done);
                __raw_writel(DMA_INTR_DEFAULT_MASK, priv->base + XGMAC_DMA_INTR_ENA);
        }
        return work_done;
}

/**
 *  xgmac_tx_timeout
 *  @dev : Pointer to net device structure
 *  @txqueue: index of the hung transmit queue
 *
 *  Description: this function is called when a packet transmission fails to
 *   complete within a reasonable tmrate. The driver will mark the error in the
 *   netdev structure and arrange for the device to be reset to a sane state
 *   in order to transmit a new packet.
 */
static void xgmac_tx_timeout(struct net_device *dev, unsigned int txqueue)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        schedule_work(&priv->tx_timeout_work);
}

/**
 *  xgmac_set_rx_mode - entry point for multicast addressing
 *  @dev : pointer to the device structure
 *  Description:
 *  This function is a driver entry point which gets called by the kernel
 *  whenever multicast addresses must be enabled/disabled.
 *  Return value:
 *  void.
 */
static void xgmac_set_rx_mode(struct net_device *dev)
{
        int i;
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;
        unsigned int value = 0;
        u32 hash_filter[XGMAC_NUM_HASH];
        int reg = 1;
        struct netdev_hw_addr *ha;
        bool use_hash = false;

        netdev_dbg(priv->dev, "# mcasts %d, # unicast %d\n",
                 netdev_mc_count(dev), netdev_uc_count(dev));

        if (dev->flags & IFF_PROMISC)
                value |= XGMAC_FRAME_FILTER_PR;

        memset(hash_filter, 0, sizeof(hash_filter));

        if (netdev_uc_count(dev) > priv->max_macs) {
                use_hash = true;
                value |= XGMAC_FRAME_FILTER_HUC | XGMAC_FRAME_FILTER_HPF;
        }
        netdev_for_each_uc_addr(ha, dev) {
                if (use_hash) {
                        u32 bit_nr = ~ether_crc(ETH_ALEN, ha->addr) >> 23;

                        /* The most significant 4 bits determine the register to
                         * use (H/L) while the other 5 bits determine the bit
                         * within the register. */
                        hash_filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
                } else {
                        xgmac_set_mac_addr(ioaddr, ha->addr, reg);
                        reg++;
                }
        }

        if (dev->flags & IFF_ALLMULTI) {
                value |= XGMAC_FRAME_FILTER_PM;
                goto out;
        }

        if ((netdev_mc_count(dev) + reg - 1) > priv->max_macs) {
                use_hash = true;
                value |= XGMAC_FRAME_FILTER_HMC | XGMAC_FRAME_FILTER_HPF;
        } else {
                use_hash = false;
        }
        netdev_for_each_mc_addr(ha, dev) {
                if (use_hash) {
                        u32 bit_nr = ~ether_crc(ETH_ALEN, ha->addr) >> 23;

                        /* The most significant 4 bits determine the register to
                         * use (H/L) while the other 5 bits determine the bit
                         * within the register. */
                        hash_filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
                } else {
                        xgmac_set_mac_addr(ioaddr, ha->addr, reg);
                        reg++;
                }
        }

out:
        for (i = reg; i <= priv->max_macs; i++)
                xgmac_set_mac_addr(ioaddr, NULL, i);
        for (i = 0; i < XGMAC_NUM_HASH; i++)
                writel(hash_filter[i], ioaddr + XGMAC_HASH(i));

        writel(value, ioaddr + XGMAC_FRAME_FILTER);
}

/**
 *  xgmac_change_mtu - entry point to change MTU size for the device.
 *  @dev : device pointer.
 *  @new_mtu : the new MTU size for the device.
 *  Description: the Maximum Transfer Unit (MTU) is used by the network layer
 *  to drive packet transmission. Ethernet has an MTU of 1500 octets
 *  (ETH_DATA_LEN). This value can be changed with ifconfig.
 *  Return value:
 *  0 on success and an appropriate (-)ve integer as defined in errno.h
 *  file on failure.
 */
static int xgmac_change_mtu(struct net_device *dev, int new_mtu)
{
        /* Stop everything, get ready to change the MTU */
        if (!netif_running(dev))
                return 0;

        /* Bring interface down, change mtu and bring interface back up */
        xgmac_stop(dev);
        dev->mtu = new_mtu;
        return xgmac_open(dev);
}

static irqreturn_t xgmac_pmt_interrupt(int irq, void *dev_id)
{
        u32 intr_status;
        struct net_device *dev = (struct net_device *)dev_id;
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;

        intr_status = __raw_readl(ioaddr + XGMAC_INT_STAT);
        if (intr_status & XGMAC_INT_STAT_PMT) {
                netdev_dbg(priv->dev, "received Magic frame\n");
                /* clear the PMT bits 5 and 6 by reading the PMT */
                readl(ioaddr + XGMAC_PMT);
        }
        return IRQ_HANDLED;
}

static irqreturn_t xgmac_interrupt(int irq, void *dev_id)
{
        u32 intr_status;
        struct net_device *dev = (struct net_device *)dev_id;
        struct xgmac_priv *priv = netdev_priv(dev);
        struct xgmac_extra_stats *x = &priv->xstats;

        /* read the status register (CSR5) */
        intr_status = __raw_readl(priv->base + XGMAC_DMA_STATUS);
        intr_status &= __raw_readl(priv->base + XGMAC_DMA_INTR_ENA);
        __raw_writel(intr_status, priv->base + XGMAC_DMA_STATUS);

        /* It displays the DMA process states (CSR5 register) */
        /* ABNORMAL interrupts */
        if (unlikely(intr_status & DMA_STATUS_AIS)) {
                if (intr_status & DMA_STATUS_TJT) {
                        netdev_err(priv->dev, "transmit jabber\n");
                        x->tx_jabber++;
                }
                if (intr_status & DMA_STATUS_RU)
                        x->rx_buf_unav++;
                if (intr_status & DMA_STATUS_RPS) {
                        netdev_err(priv->dev, "receive process stopped\n");
                        x->rx_process_stopped++;
                }
                if (intr_status & DMA_STATUS_ETI) {
                        netdev_err(priv->dev, "transmit early interrupt\n");
                        x->tx_early++;
                }
                if (intr_status & DMA_STATUS_TPS) {
                        netdev_err(priv->dev, "transmit process stopped\n");
                        x->tx_process_stopped++;
                        schedule_work(&priv->tx_timeout_work);
                }
                if (intr_status & DMA_STATUS_FBI) {
                        netdev_err(priv->dev, "fatal bus error\n");
                        x->fatal_bus_error++;
                }
        }

        /* TX/RX NORMAL interrupts */
        if (intr_status & (DMA_STATUS_RI | DMA_STATUS_TU | DMA_STATUS_TI)) {
                __raw_writel(DMA_INTR_ABNORMAL, priv->base + XGMAC_DMA_INTR_ENA);
                napi_schedule(&priv->napi);
        }

        return IRQ_HANDLED;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
/* Polling receive - used by NETCONSOLE and other diagnostic tools
 * to allow network I/O with interrupts disabled. */
static void xgmac_poll_controller(struct net_device *dev)
{
        disable_irq(dev->irq);
        xgmac_interrupt(dev->irq, dev);
        enable_irq(dev->irq);
}
#endif

static void
xgmac_get_stats64(struct net_device *dev,
                  struct rtnl_link_stats64 *storage)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *base = priv->base;
        u32 count;

        spin_lock_bh(&priv->stats_lock);
        writel(XGMAC_MMC_CTRL_CNT_FRZ, base + XGMAC_MMC_CTRL);

        storage->rx_bytes = readl(base + XGMAC_MMC_RXOCTET_G_LO);
        storage->rx_bytes |= (u64)(readl(base + XGMAC_MMC_RXOCTET_G_HI)) << 32;

        storage->rx_packets = readl(base + XGMAC_MMC_RXFRAME_GB_LO);
        storage->multicast = readl(base + XGMAC_MMC_RXMCFRAME_G);
        storage->rx_crc_errors = readl(base + XGMAC_MMC_RXCRCERR);
        storage->rx_length_errors = readl(base + XGMAC_MMC_RXLENGTHERR);
        storage->rx_missed_errors = readl(base + XGMAC_MMC_RXOVERFLOW);

        storage->tx_bytes = readl(base + XGMAC_MMC_TXOCTET_G_LO);
        storage->tx_bytes |= (u64)(readl(base + XGMAC_MMC_TXOCTET_G_HI)) << 32;

        count = readl(base + XGMAC_MMC_TXFRAME_GB_LO);
        storage->tx_errors = count - readl(base + XGMAC_MMC_TXFRAME_G_LO);
        storage->tx_packets = count;
        storage->tx_fifo_errors = readl(base + XGMAC_MMC_TXUNDERFLOW);

        writel(0, base + XGMAC_MMC_CTRL);
        spin_unlock_bh(&priv->stats_lock);
}

static int xgmac_set_mac_address(struct net_device *dev, void *p)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;
        struct sockaddr *addr = p;

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

        memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);

        xgmac_set_mac_addr(ioaddr, dev->dev_addr, 0);

        return 0;
}

static int xgmac_set_features(struct net_device *dev, netdev_features_t features)
{
        u32 ctrl;
        struct xgmac_priv *priv = netdev_priv(dev);
        void __iomem *ioaddr = priv->base;
        netdev_features_t changed = dev->features ^ features;

        if (!(changed & NETIF_F_RXCSUM))
                return 0;

        ctrl = readl(ioaddr + XGMAC_CONTROL);
        if (features & NETIF_F_RXCSUM)
                ctrl |= XGMAC_CONTROL_IPC;
        else
                ctrl &= ~XGMAC_CONTROL_IPC;
        writel(ctrl, ioaddr + XGMAC_CONTROL);

        return 0;
}

static const struct net_device_ops xgmac_netdev_ops = {
        .ndo_open = xgmac_open,
        .ndo_start_xmit = xgmac_xmit,
        .ndo_stop = xgmac_stop,
        .ndo_change_mtu = xgmac_change_mtu,
        .ndo_set_rx_mode = xgmac_set_rx_mode,
        .ndo_tx_timeout = xgmac_tx_timeout,
        .ndo_get_stats64 = xgmac_get_stats64,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller = xgmac_poll_controller,
#endif
        .ndo_set_mac_address = xgmac_set_mac_address,
        .ndo_set_features = xgmac_set_features,
};

static int xgmac_ethtool_get_link_ksettings(struct net_device *dev,
                                            struct ethtool_link_ksettings *cmd)
{
        cmd->base.autoneg = 0;
        cmd->base.duplex = DUPLEX_FULL;
        cmd->base.speed = 10000;
        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.supported, 0);
        ethtool_convert_legacy_u32_to_link_mode(cmd->link_modes.advertising, 0);
        return 0;
}

static void xgmac_get_pauseparam(struct net_device *netdev,
                                      struct ethtool_pauseparam *pause)
{
        struct xgmac_priv *priv = netdev_priv(netdev);

        pause->rx_pause = priv->rx_pause;
        pause->tx_pause = priv->tx_pause;
}

static int xgmac_set_pauseparam(struct net_device *netdev,
                                     struct ethtool_pauseparam *pause)
{
        struct xgmac_priv *priv = netdev_priv(netdev);

        if (pause->autoneg)
                return -EINVAL;

        return xgmac_set_flow_ctrl(priv, pause->rx_pause, pause->tx_pause);
}

struct xgmac_stats {
        char stat_string[ETH_GSTRING_LEN];
        int stat_offset;
        bool is_reg;
};

#define XGMAC_STAT(m)   \
        { #m, offsetof(struct xgmac_priv, xstats.m), false }
#define XGMAC_HW_STAT(m, reg_offset)    \
        { #m, reg_offset, true }

static const struct xgmac_stats xgmac_gstrings_stats[] = {
        XGMAC_STAT(tx_frame_flushed),
        XGMAC_STAT(tx_payload_error),
        XGMAC_STAT(tx_ip_header_error),
        XGMAC_STAT(tx_local_fault),
        XGMAC_STAT(tx_remote_fault),
        XGMAC_STAT(tx_early),
        XGMAC_STAT(tx_process_stopped),
        XGMAC_STAT(tx_jabber),
        XGMAC_STAT(rx_buf_unav),
        XGMAC_STAT(rx_process_stopped),
        XGMAC_STAT(rx_payload_error),
        XGMAC_STAT(rx_ip_header_error),
        XGMAC_STAT(rx_da_filter_fail),
        XGMAC_STAT(fatal_bus_error),
        XGMAC_HW_STAT(rx_watchdog, XGMAC_MMC_RXWATCHDOG),
        XGMAC_HW_STAT(tx_vlan, XGMAC_MMC_TXVLANFRAME),
        XGMAC_HW_STAT(rx_vlan, XGMAC_MMC_RXVLANFRAME),
        XGMAC_HW_STAT(tx_pause, XGMAC_MMC_TXPAUSEFRAME),
        XGMAC_HW_STAT(rx_pause, XGMAC_MMC_RXPAUSEFRAME),
};
#define XGMAC_STATS_LEN ARRAY_SIZE(xgmac_gstrings_stats)

static void xgmac_get_ethtool_stats(struct net_device *dev,
                                         struct ethtool_stats *dummy,
                                         u64 *data)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        void *p = priv;
        int i;

        for (i = 0; i < XGMAC_STATS_LEN; i++) {
                if (xgmac_gstrings_stats[i].is_reg)
                        *data++ = readl(priv->base +
                                xgmac_gstrings_stats[i].stat_offset);
                else
                        *data++ = *(u32 *)(p +
                                xgmac_gstrings_stats[i].stat_offset);
        }
}

static int xgmac_get_sset_count(struct net_device *netdev, int sset)
{
        switch (sset) {
        case ETH_SS_STATS:
                return XGMAC_STATS_LEN;
        default:
                return -EINVAL;
        }
}

static void xgmac_get_strings(struct net_device *dev, u32 stringset,
                                   u8 *data)
{
        int i;
        u8 *p = data;

        switch (stringset) {
        case ETH_SS_STATS:
                for (i = 0; i < XGMAC_STATS_LEN; i++) {
                        memcpy(p, xgmac_gstrings_stats[i].stat_string,
                               ETH_GSTRING_LEN);
                        p += ETH_GSTRING_LEN;
                }
                break;
        default:
                WARN_ON(1);
                break;
        }
}

static void xgmac_get_wol(struct net_device *dev,
                               struct ethtool_wolinfo *wol)
{
        struct xgmac_priv *priv = netdev_priv(dev);

        if (device_can_wakeup(priv->device)) {
                wol->supported = WAKE_MAGIC | WAKE_UCAST;
                wol->wolopts = priv->wolopts;
        }
}

static int xgmac_set_wol(struct net_device *dev,
                              struct ethtool_wolinfo *wol)
{
        struct xgmac_priv *priv = netdev_priv(dev);
        u32 support = WAKE_MAGIC | WAKE_UCAST;

        if (!device_can_wakeup(priv->device))
                return -ENOTSUPP;

        if (wol->wolopts & ~support)
                return -EINVAL;

        priv->wolopts = wol->wolopts;

        if (wol->wolopts) {
                device_set_wakeup_enable(priv->device, 1);
                enable_irq_wake(dev->irq);
        } else {
                device_set_wakeup_enable(priv->device, 0);
                disable_irq_wake(dev->irq);
        }

        return 0;
}

static const struct ethtool_ops xgmac_ethtool_ops = {
        .get_link = ethtool_op_get_link,
        .get_pauseparam = xgmac_get_pauseparam,
        .set_pauseparam = xgmac_set_pauseparam,
        .get_ethtool_stats = xgmac_get_ethtool_stats,
        .get_strings = xgmac_get_strings,
        .get_wol = xgmac_get_wol,
        .set_wol = xgmac_set_wol,
        .get_sset_count = xgmac_get_sset_count,
        .get_link_ksettings = xgmac_ethtool_get_link_ksettings,
};

/**
 * xgmac_probe
 * @pdev: platform device pointer
 * Description: the driver is initialized through platform_device.
 */
static int xgmac_probe(struct platform_device *pdev)
{
        int ret = 0;
        struct resource *res;
        struct net_device *ndev = NULL;
        struct xgmac_priv *priv = NULL;
        u32 uid;

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;

        if (!request_mem_region(res->start, resource_size(res), pdev->name))
                return -EBUSY;

        ndev = alloc_etherdev(sizeof(struct xgmac_priv));
        if (!ndev) {
                ret = -ENOMEM;
                goto err_alloc;
        }

        SET_NETDEV_DEV(ndev, &pdev->dev);
        priv = netdev_priv(ndev);
        platform_set_drvdata(pdev, ndev);
        ndev->netdev_ops = &xgmac_netdev_ops;
        ndev->ethtool_ops = &xgmac_ethtool_ops;
        spin_lock_init(&priv->stats_lock);
        INIT_WORK(&priv->tx_timeout_work, xgmac_tx_timeout_work);

        priv->device = &pdev->dev;
        priv->dev = ndev;
        priv->rx_pause = 1;
        priv->tx_pause = 1;

        priv->base = ioremap(res->start, resource_size(res));
        if (!priv->base) {
                netdev_err(ndev, "ioremap failed\n");
                ret = -ENOMEM;
                goto err_io;
        }

        uid = readl(priv->base + XGMAC_VERSION);
        netdev_info(ndev, "h/w version is 0x%x\n", uid);

        /* Figure out how many valid mac address filter registers we have */
        writel(1, priv->base + XGMAC_ADDR_HIGH(31));
        if (readl(priv->base + XGMAC_ADDR_HIGH(31)) == 1)
                priv->max_macs = 31;
        else
                priv->max_macs = 7;

        writel(0, priv->base + XGMAC_DMA_INTR_ENA);
        ndev->irq = platform_get_irq(pdev, 0);
        if (ndev->irq == -ENXIO) {
                netdev_err(ndev, "No irq resource\n");
                ret = ndev->irq;
                goto err_irq;
        }

        ret = request_irq(ndev->irq, xgmac_interrupt, 0,
                          dev_name(&pdev->dev), ndev);
        if (ret < 0) {
                netdev_err(ndev, "Could not request irq %d - ret %d)\n",
                        ndev->irq, ret);
                goto err_irq;
        }

        priv->pmt_irq = platform_get_irq(pdev, 1);
        if (priv->pmt_irq == -ENXIO) {
                netdev_err(ndev, "No pmt irq resource\n");
                ret = priv->pmt_irq;
                goto err_pmt_irq;
        }

        ret = request_irq(priv->pmt_irq, xgmac_pmt_interrupt, 0,
                          dev_name(&pdev->dev), ndev);
        if (ret < 0) {
                netdev_err(ndev, "Could not request irq %d - ret %d)\n",
                        priv->pmt_irq, ret);
                goto err_pmt_irq;
        }

        device_set_wakeup_capable(&pdev->dev, 1);
        if (device_can_wakeup(priv->device))
                priv->wolopts = WAKE_MAGIC;     /* Magic Frame as default */

        ndev->hw_features = NETIF_F_SG | NETIF_F_HIGHDMA;
        if (readl(priv->base + XGMAC_DMA_HW_FEATURE) & DMA_HW_FEAT_TXCOESEL)
                ndev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
                                     NETIF_F_RXCSUM;
        ndev->features |= ndev->hw_features;
        ndev->priv_flags |= IFF_UNICAST_FLT;

        /* MTU range: 46 - 9000 */
        ndev->min_mtu = ETH_ZLEN - ETH_HLEN;
        ndev->max_mtu = XGMAC_MAX_MTU;

        /* Get the MAC address */
        xgmac_get_mac_addr(priv->base, ndev->dev_addr, 0);
        if (!is_valid_ether_addr(ndev->dev_addr))
                netdev_warn(ndev, "MAC address %pM not valid",
                         ndev->dev_addr);

        netif_napi_add(ndev, &priv->napi, xgmac_poll, 64);
        ret = register_netdev(ndev);
        if (ret)
                goto err_reg;

        return 0;

err_reg:
        netif_napi_del(&priv->napi);
        free_irq(priv->pmt_irq, ndev);
err_pmt_irq:
        free_irq(ndev->irq, ndev);
err_irq:
        iounmap(priv->base);
err_io:
        free_netdev(ndev);
err_alloc:
        release_mem_region(res->start, resource_size(res));
        return ret;
}

/**
 * xgmac_remove
 * @pdev: platform device pointer
 * Description: this function resets the TX/RX processes, disables the MAC RX/TX
 * changes the link status, releases the DMA descriptor rings,
 * unregisters the MDIO bus and unmaps the allocated memory.
 */
static int xgmac_remove(struct platform_device *pdev)
{
        struct net_device *ndev = platform_get_drvdata(pdev);
        struct xgmac_priv *priv = netdev_priv(ndev);
        struct resource *res;

        xgmac_mac_disable(priv->base);

        /* Free the IRQ lines */
        free_irq(ndev->irq, ndev);
        free_irq(priv->pmt_irq, ndev);

        unregister_netdev(ndev);
        netif_napi_del(&priv->napi);

        iounmap(priv->base);
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        release_mem_region(res->start, resource_size(res));

        free_netdev(ndev);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static void xgmac_pmt(void __iomem *ioaddr, unsigned long mode)
{
        unsigned int pmt = 0;

        if (mode & WAKE_MAGIC)
                pmt |= XGMAC_PMT_POWERDOWN | XGMAC_PMT_MAGIC_PKT_EN;
        if (mode & WAKE_UCAST)
                pmt |= XGMAC_PMT_POWERDOWN | XGMAC_PMT_GLBL_UNICAST;

        writel(pmt, ioaddr + XGMAC_PMT);
}

static int xgmac_suspend(struct device *dev)
{
        struct net_device *ndev = dev_get_drvdata(dev);
        struct xgmac_priv *priv = netdev_priv(ndev);
        u32 value;

        if (!ndev || !netif_running(ndev))
                return 0;

        netif_device_detach(ndev);
        napi_disable(&priv->napi);
        writel(0, priv->base + XGMAC_DMA_INTR_ENA);

        if (device_may_wakeup(priv->device)) {
                /* Stop TX/RX DMA Only */
                value = readl(priv->base + XGMAC_DMA_CONTROL);
                value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
                writel(value, priv->base + XGMAC_DMA_CONTROL);

                xgmac_pmt(priv->base, priv->wolopts);
        } else
                xgmac_mac_disable(priv->base);

        return 0;
}

static int xgmac_resume(struct device *dev)
{
        struct net_device *ndev = dev_get_drvdata(dev);
        struct xgmac_priv *priv = netdev_priv(ndev);
        void __iomem *ioaddr = priv->base;

        if (!netif_running(ndev))
                return 0;

        xgmac_pmt(ioaddr, 0);

        /* Enable the MAC and DMA */
        xgmac_mac_enable(ioaddr);
        writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
        writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);

        netif_device_attach(ndev);
        napi_enable(&priv->napi);

        return 0;
}
#endif /* CONFIG_PM_SLEEP */

static SIMPLE_DEV_PM_OPS(xgmac_pm_ops, xgmac_suspend, xgmac_resume);

static const struct of_device_id xgmac_of_match[] = {
        { .compatible = "calxeda,hb-xgmac", },
        {},
};
MODULE_DEVICE_TABLE(of, xgmac_of_match);

static struct platform_driver xgmac_driver = {
        .driver = {
                .name = "calxedaxgmac",
                .of_match_table = xgmac_of_match,
                .pm = &xgmac_pm_ops,
        },
        .probe = xgmac_probe,
        .remove = xgmac_remove,
};

module_platform_driver(xgmac_driver);

MODULE_AUTHOR("Calxeda, Inc.");
MODULE_DESCRIPTION("Calxeda 10G XGMAC driver");
MODULE_LICENSE("GPL v2");