/*
 * Micrel KS8851_MLL 16bit Network driver
 * Copyright (c) 2011 Roberto Cerati <roberto.cerati@bticino.it>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <asm/io.h>
#include <common.h>
#include <command.h>
#include <malloc.h>
#include <net.h>
#include <miiphy.h>

#include "ks8851_mll.h"

#define DRIVERNAME                      "ks8851_mll"

#define MAX_RECV_FRAMES                 32
#define MAX_BUF_SIZE                    2048
#define TX_BUF_SIZE                     2000
#define RX_BUF_SIZE                     2000

static const struct chip_id chip_ids[] =  {
        {CIDER_ID, "KSZ8851"},
        {0, NULL},
};

/*
 * union ks_tx_hdr - tx header data
 * @txb: The header as bytes
 * @txw: The header as 16bit, little-endian words
 *
 * A dual representation of the tx header data to allow
 * access to individual bytes, and to allow 16bit accesses
 * with 16bit alignment.
 */
union ks_tx_hdr {
        u8      txb[4];
        __le16  txw[2];
};

/*
 * struct ks_net - KS8851 driver private data
 * @net_device  : The network device we're bound to
 * @txh         : temporaly buffer to save status/length.
 * @frame_head_info     : frame header information for multi-pkt rx.
 * @statelock   : Lock on this structure for tx list.
 * @msg_enable  : The message flags controlling driver output (see ethtool).
 * @frame_cnt   : number of frames received.
 * @bus_width   : i/o bus width.
 * @irq         : irq number assigned to this device.
 * @rc_rxqcr    : Cached copy of KS_RXQCR.
 * @rc_txcr     : Cached copy of KS_TXCR.
 * @rc_ier      : Cached copy of KS_IER.
 * @sharedbus   : Multipex(addr and data bus) mode indicator.
 * @cmd_reg_cache       : command register cached.
 * @cmd_reg_cache_int   : command register cached. Used in the irq handler.
 * @promiscuous : promiscuous mode indicator.
 * @all_mcast   : mutlicast indicator.
 * @mcast_lst_size      : size of multicast list.
 * @mcast_lst           : multicast list.
 * @mcast_bits          : multicast enabed.
 * @mac_addr            : MAC address assigned to this device.
 * @fid                 : frame id.
 * @extra_byte          : number of extra byte prepended rx pkt.
 * @enabled             : indicator this device works.
 */

/* Receive multiplex framer header info */
struct type_frame_head {
        u16     sts;         /* Frame status */
        u16     len;         /* Byte count */
} fr_h_i[MAX_RECV_FRAMES];

struct ks_net {
        struct net_device       *netdev;
        union ks_tx_hdr         txh;
        struct type_frame_head  *frame_head_info;
        u32                     msg_enable;
        u32                     frame_cnt;
        int                     bus_width;
        int                     irq;
        u16                     rc_rxqcr;
        u16                     rc_txcr;
        u16                     rc_ier;
        u16                     sharedbus;
        u16                     cmd_reg_cache;
        u16                     cmd_reg_cache_int;
        u16                     promiscuous;
        u16                     all_mcast;
        u16                     mcast_lst_size;
        u8                      mcast_lst[MAX_MCAST_LST][MAC_ADDR_LEN];
        u8                      mcast_bits[HW_MCAST_SIZE];
        u8                      mac_addr[6];
        u8                      fid;
        u8                      extra_byte;
        u8                      enabled;
} ks_str, *ks;

#define BE3             0x8000      /* Byte Enable 3 */
#define BE2             0x4000      /* Byte Enable 2 */
#define BE1             0x2000      /* Byte Enable 1 */
#define BE0             0x1000      /* Byte Enable 0 */

static u8 ks_rdreg8(struct eth_device *dev, u16 offset)
{
        u8 shift_bit = offset & 0x03;
        u8 shift_data = (offset & 1) << 3;

        writew(offset | (BE0 << shift_bit), dev->iobase + 2);

        return (u8)(readw(dev->iobase) >> shift_data);
}

static u16 ks_rdreg16(struct eth_device *dev, u16 offset)
{
        writew(offset | ((BE1 | BE0) << (offset & 0x02)), dev->iobase + 2);

        return readw(dev->iobase);
}

static void ks_wrreg8(struct eth_device *dev, u16 offset, u8 val)
{
        u8 shift_bit = (offset & 0x03);
        u16 value_write = (u16)(val << ((offset & 1) << 3));

        writew(offset | (BE0 << shift_bit), dev->iobase + 2);
        writew(value_write, dev->iobase);
}

static void ks_wrreg16(struct eth_device *dev, u16 offset, u16 val)
{
        writew(offset | ((BE1 | BE0) << (offset & 0x02)), dev->iobase + 2);
        writew(val, dev->iobase);
}

/*
 * ks_inblk - read a block of data from QMU. This is called after sudo DMA mode
 * enabled.
 * @ks: The chip state
 * @wptr: buffer address to save data
 * @len: length in byte to read
 */
static inline void ks_inblk(struct eth_device *dev, u16 *wptr, u32 len)
{
        len >>= 1;

        while (len--)
                *wptr++ = readw(dev->iobase);
}

/*
 * ks_outblk - write data to QMU. This is called after sudo DMA mode enabled.
 * @ks: The chip information
 * @wptr: buffer address
 * @len: length in byte to write
 */
static inline void ks_outblk(struct eth_device *dev, u16 *wptr, u32 len)
{
        len >>= 1;

        while (len--)
                writew(*wptr++, dev->iobase);
}

static void ks_enable_int(struct eth_device *dev)
{
        ks_wrreg16(dev, KS_IER, ks->rc_ier);
}

static void ks_set_powermode(struct eth_device *dev, unsigned pwrmode)
{
        unsigned pmecr;

        ks_rdreg16(dev, KS_GRR);
        pmecr = ks_rdreg16(dev, KS_PMECR);
        pmecr &= ~PMECR_PM_MASK;
        pmecr |= pwrmode;

        ks_wrreg16(dev, KS_PMECR, pmecr);
}

/*
 * ks_read_config - read chip configuration of bus width.
 * @ks: The chip information
 */
static void ks_read_config(struct eth_device *dev)
{
        u16 reg_data = 0;

        /* Regardless of bus width, 8 bit read should always work. */
        reg_data = ks_rdreg8(dev, KS_CCR) & 0x00FF;
        reg_data |= ks_rdreg8(dev, KS_CCR + 1) << 8;

        /* addr/data bus are multiplexed */
        ks->sharedbus = (reg_data & CCR_SHARED) == CCR_SHARED;

        /*
         * There are garbage data when reading data from QMU,
         * depending on bus-width.
         */
        if (reg_data & CCR_8BIT) {
                ks->bus_width = ENUM_BUS_8BIT;
                ks->extra_byte = 1;
        } else if (reg_data & CCR_16BIT) {
                ks->bus_width = ENUM_BUS_16BIT;
                ks->extra_byte = 2;
        } else {
                ks->bus_width = ENUM_BUS_32BIT;
                ks->extra_byte = 4;
        }
}

/*
 * ks_soft_reset - issue one of the soft reset to the device
 * @ks: The device state.
 * @op: The bit(s) to set in the GRR
 *
 * Issue the relevant soft-reset command to the device's GRR register
 * specified by @op.
 *
 * Note, the delays are in there as a caution to ensure that the reset
 * has time to take effect and then complete. Since the datasheet does
 * not currently specify the exact sequence, we have chosen something
 * that seems to work with our device.
 */
static void ks_soft_reset(struct eth_device *dev, unsigned op)
{
        /* Disable interrupt first */
        ks_wrreg16(dev, KS_IER, 0x0000);
        ks_wrreg16(dev, KS_GRR, op);
        mdelay(10);     /* wait a short time to effect reset */
        ks_wrreg16(dev, KS_GRR, 0);
        mdelay(1);      /* wait for condition to clear */
}

void ks_enable_qmu(struct eth_device *dev)
{
        u16 w;

        w = ks_rdreg16(dev, KS_TXCR);

        /* Enables QMU Transmit (TXCR). */
        ks_wrreg16(dev, KS_TXCR, w | TXCR_TXE);

        /* Enable RX Frame Count Threshold and Auto-Dequeue RXQ Frame */
        w = ks_rdreg16(dev, KS_RXQCR);
        ks_wrreg16(dev, KS_RXQCR, w | RXQCR_RXFCTE);

        /* Enables QMU Receive (RXCR1). */
        w = ks_rdreg16(dev, KS_RXCR1);
        ks_wrreg16(dev, KS_RXCR1, w | RXCR1_RXE);
}

static void ks_disable_qmu(struct eth_device *dev)
{
        u16 w;

        w = ks_rdreg16(dev, KS_TXCR);

        /* Disables QMU Transmit (TXCR). */
        w &= ~TXCR_TXE;
        ks_wrreg16(dev, KS_TXCR, w);

        /* Disables QMU Receive (RXCR1). */
        w = ks_rdreg16(dev, KS_RXCR1);
        w &= ~RXCR1_RXE;
        ks_wrreg16(dev, KS_RXCR1, w);
}

static inline void ks_read_qmu(struct eth_device *dev, u16 *buf, u32 len)
{
        u32 r = ks->extra_byte & 0x1;
        u32 w = ks->extra_byte - r;

        /* 1. set sudo DMA mode */
        ks_wrreg16(dev, KS_RXFDPR, RXFDPR_RXFPAI);
        ks_wrreg8(dev, KS_RXQCR, (ks->rc_rxqcr | RXQCR_SDA) & 0xff);

        /*
         * 2. read prepend data
         *
         * read 4 + extra bytes and discard them.
         * extra bytes for dummy, 2 for status, 2 for len
         */

        if (r)
                ks_rdreg8(dev, 0);

        ks_inblk(dev, buf, w + 2 + 2);

        /* 3. read pkt data */
        ks_inblk(dev, buf, ALIGN(len, 4));

        /* 4. reset sudo DMA Mode */
        ks_wrreg8(dev, KS_RXQCR, (ks->rc_rxqcr & ~RXQCR_SDA) & 0xff);
}

static void ks_rcv(struct eth_device *dev, uchar **pv_data)
{
        struct type_frame_head *frame_hdr = ks->frame_head_info;
        int i;

        ks->frame_cnt = ks_rdreg16(dev, KS_RXFCTR) >> 8;

        /* read all header information */
        for (i = 0; i < ks->frame_cnt; i++) {
                /* Checking Received packet status */
                frame_hdr->sts = ks_rdreg16(dev, KS_RXFHSR);
                /* Get packet len from hardware */
                frame_hdr->len = ks_rdreg16(dev, KS_RXFHBCR);
                frame_hdr++;
        }

        frame_hdr = ks->frame_head_info;
        while (ks->frame_cnt--) {
                if ((frame_hdr->sts & RXFSHR_RXFV) &&
                    (frame_hdr->len < RX_BUF_SIZE) &&
                    frame_hdr->len) {
                        /* read data block including CRC 4 bytes */
                        ks_read_qmu(dev, (u16 *)(*pv_data), frame_hdr->len);

                        /* net_rx_packets buffer size is ok (*pv_data) */
                        net_process_received_packet(*pv_data, frame_hdr->len);
                        pv_data++;
                } else {
                        ks_wrreg16(dev, KS_RXQCR, (ks->rc_rxqcr | RXQCR_RRXEF));
                        printf(DRIVERNAME ": bad packet\n");
                }
                frame_hdr++;
        }
}

/*
 * ks_read_selftest - read the selftest memory info.
 * @ks: The device state
 *
 * Read and check the TX/RX memory selftest information.
 */
static int ks_read_selftest(struct eth_device *dev)
{
        u16 both_done = MBIR_TXMBF | MBIR_RXMBF;
        u16 mbir;
        int ret = 0;

        mbir = ks_rdreg16(dev, KS_MBIR);

        if ((mbir & both_done) != both_done) {
                printf(DRIVERNAME ": Memory selftest not finished\n");
                return 0;
        }

        if (mbir & MBIR_TXMBFA) {
                printf(DRIVERNAME ": TX memory selftest fails\n");
                ret |= 1;
        }

        if (mbir & MBIR_RXMBFA) {
                printf(DRIVERNAME ": RX memory selftest fails\n");
                ret |= 2;
        }

        debug(DRIVERNAME ": the selftest passes\n");

        return ret;
}

static void ks_setup(struct eth_device *dev)
{
        u16 w;

        /* Setup Transmit Frame Data Pointer Auto-Increment (TXFDPR) */
        ks_wrreg16(dev, KS_TXFDPR, TXFDPR_TXFPAI);

        /* Setup Receive Frame Data Pointer Auto-Increment */
        ks_wrreg16(dev, KS_RXFDPR, RXFDPR_RXFPAI);

        /* Setup Receive Frame Threshold - 1 frame (RXFCTFC) */
        ks_wrreg16(dev, KS_RXFCTR, 1 & RXFCTR_THRESHOLD_MASK);

        /* Setup RxQ Command Control (RXQCR) */
        ks->rc_rxqcr = RXQCR_CMD_CNTL;
        ks_wrreg16(dev, KS_RXQCR, ks->rc_rxqcr);

        /*
         * set the force mode to half duplex, default is full duplex
         * because if the auto-negotiation fails, most switch uses
         * half-duplex.
         */
        w = ks_rdreg16(dev, KS_P1MBCR);
        w &= ~P1MBCR_FORCE_FDX;
        ks_wrreg16(dev, KS_P1MBCR, w);

        w = TXCR_TXFCE | TXCR_TXPE | TXCR_TXCRC | TXCR_TCGIP;
        ks_wrreg16(dev, KS_TXCR, w);

        w = RXCR1_RXFCE | RXCR1_RXBE | RXCR1_RXUE | RXCR1_RXME | RXCR1_RXIPFCC;

        /* Normal mode */
        w |= RXCR1_RXPAFMA;

        ks_wrreg16(dev, KS_RXCR1, w);
}

static void ks_setup_int(struct eth_device *dev)
{
        ks->rc_ier = 0x00;

        /* Clear the interrupts status of the hardware. */
        ks_wrreg16(dev, KS_ISR, 0xffff);

        /* Enables the interrupts of the hardware. */
        ks->rc_ier = (IRQ_LCI | IRQ_TXI | IRQ_RXI);
}

static int ks8851_mll_detect_chip(struct eth_device *dev)
{
        unsigned short val, i;

        ks_read_config(dev);

        val = ks_rdreg16(dev, KS_CIDER);

        if (val == 0xffff) {
                /* Special case -- no chip present */
                printf(DRIVERNAME ":  is chip mounted ?\n");
                return -1;
        } else if ((val & 0xfff0) != CIDER_ID) {
                printf(DRIVERNAME ": Invalid chip id 0x%04x\n", val);
                return -1;
        }

        debug("Read back KS8851 id 0x%x\n", val);

        /* only one entry in the table */
        val &= 0xfff0;
        for (i = 0; chip_ids[i].id != 0; i++) {
                if (chip_ids[i].id == val)
                        break;
        }
        if (!chip_ids[i].id) {
                printf(DRIVERNAME ": Unknown chip ID %04x\n", val);
                return -1;
        }

        dev->priv = (void *)&chip_ids[i];

        return 0;
}

static void ks8851_mll_reset(struct eth_device *dev)
{
        /* wake up powermode to normal mode */
        ks_set_powermode(dev, PMECR_PM_NORMAL);
        mdelay(1);      /* wait for normal mode to take effect */

        /* Disable interrupt and reset */
        ks_soft_reset(dev, GRR_GSR);

        /* turn off the IRQs and ack any outstanding */
        ks_wrreg16(dev, KS_IER, 0x0000);
        ks_wrreg16(dev, KS_ISR, 0xffff);

        /* shutdown RX/TX QMU */
        ks_disable_qmu(dev);
}

static void ks8851_mll_phy_configure(struct eth_device *dev)
{
        u16 data;

        ks_setup(dev);
        ks_setup_int(dev);

        /* Probing the phy */
        data = ks_rdreg16(dev, KS_OBCR);
        ks_wrreg16(dev, KS_OBCR, data | OBCR_ODS_16MA);

        debug(DRIVERNAME ": phy initialized\n");
}

static void ks8851_mll_enable(struct eth_device *dev)
{
        ks_wrreg16(dev, KS_ISR, 0xffff);
        ks_enable_int(dev);
        ks_enable_qmu(dev);
}

static int ks8851_mll_init(struct eth_device *dev, bd_t *bd)
{
        struct chip_id *id = dev->priv;

        debug(DRIVERNAME ": detected %s controller\n", id->name);

        if (ks_read_selftest(dev)) {
                printf(DRIVERNAME ": Selftest failed\n");
                return -1;
        }

        ks8851_mll_reset(dev);

        /* Configure the PHY, initialize the link state */
        ks8851_mll_phy_configure(dev);

        /* static allocation of private informations */
        ks->frame_head_info = fr_h_i;

        /* Turn on Tx + Rx */
        ks8851_mll_enable(dev);

        return 0;
}

static void ks_write_qmu(struct eth_device *dev, u8 *pdata, u16 len)
{
        /* start header at txb[0] to align txw entries */
        ks->txh.txw[0] = 0;
        ks->txh.txw[1] = cpu_to_le16(len);

        /* 1. set sudo-DMA mode */
        ks_wrreg16(dev, KS_TXFDPR, TXFDPR_TXFPAI);
        ks_wrreg8(dev, KS_RXQCR, (ks->rc_rxqcr | RXQCR_SDA) & 0xff);
        /* 2. write status/lenth info */
        ks_outblk(dev, ks->txh.txw, 4);
        /* 3. write pkt data */
        ks_outblk(dev, (u16 *)pdata, ALIGN(len, 4));
        /* 4. reset sudo-DMA mode */
        ks_wrreg8(dev, KS_RXQCR, (ks->rc_rxqcr & ~RXQCR_SDA) & 0xff);
        /* 5. Enqueue Tx(move the pkt from TX buffer into TXQ) */
        ks_wrreg16(dev, KS_TXQCR, TXQCR_METFE);
        /* 6. wait until TXQCR_METFE is auto-cleared */
        do { } while (ks_rdreg16(dev, KS_TXQCR) & TXQCR_METFE);
}

static int ks8851_mll_send(struct eth_device *dev, void *packet, int length)
{
        u8 *data = (u8 *)packet;
        u16 tmplen = (u16)length;
        u16 retv;

        /*
         * Extra space are required:
         * 4 byte for alignment, 4 for status/length, 4 for CRC
         */
        retv = ks_rdreg16(dev, KS_TXMIR) & 0x1fff;
        if (retv >= tmplen + 12) {
                ks_write_qmu(dev, data, tmplen);
                return 0;
        } else {
                printf(DRIVERNAME ": failed to send packet: No buffer\n");
                return -1;
        }
}

static void ks8851_mll_halt(struct eth_device *dev)
{
        ks8851_mll_reset(dev);
}

/*
 * Maximum receive ring size; that is, the number of packets
 * we can buffer before overflow happens. Basically, this just
 * needs to be enough to prevent a packet being discarded while
 * we are processing the previous one.
 */
static int ks8851_mll_recv(struct eth_device *dev)
{
        u16 status;

        status = ks_rdreg16(dev, KS_ISR);

        ks_wrreg16(dev, KS_ISR, status);

        if ((status & IRQ_RXI))
                ks_rcv(dev, (uchar **)net_rx_packets);

        if ((status & IRQ_LDI)) {
                u16 pmecr = ks_rdreg16(dev, KS_PMECR);
                pmecr &= ~PMECR_WKEVT_MASK;
                ks_wrreg16(dev, KS_PMECR, pmecr | PMECR_WKEVT_LINK);
        }

        return 0;
}

static int ks8851_mll_write_hwaddr(struct eth_device *dev)
{
        u16 addrl, addrm, addrh;

        addrh = (dev->enetaddr[0] << 8) | dev->enetaddr[1];
        addrm = (dev->enetaddr[2] << 8) | dev->enetaddr[3];
        addrl = (dev->enetaddr[4] << 8) | dev->enetaddr[5];

        ks_wrreg16(dev, KS_MARH, addrh);
        ks_wrreg16(dev, KS_MARM, addrm);
        ks_wrreg16(dev, KS_MARL, addrl);

        return 0;
}

int ks8851_mll_initialize(u8 dev_num, int base_addr)
{
        struct eth_device *dev;

        dev = malloc(sizeof(*dev));
        if (!dev) {
                printf("Error: Failed to allocate memory\n");
                return -1;
        }
        memset(dev, 0, sizeof(*dev));

        dev->iobase = base_addr;

        ks = &ks_str;

        /* Try to detect chip. Will fail if not present. */
        if (ks8851_mll_detect_chip(dev)) {
                free(dev);
                return -1;
        }

        dev->init = ks8851_mll_init;
        dev->halt = ks8851_mll_halt;
        dev->send = ks8851_mll_send;
        dev->recv = ks8851_mll_recv;
        dev->write_hwaddr = ks8851_mll_write_hwaddr;
        sprintf(dev->name, "%s-%hu", DRIVERNAME, dev_num);

        eth_register(dev);

        return 0;
}