nozomi.c

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/*
 * nozomi.c  -- HSDPA driver Broadband Wireless Data Card - Globe Trotter
 *
 * Written by: Ulf Jakobsson,
 *             Jan Åkerfeldt,
 *             Stefan Thomasson,
 *
 * Maintained by: Paul Hardwick ([email protected])
 *
 * Patches:
 *          Locking code changes for Vodafone by Sphere Systems Ltd,
 *                              Andrew Bird ([email protected] )
 *                              & Phil Sanderson
 *
 * Source has been ported from an implementation made by Filip Aben @ Option
 *
 * --------------------------------------------------------------------------
 *
 * Copyright (c) 2005,2006 Option Wireless Sweden AB
 * Copyright (c) 2006 Sphere Systems Ltd
 * Copyright (c) 2006 Option Wireless n/v
 * All rights Reserved.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * --------------------------------------------------------------------------
 */

/* Enable this to have a lot of debug printouts */
#define DEBUG

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/sched.h>
#include <linux/serial.h>
#include <linux/interrupt.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/kfifo.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <asm/byteorder.h>

#include <linux/delay.h>


#define VERSION_STRING DRIVER_DESC " 2.1d"

/*    Macros definitions */

/* Default debug printout level */
#define NOZOMI_DEBUG_LEVEL 0x00

#define P_BUF_SIZE 128
#define NFO(_err_flag_, args...)                \
do {                                \
    char tmp[P_BUF_SIZE];                   \
    snprintf(tmp, sizeof(tmp), ##args);         \
    printk(_err_flag_ "[%d] %s(): %s\n", __LINE__,      \
        __func__, tmp);             \
} while (0)

#define DBG1(args...) D_(0x01, ##args)
#define DBG2(args...) D_(0x02, ##args)
#define DBG3(args...) D_(0x04, ##args)
#define DBG4(args...) D_(0x08, ##args)
#define DBG5(args...) D_(0x10, ##args)
#define DBG6(args...) D_(0x20, ##args)
#define DBG7(args...) D_(0x40, ##args)
#define DBG8(args...) D_(0x80, ##args)

#ifdef DEBUG
/* Do we need this settable at runtime? */
static int debug = NOZOMI_DEBUG_LEVEL;

#define D(lvl, args...)  do \
            {if (lvl & debug) NFO(KERN_DEBUG, ##args); } \
            while (0)
#define D_(lvl, args...) D(lvl, ##args)

/* These printouts are always printed */

#else
static int debug;
#define D_(lvl, args...)
#endif

/* TODO: rewrite to optimize macros... */

#define TMP_BUF_MAX 256

#define DUMP(buf__,len__) \
  do {  \
    char tbuf[TMP_BUF_MAX] = {0};\
    if (len__ > 1) {\
    snprintf(tbuf, len__ > TMP_BUF_MAX ? TMP_BUF_MAX : len__, "%s", buf__);\
    if (tbuf[len__-2] == '\r') {\
        tbuf[len__-2] = 'r';\
    } \
    DBG1("SENDING: '%s' (%d+n)", tbuf, len__);\
    } else {\
    DBG1("SENDING: '%s' (%d)", tbuf, len__);\
    } \
} while (0)

/*    Defines */
#define NOZOMI_NAME     "nozomi"
#define NOZOMI_NAME_TTY     "nozomi_tty"
#define DRIVER_DESC     "Nozomi driver"

#define NTTY_TTY_MAXMINORS  256
#define NTTY_FIFO_BUFFER_SIZE   8192

/* Must be power of 2 */
#define FIFO_BUFFER_SIZE_UL 8192

/* Size of tmp send buffer to card */
#define SEND_BUF_MAX        1024
#define RECEIVE_BUF_MAX     4


#define R_IIR       0x0000  /* Interrupt Identity Register */
#define R_FCR       0x0000  /* Flow Control Register */
#define R_IER       0x0004  /* Interrupt Enable Register */

#define CONFIG_MAGIC    0xEFEFFEFE
#define TOGGLE_VALID    0x0000

/* Definition of interrupt tokens */
#define MDM_DL1     0x0001
#define MDM_UL1     0x0002
#define MDM_DL2     0x0004
#define MDM_UL2     0x0008
#define DIAG_DL1    0x0010
#define DIAG_DL2    0x0020
#define DIAG_UL     0x0040
#define APP1_DL     0x0080
#define APP1_UL     0x0100
#define APP2_DL     0x0200
#define APP2_UL     0x0400
#define CTRL_DL     0x0800
#define CTRL_UL     0x1000
#define RESET       0x8000

#define MDM_DL      (MDM_DL1  | MDM_DL2)
#define MDM_UL      (MDM_UL1  | MDM_UL2)
#define DIAG_DL     (DIAG_DL1 | DIAG_DL2)

/* modem signal definition */
#define CTRL_DSR    0x0001
#define CTRL_DCD    0x0002
#define CTRL_RI     0x0004
#define CTRL_CTS    0x0008

#define CTRL_DTR    0x0001
#define CTRL_RTS    0x0002

#define MAX_PORT        4
#define NOZOMI_MAX_PORTS    5
#define NOZOMI_MAX_CARDS    (NTTY_TTY_MAXMINORS / MAX_PORT)

/*    Type definitions */

/*
 * There are two types of nozomi cards,
 * one with 2048 memory and with 8192 memory
 */
enum card_type {
    F32_2 = 2048,   /* 512 bytes downlink + uplink * 2 -> 2048 */
    F32_8 = 8192,   /* 3072 bytes downl. + 1024 bytes uplink * 2 -> 8192 */
};

/* Initialization states a card can be in */
enum card_state {
    NOZOMI_STATE_UKNOWN = 0,
    NOZOMI_STATE_ENABLED    = 1,    /* pci device enabled */
    NOZOMI_STATE_ALLOCATED  = 2,    /* config setup done */
    NOZOMI_STATE_READY  = 3,    /* flowcontrols received */
};

/* Two different toggle channels exist */
enum channel_type {
    CH_A = 0,
    CH_B = 1,
};

/* Port definition for the card regarding flow control */
enum ctrl_port_type {
    CTRL_CMD    = 0,
    CTRL_MDM    = 1,
    CTRL_DIAG   = 2,
    CTRL_APP1   = 3,
    CTRL_APP2   = 4,
    CTRL_ERROR  = -1,
};

/* Ports that the nozomi has */
enum port_type {
    PORT_MDM    = 0,
    PORT_DIAG   = 1,
    PORT_APP1   = 2,
    PORT_APP2   = 3,
    PORT_CTRL   = 4,
    PORT_ERROR  = -1,
};

#ifdef __BIG_ENDIAN
/* Big endian */

struct toggles {
    unsigned int enabled:5; /*
                 * Toggle fields are valid if enabled is 0,
                 * else A-channels must always be used.
                 */
    unsigned int diag_dl:1;
    unsigned int mdm_dl:1;
    unsigned int mdm_ul:1;
} __attribute__ ((packed));

/* Configuration table to read at startup of card */
/* Is for now only needed during initialization phase */
struct config_table {
    u32 signature;
    u16 product_information;
    u16 version;
    u8 pad3[3];
    struct toggles toggle;
    u8 pad1[4];
    u16 dl_mdm_len1;    /*
                 * If this is 64, it can hold
                 * 60 bytes + 4 that is length field
                 */
    u16 dl_start;

    u16 dl_diag_len1;
    u16 dl_mdm_len2;    /*
                 * If this is 64, it can hold
                 * 60 bytes + 4 that is length field
                 */
    u16 dl_app1_len;

    u16 dl_diag_len2;
    u16 dl_ctrl_len;
    u16 dl_app2_len;
    u8 pad2[16];
    u16 ul_mdm_len1;
    u16 ul_start;
    u16 ul_diag_len;
    u16 ul_mdm_len2;
    u16 ul_app1_len;
    u16 ul_app2_len;
    u16 ul_ctrl_len;
} __attribute__ ((packed));

/* This stores all control downlink flags */
struct ctrl_dl {
    u8 port;
    unsigned int reserved:4;
    unsigned int CTS:1;
    unsigned int RI:1;
    unsigned int DCD:1;
    unsigned int DSR:1;
} __attribute__ ((packed));

/* This stores all control uplink flags */
struct ctrl_ul {
    u8 port;
    unsigned int reserved:6;
    unsigned int RTS:1;
    unsigned int DTR:1;
} __attribute__ ((packed));

#else
/* Little endian */

/* This represents the toggle information */
struct toggles {
    unsigned int mdm_ul:1;
    unsigned int mdm_dl:1;
    unsigned int diag_dl:1;
    unsigned int enabled:5; /*
                 * Toggle fields are valid if enabled is 0,
                 * else A-channels must always be used.
                 */
} __attribute__ ((packed));

/* Configuration table to read at startup of card */
struct config_table {
    u32 signature;
    u16 version;
    u16 product_information;
    struct toggles toggle;
    u8 pad1[7];
    u16 dl_start;
    u16 dl_mdm_len1;    /*
                 * If this is 64, it can hold
                 * 60 bytes + 4 that is length field
                 */
    u16 dl_mdm_len2;
    u16 dl_diag_len1;
    u16 dl_diag_len2;
    u16 dl_app1_len;
    u16 dl_app2_len;
    u16 dl_ctrl_len;
    u8 pad2[16];
    u16 ul_start;
    u16 ul_mdm_len2;
    u16 ul_mdm_len1;
    u16 ul_diag_len;
    u16 ul_app1_len;
    u16 ul_app2_len;
    u16 ul_ctrl_len;
} __attribute__ ((packed));

/* This stores all control downlink flags */
struct ctrl_dl {
    unsigned int DSR:1;
    unsigned int DCD:1;
    unsigned int RI:1;
    unsigned int CTS:1;
    unsigned int reserverd:4;
    u8 port;
} __attribute__ ((packed));

/* This stores all control uplink flags */
struct ctrl_ul {
    unsigned int DTR:1;
    unsigned int RTS:1;
    unsigned int reserved:6;
    u8 port;
} __attribute__ ((packed));
#endif

/* This holds all information that is needed regarding a port */
struct port {
    struct tty_port port;
    u8 update_flow_control;
    struct ctrl_ul ctrl_ul;
    struct ctrl_dl ctrl_dl;
    struct kfifo fifo_ul;
    void __iomem *dl_addr[2];
    u32 dl_size[2];
    u8 toggle_dl;
    void __iomem *ul_addr[2];
    u32 ul_size[2];
    u8 toggle_ul;
    u16 token_dl;

    wait_queue_head_t tty_wait;
    struct async_icount tty_icount;

    struct nozomi *dc;
};

/* Private data one for each card in the system */
struct nozomi {
    void __iomem *base_addr;
    unsigned long flip;

    /* Pointers to registers */
    void __iomem *reg_iir;
    void __iomem *reg_fcr;
    void __iomem *reg_ier;

    u16 last_ier;
    enum card_type card_type;
    struct config_table config_table;   /* Configuration table */
    struct pci_dev *pdev;
    struct port port[NOZOMI_MAX_PORTS];
    u8 *send_buf;

    spinlock_t spin_mutex;  /* secures access to registers and tty */

    unsigned int index_start;
    enum card_state state;
    u32 open_ttys;
};

/* This is a data packet that is read or written to/from card */
struct buffer {
    u32 size;       /* size is the length of the data buffer */
    u8 *data;
} __attribute__ ((packed));

/*    Global variables */
static const struct pci_device_id nozomi_pci_tbl[] __devinitconst = {
    {PCI_DEVICE(0x1931, 0x000c)},   /* Nozomi HSDPA */
    {},
};

MODULE_DEVICE_TABLE(pci, nozomi_pci_tbl);

static struct nozomi *ndevs[NOZOMI_MAX_CARDS];
static struct tty_driver *ntty_driver;

static const struct tty_port_operations noz_tty_port_ops;

/*
 * find card by tty_index
 */
static inline struct nozomi *get_dc_by_tty(const struct tty_struct *tty)
{
    return tty ? ndevs[tty->index / MAX_PORT] : NULL;
}

static inline struct port *get_port_by_tty(const struct tty_struct *tty)
{
    struct nozomi *ndev = get_dc_by_tty(tty);
    return ndev ? &ndev->port[tty->index % MAX_PORT] : NULL;
}

/*
 * TODO:
 * -Optimize
 * -Rewrite cleaner
 */

static void read_mem32(u32 *buf, const void __iomem *mem_addr_start,
            u32 size_bytes)
{
    u32 i = 0;
    const u32 __iomem *ptr = mem_addr_start;
    u16 *buf16;

    if (unlikely(!ptr || !buf))
        goto out;

    /* shortcut for extremely often used cases */
    switch (size_bytes) {
    case 2: /* 2 bytes */
        buf16 = (u16 *) buf;
        *buf16 = __le16_to_cpu(readw(ptr));
        goto out;
        break;
    case 4: /* 4 bytes */
        *(buf) = __le32_to_cpu(readl(ptr));
        goto out;
        break;
    }

    while (i < size_bytes) {
        if (size_bytes - i == 2) {
            /* Handle 2 bytes in the end */
            buf16 = (u16 *) buf;
            *(buf16) = __le16_to_cpu(readw(ptr));
            i += 2;
        } else {
            /* Read 4 bytes */
            *(buf) = __le32_to_cpu(readl(ptr));
            i += 4;
        }
        buf++;
        ptr++;
    }
out:
    return;
}

/*
 * TODO:
 * -Optimize
 * -Rewrite cleaner
 */
static u32 write_mem32(void __iomem *mem_addr_start, const u32 *buf,
            u32 size_bytes)
{
    u32 i = 0;
    u32 __iomem *ptr = mem_addr_start;
    const u16 *buf16;

    if (unlikely(!ptr || !buf))
        return 0;

    /* shortcut for extremely often used cases */
    switch (size_bytes) {
    case 2: /* 2 bytes */
        buf16 = (const u16 *)buf;
        writew(__cpu_to_le16(*buf16), ptr);
        return 2;
        break;
    case 1: /*
         * also needs to write 4 bytes in this case
         * so falling through..
         */
    case 4: /* 4 bytes */
        writel(__cpu_to_le32(*buf), ptr);
        return 4;
        break;
    }

    while (i < size_bytes) {
        if (size_bytes - i == 2) {
            /* 2 bytes */
            buf16 = (const u16 *)buf;
            writew(__cpu_to_le16(*buf16), ptr);
            i += 2;
        } else {
            /* 4 bytes */
            writel(__cpu_to_le32(*buf), ptr);
            i += 4;
        }
        buf++;
        ptr++;
    }
    return i;
}

/* Setup pointers to different channels and also setup buffer sizes. */
static void setup_memory(struct nozomi *dc)
{
    void __iomem *offset = dc->base_addr + dc->config_table.dl_start;
    /* The length reported is including the length field of 4 bytes,
     * hence subtract with 4.
     */
    const u16 buff_offset = 4;

    /* Modem port dl configuration */
    dc->port[PORT_MDM].dl_addr[CH_A] = offset;
    dc->port[PORT_MDM].dl_addr[CH_B] =
                (offset += dc->config_table.dl_mdm_len1);
    dc->port[PORT_MDM].dl_size[CH_A] =
                dc->config_table.dl_mdm_len1 - buff_offset;
    dc->port[PORT_MDM].dl_size[CH_B] =
                dc->config_table.dl_mdm_len2 - buff_offset;

    /* Diag port dl configuration */
    dc->port[PORT_DIAG].dl_addr[CH_A] =
                (offset += dc->config_table.dl_mdm_len2);
    dc->port[PORT_DIAG].dl_size[CH_A] =
                dc->config_table.dl_diag_len1 - buff_offset;
    dc->port[PORT_DIAG].dl_addr[CH_B] =
                (offset += dc->config_table.dl_diag_len1);
    dc->port[PORT_DIAG].dl_size[CH_B] =
                dc->config_table.dl_diag_len2 - buff_offset;

    /* App1 port dl configuration */
    dc->port[PORT_APP1].dl_addr[CH_A] =
                (offset += dc->config_table.dl_diag_len2);
    dc->port[PORT_APP1].dl_size[CH_A] =
                dc->config_table.dl_app1_len - buff_offset;

    /* App2 port dl configuration */
    dc->port[PORT_APP2].dl_addr[CH_A] =
                (offset += dc->config_table.dl_app1_len);
    dc->port[PORT_APP2].dl_size[CH_A] =
                dc->config_table.dl_app2_len - buff_offset;

    /* Ctrl dl configuration */
    dc->port[PORT_CTRL].dl_addr[CH_A] =
                (offset += dc->config_table.dl_app2_len);
    dc->port[PORT_CTRL].dl_size[CH_A] =
                dc->config_table.dl_ctrl_len - buff_offset;

    offset = dc->base_addr + dc->config_table.ul_start;

    /* Modem Port ul configuration */
    dc->port[PORT_MDM].ul_addr[CH_A] = offset;
    dc->port[PORT_MDM].ul_size[CH_A] =
                dc->config_table.ul_mdm_len1 - buff_offset;
    dc->port[PORT_MDM].ul_addr[CH_B] =
                (offset += dc->config_table.ul_mdm_len1);
    dc->port[PORT_MDM].ul_size[CH_B] =
                dc->config_table.ul_mdm_len2 - buff_offset;

    /* Diag port ul configuration */
    dc->port[PORT_DIAG].ul_addr[CH_A] =
                (offset += dc->config_table.ul_mdm_len2);
    dc->port[PORT_DIAG].ul_size[CH_A] =
                dc->config_table.ul_diag_len - buff_offset;

    /* App1 port ul configuration */
    dc->port[PORT_APP1].ul_addr[CH_A] =
                (offset += dc->config_table.ul_diag_len);
    dc->port[PORT_APP1].ul_size[CH_A] =
                dc->config_table.ul_app1_len - buff_offset;

    /* App2 port ul configuration */
    dc->port[PORT_APP2].ul_addr[CH_A] =
                (offset += dc->config_table.ul_app1_len);
    dc->port[PORT_APP2].ul_size[CH_A] =
                dc->config_table.ul_app2_len - buff_offset;

    /* Ctrl ul configuration */
    dc->port[PORT_CTRL].ul_addr[CH_A] =
                (offset += dc->config_table.ul_app2_len);
    dc->port[PORT_CTRL].ul_size[CH_A] =
                dc->config_table.ul_ctrl_len - buff_offset;
}

/* Dump config table under initalization phase */
#ifdef DEBUG
static void dump_table(const struct nozomi *dc)
{
    DBG3("signature: 0x%08X", dc->config_table.signature);
    DBG3("version: 0x%04X", dc->config_table.version);
    DBG3("product_information: 0x%04X", \
                dc->config_table.product_information);
    DBG3("toggle enabled: %d", dc->config_table.toggle.enabled);
    DBG3("toggle up_mdm: %d", dc->config_table.toggle.mdm_ul);
    DBG3("toggle dl_mdm: %d", dc->config_table.toggle.mdm_dl);
    DBG3("toggle dl_dbg: %d", dc->config_table.toggle.diag_dl);

    DBG3("dl_start: 0x%04X", dc->config_table.dl_start);
    DBG3("dl_mdm_len0: 0x%04X, %d", dc->config_table.dl_mdm_len1,
       dc->config_table.dl_mdm_len1);
    DBG3("dl_mdm_len1: 0x%04X, %d", dc->config_table.dl_mdm_len2,
       dc->config_table.dl_mdm_len2);
    DBG3("dl_diag_len0: 0x%04X, %d", dc->config_table.dl_diag_len1,
       dc->config_table.dl_diag_len1);
    DBG3("dl_diag_len1: 0x%04X, %d", dc->config_table.dl_diag_len2,
       dc->config_table.dl_diag_len2);
    DBG3("dl_app1_len: 0x%04X, %d", dc->config_table.dl_app1_len,
       dc->config_table.dl_app1_len);
    DBG3("dl_app2_len: 0x%04X, %d", dc->config_table.dl_app2_len,
       dc->config_table.dl_app2_len);
    DBG3("dl_ctrl_len: 0x%04X, %d", dc->config_table.dl_ctrl_len,
       dc->config_table.dl_ctrl_len);
    DBG3("ul_start: 0x%04X, %d", dc->config_table.ul_start,
       dc->config_table.ul_start);
    DBG3("ul_mdm_len[0]: 0x%04X, %d", dc->config_table.ul_mdm_len1,
       dc->config_table.ul_mdm_len1);
    DBG3("ul_mdm_len[1]: 0x%04X, %d", dc->config_table.ul_mdm_len2,
       dc->config_table.ul_mdm_len2);
    DBG3("ul_diag_len: 0x%04X, %d", dc->config_table.ul_diag_len,
       dc->config_table.ul_diag_len);
    DBG3("ul_app1_len: 0x%04X, %d", dc->config_table.ul_app1_len,
       dc->config_table.ul_app1_len);
    DBG3("ul_app2_len: 0x%04X, %d", dc->config_table.ul_app2_len,
       dc->config_table.ul_app2_len);
    DBG3("ul_ctrl_len: 0x%04X, %d", dc->config_table.ul_ctrl_len,
       dc->config_table.ul_ctrl_len);
}
#else
static inline void dump_table(const struct nozomi *dc) { }
#endif

/*
 * Read configuration table from card under intalization phase
 * Returns 1 if ok, else 0
 */
static int nozomi_read_config_table(struct nozomi *dc)
{
    read_mem32((u32 *) &dc->config_table, dc->base_addr + 0,
                        sizeof(struct config_table));

    if (dc->config_table.signature != CONFIG_MAGIC) {
        dev_err(&dc->pdev->dev, "ConfigTable Bad! 0x%08X != 0x%08X\n",
            dc->config_table.signature, CONFIG_MAGIC);
        return 0;
    }

    if ((dc->config_table.version == 0)
        || (dc->config_table.toggle.enabled == TOGGLE_VALID)) {
        int i;
        DBG1("Second phase, configuring card");

        setup_memory(dc);

        dc->port[PORT_MDM].toggle_ul = dc->config_table.toggle.mdm_ul;
        dc->port[PORT_MDM].toggle_dl = dc->config_table.toggle.mdm_dl;
        dc->port[PORT_DIAG].toggle_dl = dc->config_table.toggle.diag_dl;
        DBG1("toggle ports: MDM UL:%d MDM DL:%d, DIAG DL:%d",
           dc->port[PORT_MDM].toggle_ul,
           dc->port[PORT_MDM].toggle_dl, dc->port[PORT_DIAG].toggle_dl);

        dump_table(dc);

        for (i = PORT_MDM; i < MAX_PORT; i++) {
            memset(&dc->port[i].ctrl_dl, 0, sizeof(struct ctrl_dl));
            memset(&dc->port[i].ctrl_ul, 0, sizeof(struct ctrl_ul));
        }

        /* Enable control channel */
        dc->last_ier = dc->last_ier | CTRL_DL;
        writew(dc->last_ier, dc->reg_ier);

        dc->state = NOZOMI_STATE_ALLOCATED;
        dev_info(&dc->pdev->dev, "Initialization OK!\n");
        return 1;
    }

    if ((dc->config_table.version > 0)
        && (dc->config_table.toggle.enabled != TOGGLE_VALID)) {
        u32 offset = 0;
        DBG1("First phase: pushing upload buffers, clearing download");

        dev_info(&dc->pdev->dev, "Version of card: %d\n",
             dc->config_table.version);

        /* Here we should disable all I/O over F32. */
        setup_memory(dc);

        /*
         * We should send ALL channel pair tokens back along
         * with reset token
         */

        /* push upload modem buffers */
        write_mem32(dc->port[PORT_MDM].ul_addr[CH_A],
            (u32 *) &offset, 4);
        write_mem32(dc->port[PORT_MDM].ul_addr[CH_B],
            (u32 *) &offset, 4);

        writew(MDM_UL | DIAG_DL | MDM_DL, dc->reg_fcr);

        DBG1("First phase done");
    }

    return 1;
}

/* Enable uplink interrupts  */
static void enable_transmit_ul(enum port_type port, struct nozomi *dc)
{
    static const u16 mask[] = {MDM_UL, DIAG_UL, APP1_UL, APP2_UL, CTRL_UL};

    if (port < NOZOMI_MAX_PORTS) {
        dc->last_ier |= mask[port];
        writew(dc->last_ier, dc->reg_ier);
    } else {
        dev_err(&dc->pdev->dev, "Called with wrong port?\n");
    }
}

/* Disable uplink interrupts  */
static void disable_transmit_ul(enum port_type port, struct nozomi *dc)
{
    static const u16 mask[] =
        {~MDM_UL, ~DIAG_UL, ~APP1_UL, ~APP2_UL, ~CTRL_UL};

    if (port < NOZOMI_MAX_PORTS) {
        dc->last_ier &= mask[port];
        writew(dc->last_ier, dc->reg_ier);
    } else {
        dev_err(&dc->pdev->dev, "Called with wrong port?\n");
    }
}

/* Enable downlink interrupts */
static void enable_transmit_dl(enum port_type port, struct nozomi *dc)
{
    static const u16 mask[] = {MDM_DL, DIAG_DL, APP1_DL, APP2_DL, CTRL_DL};

    if (port < NOZOMI_MAX_PORTS) {
        dc->last_ier |= mask[port];
        writew(dc->last_ier, dc->reg_ier);
    } else {
        dev_err(&dc->pdev->dev, "Called with wrong port?\n");
    }
}

/* Disable downlink interrupts */
static void disable_transmit_dl(enum port_type port, struct nozomi *dc)
{
    static const u16 mask[] =
        {~MDM_DL, ~DIAG_DL, ~APP1_DL, ~APP2_DL, ~CTRL_DL};

    if (port < NOZOMI_MAX_PORTS) {
        dc->last_ier &= mask[port];
        writew(dc->last_ier, dc->reg_ier);
    } else {
        dev_err(&dc->pdev->dev, "Called with wrong port?\n");
    }
}

/*
 * Return 1 - send buffer to card and ack.
 * Return 0 - don't ack, don't send buffer to card.
 */
static int send_data(enum port_type index, struct nozomi *dc)
{
    u32 size = 0;
    struct port *port = &dc->port[index];
    const u8 toggle = port->toggle_ul;
    void __iomem *addr = port->ul_addr[toggle];
    const u32 ul_size = port->ul_size[toggle];
    struct tty_struct *tty = tty_port_tty_get(&port->port);

    /* Get data from tty and place in buf for now */
    size = kfifo_out(&port->fifo_ul, dc->send_buf,
               ul_size < SEND_BUF_MAX ? ul_size : SEND_BUF_MAX);

    if (size == 0) {
        DBG4("No more data to send, disable link:");
        tty_kref_put(tty);
        return 0;
    }

    /* DUMP(buf, size); */

    /* Write length + data */
    write_mem32(addr, (u32 *) &size, 4);
    write_mem32(addr + 4, (u32 *) dc->send_buf, size);

    if (tty)
        tty_wakeup(tty);

    tty_kref_put(tty);
    return 1;
}

/* If all data has been read, return 1, else 0 */
static int receive_data(enum port_type index, struct nozomi *dc)
{
    u8 buf[RECEIVE_BUF_MAX] = { 0 };
    int size;
    u32 offset = 4;
    struct port *port = &dc->port[index];
    void __iomem *addr = port->dl_addr[port->toggle_dl];
    struct tty_struct *tty = tty_port_tty_get(&port->port);
    int i, ret;

    if (unlikely(!tty)) {
        DBG1("tty not open for port: %d?", index);
        return 1;
    }

    read_mem32((u32 *) &size, addr, 4);
    /*  DBG1( "%d bytes port: %d", size, index); */

    if (test_bit(TTY_THROTTLED, &tty->flags)) {
        DBG1("No room in tty, don't read data, don't ack interrupt, "
            "disable interrupt");

        /* disable interrupt in downlink... */
        disable_transmit_dl(index, dc);
        ret = 0;
        goto put;
    }

    if (unlikely(size == 0)) {
        dev_err(&dc->pdev->dev, "size == 0?\n");
        ret = 1;
        goto put;
    }

    while (size > 0) {
        read_mem32((u32 *) buf, addr + offset, RECEIVE_BUF_MAX);

        if (size == 1) {
            tty_insert_flip_char(tty, buf[0], TTY_NORMAL);
            size = 0;
        } else if (size < RECEIVE_BUF_MAX) {
            size -= tty_insert_flip_string(tty, (char *) buf, size);
        } else {
            i = tty_insert_flip_string(tty, \
                        (char *) buf, RECEIVE_BUF_MAX);
            size -= i;
            offset += i;
        }
    }

    set_bit(index, &dc->flip);
    ret = 1;
put:
    tty_kref_put(tty);
    return ret;
}

/* Debug for interrupts */
#ifdef DEBUG
static char *interrupt2str(u16 interrupt)
{
    static char buf[TMP_BUF_MAX];
    char *p = buf;

    interrupt & MDM_DL1 ? p += snprintf(p, TMP_BUF_MAX, "MDM_DL1 ") : NULL;
    interrupt & MDM_DL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "MDM_DL2 ") : NULL;

    interrupt & MDM_UL1 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "MDM_UL1 ") : NULL;
    interrupt & MDM_UL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "MDM_UL2 ") : NULL;

    interrupt & DIAG_DL1 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "DIAG_DL1 ") : NULL;
    interrupt & DIAG_DL2 ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "DIAG_DL2 ") : NULL;

    interrupt & DIAG_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "DIAG_UL ") : NULL;

    interrupt & APP1_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "APP1_DL ") : NULL;
    interrupt & APP2_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "APP2_DL ") : NULL;

    interrupt & APP1_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "APP1_UL ") : NULL;
    interrupt & APP2_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "APP2_UL ") : NULL;

    interrupt & CTRL_DL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "CTRL_DL ") : NULL;
    interrupt & CTRL_UL ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "CTRL_UL ") : NULL;

    interrupt & RESET ? p += snprintf(p, TMP_BUF_MAX - (p - buf),
                    "RESET ") : NULL;

    return buf;
}
#endif

/*
 * Receive flow control
 * Return 1 - If ok, else 0
 */
static int receive_flow_control(struct nozomi *dc)
{
    enum port_type port = PORT_MDM;
    struct ctrl_dl ctrl_dl;
    struct ctrl_dl old_ctrl;
    u16 enable_ier = 0;

    read_mem32((u32 *) &ctrl_dl, dc->port[PORT_CTRL].dl_addr[CH_A], 2);

    switch (ctrl_dl.port) {
    case CTRL_CMD:
        DBG1("The Base Band sends this value as a response to a "
            "request for IMSI detach sent over the control "
            "channel uplink (see section 7.6.1).");
        break;
    case CTRL_MDM:
        port = PORT_MDM;
        enable_ier = MDM_DL;
        break;
    case CTRL_DIAG:
        port = PORT_DIAG;
        enable_ier = DIAG_DL;
        break;
    case CTRL_APP1:
        port = PORT_APP1;
        enable_ier = APP1_DL;
        break;
    case CTRL_APP2:
        port = PORT_APP2;
        enable_ier = APP2_DL;
        if (dc->state == NOZOMI_STATE_ALLOCATED) {
            /*
             * After card initialization the flow control
             * received for APP2 is always the last
             */
            dc->state = NOZOMI_STATE_READY;
            dev_info(&dc->pdev->dev, "Device READY!\n");
        }
        break;
    default:
        dev_err(&dc->pdev->dev,
            "ERROR: flow control received for non-existing port\n");
        return 0;
    };

    DBG1("0x%04X->0x%04X", *((u16 *)&dc->port[port].ctrl_dl),
       *((u16 *)&ctrl_dl));

    old_ctrl = dc->port[port].ctrl_dl;
    dc->port[port].ctrl_dl = ctrl_dl;

    if (old_ctrl.CTS == 1 && ctrl_dl.CTS == 0) {
        DBG1("Disable interrupt (0x%04X) on port: %d",
            enable_ier, port);
        disable_transmit_ul(port, dc);

    } else if (old_ctrl.CTS == 0 && ctrl_dl.CTS == 1) {

        if (kfifo_len(&dc->port[port].fifo_ul)) {
            DBG1("Enable interrupt (0x%04X) on port: %d",
                enable_ier, port);
            DBG1("Data in buffer [%d], enable transmit! ",
                kfifo_len(&dc->port[port].fifo_ul));
            enable_transmit_ul(port, dc);
        } else {
            DBG1("No data in buffer...");
        }
    }

    if (*(u16 *)&old_ctrl == *(u16 *)&ctrl_dl) {
        DBG1(" No change in mctrl");
        return 1;
    }
    /* Update statistics */
    if (old_ctrl.CTS != ctrl_dl.CTS)
        dc->port[port].tty_icount.cts++;
    if (old_ctrl.DSR != ctrl_dl.DSR)
        dc->port[port].tty_icount.dsr++;
    if (old_ctrl.RI != ctrl_dl.RI)
        dc->port[port].tty_icount.rng++;
    if (old_ctrl.DCD != ctrl_dl.DCD)
        dc->port[port].tty_icount.dcd++;

    wake_up_interruptible(&dc->port[port].tty_wait);

    DBG1("port: %d DCD(%d), CTS(%d), RI(%d), DSR(%d)",
       port,
       dc->port[port].tty_icount.dcd, dc->port[port].tty_icount.cts,
       dc->port[port].tty_icount.rng, dc->port[port].tty_icount.dsr);

    return 1;
}

static enum ctrl_port_type port2ctrl(enum port_type port,
                    const struct nozomi *dc)
{
    switch (port) {
    case PORT_MDM:
        return CTRL_MDM;
    case PORT_DIAG:
        return CTRL_DIAG;
    case PORT_APP1:
        return CTRL_APP1;
    case PORT_APP2:
        return CTRL_APP2;
    default:
        dev_err(&dc->pdev->dev,
            "ERROR: send flow control " \
            "received for non-existing port\n");
    };
    return CTRL_ERROR;
}

/*
 * Send flow control, can only update one channel at a time
 * Return 0 - If we have updated all flow control
 * Return 1 - If we need to update more flow control, ack current enable more
 */
static int send_flow_control(struct nozomi *dc)
{
    u32 i, more_flow_control_to_be_updated = 0;
    u16 *ctrl;

    for (i = PORT_MDM; i < MAX_PORT; i++) {
        if (dc->port[i].update_flow_control) {
            if (more_flow_control_to_be_updated) {
                /* We have more flow control to be updated */
                return 1;
            }
            dc->port[i].ctrl_ul.port = port2ctrl(i, dc);
            ctrl = (u16 *)&dc->port[i].ctrl_ul;
            write_mem32(dc->port[PORT_CTRL].ul_addr[0], \
                (u32 *) ctrl, 2);
            dc->port[i].update_flow_control = 0;
            more_flow_control_to_be_updated = 1;
        }
    }
    return 0;
}

/*
 * Handle downlink data, ports that are handled are modem and diagnostics
 * Return 1 - ok
 * Return 0 - toggle fields are out of sync
 */
static int handle_data_dl(struct nozomi *dc, enum port_type port, u8 *toggle,
            u16 read_iir, u16 mask1, u16 mask2)
{
    if (*toggle == 0 && read_iir & mask1) {
        if (receive_data(port, dc)) {
            writew(mask1, dc->reg_fcr);
            *toggle = !(*toggle);
        }

        if (read_iir & mask2) {
            if (receive_data(port, dc)) {
                writew(mask2, dc->reg_fcr);
                *toggle = !(*toggle);
            }
        }
    } else if (*toggle == 1 && read_iir & mask2) {
        if (receive_data(port, dc)) {
            writew(mask2, dc->reg_fcr);
            *toggle = !(*toggle);
        }

        if (read_iir & mask1) {
            if (receive_data(port, dc)) {
                writew(mask1, dc->reg_fcr);
                *toggle = !(*toggle);
            }
        }
    } else {
        dev_err(&dc->pdev->dev, "port out of sync!, toggle:%d\n",
            *toggle);
        return 0;
    }
    return 1;
}

/*
 * Handle uplink data, this is currently for the modem port
 * Return 1 - ok
 * Return 0 - toggle field are out of sync
 */
static int handle_data_ul(struct nozomi *dc, enum port_type port, u16 read_iir)
{
    u8 *toggle = &(dc->port[port].toggle_ul);

    if (*toggle == 0 && read_iir & MDM_UL1) {
        dc->last_ier &= ~MDM_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_data(port, dc)) {
            writew(MDM_UL1, dc->reg_fcr);
            dc->last_ier = dc->last_ier | MDM_UL;
            writew(dc->last_ier, dc->reg_ier);
            *toggle = !*toggle;
        }

        if (read_iir & MDM_UL2) {
            dc->last_ier &= ~MDM_UL;
            writew(dc->last_ier, dc->reg_ier);
            if (send_data(port, dc)) {
                writew(MDM_UL2, dc->reg_fcr);
                dc->last_ier = dc->last_ier | MDM_UL;
                writew(dc->last_ier, dc->reg_ier);
                *toggle = !*toggle;
            }
        }

    } else if (*toggle == 1 && read_iir & MDM_UL2) {
        dc->last_ier &= ~MDM_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_data(port, dc)) {
            writew(MDM_UL2, dc->reg_fcr);
            dc->last_ier = dc->last_ier | MDM_UL;
            writew(dc->last_ier, dc->reg_ier);
            *toggle = !*toggle;
        }

        if (read_iir & MDM_UL1) {
            dc->last_ier &= ~MDM_UL;
            writew(dc->last_ier, dc->reg_ier);
            if (send_data(port, dc)) {
                writew(MDM_UL1, dc->reg_fcr);
                dc->last_ier = dc->last_ier | MDM_UL;
                writew(dc->last_ier, dc->reg_ier);
                *toggle = !*toggle;
            }
        }
    } else {
        writew(read_iir & MDM_UL, dc->reg_fcr);
        dev_err(&dc->pdev->dev, "port out of sync!\n");
        return 0;
    }
    return 1;
}

static irqreturn_t interrupt_handler(int irq, void *dev_id)
{
    struct nozomi *dc = dev_id;
    unsigned int a;
    u16 read_iir;

    if (!dc)
        return IRQ_NONE;

    spin_lock(&dc->spin_mutex);
    read_iir = readw(dc->reg_iir);

    /* Card removed */
    if (read_iir == (u16)-1)
        goto none;
    /*
     * Just handle interrupt enabled in IER
     * (by masking with dc->last_ier)
     */
    read_iir &= dc->last_ier;

    if (read_iir == 0)
        goto none;


    DBG4("%s irq:0x%04X, prev:0x%04X", interrupt2str(read_iir), read_iir,
        dc->last_ier);

    if (read_iir & RESET) {
        if (unlikely(!nozomi_read_config_table(dc))) {
            dc->last_ier = 0x0;
            writew(dc->last_ier, dc->reg_ier);
            dev_err(&dc->pdev->dev, "Could not read status from "
                "card, we should disable interface\n");
        } else {
            writew(RESET, dc->reg_fcr);
        }
        /* No more useful info if this was the reset interrupt. */
        goto exit_handler;
    }
    if (read_iir & CTRL_UL) {
        DBG1("CTRL_UL");
        dc->last_ier &= ~CTRL_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_flow_control(dc)) {
            writew(CTRL_UL, dc->reg_fcr);
            dc->last_ier = dc->last_ier | CTRL_UL;
            writew(dc->last_ier, dc->reg_ier);
        }
    }
    if (read_iir & CTRL_DL) {
        receive_flow_control(dc);
        writew(CTRL_DL, dc->reg_fcr);
    }
    if (read_iir & MDM_DL) {
        if (!handle_data_dl(dc, PORT_MDM,
                &(dc->port[PORT_MDM].toggle_dl), read_iir,
                MDM_DL1, MDM_DL2)) {
            dev_err(&dc->pdev->dev, "MDM_DL out of sync!\n");
            goto exit_handler;
        }
    }
    if (read_iir & MDM_UL) {
        if (!handle_data_ul(dc, PORT_MDM, read_iir)) {
            dev_err(&dc->pdev->dev, "MDM_UL out of sync!\n");
            goto exit_handler;
        }
    }
    if (read_iir & DIAG_DL) {
        if (!handle_data_dl(dc, PORT_DIAG,
                &(dc->port[PORT_DIAG].toggle_dl), read_iir,
                DIAG_DL1, DIAG_DL2)) {
            dev_err(&dc->pdev->dev, "DIAG_DL out of sync!\n");
            goto exit_handler;
        }
    }
    if (read_iir & DIAG_UL) {
        dc->last_ier &= ~DIAG_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_data(PORT_DIAG, dc)) {
            writew(DIAG_UL, dc->reg_fcr);
            dc->last_ier = dc->last_ier | DIAG_UL;
            writew(dc->last_ier, dc->reg_ier);
        }
    }
    if (read_iir & APP1_DL) {
        if (receive_data(PORT_APP1, dc))
            writew(APP1_DL, dc->reg_fcr);
    }
    if (read_iir & APP1_UL) {
        dc->last_ier &= ~APP1_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_data(PORT_APP1, dc)) {
            writew(APP1_UL, dc->reg_fcr);
            dc->last_ier = dc->last_ier | APP1_UL;
            writew(dc->last_ier, dc->reg_ier);
        }
    }
    if (read_iir & APP2_DL) {
        if (receive_data(PORT_APP2, dc))
            writew(APP2_DL, dc->reg_fcr);
    }
    if (read_iir & APP2_UL) {
        dc->last_ier &= ~APP2_UL;
        writew(dc->last_ier, dc->reg_ier);
        if (send_data(PORT_APP2, dc)) {
            writew(APP2_UL, dc->reg_fcr);
            dc->last_ier = dc->last_ier | APP2_UL;
            writew(dc->last_ier, dc->reg_ier);
        }
    }

exit_handler:
    spin_unlock(&dc->spin_mutex);
    for (a = 0; a < NOZOMI_MAX_PORTS; a++) {
        struct tty_struct *tty;
        if (test_and_clear_bit(a, &dc->flip)) {
            tty = tty_port_tty_get(&dc->port[a].port);
            if (tty)
                tty_flip_buffer_push(tty);
            tty_kref_put(tty);
        }
    }
    return IRQ_HANDLED;
none:
    spin_unlock(&dc->spin_mutex);
    return IRQ_NONE;
}

static void nozomi_get_card_type(struct nozomi *dc)
{
    int i;
    u32 size = 0;

    for (i = 0; i < 6; i++)
        size += pci_resource_len(dc->pdev, i);

    /* Assume card type F32_8 if no match */
    dc->card_type = size == 2048 ? F32_2 : F32_8;

    dev_info(&dc->pdev->dev, "Card type is: %d\n", dc->card_type);
}

static void nozomi_setup_private_data(struct nozomi *dc)
{
    void __iomem *offset = dc->base_addr + dc->card_type / 2;
    unsigned int i;

    dc->reg_fcr = (void __iomem *)(offset + R_FCR);
    dc->reg_iir = (void __iomem *)(offset + R_IIR);
    dc->reg_ier = (void __iomem *)(offset + R_IER);
    dc->last_ier = 0;
    dc->flip = 0;

    dc->port[PORT_MDM].token_dl = MDM_DL;
    dc->port[PORT_DIAG].token_dl = DIAG_DL;
    dc->port[PORT_APP1].token_dl = APP1_DL;
    dc->port[PORT_APP2].token_dl = APP2_DL;

    for (i = 0; i < MAX_PORT; i++)
        init_waitqueue_head(&dc->port[i].tty_wait);
}

static ssize_t card_type_show(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    const struct nozomi *dc = pci_get_drvdata(to_pci_dev(dev));

    return sprintf(buf, "%d\n", dc->card_type);
}
static DEVICE_ATTR(card_type, S_IRUGO, card_type_show, NULL);

static ssize_t open_ttys_show(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    const struct nozomi *dc = pci_get_drvdata(to_pci_dev(dev));

    return sprintf(buf, "%u\n", dc->open_ttys);
}
static DEVICE_ATTR(open_ttys, S_IRUGO, open_ttys_show, NULL);

static void make_sysfs_files(struct nozomi *dc)
{
    if (device_create_file(&dc->pdev->dev, &dev_attr_card_type))
        dev_err(&dc->pdev->dev,
            "Could not create sysfs file for card_type\n");
    if (device_create_file(&dc->pdev->dev, &dev_attr_open_ttys))
        dev_err(&dc->pdev->dev,
            "Could not create sysfs file for open_ttys\n");
}

static void remove_sysfs_files(struct nozomi *dc)
{
    device_remove_file(&dc->pdev->dev, &dev_attr_card_type);
    device_remove_file(&dc->pdev->dev, &dev_attr_open_ttys);
}

/* Allocate memory for one device */
static int __devinit nozomi_card_init(struct pci_dev *pdev,
                      const struct pci_device_id *ent)
{
    resource_size_t start;
    int ret;
    struct nozomi *dc = NULL;
    int ndev_idx;
    int i;

    dev_dbg(&pdev->dev, "Init, new card found\n");

    for (ndev_idx = 0; ndev_idx < ARRAY_SIZE(ndevs); ndev_idx++)
        if (!ndevs[ndev_idx])
            break;

    if (ndev_idx >= ARRAY_SIZE(ndevs)) {
        dev_err(&pdev->dev, "no free tty range for this card left\n");
        ret = -EIO;
        goto err;
    }

    dc = kzalloc(sizeof(struct nozomi), GFP_KERNEL);
    if (unlikely(!dc)) {
        dev_err(&pdev->dev, "Could not allocate memory\n");
        ret = -ENOMEM;
        goto err_free;
    }

    dc->pdev = pdev;

    ret = pci_enable_device(dc->pdev);
    if (ret) {
        dev_err(&pdev->dev, "Failed to enable PCI Device\n");
        goto err_free;
    }

    ret = pci_request_regions(dc->pdev, NOZOMI_NAME);
    if (ret) {
        dev_err(&pdev->dev, "I/O address 0x%04x already in use\n",
            (int) /* nozomi_private.io_addr */ 0);
        goto err_disable_device;
    }

    start = pci_resource_start(dc->pdev, 0);
    if (start == 0) {
        dev_err(&pdev->dev, "No I/O address for card detected\n");
        ret = -ENODEV;
        goto err_rel_regs;
    }

    /* Find out what card type it is */
    nozomi_get_card_type(dc);

    dc->base_addr = ioremap_nocache(start, dc->card_type);
    if (!dc->base_addr) {
        dev_err(&pdev->dev, "Unable to map card MMIO\n");
        ret = -ENODEV;
        goto err_rel_regs;
    }

    dc->send_buf = kmalloc(SEND_BUF_MAX, GFP_KERNEL);
    if (!dc->send_buf) {
        dev_err(&pdev->dev, "Could not allocate send buffer?\n");
        ret = -ENOMEM;
        goto err_free_sbuf;
    }

    for (i = PORT_MDM; i < MAX_PORT; i++) {
        if (kfifo_alloc(&dc->port[i].fifo_ul, FIFO_BUFFER_SIZE_UL,
                    GFP_KERNEL)) {
            dev_err(&pdev->dev,
                    "Could not allocate kfifo buffer\n");
            ret = -ENOMEM;
            goto err_free_kfifo;
        }
    }

    spin_lock_init(&dc->spin_mutex);

    nozomi_setup_private_data(dc);

    /* Disable all interrupts */
    dc->last_ier = 0;
    writew(dc->last_ier, dc->reg_ier);

    ret = request_irq(pdev->irq, &interrupt_handler, IRQF_SHARED,
            NOZOMI_NAME, dc);
    if (unlikely(ret)) {
        dev_err(&pdev->dev, "can't request irq %d\n", pdev->irq);
        goto err_free_kfifo;
    }

    DBG1("base_addr: %p", dc->base_addr);

    make_sysfs_files(dc);

    dc->index_start = ndev_idx * MAX_PORT;
    ndevs[ndev_idx] = dc;

    pci_set_drvdata(pdev, dc);

    /* Enable RESET interrupt */
    dc->last_ier = RESET;
    iowrite16(dc->last_ier, dc->reg_ier);

    dc->state = NOZOMI_STATE_ENABLED;

    for (i = 0; i < MAX_PORT; i++) {
        struct device *tty_dev;
        struct port *port = &dc->port[i];
        port->dc = dc;
        tty_port_init(&port->port);
        port->port.ops = &noz_tty_port_ops;
        tty_dev = tty_port_register_device(&port->port, ntty_driver,
                dc->index_start + i, &pdev->dev);

        if (IS_ERR(tty_dev)) {
            ret = PTR_ERR(tty_dev);
            dev_err(&pdev->dev, "Could not allocate tty?\n");
            goto err_free_tty;
        }
    }

    return 0;

err_free_tty:
    for (i = dc->index_start; i < dc->index_start + MAX_PORT; ++i)
        tty_unregister_device(ntty_driver, i);
err_free_kfifo:
    for (i = 0; i < MAX_PORT; i++)
        kfifo_free(&dc->port[i].fifo_ul);
err_free_sbuf:
    kfree(dc->send_buf);
    iounmap(dc->base_addr);
err_rel_regs:
    pci_release_regions(pdev);
err_disable_device:
    pci_disable_device(pdev);
err_free:
    kfree(dc);
err:
    return ret;
}

static void __devexit tty_exit(struct nozomi *dc)
{
    unsigned int i;

    DBG1(" ");

    for (i = 0; i < MAX_PORT; ++i) {
        struct tty_struct *tty = tty_port_tty_get(&dc->port[i].port);
        if (tty && list_empty(&tty->hangup_work.entry))
            tty_hangup(tty);
        tty_kref_put(tty);
    }
    /* Racy below - surely should wait for scheduled work to be done or
       complete off a hangup method ? */
    while (dc->open_ttys)
        msleep(1);
    for (i = dc->index_start; i < dc->index_start + MAX_PORT; ++i)
        tty_unregister_device(ntty_driver, i);
}

/* Deallocate memory for one device */
static void __devexit nozomi_card_exit(struct pci_dev *pdev)
{
    int i;
    struct ctrl_ul ctrl;
    struct nozomi *dc = pci_get_drvdata(pdev);

    /* Disable all interrupts */
    dc->last_ier = 0;
    writew(dc->last_ier, dc->reg_ier);

    tty_exit(dc);

    /* Send 0x0001, command card to resend the reset token.  */
    /* This is to get the reset when the module is reloaded. */
    ctrl.port = 0x00;
    ctrl.reserved = 0;
    ctrl.RTS = 0;
    ctrl.DTR = 1;
    DBG1("sending flow control 0x%04X", *((u16 *)&ctrl));

    /* Setup dc->reg addresses to we can use defines here */
    write_mem32(dc->port[PORT_CTRL].ul_addr[0], (u32 *)&ctrl, 2);
    writew(CTRL_UL, dc->reg_fcr);   /* push the token to the card. */

    remove_sysfs_files(dc);

    free_irq(pdev->irq, dc);

    for (i = 0; i < MAX_PORT; i++)
        kfifo_free(&dc->port[i].fifo_ul);

    kfree(dc->send_buf);

    iounmap(dc->base_addr);

    pci_release_regions(pdev);

    pci_disable_device(pdev);

    ndevs[dc->index_start / MAX_PORT] = NULL;

    kfree(dc);
}

static void set_rts(const struct tty_struct *tty, int rts)
{
    struct port *port = get_port_by_tty(tty);

    port->ctrl_ul.RTS = rts;
    port->update_flow_control = 1;
    enable_transmit_ul(PORT_CTRL, get_dc_by_tty(tty));
}

static void set_dtr(const struct tty_struct *tty, int dtr)
{
    struct port *port = get_port_by_tty(tty);

    DBG1("SETTING DTR index: %d, dtr: %d", tty->index, dtr);

    port->ctrl_ul.DTR = dtr;
    port->update_flow_control = 1;
    enable_transmit_ul(PORT_CTRL, get_dc_by_tty(tty));
}

/*
 * ----------------------------------------------------------------------------
 * TTY code
 * ----------------------------------------------------------------------------
 */

static int ntty_install(struct tty_driver *driver, struct tty_struct *tty)
{
    struct port *port = get_port_by_tty(tty);
    struct nozomi *dc = get_dc_by_tty(tty);
    int ret;
    if (!port || !dc || dc->state != NOZOMI_STATE_READY)
        return -ENODEV;
    ret = tty_standard_install(driver, tty);
    if (ret == 0)
        tty->driver_data = port;
    return ret;
}

static void ntty_cleanup(struct tty_struct *tty)
{
    tty->driver_data = NULL;
}

static int ntty_activate(struct tty_port *tport, struct tty_struct *tty)
{
    struct port *port = container_of(tport, struct port, port);
    struct nozomi *dc = port->dc;
    unsigned long flags;

    DBG1("open: %d", port->token_dl);
    spin_lock_irqsave(&dc->spin_mutex, flags);
    dc->last_ier = dc->last_ier | port->token_dl;
    writew(dc->last_ier, dc->reg_ier);
    dc->open_ttys++;
    spin_unlock_irqrestore(&dc->spin_mutex, flags);
    printk("noz: activated %d: %p\n", tty->index, tport);
    return 0;
}

static int ntty_open(struct tty_struct *tty, struct file *filp)
{
    struct port *port = tty->driver_data;
    return tty_port_open(&port->port, tty, filp);
}

static void ntty_shutdown(struct tty_port *tport)
{
    struct port *port = container_of(tport, struct port, port);
    struct nozomi *dc = port->dc;
    unsigned long flags;

    DBG1("close: %d", port->token_dl);
    spin_lock_irqsave(&dc->spin_mutex, flags);
    dc->last_ier &= ~(port->token_dl);
    writew(dc->last_ier, dc->reg_ier);
    dc->open_ttys--;
    spin_unlock_irqrestore(&dc->spin_mutex, flags);
    printk("noz: shutdown %p\n", tport);
}

static void ntty_close(struct tty_struct *tty, struct file *filp)
{
    struct port *port = tty->driver_data;
    if (port)
        tty_port_close(&port->port, tty, filp);
}

static void ntty_hangup(struct tty_struct *tty)
{
    struct port *port = tty->driver_data;
    tty_port_hangup(&port->port);
}

/*
 * called when the userspace process writes to the tty (/dev/noz*).
 * Data is inserted into a fifo, which is then read and transferred to the modem.
 */
static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
              int count)
{
    int rval = -EINVAL;
    struct nozomi *dc = get_dc_by_tty(tty);
    struct port *port = tty->driver_data;
    unsigned long flags;

    /* DBG1( "WRITEx: %d, index = %d", count, index); */

    if (!dc || !port)
        return -ENODEV;

    rval = kfifo_in(&port->fifo_ul, (unsigned char *)buffer, count);

    /* notify card */
    if (unlikely(dc == NULL)) {
        DBG1("No device context?");
        goto exit;
    }

    spin_lock_irqsave(&dc->spin_mutex, flags);
    /* CTS is only valid on the modem channel */
    if (port == &(dc->port[PORT_MDM])) {
        if (port->ctrl_dl.CTS) {
            DBG4("Enable interrupt");
            enable_transmit_ul(tty->index % MAX_PORT, dc);
        } else {
            dev_err(&dc->pdev->dev,
                "CTS not active on modem port?\n");
        }
    } else {
        enable_transmit_ul(tty->index % MAX_PORT, dc);
    }
    spin_unlock_irqrestore(&dc->spin_mutex, flags);

exit:
    return rval;
}

/*
 * Calculate how much is left in device
 * This method is called by the upper tty layer.
 *   #according to sources N_TTY.c it expects a value >= 0 and
 *    does not check for negative values.
 *
 * If the port is unplugged report lots of room and let the bits
 * dribble away so we don't block anything.
 */
static int ntty_write_room(struct tty_struct *tty)
{
    struct port *port = tty->driver_data;
    int room = 4096;
    const struct nozomi *dc = get_dc_by_tty(tty);

    if (dc)
        room = kfifo_avail(&port->fifo_ul);

    return room;
}

/* Gets io control parameters */
static int ntty_tiocmget(struct tty_struct *tty)
{
    const struct port *port = tty->driver_data;
    const struct ctrl_dl *ctrl_dl = &port->ctrl_dl;
    const struct ctrl_ul *ctrl_ul = &port->ctrl_ul;

    /* Note: these could change under us but it is not clear this
       matters if so */
    return  (ctrl_ul->RTS ? TIOCM_RTS : 0) |
        (ctrl_ul->DTR ? TIOCM_DTR : 0) |
        (ctrl_dl->DCD ? TIOCM_CAR : 0) |
        (ctrl_dl->RI  ? TIOCM_RNG : 0) |
        (ctrl_dl->DSR ? TIOCM_DSR : 0) |
        (ctrl_dl->CTS ? TIOCM_CTS : 0);
}

/* Sets io controls parameters */
static int ntty_tiocmset(struct tty_struct *tty,
                    unsigned int set, unsigned int clear)
{
    struct nozomi *dc = get_dc_by_tty(tty);
    unsigned long flags;

    spin_lock_irqsave(&dc->spin_mutex, flags);
    if (set & TIOCM_RTS)
        set_rts(tty, 1);
    else if (clear & TIOCM_RTS)
        set_rts(tty, 0);

    if (set & TIOCM_DTR)
        set_dtr(tty, 1);
    else if (clear & TIOCM_DTR)
        set_dtr(tty, 0);
    spin_unlock_irqrestore(&dc->spin_mutex, flags);

    return 0;
}

static int ntty_cflags_changed(struct port *port, unsigned long flags,
        struct async_icount *cprev)
{
    const struct async_icount cnow = port->tty_icount;
    int ret;

    ret =   ((flags & TIOCM_RNG) && (cnow.rng != cprev->rng)) ||
        ((flags & TIOCM_DSR) && (cnow.dsr != cprev->dsr)) ||
        ((flags & TIOCM_CD)  && (cnow.dcd != cprev->dcd)) ||
        ((flags & TIOCM_CTS) && (cnow.cts != cprev->cts));

    *cprev = cnow;

    return ret;
}

static int ntty_tiocgicount(struct tty_struct *tty,
                struct serial_icounter_struct *icount)
{
    struct port *port = tty->driver_data;
    const struct async_icount cnow = port->tty_icount;

    icount->cts = cnow.cts;
    icount->dsr = cnow.dsr;
    icount->rng = cnow.rng;
    icount->dcd = cnow.dcd;
    icount->rx = cnow.rx;
    icount->tx = cnow.tx;
    icount->frame = cnow.frame;
    icount->overrun = cnow.overrun;
    icount->parity = cnow.parity;
    icount->brk = cnow.brk;
    icount->buf_overrun = cnow.buf_overrun;
    return 0;
}

static int ntty_ioctl(struct tty_struct *tty,
              unsigned int cmd, unsigned long arg)
{
    struct port *port = tty->driver_data;
    int rval = -ENOIOCTLCMD;

    DBG1("******** IOCTL, cmd: %d", cmd);

    switch (cmd) {
    case TIOCMIWAIT: {
        struct async_icount cprev = port->tty_icount;

        rval = wait_event_interruptible(port->tty_wait,
                ntty_cflags_changed(port, arg, &cprev));
        break;
    }
    default:
        DBG1("ERR: 0x%08X, %d", cmd, cmd);
        break;
    };

    return rval;
}

/*
 * Called by the upper tty layer when tty buffers are ready
 * to receive data again after a call to throttle.
 */
static void ntty_unthrottle(struct tty_struct *tty)
{
    struct nozomi *dc = get_dc_by_tty(tty);
    unsigned long flags;

    DBG1("UNTHROTTLE");
    spin_lock_irqsave(&dc->spin_mutex, flags);
    enable_transmit_dl(tty->index % MAX_PORT, dc);
    set_rts(tty, 1);

    spin_unlock_irqrestore(&dc->spin_mutex, flags);
}

/*
 * Called by the upper tty layer when the tty buffers are almost full.
 * The driver should stop send more data.
 */
static void ntty_throttle(struct tty_struct *tty)
{
    struct nozomi *dc = get_dc_by_tty(tty);
    unsigned long flags;

    DBG1("THROTTLE");
    spin_lock_irqsave(&dc->spin_mutex, flags);
    set_rts(tty, 0);
    spin_unlock_irqrestore(&dc->spin_mutex, flags);
}

/* Returns number of chars in buffer, called by tty layer */
static s32 ntty_chars_in_buffer(struct tty_struct *tty)
{
    struct port *port = tty->driver_data;
    struct nozomi *dc = get_dc_by_tty(tty);
    s32 rval = 0;

    if (unlikely(!dc || !port)) {
        goto exit_in_buffer;
    }

    rval = kfifo_len(&port->fifo_ul);

exit_in_buffer:
    return rval;
}

static const struct tty_port_operations noz_tty_port_ops = {
    .activate = ntty_activate,
    .shutdown = ntty_shutdown,
};

static const struct tty_operations tty_ops = {
    .ioctl = ntty_ioctl,
    .open = ntty_open,
    .close = ntty_close,
    .hangup = ntty_hangup,
    .write = ntty_write,
    .write_room = ntty_write_room,
    .unthrottle = ntty_unthrottle,
    .throttle = ntty_throttle,
    .chars_in_buffer = ntty_chars_in_buffer,
    .tiocmget = ntty_tiocmget,
    .tiocmset = ntty_tiocmset,
    .get_icount = ntty_tiocgicount,
    .install = ntty_install,
    .cleanup = ntty_cleanup,
};

/* Module initialization */
static struct pci_driver nozomi_driver = {
    .name = NOZOMI_NAME,
    .id_table = nozomi_pci_tbl,
    .probe = nozomi_card_init,
    .remove = __devexit_p(nozomi_card_exit),
};

static __init int nozomi_init(void)
{
    int ret;

    printk(KERN_INFO "Initializing %s\n", VERSION_STRING);

    ntty_driver = alloc_tty_driver(NTTY_TTY_MAXMINORS);
    if (!ntty_driver)
        return -ENOMEM;

    ntty_driver->driver_name = NOZOMI_NAME_TTY;
    ntty_driver->name = "noz";
    ntty_driver->major = 0;
    ntty_driver->type = TTY_DRIVER_TYPE_SERIAL;
    ntty_driver->subtype = SERIAL_TYPE_NORMAL;
    ntty_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
    ntty_driver->init_termios = tty_std_termios;
    ntty_driver->init_termios.c_cflag = B115200 | CS8 | CREAD | \
                        HUPCL | CLOCAL;
    ntty_driver->init_termios.c_ispeed = 115200;
    ntty_driver->init_termios.c_ospeed = 115200;
    tty_set_operations(ntty_driver, &tty_ops);

    ret = tty_register_driver(ntty_driver);
    if (ret) {
        printk(KERN_ERR "Nozomi: failed to register ntty driver\n");
        goto free_tty;
    }

    ret = pci_register_driver(&nozomi_driver);
    if (ret) {
        printk(KERN_ERR "Nozomi: can't register pci driver\n");
        goto unr_tty;
    }

    return 0;
unr_tty:
    tty_unregister_driver(ntty_driver);
free_tty:
    put_tty_driver(ntty_driver);
    return ret;
}

static __exit void nozomi_exit(void)
{
    printk(KERN_INFO "Unloading %s\n", DRIVER_DESC);
    pci_unregister_driver(&nozomi_driver);
    tty_unregister_driver(ntty_driver);
    put_tty_driver(ntty_driver);
}

module_init(nozomi_init);
module_exit(nozomi_exit);

module_param(debug, int, S_IRUGO | S_IWUSR);

MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION(DRIVER_DESC);