/*
 * Driver for the VoIP USB phones with CM109 chipsets.
 *
 * Copyright (C) 2007 - 2008 Alfred E. Heggestad <aeh@db.org>
 *
 *      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, version 2.
 */

/*
 *   Tested devices:
 *      - Komunikate KIP1000
 *      - Genius G-talk
 *      - Allied-Telesis Corega USBPH01
 *      - ...
 *
 * This driver is based on the yealink.c driver
 *
 * Thanks to:
 *   - Authors of yealink.c
 *   - Thomas Reitmayr
 *   - Oliver Neukum for good review comments and code
 *   - Shaun Jackman <sjackman@gmail.com> for Genius G-talk keymap
 *   - Dmitry Torokhov for valuable input and review
 *
 * Todo:
 *   - Read/write EEPROM
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/rwsem.h>
#include <linux/usb/input.h>

#define DRIVER_VERSION "20080805"
#define DRIVER_AUTHOR  "Alfred E. Heggestad"
#define DRIVER_DESC    "CM109 phone driver"

static char *phone = "kip1000";
module_param(phone, charp, S_IRUSR);
MODULE_PARM_DESC(phone, "Phone name {kip1000, gtalk, usbph01, atcom}");

enum {
        /* HID Registers */
        HID_IR0 = 0x00, /* Record/Playback-mute button, Volume up/down  */
        HID_IR1 = 0x01, /* GPI, generic registers or EEPROM_DATA0       */
        HID_IR2 = 0x02, /* Generic registers or EEPROM_DATA1            */
        HID_IR3 = 0x03, /* Generic registers or EEPROM_CTRL             */
        HID_OR0 = 0x00, /* Mapping control, buzzer, SPDIF (offset 0x04) */
        HID_OR1 = 0x01, /* GPO - General Purpose Output                 */
        HID_OR2 = 0x02, /* Set GPIO to input/output mode                */
        HID_OR3 = 0x03, /* SPDIF status channel or EEPROM_CTRL          */

        /* HID_IR0 */
        RECORD_MUTE   = 1 << 3,
        PLAYBACK_MUTE = 1 << 2,
        VOLUME_DOWN   = 1 << 1,
        VOLUME_UP     = 1 << 0,

        /* HID_OR0 */
        /* bits 7-6
           0: HID_OR1-2 are used for GPO; HID_OR0, 3 are used for buzzer
              and SPDIF
           1: HID_OR0-3 are used as generic HID registers
           2: Values written to HID_OR0-3 are also mapped to MCU_CTRL,
              EEPROM_DATA0-1, EEPROM_CTRL (see Note)
           3: Reserved
         */
        HID_OR_GPO_BUZ_SPDIF   = 0 << 6,
        HID_OR_GENERIC_HID_REG = 1 << 6,
        HID_OR_MAP_MCU_EEPROM  = 2 << 6,

        BUZZER_ON = 1 << 5,

        /* up to 256 normal keys, up to 15 special key combinations */
        KEYMAP_SIZE = 256 + 15,
};

/* CM109 protocol packet */
struct cm109_ctl_packet {
        u8 byte[4];
} __attribute__ ((packed));

enum { USB_PKT_LEN = sizeof(struct cm109_ctl_packet) };

/* CM109 device structure */
struct cm109_dev {
        struct input_dev *idev;  /* input device */
        struct usb_device *udev; /* usb device */
        struct usb_interface *intf;

        /* irq input channel */
        struct cm109_ctl_packet *irq_data;
        dma_addr_t irq_dma;
        struct urb *urb_irq;

        /* control output channel */
        struct cm109_ctl_packet *ctl_data;
        dma_addr_t ctl_dma;
        struct usb_ctrlrequest *ctl_req;
        struct urb *urb_ctl;
        /*
         * The 3 bitfields below are protected by ctl_submit_lock.
         * They have to be separate since they are accessed from IRQ
         * context.
         */
        unsigned irq_urb_pending:1;     /* irq_urb is in flight */
        unsigned ctl_urb_pending:1;     /* ctl_urb is in flight */
        unsigned buzzer_pending:1;      /* need to issue buzz command */
        spinlock_t ctl_submit_lock;

        unsigned char buzzer_state;     /* on/off */

        /* flags */
        unsigned open:1;
        unsigned resetting:1;
        unsigned shutdown:1;

        /* This mutex protects writes to the above flags */
        struct mutex pm_mutex;

        unsigned short keymap[KEYMAP_SIZE];

        char phys[64];          /* physical device path */
        int key_code;           /* last reported key */
        int keybit;             /* 0=new scan  1,2,4,8=scan columns  */
        u8 gpi;                 /* Cached value of GPI (high nibble) */
};

/******************************************************************************
 * CM109 key interface
 *****************************************************************************/

static unsigned short special_keymap(int code)
{
        if (code > 0xff) {
                switch (code - 0xff) {
                case RECORD_MUTE:       return KEY_MICMUTE;
                case PLAYBACK_MUTE:     return KEY_MUTE;
                case VOLUME_DOWN:       return KEY_VOLUMEDOWN;
                case VOLUME_UP:         return KEY_VOLUMEUP;
                }
        }
        return KEY_RESERVED;
}

/* Map device buttons to internal key events.
 *
 * The "up" and "down" keys, are symbolised by arrows on the button.
 * The "pickup" and "hangup" keys are symbolised by a green and red phone
 * on the button.

 Komunikate KIP1000 Keyboard Matrix

     -> -- 1 -- 2 -- 3  --> GPI pin 4 (0x10)
      |    |    |    |
     <- -- 4 -- 5 -- 6  --> GPI pin 5 (0x20)
      |    |    |    |
     END - 7 -- 8 -- 9  --> GPI pin 6 (0x40)
      |    |    |    |
     OK -- * -- 0 -- #  --> GPI pin 7 (0x80)
      |    |    |    |

     /|\  /|\  /|\  /|\
      |    |    |    |
GPO
pin:  3    2    1    0
     0x8  0x4  0x2  0x1

 */
static unsigned short keymap_kip1000(int scancode)
{
        switch (scancode) {                             /* phone key:   */
        case 0x82: return KEY_NUMERIC_0;                /*   0          */
        case 0x14: return KEY_NUMERIC_1;                /*   1          */
        case 0x12: return KEY_NUMERIC_2;                /*   2          */
        case 0x11: return KEY_NUMERIC_3;                /*   3          */
        case 0x24: return KEY_NUMERIC_4;                /*   4          */
        case 0x22: return KEY_NUMERIC_5;                /*   5          */
        case 0x21: return KEY_NUMERIC_6;                /*   6          */
        case 0x44: return KEY_NUMERIC_7;                /*   7          */
        case 0x42: return KEY_NUMERIC_8;                /*   8          */
        case 0x41: return KEY_NUMERIC_9;                /*   9          */
        case 0x81: return KEY_NUMERIC_POUND;            /*   #          */
        case 0x84: return KEY_NUMERIC_STAR;             /*   *          */
        case 0x88: return KEY_ENTER;                    /*   pickup     */
        case 0x48: return KEY_ESC;                      /*   hangup     */
        case 0x28: return KEY_LEFT;                     /*   IN         */
        case 0x18: return KEY_RIGHT;                    /*   OUT        */
        default:   return special_keymap(scancode);
        }
}

/*
  Contributed by Shaun Jackman <sjackman@gmail.com>

  Genius G-Talk keyboard matrix
     0 1 2 3
  4: 0 4 8 Talk
  5: 1 5 9 End
  6: 2 6 # Up
  7: 3 7 * Down
*/
static unsigned short keymap_gtalk(int scancode)
{
        switch (scancode) {
        case 0x11: return KEY_NUMERIC_0;
        case 0x21: return KEY_NUMERIC_1;
        case 0x41: return KEY_NUMERIC_2;
        case 0x81: return KEY_NUMERIC_3;
        case 0x12: return KEY_NUMERIC_4;
        case 0x22: return KEY_NUMERIC_5;
        case 0x42: return KEY_NUMERIC_6;
        case 0x82: return KEY_NUMERIC_7;
        case 0x14: return KEY_NUMERIC_8;
        case 0x24: return KEY_NUMERIC_9;
        case 0x44: return KEY_NUMERIC_POUND;    /* # */
        case 0x84: return KEY_NUMERIC_STAR;     /* * */
        case 0x18: return KEY_ENTER;            /* Talk (green handset) */
        case 0x28: return KEY_ESC;              /* End (red handset) */
        case 0x48: return KEY_UP;               /* Menu up (rocker switch) */
        case 0x88: return KEY_DOWN;             /* Menu down (rocker switch) */
        default:   return special_keymap(scancode);
        }
}

/*
 * Keymap for Allied-Telesis Corega USBPH01
 * http://www.alliedtelesis-corega.com/2/1344/1437/1360/chprd.html
 *
 * Contributed by july@nat.bg
 */
static unsigned short keymap_usbph01(int scancode)
{
        switch (scancode) {
        case 0x11: return KEY_NUMERIC_0;                /*   0          */
        case 0x21: return KEY_NUMERIC_1;                /*   1          */
        case 0x41: return KEY_NUMERIC_2;                /*   2          */
        case 0x81: return KEY_NUMERIC_3;                /*   3          */
        case 0x12: return KEY_NUMERIC_4;                /*   4          */
        case 0x22: return KEY_NUMERIC_5;                /*   5          */
        case 0x42: return KEY_NUMERIC_6;                /*   6          */
        case 0x82: return KEY_NUMERIC_7;                /*   7          */
        case 0x14: return KEY_NUMERIC_8;                /*   8          */
        case 0x24: return KEY_NUMERIC_9;                /*   9          */
        case 0x44: return KEY_NUMERIC_POUND;            /*   #          */
        case 0x84: return KEY_NUMERIC_STAR;             /*   *          */
        case 0x18: return KEY_ENTER;                    /*   pickup     */
        case 0x28: return KEY_ESC;                      /*   hangup     */
        case 0x48: return KEY_LEFT;                     /*   IN         */
        case 0x88: return KEY_RIGHT;                    /*   OUT        */
        default:   return special_keymap(scancode);
        }
}

/*
 * Keymap for ATCom AU-100
 * http://www.atcom.cn/products.html 
 * http://www.packetizer.com/products/au100/
 * http://www.voip-info.org/wiki/view/AU-100
 *
 * Contributed by daniel@gimpelevich.san-francisco.ca.us
 */
static unsigned short keymap_atcom(int scancode)
{
        switch (scancode) {                             /* phone key:   */
        case 0x82: return KEY_NUMERIC_0;                /*   0          */
        case 0x11: return KEY_NUMERIC_1;                /*   1          */
        case 0x12: return KEY_NUMERIC_2;                /*   2          */
        case 0x14: return KEY_NUMERIC_3;                /*   3          */
        case 0x21: return KEY_NUMERIC_4;                /*   4          */
        case 0x22: return KEY_NUMERIC_5;                /*   5          */
        case 0x24: return KEY_NUMERIC_6;                /*   6          */
        case 0x41: return KEY_NUMERIC_7;                /*   7          */
        case 0x42: return KEY_NUMERIC_8;                /*   8          */
        case 0x44: return KEY_NUMERIC_9;                /*   9          */
        case 0x84: return KEY_NUMERIC_POUND;            /*   #          */
        case 0x81: return KEY_NUMERIC_STAR;             /*   *          */
        case 0x18: return KEY_ENTER;                    /*   pickup     */
        case 0x28: return KEY_ESC;                      /*   hangup     */
        case 0x48: return KEY_LEFT;                     /* left arrow   */
        case 0x88: return KEY_RIGHT;                    /* right arrow  */
        default:   return special_keymap(scancode);
        }
}

static unsigned short (*keymap)(int) = keymap_kip1000;

/*
 * Completes a request by converting the data into events for the
 * input subsystem.
 */
static void report_key(struct cm109_dev *dev, int key)
{
        struct input_dev *idev = dev->idev;

        if (dev->key_code >= 0) {
                /* old key up */
                input_report_key(idev, dev->key_code, 0);
        }

        dev->key_code = key;
        if (key >= 0) {
                /* new valid key */
                input_report_key(idev, key, 1);
        }

        input_sync(idev);
}

/*
 * Converts data of special key presses (volume, mute) into events
 * for the input subsystem, sends press-n-release for mute keys.
 */
static void cm109_report_special(struct cm109_dev *dev)
{
        static const u8 autorelease = RECORD_MUTE | PLAYBACK_MUTE;
        struct input_dev *idev = dev->idev;
        u8 data = dev->irq_data->byte[HID_IR0];
        unsigned short keycode;
        int i;

        for (i = 0; i < 4; i++) {
                keycode = dev->keymap[0xff + BIT(i)];
                if (keycode == KEY_RESERVED)
                        continue;

                input_report_key(idev, keycode, data & BIT(i));
                if (data & autorelease & BIT(i)) {
                        input_sync(idev);
                        input_report_key(idev, keycode, 0);
                }
        }
        input_sync(idev);
}

/******************************************************************************
 * CM109 usb communication interface
 *****************************************************************************/

static void cm109_submit_buzz_toggle(struct cm109_dev *dev)
{
        int error;

        if (dev->buzzer_state)
                dev->ctl_data->byte[HID_OR0] |= BUZZER_ON;
        else
                dev->ctl_data->byte[HID_OR0] &= ~BUZZER_ON;

        error = usb_submit_urb(dev->urb_ctl, GFP_ATOMIC);
        if (error)
                dev_err(&dev->intf->dev,
                        "%s: usb_submit_urb (urb_ctl) failed %d\n",
                        __func__, error);
}

/*
 * IRQ handler
 */
static void cm109_urb_irq_callback(struct urb *urb)
{
        struct cm109_dev *dev = urb->context;
        const int status = urb->status;
        int error;
        unsigned long flags;

        dev_dbg(&dev->intf->dev, "### URB IRQ: [0x%02x 0x%02x 0x%02x 0x%02x] keybit=0x%02x\n",
             dev->irq_data->byte[0],
             dev->irq_data->byte[1],
             dev->irq_data->byte[2],
             dev->irq_data->byte[3],
             dev->keybit);

        if (status) {
                if (status == -ESHUTDOWN)
                        return;
                dev_err_ratelimited(&dev->intf->dev, "%s: urb status %d\n",
                                    __func__, status);
                goto out;
        }

        /* Special keys */
        cm109_report_special(dev);

        /* Scan key column */
        if (dev->keybit == 0xf) {

                /* Any changes ? */
                if ((dev->gpi & 0xf0) == (dev->irq_data->byte[HID_IR1] & 0xf0))
                        goto out;

                dev->gpi = dev->irq_data->byte[HID_IR1] & 0xf0;
                dev->keybit = 0x1;
        } else {
                report_key(dev, dev->keymap[dev->irq_data->byte[HID_IR1]]);

                dev->keybit <<= 1;
                if (dev->keybit > 0x8)
                        dev->keybit = 0xf;
        }

 out:

        spin_lock_irqsave(&dev->ctl_submit_lock, flags);

        dev->irq_urb_pending = 0;

        if (likely(!dev->shutdown)) {

                if (dev->buzzer_state)
                        dev->ctl_data->byte[HID_OR0] |= BUZZER_ON;
                else
                        dev->ctl_data->byte[HID_OR0] &= ~BUZZER_ON;

                dev->ctl_data->byte[HID_OR1] = dev->keybit;
                dev->ctl_data->byte[HID_OR2] = dev->keybit;

                dev->buzzer_pending = 0;
                dev->ctl_urb_pending = 1;

                error = usb_submit_urb(dev->urb_ctl, GFP_ATOMIC);
                if (error)
                        dev_err(&dev->intf->dev,
                                "%s: usb_submit_urb (urb_ctl) failed %d\n",
                                __func__, error);
        }

        spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
}

static void cm109_urb_ctl_callback(struct urb *urb)
{
        struct cm109_dev *dev = urb->context;
        const int status = urb->status;
        int error;
        unsigned long flags;

        dev_dbg(&dev->intf->dev, "### URB CTL: [0x%02x 0x%02x 0x%02x 0x%02x]\n",
             dev->ctl_data->byte[0],
             dev->ctl_data->byte[1],
             dev->ctl_data->byte[2],
             dev->ctl_data->byte[3]);

        if (status) {
                if (status == -ESHUTDOWN)
                        return;
                dev_err_ratelimited(&dev->intf->dev, "%s: urb status %d\n",
                                    __func__, status);
        }

        spin_lock_irqsave(&dev->ctl_submit_lock, flags);

        dev->ctl_urb_pending = 0;

        if (likely(!dev->shutdown)) {

                if (dev->buzzer_pending || status) {
                        dev->buzzer_pending = 0;
                        dev->ctl_urb_pending = 1;
                        cm109_submit_buzz_toggle(dev);
                } else if (likely(!dev->irq_urb_pending)) {
                        /* ask for key data */
                        dev->irq_urb_pending = 1;
                        error = usb_submit_urb(dev->urb_irq, GFP_ATOMIC);
                        if (error)
                                dev_err(&dev->intf->dev,
                                        "%s: usb_submit_urb (urb_irq) failed %d\n",
                                        __func__, error);
                }
        }

        spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
}

static void cm109_toggle_buzzer_async(struct cm109_dev *dev)
{
        unsigned long flags;

        spin_lock_irqsave(&dev->ctl_submit_lock, flags);

        if (dev->ctl_urb_pending) {
                /* URB completion will resubmit */
                dev->buzzer_pending = 1;
        } else {
                dev->ctl_urb_pending = 1;
                cm109_submit_buzz_toggle(dev);
        }

        spin_unlock_irqrestore(&dev->ctl_submit_lock, flags);
}

static void cm109_toggle_buzzer_sync(struct cm109_dev *dev, int on)
{
        int error;

        if (on)
                dev->ctl_data->byte[HID_OR0] |= BUZZER_ON;
        else
                dev->ctl_data->byte[HID_OR0] &= ~BUZZER_ON;

        error = usb_control_msg(dev->udev,
                                usb_sndctrlpipe(dev->udev, 0),
                                dev->ctl_req->bRequest,
                                dev->ctl_req->bRequestType,
                                le16_to_cpu(dev->ctl_req->wValue),
                                le16_to_cpu(dev->ctl_req->wIndex),
                                dev->ctl_data,
                                USB_PKT_LEN, USB_CTRL_SET_TIMEOUT);
        if (error < 0 && error != -EINTR)
                dev_err(&dev->intf->dev, "%s: usb_control_msg() failed %d\n",
                        __func__, error);
}

static void cm109_stop_traffic(struct cm109_dev *dev)
{
        dev->shutdown = 1;
        /*
         * Make sure other CPUs see this
         */
        smp_wmb();

        usb_kill_urb(dev->urb_ctl);
        usb_kill_urb(dev->urb_irq);

        cm109_toggle_buzzer_sync(dev, 0);

        dev->shutdown = 0;
        smp_wmb();
}

static void cm109_restore_state(struct cm109_dev *dev)
{
        if (dev->open) {
                /*
                 * Restore buzzer state.
                 * This will also kick regular URB submission
                 */
                cm109_toggle_buzzer_async(dev);
        }
}

/******************************************************************************
 * input event interface
 *****************************************************************************/

static int cm109_input_open(struct input_dev *idev)
{
        struct cm109_dev *dev = input_get_drvdata(idev);
        int error;

        error = usb_autopm_get_interface(dev->intf);
        if (error < 0) {
                dev_err(&idev->dev, "%s - cannot autoresume, result %d\n",
                        __func__, error);
                return error;
        }

        mutex_lock(&dev->pm_mutex);

        dev->buzzer_state = 0;
        dev->key_code = -1;     /* no keys pressed */
        dev->keybit = 0xf;

        /* issue INIT */
        dev->ctl_data->byte[HID_OR0] = HID_OR_GPO_BUZ_SPDIF;
        dev->ctl_data->byte[HID_OR1] = dev->keybit;
        dev->ctl_data->byte[HID_OR2] = dev->keybit;
        dev->ctl_data->byte[HID_OR3] = 0x00;

        error = usb_submit_urb(dev->urb_ctl, GFP_KERNEL);
        if (error)
                dev_err(&dev->intf->dev, "%s: usb_submit_urb (urb_ctl) failed %d\n",
                        __func__, error);
        else
                dev->open = 1;

        mutex_unlock(&dev->pm_mutex);

        if (error)
                usb_autopm_put_interface(dev->intf);

        return error;
}

static void cm109_input_close(struct input_dev *idev)
{
        struct cm109_dev *dev = input_get_drvdata(idev);

        mutex_lock(&dev->pm_mutex);

        /*
         * Once we are here event delivery is stopped so we
         * don't need to worry about someone starting buzzer
         * again
         */
        cm109_stop_traffic(dev);
        dev->open = 0;

        mutex_unlock(&dev->pm_mutex);

        usb_autopm_put_interface(dev->intf);
}

static int cm109_input_ev(struct input_dev *idev, unsigned int type,
                          unsigned int code, int value)
{
        struct cm109_dev *dev = input_get_drvdata(idev);

        dev_dbg(&dev->intf->dev,
                "input_ev: type=%u code=%u value=%d\n", type, code, value);

        if (type != EV_SND)
                return -EINVAL;

        switch (code) {
        case SND_TONE:
        case SND_BELL:
                dev->buzzer_state = !!value;
                if (!dev->resetting)
                        cm109_toggle_buzzer_async(dev);
                return 0;

        default:
                return -EINVAL;
        }
}


/******************************************************************************
 * Linux interface and usb initialisation
 *****************************************************************************/

struct driver_info {
        char *name;
};

static const struct driver_info info_cm109 = {
        .name = "CM109 USB driver",
};

enum {
        VENDOR_ID        = 0x0d8c, /* C-Media Electronics */
        PRODUCT_ID_CM109 = 0x000e, /* CM109 defines range 0x0008 - 0x000f */
};

/* table of devices that work with this driver */
static const struct usb_device_id cm109_usb_table[] = {
        {
                .match_flags = USB_DEVICE_ID_MATCH_DEVICE |
                                USB_DEVICE_ID_MATCH_INT_INFO,
                .idVendor = VENDOR_ID,
                .idProduct = PRODUCT_ID_CM109,
                .bInterfaceClass = USB_CLASS_HID,
                .bInterfaceSubClass = 0,
                .bInterfaceProtocol = 0,
                .driver_info = (kernel_ulong_t) &info_cm109
        },
        /* you can add more devices here with product ID 0x0008 - 0x000f */
        { }
};

static void cm109_usb_cleanup(struct cm109_dev *dev)
{
        kfree(dev->ctl_req);
        if (dev->ctl_data)
                usb_free_coherent(dev->udev, USB_PKT_LEN,
                                  dev->ctl_data, dev->ctl_dma);
        if (dev->irq_data)
                usb_free_coherent(dev->udev, USB_PKT_LEN,
                                  dev->irq_data, dev->irq_dma);

        usb_free_urb(dev->urb_irq);     /* parameter validation in core/urb */
        usb_free_urb(dev->urb_ctl);     /* parameter validation in core/urb */
        kfree(dev);
}

static void cm109_usb_disconnect(struct usb_interface *interface)
{
        struct cm109_dev *dev = usb_get_intfdata(interface);

        usb_set_intfdata(interface, NULL);
        input_unregister_device(dev->idev);
        cm109_usb_cleanup(dev);
}

static int cm109_usb_probe(struct usb_interface *intf,
                           const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(intf);
        struct driver_info *nfo = (struct driver_info *)id->driver_info;
        struct usb_host_interface *interface;
        struct usb_endpoint_descriptor *endpoint;
        struct cm109_dev *dev;
        struct input_dev *input_dev = NULL;
        int ret, pipe, i;
        int error = -ENOMEM;

        interface = intf->cur_altsetting;

        if (interface->desc.bNumEndpoints < 1)
                return -ENODEV;

        endpoint = &interface->endpoint[0].desc;

        if (!usb_endpoint_is_int_in(endpoint))
                return -ENODEV;

        dev = kzalloc(sizeof(*dev), GFP_KERNEL);
        if (!dev)
                return -ENOMEM;

        spin_lock_init(&dev->ctl_submit_lock);
        mutex_init(&dev->pm_mutex);

        dev->udev = udev;
        dev->intf = intf;

        dev->idev = input_dev = input_allocate_device();
        if (!input_dev)
                goto err_out;

        /* allocate usb buffers */
        dev->irq_data = usb_alloc_coherent(udev, USB_PKT_LEN,
                                           GFP_KERNEL, &dev->irq_dma);
        if (!dev->irq_data)
                goto err_out;

        dev->ctl_data = usb_alloc_coherent(udev, USB_PKT_LEN,
                                           GFP_KERNEL, &dev->ctl_dma);
        if (!dev->ctl_data)
                goto err_out;

        dev->ctl_req = kmalloc(sizeof(*(dev->ctl_req)), GFP_KERNEL);
        if (!dev->ctl_req)
                goto err_out;

        /* allocate urb structures */
        dev->urb_irq = usb_alloc_urb(0, GFP_KERNEL);
        if (!dev->urb_irq)
                goto err_out;

        dev->urb_ctl = usb_alloc_urb(0, GFP_KERNEL);
        if (!dev->urb_ctl)
                goto err_out;

        /* get a handle to the interrupt data pipe */
        pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress);
        ret = usb_maxpacket(udev, pipe, usb_pipeout(pipe));
        if (ret != USB_PKT_LEN)
                dev_err(&intf->dev, "invalid payload size %d, expected %d\n",
                        ret, USB_PKT_LEN);

        /* initialise irq urb */
        usb_fill_int_urb(dev->urb_irq, udev, pipe, dev->irq_data,
                         USB_PKT_LEN,
                         cm109_urb_irq_callback, dev, endpoint->bInterval);
        dev->urb_irq->transfer_dma = dev->irq_dma;
        dev->urb_irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
        dev->urb_irq->dev = udev;

        /* initialise ctl urb */
        dev->ctl_req->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE |
                                        USB_DIR_OUT;
        dev->ctl_req->bRequest = USB_REQ_SET_CONFIGURATION;
        dev->ctl_req->wValue = cpu_to_le16(0x200);
        dev->ctl_req->wIndex = cpu_to_le16(interface->desc.bInterfaceNumber);
        dev->ctl_req->wLength = cpu_to_le16(USB_PKT_LEN);

        usb_fill_control_urb(dev->urb_ctl, udev, usb_sndctrlpipe(udev, 0),
                             (void *)dev->ctl_req, dev->ctl_data, USB_PKT_LEN,
                             cm109_urb_ctl_callback, dev);
        dev->urb_ctl->transfer_dma = dev->ctl_dma;
        dev->urb_ctl->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
        dev->urb_ctl->dev = udev;

        /* find out the physical bus location */
        usb_make_path(udev, dev->phys, sizeof(dev->phys));
        strlcat(dev->phys, "/input0", sizeof(dev->phys));

        /* register settings for the input device */
        input_dev->name = nfo->name;
        input_dev->phys = dev->phys;
        usb_to_input_id(udev, &input_dev->id);
        input_dev->dev.parent = &intf->dev;

        input_set_drvdata(input_dev, dev);
        input_dev->open = cm109_input_open;
        input_dev->close = cm109_input_close;
        input_dev->event = cm109_input_ev;

        input_dev->keycode = dev->keymap;
        input_dev->keycodesize = sizeof(unsigned char);
        input_dev->keycodemax = ARRAY_SIZE(dev->keymap);

        input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_SND);
        input_dev->sndbit[0] = BIT_MASK(SND_BELL) | BIT_MASK(SND_TONE);

        /* register available key events */
        for (i = 0; i < KEYMAP_SIZE; i++) {
                unsigned short k = keymap(i);
                dev->keymap[i] = k;
                __set_bit(k, input_dev->keybit);
        }
        __clear_bit(KEY_RESERVED, input_dev->keybit);

        error = input_register_device(dev->idev);
        if (error)
                goto err_out;

        usb_set_intfdata(intf, dev);

        return 0;

 err_out:
        input_free_device(input_dev);
        cm109_usb_cleanup(dev);
        return error;
}

static int cm109_usb_suspend(struct usb_interface *intf, pm_message_t message)
{
        struct cm109_dev *dev = usb_get_intfdata(intf);

        dev_info(&intf->dev, "cm109: usb_suspend (event=%d)\n", message.event);

        mutex_lock(&dev->pm_mutex);
        cm109_stop_traffic(dev);
        mutex_unlock(&dev->pm_mutex);

        return 0;
}

static int cm109_usb_resume(struct usb_interface *intf)
{
        struct cm109_dev *dev = usb_get_intfdata(intf);

        dev_info(&intf->dev, "cm109: usb_resume\n");

        mutex_lock(&dev->pm_mutex);
        cm109_restore_state(dev);
        mutex_unlock(&dev->pm_mutex);

        return 0;
}

static int cm109_usb_pre_reset(struct usb_interface *intf)
{
        struct cm109_dev *dev = usb_get_intfdata(intf);

        mutex_lock(&dev->pm_mutex);

        /*
         * Make sure input events don't try to toggle buzzer
         * while we are resetting
         */
        dev->resetting = 1;
        smp_wmb();

        cm109_stop_traffic(dev);

        return 0;
}

static int cm109_usb_post_reset(struct usb_interface *intf)
{
        struct cm109_dev *dev = usb_get_intfdata(intf);

        dev->resetting = 0;
        smp_wmb();

        cm109_restore_state(dev);

        mutex_unlock(&dev->pm_mutex);

        return 0;
}

static struct usb_driver cm109_driver = {
        .name           = "cm109",
        .probe          = cm109_usb_probe,
        .disconnect     = cm109_usb_disconnect,
        .suspend        = cm109_usb_suspend,
        .resume         = cm109_usb_resume,
        .reset_resume   = cm109_usb_resume,
        .pre_reset      = cm109_usb_pre_reset,
        .post_reset     = cm109_usb_post_reset,
        .id_table       = cm109_usb_table,
        .supports_autosuspend = 1,
};

static int __init cm109_select_keymap(void)
{
        /* Load the phone keymap */
        if (!strcasecmp(phone, "kip1000")) {
                keymap = keymap_kip1000;
                printk(KERN_INFO KBUILD_MODNAME ": "
                        "Keymap for Komunikate KIP1000 phone loaded\n");
        } else if (!strcasecmp(phone, "gtalk")) {
                keymap = keymap_gtalk;
                printk(KERN_INFO KBUILD_MODNAME ": "
                        "Keymap for Genius G-talk phone loaded\n");
        } else if (!strcasecmp(phone, "usbph01")) {
                keymap = keymap_usbph01;
                printk(KERN_INFO KBUILD_MODNAME ": "
                        "Keymap for Allied-Telesis Corega USBPH01 phone loaded\n");
        } else if (!strcasecmp(phone, "atcom")) {
                keymap = keymap_atcom;
                printk(KERN_INFO KBUILD_MODNAME ": "
                        "Keymap for ATCom AU-100 phone loaded\n");
        } else {
                printk(KERN_ERR KBUILD_MODNAME ": "
                        "Unsupported phone: %s\n", phone);
                return -EINVAL;
        }

        return 0;
}

static int __init cm109_init(void)
{
        int err;

        err = cm109_select_keymap();
        if (err)
                return err;

        err = usb_register(&cm109_driver);
        if (err)
                return err;

        printk(KERN_INFO KBUILD_MODNAME ": "
                DRIVER_DESC ": " DRIVER_VERSION " (C) " DRIVER_AUTHOR "\n");

        return 0;
}

static void __exit cm109_exit(void)
{
        usb_deregister(&cm109_driver);
}

module_init(cm109_init);
module_exit(cm109_exit);

MODULE_DEVICE_TABLE(usb, cm109_usb_table);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");