// SPDX-License-Identifier: GPL-2.0+
/******************************************************************************
 *  speedtch.c  -  Alcatel SpeedTouch USB xDSL modem driver
 *
 *  Copyright (C) 2001, Alcatel
 *  Copyright (C) 2003, Duncan Sands
 *  Copyright (C) 2004, David Woodhouse
 *
 *  Based on "modem_run.c", copyright (C) 2001, Benoit Papillault
 ******************************************************************************/

#include <asm/page.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firmware.h>
#include <linux/hex.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/timer.h>
#include <linux/types.h>
#include <linux/usb/ch9.h>
#include <linux/workqueue.h>

#include "usbatm.h"

#define DRIVER_AUTHOR   "Johan Verrept, Duncan Sands <duncan.sands@free.fr>"
#define DRIVER_DESC     "Alcatel SpeedTouch USB driver"

static const char speedtch_driver_name[] = "speedtch";

#define CTRL_TIMEOUT 2000       /* milliseconds */
#define DATA_TIMEOUT 2000       /* milliseconds */

#define OFFSET_7        0               /* size 1 */
#define OFFSET_b        1               /* size 8 */
#define OFFSET_d        9               /* size 4 */
#define OFFSET_e        13              /* size 1 */
#define OFFSET_f        14              /* size 1 */

#define SIZE_7          1
#define SIZE_b          8
#define SIZE_d          4
#define SIZE_e          1
#define SIZE_f          1

#define MIN_POLL_DELAY          5000    /* milliseconds */
#define MAX_POLL_DELAY          60000   /* milliseconds */

#define RESUBMIT_DELAY          1000    /* milliseconds */

#define DEFAULT_BULK_ALTSETTING 1
#define DEFAULT_ISOC_ALTSETTING 3
#define DEFAULT_DL_512_FIRST    0
#define DEFAULT_ENABLE_ISOC     0
#define DEFAULT_SW_BUFFERING    0

static unsigned int altsetting = 0; /* zero means: use the default */
static bool dl_512_first = DEFAULT_DL_512_FIRST;
static bool enable_isoc = DEFAULT_ENABLE_ISOC;
static bool sw_buffering = DEFAULT_SW_BUFFERING;

#define DEFAULT_B_MAX_DSL       8128
#define DEFAULT_MODEM_MODE      11
#define MODEM_OPTION_LENGTH     16
static const unsigned char DEFAULT_MODEM_OPTION[MODEM_OPTION_LENGTH] = {
        0x10, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

static unsigned int BMaxDSL = DEFAULT_B_MAX_DSL;
static unsigned char ModemMode = DEFAULT_MODEM_MODE;
static unsigned char ModemOption[MODEM_OPTION_LENGTH];
static unsigned int num_ModemOption;

module_param(altsetting, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(altsetting,
                "Alternative setting for data interface (bulk_default: "
                __MODULE_STRING(DEFAULT_BULK_ALTSETTING) "; isoc_default: "
                __MODULE_STRING(DEFAULT_ISOC_ALTSETTING) ")");

module_param(dl_512_first, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(dl_512_first,
                 "Read 512 bytes before sending firmware (default: "
                 __MODULE_STRING(DEFAULT_DL_512_FIRST) ")");

module_param(enable_isoc, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(enable_isoc,
                "Use isochronous transfers if available (default: "
                __MODULE_STRING(DEFAULT_ENABLE_ISOC) ")");

module_param(sw_buffering, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(sw_buffering,
                 "Enable software buffering (default: "
                 __MODULE_STRING(DEFAULT_SW_BUFFERING) ")");

module_param(BMaxDSL, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(BMaxDSL,
                "default: " __MODULE_STRING(DEFAULT_B_MAX_DSL));

module_param(ModemMode, byte, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ModemMode,
                "default: " __MODULE_STRING(DEFAULT_MODEM_MODE));

module_param_array(ModemOption, byte, &num_ModemOption, S_IRUGO);
MODULE_PARM_DESC(ModemOption, "default: 0x10,0x00,0x00,0x00,0x20");

#define INTERFACE_DATA          1
#define ENDPOINT_INT            0x81
#define ENDPOINT_BULK_DATA      0x07
#define ENDPOINT_ISOC_DATA      0x07
#define ENDPOINT_FIRMWARE       0x05

struct speedtch_params {
        unsigned int altsetting;
        unsigned int BMaxDSL;
        unsigned char ModemMode;
        unsigned char ModemOption[MODEM_OPTION_LENGTH];
};

struct speedtch_instance_data {
        struct usbatm_data *usbatm;

        struct speedtch_params params; /* set in probe, constant afterwards */

        struct timer_list status_check_timer;
        struct work_struct status_check_work;

        unsigned char last_status;

        int poll_delay; /* milliseconds */

        struct timer_list resubmit_timer;
        struct urb *int_urb;
        unsigned char int_data[16];

        unsigned char scratch_buffer[16];
};

/***************
**  firmware  **
***************/

static void speedtch_set_swbuff(struct speedtch_instance_data *instance, int state)
{
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
        int ret;

        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x32, 0x40, state ? 0x01 : 0x00, 0x00, NULL, 0, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm,
                         "%sabling SW buffering: usb_control_msg returned %d\n",
                         state ? "En" : "Dis", ret);
        else
                usb_dbg(usbatm, "speedtch_set_swbuff: %sbled SW buffering\n", state ? "En" : "Dis");
}

static void speedtch_test_sequence(struct speedtch_instance_data *instance)
{
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
        unsigned char *buf = instance->scratch_buffer;
        int ret;

        /* URB 147 */
        buf[0] = 0x1c;
        buf[1] = 0x50;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x0b, 0x00, buf, 2, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URB147: %d\n", __func__, ret);

        /* URB 148 */
        buf[0] = 0x32;
        buf[1] = 0x00;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x02, 0x00, buf, 2, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URB148: %d\n", __func__, ret);

        /* URB 149 */
        buf[0] = 0x01;
        buf[1] = 0x00;
        buf[2] = 0x01;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x03, 0x00, buf, 3, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URB149: %d\n", __func__, ret);

        /* URB 150 */
        buf[0] = 0x01;
        buf[1] = 0x00;
        buf[2] = 0x01;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x04, 0x00, buf, 3, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URB150: %d\n", __func__, ret);

        /* Extra initialisation in recent drivers - gives higher speeds */

        /* URBext1 */
        buf[0] = instance->params.ModemMode;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x11, 0x00, buf, 1, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URBext1: %d\n", __func__, ret);

        /* URBext2 */
        /* This seems to be the one which actually triggers the higher sync
           rate -- it does require the new firmware too, although it works OK
           with older firmware */
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x14, 0x00,
                              instance->params.ModemOption,
                              MODEM_OPTION_LENGTH, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URBext2: %d\n", __func__, ret);

        /* URBext3 */
        buf[0] = instance->params.BMaxDSL & 0xff;
        buf[1] = instance->params.BMaxDSL >> 8;
        ret = usb_control_msg(usb_dev, usb_sndctrlpipe(usb_dev, 0),
                              0x01, 0x40, 0x12, 0x00, buf, 2, CTRL_TIMEOUT);
        if (ret < 0)
                usb_warn(usbatm, "%s failed on URBext3: %d\n", __func__, ret);
}

static int speedtch_upload_firmware(struct speedtch_instance_data *instance,
                                     const struct firmware *fw1,
                                     const struct firmware *fw2)
{
        unsigned char *buffer;
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
        int actual_length;
        int ret = 0;
        int offset;

        usb_dbg(usbatm, "%s entered\n", __func__);

        buffer = (unsigned char *)__get_free_page(GFP_KERNEL);
        if (!buffer) {
                ret = -ENOMEM;
                usb_dbg(usbatm, "%s: no memory for buffer!\n", __func__);
                goto out;
        }

        if (!usb_ifnum_to_if(usb_dev, 2)) {
                ret = -ENODEV;
                usb_dbg(usbatm, "%s: interface not found!\n", __func__);
                goto out_free;
        }

        /* URB 7 */
        if (dl_512_first) {     /* some modems need a read before writing the firmware */
                ret = usb_bulk_msg(usb_dev, usb_rcvbulkpipe(usb_dev, ENDPOINT_FIRMWARE),
                                   buffer, 0x200, &actual_length, 2000);

                if (ret < 0 && ret != -ETIMEDOUT)
                        usb_warn(usbatm, "%s: read BLOCK0 from modem failed (%d)!\n", __func__, ret);
                else
                        usb_dbg(usbatm, "%s: BLOCK0 downloaded (%d bytes)\n", __func__, ret);
        }

        /* URB 8 : both leds are static green */
        for (offset = 0; offset < fw1->size; offset += PAGE_SIZE) {
                int thislen = min_t(int, PAGE_SIZE, fw1->size - offset);
                memcpy(buffer, fw1->data + offset, thislen);

                ret = usb_bulk_msg(usb_dev, usb_sndbulkpipe(usb_dev, ENDPOINT_FIRMWARE),
                                   buffer, thislen, &actual_length, DATA_TIMEOUT);

                if (ret < 0) {
                        usb_err(usbatm, "%s: write BLOCK1 to modem failed (%d)!\n", __func__, ret);
                        goto out_free;
                }
                usb_dbg(usbatm, "%s: BLOCK1 uploaded (%zu bytes)\n", __func__, fw1->size);
        }

        /* USB led blinking green, ADSL led off */

        /* URB 11 */
        ret = usb_bulk_msg(usb_dev, usb_rcvbulkpipe(usb_dev, ENDPOINT_FIRMWARE),
                           buffer, 0x200, &actual_length, DATA_TIMEOUT);

        if (ret < 0) {
                usb_err(usbatm, "%s: read BLOCK2 from modem failed (%d)!\n", __func__, ret);
                goto out_free;
        }
        usb_dbg(usbatm, "%s: BLOCK2 downloaded (%d bytes)\n", __func__, actual_length);

        /* URBs 12 to 139 - USB led blinking green, ADSL led off */
        for (offset = 0; offset < fw2->size; offset += PAGE_SIZE) {
                int thislen = min_t(int, PAGE_SIZE, fw2->size - offset);
                memcpy(buffer, fw2->data + offset, thislen);

                ret = usb_bulk_msg(usb_dev, usb_sndbulkpipe(usb_dev, ENDPOINT_FIRMWARE),
                                   buffer, thislen, &actual_length, DATA_TIMEOUT);

                if (ret < 0) {
                        usb_err(usbatm, "%s: write BLOCK3 to modem failed (%d)!\n", __func__, ret);
                        goto out_free;
                }
        }
        usb_dbg(usbatm, "%s: BLOCK3 uploaded (%zu bytes)\n", __func__, fw2->size);

        /* USB led static green, ADSL led static red */

        /* URB 142 */
        ret = usb_bulk_msg(usb_dev, usb_rcvbulkpipe(usb_dev, ENDPOINT_FIRMWARE),
                           buffer, 0x200, &actual_length, DATA_TIMEOUT);

        if (ret < 0) {
                usb_err(usbatm, "%s: read BLOCK4 from modem failed (%d)!\n", __func__, ret);
                goto out_free;
        }

        /* success */
        usb_dbg(usbatm, "%s: BLOCK4 downloaded (%d bytes)\n", __func__, actual_length);

        /* Delay to allow firmware to start up. We can do this here
           because we're in our own kernel thread anyway. */
        msleep_interruptible(1000);

        if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, instance->params.altsetting)) < 0) {
                usb_err(usbatm, "%s: setting interface to %d failed (%d)!\n", __func__, instance->params.altsetting, ret);
                goto out_free;
        }

        /* Enable software buffering, if requested */
        if (sw_buffering)
                speedtch_set_swbuff(instance, 1);

        /* Magic spell; don't ask us what this does */
        speedtch_test_sequence(instance);

        ret = 0;

out_free:
        free_page((unsigned long)buffer);
out:
        return ret;
}

static int speedtch_find_firmware(struct usbatm_data *usbatm, struct usb_interface *intf,
                                  int phase, const struct firmware **fw_p)
{
        struct device *dev = &intf->dev;
        const u16 bcdDevice = le16_to_cpu(interface_to_usbdev(intf)->descriptor.bcdDevice);
        const u8 major_revision = bcdDevice >> 8;
        const u8 minor_revision = bcdDevice & 0xff;
        char buf[24];

        sprintf(buf, "speedtch-%d.bin.%x.%02x", phase, major_revision, minor_revision);
        usb_dbg(usbatm, "%s: looking for %s\n", __func__, buf);

        if (request_firmware(fw_p, buf, dev)) {
                sprintf(buf, "speedtch-%d.bin.%x", phase, major_revision);
                usb_dbg(usbatm, "%s: looking for %s\n", __func__, buf);

                if (request_firmware(fw_p, buf, dev)) {
                        sprintf(buf, "speedtch-%d.bin", phase);
                        usb_dbg(usbatm, "%s: looking for %s\n", __func__, buf);

                        if (request_firmware(fw_p, buf, dev)) {
                                usb_err(usbatm, "%s: no stage %d firmware found!\n", __func__, phase);
                                return -ENOENT;
                        }
                }
        }

        usb_info(usbatm, "found stage %d firmware %s\n", phase, buf);

        return 0;
}

static int speedtch_heavy_init(struct usbatm_data *usbatm, struct usb_interface *intf)
{
        const struct firmware *fw1, *fw2;
        struct speedtch_instance_data *instance = usbatm->driver_data;
        int ret;

        if ((ret = speedtch_find_firmware(usbatm, intf, 1, &fw1)) < 0)
                return ret;

        if ((ret = speedtch_find_firmware(usbatm, intf, 2, &fw2)) < 0) {
                release_firmware(fw1);
                return ret;
        }

        if ((ret = speedtch_upload_firmware(instance, fw1, fw2)) < 0)
                usb_err(usbatm, "%s: firmware upload failed (%d)!\n", __func__, ret);

        release_firmware(fw2);
        release_firmware(fw1);

        return ret;
}


/**********
**  ATM  **
**********/

static int speedtch_read_status(struct speedtch_instance_data *instance)
{
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
        unsigned char *buf = instance->scratch_buffer;
        int ret;

        memset(buf, 0, 16);

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x12, 0xc0, 0x07, 0x00, buf + OFFSET_7, SIZE_7,
                              CTRL_TIMEOUT);
        if (ret < 0) {
                atm_dbg(usbatm, "%s: MSG 7 failed\n", __func__);
                return ret;
        }

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x12, 0xc0, 0x0b, 0x00, buf + OFFSET_b, SIZE_b,
                              CTRL_TIMEOUT);
        if (ret < 0) {
                atm_dbg(usbatm, "%s: MSG B failed\n", __func__);
                return ret;
        }

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x12, 0xc0, 0x0d, 0x00, buf + OFFSET_d, SIZE_d,
                              CTRL_TIMEOUT);
        if (ret < 0) {
                atm_dbg(usbatm, "%s: MSG D failed\n", __func__);
                return ret;
        }

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x01, 0xc0, 0x0e, 0x00, buf + OFFSET_e, SIZE_e,
                              CTRL_TIMEOUT);
        if (ret < 0) {
                atm_dbg(usbatm, "%s: MSG E failed\n", __func__);
                return ret;
        }

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x01, 0xc0, 0x0f, 0x00, buf + OFFSET_f, SIZE_f,
                              CTRL_TIMEOUT);
        if (ret < 0) {
                atm_dbg(usbatm, "%s: MSG F failed\n", __func__);
                return ret;
        }

        return 0;
}

static int speedtch_start_synchro(struct speedtch_instance_data *instance)
{
        struct usbatm_data *usbatm = instance->usbatm;
        struct usb_device *usb_dev = usbatm->usb_dev;
        unsigned char *buf = instance->scratch_buffer;
        int ret;

        atm_dbg(usbatm, "%s entered\n", __func__);

        memset(buf, 0, 2);

        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x12, 0xc0, 0x04, 0x00,
                              buf, 2, CTRL_TIMEOUT);

        if (ret < 0)
                atm_warn(usbatm, "failed to start ADSL synchronisation: %d\n", ret);
        else
                atm_dbg(usbatm, "%s: modem prodded. %d bytes returned: %02x %02x\n",
                        __func__, ret, buf[0], buf[1]);

        return ret;
}

static void speedtch_check_status(struct work_struct *work)
{
        struct speedtch_instance_data *instance =
                container_of(work, struct speedtch_instance_data,
                             status_check_work);
        struct usbatm_data *usbatm = instance->usbatm;
        struct atm_dev *atm_dev = usbatm->atm_dev;
        unsigned char *buf = instance->scratch_buffer;
        int down_speed, up_speed, ret;
        unsigned char status;

#ifdef VERBOSE_DEBUG
        atm_dbg(usbatm, "%s entered\n", __func__);
#endif

        ret = speedtch_read_status(instance);
        if (ret < 0) {
                atm_warn(usbatm, "error %d fetching device status\n", ret);
                instance->poll_delay = min(2 * instance->poll_delay, MAX_POLL_DELAY);
                return;
        }

        instance->poll_delay = max(instance->poll_delay / 2, MIN_POLL_DELAY);

        status = buf[OFFSET_7];

        if ((status != instance->last_status) || !status) {
                atm_dbg(usbatm, "%s: line state 0x%02x\n", __func__, status);

                switch (status) {
                case 0:
                        atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
                        if (instance->last_status)
                                atm_info(usbatm, "ADSL line is down\n");
                        /* It may never resync again unless we ask it to... */
                        ret = speedtch_start_synchro(instance);
                        break;

                case 0x08:
                        atm_dev_signal_change(atm_dev, ATM_PHY_SIG_UNKNOWN);
                        atm_info(usbatm, "ADSL line is blocked?\n");
                        break;

                case 0x10:
                        atm_dev_signal_change(atm_dev, ATM_PHY_SIG_LOST);
                        atm_info(usbatm, "ADSL line is synchronising\n");
                        break;

                case 0x20:
                        down_speed = buf[OFFSET_b] | (buf[OFFSET_b + 1] << 8)
                                | (buf[OFFSET_b + 2] << 16) | (buf[OFFSET_b + 3] << 24);
                        up_speed = buf[OFFSET_b + 4] | (buf[OFFSET_b + 5] << 8)
                                | (buf[OFFSET_b + 6] << 16) | (buf[OFFSET_b + 7] << 24);

                        if (!(down_speed & 0x0000ffff) && !(up_speed & 0x0000ffff)) {
                                down_speed >>= 16;
                                up_speed >>= 16;
                        }

                        atm_dev->link_rate = down_speed * 1000 / 424;
                        atm_dev_signal_change(atm_dev, ATM_PHY_SIG_FOUND);

                        atm_info(usbatm,
                                 "ADSL line is up (%d kb/s down | %d kb/s up)\n",
                                 down_speed, up_speed);
                        break;

                default:
                        atm_dev_signal_change(atm_dev, ATM_PHY_SIG_UNKNOWN);
                        atm_info(usbatm, "unknown line state %02x\n", status);
                        break;
                }

                instance->last_status = status;
        }
}

static void speedtch_status_poll(struct timer_list *t)
{
        struct speedtch_instance_data *instance = timer_container_of(instance,
                                                                     t,
                                                                     status_check_timer);

        schedule_work(&instance->status_check_work);

        /* The following check is racy, but the race is harmless */
        if (instance->poll_delay < MAX_POLL_DELAY)
                mod_timer(&instance->status_check_timer, jiffies + msecs_to_jiffies(instance->poll_delay));
        else
                atm_warn(instance->usbatm, "Too many failures - disabling line status polling\n");
}

static void speedtch_resubmit_int(struct timer_list *t)
{
        struct speedtch_instance_data *instance = timer_container_of(instance,
                                                                     t,
                                                                     resubmit_timer);
        struct urb *int_urb = instance->int_urb;
        int ret;

        atm_dbg(instance->usbatm, "%s entered\n", __func__);

        if (int_urb) {
                ret = usb_submit_urb(int_urb, GFP_ATOMIC);
                if (!ret)
                        schedule_work(&instance->status_check_work);
                else {
                        atm_dbg(instance->usbatm, "%s: usb_submit_urb failed with result %d\n", __func__, ret);
                        mod_timer(&instance->resubmit_timer, jiffies + msecs_to_jiffies(RESUBMIT_DELAY));
                }
        }
}

static void speedtch_handle_int(struct urb *int_urb)
{
        struct speedtch_instance_data *instance = int_urb->context;
        struct usbatm_data *usbatm = instance->usbatm;
        unsigned int count = int_urb->actual_length;
        int status = int_urb->status;
        int ret;

        /* The magic interrupt for "up state" */
        static const unsigned char up_int[6]   = { 0xa1, 0x00, 0x01, 0x00, 0x00, 0x00 };
        /* The magic interrupt for "down state" */
        static const unsigned char down_int[6] = { 0xa1, 0x00, 0x00, 0x00, 0x00, 0x00 };

        atm_dbg(usbatm, "%s entered\n", __func__);

        if (status < 0) {
                atm_dbg(usbatm, "%s: nonzero urb status %d!\n", __func__, status);
                goto fail;
        }

        if ((count == 6) && !memcmp(up_int, instance->int_data, 6)) {
                timer_delete(&instance->status_check_timer);
                atm_info(usbatm, "DSL line goes up\n");
        } else if ((count == 6) && !memcmp(down_int, instance->int_data, 6)) {
                atm_info(usbatm, "DSL line goes down\n");
        } else {
                int i;

                atm_dbg(usbatm, "%s: unknown interrupt packet of length %d:", __func__, count);
                for (i = 0; i < count; i++)
                        printk(" %02x", instance->int_data[i]);
                printk("\n");
                goto fail;
        }

        int_urb = instance->int_urb;
        if (int_urb) {
                ret = usb_submit_urb(int_urb, GFP_ATOMIC);
                schedule_work(&instance->status_check_work);
                if (ret < 0) {
                        atm_dbg(usbatm, "%s: usb_submit_urb failed with result %d\n", __func__, ret);
                        goto fail;
                }
        }

        return;

fail:
        int_urb = instance->int_urb;
        if (int_urb)
                mod_timer(&instance->resubmit_timer, jiffies + msecs_to_jiffies(RESUBMIT_DELAY));
}

static int speedtch_atm_start(struct usbatm_data *usbatm, struct atm_dev *atm_dev)
{
        struct usb_device *usb_dev = usbatm->usb_dev;
        struct speedtch_instance_data *instance = usbatm->driver_data;
        int i, ret;
        unsigned char mac_str[13];

        atm_dbg(usbatm, "%s entered\n", __func__);

        /* Set MAC address, it is stored in the serial number */
        memset(atm_dev->esi, 0, sizeof(atm_dev->esi));
        if (usb_string(usb_dev, usb_dev->descriptor.iSerialNumber, mac_str, sizeof(mac_str)) == 12) {
                for (i = 0; i < 6; i++)
                        atm_dev->esi[i] = (hex_to_bin(mac_str[i * 2]) << 4) +
                                hex_to_bin(mac_str[i * 2 + 1]);
        }

        /* Start modem synchronisation */
        ret = speedtch_start_synchro(instance);

        /* Set up interrupt endpoint */
        if (instance->int_urb) {
                ret = usb_submit_urb(instance->int_urb, GFP_KERNEL);
                if (ret < 0) {
                        /* Doesn't matter; we'll poll anyway */
                        atm_dbg(usbatm, "%s: submission of interrupt URB failed (%d)!\n", __func__, ret);
                        usb_free_urb(instance->int_urb);
                        instance->int_urb = NULL;
                }
        }

        /* Start status polling */
        mod_timer(&instance->status_check_timer, jiffies + msecs_to_jiffies(1000));

        return 0;
}

static void speedtch_atm_stop(struct usbatm_data *usbatm, struct atm_dev *atm_dev)
{
        struct speedtch_instance_data *instance = usbatm->driver_data;
        struct urb *int_urb = instance->int_urb;

        atm_dbg(usbatm, "%s entered\n", __func__);

        timer_delete_sync(&instance->status_check_timer);

        /*
         * Since resubmit_timer and int_urb can schedule themselves and
         * each other, shutting them down correctly takes some care
         */
        instance->int_urb = NULL; /* signal shutdown */
        mb();
        usb_kill_urb(int_urb);
        timer_delete_sync(&instance->resubmit_timer);
        /*
         * At this point, speedtch_handle_int and speedtch_resubmit_int
         * can run or be running, but instance->int_urb == NULL means that
         * they will not reschedule
         */
        usb_kill_urb(int_urb);
        timer_delete_sync(&instance->resubmit_timer);
        usb_free_urb(int_urb);

        flush_work(&instance->status_check_work);
}

static int speedtch_pre_reset(struct usb_interface *intf)
{
        return 0;
}

static int speedtch_post_reset(struct usb_interface *intf)
{
        return 0;
}


/**********
**  USB  **
**********/

static const struct usb_device_id speedtch_usb_ids[] = {
        {USB_DEVICE(0x06b9, 0x4061)},
        {}
};

MODULE_DEVICE_TABLE(usb, speedtch_usb_ids);

static int speedtch_usb_probe(struct usb_interface *, const struct usb_device_id *);

static struct usb_driver speedtch_usb_driver = {
        .name           = speedtch_driver_name,
        .probe          = speedtch_usb_probe,
        .disconnect     = usbatm_usb_disconnect,
        .pre_reset      = speedtch_pre_reset,
        .post_reset     = speedtch_post_reset,
        .id_table       = speedtch_usb_ids
};

static void speedtch_release_interfaces(struct usb_device *usb_dev,
                                        int num_interfaces)
{
        struct usb_interface *cur_intf;
        int i;

        for (i = 0; i < num_interfaces; i++) {
                cur_intf = usb_ifnum_to_if(usb_dev, i);
                if (cur_intf) {
                        usb_set_intfdata(cur_intf, NULL);
                        usb_driver_release_interface(&speedtch_usb_driver, cur_intf);
                }
        }
}

static int speedtch_bind(struct usbatm_data *usbatm,
                         struct usb_interface *intf,
                         const struct usb_device_id *id)
{
        struct usb_device *usb_dev = interface_to_usbdev(intf);
        struct usb_interface *cur_intf, *data_intf;
        struct speedtch_instance_data *instance;
        int ifnum = intf->altsetting->desc.bInterfaceNumber;
        int num_interfaces = usb_dev->actconfig->desc.bNumInterfaces;
        int i, ret;
        int use_isoc;

        usb_dbg(usbatm, "%s entered\n", __func__);

        /* sanity checks */

        if (usb_dev->descriptor.bDeviceClass != USB_CLASS_VENDOR_SPEC) {
                usb_err(usbatm, "%s: wrong device class %d\n", __func__, usb_dev->descriptor.bDeviceClass);
                return -ENODEV;
        }

        data_intf = usb_ifnum_to_if(usb_dev, INTERFACE_DATA);
        if (!data_intf) {
                usb_err(usbatm, "%s: data interface not found!\n", __func__);
                return -ENODEV;
        }

        /* claim all interfaces */

        for (i = 0; i < num_interfaces; i++) {
                cur_intf = usb_ifnum_to_if(usb_dev, i);

                if ((i != ifnum) && cur_intf) {
                        ret = usb_driver_claim_interface(&speedtch_usb_driver, cur_intf, usbatm);

                        if (ret < 0) {
                                usb_err(usbatm, "%s: failed to claim interface %2d (%d)!\n", __func__, i, ret);
                                speedtch_release_interfaces(usb_dev, i);
                                return ret;
                        }
                }
        }

        instance = kzalloc_obj(*instance);

        if (!instance) {
                ret = -ENOMEM;
                goto fail_release;
        }

        instance->usbatm = usbatm;

        /* module parameters may change at any moment, so take a snapshot */
        instance->params.altsetting = altsetting;
        instance->params.BMaxDSL = BMaxDSL;
        instance->params.ModemMode = ModemMode;
        memcpy(instance->params.ModemOption, DEFAULT_MODEM_OPTION, MODEM_OPTION_LENGTH);
        memcpy(instance->params.ModemOption, ModemOption, num_ModemOption);
        use_isoc = enable_isoc;

        if (instance->params.altsetting)
                if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, instance->params.altsetting)) < 0) {
                        usb_err(usbatm, "%s: setting interface to %2d failed (%d)!\n", __func__, instance->params.altsetting, ret);
                        instance->params.altsetting = 0; /* fall back to default */
                }

        if (!instance->params.altsetting && use_isoc)
                if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, DEFAULT_ISOC_ALTSETTING)) < 0) {
                        usb_dbg(usbatm, "%s: setting interface to %2d failed (%d)!\n", __func__, DEFAULT_ISOC_ALTSETTING, ret);
                        use_isoc = 0; /* fall back to bulk */
                }

        if (use_isoc) {
                const struct usb_host_interface *desc = data_intf->cur_altsetting;
                const __u8 target_address = USB_DIR_IN | usbatm->driver->isoc_in;

                use_isoc = 0; /* fall back to bulk if endpoint not found */

                for (i = 0; i < desc->desc.bNumEndpoints; i++) {
                        const struct usb_endpoint_descriptor *endpoint_desc = &desc->endpoint[i].desc;

                        if ((endpoint_desc->bEndpointAddress == target_address)) {
                                use_isoc =
                                        usb_endpoint_xfer_isoc(endpoint_desc);
                                break;
                        }
                }

                if (!use_isoc)
                        usb_info(usbatm, "isochronous transfer not supported - using bulk\n");
        }

        if (!use_isoc && !instance->params.altsetting)
                if ((ret = usb_set_interface(usb_dev, INTERFACE_DATA, DEFAULT_BULK_ALTSETTING)) < 0) {
                        usb_err(usbatm, "%s: setting interface to %2d failed (%d)!\n", __func__, DEFAULT_BULK_ALTSETTING, ret);
                        goto fail_free;
                }

        if (!instance->params.altsetting)
                instance->params.altsetting = use_isoc ? DEFAULT_ISOC_ALTSETTING : DEFAULT_BULK_ALTSETTING;

        usbatm->flags |= (use_isoc ? UDSL_USE_ISOC : 0);

        INIT_WORK(&instance->status_check_work, speedtch_check_status);
        timer_setup(&instance->status_check_timer, speedtch_status_poll, 0);
        instance->last_status = 0xff;
        instance->poll_delay = MIN_POLL_DELAY;

        timer_setup(&instance->resubmit_timer, speedtch_resubmit_int, 0);

        instance->int_urb = usb_alloc_urb(0, GFP_KERNEL);

        if (instance->int_urb)
                usb_fill_int_urb(instance->int_urb, usb_dev,
                                 usb_rcvintpipe(usb_dev, ENDPOINT_INT),
                                 instance->int_data, sizeof(instance->int_data),
                                 speedtch_handle_int, instance, 16);
        else
                usb_dbg(usbatm, "%s: no memory for interrupt urb!\n", __func__);

        /* check whether the modem already seems to be alive */
        ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
                              0x12, 0xc0, 0x07, 0x00,
                              instance->scratch_buffer + OFFSET_7, SIZE_7, 500);

        usbatm->flags |= (ret == SIZE_7 ? UDSL_SKIP_HEAVY_INIT : 0);

        usb_dbg(usbatm, "%s: firmware %s loaded\n", __func__, usbatm->flags & UDSL_SKIP_HEAVY_INIT ? "already" : "not");

        if (!(usbatm->flags & UDSL_SKIP_HEAVY_INIT))
                if ((ret = usb_reset_device(usb_dev)) < 0) {
                        usb_err(usbatm, "%s: device reset failed (%d)!\n", __func__, ret);
                        goto fail_free;
                }

        usbatm->driver_data = instance;

        return 0;

fail_free:
        usb_free_urb(instance->int_urb);
        kfree(instance);
fail_release:
        speedtch_release_interfaces(usb_dev, num_interfaces);
        return ret;
}

static void speedtch_unbind(struct usbatm_data *usbatm, struct usb_interface *intf)
{
        struct usb_device *usb_dev = interface_to_usbdev(intf);
        struct speedtch_instance_data *instance = usbatm->driver_data;

        usb_dbg(usbatm, "%s entered\n", __func__);

        speedtch_release_interfaces(usb_dev, usb_dev->actconfig->desc.bNumInterfaces);
        usb_free_urb(instance->int_urb);
        kfree(instance);
}


/***********
**  init  **
***********/

static struct usbatm_driver speedtch_usbatm_driver = {
        .driver_name    = speedtch_driver_name,
        .bind           = speedtch_bind,
        .heavy_init     = speedtch_heavy_init,
        .unbind         = speedtch_unbind,
        .atm_start      = speedtch_atm_start,
        .atm_stop       = speedtch_atm_stop,
        .bulk_in        = ENDPOINT_BULK_DATA,
        .bulk_out       = ENDPOINT_BULK_DATA,
        .isoc_in        = ENDPOINT_ISOC_DATA
};

static int speedtch_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
{
        return usbatm_usb_probe(intf, id, &speedtch_usbatm_driver);
}

module_usb_driver(speedtch_usb_driver);

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