xusbatm.c

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/******************************************************************************
 *  xusbatm.c - dumb usbatm-based driver for modems initialized in userspace
 *
 *  Copyright (C) 2005 Duncan Sands, Roman Kagan (rkagan % mail ! ru)
 *
 *  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., 59
 *  Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 ******************************************************************************/

#include <linux/module.h>
#include <linux/etherdevice.h>      /* for eth_random_addr() */

#include "usbatm.h"


#define XUSBATM_DRIVERS_MAX 8

#define XUSBATM_PARM(name, type, parmtype, desc) \
    static type name[XUSBATM_DRIVERS_MAX]; \
    static unsigned int num_##name; \
    module_param_array(name, parmtype, &num_##name, 0444); \
    MODULE_PARM_DESC(name, desc)

XUSBATM_PARM(vendor, unsigned short, ushort, "USB device vendor");
XUSBATM_PARM(product, unsigned short, ushort, "USB device product");

XUSBATM_PARM(rx_endpoint, unsigned char, byte, "rx endpoint number");
XUSBATM_PARM(tx_endpoint, unsigned char, byte, "tx endpoint number");
XUSBATM_PARM(rx_padding, unsigned char, byte, "rx padding (default 0)");
XUSBATM_PARM(tx_padding, unsigned char, byte, "tx padding (default 0)");
XUSBATM_PARM(rx_altsetting, unsigned char, byte, "rx altsetting (default 0)");
XUSBATM_PARM(tx_altsetting, unsigned char, byte, "rx altsetting (default 0)");

static const char xusbatm_driver_name[] = "xusbatm";

static struct usbatm_driver xusbatm_drivers[XUSBATM_DRIVERS_MAX];
static struct usb_device_id xusbatm_usb_ids[XUSBATM_DRIVERS_MAX + 1];
static struct usb_driver xusbatm_usb_driver;

static struct usb_interface *xusbatm_find_intf(struct usb_device *usb_dev, int altsetting, u8 ep)
{
    struct usb_host_interface *alt;
    struct usb_interface *intf;
    int i, j;

    for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++)
        if ((intf = usb_dev->actconfig->interface[i]) && (alt = usb_altnum_to_altsetting(intf, altsetting)))
            for (j = 0; j < alt->desc.bNumEndpoints; j++)
                if (alt->endpoint[j].desc.bEndpointAddress == ep)
                    return intf;
    return NULL;
}

static int xusbatm_capture_intf(struct usbatm_data *usbatm, struct usb_device *usb_dev,
        struct usb_interface *intf, int altsetting, int claim)
{
    int ifnum = intf->altsetting->desc.bInterfaceNumber;
    int ret;

    if (claim && (ret = usb_driver_claim_interface(&xusbatm_usb_driver, intf, usbatm))) {
        usb_err(usbatm, "%s: failed to claim interface %2d (%d)!\n", __func__, ifnum, ret);
        return ret;
    }
    if ((ret = usb_set_interface(usb_dev, ifnum, altsetting))) {
        usb_err(usbatm, "%s: altsetting %2d for interface %2d failed (%d)!\n", __func__, altsetting, ifnum, ret);
        return ret;
    }
    return 0;
}

static void xusbatm_release_intf(struct usb_device *usb_dev, struct usb_interface *intf, int claimed)
{
    if (claimed) {
        usb_set_intfdata(intf, NULL);
        usb_driver_release_interface(&xusbatm_usb_driver, intf);
    }
}

static int xusbatm_bind(struct usbatm_data *usbatm,
            struct usb_interface *intf, const struct usb_device_id *id)
{
    struct usb_device *usb_dev = interface_to_usbdev(intf);
    int drv_ix = id - xusbatm_usb_ids;
    int rx_alt = rx_altsetting[drv_ix];
    int tx_alt = tx_altsetting[drv_ix];
    struct usb_interface *rx_intf = xusbatm_find_intf(usb_dev, rx_alt, rx_endpoint[drv_ix]);
    struct usb_interface *tx_intf = xusbatm_find_intf(usb_dev, tx_alt, tx_endpoint[drv_ix]);
    int ret;

    usb_dbg(usbatm, "%s: binding driver %d: vendor %04x product %04x"
        " rx: ep %02x padd %d alt %2d tx: ep %02x padd %d alt %2d\n",
        __func__, drv_ix, vendor[drv_ix], product[drv_ix],
        rx_endpoint[drv_ix], rx_padding[drv_ix], rx_alt,
        tx_endpoint[drv_ix], tx_padding[drv_ix], tx_alt);

    if (!rx_intf || !tx_intf) {
        if (!rx_intf)
            usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
                __func__, rx_endpoint[drv_ix], rx_alt);
        if (!tx_intf)
            usb_dbg(usbatm, "%s: no interface contains endpoint %02x in altsetting %2d\n",
                __func__, tx_endpoint[drv_ix], tx_alt);
        return -ENODEV;
    }

    if ((rx_intf != intf) && (tx_intf != intf))
        return -ENODEV;

    if ((rx_intf == tx_intf) && (rx_alt != tx_alt)) {
        usb_err(usbatm, "%s: altsettings clash on interface %2d (%2d vs %2d)!\n", __func__,
                rx_intf->altsetting->desc.bInterfaceNumber, rx_alt, tx_alt);
        return -EINVAL;
    }

    usb_dbg(usbatm, "%s: rx If#=%2d; tx If#=%2d\n", __func__,
            rx_intf->altsetting->desc.bInterfaceNumber,
            tx_intf->altsetting->desc.bInterfaceNumber);

    if ((ret = xusbatm_capture_intf(usbatm, usb_dev, rx_intf, rx_alt, rx_intf != intf)))
        return ret;

    if ((tx_intf != rx_intf) && (ret = xusbatm_capture_intf(usbatm, usb_dev, tx_intf, tx_alt, tx_intf != intf))) {
        xusbatm_release_intf(usb_dev, rx_intf, rx_intf != intf);
        return ret;
    }

    return 0;
}

static void xusbatm_unbind(struct usbatm_data *usbatm,
               struct usb_interface *intf)
{
    struct usb_device *usb_dev = interface_to_usbdev(intf);
    int i;

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

    for (i = 0; i < usb_dev->actconfig->desc.bNumInterfaces; i++) {
        struct usb_interface *cur_intf = usb_dev->actconfig->interface[i];

        if (cur_intf && (usb_get_intfdata(cur_intf) == usbatm)) {
            usb_set_intfdata(cur_intf, NULL);
            usb_driver_release_interface(&xusbatm_usb_driver, cur_intf);
        }
    }
}

static int xusbatm_atm_start(struct usbatm_data *usbatm,
                 struct atm_dev *atm_dev)
{
    atm_dbg(usbatm, "%s entered\n", __func__);

    /* use random MAC as we've no way to get it from the device */
    eth_random_addr(atm_dev->esi);

    return 0;
}


static int xusbatm_usb_probe(struct usb_interface *intf,
                 const struct usb_device_id *id)
{
    return usbatm_usb_probe(intf, id,
                xusbatm_drivers + (id - xusbatm_usb_ids));
}

static struct usb_driver xusbatm_usb_driver = {
    .name       = xusbatm_driver_name,
    .probe      = xusbatm_usb_probe,
    .disconnect = usbatm_usb_disconnect,
    .id_table   = xusbatm_usb_ids
};

static int __init xusbatm_init(void)
{
    int i;

    if (!num_vendor ||
        num_vendor != num_product ||
        num_vendor != num_rx_endpoint ||
        num_vendor != num_tx_endpoint) {
        printk(KERN_WARNING "xusbatm: malformed module parameters\n");
        return -EINVAL;
    }

    for (i = 0; i < num_vendor; i++) {
        rx_endpoint[i] |= USB_DIR_IN;
        tx_endpoint[i] &= USB_ENDPOINT_NUMBER_MASK;

        xusbatm_usb_ids[i].match_flags  = USB_DEVICE_ID_MATCH_DEVICE;
        xusbatm_usb_ids[i].idVendor = vendor[i];
        xusbatm_usb_ids[i].idProduct    = product[i];

        xusbatm_drivers[i].driver_name  = xusbatm_driver_name;
        xusbatm_drivers[i].bind     = xusbatm_bind;
        xusbatm_drivers[i].unbind   = xusbatm_unbind;
        xusbatm_drivers[i].atm_start    = xusbatm_atm_start;
        xusbatm_drivers[i].bulk_in  = rx_endpoint[i];
        xusbatm_drivers[i].bulk_out = tx_endpoint[i];
        xusbatm_drivers[i].rx_padding   = rx_padding[i];
        xusbatm_drivers[i].tx_padding   = tx_padding[i];
    }

    return usb_register(&xusbatm_usb_driver);
}
module_init(xusbatm_init);

static void __exit xusbatm_exit(void)
{
    usb_deregister(&xusbatm_usb_driver);
}
module_exit(xusbatm_exit);

MODULE_AUTHOR("Roman Kagan, Duncan Sands");
MODULE_DESCRIPTION("Driver for USB ADSL modems initialized in userspace");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.1");