omninet.c

Go to the documentation of this file.

/*
 * USB ZyXEL omni.net LCD PLUS driver
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version
 *  2 as published by the Free Software Foundation.
 *
 * See Documentation/usb/usb-serial.txt for more information on using this
 * driver
 *
 * Please report both successes and troubles to the author at [email protected]
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v1.1"
#define DRIVER_AUTHOR "Alessandro Zummo"
#define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"

#define ZYXEL_VENDOR_ID     0x0586
#define ZYXEL_OMNINET_ID    0x1000
/* This one seems to be a re-branded ZyXEL device */
#define BT_IGNITIONPRO_ID   0x2000

/* function prototypes */
static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
static void omninet_close(struct usb_serial_port *port);
static void omninet_read_bulk_callback(struct urb *urb);
static void omninet_write_bulk_callback(struct urb *urb);
static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
                const unsigned char *buf, int count);
static int  omninet_write_room(struct tty_struct *tty);
static void omninet_disconnect(struct usb_serial *serial);
static int omninet_port_probe(struct usb_serial_port *port);
static int omninet_port_remove(struct usb_serial_port *port);

static const struct usb_device_id id_table[] = {
    { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
    { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
    { }                     /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);

static struct usb_serial_driver zyxel_omninet_device = {
    .driver = {
        .owner =    THIS_MODULE,
        .name =     "omninet",
    },
    .description =      "ZyXEL - omni.net lcd plus usb",
    .id_table =     id_table,
    .num_ports =        1,
    .port_probe =       omninet_port_probe,
    .port_remove =      omninet_port_remove,
    .open =         omninet_open,
    .close =        omninet_close,
    .write =        omninet_write,
    .write_room =       omninet_write_room,
    .read_bulk_callback =   omninet_read_bulk_callback,
    .write_bulk_callback =  omninet_write_bulk_callback,
    .disconnect =       omninet_disconnect,
};

static struct usb_serial_driver * const serial_drivers[] = {
    &zyxel_omninet_device, NULL
};


/* The protocol.
 *
 * The omni.net always exchange 64 bytes of data with the host. The first
 * four bytes are the control header, you can see it in the above structure.
 *
 * oh_seq is a sequence number. Don't know if/how it's used.
 * oh_len is the length of the data bytes in the packet.
 * oh_xxx Bit-mapped, related to handshaking and status info.
 *  I normally set it to 0x03 in trasmitted frames.
 *  7: Active when the TA is in a CONNECTed state.
 *  6: unknown
 *  5: handshaking, unknown
 *  4: handshaking, unknown
 *  3: unknown, usually 0
 *  2: unknown, usually 0
 *  1: handshaking, unknown, usually set to 1 in trasmitted frames
 *  0: handshaking, unknown, usually set to 1 in trasmitted frames
 * oh_pad Probably a pad byte.
 *
 * After the header you will find data bytes if oh_len was greater than zero.
 *
 */

struct omninet_header {
    __u8    oh_seq;
    __u8    oh_len;
    __u8    oh_xxx;
    __u8    oh_pad;
};

struct omninet_data {
    __u8    od_outseq;  /* Sequence number for bulk_out URBs */
};

static int omninet_port_probe(struct usb_serial_port *port)
{
    struct omninet_data *od;

    od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
    if (!od)
        return -ENOMEM;

    usb_set_serial_port_data(port, od);

    return 0;
}

static int omninet_port_remove(struct usb_serial_port *port)
{
    struct omninet_data *od;

    od = usb_get_serial_port_data(port);
    kfree(od);

    return 0;
}

static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
{
    struct usb_serial   *serial = port->serial;
    struct usb_serial_port  *wport;
    int         result = 0;

    wport = serial->port[1];
    tty_port_tty_set(&wport->port, tty);

    /* Start reading from the device */
    result = usb_submit_urb(port->read_urb, GFP_KERNEL);
    if (result)
        dev_err(&port->dev,
            "%s - failed submitting read urb, error %d\n",
            __func__, result);
    return result;
}

static void omninet_close(struct usb_serial_port *port)
{
    usb_kill_urb(port->read_urb);
}


#define OMNINET_DATAOFFSET  0x04
#define OMNINET_HEADERLEN   sizeof(struct omninet_header)
#define OMNINET_BULKOUTSIZE     (64 - OMNINET_HEADERLEN)

static void omninet_read_bulk_callback(struct urb *urb)
{
    struct usb_serial_port  *port   = urb->context;
    unsigned char       *data   = urb->transfer_buffer;
    struct omninet_header   *header = (struct omninet_header *) &data[0];
    int status = urb->status;
    int result;

    if (status) {
        dev_dbg(&port->dev, "%s - nonzero read bulk status received: %d\n",
            __func__, status);
        return;
    }

    if (urb->actual_length && header->oh_len) {
        struct tty_struct *tty = tty_port_tty_get(&port->port);
        if (tty) {
            tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
                            header->oh_len);
            tty_flip_buffer_push(tty);
            tty_kref_put(tty);
        }
    }

    /* Continue trying to always read  */
    result = usb_submit_urb(urb, GFP_ATOMIC);
    if (result)
        dev_err(&port->dev,
            "%s - failed resubmitting read urb, error %d\n",
            __func__, result);
}

static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
                    const unsigned char *buf, int count)
{
    struct usb_serial *serial = port->serial;
    struct usb_serial_port *wport = serial->port[1];

    struct omninet_data *od = usb_get_serial_port_data(port);
    struct omninet_header *header = (struct omninet_header *)
                    wport->write_urb->transfer_buffer;

    int         result;

    if (count == 0) {
        dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
        return 0;
    }

    if (!test_and_clear_bit(0, &port->write_urbs_free)) {
        dev_dbg(&port->dev, "%s - already writing\n", __func__);
        return 0;
    }

    count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;

    memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
                                buf, count);

    usb_serial_debug_data(&port->dev, __func__, count,
                  wport->write_urb->transfer_buffer);

    header->oh_seq  = od->od_outseq++;
    header->oh_len  = count;
    header->oh_xxx  = 0x03;
    header->oh_pad  = 0x00;

    /* send the data out the bulk port, always 64 bytes */
    wport->write_urb->transfer_buffer_length = 64;

    result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
    if (result) {
        set_bit(0, &wport->write_urbs_free);
        dev_err_console(port,
            "%s - failed submitting write urb, error %d\n",
            __func__, result);
    } else
        result = count;

    return result;
}


static int omninet_write_room(struct tty_struct *tty)
{
    struct usb_serial_port *port = tty->driver_data;
    struct usb_serial   *serial = port->serial;
    struct usb_serial_port  *wport  = serial->port[1];

    int room = 0; /* Default: no room */

    if (test_bit(0, &wport->write_urbs_free))
        room = wport->bulk_out_size - OMNINET_HEADERLEN;

    dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);

    return room;
}

static void omninet_write_bulk_callback(struct urb *urb)
{
/*  struct omninet_header   *header = (struct omninet_header  *)
                        urb->transfer_buffer; */
    struct usb_serial_port  *port   =  urb->context;
    int status = urb->status;

    set_bit(0, &port->write_urbs_free);
    if (status) {
        dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
            __func__, status);
        return;
    }

    usb_serial_port_softint(port);
}


static void omninet_disconnect(struct usb_serial *serial)
{
    struct usb_serial_port *wport = serial->port[1];

    usb_kill_urb(wport->write_urb);
}

module_usb_serial_driver(serial_drivers, id_table);

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