drivers/usb/serial/omninet.c

   1 /*
   2  * USB ZyXEL omni.net LCD PLUS driver
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License version
   6  *      2 as published by the Free Software Foundation.
   7  *
   8  * See Documentation/usb/usb-serial.txt for more information on using this
   9  * driver
  10  *
  11  * Please report both successes and troubles to the author at omninet@kroah.com
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/tty.h>
  19 #include <linux/tty_driver.h>
  20 #include <linux/tty_flip.h>
  21 #include <linux/module.h>
  22 #include <linux/uaccess.h>
  23 #include <linux/usb.h>
  24 #include <linux/usb/serial.h>
  25
  26 /*
  27  * Version Information
  28  */
  29 #define DRIVER_VERSION "v1.1"
  30 #define DRIVER_AUTHOR "Alessandro Zummo"
  31 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
  32
  33 #define ZYXEL_VENDOR_ID         0x0586
  34 #define ZYXEL_OMNINET_ID        0x1000
  35 /* This one seems to be a re-branded ZyXEL device */
  36 #define BT_IGNITIONPRO_ID       0x2000
  37
  38 /* function prototypes */
  39 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
  40 static void omninet_close(struct usb_serial_port *port);
  41 static void omninet_read_bulk_callback(struct urb *urb);
  42 static void omninet_write_bulk_callback(struct urb *urb);
  43 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  44                                 const unsigned char *buf, int count);
  45 static int  omninet_write_room(struct tty_struct *tty);
  46 static void omninet_disconnect(struct usb_serial *serial);
  47 static int omninet_port_probe(struct usb_serial_port *port);
  48 static int omninet_port_remove(struct usb_serial_port *port);
  49
  50 static const struct usb_device_id id_table[] = {
  51         { USB_DEVICE(ZYXEL_VENDOR_ID, ZYXEL_OMNINET_ID) },
  52         { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
  53         { }                                             /* Terminating entry */
  54 };
  55 MODULE_DEVICE_TABLE(usb, id_table);
  56
  57 static struct usb_serial_driver zyxel_omninet_device = {
  58         .driver = {
  59                 .owner =        THIS_MODULE,
  60                 .name =         "omninet",
  61         },
  62         .description =          "ZyXEL - omni.net lcd plus usb",
  63         .id_table =             id_table,
  64         .num_ports =            1,
  65         .port_probe =           omninet_port_probe,
  66         .port_remove =          omninet_port_remove,
  67         .open =                 omninet_open,
  68         .close =                omninet_close,
  69         .write =                omninet_write,
  70         .write_room =           omninet_write_room,
  71         .read_bulk_callback =   omninet_read_bulk_callback,
  72         .write_bulk_callback =  omninet_write_bulk_callback,
  73         .disconnect =           omninet_disconnect,
  74 };
  75
  76 static struct usb_serial_driver * const serial_drivers[] = {
  77         &zyxel_omninet_device, NULL
  78 };
  79
  80
  81 /* The protocol.
  82  *
  83  * The omni.net always exchange 64 bytes of data with the host. The first
  84  * four bytes are the control header, you can see it in the above structure.
  85  *
  86  * oh_seq is a sequence number. Don't know if/how it's used.
  87  * oh_len is the length of the data bytes in the packet.
  88  * oh_xxx Bit-mapped, related to handshaking and status info.
  89  *      I normally set it to 0x03 in trasmitted frames.
  90  *      7: Active when the TA is in a CONNECTed state.
  91  *      6: unknown
  92  *      5: handshaking, unknown
  93  *      4: handshaking, unknown
  94  *      3: unknown, usually 0
  95  *      2: unknown, usually 0
  96  *      1: handshaking, unknown, usually set to 1 in trasmitted frames
  97  *      0: handshaking, unknown, usually set to 1 in trasmitted frames
  98  * oh_pad Probably a pad byte.
  99  *
 100  * After the header you will find data bytes if oh_len was greater than zero.
 101  *
 102  */
 103
 104 struct omninet_header {
 105         __u8    oh_seq;
 106         __u8    oh_len;
 107         __u8    oh_xxx;
 108         __u8    oh_pad;
 109 };
 110
 111 struct omninet_data {
 112         __u8    od_outseq;      /* Sequence number for bulk_out URBs */
 113 };
 114
 115 static int omninet_port_probe(struct usb_serial_port *port)
 116 {
 117         struct omninet_data *od;
 118
 119         od = kmalloc(sizeof(struct omninet_data), GFP_KERNEL);
 120         if (!od)
 121                 return -ENOMEM;
 122
 123         usb_set_serial_port_data(port, od);
 124
 125         return 0;
 126 }
 127
 128 static int omninet_port_remove(struct usb_serial_port *port)
 129 {
 130         struct omninet_data *od;
 131
 132         od = usb_get_serial_port_data(port);
 133         kfree(od);
 134
 135         return 0;
 136 }
 137
 138 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
 139 {
 140         struct usb_serial       *serial = port->serial;
 141         struct usb_serial_port  *wport;
 142         int                     result = 0;
 143
 144         wport = serial->port[1];
 145         tty_port_tty_set(&wport->port, tty);
 146
 147         /* Start reading from the device */
 148         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 149         if (result)
 150                 dev_err(&port->dev,
 151                         "%s - failed submitting read urb, error %d\n",
 152                         __func__, result);
 153         return result;
 154 }
 155
 156 static void omninet_close(struct usb_serial_port *port)
 157 {
 158         usb_kill_urb(port->read_urb);
 159 }
 160
 161
 162 #define OMNINET_DATAOFFSET      0x04
 163 #define OMNINET_HEADERLEN       sizeof(struct omninet_header)
 164 #define OMNINET_BULKOUTSIZE     (64 - OMNINET_HEADERLEN)
 165
 166 static void omninet_read_bulk_callback(struct urb *urb)
 167 {
 168         struct usb_serial_port  *port   = urb->context;
 169         unsigned char           *data   = urb->transfer_buffer;
 170         struct omninet_header   *header = (struct omninet_header *) &data[0];
 171         int status = urb->status;
 172         int result;
 173
 174         if (status) {
 175                 dev_dbg(&port->dev, "%s - nonzero read bulk status received: %d\n",
 176                         __func__, status);
 177                 return;
 178         }
 179
 180         if (urb->actual_length && header->oh_len) {
 181                 struct tty_struct *tty = tty_port_tty_get(&port->port);
 182                 if (tty) {
 183                         tty_insert_flip_string(tty, data + OMNINET_DATAOFFSET,
 184                                                         header->oh_len);
 185                         tty_flip_buffer_push(tty);
 186                         tty_kref_put(tty);
 187                 }
 188         }
 189
 190         /* Continue trying to always read  */
 191         result = usb_submit_urb(urb, GFP_ATOMIC);
 192         if (result)
 193                 dev_err(&port->dev,
 194                         "%s - failed resubmitting read urb, error %d\n",
 195                         __func__, result);
 196 }
 197
 198 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 199                                         const unsigned char *buf, int count)
 200 {
 201         struct usb_serial *serial = port->serial;
 202         struct usb_serial_port *wport = serial->port[1];
 203
 204         struct omninet_data *od = usb_get_serial_port_data(port);
 205         struct omninet_header *header = (struct omninet_header *)
 206                                         wport->write_urb->transfer_buffer;
 207
 208         int                     result;
 209
 210         if (count == 0) {
 211                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 212                 return 0;
 213         }
 214
 215         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 216                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 217                 return 0;
 218         }
 219
 220         count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
 221
 222         memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
 223                                                                 buf, count);
 224
 225         usb_serial_debug_data(&port->dev, __func__, count,
 226                               wport->write_urb->transfer_buffer);
 227
 228         header->oh_seq  = od->od_outseq++;
 229         header->oh_len  = count;
 230         header->oh_xxx  = 0x03;
 231         header->oh_pad  = 0x00;
 232
 233         /* send the data out the bulk port, always 64 bytes */
 234         wport->write_urb->transfer_buffer_length = 64;
 235
 236         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 237         if (result) {
 238                 set_bit(0, &wport->write_urbs_free);
 239                 dev_err_console(port,
 240                         "%s - failed submitting write urb, error %d\n",
 241                         __func__, result);
 242         } else
 243                 result = count;
 244
 245         return result;
 246 }
 247
 248
 249 static int omninet_write_room(struct tty_struct *tty)
 250 {
 251         struct usb_serial_port *port = tty->driver_data;
 252         struct usb_serial       *serial = port->serial;
 253         struct usb_serial_port  *wport  = serial->port[1];
 254
 255         int room = 0; /* Default: no room */
 256
 257         if (test_bit(0, &wport->write_urbs_free))
 258                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 259
 260         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 261
 262         return room;
 263 }
 264
 265 static void omninet_write_bulk_callback(struct urb *urb)
 266 {
 267 /*      struct omninet_header   *header = (struct omninet_header  *)
 268                                                 urb->transfer_buffer; */
 269         struct usb_serial_port  *port   =  urb->context;
 270         int status = urb->status;
 271
 272         set_bit(0, &port->write_urbs_free);
 273         if (status) {
 274                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 275                         __func__, status);
 276                 return;
 277         }
 278
 279         usb_serial_port_softint(port);
 280 }
 281
 282
 283 static void omninet_disconnect(struct usb_serial *serial)
 284 {
 285         struct usb_serial_port *wport = serial->port[1];
 286
 287         usb_kill_urb(wport->write_urb);
 288 }
 289
 290 module_usb_serial_driver(serial_drivers, id_table);
 291
 292 MODULE_AUTHOR(DRIVER_AUTHOR);
 293 MODULE_DESCRIPTION(DRIVER_DESC);
 294 MODULE_LICENSE("GPL");