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