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 /*
  78  * The protocol.
  79  *
  80  * The omni.net always exchange 64 bytes of data with the host. The first
  81  * four bytes are the control header.
  82  *
  83  * oh_seq is a sequence number. Don't know if/how it's used.
  84  * oh_len is the length of the data bytes in the packet.
  85  * oh_xxx Bit-mapped, related to handshaking and status info.
  86  *      I normally set it to 0x03 in transmitted frames.
  87  *      7: Active when the TA is in a CONNECTed state.
  88  *      6: unknown
  89  *      5: handshaking, unknown
  90  *      4: handshaking, unknown
  91  *      3: unknown, usually 0
  92  *      2: unknown, usually 0
  93  *      1: handshaking, unknown, usually set to 1 in transmitted frames
  94  *      0: handshaking, unknown, usually set to 1 in transmitted frames
  95  * oh_pad Probably a pad byte.
  96  *
  97  * After the header you will find data bytes if oh_len was greater than zero.
  98  */
  99 struct omninet_header {
 100         __u8    oh_seq;
 101         __u8    oh_len;
 102         __u8    oh_xxx;
 103         __u8    oh_pad;
 104 };
 105
 106 struct omninet_data {
 107         __u8    od_outseq;      /* Sequence number for bulk_out URBs */
 108 };
 109
 110 static int omninet_port_probe(struct usb_serial_port *port)
 111 {
 112         struct omninet_data *od;
 113
 114         od = kzalloc(sizeof(*od), GFP_KERNEL);
 115         if (!od)
 116                 return -ENOMEM;
 117
 118         usb_set_serial_port_data(port, od);
 119
 120         return 0;
 121 }
 122
 123 static int omninet_port_remove(struct usb_serial_port *port)
 124 {
 125         struct omninet_data *od;
 126
 127         od = usb_get_serial_port_data(port);
 128         kfree(od);
 129
 130         return 0;
 131 }
 132
 133 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
 134 {
 135         struct usb_serial       *serial = port->serial;
 136         struct usb_serial_port  *wport;
 137         int                     result = 0;
 138
 139         wport = serial->port[1];
 140         tty_port_tty_set(&wport->port, tty);
 141
 142         /* Start reading from the device */
 143         result = usb_submit_urb(port->read_urb, GFP_KERNEL);
 144         if (result)
 145                 dev_err(&port->dev,
 146                         "%s - failed submitting read urb, error %d\n",
 147                         __func__, result);
 148         return result;
 149 }
 150
 151 static void omninet_close(struct usb_serial_port *port)
 152 {
 153         usb_kill_urb(port->read_urb);
 154 }
 155
 156
 157 #define OMNINET_HEADERLEN       4
 158 #define OMNINET_BULKOUTSIZE     64
 159 #define OMNINET_PAYLOADSIZE     (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
 160
 161 static void omninet_read_bulk_callback(struct urb *urb)
 162 {
 163         struct usb_serial_port  *port   = urb->context;
 164         unsigned char           *data   = urb->transfer_buffer;
 165         struct omninet_header   *header = (struct omninet_header *) &data[0];
 166         int status = urb->status;
 167         int result;
 168
 169         if (status) {
 170                 dev_dbg(&port->dev, "%s - nonzero read bulk status received: %d\n",
 171                         __func__, status);
 172                 return;
 173         }
 174
 175         if (urb->actual_length && header->oh_len) {
 176                 tty_insert_flip_string(&port->port, data + OMNINET_HEADERLEN,
 177                                 header->oh_len);
 178                 tty_flip_buffer_push(&port->port);
 179         }
 180
 181         /* Continue trying to always read  */
 182         result = usb_submit_urb(urb, GFP_ATOMIC);
 183         if (result)
 184                 dev_err(&port->dev,
 185                         "%s - failed resubmitting read urb, error %d\n",
 186                         __func__, result);
 187 }
 188
 189 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 190                                         const unsigned char *buf, int count)
 191 {
 192         struct usb_serial *serial = port->serial;
 193         struct usb_serial_port *wport = serial->port[1];
 194
 195         struct omninet_data *od = usb_get_serial_port_data(port);
 196         struct omninet_header *header = (struct omninet_header *)
 197                                         wport->write_urb->transfer_buffer;
 198
 199         int                     result;
 200
 201         if (count == 0) {
 202                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 203                 return 0;
 204         }
 205
 206         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 207                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 208                 return 0;
 209         }
 210
 211         count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;
 212
 213         memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
 214                                                                 buf, count);
 215
 216         usb_serial_debug_data(&port->dev, __func__, count,
 217                               wport->write_urb->transfer_buffer);
 218
 219         header->oh_seq  = od->od_outseq++;
 220         header->oh_len  = count;
 221         header->oh_xxx  = 0x03;
 222         header->oh_pad  = 0x00;
 223
 224         /* send the data out the bulk port, always 64 bytes */
 225         wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;
 226
 227         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 228         if (result) {
 229                 set_bit(0, &wport->write_urbs_free);
 230                 dev_err_console(port,
 231                         "%s - failed submitting write urb, error %d\n",
 232                         __func__, result);
 233         } else
 234                 result = count;
 235
 236         return result;
 237 }
 238
 239
 240 static int omninet_write_room(struct tty_struct *tty)
 241 {
 242         struct usb_serial_port *port = tty->driver_data;
 243         struct usb_serial       *serial = port->serial;
 244         struct usb_serial_port  *wport  = serial->port[1];
 245
 246         int room = 0; /* Default: no room */
 247
 248         if (test_bit(0, &wport->write_urbs_free))
 249                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 250
 251         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 252
 253         return room;
 254 }
 255
 256 static void omninet_write_bulk_callback(struct urb *urb)
 257 {
 258 /*      struct omninet_header   *header = (struct omninet_header  *)
 259                                                 urb->transfer_buffer; */
 260         struct usb_serial_port  *port   =  urb->context;
 261         int status = urb->status;
 262
 263         set_bit(0, &port->write_urbs_free);
 264         if (status) {
 265                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 266                         __func__, status);
 267                 return;
 268         }
 269
 270         usb_serial_port_softint(port);
 271 }
 272
 273
 274 static void omninet_disconnect(struct usb_serial *serial)
 275 {
 276         struct usb_serial_port *wport = serial->port[1];
 277
 278         usb_kill_urb(wport->write_urb);
 279 }
 280
 281 module_usb_serial_driver(serial_drivers, id_table);
 282
 283 MODULE_AUTHOR(DRIVER_AUTHOR);
 284 MODULE_DESCRIPTION(DRIVER_DESC);
 285 MODULE_LICENSE("GPL");