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                 tty_insert_flip_string(&port->port, data + OMNINET_DATAOFFSET,
 178                                 header->oh_len);
 179                 tty_flip_buffer_push(&port->port);
 180         }
 181
 182         /* Continue trying to always read  */
 183         result = usb_submit_urb(urb, GFP_ATOMIC);
 184         if (result)
 185                 dev_err(&port->dev,
 186                         "%s - failed resubmitting read urb, error %d\n",
 187                         __func__, result);
 188 }
 189
 190 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 191                                         const unsigned char *buf, int count)
 192 {
 193         struct usb_serial *serial = port->serial;
 194         struct usb_serial_port *wport = serial->port[1];
 195
 196         struct omninet_data *od = usb_get_serial_port_data(port);
 197         struct omninet_header *header = (struct omninet_header *)
 198                                         wport->write_urb->transfer_buffer;
 199
 200         int                     result;
 201
 202         if (count == 0) {
 203                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 204                 return 0;
 205         }
 206
 207         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 208                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 209                 return 0;
 210         }
 211
 212         count = (count > OMNINET_BULKOUTSIZE) ? OMNINET_BULKOUTSIZE : count;
 213
 214         memcpy(wport->write_urb->transfer_buffer + OMNINET_DATAOFFSET,
 215                                                                 buf, count);
 216
 217         usb_serial_debug_data(&port->dev, __func__, count,
 218                               wport->write_urb->transfer_buffer);
 219
 220         header->oh_seq  = od->od_outseq++;
 221         header->oh_len  = count;
 222         header->oh_xxx  = 0x03;
 223         header->oh_pad  = 0x00;
 224
 225         /* send the data out the bulk port, always 64 bytes */
 226         wport->write_urb->transfer_buffer_length = 64;
 227
 228         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 229         if (result) {
 230                 set_bit(0, &wport->write_urbs_free);
 231                 dev_err_console(port,
 232                         "%s - failed submitting write urb, error %d\n",
 233                         __func__, result);
 234         } else
 235                 result = count;
 236
 237         return result;
 238 }
 239
 240
 241 static int omninet_write_room(struct tty_struct *tty)
 242 {
 243         struct usb_serial_port *port = tty->driver_data;
 244         struct usb_serial       *serial = port->serial;
 245         struct usb_serial_port  *wport  = serial->port[1];
 246
 247         int room = 0; /* Default: no room */
 248
 249         if (test_bit(0, &wport->write_urbs_free))
 250                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 251
 252         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 253
 254         return room;
 255 }
 256
 257 static void omninet_write_bulk_callback(struct urb *urb)
 258 {
 259 /*      struct omninet_header   *header = (struct omninet_header  *)
 260                                                 urb->transfer_buffer; */
 261         struct usb_serial_port  *port   =  urb->context;
 262         int status = urb->status;
 263
 264         set_bit(0, &port->write_urbs_free);
 265         if (status) {
 266                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 267                         __func__, status);
 268                 return;
 269         }
 270
 271         usb_serial_port_softint(port);
 272 }
 273
 274
 275 static void omninet_disconnect(struct usb_serial *serial)
 276 {
 277         struct usb_serial_port *wport = serial->port[1];
 278
 279         usb_kill_urb(wport->write_urb);
 280 }
 281
 282 module_usb_serial_driver(serial_drivers, id_table);
 283
 284 MODULE_AUTHOR(DRIVER_AUTHOR);
 285 MODULE_DESCRIPTION(DRIVER_DESC);
 286 MODULE_LICENSE("GPL");