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/slab.h>
  17 #include <linux/tty.h>
  18 #include <linux/tty_driver.h>
  19 #include <linux/tty_flip.h>
  20 #include <linux/module.h>
  21 #include <linux/uaccess.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/serial.h>
  24
  25 #define DRIVER_AUTHOR "Alessandro Zummo"
  26 #define DRIVER_DESC "USB ZyXEL omni.net LCD PLUS Driver"
  27
  28 #define ZYXEL_VENDOR_ID         0x0586
  29 #define ZYXEL_OMNINET_ID        0x1000
  30 #define ZYXEL_OMNI_56K_PLUS_ID  0x1500
  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_process_read_urb(struct urb *urb);
  37 static void omninet_write_bulk_callback(struct urb *urb);
  38 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  39                                 const unsigned char *buf, int count);
  40 static int  omninet_write_room(struct tty_struct *tty);
  41 static void omninet_disconnect(struct usb_serial *serial);
  42 static int omninet_attach(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, ZYXEL_OMNI_56K_PLUS_ID) },
  49         { USB_DEVICE(ZYXEL_VENDOR_ID, BT_IGNITIONPRO_ID) },
  50         { }                                             /* Terminating entry */
  51 };
  52 MODULE_DEVICE_TABLE(usb, id_table);
  53
  54 static struct usb_serial_driver zyxel_omninet_device = {
  55         .driver = {
  56                 .owner =        THIS_MODULE,
  57                 .name =         "omninet",
  58         },
  59         .description =          "ZyXEL - omni.net lcd plus usb",
  60         .id_table =             id_table,
  61         .num_ports =            1,
  62         .attach =               omninet_attach,
  63         .port_probe =           omninet_port_probe,
  64         .port_remove =          omninet_port_remove,
  65         .open =                 omninet_open,
  66         .write =                omninet_write,
  67         .write_room =           omninet_write_room,
  68         .write_bulk_callback =  omninet_write_bulk_callback,
  69         .process_read_urb =     omninet_process_read_urb,
  70         .disconnect =           omninet_disconnect,
  71 };
  72
  73 static struct usb_serial_driver * const serial_drivers[] = {
  74         &zyxel_omninet_device, NULL
  75 };
  76
  77
  78 /*
  79  * The protocol.
  80  *
  81  * The omni.net always exchange 64 bytes of data with the host. The first
  82  * four bytes are the control header.
  83  *
  84  * oh_seq is a sequence number. Don't know if/how it's used.
  85  * oh_len is the length of the data bytes in the packet.
  86  * oh_xxx Bit-mapped, related to handshaking and status info.
  87  *      I normally set it to 0x03 in transmitted frames.
  88  *      7: Active when the TA is in a CONNECTed state.
  89  *      6: unknown
  90  *      5: handshaking, unknown
  91  *      4: handshaking, unknown
  92  *      3: unknown, usually 0
  93  *      2: unknown, usually 0
  94  *      1: handshaking, unknown, usually set to 1 in transmitted frames
  95  *      0: handshaking, unknown, usually set to 1 in transmitted frames
  96  * oh_pad Probably a pad byte.
  97  *
  98  * After the header you will find data bytes if oh_len was greater than zero.
  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_attach(struct usb_serial *serial)
 112 {
 113         /* The second bulk-out endpoint is used for writing. */
 114         if (serial->num_bulk_out < 2) {
 115                 dev_err(&serial->interface->dev, "missing endpoints\n");
 116                 return -ENODEV;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static int omninet_port_probe(struct usb_serial_port *port)
 123 {
 124         struct omninet_data *od;
 125
 126         od = kzalloc(sizeof(*od), GFP_KERNEL);
 127         if (!od)
 128                 return -ENOMEM;
 129
 130         usb_set_serial_port_data(port, od);
 131
 132         return 0;
 133 }
 134
 135 static int omninet_port_remove(struct usb_serial_port *port)
 136 {
 137         struct omninet_data *od;
 138
 139         od = usb_get_serial_port_data(port);
 140         kfree(od);
 141
 142         return 0;
 143 }
 144
 145 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
 146 {
 147         return usb_serial_generic_open(tty, port);
 148 }
 149
 150 #define OMNINET_HEADERLEN       4
 151 #define OMNINET_BULKOUTSIZE     64
 152 #define OMNINET_PAYLOADSIZE     (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
 153
 154 static void omninet_process_read_urb(struct urb *urb)
 155 {
 156         struct usb_serial_port *port = urb->context;
 157         const struct omninet_header *hdr = urb->transfer_buffer;
 158         const unsigned char *data;
 159         size_t data_len;
 160
 161         if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
 162                 return;
 163
 164         data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
 165         data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
 166                                                                 hdr->oh_len);
 167         tty_insert_flip_string(&port->port, data, data_len);
 168         tty_flip_buffer_push(&port->port);
 169 }
 170
 171 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 172                                         const unsigned char *buf, int count)
 173 {
 174         struct usb_serial *serial = port->serial;
 175         struct usb_serial_port *wport = serial->port[1];
 176
 177         struct omninet_data *od = usb_get_serial_port_data(port);
 178         struct omninet_header *header = (struct omninet_header *)
 179                                         wport->write_urb->transfer_buffer;
 180
 181         int                     result;
 182
 183         if (count == 0) {
 184                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 185                 return 0;
 186         }
 187
 188         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 189                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 190                 return 0;
 191         }
 192
 193         count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;
 194
 195         memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
 196                                                                 buf, count);
 197
 198         usb_serial_debug_data(&port->dev, __func__, count,
 199                               wport->write_urb->transfer_buffer);
 200
 201         header->oh_seq  = od->od_outseq++;
 202         header->oh_len  = count;
 203         header->oh_xxx  = 0x03;
 204         header->oh_pad  = 0x00;
 205
 206         /* send the data out the bulk port, always 64 bytes */
 207         wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;
 208
 209         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 210         if (result) {
 211                 set_bit(0, &wport->write_urbs_free);
 212                 dev_err_console(port,
 213                         "%s - failed submitting write urb, error %d\n",
 214                         __func__, result);
 215         } else
 216                 result = count;
 217
 218         return result;
 219 }
 220
 221
 222 static int omninet_write_room(struct tty_struct *tty)
 223 {
 224         struct usb_serial_port *port = tty->driver_data;
 225         struct usb_serial       *serial = port->serial;
 226         struct usb_serial_port  *wport  = serial->port[1];
 227
 228         int room = 0; /* Default: no room */
 229
 230         if (test_bit(0, &wport->write_urbs_free))
 231                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 232
 233         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 234
 235         return room;
 236 }
 237
 238 static void omninet_write_bulk_callback(struct urb *urb)
 239 {
 240 /*      struct omninet_header   *header = (struct omninet_header  *)
 241                                                 urb->transfer_buffer; */
 242         struct usb_serial_port  *port   =  urb->context;
 243         int status = urb->status;
 244
 245         set_bit(0, &port->write_urbs_free);
 246         if (status) {
 247                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 248                         __func__, status);
 249                 return;
 250         }
 251
 252         usb_serial_port_softint(port);
 253 }
 254
 255
 256 static void omninet_disconnect(struct usb_serial *serial)
 257 {
 258         struct usb_serial_port *wport = serial->port[1];
 259
 260         usb_kill_urb(wport->write_urb);
 261 }
 262
 263 module_usb_serial_driver(serial_drivers, id_table);
 264
 265 MODULE_AUTHOR(DRIVER_AUTHOR);
 266 MODULE_DESCRIPTION(DRIVER_DESC);
 267 MODULE_LICENSE("GPL");