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