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 /* This one seems to be a re-branded ZyXEL device */
  31 #define BT_IGNITIONPRO_ID       0x2000
  32
  33 /* function prototypes */
  34 static int  omninet_open(struct tty_struct *tty, struct usb_serial_port *port);
  35 static void omninet_process_read_urb(struct urb *urb);
  36 static void omninet_write_bulk_callback(struct urb *urb);
  37 static int  omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
  38                                 const unsigned char *buf, int count);
  39 static int  omninet_write_room(struct tty_struct *tty);
  40 static void omninet_disconnect(struct usb_serial *serial);
  41 static int omninet_attach(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         .attach =               omninet_attach,
  61         .port_probe =           omninet_port_probe,
  62         .port_remove =          omninet_port_remove,
  63         .open =                 omninet_open,
  64         .write =                omninet_write,
  65         .write_room =           omninet_write_room,
  66         .write_bulk_callback =  omninet_write_bulk_callback,
  67         .process_read_urb =     omninet_process_read_urb,
  68         .disconnect =           omninet_disconnect,
  69 };
  70
  71 static struct usb_serial_driver * const serial_drivers[] = {
  72         &zyxel_omninet_device, NULL
  73 };
  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.
  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 transmitted 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 transmitted frames
  93  *      0: handshaking, unknown, usually set to 1 in transmitted 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 struct omninet_header {
  99         __u8    oh_seq;
 100         __u8    oh_len;
 101         __u8    oh_xxx;
 102         __u8    oh_pad;
 103 };
 104
 105 struct omninet_data {
 106         __u8    od_outseq;      /* Sequence number for bulk_out URBs */
 107 };
 108
 109 static int omninet_attach(struct usb_serial *serial)
 110 {
 111         /* The second bulk-out endpoint is used for writing. */
 112         if (serial->num_bulk_out < 2) {
 113                 dev_err(&serial->interface->dev, "missing endpoints\n");
 114                 return -ENODEV;
 115         }
 116
 117         return 0;
 118 }
 119
 120 static int omninet_port_probe(struct usb_serial_port *port)
 121 {
 122         struct omninet_data *od;
 123
 124         od = kzalloc(sizeof(*od), GFP_KERNEL);
 125         if (!od)
 126                 return -ENOMEM;
 127
 128         usb_set_serial_port_data(port, od);
 129
 130         return 0;
 131 }
 132
 133 static int omninet_port_remove(struct usb_serial_port *port)
 134 {
 135         struct omninet_data *od;
 136
 137         od = usb_get_serial_port_data(port);
 138         kfree(od);
 139
 140         return 0;
 141 }
 142
 143 static int omninet_open(struct tty_struct *tty, struct usb_serial_port *port)
 144 {
 145         return usb_serial_generic_open(tty, port);
 146 }
 147
 148 #define OMNINET_HEADERLEN       4
 149 #define OMNINET_BULKOUTSIZE     64
 150 #define OMNINET_PAYLOADSIZE     (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
 151
 152 static void omninet_process_read_urb(struct urb *urb)
 153 {
 154         struct usb_serial_port *port = urb->context;
 155         const struct omninet_header *hdr = urb->transfer_buffer;
 156         const unsigned char *data;
 157         size_t data_len;
 158
 159         if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
 160                 return;
 161
 162         data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
 163         data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
 164                                                                 hdr->oh_len);
 165         tty_insert_flip_string(&port->port, data, data_len);
 166         tty_flip_buffer_push(&port->port);
 167 }
 168
 169 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 170                                         const unsigned char *buf, int count)
 171 {
 172         struct usb_serial *serial = port->serial;
 173         struct usb_serial_port *wport = serial->port[1];
 174
 175         struct omninet_data *od = usb_get_serial_port_data(port);
 176         struct omninet_header *header = (struct omninet_header *)
 177                                         wport->write_urb->transfer_buffer;
 178
 179         int                     result;
 180
 181         if (count == 0) {
 182                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 183                 return 0;
 184         }
 185
 186         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 187                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 188                 return 0;
 189         }
 190
 191         count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;
 192
 193         memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
 194                                                                 buf, count);
 195
 196         usb_serial_debug_data(&port->dev, __func__, count,
 197                               wport->write_urb->transfer_buffer);
 198
 199         header->oh_seq  = od->od_outseq++;
 200         header->oh_len  = count;
 201         header->oh_xxx  = 0x03;
 202         header->oh_pad  = 0x00;
 203
 204         /* send the data out the bulk port, always 64 bytes */
 205         wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;
 206
 207         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 208         if (result) {
 209                 set_bit(0, &wport->write_urbs_free);
 210                 dev_err_console(port,
 211                         "%s - failed submitting write urb, error %d\n",
 212                         __func__, result);
 213         } else
 214                 result = count;
 215
 216         return result;
 217 }
 218
 219
 220 static int omninet_write_room(struct tty_struct *tty)
 221 {
 222         struct usb_serial_port *port = tty->driver_data;
 223         struct usb_serial       *serial = port->serial;
 224         struct usb_serial_port  *wport  = serial->port[1];
 225
 226         int room = 0; /* Default: no room */
 227
 228         if (test_bit(0, &wport->write_urbs_free))
 229                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 230
 231         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 232
 233         return room;
 234 }
 235
 236 static void omninet_write_bulk_callback(struct urb *urb)
 237 {
 238 /*      struct omninet_header   *header = (struct omninet_header  *)
 239                                                 urb->transfer_buffer; */
 240         struct usb_serial_port  *port   =  urb->context;
 241         int status = urb->status;
 242
 243         set_bit(0, &port->write_urbs_free);
 244         if (status) {
 245                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 246                         __func__, status);
 247                 return;
 248         }
 249
 250         usb_serial_port_softint(port);
 251 }
 252
 253
 254 static void omninet_disconnect(struct usb_serial *serial)
 255 {
 256         struct usb_serial_port *wport = serial->port[1];
 257
 258         usb_kill_urb(wport->write_urb);
 259 }
 260
 261 module_usb_serial_driver(serial_drivers, id_table);
 262
 263 MODULE_AUTHOR(DRIVER_AUTHOR);
 264 MODULE_DESCRIPTION(DRIVER_DESC);
 265 MODULE_LICENSE("GPL");