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         struct usb_serial       *serial = port->serial;
 146         struct usb_serial_port  *wport;
 147
 148         wport = serial->port[1];
 149         tty_port_tty_set(&wport->port, tty);
 150
 151         return usb_serial_generic_open(tty, port);
 152 }
 153
 154 #define OMNINET_HEADERLEN       4
 155 #define OMNINET_BULKOUTSIZE     64
 156 #define OMNINET_PAYLOADSIZE     (OMNINET_BULKOUTSIZE - OMNINET_HEADERLEN)
 157
 158 static void omninet_process_read_urb(struct urb *urb)
 159 {
 160         struct usb_serial_port *port = urb->context;
 161         const struct omninet_header *hdr = urb->transfer_buffer;
 162         const unsigned char *data;
 163         size_t data_len;
 164
 165         if (urb->actual_length <= OMNINET_HEADERLEN || !hdr->oh_len)
 166                 return;
 167
 168         data = (char *)urb->transfer_buffer + OMNINET_HEADERLEN;
 169         data_len = min_t(size_t, urb->actual_length - OMNINET_HEADERLEN,
 170                                                                 hdr->oh_len);
 171         tty_insert_flip_string(&port->port, data, data_len);
 172         tty_flip_buffer_push(&port->port);
 173 }
 174
 175 static int omninet_write(struct tty_struct *tty, struct usb_serial_port *port,
 176                                         const unsigned char *buf, int count)
 177 {
 178         struct usb_serial *serial = port->serial;
 179         struct usb_serial_port *wport = serial->port[1];
 180
 181         struct omninet_data *od = usb_get_serial_port_data(port);
 182         struct omninet_header *header = (struct omninet_header *)
 183                                         wport->write_urb->transfer_buffer;
 184
 185         int                     result;
 186
 187         if (count == 0) {
 188                 dev_dbg(&port->dev, "%s - write request of 0 bytes\n", __func__);
 189                 return 0;
 190         }
 191
 192         if (!test_and_clear_bit(0, &port->write_urbs_free)) {
 193                 dev_dbg(&port->dev, "%s - already writing\n", __func__);
 194                 return 0;
 195         }
 196
 197         count = (count > OMNINET_PAYLOADSIZE) ? OMNINET_PAYLOADSIZE : count;
 198
 199         memcpy(wport->write_urb->transfer_buffer + OMNINET_HEADERLEN,
 200                                                                 buf, count);
 201
 202         usb_serial_debug_data(&port->dev, __func__, count,
 203                               wport->write_urb->transfer_buffer);
 204
 205         header->oh_seq  = od->od_outseq++;
 206         header->oh_len  = count;
 207         header->oh_xxx  = 0x03;
 208         header->oh_pad  = 0x00;
 209
 210         /* send the data out the bulk port, always 64 bytes */
 211         wport->write_urb->transfer_buffer_length = OMNINET_BULKOUTSIZE;
 212
 213         result = usb_submit_urb(wport->write_urb, GFP_ATOMIC);
 214         if (result) {
 215                 set_bit(0, &wport->write_urbs_free);
 216                 dev_err_console(port,
 217                         "%s - failed submitting write urb, error %d\n",
 218                         __func__, result);
 219         } else
 220                 result = count;
 221
 222         return result;
 223 }
 224
 225
 226 static int omninet_write_room(struct tty_struct *tty)
 227 {
 228         struct usb_serial_port *port = tty->driver_data;
 229         struct usb_serial       *serial = port->serial;
 230         struct usb_serial_port  *wport  = serial->port[1];
 231
 232         int room = 0; /* Default: no room */
 233
 234         if (test_bit(0, &wport->write_urbs_free))
 235                 room = wport->bulk_out_size - OMNINET_HEADERLEN;
 236
 237         dev_dbg(&port->dev, "%s - returns %d\n", __func__, room);
 238
 239         return room;
 240 }
 241
 242 static void omninet_write_bulk_callback(struct urb *urb)
 243 {
 244 /*      struct omninet_header   *header = (struct omninet_header  *)
 245                                                 urb->transfer_buffer; */
 246         struct usb_serial_port  *port   =  urb->context;
 247         int status = urb->status;
 248
 249         set_bit(0, &port->write_urbs_free);
 250         if (status) {
 251                 dev_dbg(&port->dev, "%s - nonzero write bulk status received: %d\n",
 252                         __func__, status);
 253                 return;
 254         }
 255
 256         usb_serial_port_softint(port);
 257 }
 258
 259
 260 static void omninet_disconnect(struct usb_serial *serial)
 261 {
 262         struct usb_serial_port *wport = serial->port[1];
 263
 264         usb_kill_urb(wport->write_urb);
 265 }
 266
 267 module_usb_serial_driver(serial_drivers, id_table);
 268
 269 MODULE_AUTHOR(DRIVER_AUTHOR);
 270 MODULE_DESCRIPTION(DRIVER_DESC);
 271 MODULE_LICENSE("GPL");