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