drivers/usb/serial/symbolserial.c

   1 /*
   2  * Symbol USB barcode to serial driver
   3  *
   4  * Copyright (C) 2009 Greg Kroah-Hartman <gregkh@suse.de>
   5  * Copyright (C) 2009 Novell Inc.
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License version
   9  *      2 as published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/tty.h>
  15 #include <linux/tty_driver.h>
  16 #include <linux/tty_flip.h>
  17 #include <linux/module.h>
  18 #include <linux/usb.h>
  19 #include <linux/usb/serial.h>
  20 #include <linux/uaccess.h>
  21
  22 static int debug;
  23
  24 static struct usb_device_id id_table[] = {
  25         { USB_DEVICE(0x05e0, 0x0600) },
  26         { },
  27 };
  28 MODULE_DEVICE_TABLE(usb, id_table);
  29
  30 /* This structure holds all of the individual device information */
  31 struct symbol_private {
  32         struct usb_device *udev;
  33         struct usb_serial *serial;
  34         struct usb_serial_port *port;
  35         unsigned char *int_buffer;
  36         struct urb *int_urb;
  37         int buffer_size;
  38         u8 bInterval;
  39         u8 int_address;
  40         spinlock_t lock;        /* protects the following flags */
  41         bool throttled;
  42         bool actually_throttled;
  43         bool rts;
  44 };
  45
  46 static void symbol_int_callback(struct urb *urb)
  47 {
  48         struct symbol_private *priv = urb->context;
  49         unsigned char *data = urb->transfer_buffer;
  50         struct usb_serial_port *port = priv->port;
  51         int status = urb->status;
  52         struct tty_struct *tty;
  53         int result;
  54         int available_room = 0;
  55         int data_length;
  56
  57         dbg("%s - port %d", __func__, port->number);
  58
  59         switch (status) {
  60         case 0:
  61                 /* success */
  62                 break;
  63         case -ECONNRESET:
  64         case -ENOENT:
  65         case -ESHUTDOWN:
  66                 /* this urb is terminated, clean up */
  67                 dbg("%s - urb shutting down with status: %d",
  68                     __func__, status);
  69                 return;
  70         default:
  71                 dbg("%s - nonzero urb status received: %d",
  72                     __func__, status);
  73                 goto exit;
  74         }
  75
  76         usb_serial_debug_data(debug, &port->dev, __func__, urb->actual_length,
  77                               data);
  78
  79         if (urb->actual_length > 1) {
  80                 data_length = urb->actual_length - 1;
  81
  82                 /*
  83                  * Data from the device comes with a 1 byte header:
  84                  *
  85                  * <size of data>data...
  86                  *      This is real data to be sent to the tty layer
  87                  * we pretty much just ignore the size and send everything
  88                  * else to the tty layer.
  89                  */
  90                 tty = tty_port_tty_get(&port->port);
  91                 if (tty) {
  92                         available_room = tty_buffer_request_room(tty,
  93                                                         data_length);
  94                         if (available_room) {
  95                                 tty_insert_flip_string(tty, &data[1],
  96                                                        available_room);
  97                                 tty_flip_buffer_push(tty);
  98                         }
  99                         tty_kref_put(tty);
 100                 }
 101         } else {
 102                 dev_dbg(&priv->udev->dev,
 103                         "Improper ammount of data received from the device, "
 104                         "%d bytes", urb->actual_length);
 105         }
 106
 107 exit:
 108         spin_lock(&priv->lock);
 109
 110         /* Continue trying to always read if we should */
 111         if (!priv->throttled) {
 112                 usb_fill_int_urb(priv->int_urb, priv->udev,
 113                                  usb_rcvintpipe(priv->udev,
 114                                                 priv->int_address),
 115                                  priv->int_buffer, priv->buffer_size,
 116                                  symbol_int_callback, priv, priv->bInterval);
 117                 result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
 118                 if (result)
 119                         dev_err(&port->dev,
 120                             "%s - failed resubmitting read urb, error %d\n",
 121                                                         __func__, result);
 122         } else
 123                 priv->actually_throttled = true;
 124         spin_unlock(&priv->lock);
 125 }
 126
 127 static int symbol_open(struct tty_struct *tty, struct usb_serial_port *port)
 128 {
 129         struct symbol_private *priv = usb_get_serial_data(port->serial);
 130         unsigned long flags;
 131         int result = 0;
 132
 133         dbg("%s - port %d", __func__, port->number);
 134
 135         spin_lock_irqsave(&priv->lock, flags);
 136         priv->throttled = false;
 137         priv->actually_throttled = false;
 138         priv->port = port;
 139         spin_unlock_irqrestore(&priv->lock, flags);
 140
 141         /* Start reading from the device */
 142         usb_fill_int_urb(priv->int_urb, priv->udev,
 143                          usb_rcvintpipe(priv->udev, priv->int_address),
 144                          priv->int_buffer, priv->buffer_size,
 145                          symbol_int_callback, priv, priv->bInterval);
 146         result = usb_submit_urb(priv->int_urb, GFP_KERNEL);
 147         if (result)
 148                 dev_err(&port->dev,
 149                         "%s - failed resubmitting read urb, error %d\n",
 150                         __func__, result);
 151         return result;
 152 }
 153
 154 static void symbol_close(struct usb_serial_port *port)
 155 {
 156         struct symbol_private *priv = usb_get_serial_data(port->serial);
 157
 158         dbg("%s - port %d", __func__, port->number);
 159
 160         /* shutdown our urbs */
 161         usb_kill_urb(priv->int_urb);
 162 }
 163
 164 static void symbol_throttle(struct tty_struct *tty)
 165 {
 166         struct usb_serial_port *port = tty->driver_data;
 167         struct symbol_private *priv = usb_get_serial_data(port->serial);
 168         unsigned long flags;
 169
 170         dbg("%s - port %d", __func__, port->number);
 171         spin_lock_irqsave(&priv->lock, flags);
 172         priv->throttled = true;
 173         spin_unlock_irqrestore(&priv->lock, flags);
 174 }
 175
 176 static void symbol_unthrottle(struct tty_struct *tty)
 177 {
 178         struct usb_serial_port *port = tty->driver_data;
 179         struct symbol_private *priv = usb_get_serial_data(port->serial);
 180         unsigned long flags;
 181         int result;
 182
 183         dbg("%s - port %d", __func__, port->number);
 184
 185         spin_lock_irqsave(&priv->lock, flags);
 186         priv->throttled = false;
 187         priv->actually_throttled = false;
 188         spin_unlock_irqrestore(&priv->lock, flags);
 189
 190         priv->int_urb->dev = port->serial->dev;
 191         result = usb_submit_urb(priv->int_urb, GFP_ATOMIC);
 192         if (result)
 193                 dev_err(&port->dev,
 194                         "%s - failed submitting read urb, error %d\n",
 195                                                         __func__, result);
 196 }
 197
 198 static int symbol_startup(struct usb_serial *serial)
 199 {
 200         struct symbol_private *priv;
 201         struct usb_host_interface *intf;
 202         int i;
 203         int retval = -ENOMEM;
 204         bool int_in_found = false;
 205
 206         /* create our private serial structure */
 207         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 208         if (priv == NULL) {
 209                 dev_err(&serial->dev->dev, "%s - Out of memory\n", __func__);
 210                 return -ENOMEM;
 211         }
 212         spin_lock_init(&priv->lock);
 213         priv->serial = serial;
 214         priv->port = serial->port[0];
 215         priv->udev = serial->dev;
 216
 217         /* find our interrupt endpoint */
 218         intf = serial->interface->altsetting;
 219         for (i = 0; i < intf->desc.bNumEndpoints; ++i) {
 220                 struct usb_endpoint_descriptor *endpoint;
 221
 222                 endpoint = &intf->endpoint[i].desc;
 223                 if (!usb_endpoint_is_int_in(endpoint))
 224                         continue;
 225
 226                 priv->int_urb = usb_alloc_urb(0, GFP_KERNEL);
 227                 if (!priv->int_urb) {
 228                         dev_err(&priv->udev->dev, "out of memory\n");
 229                         goto error;
 230                 }
 231
 232                 priv->buffer_size = le16_to_cpu(endpoint->wMaxPacketSize) * 2;
 233                 priv->int_buffer = kmalloc(priv->buffer_size, GFP_KERNEL);
 234                 if (!priv->int_buffer) {
 235                         dev_err(&priv->udev->dev, "out of memory\n");
 236                         goto error;
 237                 }
 238
 239                 priv->int_address = endpoint->bEndpointAddress;
 240                 priv->bInterval = endpoint->bInterval;
 241
 242                 /* set up our int urb */
 243                 usb_fill_int_urb(priv->int_urb, priv->udev,
 244                                  usb_rcvintpipe(priv->udev,
 245                                                 endpoint->bEndpointAddress),
 246                                  priv->int_buffer, priv->buffer_size,
 247                                  symbol_int_callback, priv, priv->bInterval);
 248
 249                 int_in_found = true;
 250                 break;
 251                 }
 252
 253         if (!int_in_found) {
 254                 dev_err(&priv->udev->dev,
 255                         "Error - the proper endpoints were not found!\n");
 256                 goto error;
 257         }
 258
 259         usb_set_serial_data(serial, priv);
 260         return 0;
 261
 262 error:
 263         usb_free_urb(priv->int_urb);
 264         kfree(priv->int_buffer);
 265         kfree(priv);
 266         return retval;
 267 }
 268
 269 static void symbol_disconnect(struct usb_serial *serial)
 270 {
 271         struct symbol_private *priv = usb_get_serial_data(serial);
 272
 273         dbg("%s", __func__);
 274
 275         usb_kill_urb(priv->int_urb);
 276         usb_free_urb(priv->int_urb);
 277 }
 278
 279 static void symbol_release(struct usb_serial *serial)
 280 {
 281         struct symbol_private *priv = usb_get_serial_data(serial);
 282
 283         dbg("%s", __func__);
 284
 285         kfree(priv->int_buffer);
 286         kfree(priv);
 287 }
 288
 289 static struct usb_driver symbol_driver = {
 290         .name =                 "symbol",
 291         .probe =                usb_serial_probe,
 292         .disconnect =           usb_serial_disconnect,
 293         .id_table =             id_table,
 294         .no_dynamic_id =        1,
 295 };
 296
 297 static struct usb_serial_driver symbol_device = {
 298         .driver = {
 299                 .owner =        THIS_MODULE,
 300                 .name =         "symbol",
 301         },
 302         .id_table =             id_table,
 303         .usb_driver =           &symbol_driver,
 304         .num_ports =            1,
 305         .attach =               symbol_startup,
 306         .open =                 symbol_open,
 307         .close =                symbol_close,
 308         .disconnect =           symbol_disconnect,
 309         .release =              symbol_release,
 310         .throttle =             symbol_throttle,
 311         .unthrottle =           symbol_unthrottle,
 312 };
 313
 314 static int __init symbol_init(void)
 315 {
 316         int retval;
 317
 318         retval = usb_serial_register(&symbol_device);
 319         if (retval)
 320                 return retval;
 321         retval = usb_register(&symbol_driver);
 322         if (retval)
 323                 usb_serial_deregister(&symbol_device);
 324         return retval;
 325 }
 326
 327 static void __exit symbol_exit(void)
 328 {
 329         usb_deregister(&symbol_driver);
 330         usb_serial_deregister(&symbol_device);
 331 }
 332
 333 module_init(symbol_init);
 334 module_exit(symbol_exit);
 335 MODULE_LICENSE("GPL");
 336
 337 module_param(debug, bool, S_IRUGO | S_IWUSR);
 338 MODULE_PARM_DESC(debug, "Debug enabled or not");