Pileus Git - ~andy/linux/blob - drivers/usb/serial/opticon.c

   1 /*
   2  * Opticon USB barcode to serial driver
   3  *
   4  * Copyright (C) 2011 - 2012 Johan Hovold <jhovold@gmail.com>
   5  * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com>
   6  * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de>
   7  * Copyright (C) 2008 - 2009 Novell Inc.
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License version
  11  *      2 as published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/init.h>
  16 #include <linux/tty.h>
  17 #include <linux/tty_driver.h>
  18 #include <linux/slab.h>
  19 #include <linux/tty_flip.h>
  20 #include <linux/serial.h>
  21 #include <linux/module.h>
  22 #include <linux/usb.h>
  23 #include <linux/usb/serial.h>
  24 #include <linux/uaccess.h>
  25
  26 #define CONTROL_RTS                     0x02
  27 #define RESEND_CTS_STATE        0x03
  28
  29 /* max number of write urbs in flight */
  30 #define URB_UPPER_LIMIT 8
  31
  32 /* This driver works for the Opticon 1D barcode reader
  33  * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */
  34 #define DRIVER_DESC     "Opticon USB barcode to serial driver (1D)"
  35
  36 static const struct usb_device_id id_table[] = {
  37         { USB_DEVICE(0x065a, 0x0009) },
  38         { },
  39 };
  40 MODULE_DEVICE_TABLE(usb, id_table);
  41
  42 /* This structure holds all of the individual device information */
  43 struct opticon_private {
  44         spinlock_t lock;        /* protects the following flags */
  45         bool rts;
  46         bool cts;
  47         int outstanding_urbs;
  48 };
  49
  50
  51 static void opticon_process_data_packet(struct usb_serial_port *port,
  52                                         const unsigned char *buf, size_t len)
  53 {
  54         struct tty_struct *tty;
  55
  56         tty = tty_port_tty_get(&port->port);
  57         if (!tty)
  58                 return;
  59
  60         tty_insert_flip_string(tty, buf, len);
  61         tty_flip_buffer_push(tty);
  62         tty_kref_put(tty);
  63 }
  64
  65 static void opticon_process_status_packet(struct usb_serial_port *port,
  66                                         const unsigned char *buf, size_t len)
  67 {
  68         struct opticon_private *priv = usb_get_serial_port_data(port);
  69         unsigned long flags;
  70
  71         spin_lock_irqsave(&priv->lock, flags);
  72         if (buf[0] == 0x00)
  73                 priv->cts = false;
  74         else
  75                 priv->cts = true;
  76         spin_unlock_irqrestore(&priv->lock, flags);
  77 }
  78
  79 static void opticon_process_read_urb(struct urb *urb)
  80 {
  81         struct usb_serial_port *port = urb->context;
  82         const unsigned char *hdr = urb->transfer_buffer;
  83         const unsigned char *data = hdr + 2;
  84         size_t data_len = urb->actual_length - 2;
  85
  86         if (urb->actual_length <= 2) {
  87                 dev_dbg(&port->dev, "malformed packet received: %d bytes\n",
  88                                                         urb->actual_length);
  89                 return;
  90         }
  91         /*
  92          * Data from the device comes with a 2 byte header:
  93          *
  94          * <0x00><0x00>data...
  95          *      This is real data to be sent to the tty layer
  96          * <0x00><0x01>level
  97          *      This is a CTS level change, the third byte is the CTS
  98          *      value (0 for low, 1 for high).
  99          */
 100         if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) {
 101                 opticon_process_data_packet(port, data, data_len);
 102         } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) {
 103                 opticon_process_status_packet(port, data, data_len);
 104         } else {
 105                 dev_dbg(&port->dev, "unknown packet received: %02x %02x\n",
 106                                                         hdr[0], hdr[1]);
 107         }
 108 }
 109
 110 static int send_control_msg(struct usb_serial_port *port, u8 requesttype,
 111                                 u8 val)
 112 {
 113         struct usb_serial *serial = port->serial;
 114         int retval;
 115         u8 *buffer;
 116
 117         buffer = kzalloc(1, GFP_KERNEL);
 118         if (!buffer)
 119                 return -ENOMEM;
 120
 121         buffer[0] = val;
 122         /* Send the message to the vendor control endpoint
 123          * of the connected device */
 124         retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
 125                                 requesttype,
 126                                 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE,
 127                                 0, 0, buffer, 1, 0);
 128         kfree(buffer);
 129
 130         return retval;
 131 }
 132
 133 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 134 {
 135         struct opticon_private *priv = usb_get_serial_port_data(port);
 136         unsigned long flags;
 137         int res;
 138
 139         spin_lock_irqsave(&priv->lock, flags);
 140         priv->rts = false;
 141         spin_unlock_irqrestore(&priv->lock, flags);
 142
 143         /* Clear RTS line */
 144         send_control_msg(port, CONTROL_RTS, 0);
 145
 146         /* clear the halt status of the enpoint */
 147         usb_clear_halt(port->serial->dev, port->read_urb->pipe);
 148
 149         res = usb_serial_generic_open(tty, port);
 150         if (!res)
 151                 return res;
 152
 153         /* Request CTS line state, sometimes during opening the current
 154          * CTS state can be missed. */
 155         send_control_msg(port, RESEND_CTS_STATE, 1);
 156
 157         return res;
 158 }
 159
 160 static void opticon_write_control_callback(struct urb *urb)
 161 {
 162         struct usb_serial_port *port = urb->context;
 163         struct opticon_private *priv = usb_get_serial_port_data(port);
 164         int status = urb->status;
 165         unsigned long flags;
 166
 167         /* free up the transfer buffer, as usb_free_urb() does not do this */
 168         kfree(urb->transfer_buffer);
 169
 170         /* setup packet may be set if we're using it for writing */
 171         kfree(urb->setup_packet);
 172
 173         if (status)
 174                 dev_dbg(&port->dev,
 175                         "%s - non-zero urb status received: %d\n",
 176                         __func__, status);
 177
 178         spin_lock_irqsave(&priv->lock, flags);
 179         --priv->outstanding_urbs;
 180         spin_unlock_irqrestore(&priv->lock, flags);
 181
 182         usb_serial_port_softint(port);
 183 }
 184
 185 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 186                          const unsigned char *buf, int count)
 187 {
 188         struct opticon_private *priv = usb_get_serial_port_data(port);
 189         struct usb_serial *serial = port->serial;
 190         struct urb *urb;
 191         unsigned char *buffer;
 192         unsigned long flags;
 193         int status;
 194         struct usb_ctrlrequest *dr;
 195
 196         spin_lock_irqsave(&priv->lock, flags);
 197         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 198                 spin_unlock_irqrestore(&priv->lock, flags);
 199                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 200                 return 0;
 201         }
 202         priv->outstanding_urbs++;
 203         spin_unlock_irqrestore(&priv->lock, flags);
 204
 205         buffer = kmalloc(count, GFP_ATOMIC);
 206         if (!buffer) {
 207                 dev_err(&port->dev, "out of memory\n");
 208                 count = -ENOMEM;
 209
 210                 goto error_no_buffer;
 211         }
 212
 213         urb = usb_alloc_urb(0, GFP_ATOMIC);
 214         if (!urb) {
 215                 dev_err(&port->dev, "no more free urbs\n");
 216                 count = -ENOMEM;
 217                 goto error_no_urb;
 218         }
 219
 220         memcpy(buffer, buf, count);
 221
 222         usb_serial_debug_data(&port->dev, __func__, count, buffer);
 223
 224         /* The conncected devices do not have a bulk write endpoint,
 225          * to transmit data to de barcode device the control endpoint is used */
 226         dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
 227         if (!dr) {
 228                 dev_err(&port->dev, "out of memory\n");
 229                 count = -ENOMEM;
 230                 goto error_no_dr;
 231         }
 232
 233         dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 234         dr->bRequest = 0x01;
 235         dr->wValue = 0;
 236         dr->wIndex = 0;
 237         dr->wLength = cpu_to_le16(count);
 238
 239         usb_fill_control_urb(urb, serial->dev,
 240                 usb_sndctrlpipe(serial->dev, 0),
 241                 (unsigned char *)dr, buffer, count,
 242                 opticon_write_control_callback, port);
 243
 244         /* send it down the pipe */
 245         status = usb_submit_urb(urb, GFP_ATOMIC);
 246         if (status) {
 247                 dev_err(&port->dev,
 248                 "%s - usb_submit_urb(write endpoint) failed status = %d\n",
 249                                                         __func__, status);
 250                 count = status;
 251                 goto error;
 252         }
 253
 254         /* we are done with this urb, so let the host driver
 255          * really free it when it is finished with it */
 256         usb_free_urb(urb);
 257
 258         return count;
 259 error:
 260         kfree(dr);
 261 error_no_dr:
 262         usb_free_urb(urb);
 263 error_no_urb:
 264         kfree(buffer);
 265 error_no_buffer:
 266         spin_lock_irqsave(&priv->lock, flags);
 267         --priv->outstanding_urbs;
 268         spin_unlock_irqrestore(&priv->lock, flags);
 269         return count;
 270 }
 271
 272 static int opticon_write_room(struct tty_struct *tty)
 273 {
 274         struct usb_serial_port *port = tty->driver_data;
 275         struct opticon_private *priv = usb_get_serial_port_data(port);
 276         unsigned long flags;
 277
 278         /*
 279          * We really can take almost anything the user throws at us
 280          * but let's pick a nice big number to tell the tty
 281          * layer that we have lots of free space, unless we don't.
 282          */
 283         spin_lock_irqsave(&priv->lock, flags);
 284         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 285                 spin_unlock_irqrestore(&priv->lock, flags);
 286                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 287                 return 0;
 288         }
 289         spin_unlock_irqrestore(&priv->lock, flags);
 290
 291         return 2048;
 292 }
 293
 294 static int opticon_tiocmget(struct tty_struct *tty)
 295 {
 296         struct usb_serial_port *port = tty->driver_data;
 297         struct opticon_private *priv = usb_get_serial_port_data(port);
 298         unsigned long flags;
 299         int result = 0;
 300
 301         spin_lock_irqsave(&priv->lock, flags);
 302         if (priv->rts)
 303                 result |= TIOCM_RTS;
 304         if (priv->cts)
 305                 result |= TIOCM_CTS;
 306         spin_unlock_irqrestore(&priv->lock, flags);
 307
 308         dev_dbg(&port->dev, "%s - %x\n", __func__, result);
 309         return result;
 310 }
 311
 312 static int opticon_tiocmset(struct tty_struct *tty,
 313                            unsigned int set, unsigned int clear)
 314 {
 315         struct usb_serial_port *port = tty->driver_data;
 316         struct usb_serial *serial = port->serial;
 317         struct opticon_private *priv = usb_get_serial_port_data(port);
 318         unsigned long flags;
 319         bool rts;
 320         bool changed = false;
 321         int ret;
 322
 323         /* We only support RTS so we only handle that */
 324         spin_lock_irqsave(&priv->lock, flags);
 325
 326         rts = priv->rts;
 327         if (set & TIOCM_RTS)
 328                 priv->rts = true;
 329         if (clear & TIOCM_RTS)
 330                 priv->rts = false;
 331         changed = rts ^ priv->rts;
 332         spin_unlock_irqrestore(&priv->lock, flags);
 333
 334         if (!changed)
 335                 return 0;
 336
 337         /* Send the new RTS state to the connected device */
 338         mutex_lock(&serial->disc_mutex);
 339         if (!serial->disconnected)
 340                 ret = send_control_msg(port, CONTROL_RTS, !rts);
 341         else
 342                 ret = -ENODEV;
 343         mutex_unlock(&serial->disc_mutex);
 344
 345         return ret;
 346 }
 347
 348 static int get_serial_info(struct usb_serial_port *port,
 349                            struct serial_struct __user *serial)
 350 {
 351         struct serial_struct tmp;
 352
 353         if (!serial)
 354                 return -EFAULT;
 355
 356         memset(&tmp, 0x00, sizeof(tmp));
 357
 358         /* fake emulate a 16550 uart to make userspace code happy */
 359         tmp.type                = PORT_16550A;
 360         tmp.line                = port->serial->minor;
 361         tmp.port                = 0;
 362         tmp.irq                 = 0;
 363         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 364         tmp.xmit_fifo_size      = 1024;
 365         tmp.baud_base           = 9600;
 366         tmp.close_delay         = 5*HZ;
 367         tmp.closing_wait        = 30*HZ;
 368
 369         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 370                 return -EFAULT;
 371         return 0;
 372 }
 373
 374 static int opticon_ioctl(struct tty_struct *tty,
 375                          unsigned int cmd, unsigned long arg)
 376 {
 377         struct usb_serial_port *port = tty->driver_data;
 378
 379         dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
 380
 381         switch (cmd) {
 382         case TIOCGSERIAL:
 383                 return get_serial_info(port,
 384                                        (struct serial_struct __user *)arg);
 385         }
 386
 387         return -ENOIOCTLCMD;
 388 }
 389
 390 static int opticon_startup(struct usb_serial *serial)
 391 {
 392         if (!serial->num_bulk_in) {
 393                 dev_err(&serial->dev->dev, "no bulk in endpoint\n");
 394                 return -ENODEV;
 395         }
 396
 397         return 0;
 398 }
 399
 400 static int opticon_port_probe(struct usb_serial_port *port)
 401 {
 402         struct opticon_private *priv;
 403
 404         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 405         if (!priv)
 406                 return -ENOMEM;
 407
 408         spin_lock_init(&priv->lock);
 409
 410         usb_set_serial_port_data(port, priv);
 411
 412         return 0;
 413 }
 414
 415 static int opticon_port_remove(struct usb_serial_port *port)
 416 {
 417         struct opticon_private *priv = usb_get_serial_port_data(port);
 418
 419         kfree(priv);
 420
 421         return 0;
 422 }
 423
 424 static struct usb_serial_driver opticon_device = {
 425         .driver = {
 426                 .owner =        THIS_MODULE,
 427                 .name =         "opticon",
 428         },
 429         .id_table =             id_table,
 430         .num_ports =            1,
 431         .bulk_in_size =         256,
 432         .attach =               opticon_startup,
 433         .port_probe =           opticon_port_probe,
 434         .port_remove =          opticon_port_remove,
 435         .open =                 opticon_open,
 436         .write =                opticon_write,
 437         .write_room =           opticon_write_room,
 438         .throttle =             usb_serial_generic_throttle,
 439         .unthrottle =           usb_serial_generic_unthrottle,
 440         .ioctl =                opticon_ioctl,
 441         .tiocmget =             opticon_tiocmget,
 442         .tiocmset =             opticon_tiocmset,
 443         .process_read_urb =     opticon_process_read_urb,
 444 };
 445
 446 static struct usb_serial_driver * const serial_drivers[] = {
 447         &opticon_device, NULL
 448 };
 449
 450 module_usb_serial_driver(serial_drivers, id_table);
 451
 452 MODULE_DESCRIPTION(DRIVER_DESC);
 453 MODULE_LICENSE("GPL");