drivers/usb/serial/opticon.c

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