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