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         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         return retval;
 124 }
 125
 126 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port)
 127 {
 128         struct opticon_private *priv = usb_get_serial_port_data(port);
 129         unsigned long flags;
 130         int res;
 131
 132         spin_lock_irqsave(&priv->lock, flags);
 133         priv->rts = false;
 134         spin_unlock_irqrestore(&priv->lock, flags);
 135
 136         /* Clear RTS line */
 137         send_control_msg(port, CONTROL_RTS, 0);
 138
 139         /* clear the halt status of the enpoint */
 140         usb_clear_halt(port->serial->dev, port->read_urb->pipe);
 141
 142         res = usb_serial_generic_open(tty, port);
 143         if (!res)
 144                 return res;
 145
 146         /* Request CTS line state, sometimes during opening the current
 147          * CTS state can be missed. */
 148         send_control_msg(port, RESEND_CTS_STATE, 1);
 149
 150         return res;
 151 }
 152
 153 static void opticon_write_control_callback(struct urb *urb)
 154 {
 155         struct usb_serial_port *port = urb->context;
 156         struct opticon_private *priv = usb_get_serial_port_data(port);
 157         int status = urb->status;
 158         unsigned long flags;
 159
 160         /* free up the transfer buffer, as usb_free_urb() does not do this */
 161         kfree(urb->transfer_buffer);
 162
 163         /* setup packet may be set if we're using it for writing */
 164         kfree(urb->setup_packet);
 165
 166         if (status)
 167                 dev_dbg(&port->dev,
 168                         "%s - non-zero urb status received: %d\n",
 169                         __func__, status);
 170
 171         spin_lock_irqsave(&priv->lock, flags);
 172         --priv->outstanding_urbs;
 173         spin_unlock_irqrestore(&priv->lock, flags);
 174
 175         usb_serial_port_softint(port);
 176 }
 177
 178 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port,
 179                          const unsigned char *buf, int count)
 180 {
 181         struct opticon_private *priv = usb_get_serial_port_data(port);
 182         struct usb_serial *serial = port->serial;
 183         struct urb *urb;
 184         unsigned char *buffer;
 185         unsigned long flags;
 186         int status;
 187         struct usb_ctrlrequest *dr;
 188
 189         spin_lock_irqsave(&priv->lock, flags);
 190         if (priv->outstanding_urbs > URB_UPPER_LIMIT) {
 191                 spin_unlock_irqrestore(&priv->lock, flags);
 192                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 193                 return 0;
 194         }
 195         priv->outstanding_urbs++;
 196         spin_unlock_irqrestore(&priv->lock, flags);
 197
 198         buffer = kmalloc(count, GFP_ATOMIC);
 199         if (!buffer) {
 200                 dev_err(&port->dev, "out of memory\n");
 201                 count = -ENOMEM;
 202
 203                 goto error_no_buffer;
 204         }
 205
 206         urb = usb_alloc_urb(0, GFP_ATOMIC);
 207         if (!urb) {
 208                 dev_err(&port->dev, "no more free urbs\n");
 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                 dev_err(&port->dev, "out of memory\n");
 222                 count = -ENOMEM;
 223                 goto error_no_dr;
 224         }
 225
 226         dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT;
 227         dr->bRequest = 0x01;
 228         dr->wValue = 0;
 229         dr->wIndex = 0;
 230         dr->wLength = cpu_to_le16(count);
 231
 232         usb_fill_control_urb(urb, serial->dev,
 233                 usb_sndctrlpipe(serial->dev, 0),
 234                 (unsigned char *)dr, buffer, count,
 235                 opticon_write_control_callback, port);
 236
 237         /* send it down the pipe */
 238         status = usb_submit_urb(urb, GFP_ATOMIC);
 239         if (status) {
 240                 dev_err(&port->dev,
 241                 "%s - usb_submit_urb(write endpoint) failed status = %d\n",
 242                                                         __func__, status);
 243                 count = status;
 244                 goto error;
 245         }
 246
 247         /* we are done with this urb, so let the host driver
 248          * really free it when it is finished with it */
 249         usb_free_urb(urb);
 250
 251         return count;
 252 error:
 253         kfree(dr);
 254 error_no_dr:
 255         usb_free_urb(urb);
 256 error_no_urb:
 257         kfree(buffer);
 258 error_no_buffer:
 259         spin_lock_irqsave(&priv->lock, flags);
 260         --priv->outstanding_urbs;
 261         spin_unlock_irqrestore(&priv->lock, flags);
 262         return count;
 263 }
 264
 265 static int opticon_write_room(struct tty_struct *tty)
 266 {
 267         struct usb_serial_port *port = tty->driver_data;
 268         struct opticon_private *priv = usb_get_serial_port_data(port);
 269         unsigned long flags;
 270
 271         /*
 272          * We really can take almost anything the user throws at us
 273          * but let's pick a nice big number to tell the tty
 274          * layer that we have lots of free space, unless we don't.
 275          */
 276         spin_lock_irqsave(&priv->lock, flags);
 277         if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) {
 278                 spin_unlock_irqrestore(&priv->lock, flags);
 279                 dev_dbg(&port->dev, "%s - write limit hit\n", __func__);
 280                 return 0;
 281         }
 282         spin_unlock_irqrestore(&priv->lock, flags);
 283
 284         return 2048;
 285 }
 286
 287 static int opticon_tiocmget(struct tty_struct *tty)
 288 {
 289         struct usb_serial_port *port = tty->driver_data;
 290         struct opticon_private *priv = usb_get_serial_port_data(port);
 291         unsigned long flags;
 292         int result = 0;
 293
 294         spin_lock_irqsave(&priv->lock, flags);
 295         if (priv->rts)
 296                 result |= TIOCM_RTS;
 297         if (priv->cts)
 298                 result |= TIOCM_CTS;
 299         spin_unlock_irqrestore(&priv->lock, flags);
 300
 301         dev_dbg(&port->dev, "%s - %x\n", __func__, result);
 302         return result;
 303 }
 304
 305 static int opticon_tiocmset(struct tty_struct *tty,
 306                            unsigned int set, unsigned int clear)
 307 {
 308         struct usb_serial_port *port = tty->driver_data;
 309         struct usb_serial *serial = port->serial;
 310         struct opticon_private *priv = usb_get_serial_port_data(port);
 311         unsigned long flags;
 312         bool rts;
 313         bool changed = false;
 314         int ret;
 315
 316         /* We only support RTS so we only handle that */
 317         spin_lock_irqsave(&priv->lock, flags);
 318
 319         rts = priv->rts;
 320         if (set & TIOCM_RTS)
 321                 priv->rts = true;
 322         if (clear & TIOCM_RTS)
 323                 priv->rts = false;
 324         changed = rts ^ priv->rts;
 325         spin_unlock_irqrestore(&priv->lock, flags);
 326
 327         if (!changed)
 328                 return 0;
 329
 330         /* Send the new RTS state to the connected device */
 331         mutex_lock(&serial->disc_mutex);
 332         if (!serial->disconnected)
 333                 ret = send_control_msg(port, CONTROL_RTS, !rts);
 334         else
 335                 ret = -ENODEV;
 336         mutex_unlock(&serial->disc_mutex);
 337
 338         return ret;
 339 }
 340
 341 static int get_serial_info(struct usb_serial_port *port,
 342                            struct serial_struct __user *serial)
 343 {
 344         struct serial_struct tmp;
 345
 346         if (!serial)
 347                 return -EFAULT;
 348
 349         memset(&tmp, 0x00, sizeof(tmp));
 350
 351         /* fake emulate a 16550 uart to make userspace code happy */
 352         tmp.type                = PORT_16550A;
 353         tmp.line                = port->serial->minor;
 354         tmp.port                = 0;
 355         tmp.irq                 = 0;
 356         tmp.flags               = ASYNC_SKIP_TEST | ASYNC_AUTO_IRQ;
 357         tmp.xmit_fifo_size      = 1024;
 358         tmp.baud_base           = 9600;
 359         tmp.close_delay         = 5*HZ;
 360         tmp.closing_wait        = 30*HZ;
 361
 362         if (copy_to_user(serial, &tmp, sizeof(*serial)))
 363                 return -EFAULT;
 364         return 0;
 365 }
 366
 367 static int opticon_ioctl(struct tty_struct *tty,
 368                          unsigned int cmd, unsigned long arg)
 369 {
 370         struct usb_serial_port *port = tty->driver_data;
 371
 372         dev_dbg(&port->dev, "%s - port %d, cmd = 0x%x\n", __func__, port->number, cmd);
 373
 374         switch (cmd) {
 375         case TIOCGSERIAL:
 376                 return get_serial_info(port,
 377                                        (struct serial_struct __user *)arg);
 378         }
 379
 380         return -ENOIOCTLCMD;
 381 }
 382
 383 static int opticon_startup(struct usb_serial *serial)
 384 {
 385         if (!serial->num_bulk_in) {
 386                 dev_err(&serial->dev->dev, "no bulk in endpoint\n");
 387                 return -ENODEV;
 388         }
 389
 390         return 0;
 391 }
 392
 393 static int opticon_port_probe(struct usb_serial_port *port)
 394 {
 395         struct opticon_private *priv;
 396
 397         priv = kzalloc(sizeof(*priv), GFP_KERNEL);
 398         if (!priv)
 399                 return -ENOMEM;
 400
 401         spin_lock_init(&priv->lock);
 402
 403         usb_set_serial_port_data(port, priv);
 404
 405         return 0;
 406 }
 407
 408 static int opticon_port_remove(struct usb_serial_port *port)
 409 {
 410         struct opticon_private *priv = usb_get_serial_port_data(port);
 411
 412         kfree(priv);
 413
 414         return 0;
 415 }
 416
 417 static struct usb_serial_driver opticon_device = {
 418         .driver = {
 419                 .owner =        THIS_MODULE,
 420                 .name =         "opticon",
 421         },
 422         .id_table =             id_table,
 423         .num_ports =            1,
 424         .bulk_in_size =         256,
 425         .attach =               opticon_startup,
 426         .port_probe =           opticon_port_probe,
 427         .port_remove =          opticon_port_remove,
 428         .open =                 opticon_open,
 429         .write =                opticon_write,
 430         .write_room =           opticon_write_room,
 431         .throttle =             usb_serial_generic_throttle,
 432         .unthrottle =           usb_serial_generic_unthrottle,
 433         .ioctl =                opticon_ioctl,
 434         .tiocmget =             opticon_tiocmget,
 435         .tiocmset =             opticon_tiocmset,
 436         .process_read_urb =     opticon_process_read_urb,
 437 };
 438
 439 static struct usb_serial_driver * const serial_drivers[] = {
 440         &opticon_device, NULL
 441 };
 442
 443 module_usb_serial_driver(serial_drivers, id_table);
 444
 445 MODULE_DESCRIPTION(DRIVER_DESC);
 446 MODULE_LICENSE("GPL");