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"); 447