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/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.xmit_fifo_size = 1024; 347 tmp.baud_base = 9600; 348 tmp.close_delay = 5*HZ; 349 tmp.closing_wait = 30*HZ; 350 351 if (copy_to_user(serial, &tmp, sizeof(*serial))) 352 return -EFAULT; 353 return 0; 354 } 355 356 static int opticon_ioctl(struct tty_struct *tty, 357 unsigned int cmd, unsigned long arg) 358 { 359 struct usb_serial_port *port = tty->driver_data; 360 361 switch (cmd) { 362 case TIOCGSERIAL: 363 return get_serial_info(port, 364 (struct serial_struct __user *)arg); 365 } 366 367 return -ENOIOCTLCMD; 368 } 369 370 static int opticon_port_probe(struct usb_serial_port *port) 371 { 372 struct opticon_private *priv; 373 374 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 375 if (!priv) 376 return -ENOMEM; 377 378 spin_lock_init(&priv->lock); 379 380 usb_set_serial_port_data(port, priv); 381 382 return 0; 383 } 384 385 static int opticon_port_remove(struct usb_serial_port *port) 386 { 387 struct opticon_private *priv = usb_get_serial_port_data(port); 388 389 kfree(priv); 390 391 return 0; 392 } 393 394 static struct usb_serial_driver opticon_device = { 395 .driver = { 396 .owner = THIS_MODULE, 397 .name = "opticon", 398 }, 399 .id_table = id_table, 400 .num_ports = 1, 401 .num_bulk_in = 1, 402 .bulk_in_size = 256, 403 .port_probe = opticon_port_probe, 404 .port_remove = opticon_port_remove, 405 .open = opticon_open, 406 .write = opticon_write, 407 .write_room = opticon_write_room, 408 .throttle = usb_serial_generic_throttle, 409 .unthrottle = usb_serial_generic_unthrottle, 410 .ioctl = opticon_ioctl, 411 .tiocmget = opticon_tiocmget, 412 .tiocmset = opticon_tiocmset, 413 .process_read_urb = opticon_process_read_urb, 414 }; 415 416 static struct usb_serial_driver * const serial_drivers[] = { 417 &opticon_device, NULL 418 }; 419 420 module_usb_serial_driver(serial_drivers, id_table); 421 422 MODULE_DESCRIPTION(DRIVER_DESC); 423 MODULE_LICENSE("GPL"); 424