1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Opticon USB barcode to serial driver 4 * 5 * Copyright (C) 2011 - 2012 Johan Hovold <jhovold@gmail.com> 6 * Copyright (C) 2011 Martin Jansen <martin.jansen@opticon.com> 7 * Copyright (C) 2008 - 2009 Greg Kroah-Hartman <gregkh@suse.de> 8 * Copyright (C) 2008 - 2009 Novell Inc. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/tty.h> 13 #include <linux/tty_driver.h> 14 #include <linux/slab.h> 15 #include <linux/tty_flip.h> 16 #include <linux/serial.h> 17 #include <linux/module.h> 18 #include <linux/usb.h> 19 #include <linux/usb/serial.h> 20 #include <linux/uaccess.h> 21 22 #define CONTROL_RTS 0x02 23 #define RESEND_CTS_STATE 0x03 24 25 /* max number of write urbs in flight */ 26 #define URB_UPPER_LIMIT 8 27 28 /* This driver works for the Opticon 1D barcode reader 29 * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */ 30 #define DRIVER_DESC "Opticon USB barcode to serial driver (1D)" 31 32 static const struct usb_device_id id_table[] = { 33 { USB_DEVICE(0x065a, 0x0009) }, 34 { }, 35 }; 36 MODULE_DEVICE_TABLE(usb, id_table); 37 38 /* This structure holds all of the individual device information */ 39 struct opticon_private { 40 spinlock_t lock; /* protects the following flags */ 41 bool rts; 42 bool cts; 43 int outstanding_urbs; 44 int outstanding_bytes; 45 46 struct usb_anchor anchor; 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, USB_CTRL_SET_TIMEOUT); 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_close(struct usb_serial_port *port) 156 { 157 struct opticon_private *priv = usb_get_serial_port_data(port); 158 159 usb_kill_anchored_urbs(&priv->anchor); 160 161 usb_serial_generic_close(port); 162 } 163 164 static void opticon_write_control_callback(struct urb *urb) 165 { 166 struct usb_serial_port *port = urb->context; 167 struct opticon_private *priv = usb_get_serial_port_data(port); 168 int status = urb->status; 169 unsigned long flags; 170 171 /* free up the transfer buffer, as usb_free_urb() does not do this */ 172 kfree(urb->transfer_buffer); 173 174 /* setup packet may be set if we're using it for writing */ 175 kfree(urb->setup_packet); 176 177 if (status) 178 dev_dbg(&port->dev, 179 "%s - non-zero urb status received: %d\n", 180 __func__, status); 181 182 spin_lock_irqsave(&priv->lock, flags); 183 --priv->outstanding_urbs; 184 priv->outstanding_bytes -= urb->transfer_buffer_length; 185 spin_unlock_irqrestore(&priv->lock, flags); 186 187 usb_serial_port_softint(port); 188 } 189 190 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, 191 const unsigned char *buf, int count) 192 { 193 struct opticon_private *priv = usb_get_serial_port_data(port); 194 struct usb_serial *serial = port->serial; 195 struct urb *urb; 196 unsigned char *buffer; 197 unsigned long flags; 198 struct usb_ctrlrequest *dr; 199 int ret = -ENOMEM; 200 201 spin_lock_irqsave(&priv->lock, flags); 202 if (priv->outstanding_urbs > URB_UPPER_LIMIT) { 203 spin_unlock_irqrestore(&priv->lock, flags); 204 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 205 return 0; 206 } 207 priv->outstanding_urbs++; 208 priv->outstanding_bytes += count; 209 spin_unlock_irqrestore(&priv->lock, flags); 210 211 buffer = kmemdup(buf, count, GFP_ATOMIC); 212 if (!buffer) 213 goto error_no_buffer; 214 215 urb = usb_alloc_urb(0, GFP_ATOMIC); 216 if (!urb) 217 goto error_no_urb; 218 219 usb_serial_debug_data(&port->dev, __func__, count, buffer); 220 221 /* The connected devices do not have a bulk write endpoint, 222 * to transmit data to de barcode device the control endpoint is used */ 223 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); 224 if (!dr) 225 goto error_no_dr; 226 227 dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; 228 dr->bRequest = 0x01; 229 dr->wValue = 0; 230 dr->wIndex = 0; 231 dr->wLength = cpu_to_le16(count); 232 233 usb_fill_control_urb(urb, serial->dev, 234 usb_sndctrlpipe(serial->dev, 0), 235 (unsigned char *)dr, buffer, count, 236 opticon_write_control_callback, port); 237 238 usb_anchor_urb(urb, &priv->anchor); 239 240 /* send it down the pipe */ 241 ret = usb_submit_urb(urb, GFP_ATOMIC); 242 if (ret) { 243 dev_err(&port->dev, "failed to submit write urb: %d\n", ret); 244 usb_unanchor_urb(urb); 245 goto error; 246 } 247 248 /* we are done with this urb, so let the host driver 249 * really free it when it is finished with it */ 250 usb_free_urb(urb); 251 252 return count; 253 error: 254 kfree(dr); 255 error_no_dr: 256 usb_free_urb(urb); 257 error_no_urb: 258 kfree(buffer); 259 error_no_buffer: 260 spin_lock_irqsave(&priv->lock, flags); 261 --priv->outstanding_urbs; 262 priv->outstanding_bytes -= count; 263 spin_unlock_irqrestore(&priv->lock, flags); 264 265 return ret; 266 } 267 268 static unsigned int opticon_write_room(struct tty_struct *tty) 269 { 270 struct usb_serial_port *port = tty->driver_data; 271 struct opticon_private *priv = usb_get_serial_port_data(port); 272 unsigned long flags; 273 274 /* 275 * We really can take almost anything the user throws at us 276 * but let's pick a nice big number to tell the tty 277 * layer that we have lots of free space, unless we don't. 278 */ 279 spin_lock_irqsave(&priv->lock, flags); 280 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { 281 spin_unlock_irqrestore(&priv->lock, flags); 282 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 283 return 0; 284 } 285 spin_unlock_irqrestore(&priv->lock, flags); 286 287 return 2048; 288 } 289 290 static unsigned int opticon_chars_in_buffer(struct tty_struct *tty) 291 { 292 struct usb_serial_port *port = tty->driver_data; 293 struct opticon_private *priv = usb_get_serial_port_data(port); 294 unsigned long flags; 295 unsigned int count; 296 297 spin_lock_irqsave(&priv->lock, flags); 298 count = priv->outstanding_bytes; 299 spin_unlock_irqrestore(&priv->lock, flags); 300 301 return count; 302 } 303 304 static int opticon_tiocmget(struct tty_struct *tty) 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 int result = 0; 310 311 spin_lock_irqsave(&priv->lock, flags); 312 if (priv->rts) 313 result |= TIOCM_RTS; 314 if (priv->cts) 315 result |= TIOCM_CTS; 316 spin_unlock_irqrestore(&priv->lock, flags); 317 318 dev_dbg(&port->dev, "%s - %x\n", __func__, result); 319 return result; 320 } 321 322 static int opticon_tiocmset(struct tty_struct *tty, 323 unsigned int set, unsigned int clear) 324 { 325 struct usb_serial_port *port = tty->driver_data; 326 struct opticon_private *priv = usb_get_serial_port_data(port); 327 unsigned long flags; 328 bool rts; 329 bool changed = false; 330 int ret; 331 332 /* We only support RTS so we only handle that */ 333 spin_lock_irqsave(&priv->lock, flags); 334 335 rts = priv->rts; 336 if (set & TIOCM_RTS) 337 priv->rts = true; 338 if (clear & TIOCM_RTS) 339 priv->rts = false; 340 changed = rts ^ priv->rts; 341 spin_unlock_irqrestore(&priv->lock, flags); 342 343 if (!changed) 344 return 0; 345 346 ret = send_control_msg(port, CONTROL_RTS, !rts); 347 if (ret) 348 return usb_translate_errors(ret); 349 350 return 0; 351 } 352 353 static int opticon_port_probe(struct usb_serial_port *port) 354 { 355 struct opticon_private *priv; 356 357 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 358 if (!priv) 359 return -ENOMEM; 360 361 spin_lock_init(&priv->lock); 362 init_usb_anchor(&priv->anchor); 363 364 usb_set_serial_port_data(port, priv); 365 366 return 0; 367 } 368 369 static void opticon_port_remove(struct usb_serial_port *port) 370 { 371 struct opticon_private *priv = usb_get_serial_port_data(port); 372 373 kfree(priv); 374 } 375 376 static struct usb_serial_driver opticon_device = { 377 .driver = { 378 .owner = THIS_MODULE, 379 .name = "opticon", 380 }, 381 .id_table = id_table, 382 .num_ports = 1, 383 .num_bulk_in = 1, 384 .bulk_in_size = 256, 385 .port_probe = opticon_port_probe, 386 .port_remove = opticon_port_remove, 387 .open = opticon_open, 388 .close = opticon_close, 389 .write = opticon_write, 390 .write_room = opticon_write_room, 391 .chars_in_buffer = opticon_chars_in_buffer, 392 .throttle = usb_serial_generic_throttle, 393 .unthrottle = usb_serial_generic_unthrottle, 394 .tiocmget = opticon_tiocmget, 395 .tiocmset = opticon_tiocmset, 396 .process_read_urb = opticon_process_read_urb, 397 }; 398 399 static struct usb_serial_driver * const serial_drivers[] = { 400 &opticon_device, NULL 401 }; 402 403 module_usb_serial_driver(serial_drivers, id_table); 404 405 MODULE_DESCRIPTION(DRIVER_DESC); 406 MODULE_LICENSE("GPL v2"); 407