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/slab.h> 14 #include <linux/tty_flip.h> 15 #include <linux/serial.h> 16 #include <linux/module.h> 17 #include <linux/usb.h> 18 #include <linux/usb/serial.h> 19 20 #define CONTROL_RTS 0x02 21 #define RESEND_CTS_STATE 0x03 22 23 /* max number of write urbs in flight */ 24 #define URB_UPPER_LIMIT 8 25 26 /* This driver works for the Opticon 1D barcode reader 27 * an examples of 1D barcode types are EAN, UPC, Code39, IATA etc.. */ 28 #define DRIVER_DESC "Opticon USB barcode to serial driver (1D)" 29 30 static const struct usb_device_id id_table[] = { 31 { USB_DEVICE(0x065a, 0x0009) }, 32 { }, 33 }; 34 MODULE_DEVICE_TABLE(usb, id_table); 35 36 /* This structure holds all of the individual device information */ 37 struct opticon_private { 38 spinlock_t lock; /* protects the following flags */ 39 bool rts; 40 bool cts; 41 int outstanding_urbs; 42 int outstanding_bytes; 43 44 struct usb_anchor anchor; 45 }; 46 47 48 static void opticon_process_data_packet(struct usb_serial_port *port, 49 const unsigned char *buf, size_t len) 50 { 51 tty_insert_flip_string(&port->port, buf, len); 52 tty_flip_buffer_push(&port->port); 53 } 54 55 static void opticon_process_status_packet(struct usb_serial_port *port, 56 const unsigned char *buf, size_t len) 57 { 58 struct opticon_private *priv = usb_get_serial_port_data(port); 59 unsigned long flags; 60 61 spin_lock_irqsave(&priv->lock, flags); 62 if (buf[0] == 0x00) 63 priv->cts = false; 64 else 65 priv->cts = true; 66 spin_unlock_irqrestore(&priv->lock, flags); 67 } 68 69 static void opticon_process_read_urb(struct urb *urb) 70 { 71 struct usb_serial_port *port = urb->context; 72 const unsigned char *hdr = urb->transfer_buffer; 73 const unsigned char *data = hdr + 2; 74 size_t data_len = urb->actual_length - 2; 75 76 if (urb->actual_length <= 2) { 77 dev_dbg(&port->dev, "malformed packet received: %d bytes\n", 78 urb->actual_length); 79 return; 80 } 81 /* 82 * Data from the device comes with a 2 byte header: 83 * 84 * <0x00><0x00>data... 85 * This is real data to be sent to the tty layer 86 * <0x00><0x01>level 87 * This is a CTS level change, the third byte is the CTS 88 * value (0 for low, 1 for high). 89 */ 90 if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) { 91 opticon_process_data_packet(port, data, data_len); 92 } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) { 93 opticon_process_status_packet(port, data, data_len); 94 } else { 95 dev_dbg(&port->dev, "unknown packet received: %02x %02x\n", 96 hdr[0], hdr[1]); 97 } 98 } 99 100 static int send_control_msg(struct usb_serial_port *port, u8 requesttype, 101 u8 val) 102 { 103 struct usb_serial *serial = port->serial; 104 int retval; 105 u8 *buffer; 106 107 buffer = kzalloc(1, GFP_KERNEL); 108 if (!buffer) 109 return -ENOMEM; 110 111 buffer[0] = val; 112 /* Send the message to the vendor control endpoint 113 * of the connected device */ 114 retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 115 requesttype, 116 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE, 117 0, 0, buffer, 1, USB_CTRL_SET_TIMEOUT); 118 kfree(buffer); 119 120 if (retval < 0) 121 return retval; 122 123 return 0; 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 endpoint */ 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_close(struct usb_serial_port *port) 154 { 155 struct opticon_private *priv = usb_get_serial_port_data(port); 156 157 usb_kill_anchored_urbs(&priv->anchor); 158 159 usb_serial_generic_close(port); 160 } 161 162 static void opticon_write_control_callback(struct urb *urb) 163 { 164 struct usb_serial_port *port = urb->context; 165 struct opticon_private *priv = usb_get_serial_port_data(port); 166 int status = urb->status; 167 unsigned long flags; 168 169 /* free up the transfer buffer, as usb_free_urb() does not do this */ 170 kfree(urb->transfer_buffer); 171 172 /* setup packet may be set if we're using it for writing */ 173 kfree(urb->setup_packet); 174 175 if (status) 176 dev_dbg(&port->dev, 177 "%s - non-zero urb status received: %d\n", 178 __func__, status); 179 180 spin_lock_irqsave(&priv->lock, flags); 181 --priv->outstanding_urbs; 182 priv->outstanding_bytes -= urb->transfer_buffer_length; 183 spin_unlock_irqrestore(&priv->lock, flags); 184 185 usb_serial_port_softint(port); 186 } 187 188 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, 189 const unsigned char *buf, int count) 190 { 191 struct opticon_private *priv = usb_get_serial_port_data(port); 192 struct usb_serial *serial = port->serial; 193 struct urb *urb; 194 unsigned char *buffer; 195 unsigned long flags; 196 struct usb_ctrlrequest *dr; 197 int ret = -ENOMEM; 198 199 spin_lock_irqsave(&priv->lock, flags); 200 if (priv->outstanding_urbs > URB_UPPER_LIMIT) { 201 spin_unlock_irqrestore(&priv->lock, flags); 202 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 203 return 0; 204 } 205 priv->outstanding_urbs++; 206 priv->outstanding_bytes += count; 207 spin_unlock_irqrestore(&priv->lock, flags); 208 209 buffer = kmemdup(buf, count, GFP_ATOMIC); 210 if (!buffer) 211 goto error_no_buffer; 212 213 urb = usb_alloc_urb(0, GFP_ATOMIC); 214 if (!urb) 215 goto error_no_urb; 216 217 usb_serial_debug_data(&port->dev, __func__, count, buffer); 218 219 /* The connected devices do not have a bulk write endpoint, 220 * to transmit data to de barcode device the control endpoint is used */ 221 dr = kmalloc_obj(struct usb_ctrlrequest, GFP_ATOMIC); 222 if (!dr) 223 goto error_no_dr; 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 usb_anchor_urb(urb, &priv->anchor); 237 238 /* send it down the pipe */ 239 ret = usb_submit_urb(urb, GFP_ATOMIC); 240 if (ret) { 241 dev_err(&port->dev, "failed to submit write urb: %d\n", ret); 242 usb_unanchor_urb(urb); 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 priv->outstanding_bytes -= count; 261 spin_unlock_irqrestore(&priv->lock, flags); 262 263 return ret; 264 } 265 266 static unsigned int opticon_write_room(struct tty_struct *tty) 267 { 268 struct usb_serial_port *port = tty->driver_data; 269 struct opticon_private *priv = usb_get_serial_port_data(port); 270 unsigned long flags; 271 272 /* 273 * We really can take almost anything the user throws at us 274 * but let's pick a nice big number to tell the tty 275 * layer that we have lots of free space, unless we don't. 276 */ 277 spin_lock_irqsave(&priv->lock, flags); 278 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { 279 spin_unlock_irqrestore(&priv->lock, flags); 280 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 281 return 0; 282 } 283 spin_unlock_irqrestore(&priv->lock, flags); 284 285 return 2048; 286 } 287 288 static unsigned int opticon_chars_in_buffer(struct tty_struct *tty) 289 { 290 struct usb_serial_port *port = tty->driver_data; 291 struct opticon_private *priv = usb_get_serial_port_data(port); 292 unsigned long flags; 293 unsigned int count; 294 295 spin_lock_irqsave(&priv->lock, flags); 296 count = priv->outstanding_bytes; 297 spin_unlock_irqrestore(&priv->lock, flags); 298 299 return count; 300 } 301 302 static int opticon_tiocmget(struct tty_struct *tty) 303 { 304 struct usb_serial_port *port = tty->driver_data; 305 struct opticon_private *priv = usb_get_serial_port_data(port); 306 unsigned long flags; 307 int result = 0; 308 309 spin_lock_irqsave(&priv->lock, flags); 310 if (priv->rts) 311 result |= TIOCM_RTS; 312 if (priv->cts) 313 result |= TIOCM_CTS; 314 spin_unlock_irqrestore(&priv->lock, flags); 315 316 dev_dbg(&port->dev, "%s - %x\n", __func__, result); 317 return result; 318 } 319 320 static int opticon_tiocmset(struct tty_struct *tty, 321 unsigned int set, unsigned int clear) 322 { 323 struct usb_serial_port *port = tty->driver_data; 324 struct opticon_private *priv = usb_get_serial_port_data(port); 325 unsigned long flags; 326 bool rts; 327 bool changed = false; 328 int ret; 329 330 /* We only support RTS so we only handle that */ 331 spin_lock_irqsave(&priv->lock, flags); 332 333 rts = priv->rts; 334 if (set & TIOCM_RTS) 335 priv->rts = true; 336 if (clear & TIOCM_RTS) 337 priv->rts = false; 338 changed = rts ^ priv->rts; 339 spin_unlock_irqrestore(&priv->lock, flags); 340 341 if (!changed) 342 return 0; 343 344 ret = send_control_msg(port, CONTROL_RTS, !rts); 345 if (ret) 346 return usb_translate_errors(ret); 347 348 return 0; 349 } 350 351 static int opticon_port_probe(struct usb_serial_port *port) 352 { 353 struct opticon_private *priv; 354 355 priv = kzalloc_obj(*priv); 356 if (!priv) 357 return -ENOMEM; 358 359 spin_lock_init(&priv->lock); 360 init_usb_anchor(&priv->anchor); 361 362 usb_set_serial_port_data(port, priv); 363 364 return 0; 365 } 366 367 static void opticon_port_remove(struct usb_serial_port *port) 368 { 369 struct opticon_private *priv = usb_get_serial_port_data(port); 370 371 kfree(priv); 372 } 373 374 static struct usb_serial_driver opticon_device = { 375 .driver = { 376 .name = "opticon", 377 }, 378 .id_table = id_table, 379 .num_ports = 1, 380 .num_bulk_in = 1, 381 .bulk_in_size = 256, 382 .port_probe = opticon_port_probe, 383 .port_remove = opticon_port_remove, 384 .open = opticon_open, 385 .close = opticon_close, 386 .write = opticon_write, 387 .write_room = opticon_write_room, 388 .chars_in_buffer = opticon_chars_in_buffer, 389 .throttle = usb_serial_generic_throttle, 390 .unthrottle = usb_serial_generic_unthrottle, 391 .tiocmget = opticon_tiocmget, 392 .tiocmset = opticon_tiocmset, 393 .process_read_urb = opticon_process_read_urb, 394 }; 395 396 static struct usb_serial_driver * const serial_drivers[] = { 397 &opticon_device, NULL 398 }; 399 400 module_usb_serial_driver(serial_drivers, id_table); 401 402 MODULE_DESCRIPTION(DRIVER_DESC); 403 MODULE_LICENSE("GPL v2"); 404