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 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License version 12 * 2 as published by the Free Software Foundation. 13 */ 14 15 #include <linux/kernel.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 if (retval < 0) 124 return retval; 125 126 return 0; 127 } 128 129 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port) 130 { 131 struct opticon_private *priv = usb_get_serial_port_data(port); 132 unsigned long flags; 133 int res; 134 135 spin_lock_irqsave(&priv->lock, flags); 136 priv->rts = false; 137 spin_unlock_irqrestore(&priv->lock, flags); 138 139 /* Clear RTS line */ 140 send_control_msg(port, CONTROL_RTS, 0); 141 142 /* clear the halt status of the endpoint */ 143 usb_clear_halt(port->serial->dev, port->read_urb->pipe); 144 145 res = usb_serial_generic_open(tty, port); 146 if (res) 147 return res; 148 149 /* Request CTS line state, sometimes during opening the current 150 * CTS state can be missed. */ 151 send_control_msg(port, RESEND_CTS_STATE, 1); 152 153 return res; 154 } 155 156 static void opticon_write_control_callback(struct urb *urb) 157 { 158 struct usb_serial_port *port = urb->context; 159 struct opticon_private *priv = usb_get_serial_port_data(port); 160 int status = urb->status; 161 unsigned long flags; 162 163 /* free up the transfer buffer, as usb_free_urb() does not do this */ 164 kfree(urb->transfer_buffer); 165 166 /* setup packet may be set if we're using it for writing */ 167 kfree(urb->setup_packet); 168 169 if (status) 170 dev_dbg(&port->dev, 171 "%s - non-zero urb status received: %d\n", 172 __func__, status); 173 174 spin_lock_irqsave(&priv->lock, flags); 175 --priv->outstanding_urbs; 176 spin_unlock_irqrestore(&priv->lock, flags); 177 178 usb_serial_port_softint(port); 179 } 180 181 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, 182 const unsigned char *buf, int count) 183 { 184 struct opticon_private *priv = usb_get_serial_port_data(port); 185 struct usb_serial *serial = port->serial; 186 struct urb *urb; 187 unsigned char *buffer; 188 unsigned long flags; 189 int status; 190 struct usb_ctrlrequest *dr; 191 192 spin_lock_irqsave(&priv->lock, flags); 193 if (priv->outstanding_urbs > URB_UPPER_LIMIT) { 194 spin_unlock_irqrestore(&priv->lock, flags); 195 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 196 return 0; 197 } 198 priv->outstanding_urbs++; 199 spin_unlock_irqrestore(&priv->lock, flags); 200 201 buffer = kmalloc(count, GFP_ATOMIC); 202 if (!buffer) { 203 count = -ENOMEM; 204 goto error_no_buffer; 205 } 206 207 urb = usb_alloc_urb(0, GFP_ATOMIC); 208 if (!urb) { 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 connected 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_ATOMIC); 220 if (!dr) { 221 count = -ENOMEM; 222 goto error_no_dr; 223 } 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 /* send it down the pipe */ 237 status = usb_submit_urb(urb, GFP_ATOMIC); 238 if (status) { 239 dev_err(&port->dev, 240 "%s - usb_submit_urb(write endpoint) failed status = %d\n", 241 __func__, status); 242 count = status; 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 spin_unlock_irqrestore(&priv->lock, flags); 261 return count; 262 } 263 264 static int opticon_write_room(struct tty_struct *tty) 265 { 266 struct usb_serial_port *port = tty->driver_data; 267 struct opticon_private *priv = usb_get_serial_port_data(port); 268 unsigned long flags; 269 270 /* 271 * We really can take almost anything the user throws at us 272 * but let's pick a nice big number to tell the tty 273 * layer that we have lots of free space, unless we don't. 274 */ 275 spin_lock_irqsave(&priv->lock, flags); 276 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { 277 spin_unlock_irqrestore(&priv->lock, flags); 278 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 279 return 0; 280 } 281 spin_unlock_irqrestore(&priv->lock, flags); 282 283 return 2048; 284 } 285 286 static int opticon_tiocmget(struct tty_struct *tty) 287 { 288 struct usb_serial_port *port = tty->driver_data; 289 struct opticon_private *priv = usb_get_serial_port_data(port); 290 unsigned long flags; 291 int result = 0; 292 293 spin_lock_irqsave(&priv->lock, flags); 294 if (priv->rts) 295 result |= TIOCM_RTS; 296 if (priv->cts) 297 result |= TIOCM_CTS; 298 spin_unlock_irqrestore(&priv->lock, flags); 299 300 dev_dbg(&port->dev, "%s - %x\n", __func__, result); 301 return result; 302 } 303 304 static int opticon_tiocmset(struct tty_struct *tty, 305 unsigned int set, unsigned int clear) 306 { 307 struct usb_serial_port *port = tty->driver_data; 308 struct opticon_private *priv = usb_get_serial_port_data(port); 309 unsigned long flags; 310 bool rts; 311 bool changed = false; 312 int ret; 313 314 /* We only support RTS so we only handle that */ 315 spin_lock_irqsave(&priv->lock, flags); 316 317 rts = priv->rts; 318 if (set & TIOCM_RTS) 319 priv->rts = true; 320 if (clear & TIOCM_RTS) 321 priv->rts = false; 322 changed = rts ^ priv->rts; 323 spin_unlock_irqrestore(&priv->lock, flags); 324 325 if (!changed) 326 return 0; 327 328 ret = send_control_msg(port, CONTROL_RTS, !rts); 329 if (ret) 330 return usb_translate_errors(ret); 331 332 return 0; 333 } 334 335 static int get_serial_info(struct usb_serial_port *port, 336 struct serial_struct __user *serial) 337 { 338 struct serial_struct tmp; 339 340 memset(&tmp, 0x00, sizeof(tmp)); 341 342 /* fake emulate a 16550 uart to make userspace code happy */ 343 tmp.type = PORT_16550A; 344 tmp.line = port->minor; 345 tmp.port = 0; 346 tmp.irq = 0; 347 tmp.xmit_fifo_size = 1024; 348 tmp.baud_base = 9600; 349 tmp.close_delay = 5*HZ; 350 tmp.closing_wait = 30*HZ; 351 352 if (copy_to_user(serial, &tmp, sizeof(*serial))) 353 return -EFAULT; 354 return 0; 355 } 356 357 static int opticon_ioctl(struct tty_struct *tty, 358 unsigned int cmd, unsigned long arg) 359 { 360 struct usb_serial_port *port = tty->driver_data; 361 362 switch (cmd) { 363 case TIOCGSERIAL: 364 return get_serial_info(port, 365 (struct serial_struct __user *)arg); 366 } 367 368 return -ENOIOCTLCMD; 369 } 370 371 static int opticon_port_probe(struct usb_serial_port *port) 372 { 373 struct opticon_private *priv; 374 375 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 376 if (!priv) 377 return -ENOMEM; 378 379 spin_lock_init(&priv->lock); 380 381 usb_set_serial_port_data(port, priv); 382 383 return 0; 384 } 385 386 static int opticon_port_remove(struct usb_serial_port *port) 387 { 388 struct opticon_private *priv = usb_get_serial_port_data(port); 389 390 kfree(priv); 391 392 return 0; 393 } 394 395 static struct usb_serial_driver opticon_device = { 396 .driver = { 397 .owner = THIS_MODULE, 398 .name = "opticon", 399 }, 400 .id_table = id_table, 401 .num_ports = 1, 402 .num_bulk_in = 1, 403 .bulk_in_size = 256, 404 .port_probe = opticon_port_probe, 405 .port_remove = opticon_port_remove, 406 .open = opticon_open, 407 .write = opticon_write, 408 .write_room = opticon_write_room, 409 .throttle = usb_serial_generic_throttle, 410 .unthrottle = usb_serial_generic_unthrottle, 411 .ioctl = opticon_ioctl, 412 .tiocmget = opticon_tiocmget, 413 .tiocmset = opticon_tiocmset, 414 .process_read_urb = opticon_process_read_urb, 415 }; 416 417 static struct usb_serial_driver * const serial_drivers[] = { 418 &opticon_device, NULL 419 }; 420 421 module_usb_serial_driver(serial_drivers, id_table); 422 423 MODULE_DESCRIPTION(DRIVER_DESC); 424 MODULE_LICENSE("GPL"); 425