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 }; 45 46 47 static void opticon_process_data_packet(struct usb_serial_port *port, 48 const unsigned char *buf, size_t len) 49 { 50 tty_insert_flip_string(&port->port, buf, len); 51 tty_flip_buffer_push(&port->port); 52 } 53 54 static void opticon_process_status_packet(struct usb_serial_port *port, 55 const unsigned char *buf, size_t len) 56 { 57 struct opticon_private *priv = usb_get_serial_port_data(port); 58 unsigned long flags; 59 60 spin_lock_irqsave(&priv->lock, flags); 61 if (buf[0] == 0x00) 62 priv->cts = false; 63 else 64 priv->cts = true; 65 spin_unlock_irqrestore(&priv->lock, flags); 66 } 67 68 static void opticon_process_read_urb(struct urb *urb) 69 { 70 struct usb_serial_port *port = urb->context; 71 const unsigned char *hdr = urb->transfer_buffer; 72 const unsigned char *data = hdr + 2; 73 size_t data_len = urb->actual_length - 2; 74 75 if (urb->actual_length <= 2) { 76 dev_dbg(&port->dev, "malformed packet received: %d bytes\n", 77 urb->actual_length); 78 return; 79 } 80 /* 81 * Data from the device comes with a 2 byte header: 82 * 83 * <0x00><0x00>data... 84 * This is real data to be sent to the tty layer 85 * <0x00><0x01>level 86 * This is a CTS level change, the third byte is the CTS 87 * value (0 for low, 1 for high). 88 */ 89 if ((hdr[0] == 0x00) && (hdr[1] == 0x00)) { 90 opticon_process_data_packet(port, data, data_len); 91 } else if ((hdr[0] == 0x00) && (hdr[1] == 0x01)) { 92 opticon_process_status_packet(port, data, data_len); 93 } else { 94 dev_dbg(&port->dev, "unknown packet received: %02x %02x\n", 95 hdr[0], hdr[1]); 96 } 97 } 98 99 static int send_control_msg(struct usb_serial_port *port, u8 requesttype, 100 u8 val) 101 { 102 struct usb_serial *serial = port->serial; 103 int retval; 104 u8 *buffer; 105 106 buffer = kzalloc(1, GFP_KERNEL); 107 if (!buffer) 108 return -ENOMEM; 109 110 buffer[0] = val; 111 /* Send the message to the vendor control endpoint 112 * of the connected device */ 113 retval = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0), 114 requesttype, 115 USB_DIR_OUT|USB_TYPE_VENDOR|USB_RECIP_INTERFACE, 116 0, 0, buffer, 1, 0); 117 kfree(buffer); 118 119 if (retval < 0) 120 return retval; 121 122 return 0; 123 } 124 125 static int opticon_open(struct tty_struct *tty, struct usb_serial_port *port) 126 { 127 struct opticon_private *priv = usb_get_serial_port_data(port); 128 unsigned long flags; 129 int res; 130 131 spin_lock_irqsave(&priv->lock, flags); 132 priv->rts = false; 133 spin_unlock_irqrestore(&priv->lock, flags); 134 135 /* Clear RTS line */ 136 send_control_msg(port, CONTROL_RTS, 0); 137 138 /* clear the halt status of the endpoint */ 139 usb_clear_halt(port->serial->dev, port->read_urb->pipe); 140 141 res = usb_serial_generic_open(tty, port); 142 if (res) 143 return res; 144 145 /* Request CTS line state, sometimes during opening the current 146 * CTS state can be missed. */ 147 send_control_msg(port, RESEND_CTS_STATE, 1); 148 149 return res; 150 } 151 152 static void opticon_write_control_callback(struct urb *urb) 153 { 154 struct usb_serial_port *port = urb->context; 155 struct opticon_private *priv = usb_get_serial_port_data(port); 156 int status = urb->status; 157 unsigned long flags; 158 159 /* free up the transfer buffer, as usb_free_urb() does not do this */ 160 kfree(urb->transfer_buffer); 161 162 /* setup packet may be set if we're using it for writing */ 163 kfree(urb->setup_packet); 164 165 if (status) 166 dev_dbg(&port->dev, 167 "%s - non-zero urb status received: %d\n", 168 __func__, status); 169 170 spin_lock_irqsave(&priv->lock, flags); 171 --priv->outstanding_urbs; 172 spin_unlock_irqrestore(&priv->lock, flags); 173 174 usb_serial_port_softint(port); 175 } 176 177 static int opticon_write(struct tty_struct *tty, struct usb_serial_port *port, 178 const unsigned char *buf, int count) 179 { 180 struct opticon_private *priv = usb_get_serial_port_data(port); 181 struct usb_serial *serial = port->serial; 182 struct urb *urb; 183 unsigned char *buffer; 184 unsigned long flags; 185 int status; 186 struct usb_ctrlrequest *dr; 187 188 spin_lock_irqsave(&priv->lock, flags); 189 if (priv->outstanding_urbs > URB_UPPER_LIMIT) { 190 spin_unlock_irqrestore(&priv->lock, flags); 191 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 192 return 0; 193 } 194 priv->outstanding_urbs++; 195 spin_unlock_irqrestore(&priv->lock, flags); 196 197 buffer = kmalloc(count, GFP_ATOMIC); 198 if (!buffer) { 199 count = -ENOMEM; 200 goto error_no_buffer; 201 } 202 203 urb = usb_alloc_urb(0, GFP_ATOMIC); 204 if (!urb) { 205 count = -ENOMEM; 206 goto error_no_urb; 207 } 208 209 memcpy(buffer, buf, count); 210 211 usb_serial_debug_data(&port->dev, __func__, count, buffer); 212 213 /* The connected devices do not have a bulk write endpoint, 214 * to transmit data to de barcode device the control endpoint is used */ 215 dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_ATOMIC); 216 if (!dr) { 217 count = -ENOMEM; 218 goto error_no_dr; 219 } 220 221 dr->bRequestType = USB_TYPE_VENDOR | USB_RECIP_INTERFACE | USB_DIR_OUT; 222 dr->bRequest = 0x01; 223 dr->wValue = 0; 224 dr->wIndex = 0; 225 dr->wLength = cpu_to_le16(count); 226 227 usb_fill_control_urb(urb, serial->dev, 228 usb_sndctrlpipe(serial->dev, 0), 229 (unsigned char *)dr, buffer, count, 230 opticon_write_control_callback, port); 231 232 /* send it down the pipe */ 233 status = usb_submit_urb(urb, GFP_ATOMIC); 234 if (status) { 235 dev_err(&port->dev, 236 "%s - usb_submit_urb(write endpoint) failed status = %d\n", 237 __func__, status); 238 count = status; 239 goto error; 240 } 241 242 /* we are done with this urb, so let the host driver 243 * really free it when it is finished with it */ 244 usb_free_urb(urb); 245 246 return count; 247 error: 248 kfree(dr); 249 error_no_dr: 250 usb_free_urb(urb); 251 error_no_urb: 252 kfree(buffer); 253 error_no_buffer: 254 spin_lock_irqsave(&priv->lock, flags); 255 --priv->outstanding_urbs; 256 spin_unlock_irqrestore(&priv->lock, flags); 257 return count; 258 } 259 260 static int opticon_write_room(struct tty_struct *tty) 261 { 262 struct usb_serial_port *port = tty->driver_data; 263 struct opticon_private *priv = usb_get_serial_port_data(port); 264 unsigned long flags; 265 266 /* 267 * We really can take almost anything the user throws at us 268 * but let's pick a nice big number to tell the tty 269 * layer that we have lots of free space, unless we don't. 270 */ 271 spin_lock_irqsave(&priv->lock, flags); 272 if (priv->outstanding_urbs > URB_UPPER_LIMIT * 2 / 3) { 273 spin_unlock_irqrestore(&priv->lock, flags); 274 dev_dbg(&port->dev, "%s - write limit hit\n", __func__); 275 return 0; 276 } 277 spin_unlock_irqrestore(&priv->lock, flags); 278 279 return 2048; 280 } 281 282 static int opticon_tiocmget(struct tty_struct *tty) 283 { 284 struct usb_serial_port *port = tty->driver_data; 285 struct opticon_private *priv = usb_get_serial_port_data(port); 286 unsigned long flags; 287 int result = 0; 288 289 spin_lock_irqsave(&priv->lock, flags); 290 if (priv->rts) 291 result |= TIOCM_RTS; 292 if (priv->cts) 293 result |= TIOCM_CTS; 294 spin_unlock_irqrestore(&priv->lock, flags); 295 296 dev_dbg(&port->dev, "%s - %x\n", __func__, result); 297 return result; 298 } 299 300 static int opticon_tiocmset(struct tty_struct *tty, 301 unsigned int set, unsigned int clear) 302 { 303 struct usb_serial_port *port = tty->driver_data; 304 struct opticon_private *priv = usb_get_serial_port_data(port); 305 unsigned long flags; 306 bool rts; 307 bool changed = false; 308 int ret; 309 310 /* We only support RTS so we only handle that */ 311 spin_lock_irqsave(&priv->lock, flags); 312 313 rts = priv->rts; 314 if (set & TIOCM_RTS) 315 priv->rts = true; 316 if (clear & TIOCM_RTS) 317 priv->rts = false; 318 changed = rts ^ priv->rts; 319 spin_unlock_irqrestore(&priv->lock, flags); 320 321 if (!changed) 322 return 0; 323 324 ret = send_control_msg(port, CONTROL_RTS, !rts); 325 if (ret) 326 return usb_translate_errors(ret); 327 328 return 0; 329 } 330 331 static int get_serial_info(struct usb_serial_port *port, 332 struct serial_struct __user *serial) 333 { 334 struct serial_struct tmp; 335 336 memset(&tmp, 0x00, sizeof(tmp)); 337 338 /* fake emulate a 16550 uart to make userspace code happy */ 339 tmp.type = PORT_16550A; 340 tmp.line = port->minor; 341 tmp.port = 0; 342 tmp.irq = 0; 343 tmp.xmit_fifo_size = 1024; 344 tmp.baud_base = 9600; 345 tmp.close_delay = 5*HZ; 346 tmp.closing_wait = 30*HZ; 347 348 if (copy_to_user(serial, &tmp, sizeof(*serial))) 349 return -EFAULT; 350 return 0; 351 } 352 353 static int opticon_ioctl(struct tty_struct *tty, 354 unsigned int cmd, unsigned long arg) 355 { 356 struct usb_serial_port *port = tty->driver_data; 357 358 switch (cmd) { 359 case TIOCGSERIAL: 360 return get_serial_info(port, 361 (struct serial_struct __user *)arg); 362 } 363 364 return -ENOIOCTLCMD; 365 } 366 367 static int opticon_port_probe(struct usb_serial_port *port) 368 { 369 struct opticon_private *priv; 370 371 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 372 if (!priv) 373 return -ENOMEM; 374 375 spin_lock_init(&priv->lock); 376 377 usb_set_serial_port_data(port, priv); 378 379 return 0; 380 } 381 382 static int opticon_port_remove(struct usb_serial_port *port) 383 { 384 struct opticon_private *priv = usb_get_serial_port_data(port); 385 386 kfree(priv); 387 388 return 0; 389 } 390 391 static struct usb_serial_driver opticon_device = { 392 .driver = { 393 .owner = THIS_MODULE, 394 .name = "opticon", 395 }, 396 .id_table = id_table, 397 .num_ports = 1, 398 .num_bulk_in = 1, 399 .bulk_in_size = 256, 400 .port_probe = opticon_port_probe, 401 .port_remove = opticon_port_remove, 402 .open = opticon_open, 403 .write = opticon_write, 404 .write_room = opticon_write_room, 405 .throttle = usb_serial_generic_throttle, 406 .unthrottle = usb_serial_generic_unthrottle, 407 .ioctl = opticon_ioctl, 408 .tiocmget = opticon_tiocmget, 409 .tiocmset = opticon_tiocmset, 410 .process_read_urb = opticon_process_read_urb, 411 }; 412 413 static struct usb_serial_driver * const serial_drivers[] = { 414 &opticon_device, NULL 415 }; 416 417 module_usb_serial_driver(serial_drivers, id_table); 418 419 MODULE_DESCRIPTION(DRIVER_DESC); 420 MODULE_LICENSE("GPL v2"); 421