1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * USB IR Dongle driver 4 * 5 * Copyright (C) 2001-2002 Greg Kroah-Hartman (greg@kroah.com) 6 * Copyright (C) 2002 Gary Brubaker (xavyer@ix.netcom.com) 7 * Copyright (C) 2010 Johan Hovold (jhovold@gmail.com) 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This driver allows a USB IrDA device to be used as a "dumb" serial device. 15 * This can be useful if you do not have access to a full IrDA stack on the 16 * other side of the connection. If you do have an IrDA stack on both devices, 17 * please use the usb-irda driver, as it contains the proper error checking and 18 * other goodness of a full IrDA stack. 19 * 20 * Portions of this driver were taken from drivers/net/irda/irda-usb.c, which 21 * was written by Roman Weissgaerber <weissg@vienna.at>, Dag Brattli 22 * <dag@brattli.net>, and Jean Tourrilhes <jt@hpl.hp.com> 23 * 24 * See Documentation/usb/usb-serial.txt for more information on using this 25 * driver 26 */ 27 28 #include <linux/kernel.h> 29 #include <linux/errno.h> 30 #include <linux/init.h> 31 #include <linux/slab.h> 32 #include <linux/tty.h> 33 #include <linux/tty_driver.h> 34 #include <linux/tty_flip.h> 35 #include <linux/module.h> 36 #include <linux/spinlock.h> 37 #include <linux/uaccess.h> 38 #include <linux/usb.h> 39 #include <linux/usb/serial.h> 40 #include <linux/usb/irda.h> 41 42 #define DRIVER_AUTHOR "Greg Kroah-Hartman <greg@kroah.com>, Johan Hovold <jhovold@gmail.com>" 43 #define DRIVER_DESC "USB IR Dongle driver" 44 45 /* if overridden by the user, then use their value for the size of the read and 46 * write urbs */ 47 static int buffer_size; 48 49 /* if overridden by the user, then use the specified number of XBOFs */ 50 static int xbof = -1; 51 52 static int ir_startup (struct usb_serial *serial); 53 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port); 54 static int ir_prepare_write_buffer(struct usb_serial_port *port, 55 void *dest, size_t size); 56 static void ir_process_read_urb(struct urb *urb); 57 static void ir_set_termios(struct tty_struct *tty, 58 struct usb_serial_port *port, struct ktermios *old_termios); 59 60 /* Not that this lot means you can only have one per system */ 61 static u8 ir_baud; 62 static u8 ir_xbof; 63 static u8 ir_add_bof; 64 65 static const struct usb_device_id ir_id_table[] = { 66 { USB_DEVICE(0x050f, 0x0180) }, /* KC Technology, KC-180 */ 67 { USB_DEVICE(0x08e9, 0x0100) }, /* XTNDAccess */ 68 { USB_DEVICE(0x09c4, 0x0011) }, /* ACTiSys ACT-IR2000U */ 69 { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, USB_SUBCLASS_IRDA, 0) }, 70 { } /* Terminating entry */ 71 }; 72 73 MODULE_DEVICE_TABLE(usb, ir_id_table); 74 75 static struct usb_serial_driver ir_device = { 76 .driver = { 77 .owner = THIS_MODULE, 78 .name = "ir-usb", 79 }, 80 .description = "IR Dongle", 81 .id_table = ir_id_table, 82 .num_ports = 1, 83 .set_termios = ir_set_termios, 84 .attach = ir_startup, 85 .open = ir_open, 86 .prepare_write_buffer = ir_prepare_write_buffer, 87 .process_read_urb = ir_process_read_urb, 88 }; 89 90 static struct usb_serial_driver * const serial_drivers[] = { 91 &ir_device, NULL 92 }; 93 94 static inline void irda_usb_dump_class_desc(struct usb_serial *serial, 95 struct usb_irda_cs_descriptor *desc) 96 { 97 struct device *dev = &serial->dev->dev; 98 99 dev_dbg(dev, "bLength=%x\n", desc->bLength); 100 dev_dbg(dev, "bDescriptorType=%x\n", desc->bDescriptorType); 101 dev_dbg(dev, "bcdSpecRevision=%x\n", __le16_to_cpu(desc->bcdSpecRevision)); 102 dev_dbg(dev, "bmDataSize=%x\n", desc->bmDataSize); 103 dev_dbg(dev, "bmWindowSize=%x\n", desc->bmWindowSize); 104 dev_dbg(dev, "bmMinTurnaroundTime=%d\n", desc->bmMinTurnaroundTime); 105 dev_dbg(dev, "wBaudRate=%x\n", __le16_to_cpu(desc->wBaudRate)); 106 dev_dbg(dev, "bmAdditionalBOFs=%x\n", desc->bmAdditionalBOFs); 107 dev_dbg(dev, "bIrdaRateSniff=%x\n", desc->bIrdaRateSniff); 108 dev_dbg(dev, "bMaxUnicastList=%x\n", desc->bMaxUnicastList); 109 } 110 111 /*------------------------------------------------------------------*/ 112 /* 113 * Function irda_usb_find_class_desc(dev, ifnum) 114 * 115 * Returns instance of IrDA class descriptor, or NULL if not found 116 * 117 * The class descriptor is some extra info that IrDA USB devices will 118 * offer to us, describing their IrDA characteristics. We will use that in 119 * irda_usb_init_qos() 120 * 121 * Based on the same function in drivers/net/irda/irda-usb.c 122 */ 123 static struct usb_irda_cs_descriptor * 124 irda_usb_find_class_desc(struct usb_serial *serial, unsigned int ifnum) 125 { 126 struct usb_device *dev = serial->dev; 127 struct usb_irda_cs_descriptor *desc; 128 int ret; 129 130 desc = kzalloc(sizeof(*desc), GFP_KERNEL); 131 if (!desc) 132 return NULL; 133 134 ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), 135 USB_REQ_CS_IRDA_GET_CLASS_DESC, 136 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE, 137 0, ifnum, desc, sizeof(*desc), 1000); 138 139 dev_dbg(&serial->dev->dev, "%s - ret=%d\n", __func__, ret); 140 if (ret < sizeof(*desc)) { 141 dev_dbg(&serial->dev->dev, 142 "%s - class descriptor read %s (%d)\n", __func__, 143 (ret < 0) ? "failed" : "too short", ret); 144 goto error; 145 } 146 if (desc->bDescriptorType != USB_DT_CS_IRDA) { 147 dev_dbg(&serial->dev->dev, "%s - bad class descriptor type\n", 148 __func__); 149 goto error; 150 } 151 152 irda_usb_dump_class_desc(serial, desc); 153 return desc; 154 155 error: 156 kfree(desc); 157 return NULL; 158 } 159 160 static u8 ir_xbof_change(u8 xbof) 161 { 162 u8 result; 163 164 /* reference irda-usb.c */ 165 switch (xbof) { 166 case 48: 167 result = 0x10; 168 break; 169 case 28: 170 case 24: 171 result = 0x20; 172 break; 173 default: 174 case 12: 175 result = 0x30; 176 break; 177 case 5: 178 case 6: 179 result = 0x40; 180 break; 181 case 3: 182 result = 0x50; 183 break; 184 case 2: 185 result = 0x60; 186 break; 187 case 1: 188 result = 0x70; 189 break; 190 case 0: 191 result = 0x80; 192 break; 193 } 194 195 return(result); 196 } 197 198 static int ir_startup(struct usb_serial *serial) 199 { 200 struct usb_irda_cs_descriptor *irda_desc; 201 int rates; 202 203 irda_desc = irda_usb_find_class_desc(serial, 0); 204 if (!irda_desc) { 205 dev_err(&serial->dev->dev, 206 "IRDA class descriptor not found, device not bound\n"); 207 return -ENODEV; 208 } 209 210 rates = le16_to_cpu(irda_desc->wBaudRate); 211 212 dev_dbg(&serial->dev->dev, 213 "%s - Baud rates supported:%s%s%s%s%s%s%s%s%s\n", 214 __func__, 215 (rates & USB_IRDA_BR_2400) ? " 2400" : "", 216 (rates & USB_IRDA_BR_9600) ? " 9600" : "", 217 (rates & USB_IRDA_BR_19200) ? " 19200" : "", 218 (rates & USB_IRDA_BR_38400) ? " 38400" : "", 219 (rates & USB_IRDA_BR_57600) ? " 57600" : "", 220 (rates & USB_IRDA_BR_115200) ? " 115200" : "", 221 (rates & USB_IRDA_BR_576000) ? " 576000" : "", 222 (rates & USB_IRDA_BR_1152000) ? " 1152000" : "", 223 (rates & USB_IRDA_BR_4000000) ? " 4000000" : ""); 224 225 switch (irda_desc->bmAdditionalBOFs) { 226 case USB_IRDA_AB_48: 227 ir_add_bof = 48; 228 break; 229 case USB_IRDA_AB_24: 230 ir_add_bof = 24; 231 break; 232 case USB_IRDA_AB_12: 233 ir_add_bof = 12; 234 break; 235 case USB_IRDA_AB_6: 236 ir_add_bof = 6; 237 break; 238 case USB_IRDA_AB_3: 239 ir_add_bof = 3; 240 break; 241 case USB_IRDA_AB_2: 242 ir_add_bof = 2; 243 break; 244 case USB_IRDA_AB_1: 245 ir_add_bof = 1; 246 break; 247 case USB_IRDA_AB_0: 248 ir_add_bof = 0; 249 break; 250 default: 251 break; 252 } 253 254 kfree(irda_desc); 255 256 return 0; 257 } 258 259 static int ir_open(struct tty_struct *tty, struct usb_serial_port *port) 260 { 261 int i; 262 263 for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) 264 port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET; 265 266 /* Start reading from the device */ 267 return usb_serial_generic_open(tty, port); 268 } 269 270 static int ir_prepare_write_buffer(struct usb_serial_port *port, 271 void *dest, size_t size) 272 { 273 unsigned char *buf = dest; 274 int count; 275 276 /* 277 * The first byte of the packet we send to the device contains an 278 * inbound header which indicates an additional number of BOFs and 279 * a baud rate change. 280 * 281 * See section 5.4.2.2 of the USB IrDA spec. 282 */ 283 *buf = ir_xbof | ir_baud; 284 285 count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1, 286 &port->lock); 287 return count + 1; 288 } 289 290 static void ir_process_read_urb(struct urb *urb) 291 { 292 struct usb_serial_port *port = urb->context; 293 unsigned char *data = urb->transfer_buffer; 294 295 if (!urb->actual_length) 296 return; 297 /* 298 * The first byte of the packet we get from the device 299 * contains a busy indicator and baud rate change. 300 * See section 5.4.1.2 of the USB IrDA spec. 301 */ 302 if (*data & 0x0f) 303 ir_baud = *data & 0x0f; 304 305 if (urb->actual_length == 1) 306 return; 307 308 tty_insert_flip_string(&port->port, data + 1, urb->actual_length - 1); 309 tty_flip_buffer_push(&port->port); 310 } 311 312 static void ir_set_termios_callback(struct urb *urb) 313 { 314 kfree(urb->transfer_buffer); 315 316 if (urb->status) 317 dev_dbg(&urb->dev->dev, "%s - non-zero urb status: %d\n", 318 __func__, urb->status); 319 } 320 321 static void ir_set_termios(struct tty_struct *tty, 322 struct usb_serial_port *port, struct ktermios *old_termios) 323 { 324 struct urb *urb; 325 unsigned char *transfer_buffer; 326 int result; 327 speed_t baud; 328 int ir_baud; 329 330 baud = tty_get_baud_rate(tty); 331 332 /* 333 * FIXME, we should compare the baud request against the 334 * capability stated in the IR header that we got in the 335 * startup function. 336 */ 337 338 switch (baud) { 339 case 2400: 340 ir_baud = USB_IRDA_BR_2400; 341 break; 342 case 9600: 343 ir_baud = USB_IRDA_BR_9600; 344 break; 345 case 19200: 346 ir_baud = USB_IRDA_BR_19200; 347 break; 348 case 38400: 349 ir_baud = USB_IRDA_BR_38400; 350 break; 351 case 57600: 352 ir_baud = USB_IRDA_BR_57600; 353 break; 354 case 115200: 355 ir_baud = USB_IRDA_BR_115200; 356 break; 357 case 576000: 358 ir_baud = USB_IRDA_BR_576000; 359 break; 360 case 1152000: 361 ir_baud = USB_IRDA_BR_1152000; 362 break; 363 case 4000000: 364 ir_baud = USB_IRDA_BR_4000000; 365 break; 366 default: 367 ir_baud = USB_IRDA_BR_9600; 368 baud = 9600; 369 } 370 371 if (xbof == -1) 372 ir_xbof = ir_xbof_change(ir_add_bof); 373 else 374 ir_xbof = ir_xbof_change(xbof) ; 375 376 /* Only speed changes are supported */ 377 tty_termios_copy_hw(&tty->termios, old_termios); 378 tty_encode_baud_rate(tty, baud, baud); 379 380 /* 381 * send the baud change out on an "empty" data packet 382 */ 383 urb = usb_alloc_urb(0, GFP_KERNEL); 384 if (!urb) 385 return; 386 387 transfer_buffer = kmalloc(1, GFP_KERNEL); 388 if (!transfer_buffer) 389 goto err_buf; 390 391 *transfer_buffer = ir_xbof | ir_baud; 392 393 usb_fill_bulk_urb( 394 urb, 395 port->serial->dev, 396 usb_sndbulkpipe(port->serial->dev, 397 port->bulk_out_endpointAddress), 398 transfer_buffer, 399 1, 400 ir_set_termios_callback, 401 port); 402 403 urb->transfer_flags = URB_ZERO_PACKET; 404 405 result = usb_submit_urb(urb, GFP_KERNEL); 406 if (result) { 407 dev_err(&port->dev, "%s - failed to submit urb: %d\n", 408 __func__, result); 409 goto err_subm; 410 } 411 412 usb_free_urb(urb); 413 414 return; 415 err_subm: 416 kfree(transfer_buffer); 417 err_buf: 418 usb_free_urb(urb); 419 } 420 421 static int __init ir_init(void) 422 { 423 if (buffer_size) { 424 ir_device.bulk_in_size = buffer_size; 425 ir_device.bulk_out_size = buffer_size; 426 } 427 428 return usb_serial_register_drivers(serial_drivers, KBUILD_MODNAME, ir_id_table); 429 } 430 431 static void __exit ir_exit(void) 432 { 433 usb_serial_deregister_drivers(serial_drivers); 434 } 435 436 437 module_init(ir_init); 438 module_exit(ir_exit); 439 440 MODULE_AUTHOR(DRIVER_AUTHOR); 441 MODULE_DESCRIPTION(DRIVER_DESC); 442 MODULE_LICENSE("GPL"); 443 444 module_param(xbof, int, 0); 445 MODULE_PARM_DESC(xbof, "Force specific number of XBOFs"); 446 module_param(buffer_size, int, 0); 447 MODULE_PARM_DESC(buffer_size, "Size of the transfer buffers"); 448 449