1 /* 2 * Copyright (C) 2009 by Bart Hartgers (bart.hartgers+ark3116@gmail.com) 3 * Original version: 4 * Copyright (C) 2006 5 * Simon Schulz (ark3116_driver <at> auctionant.de) 6 * 7 * ark3116 8 * - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547, 9 * productid=0x0232) (used in a datacable called KQ-U8A) 10 * 11 * Supports full modem status lines, break, hardware flow control. Does not 12 * support software flow control, since I do not know how to enable it in hw. 13 * 14 * This driver is a essentially new implementation. I initially dug 15 * into the old ark3116.c driver and suddenly realized the ark3116 is 16 * a 16450 with a USB interface glued to it. See comments at the 17 * bottom of this file. 18 * 19 * This program is free software; you can redistribute it and/or modify it 20 * under the terms of the GNU General Public License as published by the 21 * Free Software Foundation; either version 2 of the License, or (at your 22 * option) any later version. 23 */ 24 25 #include <linux/kernel.h> 26 #include <linux/init.h> 27 #include <linux/ioctl.h> 28 #include <linux/tty.h> 29 #include <linux/slab.h> 30 #include <linux/tty_flip.h> 31 #include <linux/module.h> 32 #include <linux/usb.h> 33 #include <linux/usb/serial.h> 34 #include <linux/serial.h> 35 #include <linux/serial_reg.h> 36 #include <linux/uaccess.h> 37 #include <linux/mutex.h> 38 #include <linux/spinlock.h> 39 40 #define DRIVER_AUTHOR "Bart Hartgers <bart.hartgers+ark3116@gmail.com>" 41 #define DRIVER_DESC "USB ARK3116 serial/IrDA driver" 42 #define DRIVER_DEV_DESC "ARK3116 RS232/IrDA" 43 #define DRIVER_NAME "ark3116" 44 45 /* usb timeout of 1 second */ 46 #define ARK_TIMEOUT (1*HZ) 47 48 static const struct usb_device_id id_table[] = { 49 { USB_DEVICE(0x6547, 0x0232) }, 50 { USB_DEVICE(0x18ec, 0x3118) }, /* USB to IrDA adapter */ 51 { }, 52 }; 53 MODULE_DEVICE_TABLE(usb, id_table); 54 55 static int is_irda(struct usb_serial *serial) 56 { 57 struct usb_device *dev = serial->dev; 58 if (le16_to_cpu(dev->descriptor.idVendor) == 0x18ec && 59 le16_to_cpu(dev->descriptor.idProduct) == 0x3118) 60 return 1; 61 return 0; 62 } 63 64 struct ark3116_private { 65 struct async_icount icount; 66 int irda; /* 1 for irda device */ 67 68 /* protects hw register updates */ 69 struct mutex hw_lock; 70 71 int quot; /* baudrate divisor */ 72 __u32 lcr; /* line control register value */ 73 __u32 hcr; /* handshake control register (0x8) 74 * value */ 75 __u32 mcr; /* modem contol register value */ 76 77 /* protects the status values below */ 78 spinlock_t status_lock; 79 __u32 msr; /* modem status register value */ 80 __u32 lsr; /* line status register value */ 81 }; 82 83 static int ark3116_write_reg(struct usb_serial *serial, 84 unsigned reg, __u8 val) 85 { 86 int result; 87 /* 0xfe 0x40 are magic values taken from original driver */ 88 result = usb_control_msg(serial->dev, 89 usb_sndctrlpipe(serial->dev, 0), 90 0xfe, 0x40, val, reg, 91 NULL, 0, ARK_TIMEOUT); 92 return result; 93 } 94 95 static int ark3116_read_reg(struct usb_serial *serial, 96 unsigned reg, unsigned char *buf) 97 { 98 int result; 99 /* 0xfe 0xc0 are magic values taken from original driver */ 100 result = usb_control_msg(serial->dev, 101 usb_rcvctrlpipe(serial->dev, 0), 102 0xfe, 0xc0, 0, reg, 103 buf, 1, ARK_TIMEOUT); 104 if (result < 0) 105 return result; 106 else 107 return buf[0]; 108 } 109 110 static inline int calc_divisor(int bps) 111 { 112 /* Original ark3116 made some exceptions in rounding here 113 * because windows did the same. Assume that is not really 114 * necessary. 115 * Crystal is 12MHz, probably because of USB, but we divide by 4? 116 */ 117 return (12000000 + 2*bps) / (4*bps); 118 } 119 120 static int ark3116_attach(struct usb_serial *serial) 121 { 122 /* make sure we have our end-points */ 123 if ((serial->num_bulk_in == 0) || 124 (serial->num_bulk_out == 0) || 125 (serial->num_interrupt_in == 0)) { 126 dev_err(&serial->dev->dev, 127 "%s - missing endpoint - " 128 "bulk in: %d, bulk out: %d, int in %d\n", 129 KBUILD_MODNAME, 130 serial->num_bulk_in, 131 serial->num_bulk_out, 132 serial->num_interrupt_in); 133 return -EINVAL; 134 } 135 136 return 0; 137 } 138 139 static int ark3116_port_probe(struct usb_serial_port *port) 140 { 141 struct usb_serial *serial = port->serial; 142 struct ark3116_private *priv; 143 144 priv = kzalloc(sizeof(*priv), GFP_KERNEL); 145 if (!priv) 146 return -ENOMEM; 147 148 mutex_init(&priv->hw_lock); 149 spin_lock_init(&priv->status_lock); 150 151 priv->irda = is_irda(serial); 152 153 usb_set_serial_port_data(port, priv); 154 155 /* setup the hardware */ 156 ark3116_write_reg(serial, UART_IER, 0); 157 /* disable DMA */ 158 ark3116_write_reg(serial, UART_FCR, 0); 159 /* handshake control */ 160 priv->hcr = 0; 161 ark3116_write_reg(serial, 0x8 , 0); 162 /* modem control */ 163 priv->mcr = 0; 164 ark3116_write_reg(serial, UART_MCR, 0); 165 166 if (!(priv->irda)) { 167 ark3116_write_reg(serial, 0xb , 0); 168 } else { 169 ark3116_write_reg(serial, 0xb , 1); 170 ark3116_write_reg(serial, 0xc , 0); 171 ark3116_write_reg(serial, 0xd , 0x41); 172 ark3116_write_reg(serial, 0xa , 1); 173 } 174 175 /* setup baudrate */ 176 ark3116_write_reg(serial, UART_LCR, UART_LCR_DLAB); 177 178 /* setup for 9600 8N1 */ 179 priv->quot = calc_divisor(9600); 180 ark3116_write_reg(serial, UART_DLL, priv->quot & 0xff); 181 ark3116_write_reg(serial, UART_DLM, (priv->quot>>8) & 0xff); 182 183 priv->lcr = UART_LCR_WLEN8; 184 ark3116_write_reg(serial, UART_LCR, UART_LCR_WLEN8); 185 186 ark3116_write_reg(serial, 0xe, 0); 187 188 if (priv->irda) 189 ark3116_write_reg(serial, 0x9, 0); 190 191 dev_info(&serial->dev->dev, 192 "%s using %s mode\n", 193 KBUILD_MODNAME, 194 priv->irda ? "IrDA" : "RS232"); 195 return 0; 196 } 197 198 static int ark3116_port_remove(struct usb_serial_port *port) 199 { 200 struct ark3116_private *priv = usb_get_serial_port_data(port); 201 202 /* device is closed, so URBs and DMA should be down */ 203 mutex_destroy(&priv->hw_lock); 204 kfree(priv); 205 206 return 0; 207 } 208 209 static void ark3116_init_termios(struct tty_struct *tty) 210 { 211 struct ktermios *termios = &tty->termios; 212 *termios = tty_std_termios; 213 termios->c_cflag = B9600 | CS8 214 | CREAD | HUPCL | CLOCAL; 215 termios->c_ispeed = 9600; 216 termios->c_ospeed = 9600; 217 } 218 219 static void ark3116_set_termios(struct tty_struct *tty, 220 struct usb_serial_port *port, 221 struct ktermios *old_termios) 222 { 223 struct usb_serial *serial = port->serial; 224 struct ark3116_private *priv = usb_get_serial_port_data(port); 225 struct ktermios *termios = &tty->termios; 226 unsigned int cflag = termios->c_cflag; 227 int bps = tty_get_baud_rate(tty); 228 int quot; 229 __u8 lcr, hcr, eval; 230 231 /* set data bit count */ 232 switch (cflag & CSIZE) { 233 case CS5: 234 lcr = UART_LCR_WLEN5; 235 break; 236 case CS6: 237 lcr = UART_LCR_WLEN6; 238 break; 239 case CS7: 240 lcr = UART_LCR_WLEN7; 241 break; 242 default: 243 case CS8: 244 lcr = UART_LCR_WLEN8; 245 break; 246 } 247 if (cflag & CSTOPB) 248 lcr |= UART_LCR_STOP; 249 if (cflag & PARENB) 250 lcr |= UART_LCR_PARITY; 251 if (!(cflag & PARODD)) 252 lcr |= UART_LCR_EPAR; 253 #ifdef CMSPAR 254 if (cflag & CMSPAR) 255 lcr |= UART_LCR_SPAR; 256 #endif 257 /* handshake control */ 258 hcr = (cflag & CRTSCTS) ? 0x03 : 0x00; 259 260 /* calc baudrate */ 261 dev_dbg(&port->dev, "%s - setting bps to %d\n", __func__, bps); 262 eval = 0; 263 switch (bps) { 264 case 0: 265 quot = calc_divisor(9600); 266 break; 267 default: 268 if ((bps < 75) || (bps > 3000000)) 269 bps = 9600; 270 quot = calc_divisor(bps); 271 break; 272 case 460800: 273 eval = 1; 274 quot = calc_divisor(bps); 275 break; 276 case 921600: 277 eval = 2; 278 quot = calc_divisor(bps); 279 break; 280 } 281 282 /* Update state: synchronize */ 283 mutex_lock(&priv->hw_lock); 284 285 /* keep old LCR_SBC bit */ 286 lcr |= (priv->lcr & UART_LCR_SBC); 287 288 dev_dbg(&port->dev, "%s - setting hcr:0x%02x,lcr:0x%02x,quot:%d\n", 289 __func__, hcr, lcr, quot); 290 291 /* handshake control */ 292 if (priv->hcr != hcr) { 293 priv->hcr = hcr; 294 ark3116_write_reg(serial, 0x8, hcr); 295 } 296 297 /* baudrate */ 298 if (priv->quot != quot) { 299 priv->quot = quot; 300 priv->lcr = lcr; /* need to write lcr anyway */ 301 302 /* disable DMA since transmit/receive is 303 * shadowed by UART_DLL 304 */ 305 ark3116_write_reg(serial, UART_FCR, 0); 306 307 ark3116_write_reg(serial, UART_LCR, 308 lcr|UART_LCR_DLAB); 309 ark3116_write_reg(serial, UART_DLL, quot & 0xff); 310 ark3116_write_reg(serial, UART_DLM, (quot>>8) & 0xff); 311 312 /* restore lcr */ 313 ark3116_write_reg(serial, UART_LCR, lcr); 314 /* magic baudrate thingy: not sure what it does, 315 * but windows does this as well. 316 */ 317 ark3116_write_reg(serial, 0xe, eval); 318 319 /* enable DMA */ 320 ark3116_write_reg(serial, UART_FCR, UART_FCR_DMA_SELECT); 321 } else if (priv->lcr != lcr) { 322 priv->lcr = lcr; 323 ark3116_write_reg(serial, UART_LCR, lcr); 324 } 325 326 mutex_unlock(&priv->hw_lock); 327 328 /* check for software flow control */ 329 if (I_IXOFF(tty) || I_IXON(tty)) { 330 dev_warn(&serial->dev->dev, 331 "%s: don't know how to do software flow control\n", 332 KBUILD_MODNAME); 333 } 334 335 /* Don't rewrite B0 */ 336 if (tty_termios_baud_rate(termios)) 337 tty_termios_encode_baud_rate(termios, bps, bps); 338 } 339 340 static void ark3116_close(struct usb_serial_port *port) 341 { 342 struct usb_serial *serial = port->serial; 343 344 if (serial->dev) { 345 /* disable DMA */ 346 ark3116_write_reg(serial, UART_FCR, 0); 347 348 /* deactivate interrupts */ 349 ark3116_write_reg(serial, UART_IER, 0); 350 351 usb_serial_generic_close(port); 352 if (serial->num_interrupt_in) 353 usb_kill_urb(port->interrupt_in_urb); 354 } 355 356 } 357 358 static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port) 359 { 360 struct ark3116_private *priv = usb_get_serial_port_data(port); 361 struct usb_serial *serial = port->serial; 362 unsigned char *buf; 363 int result; 364 365 buf = kmalloc(1, GFP_KERNEL); 366 if (buf == NULL) 367 return -ENOMEM; 368 369 result = usb_serial_generic_open(tty, port); 370 if (result) { 371 dev_dbg(&port->dev, 372 "%s - usb_serial_generic_open failed: %d\n", 373 __func__, result); 374 goto err_out; 375 } 376 377 /* remove any data still left: also clears error state */ 378 ark3116_read_reg(serial, UART_RX, buf); 379 380 /* read modem status */ 381 priv->msr = ark3116_read_reg(serial, UART_MSR, buf); 382 /* read line status */ 383 priv->lsr = ark3116_read_reg(serial, UART_LSR, buf); 384 385 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 386 if (result) { 387 dev_err(&port->dev, "submit irq_in urb failed %d\n", 388 result); 389 ark3116_close(port); 390 goto err_out; 391 } 392 393 /* activate interrupts */ 394 ark3116_write_reg(port->serial, UART_IER, UART_IER_MSI|UART_IER_RLSI); 395 396 /* enable DMA */ 397 ark3116_write_reg(port->serial, UART_FCR, UART_FCR_DMA_SELECT); 398 399 /* setup termios */ 400 if (tty) 401 ark3116_set_termios(tty, port, NULL); 402 403 err_out: 404 kfree(buf); 405 return result; 406 } 407 408 static int ark3116_get_icount(struct tty_struct *tty, 409 struct serial_icounter_struct *icount) 410 { 411 struct usb_serial_port *port = tty->driver_data; 412 struct ark3116_private *priv = usb_get_serial_port_data(port); 413 struct async_icount cnow = priv->icount; 414 icount->cts = cnow.cts; 415 icount->dsr = cnow.dsr; 416 icount->rng = cnow.rng; 417 icount->dcd = cnow.dcd; 418 icount->rx = cnow.rx; 419 icount->tx = cnow.tx; 420 icount->frame = cnow.frame; 421 icount->overrun = cnow.overrun; 422 icount->parity = cnow.parity; 423 icount->brk = cnow.brk; 424 icount->buf_overrun = cnow.buf_overrun; 425 return 0; 426 } 427 428 static int ark3116_ioctl(struct tty_struct *tty, 429 unsigned int cmd, unsigned long arg) 430 { 431 struct usb_serial_port *port = tty->driver_data; 432 struct ark3116_private *priv = usb_get_serial_port_data(port); 433 struct serial_struct serstruct; 434 void __user *user_arg = (void __user *)arg; 435 436 switch (cmd) { 437 case TIOCGSERIAL: 438 /* XXX: Some of these values are probably wrong. */ 439 memset(&serstruct, 0, sizeof(serstruct)); 440 serstruct.type = PORT_16654; 441 serstruct.line = port->serial->minor; 442 serstruct.port = port->number; 443 serstruct.custom_divisor = 0; 444 serstruct.baud_base = 460800; 445 446 if (copy_to_user(user_arg, &serstruct, sizeof(serstruct))) 447 return -EFAULT; 448 449 return 0; 450 case TIOCSSERIAL: 451 if (copy_from_user(&serstruct, user_arg, sizeof(serstruct))) 452 return -EFAULT; 453 return 0; 454 case TIOCMIWAIT: 455 for (;;) { 456 struct async_icount prev = priv->icount; 457 interruptible_sleep_on(&port->delta_msr_wait); 458 /* see if a signal did it */ 459 if (signal_pending(current)) 460 return -ERESTARTSYS; 461 462 if (port->serial->disconnected) 463 return -EIO; 464 465 if ((prev.rng == priv->icount.rng) && 466 (prev.dsr == priv->icount.dsr) && 467 (prev.dcd == priv->icount.dcd) && 468 (prev.cts == priv->icount.cts)) 469 return -EIO; 470 if ((arg & TIOCM_RNG && 471 (prev.rng != priv->icount.rng)) || 472 (arg & TIOCM_DSR && 473 (prev.dsr != priv->icount.dsr)) || 474 (arg & TIOCM_CD && 475 (prev.dcd != priv->icount.dcd)) || 476 (arg & TIOCM_CTS && 477 (prev.cts != priv->icount.cts))) 478 return 0; 479 } 480 break; 481 } 482 483 return -ENOIOCTLCMD; 484 } 485 486 static int ark3116_tiocmget(struct tty_struct *tty) 487 { 488 struct usb_serial_port *port = tty->driver_data; 489 struct ark3116_private *priv = usb_get_serial_port_data(port); 490 __u32 status; 491 __u32 ctrl; 492 unsigned long flags; 493 494 mutex_lock(&priv->hw_lock); 495 ctrl = priv->mcr; 496 mutex_unlock(&priv->hw_lock); 497 498 spin_lock_irqsave(&priv->status_lock, flags); 499 status = priv->msr; 500 spin_unlock_irqrestore(&priv->status_lock, flags); 501 502 return (status & UART_MSR_DSR ? TIOCM_DSR : 0) | 503 (status & UART_MSR_CTS ? TIOCM_CTS : 0) | 504 (status & UART_MSR_RI ? TIOCM_RI : 0) | 505 (status & UART_MSR_DCD ? TIOCM_CD : 0) | 506 (ctrl & UART_MCR_DTR ? TIOCM_DTR : 0) | 507 (ctrl & UART_MCR_RTS ? TIOCM_RTS : 0) | 508 (ctrl & UART_MCR_OUT1 ? TIOCM_OUT1 : 0) | 509 (ctrl & UART_MCR_OUT2 ? TIOCM_OUT2 : 0); 510 } 511 512 static int ark3116_tiocmset(struct tty_struct *tty, 513 unsigned set, unsigned clr) 514 { 515 struct usb_serial_port *port = tty->driver_data; 516 struct ark3116_private *priv = usb_get_serial_port_data(port); 517 518 /* we need to take the mutex here, to make sure that the value 519 * in priv->mcr is actually the one that is in the hardware 520 */ 521 522 mutex_lock(&priv->hw_lock); 523 524 if (set & TIOCM_RTS) 525 priv->mcr |= UART_MCR_RTS; 526 if (set & TIOCM_DTR) 527 priv->mcr |= UART_MCR_DTR; 528 if (set & TIOCM_OUT1) 529 priv->mcr |= UART_MCR_OUT1; 530 if (set & TIOCM_OUT2) 531 priv->mcr |= UART_MCR_OUT2; 532 if (clr & TIOCM_RTS) 533 priv->mcr &= ~UART_MCR_RTS; 534 if (clr & TIOCM_DTR) 535 priv->mcr &= ~UART_MCR_DTR; 536 if (clr & TIOCM_OUT1) 537 priv->mcr &= ~UART_MCR_OUT1; 538 if (clr & TIOCM_OUT2) 539 priv->mcr &= ~UART_MCR_OUT2; 540 541 ark3116_write_reg(port->serial, UART_MCR, priv->mcr); 542 543 mutex_unlock(&priv->hw_lock); 544 545 return 0; 546 } 547 548 static void ark3116_break_ctl(struct tty_struct *tty, int break_state) 549 { 550 struct usb_serial_port *port = tty->driver_data; 551 struct ark3116_private *priv = usb_get_serial_port_data(port); 552 553 /* LCR is also used for other things: protect access */ 554 mutex_lock(&priv->hw_lock); 555 556 if (break_state) 557 priv->lcr |= UART_LCR_SBC; 558 else 559 priv->lcr &= ~UART_LCR_SBC; 560 561 ark3116_write_reg(port->serial, UART_LCR, priv->lcr); 562 563 mutex_unlock(&priv->hw_lock); 564 } 565 566 static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr) 567 { 568 struct ark3116_private *priv = usb_get_serial_port_data(port); 569 unsigned long flags; 570 571 spin_lock_irqsave(&priv->status_lock, flags); 572 priv->msr = msr; 573 spin_unlock_irqrestore(&priv->status_lock, flags); 574 575 if (msr & UART_MSR_ANY_DELTA) { 576 /* update input line counters */ 577 if (msr & UART_MSR_DCTS) 578 priv->icount.cts++; 579 if (msr & UART_MSR_DDSR) 580 priv->icount.dsr++; 581 if (msr & UART_MSR_DDCD) 582 priv->icount.dcd++; 583 if (msr & UART_MSR_TERI) 584 priv->icount.rng++; 585 wake_up_interruptible(&port->delta_msr_wait); 586 } 587 } 588 589 static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr) 590 { 591 struct ark3116_private *priv = usb_get_serial_port_data(port); 592 unsigned long flags; 593 594 spin_lock_irqsave(&priv->status_lock, flags); 595 /* combine bits */ 596 priv->lsr |= lsr; 597 spin_unlock_irqrestore(&priv->status_lock, flags); 598 599 if (lsr&UART_LSR_BRK_ERROR_BITS) { 600 if (lsr & UART_LSR_BI) 601 priv->icount.brk++; 602 if (lsr & UART_LSR_FE) 603 priv->icount.frame++; 604 if (lsr & UART_LSR_PE) 605 priv->icount.parity++; 606 if (lsr & UART_LSR_OE) 607 priv->icount.overrun++; 608 } 609 } 610 611 static void ark3116_read_int_callback(struct urb *urb) 612 { 613 struct usb_serial_port *port = urb->context; 614 int status = urb->status; 615 const __u8 *data = urb->transfer_buffer; 616 int result; 617 618 switch (status) { 619 case -ECONNRESET: 620 case -ENOENT: 621 case -ESHUTDOWN: 622 /* this urb is terminated, clean up */ 623 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n", 624 __func__, status); 625 return; 626 default: 627 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n", 628 __func__, status); 629 break; 630 case 0: /* success */ 631 /* discovered this by trail and error... */ 632 if ((urb->actual_length == 4) && (data[0] == 0xe8)) { 633 const __u8 id = data[1]&UART_IIR_ID; 634 dev_dbg(&port->dev, "%s: iir=%02x\n", __func__, data[1]); 635 if (id == UART_IIR_MSI) { 636 dev_dbg(&port->dev, "%s: msr=%02x\n", 637 __func__, data[3]); 638 ark3116_update_msr(port, data[3]); 639 break; 640 } else if (id == UART_IIR_RLSI) { 641 dev_dbg(&port->dev, "%s: lsr=%02x\n", 642 __func__, data[2]); 643 ark3116_update_lsr(port, data[2]); 644 break; 645 } 646 } 647 /* 648 * Not sure what this data meant... 649 */ 650 usb_serial_debug_data(&port->dev, __func__, 651 urb->actual_length, 652 urb->transfer_buffer); 653 break; 654 } 655 656 result = usb_submit_urb(urb, GFP_ATOMIC); 657 if (result) 658 dev_err(&urb->dev->dev, 659 "%s - Error %d submitting interrupt urb\n", 660 __func__, result); 661 } 662 663 664 /* Data comes in via the bulk (data) URB, erors/interrupts via the int URB. 665 * This means that we cannot be sure which data byte has an associated error 666 * condition, so we report an error for all data in the next bulk read. 667 * 668 * Actually, there might even be a window between the bulk data leaving the 669 * ark and reading/resetting the lsr in the read_bulk_callback where an 670 * interrupt for the next data block could come in. 671 * Without somekind of ordering on the ark, we would have to report the 672 * error for the next block of data as well... 673 * For now, let's pretend this can't happen. 674 */ 675 static void ark3116_process_read_urb(struct urb *urb) 676 { 677 struct usb_serial_port *port = urb->context; 678 struct ark3116_private *priv = usb_get_serial_port_data(port); 679 unsigned char *data = urb->transfer_buffer; 680 char tty_flag = TTY_NORMAL; 681 unsigned long flags; 682 __u32 lsr; 683 684 /* update line status */ 685 spin_lock_irqsave(&priv->status_lock, flags); 686 lsr = priv->lsr; 687 priv->lsr &= ~UART_LSR_BRK_ERROR_BITS; 688 spin_unlock_irqrestore(&priv->status_lock, flags); 689 690 if (!urb->actual_length) 691 return; 692 693 if (lsr & UART_LSR_BRK_ERROR_BITS) { 694 if (lsr & UART_LSR_BI) 695 tty_flag = TTY_BREAK; 696 else if (lsr & UART_LSR_PE) 697 tty_flag = TTY_PARITY; 698 else if (lsr & UART_LSR_FE) 699 tty_flag = TTY_FRAME; 700 701 /* overrun is special, not associated with a char */ 702 if (lsr & UART_LSR_OE) 703 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN); 704 } 705 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag, 706 urb->actual_length); 707 tty_flip_buffer_push(&port->port); 708 } 709 710 static struct usb_serial_driver ark3116_device = { 711 .driver = { 712 .owner = THIS_MODULE, 713 .name = "ark3116", 714 }, 715 .id_table = id_table, 716 .num_ports = 1, 717 .attach = ark3116_attach, 718 .port_probe = ark3116_port_probe, 719 .port_remove = ark3116_port_remove, 720 .set_termios = ark3116_set_termios, 721 .init_termios = ark3116_init_termios, 722 .ioctl = ark3116_ioctl, 723 .tiocmget = ark3116_tiocmget, 724 .tiocmset = ark3116_tiocmset, 725 .get_icount = ark3116_get_icount, 726 .open = ark3116_open, 727 .close = ark3116_close, 728 .break_ctl = ark3116_break_ctl, 729 .read_int_callback = ark3116_read_int_callback, 730 .process_read_urb = ark3116_process_read_urb, 731 }; 732 733 static struct usb_serial_driver * const serial_drivers[] = { 734 &ark3116_device, NULL 735 }; 736 737 module_usb_serial_driver(serial_drivers, id_table); 738 739 MODULE_LICENSE("GPL"); 740 741 MODULE_AUTHOR(DRIVER_AUTHOR); 742 MODULE_DESCRIPTION(DRIVER_DESC); 743 744 /* 745 * The following describes what I learned from studying the old 746 * ark3116.c driver, disassembling the windows driver, and some lucky 747 * guesses. Since I do not have any datasheet or other 748 * documentation, inaccuracies are almost guaranteed. 749 * 750 * Some specs for the ARK3116 can be found here: 751 * http://web.archive.org/web/20060318000438/ 752 * www.arkmicro.com/en/products/view.php?id=10 753 * On that page, 2 GPIO pins are mentioned: I assume these are the 754 * OUT1 and OUT2 pins of the UART, so I added support for those 755 * through the MCR. Since the pins are not available on my hardware, 756 * I could not verify this. 757 * Also, it states there is "on-chip hardware flow control". I have 758 * discovered how to enable that. Unfortunately, I do not know how to 759 * enable XON/XOFF (software) flow control, which would need support 760 * from the chip as well to work. Because of the wording on the web 761 * page there is a real possibility the chip simply does not support 762 * software flow control. 763 * 764 * I got my ark3116 as part of a mobile phone adapter cable. On the 765 * PCB, the following numbered contacts are present: 766 * 767 * 1:- +5V 768 * 2:o DTR 769 * 3:i RX 770 * 4:i DCD 771 * 5:o RTS 772 * 6:o TX 773 * 7:i RI 774 * 8:i DSR 775 * 10:- 0V 776 * 11:i CTS 777 * 778 * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that 779 * may be different for the one you have ;-). 780 * 781 * The windows driver limits the registers to 0-F, so I assume there 782 * are actually 16 present on the device. 783 * 784 * On an UART interrupt, 4 bytes of data come in on the interrupt 785 * endpoint. The bytes are 0xe8 IIR LSR MSR. 786 * 787 * The baudrate seems to be generated from the 12MHz crystal, using 788 * 4-times subsampling. So quot=12e6/(4*baud). Also see description 789 * of register E. 790 * 791 * Registers 0-7: 792 * These seem to be the same as for a regular 16450. The FCR is set 793 * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between 794 * the UART and the USB bridge/DMA engine. 795 * 796 * Register 8: 797 * By trial and error, I found out that bit 0 enables hardware CTS, 798 * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making 799 * RTS +5V when the 3116 cannot transfer the data to the USB bus 800 * (verified by disabling the reading URB). Note that as far as I can 801 * tell, the windows driver does NOT use this, so there might be some 802 * hardware bug or something. 803 * 804 * According to a patch provided here 805 * (http://lkml.org/lkml/2009/7/26/56), the ARK3116 can also be used 806 * as an IrDA dongle. Since I do not have such a thing, I could not 807 * investigate that aspect. However, I can speculate ;-). 808 * 809 * - IrDA encodes data differently than RS232. Most likely, one of 810 * the bits in registers 9..E enables the IR ENDEC (encoder/decoder). 811 * - Depending on the IR transceiver, the input and output need to be 812 * inverted, so there are probably bits for that as well. 813 * - IrDA is half-duplex, so there should be a bit for selecting that. 814 * 815 * This still leaves at least two registers unaccounted for. Perhaps 816 * The chip can do XON/XOFF or CRC in HW? 817 * 818 * Register 9: 819 * Set to 0x00 for IrDA, when the baudrate is initialised. 820 * 821 * Register A: 822 * Set to 0x01 for IrDA, at init. 823 * 824 * Register B: 825 * Set to 0x01 for IrDA, 0x00 for RS232, at init. 826 * 827 * Register C: 828 * Set to 00 for IrDA, at init. 829 * 830 * Register D: 831 * Set to 0x41 for IrDA, at init. 832 * 833 * Register E: 834 * Somekind of baudrate override. The windows driver seems to set 835 * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600. 836 * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer, 837 * it could be somekind of subdivisor thingy. 838 * However,it does not seem to do anything: selecting 921600 (divisor 3, 839 * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would 840 * work, but they don't. 841 * 842 * Register F: unknown 843 */ 844