1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk> 4 * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de> 5 * Copyright 2009, Boris Hajduk <boris@hajduk.org> 6 * 7 * ch341.c implements a serial port driver for the Winchiphead CH341. 8 * 9 * The CH341 device can be used to implement an RS232 asynchronous 10 * serial port, an IEEE-1284 parallel printer port or a memory-like 11 * interface. In all cases the CH341 supports an I2C interface as well. 12 * This driver only supports the asynchronous serial interface. 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/tty.h> 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/usb.h> 20 #include <linux/usb/serial.h> 21 #include <linux/serial.h> 22 #include <asm/unaligned.h> 23 24 #define DEFAULT_BAUD_RATE 9600 25 #define DEFAULT_TIMEOUT 1000 26 27 /* flags for IO-Bits */ 28 #define CH341_BIT_RTS (1 << 6) 29 #define CH341_BIT_DTR (1 << 5) 30 31 /******************************/ 32 /* interrupt pipe definitions */ 33 /******************************/ 34 /* always 4 interrupt bytes */ 35 /* first irq byte normally 0x08 */ 36 /* second irq byte base 0x7d + below */ 37 /* third irq byte base 0x94 + below */ 38 /* fourth irq byte normally 0xee */ 39 40 /* second interrupt byte */ 41 #define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */ 42 43 /* status returned in third interrupt answer byte, inverted in data 44 from irq */ 45 #define CH341_BIT_CTS 0x01 46 #define CH341_BIT_DSR 0x02 47 #define CH341_BIT_RI 0x04 48 #define CH341_BIT_DCD 0x08 49 #define CH341_BITS_MODEM_STAT 0x0f /* all bits */ 50 51 /* Break support - the information used to implement this was gleaned from 52 * the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato. 53 */ 54 55 #define CH341_REQ_READ_VERSION 0x5F 56 #define CH341_REQ_WRITE_REG 0x9A 57 #define CH341_REQ_READ_REG 0x95 58 #define CH341_REQ_SERIAL_INIT 0xA1 59 #define CH341_REQ_MODEM_CTRL 0xA4 60 61 #define CH341_REG_BREAK 0x05 62 #define CH341_REG_LCR 0x18 63 #define CH341_NBREAK_BITS 0x01 64 65 #define CH341_LCR_ENABLE_RX 0x80 66 #define CH341_LCR_ENABLE_TX 0x40 67 #define CH341_LCR_MARK_SPACE 0x20 68 #define CH341_LCR_PAR_EVEN 0x10 69 #define CH341_LCR_ENABLE_PAR 0x08 70 #define CH341_LCR_STOP_BITS_2 0x04 71 #define CH341_LCR_CS8 0x03 72 #define CH341_LCR_CS7 0x02 73 #define CH341_LCR_CS6 0x01 74 #define CH341_LCR_CS5 0x00 75 76 #define CH341_QUIRK_LIMITED_PRESCALER BIT(0) 77 78 static const struct usb_device_id id_table[] = { 79 { USB_DEVICE(0x4348, 0x5523) }, 80 { USB_DEVICE(0x1a86, 0x7523) }, 81 { USB_DEVICE(0x1a86, 0x5523) }, 82 { }, 83 }; 84 MODULE_DEVICE_TABLE(usb, id_table); 85 86 struct ch341_private { 87 spinlock_t lock; /* access lock */ 88 unsigned baud_rate; /* set baud rate */ 89 u8 mcr; 90 u8 msr; 91 u8 lcr; 92 unsigned long quirks; 93 }; 94 95 static void ch341_set_termios(struct tty_struct *tty, 96 struct usb_serial_port *port, 97 struct ktermios *old_termios); 98 99 static int ch341_control_out(struct usb_device *dev, u8 request, 100 u16 value, u16 index) 101 { 102 int r; 103 104 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__, 105 request, value, index); 106 107 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, 108 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, 109 value, index, NULL, 0, DEFAULT_TIMEOUT); 110 if (r < 0) 111 dev_err(&dev->dev, "failed to send control message: %d\n", r); 112 113 return r; 114 } 115 116 static int ch341_control_in(struct usb_device *dev, 117 u8 request, u16 value, u16 index, 118 char *buf, unsigned bufsize) 119 { 120 int r; 121 122 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__, 123 request, value, index, bufsize); 124 125 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, 126 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, 127 value, index, buf, bufsize, DEFAULT_TIMEOUT); 128 if (r < (int)bufsize) { 129 if (r >= 0) { 130 dev_err(&dev->dev, 131 "short control message received (%d < %u)\n", 132 r, bufsize); 133 r = -EIO; 134 } 135 136 dev_err(&dev->dev, "failed to receive control message: %d\n", 137 r); 138 return r; 139 } 140 141 return 0; 142 } 143 144 #define CH341_CLKRATE 48000000 145 #define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact))) 146 #define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512)) 147 148 static const speed_t ch341_min_rates[] = { 149 CH341_MIN_RATE(0), 150 CH341_MIN_RATE(1), 151 CH341_MIN_RATE(2), 152 CH341_MIN_RATE(3), 153 }; 154 155 /* 156 * The device line speed is given by the following equation: 157 * 158 * baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where 159 * 160 * 0 <= ps <= 3, 161 * 0 <= fact <= 1, 162 * 2 <= div <= 256 if fact = 0, or 163 * 9 <= div <= 256 if fact = 1 164 */ 165 static int ch341_get_divisor(struct ch341_private *priv) 166 { 167 unsigned int fact, div, clk_div; 168 speed_t speed = priv->baud_rate; 169 bool force_fact0 = false; 170 int ps; 171 172 /* 173 * Clamp to supported range, this makes the (ps < 0) and (div < 2) 174 * sanity checks below redundant. 175 */ 176 speed = clamp(speed, 46U, 3000000U); 177 178 /* 179 * Start with highest possible base clock (fact = 1) that will give a 180 * divisor strictly less than 512. 181 */ 182 fact = 1; 183 for (ps = 3; ps >= 0; ps--) { 184 if (speed > ch341_min_rates[ps]) 185 break; 186 } 187 188 if (ps < 0) 189 return -EINVAL; 190 191 /* Determine corresponding divisor, rounding down. */ 192 clk_div = CH341_CLK_DIV(ps, fact); 193 div = CH341_CLKRATE / (clk_div * speed); 194 195 /* Some devices require a lower base clock if ps < 3. */ 196 if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER)) 197 force_fact0 = true; 198 199 /* Halve base clock (fact = 0) if required. */ 200 if (div < 9 || div > 255 || force_fact0) { 201 div /= 2; 202 clk_div *= 2; 203 fact = 0; 204 } 205 206 if (div < 2) 207 return -EINVAL; 208 209 /* 210 * Pick next divisor if resulting rate is closer to the requested one, 211 * scale up to avoid rounding errors on low rates. 212 */ 213 if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >= 214 16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1))) 215 div++; 216 217 /* 218 * Prefer lower base clock (fact = 0) if even divisor. 219 * 220 * Note that this makes the receiver more tolerant to errors. 221 */ 222 if (fact == 1 && div % 2 == 0) { 223 div /= 2; 224 fact = 0; 225 } 226 227 return (0x100 - div) << 8 | fact << 2 | ps; 228 } 229 230 static int ch341_set_baudrate_lcr(struct usb_device *dev, 231 struct ch341_private *priv, u8 lcr) 232 { 233 int val; 234 int r; 235 236 if (!priv->baud_rate) 237 return -EINVAL; 238 239 val = ch341_get_divisor(priv); 240 if (val < 0) 241 return -EINVAL; 242 243 /* 244 * CH341A buffers data until a full endpoint-size packet (32 bytes) 245 * has been received unless bit 7 is set. 246 */ 247 val |= BIT(7); 248 249 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, val); 250 if (r) 251 return r; 252 253 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr); 254 if (r) 255 return r; 256 257 return r; 258 } 259 260 static int ch341_set_handshake(struct usb_device *dev, u8 control) 261 { 262 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0); 263 } 264 265 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv) 266 { 267 const unsigned int size = 2; 268 char *buffer; 269 int r; 270 unsigned long flags; 271 272 buffer = kmalloc(size, GFP_KERNEL); 273 if (!buffer) 274 return -ENOMEM; 275 276 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size); 277 if (r < 0) 278 goto out; 279 280 spin_lock_irqsave(&priv->lock, flags); 281 priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT; 282 spin_unlock_irqrestore(&priv->lock, flags); 283 284 out: kfree(buffer); 285 return r; 286 } 287 288 /* -------------------------------------------------------------------------- */ 289 290 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) 291 { 292 const unsigned int size = 2; 293 char *buffer; 294 int r; 295 296 buffer = kmalloc(size, GFP_KERNEL); 297 if (!buffer) 298 return -ENOMEM; 299 300 /* expect two bytes 0x27 0x00 */ 301 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size); 302 if (r < 0) 303 goto out; 304 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]); 305 306 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0); 307 if (r < 0) 308 goto out; 309 310 r = ch341_set_baudrate_lcr(dev, priv, priv->lcr); 311 if (r < 0) 312 goto out; 313 314 r = ch341_set_handshake(dev, priv->mcr); 315 316 out: kfree(buffer); 317 return r; 318 } 319 320 static int ch341_detect_quirks(struct usb_serial_port *port) 321 { 322 struct ch341_private *priv = usb_get_serial_port_data(port); 323 struct usb_device *udev = port->serial->dev; 324 const unsigned int size = 2; 325 unsigned long quirks = 0; 326 char *buffer; 327 int r; 328 329 buffer = kmalloc(size, GFP_KERNEL); 330 if (!buffer) 331 return -ENOMEM; 332 333 /* 334 * A subset of CH34x devices does not support all features. The 335 * prescaler is limited and there is no support for sending a RS232 336 * break condition. A read failure when trying to set up the latter is 337 * used to detect these devices. 338 */ 339 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, 340 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, 341 CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); 342 if (r == -EPIPE) { 343 dev_dbg(&port->dev, "break control not supported\n"); 344 quirks = CH341_QUIRK_LIMITED_PRESCALER; 345 r = 0; 346 goto out; 347 } 348 349 if (r != size) { 350 if (r >= 0) 351 r = -EIO; 352 dev_err(&port->dev, "failed to read break control: %d\n", r); 353 goto out; 354 } 355 356 r = 0; 357 out: 358 kfree(buffer); 359 360 if (quirks) { 361 dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); 362 priv->quirks |= quirks; 363 } 364 365 return r; 366 } 367 368 static int ch341_port_probe(struct usb_serial_port *port) 369 { 370 struct ch341_private *priv; 371 int r; 372 373 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL); 374 if (!priv) 375 return -ENOMEM; 376 377 spin_lock_init(&priv->lock); 378 priv->baud_rate = DEFAULT_BAUD_RATE; 379 /* 380 * Some CH340 devices appear unable to change the initial LCR 381 * settings, so set a sane 8N1 default. 382 */ 383 priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8; 384 385 r = ch341_configure(port->serial->dev, priv); 386 if (r < 0) 387 goto error; 388 389 usb_set_serial_port_data(port, priv); 390 391 r = ch341_detect_quirks(port); 392 if (r < 0) 393 goto error; 394 395 return 0; 396 397 error: kfree(priv); 398 return r; 399 } 400 401 static int ch341_port_remove(struct usb_serial_port *port) 402 { 403 struct ch341_private *priv; 404 405 priv = usb_get_serial_port_data(port); 406 kfree(priv); 407 408 return 0; 409 } 410 411 static int ch341_carrier_raised(struct usb_serial_port *port) 412 { 413 struct ch341_private *priv = usb_get_serial_port_data(port); 414 if (priv->msr & CH341_BIT_DCD) 415 return 1; 416 return 0; 417 } 418 419 static void ch341_dtr_rts(struct usb_serial_port *port, int on) 420 { 421 struct ch341_private *priv = usb_get_serial_port_data(port); 422 unsigned long flags; 423 424 /* drop DTR and RTS */ 425 spin_lock_irqsave(&priv->lock, flags); 426 if (on) 427 priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR; 428 else 429 priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR); 430 spin_unlock_irqrestore(&priv->lock, flags); 431 ch341_set_handshake(port->serial->dev, priv->mcr); 432 } 433 434 static void ch341_close(struct usb_serial_port *port) 435 { 436 usb_serial_generic_close(port); 437 usb_kill_urb(port->interrupt_in_urb); 438 } 439 440 441 /* open this device, set default parameters */ 442 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port) 443 { 444 struct ch341_private *priv = usb_get_serial_port_data(port); 445 int r; 446 447 if (tty) 448 ch341_set_termios(tty, port, NULL); 449 450 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__); 451 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 452 if (r) { 453 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n", 454 __func__, r); 455 return r; 456 } 457 458 r = ch341_get_status(port->serial->dev, priv); 459 if (r < 0) { 460 dev_err(&port->dev, "failed to read modem status: %d\n", r); 461 goto err_kill_interrupt_urb; 462 } 463 464 r = usb_serial_generic_open(tty, port); 465 if (r) 466 goto err_kill_interrupt_urb; 467 468 return 0; 469 470 err_kill_interrupt_urb: 471 usb_kill_urb(port->interrupt_in_urb); 472 473 return r; 474 } 475 476 /* Old_termios contains the original termios settings and 477 * tty->termios contains the new setting to be used. 478 */ 479 static void ch341_set_termios(struct tty_struct *tty, 480 struct usb_serial_port *port, struct ktermios *old_termios) 481 { 482 struct ch341_private *priv = usb_get_serial_port_data(port); 483 unsigned baud_rate; 484 unsigned long flags; 485 u8 lcr; 486 int r; 487 488 /* redundant changes may cause the chip to lose bytes */ 489 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios)) 490 return; 491 492 baud_rate = tty_get_baud_rate(tty); 493 494 lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX; 495 496 switch (C_CSIZE(tty)) { 497 case CS5: 498 lcr |= CH341_LCR_CS5; 499 break; 500 case CS6: 501 lcr |= CH341_LCR_CS6; 502 break; 503 case CS7: 504 lcr |= CH341_LCR_CS7; 505 break; 506 case CS8: 507 lcr |= CH341_LCR_CS8; 508 break; 509 } 510 511 if (C_PARENB(tty)) { 512 lcr |= CH341_LCR_ENABLE_PAR; 513 if (C_PARODD(tty) == 0) 514 lcr |= CH341_LCR_PAR_EVEN; 515 if (C_CMSPAR(tty)) 516 lcr |= CH341_LCR_MARK_SPACE; 517 } 518 519 if (C_CSTOPB(tty)) 520 lcr |= CH341_LCR_STOP_BITS_2; 521 522 if (baud_rate) { 523 priv->baud_rate = baud_rate; 524 525 r = ch341_set_baudrate_lcr(port->serial->dev, priv, lcr); 526 if (r < 0 && old_termios) { 527 priv->baud_rate = tty_termios_baud_rate(old_termios); 528 tty_termios_copy_hw(&tty->termios, old_termios); 529 } else if (r == 0) { 530 priv->lcr = lcr; 531 } 532 } 533 534 spin_lock_irqsave(&priv->lock, flags); 535 if (C_BAUD(tty) == B0) 536 priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS); 537 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0) 538 priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS); 539 spin_unlock_irqrestore(&priv->lock, flags); 540 541 ch341_set_handshake(port->serial->dev, priv->mcr); 542 } 543 544 static void ch341_break_ctl(struct tty_struct *tty, int break_state) 545 { 546 const uint16_t ch341_break_reg = 547 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK; 548 struct usb_serial_port *port = tty->driver_data; 549 int r; 550 uint16_t reg_contents; 551 uint8_t *break_reg; 552 553 break_reg = kmalloc(2, GFP_KERNEL); 554 if (!break_reg) 555 return; 556 557 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG, 558 ch341_break_reg, 0, break_reg, 2); 559 if (r < 0) { 560 dev_err(&port->dev, "%s - USB control read error (%d)\n", 561 __func__, r); 562 goto out; 563 } 564 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n", 565 __func__, break_reg[0], break_reg[1]); 566 if (break_state != 0) { 567 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__); 568 break_reg[0] &= ~CH341_NBREAK_BITS; 569 break_reg[1] &= ~CH341_LCR_ENABLE_TX; 570 } else { 571 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__); 572 break_reg[0] |= CH341_NBREAK_BITS; 573 break_reg[1] |= CH341_LCR_ENABLE_TX; 574 } 575 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n", 576 __func__, break_reg[0], break_reg[1]); 577 reg_contents = get_unaligned_le16(break_reg); 578 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG, 579 ch341_break_reg, reg_contents); 580 if (r < 0) 581 dev_err(&port->dev, "%s - USB control write error (%d)\n", 582 __func__, r); 583 out: 584 kfree(break_reg); 585 } 586 587 static int ch341_tiocmset(struct tty_struct *tty, 588 unsigned int set, unsigned int clear) 589 { 590 struct usb_serial_port *port = tty->driver_data; 591 struct ch341_private *priv = usb_get_serial_port_data(port); 592 unsigned long flags; 593 u8 control; 594 595 spin_lock_irqsave(&priv->lock, flags); 596 if (set & TIOCM_RTS) 597 priv->mcr |= CH341_BIT_RTS; 598 if (set & TIOCM_DTR) 599 priv->mcr |= CH341_BIT_DTR; 600 if (clear & TIOCM_RTS) 601 priv->mcr &= ~CH341_BIT_RTS; 602 if (clear & TIOCM_DTR) 603 priv->mcr &= ~CH341_BIT_DTR; 604 control = priv->mcr; 605 spin_unlock_irqrestore(&priv->lock, flags); 606 607 return ch341_set_handshake(port->serial->dev, control); 608 } 609 610 static void ch341_update_status(struct usb_serial_port *port, 611 unsigned char *data, size_t len) 612 { 613 struct ch341_private *priv = usb_get_serial_port_data(port); 614 struct tty_struct *tty; 615 unsigned long flags; 616 u8 status; 617 u8 delta; 618 619 if (len < 4) 620 return; 621 622 status = ~data[2] & CH341_BITS_MODEM_STAT; 623 624 spin_lock_irqsave(&priv->lock, flags); 625 delta = status ^ priv->msr; 626 priv->msr = status; 627 spin_unlock_irqrestore(&priv->lock, flags); 628 629 if (data[1] & CH341_MULT_STAT) 630 dev_dbg(&port->dev, "%s - multiple status change\n", __func__); 631 632 if (!delta) 633 return; 634 635 if (delta & CH341_BIT_CTS) 636 port->icount.cts++; 637 if (delta & CH341_BIT_DSR) 638 port->icount.dsr++; 639 if (delta & CH341_BIT_RI) 640 port->icount.rng++; 641 if (delta & CH341_BIT_DCD) { 642 port->icount.dcd++; 643 tty = tty_port_tty_get(&port->port); 644 if (tty) { 645 usb_serial_handle_dcd_change(port, tty, 646 status & CH341_BIT_DCD); 647 tty_kref_put(tty); 648 } 649 } 650 651 wake_up_interruptible(&port->port.delta_msr_wait); 652 } 653 654 static void ch341_read_int_callback(struct urb *urb) 655 { 656 struct usb_serial_port *port = urb->context; 657 unsigned char *data = urb->transfer_buffer; 658 unsigned int len = urb->actual_length; 659 int status; 660 661 switch (urb->status) { 662 case 0: 663 /* success */ 664 break; 665 case -ECONNRESET: 666 case -ENOENT: 667 case -ESHUTDOWN: 668 /* this urb is terminated, clean up */ 669 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n", 670 __func__, urb->status); 671 return; 672 default: 673 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n", 674 __func__, urb->status); 675 goto exit; 676 } 677 678 usb_serial_debug_data(&port->dev, __func__, len, data); 679 ch341_update_status(port, data, len); 680 exit: 681 status = usb_submit_urb(urb, GFP_ATOMIC); 682 if (status) { 683 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n", 684 __func__, status); 685 } 686 } 687 688 static int ch341_tiocmget(struct tty_struct *tty) 689 { 690 struct usb_serial_port *port = tty->driver_data; 691 struct ch341_private *priv = usb_get_serial_port_data(port); 692 unsigned long flags; 693 u8 mcr; 694 u8 status; 695 unsigned int result; 696 697 spin_lock_irqsave(&priv->lock, flags); 698 mcr = priv->mcr; 699 status = priv->msr; 700 spin_unlock_irqrestore(&priv->lock, flags); 701 702 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0) 703 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0) 704 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0) 705 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0) 706 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0) 707 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0); 708 709 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result); 710 711 return result; 712 } 713 714 static int ch341_reset_resume(struct usb_serial *serial) 715 { 716 struct usb_serial_port *port = serial->port[0]; 717 struct ch341_private *priv; 718 int ret; 719 720 priv = usb_get_serial_port_data(port); 721 if (!priv) 722 return 0; 723 724 /* reconfigure ch341 serial port after bus-reset */ 725 ch341_configure(serial->dev, priv); 726 727 if (tty_port_initialized(&port->port)) { 728 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO); 729 if (ret) { 730 dev_err(&port->dev, "failed to submit interrupt urb: %d\n", 731 ret); 732 return ret; 733 } 734 735 ret = ch341_get_status(port->serial->dev, priv); 736 if (ret < 0) { 737 dev_err(&port->dev, "failed to read modem status: %d\n", 738 ret); 739 } 740 } 741 742 return usb_serial_generic_resume(serial); 743 } 744 745 static struct usb_serial_driver ch341_device = { 746 .driver = { 747 .owner = THIS_MODULE, 748 .name = "ch341-uart", 749 }, 750 .id_table = id_table, 751 .num_ports = 1, 752 .open = ch341_open, 753 .dtr_rts = ch341_dtr_rts, 754 .carrier_raised = ch341_carrier_raised, 755 .close = ch341_close, 756 .set_termios = ch341_set_termios, 757 .break_ctl = ch341_break_ctl, 758 .tiocmget = ch341_tiocmget, 759 .tiocmset = ch341_tiocmset, 760 .tiocmiwait = usb_serial_generic_tiocmiwait, 761 .read_int_callback = ch341_read_int_callback, 762 .port_probe = ch341_port_probe, 763 .port_remove = ch341_port_remove, 764 .reset_resume = ch341_reset_resume, 765 }; 766 767 static struct usb_serial_driver * const serial_drivers[] = { 768 &ch341_device, NULL 769 }; 770 771 module_usb_serial_driver(serial_drivers, id_table); 772 773 MODULE_LICENSE("GPL v2"); 774