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, 0x7522) }, 81 { USB_DEVICE(0x1a86, 0x7523) }, 82 { USB_DEVICE(0x1a86, 0x5523) }, 83 { }, 84 }; 85 MODULE_DEVICE_TABLE(usb, id_table); 86 87 struct ch341_private { 88 spinlock_t lock; /* access lock */ 89 unsigned baud_rate; /* set baud rate */ 90 u8 mcr; 91 u8 msr; 92 u8 lcr; 93 unsigned long quirks; 94 }; 95 96 static void ch341_set_termios(struct tty_struct *tty, 97 struct usb_serial_port *port, 98 struct ktermios *old_termios); 99 100 static int ch341_control_out(struct usb_device *dev, u8 request, 101 u16 value, u16 index) 102 { 103 int r; 104 105 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__, 106 request, value, index); 107 108 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, 109 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, 110 value, index, NULL, 0, DEFAULT_TIMEOUT); 111 if (r < 0) 112 dev_err(&dev->dev, "failed to send control message: %d\n", r); 113 114 return r; 115 } 116 117 static int ch341_control_in(struct usb_device *dev, 118 u8 request, u16 value, u16 index, 119 char *buf, unsigned bufsize) 120 { 121 int r; 122 123 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__, 124 request, value, index, bufsize); 125 126 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, 127 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, 128 value, index, buf, bufsize, DEFAULT_TIMEOUT); 129 if (r < (int)bufsize) { 130 if (r >= 0) { 131 dev_err(&dev->dev, 132 "short control message received (%d < %u)\n", 133 r, bufsize); 134 r = -EIO; 135 } 136 137 dev_err(&dev->dev, "failed to receive control message: %d\n", 138 r); 139 return r; 140 } 141 142 return 0; 143 } 144 145 #define CH341_CLKRATE 48000000 146 #define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact))) 147 #define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512)) 148 149 static const speed_t ch341_min_rates[] = { 150 CH341_MIN_RATE(0), 151 CH341_MIN_RATE(1), 152 CH341_MIN_RATE(2), 153 CH341_MIN_RATE(3), 154 }; 155 156 /* 157 * The device line speed is given by the following equation: 158 * 159 * baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where 160 * 161 * 0 <= ps <= 3, 162 * 0 <= fact <= 1, 163 * 2 <= div <= 256 if fact = 0, or 164 * 9 <= div <= 256 if fact = 1 165 */ 166 static int ch341_get_divisor(struct ch341_private *priv) 167 { 168 unsigned int fact, div, clk_div; 169 speed_t speed = priv->baud_rate; 170 bool force_fact0 = false; 171 int ps; 172 173 /* 174 * Clamp to supported range, this makes the (ps < 0) and (div < 2) 175 * sanity checks below redundant. 176 */ 177 speed = clamp(speed, 46U, 3000000U); 178 179 /* 180 * Start with highest possible base clock (fact = 1) that will give a 181 * divisor strictly less than 512. 182 */ 183 fact = 1; 184 for (ps = 3; ps >= 0; ps--) { 185 if (speed > ch341_min_rates[ps]) 186 break; 187 } 188 189 if (ps < 0) 190 return -EINVAL; 191 192 /* Determine corresponding divisor, rounding down. */ 193 clk_div = CH341_CLK_DIV(ps, fact); 194 div = CH341_CLKRATE / (clk_div * speed); 195 196 /* Some devices require a lower base clock if ps < 3. */ 197 if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER)) 198 force_fact0 = true; 199 200 /* Halve base clock (fact = 0) if required. */ 201 if (div < 9 || div > 255 || force_fact0) { 202 div /= 2; 203 clk_div *= 2; 204 fact = 0; 205 } 206 207 if (div < 2) 208 return -EINVAL; 209 210 /* 211 * Pick next divisor if resulting rate is closer to the requested one, 212 * scale up to avoid rounding errors on low rates. 213 */ 214 if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >= 215 16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1))) 216 div++; 217 218 /* 219 * Prefer lower base clock (fact = 0) if even divisor. 220 * 221 * Note that this makes the receiver more tolerant to errors. 222 */ 223 if (fact == 1 && div % 2 == 0) { 224 div /= 2; 225 fact = 0; 226 } 227 228 return (0x100 - div) << 8 | fact << 2 | ps; 229 } 230 231 static int ch341_set_baudrate_lcr(struct usb_device *dev, 232 struct ch341_private *priv, u8 lcr) 233 { 234 int val; 235 int r; 236 237 if (!priv->baud_rate) 238 return -EINVAL; 239 240 val = ch341_get_divisor(priv); 241 if (val < 0) 242 return -EINVAL; 243 244 /* 245 * CH341A buffers data until a full endpoint-size packet (32 bytes) 246 * has been received unless bit 7 is set. 247 */ 248 val |= BIT(7); 249 250 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, val); 251 if (r) 252 return r; 253 254 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr); 255 if (r) 256 return r; 257 258 return r; 259 } 260 261 static int ch341_set_handshake(struct usb_device *dev, u8 control) 262 { 263 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0); 264 } 265 266 static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv) 267 { 268 const unsigned int size = 2; 269 char *buffer; 270 int r; 271 unsigned long flags; 272 273 buffer = kmalloc(size, GFP_KERNEL); 274 if (!buffer) 275 return -ENOMEM; 276 277 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size); 278 if (r < 0) 279 goto out; 280 281 spin_lock_irqsave(&priv->lock, flags); 282 priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT; 283 spin_unlock_irqrestore(&priv->lock, flags); 284 285 out: kfree(buffer); 286 return r; 287 } 288 289 /* -------------------------------------------------------------------------- */ 290 291 static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) 292 { 293 const unsigned int size = 2; 294 char *buffer; 295 int r; 296 297 buffer = kmalloc(size, GFP_KERNEL); 298 if (!buffer) 299 return -ENOMEM; 300 301 /* expect two bytes 0x27 0x00 */ 302 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size); 303 if (r < 0) 304 goto out; 305 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]); 306 307 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0); 308 if (r < 0) 309 goto out; 310 311 r = ch341_set_baudrate_lcr(dev, priv, priv->lcr); 312 if (r < 0) 313 goto out; 314 315 r = ch341_set_handshake(dev, priv->mcr); 316 317 out: kfree(buffer); 318 return r; 319 } 320 321 static int ch341_detect_quirks(struct usb_serial_port *port) 322 { 323 struct ch341_private *priv = usb_get_serial_port_data(port); 324 struct usb_device *udev = port->serial->dev; 325 const unsigned int size = 2; 326 unsigned long quirks = 0; 327 char *buffer; 328 int r; 329 330 buffer = kmalloc(size, GFP_KERNEL); 331 if (!buffer) 332 return -ENOMEM; 333 334 /* 335 * A subset of CH34x devices does not support all features. The 336 * prescaler is limited and there is no support for sending a RS232 337 * break condition. A read failure when trying to set up the latter is 338 * used to detect these devices. 339 */ 340 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, 341 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, 342 CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); 343 if (r == -EPIPE) { 344 dev_dbg(&port->dev, "break control not supported\n"); 345 quirks = CH341_QUIRK_LIMITED_PRESCALER; 346 r = 0; 347 goto out; 348 } 349 350 if (r != size) { 351 if (r >= 0) 352 r = -EIO; 353 dev_err(&port->dev, "failed to read break control: %d\n", r); 354 goto out; 355 } 356 357 r = 0; 358 out: 359 kfree(buffer); 360 361 if (quirks) { 362 dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); 363 priv->quirks |= quirks; 364 } 365 366 return r; 367 } 368 369 static int ch341_port_probe(struct usb_serial_port *port) 370 { 371 struct ch341_private *priv; 372 int r; 373 374 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL); 375 if (!priv) 376 return -ENOMEM; 377 378 spin_lock_init(&priv->lock); 379 priv->baud_rate = DEFAULT_BAUD_RATE; 380 /* 381 * Some CH340 devices appear unable to change the initial LCR 382 * settings, so set a sane 8N1 default. 383 */ 384 priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8; 385 386 r = ch341_configure(port->serial->dev, priv); 387 if (r < 0) 388 goto error; 389 390 usb_set_serial_port_data(port, priv); 391 392 r = ch341_detect_quirks(port); 393 if (r < 0) 394 goto error; 395 396 return 0; 397 398 error: kfree(priv); 399 return r; 400 } 401 402 static int ch341_port_remove(struct usb_serial_port *port) 403 { 404 struct ch341_private *priv; 405 406 priv = usb_get_serial_port_data(port); 407 kfree(priv); 408 409 return 0; 410 } 411 412 static int ch341_carrier_raised(struct usb_serial_port *port) 413 { 414 struct ch341_private *priv = usb_get_serial_port_data(port); 415 if (priv->msr & CH341_BIT_DCD) 416 return 1; 417 return 0; 418 } 419 420 static void ch341_dtr_rts(struct usb_serial_port *port, int on) 421 { 422 struct ch341_private *priv = usb_get_serial_port_data(port); 423 unsigned long flags; 424 425 /* drop DTR and RTS */ 426 spin_lock_irqsave(&priv->lock, flags); 427 if (on) 428 priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR; 429 else 430 priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR); 431 spin_unlock_irqrestore(&priv->lock, flags); 432 ch341_set_handshake(port->serial->dev, priv->mcr); 433 } 434 435 static void ch341_close(struct usb_serial_port *port) 436 { 437 usb_serial_generic_close(port); 438 usb_kill_urb(port->interrupt_in_urb); 439 } 440 441 442 /* open this device, set default parameters */ 443 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port) 444 { 445 struct ch341_private *priv = usb_get_serial_port_data(port); 446 int r; 447 448 if (tty) 449 ch341_set_termios(tty, port, NULL); 450 451 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__); 452 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); 453 if (r) { 454 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n", 455 __func__, r); 456 return r; 457 } 458 459 r = ch341_get_status(port->serial->dev, priv); 460 if (r < 0) { 461 dev_err(&port->dev, "failed to read modem status: %d\n", r); 462 goto err_kill_interrupt_urb; 463 } 464 465 r = usb_serial_generic_open(tty, port); 466 if (r) 467 goto err_kill_interrupt_urb; 468 469 return 0; 470 471 err_kill_interrupt_urb: 472 usb_kill_urb(port->interrupt_in_urb); 473 474 return r; 475 } 476 477 /* Old_termios contains the original termios settings and 478 * tty->termios contains the new setting to be used. 479 */ 480 static void ch341_set_termios(struct tty_struct *tty, 481 struct usb_serial_port *port, struct ktermios *old_termios) 482 { 483 struct ch341_private *priv = usb_get_serial_port_data(port); 484 unsigned baud_rate; 485 unsigned long flags; 486 u8 lcr; 487 int r; 488 489 /* redundant changes may cause the chip to lose bytes */ 490 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios)) 491 return; 492 493 baud_rate = tty_get_baud_rate(tty); 494 495 lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX; 496 497 switch (C_CSIZE(tty)) { 498 case CS5: 499 lcr |= CH341_LCR_CS5; 500 break; 501 case CS6: 502 lcr |= CH341_LCR_CS6; 503 break; 504 case CS7: 505 lcr |= CH341_LCR_CS7; 506 break; 507 case CS8: 508 lcr |= CH341_LCR_CS8; 509 break; 510 } 511 512 if (C_PARENB(tty)) { 513 lcr |= CH341_LCR_ENABLE_PAR; 514 if (C_PARODD(tty) == 0) 515 lcr |= CH341_LCR_PAR_EVEN; 516 if (C_CMSPAR(tty)) 517 lcr |= CH341_LCR_MARK_SPACE; 518 } 519 520 if (C_CSTOPB(tty)) 521 lcr |= CH341_LCR_STOP_BITS_2; 522 523 if (baud_rate) { 524 priv->baud_rate = baud_rate; 525 526 r = ch341_set_baudrate_lcr(port->serial->dev, priv, lcr); 527 if (r < 0 && old_termios) { 528 priv->baud_rate = tty_termios_baud_rate(old_termios); 529 tty_termios_copy_hw(&tty->termios, old_termios); 530 } else if (r == 0) { 531 priv->lcr = lcr; 532 } 533 } 534 535 spin_lock_irqsave(&priv->lock, flags); 536 if (C_BAUD(tty) == B0) 537 priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS); 538 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0) 539 priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS); 540 spin_unlock_irqrestore(&priv->lock, flags); 541 542 ch341_set_handshake(port->serial->dev, priv->mcr); 543 } 544 545 static void ch341_break_ctl(struct tty_struct *tty, int break_state) 546 { 547 const uint16_t ch341_break_reg = 548 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK; 549 struct usb_serial_port *port = tty->driver_data; 550 int r; 551 uint16_t reg_contents; 552 uint8_t *break_reg; 553 554 break_reg = kmalloc(2, GFP_KERNEL); 555 if (!break_reg) 556 return; 557 558 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG, 559 ch341_break_reg, 0, break_reg, 2); 560 if (r < 0) { 561 dev_err(&port->dev, "%s - USB control read error (%d)\n", 562 __func__, r); 563 goto out; 564 } 565 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n", 566 __func__, break_reg[0], break_reg[1]); 567 if (break_state != 0) { 568 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__); 569 break_reg[0] &= ~CH341_NBREAK_BITS; 570 break_reg[1] &= ~CH341_LCR_ENABLE_TX; 571 } else { 572 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__); 573 break_reg[0] |= CH341_NBREAK_BITS; 574 break_reg[1] |= CH341_LCR_ENABLE_TX; 575 } 576 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n", 577 __func__, break_reg[0], break_reg[1]); 578 reg_contents = get_unaligned_le16(break_reg); 579 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG, 580 ch341_break_reg, reg_contents); 581 if (r < 0) 582 dev_err(&port->dev, "%s - USB control write error (%d)\n", 583 __func__, r); 584 out: 585 kfree(break_reg); 586 } 587 588 static int ch341_tiocmset(struct tty_struct *tty, 589 unsigned int set, unsigned int clear) 590 { 591 struct usb_serial_port *port = tty->driver_data; 592 struct ch341_private *priv = usb_get_serial_port_data(port); 593 unsigned long flags; 594 u8 control; 595 596 spin_lock_irqsave(&priv->lock, flags); 597 if (set & TIOCM_RTS) 598 priv->mcr |= CH341_BIT_RTS; 599 if (set & TIOCM_DTR) 600 priv->mcr |= CH341_BIT_DTR; 601 if (clear & TIOCM_RTS) 602 priv->mcr &= ~CH341_BIT_RTS; 603 if (clear & TIOCM_DTR) 604 priv->mcr &= ~CH341_BIT_DTR; 605 control = priv->mcr; 606 spin_unlock_irqrestore(&priv->lock, flags); 607 608 return ch341_set_handshake(port->serial->dev, control); 609 } 610 611 static void ch341_update_status(struct usb_serial_port *port, 612 unsigned char *data, size_t len) 613 { 614 struct ch341_private *priv = usb_get_serial_port_data(port); 615 struct tty_struct *tty; 616 unsigned long flags; 617 u8 status; 618 u8 delta; 619 620 if (len < 4) 621 return; 622 623 status = ~data[2] & CH341_BITS_MODEM_STAT; 624 625 spin_lock_irqsave(&priv->lock, flags); 626 delta = status ^ priv->msr; 627 priv->msr = status; 628 spin_unlock_irqrestore(&priv->lock, flags); 629 630 if (data[1] & CH341_MULT_STAT) 631 dev_dbg(&port->dev, "%s - multiple status change\n", __func__); 632 633 if (!delta) 634 return; 635 636 if (delta & CH341_BIT_CTS) 637 port->icount.cts++; 638 if (delta & CH341_BIT_DSR) 639 port->icount.dsr++; 640 if (delta & CH341_BIT_RI) 641 port->icount.rng++; 642 if (delta & CH341_BIT_DCD) { 643 port->icount.dcd++; 644 tty = tty_port_tty_get(&port->port); 645 if (tty) { 646 usb_serial_handle_dcd_change(port, tty, 647 status & CH341_BIT_DCD); 648 tty_kref_put(tty); 649 } 650 } 651 652 wake_up_interruptible(&port->port.delta_msr_wait); 653 } 654 655 static void ch341_read_int_callback(struct urb *urb) 656 { 657 struct usb_serial_port *port = urb->context; 658 unsigned char *data = urb->transfer_buffer; 659 unsigned int len = urb->actual_length; 660 int status; 661 662 switch (urb->status) { 663 case 0: 664 /* success */ 665 break; 666 case -ECONNRESET: 667 case -ENOENT: 668 case -ESHUTDOWN: 669 /* this urb is terminated, clean up */ 670 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n", 671 __func__, urb->status); 672 return; 673 default: 674 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n", 675 __func__, urb->status); 676 goto exit; 677 } 678 679 usb_serial_debug_data(&port->dev, __func__, len, data); 680 ch341_update_status(port, data, len); 681 exit: 682 status = usb_submit_urb(urb, GFP_ATOMIC); 683 if (status) { 684 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n", 685 __func__, status); 686 } 687 } 688 689 static int ch341_tiocmget(struct tty_struct *tty) 690 { 691 struct usb_serial_port *port = tty->driver_data; 692 struct ch341_private *priv = usb_get_serial_port_data(port); 693 unsigned long flags; 694 u8 mcr; 695 u8 status; 696 unsigned int result; 697 698 spin_lock_irqsave(&priv->lock, flags); 699 mcr = priv->mcr; 700 status = priv->msr; 701 spin_unlock_irqrestore(&priv->lock, flags); 702 703 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0) 704 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0) 705 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0) 706 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0) 707 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0) 708 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0); 709 710 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result); 711 712 return result; 713 } 714 715 static int ch341_reset_resume(struct usb_serial *serial) 716 { 717 struct usb_serial_port *port = serial->port[0]; 718 struct ch341_private *priv; 719 int ret; 720 721 priv = usb_get_serial_port_data(port); 722 if (!priv) 723 return 0; 724 725 /* reconfigure ch341 serial port after bus-reset */ 726 ch341_configure(serial->dev, priv); 727 728 if (tty_port_initialized(&port->port)) { 729 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO); 730 if (ret) { 731 dev_err(&port->dev, "failed to submit interrupt urb: %d\n", 732 ret); 733 return ret; 734 } 735 736 ret = ch341_get_status(port->serial->dev, priv); 737 if (ret < 0) { 738 dev_err(&port->dev, "failed to read modem status: %d\n", 739 ret); 740 } 741 } 742 743 return usb_serial_generic_resume(serial); 744 } 745 746 static struct usb_serial_driver ch341_device = { 747 .driver = { 748 .owner = THIS_MODULE, 749 .name = "ch341-uart", 750 }, 751 .id_table = id_table, 752 .num_ports = 1, 753 .open = ch341_open, 754 .dtr_rts = ch341_dtr_rts, 755 .carrier_raised = ch341_carrier_raised, 756 .close = ch341_close, 757 .set_termios = ch341_set_termios, 758 .break_ctl = ch341_break_ctl, 759 .tiocmget = ch341_tiocmget, 760 .tiocmset = ch341_tiocmset, 761 .tiocmiwait = usb_serial_generic_tiocmiwait, 762 .read_int_callback = ch341_read_int_callback, 763 .port_probe = ch341_port_probe, 764 .port_remove = ch341_port_remove, 765 .reset_resume = ch341_reset_resume, 766 }; 767 768 static struct usb_serial_driver * const serial_drivers[] = { 769 &ch341_device, NULL 770 }; 771 772 module_usb_serial_driver(serial_drivers, id_table); 773 774 MODULE_LICENSE("GPL v2"); 775