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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_PRESCALER 0x12
63#define CH341_REG_DIVISOR 0x13
64#define CH341_REG_LCR 0x18
65#define CH341_REG_LCR2 0x25
66
67#define CH341_NBREAK_BITS 0x01
68
69#define CH341_LCR_ENABLE_RX 0x80
70#define CH341_LCR_ENABLE_TX 0x40
71#define CH341_LCR_MARK_SPACE 0x20
72#define CH341_LCR_PAR_EVEN 0x10
73#define CH341_LCR_ENABLE_PAR 0x08
74#define CH341_LCR_STOP_BITS_2 0x04
75#define CH341_LCR_CS8 0x03
76#define CH341_LCR_CS7 0x02
77#define CH341_LCR_CS6 0x01
78#define CH341_LCR_CS5 0x00
79
80#define CH341_QUIRK_LIMITED_PRESCALER BIT(0)
81#define CH341_QUIRK_SIMULATE_BREAK BIT(1)
82
83static const struct usb_device_id id_table[] = {
84 { USB_DEVICE(0x1a86, 0x5523) },
85 { USB_DEVICE(0x1a86, 0x7522) },
86 { USB_DEVICE(0x1a86, 0x7523) },
87 { USB_DEVICE(0x2184, 0x0057) },
88 { USB_DEVICE(0x4348, 0x5523) },
89 { USB_DEVICE(0x9986, 0x7523) },
90 { },
91};
92MODULE_DEVICE_TABLE(usb, id_table);
93
94struct ch341_private {
95 spinlock_t lock; /* access lock */
96 unsigned baud_rate; /* set baud rate */
97 u8 mcr;
98 u8 msr;
99 u8 lcr;
100
101 unsigned long quirks;
102 u8 version;
103
104 unsigned long break_end;
105};
106
107static void ch341_set_termios(struct tty_struct *tty,
108 struct usb_serial_port *port,
109 const struct ktermios *old_termios);
110
111static int ch341_control_out(struct usb_device *dev, u8 request,
112 u16 value, u16 index)
113{
114 int r;
115
116 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
117 request, value, index);
118
119 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
120 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
121 value, index, NULL, 0, DEFAULT_TIMEOUT);
122 if (r < 0)
123 dev_err(&dev->dev, "failed to send control message: %d\n", r);
124
125 return r;
126}
127
128static int ch341_control_in(struct usb_device *dev,
129 u8 request, u16 value, u16 index,
130 char *buf, unsigned bufsize)
131{
132 int r;
133
134 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
135 request, value, index, bufsize);
136
137 r = usb_control_msg_recv(dev, 0, request,
138 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
139 value, index, buf, bufsize, DEFAULT_TIMEOUT,
140 GFP_KERNEL);
141 if (r) {
142 dev_err(&dev->dev, "failed to receive control message: %d\n",
143 r);
144 return r;
145 }
146
147 return 0;
148}
149
150#define CH341_CLKRATE 48000000
151#define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact)))
152#define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512))
153
154static const speed_t ch341_min_rates[] = {
155 CH341_MIN_RATE(0),
156 CH341_MIN_RATE(1),
157 CH341_MIN_RATE(2),
158 CH341_MIN_RATE(3),
159};
160
161/* Supported range is 46 to 3000000 bps. */
162#define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
163#define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2))
164
165/*
166 * The device line speed is given by the following equation:
167 *
168 * baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where
169 *
170 * 0 <= ps <= 3,
171 * 0 <= fact <= 1,
172 * 2 <= div <= 256 if fact = 0, or
173 * 9 <= div <= 256 if fact = 1
174 */
175static int ch341_get_divisor(struct ch341_private *priv, speed_t speed)
176{
177 unsigned int fact, div, clk_div;
178 bool force_fact0 = false;
179 int ps;
180
181 /*
182 * Clamp to supported range, this makes the (ps < 0) and (div < 2)
183 * sanity checks below redundant.
184 */
185 speed = clamp_val(speed, CH341_MIN_BPS, CH341_MAX_BPS);
186
187 /*
188 * Start with highest possible base clock (fact = 1) that will give a
189 * divisor strictly less than 512.
190 */
191 fact = 1;
192 for (ps = 3; ps >= 0; ps--) {
193 if (speed > ch341_min_rates[ps])
194 break;
195 }
196
197 if (ps < 0)
198 return -EINVAL;
199
200 /* Determine corresponding divisor, rounding down. */
201 clk_div = CH341_CLK_DIV(ps, fact);
202 div = CH341_CLKRATE / (clk_div * speed);
203
204 /* Some devices require a lower base clock if ps < 3. */
205 if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER))
206 force_fact0 = true;
207
208 /* Halve base clock (fact = 0) if required. */
209 if (div < 9 || div > 255 || force_fact0) {
210 div /= 2;
211 clk_div *= 2;
212 fact = 0;
213 }
214
215 if (div < 2)
216 return -EINVAL;
217
218 /*
219 * Pick next divisor if resulting rate is closer to the requested one,
220 * scale up to avoid rounding errors on low rates.
221 */
222 if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >=
223 16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1)))
224 div++;
225
226 /*
227 * Prefer lower base clock (fact = 0) if even divisor.
228 *
229 * Note that this makes the receiver more tolerant to errors.
230 */
231 if (fact == 1 && div % 2 == 0) {
232 div /= 2;
233 fact = 0;
234 }
235
236 return (0x100 - div) << 8 | fact << 2 | ps;
237}
238
239static int ch341_set_baudrate_lcr(struct usb_device *dev,
240 struct ch341_private *priv,
241 speed_t baud_rate, u8 lcr)
242{
243 int val;
244 int r;
245
246 if (!baud_rate)
247 return -EINVAL;
248
249 val = ch341_get_divisor(priv, baud_rate);
250 if (val < 0)
251 return -EINVAL;
252
253 /*
254 * CH341A buffers data until a full endpoint-size packet (32 bytes)
255 * has been received unless bit 7 is set.
256 *
257 * At least one device with version 0x27 appears to have this bit
258 * inverted.
259 */
260 if (priv->version > 0x27)
261 val |= BIT(7);
262
263 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
264 CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER,
265 val);
266 if (r)
267 return r;
268
269 /*
270 * Chip versions before version 0x30 as read using
271 * CH341_REQ_READ_VERSION used separate registers for line control
272 * (stop bits, parity and word length). Version 0x30 and above use
273 * CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero.
274 */
275 if (priv->version < 0x30)
276 return 0;
277
278 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
279 CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr);
280 if (r)
281 return r;
282
283 return r;
284}
285
286static int ch341_set_handshake(struct usb_device *dev, u8 control)
287{
288 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
289}
290
291static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
292{
293 const unsigned int size = 2;
294 u8 buffer[2];
295 int r;
296 unsigned long flags;
297
298 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
299 if (r)
300 return r;
301
302 spin_lock_irqsave(&priv->lock, flags);
303 priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
304 spin_unlock_irqrestore(&priv->lock, flags);
305
306 return 0;
307}
308
309/* -------------------------------------------------------------------------- */
310
311static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
312{
313 const unsigned int size = 2;
314 u8 buffer[2];
315 int r;
316
317 /* expect two bytes 0x27 0x00 */
318 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
319 if (r)
320 return r;
321
322 priv->version = buffer[0];
323 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", priv->version);
324
325 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
326 if (r < 0)
327 return r;
328
329 r = ch341_set_baudrate_lcr(dev, priv, priv->baud_rate, priv->lcr);
330 if (r < 0)
331 return r;
332
333 r = ch341_set_handshake(dev, priv->mcr);
334 if (r < 0)
335 return r;
336
337 return 0;
338}
339
340static int ch341_detect_quirks(struct usb_serial_port *port)
341{
342 struct ch341_private *priv = usb_get_serial_port_data(port);
343 struct usb_device *udev = port->serial->dev;
344 const unsigned int size = 2;
345 unsigned long quirks = 0;
346 u8 buffer[2];
347 int r;
348
349 /*
350 * A subset of CH34x devices does not support all features. The
351 * prescaler is limited and there is no support for sending a RS232
352 * break condition. A read failure when trying to set up the latter is
353 * used to detect these devices.
354 */
355 r = usb_control_msg_recv(udev, 0, CH341_REQ_READ_REG,
356 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
357 CH341_REG_BREAK, 0, &buffer, size,
358 DEFAULT_TIMEOUT, GFP_KERNEL);
359 if (r == -EPIPE) {
360 dev_info(&port->dev, "break control not supported, using simulated break\n");
361 quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK;
362 r = 0;
363 } else if (r) {
364 dev_err(&port->dev, "failed to read break control: %d\n", r);
365 }
366
367 if (quirks) {
368 dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks);
369 priv->quirks |= quirks;
370 }
371
372 return r;
373}
374
375static int ch341_port_probe(struct usb_serial_port *port)
376{
377 struct ch341_private *priv;
378 int r;
379
380 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
381 if (!priv)
382 return -ENOMEM;
383
384 spin_lock_init(&priv->lock);
385 priv->baud_rate = DEFAULT_BAUD_RATE;
386 /*
387 * Some CH340 devices appear unable to change the initial LCR
388 * settings, so set a sane 8N1 default.
389 */
390 priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
391
392 r = ch341_configure(port->serial->dev, priv);
393 if (r < 0)
394 goto error;
395
396 usb_set_serial_port_data(port, priv);
397
398 r = ch341_detect_quirks(port);
399 if (r < 0)
400 goto error;
401
402 return 0;
403
404error: kfree(priv);
405 return r;
406}
407
408static void ch341_port_remove(struct usb_serial_port *port)
409{
410 struct ch341_private *priv;
411
412 priv = usb_get_serial_port_data(port);
413 kfree(priv);
414}
415
416static int ch341_carrier_raised(struct usb_serial_port *port)
417{
418 struct ch341_private *priv = usb_get_serial_port_data(port);
419 if (priv->msr & CH341_BIT_DCD)
420 return 1;
421 return 0;
422}
423
424static void ch341_dtr_rts(struct usb_serial_port *port, int on)
425{
426 struct ch341_private *priv = usb_get_serial_port_data(port);
427 unsigned long flags;
428
429 /* drop DTR and RTS */
430 spin_lock_irqsave(&priv->lock, flags);
431 if (on)
432 priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
433 else
434 priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
435 spin_unlock_irqrestore(&priv->lock, flags);
436 ch341_set_handshake(port->serial->dev, priv->mcr);
437}
438
439static void ch341_close(struct usb_serial_port *port)
440{
441 usb_serial_generic_close(port);
442 usb_kill_urb(port->interrupt_in_urb);
443}
444
445
446/* open this device, set default parameters */
447static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
448{
449 struct ch341_private *priv = usb_get_serial_port_data(port);
450 int r;
451
452 if (tty)
453 ch341_set_termios(tty, port, NULL);
454
455 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
456 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
457 if (r) {
458 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
459 __func__, r);
460 return r;
461 }
462
463 r = ch341_get_status(port->serial->dev, priv);
464 if (r < 0) {
465 dev_err(&port->dev, "failed to read modem status: %d\n", r);
466 goto err_kill_interrupt_urb;
467 }
468
469 r = usb_serial_generic_open(tty, port);
470 if (r)
471 goto err_kill_interrupt_urb;
472
473 return 0;
474
475err_kill_interrupt_urb:
476 usb_kill_urb(port->interrupt_in_urb);
477
478 return r;
479}
480
481/* Old_termios contains the original termios settings and
482 * tty->termios contains the new setting to be used.
483 */
484static void ch341_set_termios(struct tty_struct *tty,
485 struct usb_serial_port *port,
486 const struct ktermios *old_termios)
487{
488 struct ch341_private *priv = usb_get_serial_port_data(port);
489 unsigned baud_rate;
490 unsigned long flags;
491 u8 lcr;
492 int r;
493
494 /* redundant changes may cause the chip to lose bytes */
495 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
496 return;
497
498 baud_rate = tty_get_baud_rate(tty);
499
500 lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
501
502 switch (C_CSIZE(tty)) {
503 case CS5:
504 lcr |= CH341_LCR_CS5;
505 break;
506 case CS6:
507 lcr |= CH341_LCR_CS6;
508 break;
509 case CS7:
510 lcr |= CH341_LCR_CS7;
511 break;
512 case CS8:
513 lcr |= CH341_LCR_CS8;
514 break;
515 }
516
517 if (C_PARENB(tty)) {
518 lcr |= CH341_LCR_ENABLE_PAR;
519 if (C_PARODD(tty) == 0)
520 lcr |= CH341_LCR_PAR_EVEN;
521 if (C_CMSPAR(tty))
522 lcr |= CH341_LCR_MARK_SPACE;
523 }
524
525 if (C_CSTOPB(tty))
526 lcr |= CH341_LCR_STOP_BITS_2;
527
528 if (baud_rate) {
529 priv->baud_rate = baud_rate;
530
531 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
532 priv->baud_rate, lcr);
533 if (r < 0 && old_termios) {
534 priv->baud_rate = tty_termios_baud_rate(old_termios);
535 tty_termios_copy_hw(&tty->termios, old_termios);
536 } else if (r == 0) {
537 priv->lcr = lcr;
538 }
539 }
540
541 spin_lock_irqsave(&priv->lock, flags);
542 if (C_BAUD(tty) == B0)
543 priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
544 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
545 priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
546 spin_unlock_irqrestore(&priv->lock, flags);
547
548 ch341_set_handshake(port->serial->dev, priv->mcr);
549}
550
551/*
552 * A subset of all CH34x devices don't support a real break condition and
553 * reading CH341_REG_BREAK fails (see also ch341_detect_quirks). This function
554 * simulates a break condition by lowering the baud rate to the minimum
555 * supported by the hardware upon enabling the break condition and sending
556 * a NUL byte.
557 *
558 * Incoming data is corrupted while the break condition is being simulated.
559 *
560 * Normally the duration of the break condition can be controlled individually
561 * by userspace using TIOCSBRK and TIOCCBRK or by passing an argument to
562 * TCSBRKP. Due to how the simulation is implemented the duration can't be
563 * controlled. The duration is always about (1s / 46bd * 9bit) = 196ms.
564 */
565static int ch341_simulate_break(struct tty_struct *tty, int break_state)
566{
567 struct usb_serial_port *port = tty->driver_data;
568 struct ch341_private *priv = usb_get_serial_port_data(port);
569 unsigned long now, delay;
570 int r, r2;
571
572 if (break_state != 0) {
573 dev_dbg(&port->dev, "enter break state requested\n");
574
575 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
576 CH341_MIN_BPS,
577 CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8);
578 if (r < 0) {
579 dev_err(&port->dev,
580 "failed to change baud rate to %u: %d\n",
581 CH341_MIN_BPS, r);
582 goto restore;
583 }
584
585 r = tty_put_char(tty, '\0');
586 if (r < 0) {
587 dev_err(&port->dev,
588 "failed to write NUL byte for simulated break condition: %d\n",
589 r);
590 goto restore;
591 }
592
593 /*
594 * Compute expected transmission duration including safety
595 * margin. The original baud rate is only restored after the
596 * computed point in time.
597 *
598 * 11 bits = 1 start, 8 data, 1 stop, 1 margin
599 */
600 priv->break_end = jiffies + (11 * HZ / CH341_MIN_BPS);
601
602 return 0;
603 }
604
605 dev_dbg(&port->dev, "leave break state requested\n");
606
607 now = jiffies;
608
609 if (time_before(now, priv->break_end)) {
610 /* Wait until NUL byte is written */
611 delay = priv->break_end - now;
612 dev_dbg(&port->dev,
613 "wait %d ms while transmitting NUL byte at %u baud\n",
614 jiffies_to_msecs(delay), CH341_MIN_BPS);
615 schedule_timeout_interruptible(delay);
616 }
617
618 r = 0;
619restore:
620 /* Restore original baud rate */
621 r2 = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate,
622 priv->lcr);
623 if (r2 < 0) {
624 dev_err(&port->dev,
625 "restoring original baud rate of %u failed: %d\n",
626 priv->baud_rate, r2);
627 return r2;
628 }
629
630 return r;
631}
632
633static int ch341_break_ctl(struct tty_struct *tty, int break_state)
634{
635 const uint16_t ch341_break_reg =
636 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
637 struct usb_serial_port *port = tty->driver_data;
638 struct ch341_private *priv = usb_get_serial_port_data(port);
639 int r;
640 uint16_t reg_contents;
641 uint8_t break_reg[2];
642
643 if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK)
644 return ch341_simulate_break(tty, break_state);
645
646 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
647 ch341_break_reg, 0, break_reg, 2);
648 if (r) {
649 dev_err(&port->dev, "%s - USB control read error (%d)\n",
650 __func__, r);
651 if (r > 0)
652 r = -EIO;
653 return r;
654 }
655 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
656 __func__, break_reg[0], break_reg[1]);
657 if (break_state != 0) {
658 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
659 break_reg[0] &= ~CH341_NBREAK_BITS;
660 break_reg[1] &= ~CH341_LCR_ENABLE_TX;
661 } else {
662 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
663 break_reg[0] |= CH341_NBREAK_BITS;
664 break_reg[1] |= CH341_LCR_ENABLE_TX;
665 }
666 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
667 __func__, break_reg[0], break_reg[1]);
668 reg_contents = get_unaligned_le16(break_reg);
669 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
670 ch341_break_reg, reg_contents);
671 if (r < 0) {
672 dev_err(&port->dev, "%s - USB control write error (%d)\n",
673 __func__, r);
674 return r;
675 }
676
677 return 0;
678}
679
680static int ch341_tiocmset(struct tty_struct *tty,
681 unsigned int set, unsigned int clear)
682{
683 struct usb_serial_port *port = tty->driver_data;
684 struct ch341_private *priv = usb_get_serial_port_data(port);
685 unsigned long flags;
686 u8 control;
687
688 spin_lock_irqsave(&priv->lock, flags);
689 if (set & TIOCM_RTS)
690 priv->mcr |= CH341_BIT_RTS;
691 if (set & TIOCM_DTR)
692 priv->mcr |= CH341_BIT_DTR;
693 if (clear & TIOCM_RTS)
694 priv->mcr &= ~CH341_BIT_RTS;
695 if (clear & TIOCM_DTR)
696 priv->mcr &= ~CH341_BIT_DTR;
697 control = priv->mcr;
698 spin_unlock_irqrestore(&priv->lock, flags);
699
700 return ch341_set_handshake(port->serial->dev, control);
701}
702
703static void ch341_update_status(struct usb_serial_port *port,
704 unsigned char *data, size_t len)
705{
706 struct ch341_private *priv = usb_get_serial_port_data(port);
707 struct tty_struct *tty;
708 unsigned long flags;
709 u8 status;
710 u8 delta;
711
712 if (len < 4)
713 return;
714
715 status = ~data[2] & CH341_BITS_MODEM_STAT;
716
717 spin_lock_irqsave(&priv->lock, flags);
718 delta = status ^ priv->msr;
719 priv->msr = status;
720 spin_unlock_irqrestore(&priv->lock, flags);
721
722 if (data[1] & CH341_MULT_STAT)
723 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
724
725 if (!delta)
726 return;
727
728 if (delta & CH341_BIT_CTS)
729 port->icount.cts++;
730 if (delta & CH341_BIT_DSR)
731 port->icount.dsr++;
732 if (delta & CH341_BIT_RI)
733 port->icount.rng++;
734 if (delta & CH341_BIT_DCD) {
735 port->icount.dcd++;
736 tty = tty_port_tty_get(&port->port);
737 if (tty) {
738 usb_serial_handle_dcd_change(port, tty,
739 status & CH341_BIT_DCD);
740 tty_kref_put(tty);
741 }
742 }
743
744 wake_up_interruptible(&port->port.delta_msr_wait);
745}
746
747static void ch341_read_int_callback(struct urb *urb)
748{
749 struct usb_serial_port *port = urb->context;
750 unsigned char *data = urb->transfer_buffer;
751 unsigned int len = urb->actual_length;
752 int status;
753
754 switch (urb->status) {
755 case 0:
756 /* success */
757 break;
758 case -ECONNRESET:
759 case -ENOENT:
760 case -ESHUTDOWN:
761 /* this urb is terminated, clean up */
762 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
763 __func__, urb->status);
764 return;
765 default:
766 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
767 __func__, urb->status);
768 goto exit;
769 }
770
771 usb_serial_debug_data(&port->dev, __func__, len, data);
772 ch341_update_status(port, data, len);
773exit:
774 status = usb_submit_urb(urb, GFP_ATOMIC);
775 if (status) {
776 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
777 __func__, status);
778 }
779}
780
781static int ch341_tiocmget(struct tty_struct *tty)
782{
783 struct usb_serial_port *port = tty->driver_data;
784 struct ch341_private *priv = usb_get_serial_port_data(port);
785 unsigned long flags;
786 u8 mcr;
787 u8 status;
788 unsigned int result;
789
790 spin_lock_irqsave(&priv->lock, flags);
791 mcr = priv->mcr;
792 status = priv->msr;
793 spin_unlock_irqrestore(&priv->lock, flags);
794
795 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
796 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
797 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
798 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
799 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
800 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
801
802 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
803
804 return result;
805}
806
807static int ch341_reset_resume(struct usb_serial *serial)
808{
809 struct usb_serial_port *port = serial->port[0];
810 struct ch341_private *priv;
811 int ret;
812
813 priv = usb_get_serial_port_data(port);
814 if (!priv)
815 return 0;
816
817 /* reconfigure ch341 serial port after bus-reset */
818 ch341_configure(serial->dev, priv);
819
820 if (tty_port_initialized(&port->port)) {
821 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
822 if (ret) {
823 dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
824 ret);
825 return ret;
826 }
827
828 ret = ch341_get_status(port->serial->dev, priv);
829 if (ret < 0) {
830 dev_err(&port->dev, "failed to read modem status: %d\n",
831 ret);
832 }
833 }
834
835 return usb_serial_generic_resume(serial);
836}
837
838static struct usb_serial_driver ch341_device = {
839 .driver = {
840 .owner = THIS_MODULE,
841 .name = "ch341-uart",
842 },
843 .id_table = id_table,
844 .num_ports = 1,
845 .open = ch341_open,
846 .dtr_rts = ch341_dtr_rts,
847 .carrier_raised = ch341_carrier_raised,
848 .close = ch341_close,
849 .set_termios = ch341_set_termios,
850 .break_ctl = ch341_break_ctl,
851 .tiocmget = ch341_tiocmget,
852 .tiocmset = ch341_tiocmset,
853 .tiocmiwait = usb_serial_generic_tiocmiwait,
854 .read_int_callback = ch341_read_int_callback,
855 .port_probe = ch341_port_probe,
856 .port_remove = ch341_port_remove,
857 .reset_resume = ch341_reset_resume,
858};
859
860static struct usb_serial_driver * const serial_drivers[] = {
861 &ch341_device, NULL
862};
863
864module_usb_serial_driver(serial_drivers, id_table);
865
866MODULE_LICENSE("GPL v2");
1/*
2 * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
3 * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
4 * Copyright 2009, Boris Hajduk <boris@hajduk.org>
5 *
6 * ch341.c implements a serial port driver for the Winchiphead CH341.
7 *
8 * The CH341 device can be used to implement an RS232 asynchronous
9 * serial port, an IEEE-1284 parallel printer port or a memory-like
10 * interface. In all cases the CH341 supports an I2C interface as well.
11 * This driver only supports the asynchronous serial interface.
12 *
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License version
15 * 2 as published by the Free Software Foundation.
16 */
17
18#include <linux/kernel.h>
19#include <linux/init.h>
20#include <linux/tty.h>
21#include <linux/module.h>
22#include <linux/slab.h>
23#include <linux/usb.h>
24#include <linux/usb/serial.h>
25#include <linux/serial.h>
26#include <asm/unaligned.h>
27
28#define DEFAULT_BAUD_RATE 9600
29#define DEFAULT_TIMEOUT 1000
30
31/* flags for IO-Bits */
32#define CH341_BIT_RTS (1 << 6)
33#define CH341_BIT_DTR (1 << 5)
34
35/******************************/
36/* interrupt pipe definitions */
37/******************************/
38/* always 4 interrupt bytes */
39/* first irq byte normally 0x08 */
40/* second irq byte base 0x7d + below */
41/* third irq byte base 0x94 + below */
42/* fourth irq byte normally 0xee */
43
44/* second interrupt byte */
45#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
46
47/* status returned in third interrupt answer byte, inverted in data
48 from irq */
49#define CH341_BIT_CTS 0x01
50#define CH341_BIT_DSR 0x02
51#define CH341_BIT_RI 0x04
52#define CH341_BIT_DCD 0x08
53#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
54
55/*******************************/
56/* baudrate calculation factor */
57/*******************************/
58#define CH341_BAUDBASE_FACTOR 1532620800
59#define CH341_BAUDBASE_DIVMAX 3
60
61/* Break support - the information used to implement this was gleaned from
62 * the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
63 */
64
65#define CH341_REQ_WRITE_REG 0x9A
66#define CH341_REQ_READ_REG 0x95
67#define CH341_REG_BREAK1 0x05
68#define CH341_REG_BREAK2 0x18
69#define CH341_NBREAK_BITS_REG1 0x01
70#define CH341_NBREAK_BITS_REG2 0x40
71
72
73static bool debug;
74
75static const struct usb_device_id id_table[] = {
76 { USB_DEVICE(0x4348, 0x5523) },
77 { USB_DEVICE(0x1a86, 0x7523) },
78 { USB_DEVICE(0x1a86, 0x5523) },
79 { },
80};
81MODULE_DEVICE_TABLE(usb, id_table);
82
83struct ch341_private {
84 spinlock_t lock; /* access lock */
85 wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
86 unsigned baud_rate; /* set baud rate */
87 u8 line_control; /* set line control value RTS/DTR */
88 u8 line_status; /* active status of modem control inputs */
89 u8 multi_status_change; /* status changed multiple since last call */
90};
91
92static int ch341_control_out(struct usb_device *dev, u8 request,
93 u16 value, u16 index)
94{
95 int r;
96 dbg("ch341_control_out(%02x,%02x,%04x,%04x)", USB_DIR_OUT|0x40,
97 (int)request, (int)value, (int)index);
98
99 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
100 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
101 value, index, NULL, 0, DEFAULT_TIMEOUT);
102
103 return r;
104}
105
106static int ch341_control_in(struct usb_device *dev,
107 u8 request, u16 value, u16 index,
108 char *buf, unsigned bufsize)
109{
110 int r;
111 dbg("ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)", USB_DIR_IN|0x40,
112 (int)request, (int)value, (int)index, buf, (int)bufsize);
113
114 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
115 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
116 value, index, buf, bufsize, DEFAULT_TIMEOUT);
117 return r;
118}
119
120static int ch341_set_baudrate(struct usb_device *dev,
121 struct ch341_private *priv)
122{
123 short a, b;
124 int r;
125 unsigned long factor;
126 short divisor;
127
128 if (!priv->baud_rate)
129 return -EINVAL;
130 factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
131 divisor = CH341_BAUDBASE_DIVMAX;
132
133 while ((factor > 0xfff0) && divisor) {
134 factor >>= 3;
135 divisor--;
136 }
137
138 if (factor > 0xfff0)
139 return -EINVAL;
140
141 factor = 0x10000 - factor;
142 a = (factor & 0xff00) | divisor;
143 b = factor & 0xff;
144
145 r = ch341_control_out(dev, 0x9a, 0x1312, a);
146 if (!r)
147 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
148
149 return r;
150}
151
152static int ch341_set_handshake(struct usb_device *dev, u8 control)
153{
154 return ch341_control_out(dev, 0xa4, ~control, 0);
155}
156
157static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
158{
159 char *buffer;
160 int r;
161 const unsigned size = 8;
162 unsigned long flags;
163
164 buffer = kmalloc(size, GFP_KERNEL);
165 if (!buffer)
166 return -ENOMEM;
167
168 r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
169 if (r < 0)
170 goto out;
171
172 /* setup the private status if available */
173 if (r == 2) {
174 r = 0;
175 spin_lock_irqsave(&priv->lock, flags);
176 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
177 priv->multi_status_change = 0;
178 spin_unlock_irqrestore(&priv->lock, flags);
179 } else
180 r = -EPROTO;
181
182out: kfree(buffer);
183 return r;
184}
185
186/* -------------------------------------------------------------------------- */
187
188static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
189{
190 char *buffer;
191 int r;
192 const unsigned size = 8;
193
194 buffer = kmalloc(size, GFP_KERNEL);
195 if (!buffer)
196 return -ENOMEM;
197
198 /* expect two bytes 0x27 0x00 */
199 r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
200 if (r < 0)
201 goto out;
202
203 r = ch341_control_out(dev, 0xa1, 0, 0);
204 if (r < 0)
205 goto out;
206
207 r = ch341_set_baudrate(dev, priv);
208 if (r < 0)
209 goto out;
210
211 /* expect two bytes 0x56 0x00 */
212 r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
213 if (r < 0)
214 goto out;
215
216 r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
217 if (r < 0)
218 goto out;
219
220 /* expect 0xff 0xee */
221 r = ch341_get_status(dev, priv);
222 if (r < 0)
223 goto out;
224
225 r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
226 if (r < 0)
227 goto out;
228
229 r = ch341_set_baudrate(dev, priv);
230 if (r < 0)
231 goto out;
232
233 r = ch341_set_handshake(dev, priv->line_control);
234 if (r < 0)
235 goto out;
236
237 /* expect 0x9f 0xee */
238 r = ch341_get_status(dev, priv);
239
240out: kfree(buffer);
241 return r;
242}
243
244/* allocate private data */
245static int ch341_attach(struct usb_serial *serial)
246{
247 struct ch341_private *priv;
248 int r;
249
250 /* private data */
251 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
252 if (!priv)
253 return -ENOMEM;
254
255 spin_lock_init(&priv->lock);
256 init_waitqueue_head(&priv->delta_msr_wait);
257 priv->baud_rate = DEFAULT_BAUD_RATE;
258 priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
259
260 r = ch341_configure(serial->dev, priv);
261 if (r < 0)
262 goto error;
263
264 usb_set_serial_port_data(serial->port[0], priv);
265 return 0;
266
267error: kfree(priv);
268 return r;
269}
270
271static int ch341_carrier_raised(struct usb_serial_port *port)
272{
273 struct ch341_private *priv = usb_get_serial_port_data(port);
274 if (priv->line_status & CH341_BIT_DCD)
275 return 1;
276 return 0;
277}
278
279static void ch341_dtr_rts(struct usb_serial_port *port, int on)
280{
281 struct ch341_private *priv = usb_get_serial_port_data(port);
282 unsigned long flags;
283
284 /* drop DTR and RTS */
285 spin_lock_irqsave(&priv->lock, flags);
286 if (on)
287 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
288 else
289 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
290 spin_unlock_irqrestore(&priv->lock, flags);
291 ch341_set_handshake(port->serial->dev, priv->line_control);
292 wake_up_interruptible(&priv->delta_msr_wait);
293}
294
295static void ch341_close(struct usb_serial_port *port)
296{
297 usb_serial_generic_close(port);
298 usb_kill_urb(port->interrupt_in_urb);
299}
300
301
302/* open this device, set default parameters */
303static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
304{
305 struct usb_serial *serial = port->serial;
306 struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
307 int r;
308
309 priv->baud_rate = DEFAULT_BAUD_RATE;
310
311 r = ch341_configure(serial->dev, priv);
312 if (r)
313 goto out;
314
315 r = ch341_set_handshake(serial->dev, priv->line_control);
316 if (r)
317 goto out;
318
319 r = ch341_set_baudrate(serial->dev, priv);
320 if (r)
321 goto out;
322
323 dbg("%s - submitting interrupt urb", __func__);
324 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
325 if (r) {
326 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
327 " error %d\n", __func__, r);
328 ch341_close(port);
329 goto out;
330 }
331
332 r = usb_serial_generic_open(tty, port);
333
334out: return r;
335}
336
337/* Old_termios contains the original termios settings and
338 * tty->termios contains the new setting to be used.
339 */
340static void ch341_set_termios(struct tty_struct *tty,
341 struct usb_serial_port *port, struct ktermios *old_termios)
342{
343 struct ch341_private *priv = usb_get_serial_port_data(port);
344 unsigned baud_rate;
345 unsigned long flags;
346
347 baud_rate = tty_get_baud_rate(tty);
348
349 priv->baud_rate = baud_rate;
350
351 if (baud_rate) {
352 spin_lock_irqsave(&priv->lock, flags);
353 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
354 spin_unlock_irqrestore(&priv->lock, flags);
355 ch341_set_baudrate(port->serial->dev, priv);
356 } else {
357 spin_lock_irqsave(&priv->lock, flags);
358 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
359 spin_unlock_irqrestore(&priv->lock, flags);
360 }
361
362 ch341_set_handshake(port->serial->dev, priv->line_control);
363
364 /* Unimplemented:
365 * (cflag & CSIZE) : data bits [5, 8]
366 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
367 * (cflag & CSTOPB) : stop bits [1, 2]
368 */
369}
370
371static void ch341_break_ctl(struct tty_struct *tty, int break_state)
372{
373 const uint16_t ch341_break_reg =
374 CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
375 struct usb_serial_port *port = tty->driver_data;
376 int r;
377 uint16_t reg_contents;
378 uint8_t *break_reg;
379
380 break_reg = kmalloc(2, GFP_KERNEL);
381 if (!break_reg) {
382 dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
383 return;
384 }
385
386 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
387 ch341_break_reg, 0, break_reg, 2);
388 if (r < 0) {
389 dev_err(&port->dev, "%s - USB control read error (%d)\n",
390 __func__, r);
391 goto out;
392 }
393 dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
394 __func__, break_reg[0], break_reg[1]);
395 if (break_state != 0) {
396 dbg("%s - Enter break state requested", __func__);
397 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
398 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
399 } else {
400 dbg("%s - Leave break state requested", __func__);
401 break_reg[0] |= CH341_NBREAK_BITS_REG1;
402 break_reg[1] |= CH341_NBREAK_BITS_REG2;
403 }
404 dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
405 __func__, break_reg[0], break_reg[1]);
406 reg_contents = get_unaligned_le16(break_reg);
407 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
408 ch341_break_reg, reg_contents);
409 if (r < 0)
410 dev_err(&port->dev, "%s - USB control write error (%d)\n",
411 __func__, r);
412out:
413 kfree(break_reg);
414}
415
416static int ch341_tiocmset(struct tty_struct *tty,
417 unsigned int set, unsigned int clear)
418{
419 struct usb_serial_port *port = tty->driver_data;
420 struct ch341_private *priv = usb_get_serial_port_data(port);
421 unsigned long flags;
422 u8 control;
423
424 spin_lock_irqsave(&priv->lock, flags);
425 if (set & TIOCM_RTS)
426 priv->line_control |= CH341_BIT_RTS;
427 if (set & TIOCM_DTR)
428 priv->line_control |= CH341_BIT_DTR;
429 if (clear & TIOCM_RTS)
430 priv->line_control &= ~CH341_BIT_RTS;
431 if (clear & TIOCM_DTR)
432 priv->line_control &= ~CH341_BIT_DTR;
433 control = priv->line_control;
434 spin_unlock_irqrestore(&priv->lock, flags);
435
436 return ch341_set_handshake(port->serial->dev, control);
437}
438
439static void ch341_read_int_callback(struct urb *urb)
440{
441 struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
442 unsigned char *data = urb->transfer_buffer;
443 unsigned int actual_length = urb->actual_length;
444 int status;
445
446 switch (urb->status) {
447 case 0:
448 /* success */
449 break;
450 case -ECONNRESET:
451 case -ENOENT:
452 case -ESHUTDOWN:
453 /* this urb is terminated, clean up */
454 dbg("%s - urb shutting down with status: %d", __func__,
455 urb->status);
456 return;
457 default:
458 dbg("%s - nonzero urb status received: %d", __func__,
459 urb->status);
460 goto exit;
461 }
462
463 usb_serial_debug_data(debug, &port->dev, __func__,
464 urb->actual_length, urb->transfer_buffer);
465
466 if (actual_length >= 4) {
467 struct ch341_private *priv = usb_get_serial_port_data(port);
468 unsigned long flags;
469 u8 prev_line_status = priv->line_status;
470
471 spin_lock_irqsave(&priv->lock, flags);
472 priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
473 if ((data[1] & CH341_MULT_STAT))
474 priv->multi_status_change = 1;
475 spin_unlock_irqrestore(&priv->lock, flags);
476
477 if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
478 struct tty_struct *tty = tty_port_tty_get(&port->port);
479 if (tty)
480 usb_serial_handle_dcd_change(port, tty,
481 priv->line_status & CH341_BIT_DCD);
482 tty_kref_put(tty);
483 }
484
485 wake_up_interruptible(&priv->delta_msr_wait);
486 }
487
488exit:
489 status = usb_submit_urb(urb, GFP_ATOMIC);
490 if (status)
491 dev_err(&urb->dev->dev,
492 "%s - usb_submit_urb failed with result %d\n",
493 __func__, status);
494}
495
496static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
497{
498 struct ch341_private *priv = usb_get_serial_port_data(port);
499 unsigned long flags;
500 u8 prevstatus;
501 u8 status;
502 u8 changed;
503 u8 multi_change = 0;
504
505 spin_lock_irqsave(&priv->lock, flags);
506 prevstatus = priv->line_status;
507 priv->multi_status_change = 0;
508 spin_unlock_irqrestore(&priv->lock, flags);
509
510 while (!multi_change) {
511 interruptible_sleep_on(&priv->delta_msr_wait);
512 /* see if a signal did it */
513 if (signal_pending(current))
514 return -ERESTARTSYS;
515
516 spin_lock_irqsave(&priv->lock, flags);
517 status = priv->line_status;
518 multi_change = priv->multi_status_change;
519 spin_unlock_irqrestore(&priv->lock, flags);
520
521 changed = prevstatus ^ status;
522
523 if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
524 ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
525 ((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) ||
526 ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
527 return 0;
528 }
529 prevstatus = status;
530 }
531
532 return 0;
533}
534
535static int ch341_ioctl(struct tty_struct *tty,
536 unsigned int cmd, unsigned long arg)
537{
538 struct usb_serial_port *port = tty->driver_data;
539 dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
540
541 switch (cmd) {
542 case TIOCMIWAIT:
543 dbg("%s (%d) TIOCMIWAIT", __func__, port->number);
544 return wait_modem_info(port, arg);
545
546 default:
547 dbg("%s not supported = 0x%04x", __func__, cmd);
548 break;
549 }
550
551 return -ENOIOCTLCMD;
552}
553
554static int ch341_tiocmget(struct tty_struct *tty)
555{
556 struct usb_serial_port *port = tty->driver_data;
557 struct ch341_private *priv = usb_get_serial_port_data(port);
558 unsigned long flags;
559 u8 mcr;
560 u8 status;
561 unsigned int result;
562
563 spin_lock_irqsave(&priv->lock, flags);
564 mcr = priv->line_control;
565 status = priv->line_status;
566 spin_unlock_irqrestore(&priv->lock, flags);
567
568 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
569 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
570 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
571 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
572 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
573 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
574
575 dbg("%s - result = %x", __func__, result);
576
577 return result;
578}
579
580static int ch341_reset_resume(struct usb_serial *serial)
581{
582 struct ch341_private *priv;
583
584 priv = usb_get_serial_port_data(serial->port[0]);
585
586 /* reconfigure ch341 serial port after bus-reset */
587 ch341_configure(serial->dev, priv);
588
589 return 0;
590}
591
592static struct usb_serial_driver ch341_device = {
593 .driver = {
594 .owner = THIS_MODULE,
595 .name = "ch341-uart",
596 },
597 .id_table = id_table,
598 .num_ports = 1,
599 .open = ch341_open,
600 .dtr_rts = ch341_dtr_rts,
601 .carrier_raised = ch341_carrier_raised,
602 .close = ch341_close,
603 .ioctl = ch341_ioctl,
604 .set_termios = ch341_set_termios,
605 .break_ctl = ch341_break_ctl,
606 .tiocmget = ch341_tiocmget,
607 .tiocmset = ch341_tiocmset,
608 .read_int_callback = ch341_read_int_callback,
609 .attach = ch341_attach,
610 .reset_resume = ch341_reset_resume,
611};
612
613static struct usb_serial_driver * const serial_drivers[] = {
614 &ch341_device, NULL
615};
616
617module_usb_serial_driver(serial_drivers, id_table);
618
619MODULE_LICENSE("GPL");
620
621module_param(debug, bool, S_IRUGO | S_IWUSR);
622MODULE_PARM_DESC(debug, "Debug enabled or not");