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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/tty.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22#include <linux/usb.h>
23#include <linux/usb/serial.h>
24#include <linux/serial.h>
25#include <asm/unaligned.h>
26
27#define DEFAULT_BAUD_RATE 9600
28#define DEFAULT_TIMEOUT 1000
29
30/* flags for IO-Bits */
31#define CH341_BIT_RTS (1 << 6)
32#define CH341_BIT_DTR (1 << 5)
33
34/******************************/
35/* interrupt pipe definitions */
36/******************************/
37/* always 4 interrupt bytes */
38/* first irq byte normally 0x08 */
39/* second irq byte base 0x7d + below */
40/* third irq byte base 0x94 + below */
41/* fourth irq byte normally 0xee */
42
43/* second interrupt byte */
44#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
45
46/* status returned in third interrupt answer byte, inverted in data
47 from irq */
48#define CH341_BIT_CTS 0x01
49#define CH341_BIT_DSR 0x02
50#define CH341_BIT_RI 0x04
51#define CH341_BIT_DCD 0x08
52#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
53
54/*******************************/
55/* baudrate calculation factor */
56/*******************************/
57#define CH341_BAUDBASE_FACTOR 1532620800
58#define CH341_BAUDBASE_DIVMAX 3
59
60/* Break support - the information used to implement this was gleaned from
61 * the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato.
62 */
63
64#define CH341_REQ_WRITE_REG 0x9A
65#define CH341_REQ_READ_REG 0x95
66#define CH341_REG_BREAK1 0x05
67#define CH341_REG_BREAK2 0x18
68#define CH341_NBREAK_BITS_REG1 0x01
69#define CH341_NBREAK_BITS_REG2 0x40
70
71
72static const struct usb_device_id id_table[] = {
73 { USB_DEVICE(0x4348, 0x5523) },
74 { USB_DEVICE(0x1a86, 0x7523) },
75 { USB_DEVICE(0x1a86, 0x5523) },
76 { },
77};
78MODULE_DEVICE_TABLE(usb, id_table);
79
80struct ch341_private {
81 spinlock_t lock; /* access lock */
82 unsigned baud_rate; /* set baud rate */
83 u8 line_control; /* set line control value RTS/DTR */
84 u8 line_status; /* active status of modem control inputs */
85};
86
87static void ch341_set_termios(struct tty_struct *tty,
88 struct usb_serial_port *port,
89 struct ktermios *old_termios);
90
91static int ch341_control_out(struct usb_device *dev, u8 request,
92 u16 value, u16 index)
93{
94 int r;
95
96 dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
97 USB_DIR_OUT|0x40, (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
112 dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
113 USB_DIR_IN|0x40, (int)request, (int)value, (int)index, buf,
114 (int)bufsize);
115
116 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
117 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
118 value, index, buf, bufsize, DEFAULT_TIMEOUT);
119 return r;
120}
121
122static int ch341_set_baudrate(struct usb_device *dev,
123 struct ch341_private *priv)
124{
125 short a, b;
126 int r;
127 unsigned long factor;
128 short divisor;
129
130 if (!priv->baud_rate)
131 return -EINVAL;
132 factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
133 divisor = CH341_BAUDBASE_DIVMAX;
134
135 while ((factor > 0xfff0) && divisor) {
136 factor >>= 3;
137 divisor--;
138 }
139
140 if (factor > 0xfff0)
141 return -EINVAL;
142
143 factor = 0x10000 - factor;
144 a = (factor & 0xff00) | divisor;
145 b = factor & 0xff;
146
147 r = ch341_control_out(dev, 0x9a, 0x1312, a);
148 if (!r)
149 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
150
151 return r;
152}
153
154static int ch341_set_handshake(struct usb_device *dev, u8 control)
155{
156 return ch341_control_out(dev, 0xa4, ~control, 0);
157}
158
159static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
160{
161 char *buffer;
162 int r;
163 const unsigned size = 8;
164 unsigned long flags;
165
166 buffer = kmalloc(size, GFP_KERNEL);
167 if (!buffer)
168 return -ENOMEM;
169
170 r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
171 if (r < 0)
172 goto out;
173
174 /* setup the private status if available */
175 if (r == 2) {
176 r = 0;
177 spin_lock_irqsave(&priv->lock, flags);
178 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
179 spin_unlock_irqrestore(&priv->lock, flags);
180 } else
181 r = -EPROTO;
182
183out: kfree(buffer);
184 return r;
185}
186
187/* -------------------------------------------------------------------------- */
188
189static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
190{
191 char *buffer;
192 int r;
193 const unsigned size = 8;
194
195 buffer = kmalloc(size, GFP_KERNEL);
196 if (!buffer)
197 return -ENOMEM;
198
199 /* expect two bytes 0x27 0x00 */
200 r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
201 if (r < 0)
202 goto out;
203
204 r = ch341_control_out(dev, 0xa1, 0, 0);
205 if (r < 0)
206 goto out;
207
208 r = ch341_set_baudrate(dev, priv);
209 if (r < 0)
210 goto out;
211
212 /* expect two bytes 0x56 0x00 */
213 r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
214 if (r < 0)
215 goto out;
216
217 r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
218 if (r < 0)
219 goto out;
220
221 /* expect 0xff 0xee */
222 r = ch341_get_status(dev, priv);
223 if (r < 0)
224 goto out;
225
226 r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
227 if (r < 0)
228 goto out;
229
230 r = ch341_set_baudrate(dev, priv);
231 if (r < 0)
232 goto out;
233
234 r = ch341_set_handshake(dev, priv->line_control);
235 if (r < 0)
236 goto out;
237
238 /* expect 0x9f 0xee */
239 r = ch341_get_status(dev, priv);
240
241out: kfree(buffer);
242 return r;
243}
244
245static int ch341_port_probe(struct usb_serial_port *port)
246{
247 struct ch341_private *priv;
248 int r;
249
250 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
251 if (!priv)
252 return -ENOMEM;
253
254 spin_lock_init(&priv->lock);
255 priv->baud_rate = DEFAULT_BAUD_RATE;
256 priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
257
258 r = ch341_configure(port->serial->dev, priv);
259 if (r < 0)
260 goto error;
261
262 usb_set_serial_port_data(port, priv);
263 return 0;
264
265error: kfree(priv);
266 return r;
267}
268
269static int ch341_port_remove(struct usb_serial_port *port)
270{
271 struct ch341_private *priv;
272
273 priv = usb_get_serial_port_data(port);
274 kfree(priv);
275
276 return 0;
277}
278
279static int ch341_carrier_raised(struct usb_serial_port *port)
280{
281 struct ch341_private *priv = usb_get_serial_port_data(port);
282 if (priv->line_status & CH341_BIT_DCD)
283 return 1;
284 return 0;
285}
286
287static void ch341_dtr_rts(struct usb_serial_port *port, int on)
288{
289 struct ch341_private *priv = usb_get_serial_port_data(port);
290 unsigned long flags;
291
292 /* drop DTR and RTS */
293 spin_lock_irqsave(&priv->lock, flags);
294 if (on)
295 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
296 else
297 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
298 spin_unlock_irqrestore(&priv->lock, flags);
299 ch341_set_handshake(port->serial->dev, priv->line_control);
300}
301
302static void ch341_close(struct usb_serial_port *port)
303{
304 usb_serial_generic_close(port);
305 usb_kill_urb(port->interrupt_in_urb);
306}
307
308
309/* open this device, set default parameters */
310static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
311{
312 struct usb_serial *serial = port->serial;
313 struct ch341_private *priv = usb_get_serial_port_data(port);
314 int r;
315
316 r = ch341_configure(serial->dev, priv);
317 if (r)
318 goto out;
319
320 if (tty)
321 ch341_set_termios(tty, port, NULL);
322
323 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
324 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
325 if (r) {
326 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
327 __func__, r);
328 goto out;
329 }
330
331 r = usb_serial_generic_open(tty, port);
332
333out: return r;
334}
335
336/* Old_termios contains the original termios settings and
337 * tty->termios contains the new setting to be used.
338 */
339static void ch341_set_termios(struct tty_struct *tty,
340 struct usb_serial_port *port, struct ktermios *old_termios)
341{
342 struct ch341_private *priv = usb_get_serial_port_data(port);
343 unsigned baud_rate;
344 unsigned long flags;
345
346 baud_rate = tty_get_baud_rate(tty);
347
348 priv->baud_rate = baud_rate;
349
350 if (baud_rate) {
351 spin_lock_irqsave(&priv->lock, flags);
352 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
353 spin_unlock_irqrestore(&priv->lock, flags);
354 ch341_set_baudrate(port->serial->dev, priv);
355 } else {
356 spin_lock_irqsave(&priv->lock, flags);
357 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
358 spin_unlock_irqrestore(&priv->lock, flags);
359 }
360
361 ch341_set_handshake(port->serial->dev, priv->line_control);
362
363 /* Unimplemented:
364 * (cflag & CSIZE) : data bits [5, 8]
365 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
366 * (cflag & CSTOPB) : stop bits [1, 2]
367 */
368}
369
370static void ch341_break_ctl(struct tty_struct *tty, int break_state)
371{
372 const uint16_t ch341_break_reg =
373 ((uint16_t) CH341_REG_BREAK2 << 8) | CH341_REG_BREAK1;
374 struct usb_serial_port *port = tty->driver_data;
375 int r;
376 uint16_t reg_contents;
377 uint8_t *break_reg;
378
379 break_reg = kmalloc(2, GFP_KERNEL);
380 if (!break_reg)
381 return;
382
383 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
384 ch341_break_reg, 0, break_reg, 2);
385 if (r < 0) {
386 dev_err(&port->dev, "%s - USB control read error (%d)\n",
387 __func__, r);
388 goto out;
389 }
390 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
391 __func__, break_reg[0], break_reg[1]);
392 if (break_state != 0) {
393 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
394 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
395 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
396 } else {
397 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
398 break_reg[0] |= CH341_NBREAK_BITS_REG1;
399 break_reg[1] |= CH341_NBREAK_BITS_REG2;
400 }
401 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
402 __func__, break_reg[0], break_reg[1]);
403 reg_contents = get_unaligned_le16(break_reg);
404 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
405 ch341_break_reg, reg_contents);
406 if (r < 0)
407 dev_err(&port->dev, "%s - USB control write error (%d)\n",
408 __func__, r);
409out:
410 kfree(break_reg);
411}
412
413static int ch341_tiocmset(struct tty_struct *tty,
414 unsigned int set, unsigned int clear)
415{
416 struct usb_serial_port *port = tty->driver_data;
417 struct ch341_private *priv = usb_get_serial_port_data(port);
418 unsigned long flags;
419 u8 control;
420
421 spin_lock_irqsave(&priv->lock, flags);
422 if (set & TIOCM_RTS)
423 priv->line_control |= CH341_BIT_RTS;
424 if (set & TIOCM_DTR)
425 priv->line_control |= CH341_BIT_DTR;
426 if (clear & TIOCM_RTS)
427 priv->line_control &= ~CH341_BIT_RTS;
428 if (clear & TIOCM_DTR)
429 priv->line_control &= ~CH341_BIT_DTR;
430 control = priv->line_control;
431 spin_unlock_irqrestore(&priv->lock, flags);
432
433 return ch341_set_handshake(port->serial->dev, control);
434}
435
436static void ch341_update_line_status(struct usb_serial_port *port,
437 unsigned char *data, size_t len)
438{
439 struct ch341_private *priv = usb_get_serial_port_data(port);
440 struct tty_struct *tty;
441 unsigned long flags;
442 u8 status;
443 u8 delta;
444
445 if (len < 4)
446 return;
447
448 status = ~data[2] & CH341_BITS_MODEM_STAT;
449
450 spin_lock_irqsave(&priv->lock, flags);
451 delta = status ^ priv->line_status;
452 priv->line_status = status;
453 spin_unlock_irqrestore(&priv->lock, flags);
454
455 if (data[1] & CH341_MULT_STAT)
456 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
457
458 if (!delta)
459 return;
460
461 if (delta & CH341_BIT_CTS)
462 port->icount.cts++;
463 if (delta & CH341_BIT_DSR)
464 port->icount.dsr++;
465 if (delta & CH341_BIT_RI)
466 port->icount.rng++;
467 if (delta & CH341_BIT_DCD) {
468 port->icount.dcd++;
469 tty = tty_port_tty_get(&port->port);
470 if (tty) {
471 usb_serial_handle_dcd_change(port, tty,
472 status & CH341_BIT_DCD);
473 tty_kref_put(tty);
474 }
475 }
476
477 wake_up_interruptible(&port->port.delta_msr_wait);
478}
479
480static void ch341_read_int_callback(struct urb *urb)
481{
482 struct usb_serial_port *port = urb->context;
483 unsigned char *data = urb->transfer_buffer;
484 unsigned int len = urb->actual_length;
485 int status;
486
487 switch (urb->status) {
488 case 0:
489 /* success */
490 break;
491 case -ECONNRESET:
492 case -ENOENT:
493 case -ESHUTDOWN:
494 /* this urb is terminated, clean up */
495 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
496 __func__, urb->status);
497 return;
498 default:
499 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
500 __func__, urb->status);
501 goto exit;
502 }
503
504 usb_serial_debug_data(&port->dev, __func__, len, data);
505 ch341_update_line_status(port, data, len);
506exit:
507 status = usb_submit_urb(urb, GFP_ATOMIC);
508 if (status) {
509 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
510 __func__, status);
511 }
512}
513
514static int ch341_tiocmget(struct tty_struct *tty)
515{
516 struct usb_serial_port *port = tty->driver_data;
517 struct ch341_private *priv = usb_get_serial_port_data(port);
518 unsigned long flags;
519 u8 mcr;
520 u8 status;
521 unsigned int result;
522
523 spin_lock_irqsave(&priv->lock, flags);
524 mcr = priv->line_control;
525 status = priv->line_status;
526 spin_unlock_irqrestore(&priv->lock, flags);
527
528 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
529 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
530 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
531 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
532 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
533 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
534
535 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
536
537 return result;
538}
539
540static int ch341_reset_resume(struct usb_serial *serial)
541{
542 struct ch341_private *priv;
543
544 priv = usb_get_serial_port_data(serial->port[0]);
545
546 /* reconfigure ch341 serial port after bus-reset */
547 ch341_configure(serial->dev, priv);
548
549 return 0;
550}
551
552static struct usb_serial_driver ch341_device = {
553 .driver = {
554 .owner = THIS_MODULE,
555 .name = "ch341-uart",
556 },
557 .id_table = id_table,
558 .num_ports = 1,
559 .open = ch341_open,
560 .dtr_rts = ch341_dtr_rts,
561 .carrier_raised = ch341_carrier_raised,
562 .close = ch341_close,
563 .set_termios = ch341_set_termios,
564 .break_ctl = ch341_break_ctl,
565 .tiocmget = ch341_tiocmget,
566 .tiocmset = ch341_tiocmset,
567 .tiocmiwait = usb_serial_generic_tiocmiwait,
568 .read_int_callback = ch341_read_int_callback,
569 .port_probe = ch341_port_probe,
570 .port_remove = ch341_port_remove,
571 .reset_resume = ch341_reset_resume,
572};
573
574static struct usb_serial_driver * const serial_drivers[] = {
575 &ch341_device, NULL
576};
577
578module_usb_serial_driver(serial_drivers, id_table);
579
580MODULE_LICENSE("GPL");
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(0x4348, 0x5523) },
85 { USB_DEVICE(0x1a86, 0x7522) },
86 { USB_DEVICE(0x1a86, 0x7523) },
87 { USB_DEVICE(0x1a86, 0x5523) },
88 { },
89};
90MODULE_DEVICE_TABLE(usb, id_table);
91
92struct ch341_private {
93 spinlock_t lock; /* access lock */
94 unsigned baud_rate; /* set baud rate */
95 u8 mcr;
96 u8 msr;
97 u8 lcr;
98 unsigned long quirks;
99 unsigned long break_end;
100};
101
102static void ch341_set_termios(struct tty_struct *tty,
103 struct usb_serial_port *port,
104 struct ktermios *old_termios);
105
106static int ch341_control_out(struct usb_device *dev, u8 request,
107 u16 value, u16 index)
108{
109 int r;
110
111 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__,
112 request, value, index);
113
114 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
115 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
116 value, index, NULL, 0, DEFAULT_TIMEOUT);
117 if (r < 0)
118 dev_err(&dev->dev, "failed to send control message: %d\n", r);
119
120 return r;
121}
122
123static int ch341_control_in(struct usb_device *dev,
124 u8 request, u16 value, u16 index,
125 char *buf, unsigned bufsize)
126{
127 int r;
128
129 dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__,
130 request, value, index, bufsize);
131
132 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
133 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
134 value, index, buf, bufsize, DEFAULT_TIMEOUT);
135 if (r < (int)bufsize) {
136 if (r >= 0) {
137 dev_err(&dev->dev,
138 "short control message received (%d < %u)\n",
139 r, bufsize);
140 r = -EIO;
141 }
142
143 dev_err(&dev->dev, "failed to receive control message: %d\n",
144 r);
145 return r;
146 }
147
148 return 0;
149}
150
151#define CH341_CLKRATE 48000000
152#define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact)))
153#define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512))
154
155static const speed_t ch341_min_rates[] = {
156 CH341_MIN_RATE(0),
157 CH341_MIN_RATE(1),
158 CH341_MIN_RATE(2),
159 CH341_MIN_RATE(3),
160};
161
162/* Supported range is 46 to 3000000 bps. */
163#define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256)
164#define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2))
165
166/*
167 * The device line speed is given by the following equation:
168 *
169 * baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where
170 *
171 * 0 <= ps <= 3,
172 * 0 <= fact <= 1,
173 * 2 <= div <= 256 if fact = 0, or
174 * 9 <= div <= 256 if fact = 1
175 */
176static int ch341_get_divisor(struct ch341_private *priv, speed_t speed)
177{
178 unsigned int fact, div, clk_div;
179 bool force_fact0 = false;
180 int ps;
181
182 /*
183 * Clamp to supported range, this makes the (ps < 0) and (div < 2)
184 * sanity checks below redundant.
185 */
186 speed = clamp_val(speed, CH341_MIN_BPS, CH341_MAX_BPS);
187
188 /*
189 * Start with highest possible base clock (fact = 1) that will give a
190 * divisor strictly less than 512.
191 */
192 fact = 1;
193 for (ps = 3; ps >= 0; ps--) {
194 if (speed > ch341_min_rates[ps])
195 break;
196 }
197
198 if (ps < 0)
199 return -EINVAL;
200
201 /* Determine corresponding divisor, rounding down. */
202 clk_div = CH341_CLK_DIV(ps, fact);
203 div = CH341_CLKRATE / (clk_div * speed);
204
205 /* Some devices require a lower base clock if ps < 3. */
206 if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER))
207 force_fact0 = true;
208
209 /* Halve base clock (fact = 0) if required. */
210 if (div < 9 || div > 255 || force_fact0) {
211 div /= 2;
212 clk_div *= 2;
213 fact = 0;
214 }
215
216 if (div < 2)
217 return -EINVAL;
218
219 /*
220 * Pick next divisor if resulting rate is closer to the requested one,
221 * scale up to avoid rounding errors on low rates.
222 */
223 if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >=
224 16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1)))
225 div++;
226
227 /*
228 * Prefer lower base clock (fact = 0) if even divisor.
229 *
230 * Note that this makes the receiver more tolerant to errors.
231 */
232 if (fact == 1 && div % 2 == 0) {
233 div /= 2;
234 fact = 0;
235 }
236
237 return (0x100 - div) << 8 | fact << 2 | ps;
238}
239
240static int ch341_set_baudrate_lcr(struct usb_device *dev,
241 struct ch341_private *priv,
242 speed_t baud_rate, u8 lcr)
243{
244 int val;
245 int r;
246
247 if (!baud_rate)
248 return -EINVAL;
249
250 val = ch341_get_divisor(priv, baud_rate);
251 if (val < 0)
252 return -EINVAL;
253
254 /*
255 * CH341A buffers data until a full endpoint-size packet (32 bytes)
256 * has been received unless bit 7 is set.
257 */
258 val |= BIT(7);
259
260 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
261 CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER,
262 val);
263 if (r)
264 return r;
265
266 /*
267 * Chip versions before version 0x30 as read using
268 * CH341_REQ_READ_VERSION used separate registers for line control
269 * (stop bits, parity and word length). Version 0x30 and above use
270 * CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero.
271 */
272 r = ch341_control_out(dev, CH341_REQ_WRITE_REG,
273 CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr);
274 if (r)
275 return r;
276
277 return r;
278}
279
280static int ch341_set_handshake(struct usb_device *dev, u8 control)
281{
282 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
283}
284
285static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
286{
287 const unsigned int size = 2;
288 char *buffer;
289 int r;
290 unsigned long flags;
291
292 buffer = kmalloc(size, GFP_KERNEL);
293 if (!buffer)
294 return -ENOMEM;
295
296 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
297 if (r < 0)
298 goto out;
299
300 spin_lock_irqsave(&priv->lock, flags);
301 priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT;
302 spin_unlock_irqrestore(&priv->lock, flags);
303
304out: kfree(buffer);
305 return r;
306}
307
308/* -------------------------------------------------------------------------- */
309
310static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
311{
312 const unsigned int size = 2;
313 char *buffer;
314 int r;
315
316 buffer = kmalloc(size, GFP_KERNEL);
317 if (!buffer)
318 return -ENOMEM;
319
320 /* expect two bytes 0x27 0x00 */
321 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
322 if (r < 0)
323 goto out;
324 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
325
326 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
327 if (r < 0)
328 goto out;
329
330 r = ch341_set_baudrate_lcr(dev, priv, priv->baud_rate, priv->lcr);
331 if (r < 0)
332 goto out;
333
334 r = ch341_set_handshake(dev, priv->mcr);
335
336out: kfree(buffer);
337 return r;
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 char *buffer;
347 int r;
348
349 buffer = kmalloc(size, GFP_KERNEL);
350 if (!buffer)
351 return -ENOMEM;
352
353 /*
354 * A subset of CH34x devices does not support all features. The
355 * prescaler is limited and there is no support for sending a RS232
356 * break condition. A read failure when trying to set up the latter is
357 * used to detect these devices.
358 */
359 r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG,
360 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
361 CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT);
362 if (r == -EPIPE) {
363 dev_info(&port->dev, "break control not supported, using simulated break\n");
364 quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK;
365 r = 0;
366 goto out;
367 }
368
369 if (r != size) {
370 if (r >= 0)
371 r = -EIO;
372 dev_err(&port->dev, "failed to read break control: %d\n", r);
373 goto out;
374 }
375
376 r = 0;
377out:
378 kfree(buffer);
379
380 if (quirks) {
381 dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks);
382 priv->quirks |= quirks;
383 }
384
385 return r;
386}
387
388static int ch341_port_probe(struct usb_serial_port *port)
389{
390 struct ch341_private *priv;
391 int r;
392
393 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
394 if (!priv)
395 return -ENOMEM;
396
397 spin_lock_init(&priv->lock);
398 priv->baud_rate = DEFAULT_BAUD_RATE;
399 /*
400 * Some CH340 devices appear unable to change the initial LCR
401 * settings, so set a sane 8N1 default.
402 */
403 priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
404
405 r = ch341_configure(port->serial->dev, priv);
406 if (r < 0)
407 goto error;
408
409 usb_set_serial_port_data(port, priv);
410
411 r = ch341_detect_quirks(port);
412 if (r < 0)
413 goto error;
414
415 return 0;
416
417error: kfree(priv);
418 return r;
419}
420
421static int ch341_port_remove(struct usb_serial_port *port)
422{
423 struct ch341_private *priv;
424
425 priv = usb_get_serial_port_data(port);
426 kfree(priv);
427
428 return 0;
429}
430
431static int ch341_carrier_raised(struct usb_serial_port *port)
432{
433 struct ch341_private *priv = usb_get_serial_port_data(port);
434 if (priv->msr & CH341_BIT_DCD)
435 return 1;
436 return 0;
437}
438
439static void ch341_dtr_rts(struct usb_serial_port *port, int on)
440{
441 struct ch341_private *priv = usb_get_serial_port_data(port);
442 unsigned long flags;
443
444 /* drop DTR and RTS */
445 spin_lock_irqsave(&priv->lock, flags);
446 if (on)
447 priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR;
448 else
449 priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
450 spin_unlock_irqrestore(&priv->lock, flags);
451 ch341_set_handshake(port->serial->dev, priv->mcr);
452}
453
454static void ch341_close(struct usb_serial_port *port)
455{
456 usb_serial_generic_close(port);
457 usb_kill_urb(port->interrupt_in_urb);
458}
459
460
461/* open this device, set default parameters */
462static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
463{
464 struct ch341_private *priv = usb_get_serial_port_data(port);
465 int r;
466
467 if (tty)
468 ch341_set_termios(tty, port, NULL);
469
470 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
471 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
472 if (r) {
473 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
474 __func__, r);
475 return r;
476 }
477
478 r = ch341_get_status(port->serial->dev, priv);
479 if (r < 0) {
480 dev_err(&port->dev, "failed to read modem status: %d\n", r);
481 goto err_kill_interrupt_urb;
482 }
483
484 r = usb_serial_generic_open(tty, port);
485 if (r)
486 goto err_kill_interrupt_urb;
487
488 return 0;
489
490err_kill_interrupt_urb:
491 usb_kill_urb(port->interrupt_in_urb);
492
493 return r;
494}
495
496/* Old_termios contains the original termios settings and
497 * tty->termios contains the new setting to be used.
498 */
499static void ch341_set_termios(struct tty_struct *tty,
500 struct usb_serial_port *port, struct ktermios *old_termios)
501{
502 struct ch341_private *priv = usb_get_serial_port_data(port);
503 unsigned baud_rate;
504 unsigned long flags;
505 u8 lcr;
506 int r;
507
508 /* redundant changes may cause the chip to lose bytes */
509 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
510 return;
511
512 baud_rate = tty_get_baud_rate(tty);
513
514 lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
515
516 switch (C_CSIZE(tty)) {
517 case CS5:
518 lcr |= CH341_LCR_CS5;
519 break;
520 case CS6:
521 lcr |= CH341_LCR_CS6;
522 break;
523 case CS7:
524 lcr |= CH341_LCR_CS7;
525 break;
526 case CS8:
527 lcr |= CH341_LCR_CS8;
528 break;
529 }
530
531 if (C_PARENB(tty)) {
532 lcr |= CH341_LCR_ENABLE_PAR;
533 if (C_PARODD(tty) == 0)
534 lcr |= CH341_LCR_PAR_EVEN;
535 if (C_CMSPAR(tty))
536 lcr |= CH341_LCR_MARK_SPACE;
537 }
538
539 if (C_CSTOPB(tty))
540 lcr |= CH341_LCR_STOP_BITS_2;
541
542 if (baud_rate) {
543 priv->baud_rate = baud_rate;
544
545 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
546 priv->baud_rate, lcr);
547 if (r < 0 && old_termios) {
548 priv->baud_rate = tty_termios_baud_rate(old_termios);
549 tty_termios_copy_hw(&tty->termios, old_termios);
550 } else if (r == 0) {
551 priv->lcr = lcr;
552 }
553 }
554
555 spin_lock_irqsave(&priv->lock, flags);
556 if (C_BAUD(tty) == B0)
557 priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
558 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
559 priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS);
560 spin_unlock_irqrestore(&priv->lock, flags);
561
562 ch341_set_handshake(port->serial->dev, priv->mcr);
563}
564
565/*
566 * A subset of all CH34x devices don't support a real break condition and
567 * reading CH341_REG_BREAK fails (see also ch341_detect_quirks). This function
568 * simulates a break condition by lowering the baud rate to the minimum
569 * supported by the hardware upon enabling the break condition and sending
570 * a NUL byte.
571 *
572 * Incoming data is corrupted while the break condition is being simulated.
573 *
574 * Normally the duration of the break condition can be controlled individually
575 * by userspace using TIOCSBRK and TIOCCBRK or by passing an argument to
576 * TCSBRKP. Due to how the simulation is implemented the duration can't be
577 * controlled. The duration is always about (1s / 46bd * 9bit) = 196ms.
578 */
579static void ch341_simulate_break(struct tty_struct *tty, int break_state)
580{
581 struct usb_serial_port *port = tty->driver_data;
582 struct ch341_private *priv = usb_get_serial_port_data(port);
583 unsigned long now, delay;
584 int r;
585
586 if (break_state != 0) {
587 dev_dbg(&port->dev, "enter break state requested\n");
588
589 r = ch341_set_baudrate_lcr(port->serial->dev, priv,
590 CH341_MIN_BPS,
591 CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8);
592 if (r < 0) {
593 dev_err(&port->dev,
594 "failed to change baud rate to %u: %d\n",
595 CH341_MIN_BPS, r);
596 goto restore;
597 }
598
599 r = tty_put_char(tty, '\0');
600 if (r < 0) {
601 dev_err(&port->dev,
602 "failed to write NUL byte for simulated break condition: %d\n",
603 r);
604 goto restore;
605 }
606
607 /*
608 * Compute expected transmission duration including safety
609 * margin. The original baud rate is only restored after the
610 * computed point in time.
611 *
612 * 11 bits = 1 start, 8 data, 1 stop, 1 margin
613 */
614 priv->break_end = jiffies + (11 * HZ / CH341_MIN_BPS);
615
616 return;
617 }
618
619 dev_dbg(&port->dev, "leave break state requested\n");
620
621 now = jiffies;
622
623 if (time_before(now, priv->break_end)) {
624 /* Wait until NUL byte is written */
625 delay = priv->break_end - now;
626 dev_dbg(&port->dev,
627 "wait %d ms while transmitting NUL byte at %u baud\n",
628 jiffies_to_msecs(delay), CH341_MIN_BPS);
629 schedule_timeout_interruptible(delay);
630 }
631
632restore:
633 /* Restore original baud rate */
634 r = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate,
635 priv->lcr);
636 if (r < 0)
637 dev_err(&port->dev,
638 "restoring original baud rate of %u failed: %d\n",
639 priv->baud_rate, r);
640}
641
642static void ch341_break_ctl(struct tty_struct *tty, int break_state)
643{
644 const uint16_t ch341_break_reg =
645 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
646 struct usb_serial_port *port = tty->driver_data;
647 struct ch341_private *priv = usb_get_serial_port_data(port);
648 int r;
649 uint16_t reg_contents;
650 uint8_t *break_reg;
651
652 if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK) {
653 ch341_simulate_break(tty, break_state);
654 return;
655 }
656
657 break_reg = kmalloc(2, GFP_KERNEL);
658 if (!break_reg)
659 return;
660
661 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
662 ch341_break_reg, 0, break_reg, 2);
663 if (r < 0) {
664 dev_err(&port->dev, "%s - USB control read error (%d)\n",
665 __func__, r);
666 goto out;
667 }
668 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
669 __func__, break_reg[0], break_reg[1]);
670 if (break_state != 0) {
671 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
672 break_reg[0] &= ~CH341_NBREAK_BITS;
673 break_reg[1] &= ~CH341_LCR_ENABLE_TX;
674 } else {
675 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
676 break_reg[0] |= CH341_NBREAK_BITS;
677 break_reg[1] |= CH341_LCR_ENABLE_TX;
678 }
679 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
680 __func__, break_reg[0], break_reg[1]);
681 reg_contents = get_unaligned_le16(break_reg);
682 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
683 ch341_break_reg, reg_contents);
684 if (r < 0)
685 dev_err(&port->dev, "%s - USB control write error (%d)\n",
686 __func__, r);
687out:
688 kfree(break_reg);
689}
690
691static int ch341_tiocmset(struct tty_struct *tty,
692 unsigned int set, unsigned int clear)
693{
694 struct usb_serial_port *port = tty->driver_data;
695 struct ch341_private *priv = usb_get_serial_port_data(port);
696 unsigned long flags;
697 u8 control;
698
699 spin_lock_irqsave(&priv->lock, flags);
700 if (set & TIOCM_RTS)
701 priv->mcr |= CH341_BIT_RTS;
702 if (set & TIOCM_DTR)
703 priv->mcr |= CH341_BIT_DTR;
704 if (clear & TIOCM_RTS)
705 priv->mcr &= ~CH341_BIT_RTS;
706 if (clear & TIOCM_DTR)
707 priv->mcr &= ~CH341_BIT_DTR;
708 control = priv->mcr;
709 spin_unlock_irqrestore(&priv->lock, flags);
710
711 return ch341_set_handshake(port->serial->dev, control);
712}
713
714static void ch341_update_status(struct usb_serial_port *port,
715 unsigned char *data, size_t len)
716{
717 struct ch341_private *priv = usb_get_serial_port_data(port);
718 struct tty_struct *tty;
719 unsigned long flags;
720 u8 status;
721 u8 delta;
722
723 if (len < 4)
724 return;
725
726 status = ~data[2] & CH341_BITS_MODEM_STAT;
727
728 spin_lock_irqsave(&priv->lock, flags);
729 delta = status ^ priv->msr;
730 priv->msr = status;
731 spin_unlock_irqrestore(&priv->lock, flags);
732
733 if (data[1] & CH341_MULT_STAT)
734 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
735
736 if (!delta)
737 return;
738
739 if (delta & CH341_BIT_CTS)
740 port->icount.cts++;
741 if (delta & CH341_BIT_DSR)
742 port->icount.dsr++;
743 if (delta & CH341_BIT_RI)
744 port->icount.rng++;
745 if (delta & CH341_BIT_DCD) {
746 port->icount.dcd++;
747 tty = tty_port_tty_get(&port->port);
748 if (tty) {
749 usb_serial_handle_dcd_change(port, tty,
750 status & CH341_BIT_DCD);
751 tty_kref_put(tty);
752 }
753 }
754
755 wake_up_interruptible(&port->port.delta_msr_wait);
756}
757
758static void ch341_read_int_callback(struct urb *urb)
759{
760 struct usb_serial_port *port = urb->context;
761 unsigned char *data = urb->transfer_buffer;
762 unsigned int len = urb->actual_length;
763 int status;
764
765 switch (urb->status) {
766 case 0:
767 /* success */
768 break;
769 case -ECONNRESET:
770 case -ENOENT:
771 case -ESHUTDOWN:
772 /* this urb is terminated, clean up */
773 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
774 __func__, urb->status);
775 return;
776 default:
777 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
778 __func__, urb->status);
779 goto exit;
780 }
781
782 usb_serial_debug_data(&port->dev, __func__, len, data);
783 ch341_update_status(port, data, len);
784exit:
785 status = usb_submit_urb(urb, GFP_ATOMIC);
786 if (status) {
787 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
788 __func__, status);
789 }
790}
791
792static int ch341_tiocmget(struct tty_struct *tty)
793{
794 struct usb_serial_port *port = tty->driver_data;
795 struct ch341_private *priv = usb_get_serial_port_data(port);
796 unsigned long flags;
797 u8 mcr;
798 u8 status;
799 unsigned int result;
800
801 spin_lock_irqsave(&priv->lock, flags);
802 mcr = priv->mcr;
803 status = priv->msr;
804 spin_unlock_irqrestore(&priv->lock, flags);
805
806 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
807 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
808 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
809 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
810 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
811 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
812
813 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
814
815 return result;
816}
817
818static int ch341_reset_resume(struct usb_serial *serial)
819{
820 struct usb_serial_port *port = serial->port[0];
821 struct ch341_private *priv;
822 int ret;
823
824 priv = usb_get_serial_port_data(port);
825 if (!priv)
826 return 0;
827
828 /* reconfigure ch341 serial port after bus-reset */
829 ch341_configure(serial->dev, priv);
830
831 if (tty_port_initialized(&port->port)) {
832 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
833 if (ret) {
834 dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
835 ret);
836 return ret;
837 }
838
839 ret = ch341_get_status(port->serial->dev, priv);
840 if (ret < 0) {
841 dev_err(&port->dev, "failed to read modem status: %d\n",
842 ret);
843 }
844 }
845
846 return usb_serial_generic_resume(serial);
847}
848
849static struct usb_serial_driver ch341_device = {
850 .driver = {
851 .owner = THIS_MODULE,
852 .name = "ch341-uart",
853 },
854 .id_table = id_table,
855 .num_ports = 1,
856 .open = ch341_open,
857 .dtr_rts = ch341_dtr_rts,
858 .carrier_raised = ch341_carrier_raised,
859 .close = ch341_close,
860 .set_termios = ch341_set_termios,
861 .break_ctl = ch341_break_ctl,
862 .tiocmget = ch341_tiocmget,
863 .tiocmset = ch341_tiocmset,
864 .tiocmiwait = usb_serial_generic_tiocmiwait,
865 .read_int_callback = ch341_read_int_callback,
866 .port_probe = ch341_port_probe,
867 .port_remove = ch341_port_remove,
868 .reset_resume = ch341_reset_resume,
869};
870
871static struct usb_serial_driver * const serial_drivers[] = {
872 &ch341_device, NULL
873};
874
875module_usb_serial_driver(serial_drivers, id_table);
876
877MODULE_LICENSE("GPL v2");