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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/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 int 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 dbg("ch341_set_baudrate(%d)", priv->baud_rate);
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 dbg("ch341_set_handshake(0x%02x)", control);
157 return ch341_control_out(dev, 0xa4, ~control, 0);
158}
159
160static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
161{
162 char *buffer;
163 int r;
164 const unsigned size = 8;
165 unsigned long flags;
166
167 dbg("ch341_get_status()");
168
169 buffer = kmalloc(size, GFP_KERNEL);
170 if (!buffer)
171 return -ENOMEM;
172
173 r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
174 if (r < 0)
175 goto out;
176
177 /* setup the private status if available */
178 if (r == 2) {
179 r = 0;
180 spin_lock_irqsave(&priv->lock, flags);
181 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
182 priv->multi_status_change = 0;
183 spin_unlock_irqrestore(&priv->lock, flags);
184 } else
185 r = -EPROTO;
186
187out: kfree(buffer);
188 return r;
189}
190
191/* -------------------------------------------------------------------------- */
192
193static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
194{
195 char *buffer;
196 int r;
197 const unsigned size = 8;
198
199 dbg("ch341_configure()");
200
201 buffer = kmalloc(size, GFP_KERNEL);
202 if (!buffer)
203 return -ENOMEM;
204
205 /* expect two bytes 0x27 0x00 */
206 r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
207 if (r < 0)
208 goto out;
209
210 r = ch341_control_out(dev, 0xa1, 0, 0);
211 if (r < 0)
212 goto out;
213
214 r = ch341_set_baudrate(dev, priv);
215 if (r < 0)
216 goto out;
217
218 /* expect two bytes 0x56 0x00 */
219 r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
220 if (r < 0)
221 goto out;
222
223 r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
224 if (r < 0)
225 goto out;
226
227 /* expect 0xff 0xee */
228 r = ch341_get_status(dev, priv);
229 if (r < 0)
230 goto out;
231
232 r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
233 if (r < 0)
234 goto out;
235
236 r = ch341_set_baudrate(dev, priv);
237 if (r < 0)
238 goto out;
239
240 r = ch341_set_handshake(dev, priv->line_control);
241 if (r < 0)
242 goto out;
243
244 /* expect 0x9f 0xee */
245 r = ch341_get_status(dev, priv);
246
247out: kfree(buffer);
248 return r;
249}
250
251/* allocate private data */
252static int ch341_attach(struct usb_serial *serial)
253{
254 struct ch341_private *priv;
255 int r;
256
257 dbg("ch341_attach()");
258
259 /* private data */
260 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
261 if (!priv)
262 return -ENOMEM;
263
264 spin_lock_init(&priv->lock);
265 init_waitqueue_head(&priv->delta_msr_wait);
266 priv->baud_rate = DEFAULT_BAUD_RATE;
267 priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
268
269 r = ch341_configure(serial->dev, priv);
270 if (r < 0)
271 goto error;
272
273 usb_set_serial_port_data(serial->port[0], priv);
274 return 0;
275
276error: kfree(priv);
277 return r;
278}
279
280static int ch341_carrier_raised(struct usb_serial_port *port)
281{
282 struct ch341_private *priv = usb_get_serial_port_data(port);
283 if (priv->line_status & CH341_BIT_DCD)
284 return 1;
285 return 0;
286}
287
288static void ch341_dtr_rts(struct usb_serial_port *port, int on)
289{
290 struct ch341_private *priv = usb_get_serial_port_data(port);
291 unsigned long flags;
292
293 dbg("%s - port %d", __func__, port->number);
294 /* drop DTR and RTS */
295 spin_lock_irqsave(&priv->lock, flags);
296 if (on)
297 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
298 else
299 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
300 spin_unlock_irqrestore(&priv->lock, flags);
301 ch341_set_handshake(port->serial->dev, priv->line_control);
302 wake_up_interruptible(&priv->delta_msr_wait);
303}
304
305static void ch341_close(struct usb_serial_port *port)
306{
307 dbg("%s - port %d", __func__, port->number);
308
309 usb_serial_generic_close(port);
310 usb_kill_urb(port->interrupt_in_urb);
311}
312
313
314/* open this device, set default parameters */
315static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
316{
317 struct usb_serial *serial = port->serial;
318 struct ch341_private *priv = usb_get_serial_port_data(serial->port[0]);
319 int r;
320
321 dbg("ch341_open()");
322
323 priv->baud_rate = DEFAULT_BAUD_RATE;
324
325 r = ch341_configure(serial->dev, priv);
326 if (r)
327 goto out;
328
329 r = ch341_set_handshake(serial->dev, priv->line_control);
330 if (r)
331 goto out;
332
333 r = ch341_set_baudrate(serial->dev, priv);
334 if (r)
335 goto out;
336
337 dbg("%s - submitting interrupt urb", __func__);
338 port->interrupt_in_urb->dev = serial->dev;
339 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
340 if (r) {
341 dev_err(&port->dev, "%s - failed submitting interrupt urb,"
342 " error %d\n", __func__, r);
343 ch341_close(port);
344 return -EPROTO;
345 }
346
347 r = usb_serial_generic_open(tty, port);
348
349out: return r;
350}
351
352/* Old_termios contains the original termios settings and
353 * tty->termios contains the new setting to be used.
354 */
355static void ch341_set_termios(struct tty_struct *tty,
356 struct usb_serial_port *port, struct ktermios *old_termios)
357{
358 struct ch341_private *priv = usb_get_serial_port_data(port);
359 unsigned baud_rate;
360 unsigned long flags;
361
362 dbg("ch341_set_termios()");
363
364 baud_rate = tty_get_baud_rate(tty);
365
366 priv->baud_rate = baud_rate;
367
368 if (baud_rate) {
369 spin_lock_irqsave(&priv->lock, flags);
370 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
371 spin_unlock_irqrestore(&priv->lock, flags);
372 ch341_set_baudrate(port->serial->dev, priv);
373 } else {
374 spin_lock_irqsave(&priv->lock, flags);
375 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
376 spin_unlock_irqrestore(&priv->lock, flags);
377 }
378
379 ch341_set_handshake(port->serial->dev, priv->line_control);
380
381 /* Unimplemented:
382 * (cflag & CSIZE) : data bits [5, 8]
383 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
384 * (cflag & CSTOPB) : stop bits [1, 2]
385 */
386}
387
388static void ch341_break_ctl(struct tty_struct *tty, int break_state)
389{
390 const uint16_t ch341_break_reg =
391 CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
392 struct usb_serial_port *port = tty->driver_data;
393 int r;
394 uint16_t reg_contents;
395 uint8_t *break_reg;
396
397 dbg("%s()", __func__);
398
399 break_reg = kmalloc(2, GFP_KERNEL);
400 if (!break_reg) {
401 dev_err(&port->dev, "%s - kmalloc failed\n", __func__);
402 return;
403 }
404
405 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
406 ch341_break_reg, 0, break_reg, 2);
407 if (r < 0) {
408 dev_err(&port->dev, "%s - USB control read error (%d)\n",
409 __func__, r);
410 goto out;
411 }
412 dbg("%s - initial ch341 break register contents - reg1: %x, reg2: %x",
413 __func__, break_reg[0], break_reg[1]);
414 if (break_state != 0) {
415 dbg("%s - Enter break state requested", __func__);
416 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
417 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
418 } else {
419 dbg("%s - Leave break state requested", __func__);
420 break_reg[0] |= CH341_NBREAK_BITS_REG1;
421 break_reg[1] |= CH341_NBREAK_BITS_REG2;
422 }
423 dbg("%s - New ch341 break register contents - reg1: %x, reg2: %x",
424 __func__, break_reg[0], break_reg[1]);
425 reg_contents = get_unaligned_le16(break_reg);
426 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
427 ch341_break_reg, reg_contents);
428 if (r < 0)
429 dev_err(&port->dev, "%s - USB control write error (%d)\n",
430 __func__, r);
431out:
432 kfree(break_reg);
433}
434
435static int ch341_tiocmset(struct tty_struct *tty,
436 unsigned int set, unsigned int clear)
437{
438 struct usb_serial_port *port = tty->driver_data;
439 struct ch341_private *priv = usb_get_serial_port_data(port);
440 unsigned long flags;
441 u8 control;
442
443 spin_lock_irqsave(&priv->lock, flags);
444 if (set & TIOCM_RTS)
445 priv->line_control |= CH341_BIT_RTS;
446 if (set & TIOCM_DTR)
447 priv->line_control |= CH341_BIT_DTR;
448 if (clear & TIOCM_RTS)
449 priv->line_control &= ~CH341_BIT_RTS;
450 if (clear & TIOCM_DTR)
451 priv->line_control &= ~CH341_BIT_DTR;
452 control = priv->line_control;
453 spin_unlock_irqrestore(&priv->lock, flags);
454
455 return ch341_set_handshake(port->serial->dev, control);
456}
457
458static void ch341_read_int_callback(struct urb *urb)
459{
460 struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
461 unsigned char *data = urb->transfer_buffer;
462 unsigned int actual_length = urb->actual_length;
463 int status;
464
465 dbg("%s (%d)", __func__, port->number);
466
467 switch (urb->status) {
468 case 0:
469 /* success */
470 break;
471 case -ECONNRESET:
472 case -ENOENT:
473 case -ESHUTDOWN:
474 /* this urb is terminated, clean up */
475 dbg("%s - urb shutting down with status: %d", __func__,
476 urb->status);
477 return;
478 default:
479 dbg("%s - nonzero urb status received: %d", __func__,
480 urb->status);
481 goto exit;
482 }
483
484 usb_serial_debug_data(debug, &port->dev, __func__,
485 urb->actual_length, urb->transfer_buffer);
486
487 if (actual_length >= 4) {
488 struct ch341_private *priv = usb_get_serial_port_data(port);
489 unsigned long flags;
490 u8 prev_line_status = priv->line_status;
491
492 spin_lock_irqsave(&priv->lock, flags);
493 priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
494 if ((data[1] & CH341_MULT_STAT))
495 priv->multi_status_change = 1;
496 spin_unlock_irqrestore(&priv->lock, flags);
497
498 if ((priv->line_status ^ prev_line_status) & CH341_BIT_DCD) {
499 struct tty_struct *tty = tty_port_tty_get(&port->port);
500 if (tty)
501 usb_serial_handle_dcd_change(port, tty,
502 priv->line_status & CH341_BIT_DCD);
503 tty_kref_put(tty);
504 }
505
506 wake_up_interruptible(&priv->delta_msr_wait);
507 }
508
509exit:
510 status = usb_submit_urb(urb, GFP_ATOMIC);
511 if (status)
512 dev_err(&urb->dev->dev,
513 "%s - usb_submit_urb failed with result %d\n",
514 __func__, status);
515}
516
517static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
518{
519 struct ch341_private *priv = usb_get_serial_port_data(port);
520 unsigned long flags;
521 u8 prevstatus;
522 u8 status;
523 u8 changed;
524 u8 multi_change = 0;
525
526 spin_lock_irqsave(&priv->lock, flags);
527 prevstatus = priv->line_status;
528 priv->multi_status_change = 0;
529 spin_unlock_irqrestore(&priv->lock, flags);
530
531 while (!multi_change) {
532 interruptible_sleep_on(&priv->delta_msr_wait);
533 /* see if a signal did it */
534 if (signal_pending(current))
535 return -ERESTARTSYS;
536
537 spin_lock_irqsave(&priv->lock, flags);
538 status = priv->line_status;
539 multi_change = priv->multi_status_change;
540 spin_unlock_irqrestore(&priv->lock, flags);
541
542 changed = prevstatus ^ status;
543
544 if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
545 ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
546 ((arg & TIOCM_CD) && (changed & CH341_BIT_DCD)) ||
547 ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
548 return 0;
549 }
550 prevstatus = status;
551 }
552
553 return 0;
554}
555
556static int ch341_ioctl(struct tty_struct *tty,
557 unsigned int cmd, unsigned long arg)
558{
559 struct usb_serial_port *port = tty->driver_data;
560 dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
561
562 switch (cmd) {
563 case TIOCMIWAIT:
564 dbg("%s (%d) TIOCMIWAIT", __func__, port->number);
565 return wait_modem_info(port, arg);
566
567 default:
568 dbg("%s not supported = 0x%04x", __func__, cmd);
569 break;
570 }
571
572 return -ENOIOCTLCMD;
573}
574
575static int ch341_tiocmget(struct tty_struct *tty)
576{
577 struct usb_serial_port *port = tty->driver_data;
578 struct ch341_private *priv = usb_get_serial_port_data(port);
579 unsigned long flags;
580 u8 mcr;
581 u8 status;
582 unsigned int result;
583
584 dbg("%s (%d)", __func__, port->number);
585
586 spin_lock_irqsave(&priv->lock, flags);
587 mcr = priv->line_control;
588 status = priv->line_status;
589 spin_unlock_irqrestore(&priv->lock, flags);
590
591 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
592 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
593 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
594 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
595 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
596 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
597
598 dbg("%s - result = %x", __func__, result);
599
600 return result;
601}
602
603
604static int ch341_reset_resume(struct usb_interface *intf)
605{
606 struct usb_device *dev = interface_to_usbdev(intf);
607 struct usb_serial *serial = NULL;
608 struct ch341_private *priv;
609
610 serial = usb_get_intfdata(intf);
611 priv = usb_get_serial_port_data(serial->port[0]);
612
613 /*reconfigure ch341 serial port after bus-reset*/
614 ch341_configure(dev, priv);
615
616 usb_serial_resume(intf);
617
618 return 0;
619}
620
621static struct usb_driver ch341_driver = {
622 .name = "ch341",
623 .probe = usb_serial_probe,
624 .disconnect = usb_serial_disconnect,
625 .suspend = usb_serial_suspend,
626 .resume = usb_serial_resume,
627 .reset_resume = ch341_reset_resume,
628 .id_table = id_table,
629 .no_dynamic_id = 1,
630 .supports_autosuspend = 1,
631};
632
633static struct usb_serial_driver ch341_device = {
634 .driver = {
635 .owner = THIS_MODULE,
636 .name = "ch341-uart",
637 },
638 .id_table = id_table,
639 .usb_driver = &ch341_driver,
640 .num_ports = 1,
641 .open = ch341_open,
642 .dtr_rts = ch341_dtr_rts,
643 .carrier_raised = ch341_carrier_raised,
644 .close = ch341_close,
645 .ioctl = ch341_ioctl,
646 .set_termios = ch341_set_termios,
647 .break_ctl = ch341_break_ctl,
648 .tiocmget = ch341_tiocmget,
649 .tiocmset = ch341_tiocmset,
650 .read_int_callback = ch341_read_int_callback,
651 .attach = ch341_attach,
652};
653
654static int __init ch341_init(void)
655{
656 int retval;
657
658 retval = usb_serial_register(&ch341_device);
659 if (retval)
660 return retval;
661 retval = usb_register(&ch341_driver);
662 if (retval)
663 usb_serial_deregister(&ch341_device);
664 return retval;
665}
666
667static void __exit ch341_exit(void)
668{
669 usb_deregister(&ch341_driver);
670 usb_serial_deregister(&ch341_device);
671}
672
673module_init(ch341_init);
674module_exit(ch341_exit);
675MODULE_LICENSE("GPL");
676
677module_param(debug, bool, S_IRUGO | S_IWUSR);
678MODULE_PARM_DESC(debug, "Debug enabled or not");
679
680/* EOF ch341.c */
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 int ch341_control_out(struct usb_device *dev, u8 request,
88 u16 value, u16 index)
89{
90 int r;
91
92 dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
93 USB_DIR_OUT|0x40, (int)request, (int)value, (int)index);
94
95 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
96 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
97 value, index, NULL, 0, DEFAULT_TIMEOUT);
98
99 return r;
100}
101
102static int ch341_control_in(struct usb_device *dev,
103 u8 request, u16 value, u16 index,
104 char *buf, unsigned bufsize)
105{
106 int r;
107
108 dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
109 USB_DIR_IN|0x40, (int)request, (int)value, (int)index, buf,
110 (int)bufsize);
111
112 r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request,
113 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN,
114 value, index, buf, bufsize, DEFAULT_TIMEOUT);
115 return r;
116}
117
118static int ch341_set_baudrate(struct usb_device *dev,
119 struct ch341_private *priv)
120{
121 short a, b;
122 int r;
123 unsigned long factor;
124 short divisor;
125
126 if (!priv->baud_rate)
127 return -EINVAL;
128 factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
129 divisor = CH341_BAUDBASE_DIVMAX;
130
131 while ((factor > 0xfff0) && divisor) {
132 factor >>= 3;
133 divisor--;
134 }
135
136 if (factor > 0xfff0)
137 return -EINVAL;
138
139 factor = 0x10000 - factor;
140 a = (factor & 0xff00) | divisor;
141 b = factor & 0xff;
142
143 r = ch341_control_out(dev, 0x9a, 0x1312, a);
144 if (!r)
145 r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
146
147 return r;
148}
149
150static int ch341_set_handshake(struct usb_device *dev, u8 control)
151{
152 return ch341_control_out(dev, 0xa4, ~control, 0);
153}
154
155static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
156{
157 char *buffer;
158 int r;
159 const unsigned size = 8;
160 unsigned long flags;
161
162 buffer = kmalloc(size, GFP_KERNEL);
163 if (!buffer)
164 return -ENOMEM;
165
166 r = ch341_control_in(dev, 0x95, 0x0706, 0, buffer, size);
167 if (r < 0)
168 goto out;
169
170 /* setup the private status if available */
171 if (r == 2) {
172 r = 0;
173 spin_lock_irqsave(&priv->lock, flags);
174 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
175 spin_unlock_irqrestore(&priv->lock, flags);
176 } else
177 r = -EPROTO;
178
179out: kfree(buffer);
180 return r;
181}
182
183/* -------------------------------------------------------------------------- */
184
185static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
186{
187 char *buffer;
188 int r;
189 const unsigned size = 8;
190
191 buffer = kmalloc(size, GFP_KERNEL);
192 if (!buffer)
193 return -ENOMEM;
194
195 /* expect two bytes 0x27 0x00 */
196 r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size);
197 if (r < 0)
198 goto out;
199
200 r = ch341_control_out(dev, 0xa1, 0, 0);
201 if (r < 0)
202 goto out;
203
204 r = ch341_set_baudrate(dev, priv);
205 if (r < 0)
206 goto out;
207
208 /* expect two bytes 0x56 0x00 */
209 r = ch341_control_in(dev, 0x95, 0x2518, 0, buffer, size);
210 if (r < 0)
211 goto out;
212
213 r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050);
214 if (r < 0)
215 goto out;
216
217 /* expect 0xff 0xee */
218 r = ch341_get_status(dev, priv);
219 if (r < 0)
220 goto out;
221
222 r = ch341_control_out(dev, 0xa1, 0x501f, 0xd90a);
223 if (r < 0)
224 goto out;
225
226 r = ch341_set_baudrate(dev, priv);
227 if (r < 0)
228 goto out;
229
230 r = ch341_set_handshake(dev, priv->line_control);
231 if (r < 0)
232 goto out;
233
234 /* expect 0x9f 0xee */
235 r = ch341_get_status(dev, priv);
236
237out: kfree(buffer);
238 return r;
239}
240
241static int ch341_port_probe(struct usb_serial_port *port)
242{
243 struct ch341_private *priv;
244 int r;
245
246 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
247 if (!priv)
248 return -ENOMEM;
249
250 spin_lock_init(&priv->lock);
251 priv->baud_rate = DEFAULT_BAUD_RATE;
252 priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
253
254 r = ch341_configure(port->serial->dev, priv);
255 if (r < 0)
256 goto error;
257
258 usb_set_serial_port_data(port, priv);
259 return 0;
260
261error: kfree(priv);
262 return r;
263}
264
265static int ch341_port_remove(struct usb_serial_port *port)
266{
267 struct ch341_private *priv;
268
269 priv = usb_get_serial_port_data(port);
270 kfree(priv);
271
272 return 0;
273}
274
275static int ch341_carrier_raised(struct usb_serial_port *port)
276{
277 struct ch341_private *priv = usb_get_serial_port_data(port);
278 if (priv->line_status & CH341_BIT_DCD)
279 return 1;
280 return 0;
281}
282
283static void ch341_dtr_rts(struct usb_serial_port *port, int on)
284{
285 struct ch341_private *priv = usb_get_serial_port_data(port);
286 unsigned long flags;
287
288 /* drop DTR and RTS */
289 spin_lock_irqsave(&priv->lock, flags);
290 if (on)
291 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
292 else
293 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
294 spin_unlock_irqrestore(&priv->lock, flags);
295 ch341_set_handshake(port->serial->dev, priv->line_control);
296}
297
298static void ch341_close(struct usb_serial_port *port)
299{
300 usb_serial_generic_close(port);
301 usb_kill_urb(port->interrupt_in_urb);
302}
303
304
305/* open this device, set default parameters */
306static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
307{
308 struct usb_serial *serial = port->serial;
309 struct ch341_private *priv = usb_get_serial_port_data(port);
310 int r;
311
312 priv->baud_rate = DEFAULT_BAUD_RATE;
313
314 r = ch341_configure(serial->dev, priv);
315 if (r)
316 goto out;
317
318 r = ch341_set_handshake(serial->dev, priv->line_control);
319 if (r)
320 goto out;
321
322 r = ch341_set_baudrate(serial->dev, priv);
323 if (r)
324 goto out;
325
326 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
327 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
328 if (r) {
329 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
330 __func__, r);
331 ch341_close(port);
332 goto out;
333 }
334
335 r = usb_serial_generic_open(tty, port);
336
337out: return r;
338}
339
340/* Old_termios contains the original termios settings and
341 * tty->termios contains the new setting to be used.
342 */
343static void ch341_set_termios(struct tty_struct *tty,
344 struct usb_serial_port *port, struct ktermios *old_termios)
345{
346 struct ch341_private *priv = usb_get_serial_port_data(port);
347 unsigned baud_rate;
348 unsigned long flags;
349
350 baud_rate = tty_get_baud_rate(tty);
351
352 priv->baud_rate = baud_rate;
353
354 if (baud_rate) {
355 spin_lock_irqsave(&priv->lock, flags);
356 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
357 spin_unlock_irqrestore(&priv->lock, flags);
358 ch341_set_baudrate(port->serial->dev, priv);
359 } else {
360 spin_lock_irqsave(&priv->lock, flags);
361 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
362 spin_unlock_irqrestore(&priv->lock, flags);
363 }
364
365 ch341_set_handshake(port->serial->dev, priv->line_control);
366
367 /* Unimplemented:
368 * (cflag & CSIZE) : data bits [5, 8]
369 * (cflag & PARENB) : parity {NONE, EVEN, ODD}
370 * (cflag & CSTOPB) : stop bits [1, 2]
371 */
372}
373
374static void ch341_break_ctl(struct tty_struct *tty, int break_state)
375{
376 const uint16_t ch341_break_reg =
377 CH341_REG_BREAK1 | ((uint16_t) CH341_REG_BREAK2 << 8);
378 struct usb_serial_port *port = tty->driver_data;
379 int r;
380 uint16_t reg_contents;
381 uint8_t *break_reg;
382
383 break_reg = kmalloc(2, GFP_KERNEL);
384 if (!break_reg)
385 return;
386
387 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
388 ch341_break_reg, 0, break_reg, 2);
389 if (r < 0) {
390 dev_err(&port->dev, "%s - USB control read error (%d)\n",
391 __func__, r);
392 goto out;
393 }
394 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
395 __func__, break_reg[0], break_reg[1]);
396 if (break_state != 0) {
397 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
398 break_reg[0] &= ~CH341_NBREAK_BITS_REG1;
399 break_reg[1] &= ~CH341_NBREAK_BITS_REG2;
400 } else {
401 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
402 break_reg[0] |= CH341_NBREAK_BITS_REG1;
403 break_reg[1] |= CH341_NBREAK_BITS_REG2;
404 }
405 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
406 __func__, break_reg[0], break_reg[1]);
407 reg_contents = get_unaligned_le16(break_reg);
408 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
409 ch341_break_reg, reg_contents);
410 if (r < 0)
411 dev_err(&port->dev, "%s - USB control write error (%d)\n",
412 __func__, r);
413out:
414 kfree(break_reg);
415}
416
417static int ch341_tiocmset(struct tty_struct *tty,
418 unsigned int set, unsigned int clear)
419{
420 struct usb_serial_port *port = tty->driver_data;
421 struct ch341_private *priv = usb_get_serial_port_data(port);
422 unsigned long flags;
423 u8 control;
424
425 spin_lock_irqsave(&priv->lock, flags);
426 if (set & TIOCM_RTS)
427 priv->line_control |= CH341_BIT_RTS;
428 if (set & TIOCM_DTR)
429 priv->line_control |= CH341_BIT_DTR;
430 if (clear & TIOCM_RTS)
431 priv->line_control &= ~CH341_BIT_RTS;
432 if (clear & TIOCM_DTR)
433 priv->line_control &= ~CH341_BIT_DTR;
434 control = priv->line_control;
435 spin_unlock_irqrestore(&priv->lock, flags);
436
437 return ch341_set_handshake(port->serial->dev, control);
438}
439
440static void ch341_update_line_status(struct usb_serial_port *port,
441 unsigned char *data, size_t len)
442{
443 struct ch341_private *priv = usb_get_serial_port_data(port);
444 struct tty_struct *tty;
445 unsigned long flags;
446 u8 status;
447 u8 delta;
448
449 if (len < 4)
450 return;
451
452 status = ~data[2] & CH341_BITS_MODEM_STAT;
453
454 spin_lock_irqsave(&priv->lock, flags);
455 delta = status ^ priv->line_status;
456 priv->line_status = status;
457 spin_unlock_irqrestore(&priv->lock, flags);
458
459 if (data[1] & CH341_MULT_STAT)
460 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
461
462 if (!delta)
463 return;
464
465 if (delta & CH341_BIT_CTS)
466 port->icount.cts++;
467 if (delta & CH341_BIT_DSR)
468 port->icount.dsr++;
469 if (delta & CH341_BIT_RI)
470 port->icount.rng++;
471 if (delta & CH341_BIT_DCD) {
472 port->icount.dcd++;
473 tty = tty_port_tty_get(&port->port);
474 if (tty) {
475 usb_serial_handle_dcd_change(port, tty,
476 status & CH341_BIT_DCD);
477 tty_kref_put(tty);
478 }
479 }
480
481 wake_up_interruptible(&port->port.delta_msr_wait);
482}
483
484static void ch341_read_int_callback(struct urb *urb)
485{
486 struct usb_serial_port *port = urb->context;
487 unsigned char *data = urb->transfer_buffer;
488 unsigned int len = urb->actual_length;
489 int status;
490
491 switch (urb->status) {
492 case 0:
493 /* success */
494 break;
495 case -ECONNRESET:
496 case -ENOENT:
497 case -ESHUTDOWN:
498 /* this urb is terminated, clean up */
499 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
500 __func__, urb->status);
501 return;
502 default:
503 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
504 __func__, urb->status);
505 goto exit;
506 }
507
508 usb_serial_debug_data(&port->dev, __func__, len, data);
509 ch341_update_line_status(port, data, len);
510exit:
511 status = usb_submit_urb(urb, GFP_ATOMIC);
512 if (status) {
513 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
514 __func__, status);
515 }
516}
517
518static int ch341_tiocmget(struct tty_struct *tty)
519{
520 struct usb_serial_port *port = tty->driver_data;
521 struct ch341_private *priv = usb_get_serial_port_data(port);
522 unsigned long flags;
523 u8 mcr;
524 u8 status;
525 unsigned int result;
526
527 spin_lock_irqsave(&priv->lock, flags);
528 mcr = priv->line_control;
529 status = priv->line_status;
530 spin_unlock_irqrestore(&priv->lock, flags);
531
532 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
533 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
534 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
535 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
536 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
537 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
538
539 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
540
541 return result;
542}
543
544static int ch341_reset_resume(struct usb_serial *serial)
545{
546 struct ch341_private *priv;
547
548 priv = usb_get_serial_port_data(serial->port[0]);
549
550 /* reconfigure ch341 serial port after bus-reset */
551 ch341_configure(serial->dev, priv);
552
553 return 0;
554}
555
556static struct usb_serial_driver ch341_device = {
557 .driver = {
558 .owner = THIS_MODULE,
559 .name = "ch341-uart",
560 },
561 .id_table = id_table,
562 .num_ports = 1,
563 .open = ch341_open,
564 .dtr_rts = ch341_dtr_rts,
565 .carrier_raised = ch341_carrier_raised,
566 .close = ch341_close,
567 .set_termios = ch341_set_termios,
568 .break_ctl = ch341_break_ctl,
569 .tiocmget = ch341_tiocmget,
570 .tiocmset = ch341_tiocmset,
571 .tiocmiwait = usb_serial_generic_tiocmiwait,
572 .read_int_callback = ch341_read_int_callback,
573 .port_probe = ch341_port_probe,
574 .port_remove = ch341_port_remove,
575 .reset_resume = ch341_reset_resume,
576};
577
578static struct usb_serial_driver * const serial_drivers[] = {
579 &ch341_device, NULL
580};
581
582module_usb_serial_driver(serial_drivers, id_table);
583
584MODULE_LICENSE("GPL");