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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/*
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_READ_VERSION 0x5F
65#define CH341_REQ_WRITE_REG 0x9A
66#define CH341_REQ_READ_REG 0x95
67#define CH341_REQ_SERIAL_INIT 0xA1
68#define CH341_REQ_MODEM_CTRL 0xA4
69
70#define CH341_REG_BREAK 0x05
71#define CH341_REG_LCR 0x18
72#define CH341_NBREAK_BITS 0x01
73
74#define CH341_LCR_ENABLE_RX 0x80
75#define CH341_LCR_ENABLE_TX 0x40
76#define CH341_LCR_MARK_SPACE 0x20
77#define CH341_LCR_PAR_EVEN 0x10
78#define CH341_LCR_ENABLE_PAR 0x08
79#define CH341_LCR_STOP_BITS_2 0x04
80#define CH341_LCR_CS8 0x03
81#define CH341_LCR_CS7 0x02
82#define CH341_LCR_CS6 0x01
83#define CH341_LCR_CS5 0x00
84
85static const struct usb_device_id id_table[] = {
86 { USB_DEVICE(0x4348, 0x5523) },
87 { USB_DEVICE(0x1a86, 0x7523) },
88 { USB_DEVICE(0x1a86, 0x5523) },
89 { },
90};
91MODULE_DEVICE_TABLE(usb, id_table);
92
93struct ch341_private {
94 spinlock_t lock; /* access lock */
95 unsigned baud_rate; /* set baud rate */
96 u8 line_control; /* set line control value RTS/DTR */
97 u8 line_status; /* active status of modem control inputs */
98 u8 lcr;
99};
100
101static void ch341_set_termios(struct tty_struct *tty,
102 struct usb_serial_port *port,
103 struct ktermios *old_termios);
104
105static int ch341_control_out(struct usb_device *dev, u8 request,
106 u16 value, u16 index)
107{
108 int r;
109
110 dev_dbg(&dev->dev, "ch341_control_out(%02x,%02x,%04x,%04x)\n",
111 USB_DIR_OUT|0x40, (int)request, (int)value, (int)index);
112
113 r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request,
114 USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT,
115 value, index, NULL, 0, DEFAULT_TIMEOUT);
116 if (r < 0)
117 dev_err(&dev->dev, "failed to send control message: %d\n", r);
118
119 return r;
120}
121
122static int ch341_control_in(struct usb_device *dev,
123 u8 request, u16 value, u16 index,
124 char *buf, unsigned bufsize)
125{
126 int r;
127
128 dev_dbg(&dev->dev, "ch341_control_in(%02x,%02x,%04x,%04x,%p,%u)\n",
129 USB_DIR_IN|0x40, (int)request, (int)value, (int)index, buf,
130 (int)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 < 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
151static int ch341_set_baudrate_lcr(struct usb_device *dev,
152 struct ch341_private *priv, u8 lcr)
153{
154 short a;
155 int r;
156 unsigned long factor;
157 short divisor;
158
159 if (!priv->baud_rate)
160 return -EINVAL;
161 factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
162 divisor = CH341_BAUDBASE_DIVMAX;
163
164 while ((factor > 0xfff0) && divisor) {
165 factor >>= 3;
166 divisor--;
167 }
168
169 if (factor > 0xfff0)
170 return -EINVAL;
171
172 factor = 0x10000 - factor;
173 a = (factor & 0xff00) | divisor;
174
175 /*
176 * CH341A buffers data until a full endpoint-size packet (32 bytes)
177 * has been received unless bit 7 is set.
178 */
179 a |= BIT(7);
180
181 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x1312, a);
182 if (r)
183 return r;
184
185 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, lcr);
186 if (r)
187 return r;
188
189 return r;
190}
191
192static int ch341_set_handshake(struct usb_device *dev, u8 control)
193{
194 return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0);
195}
196
197static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
198{
199 const unsigned int size = 2;
200 char *buffer;
201 int r;
202 unsigned long flags;
203
204 buffer = kmalloc(size, GFP_KERNEL);
205 if (!buffer)
206 return -ENOMEM;
207
208 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size);
209 if (r < 0)
210 goto out;
211
212 spin_lock_irqsave(&priv->lock, flags);
213 priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
214 spin_unlock_irqrestore(&priv->lock, flags);
215
216out: kfree(buffer);
217 return r;
218}
219
220/* -------------------------------------------------------------------------- */
221
222static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
223{
224 const unsigned int size = 2;
225 char *buffer;
226 int r;
227
228 buffer = kmalloc(size, GFP_KERNEL);
229 if (!buffer)
230 return -ENOMEM;
231
232 /* expect two bytes 0x27 0x00 */
233 r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size);
234 if (r < 0)
235 goto out;
236 dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]);
237
238 r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0);
239 if (r < 0)
240 goto out;
241
242 /* expect two bytes 0x56 0x00 */
243 r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x2518, 0, buffer, size);
244 if (r < 0)
245 goto out;
246
247 r = ch341_control_out(dev, CH341_REQ_WRITE_REG, 0x2518, 0x0050);
248 if (r < 0)
249 goto out;
250
251 /* expect 0xff 0xee */
252 r = ch341_get_status(dev, priv);
253 if (r < 0)
254 goto out;
255
256 r = ch341_set_baudrate_lcr(dev, priv, priv->lcr);
257 if (r < 0)
258 goto out;
259
260 r = ch341_set_handshake(dev, priv->line_control);
261 if (r < 0)
262 goto out;
263
264 /* expect 0x9f 0xee */
265 r = ch341_get_status(dev, priv);
266
267out: kfree(buffer);
268 return r;
269}
270
271static int ch341_port_probe(struct usb_serial_port *port)
272{
273 struct ch341_private *priv;
274 int r;
275
276 priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL);
277 if (!priv)
278 return -ENOMEM;
279
280 spin_lock_init(&priv->lock);
281 priv->baud_rate = DEFAULT_BAUD_RATE;
282
283 r = ch341_configure(port->serial->dev, priv);
284 if (r < 0)
285 goto error;
286
287 usb_set_serial_port_data(port, priv);
288 return 0;
289
290error: kfree(priv);
291 return r;
292}
293
294static int ch341_port_remove(struct usb_serial_port *port)
295{
296 struct ch341_private *priv;
297
298 priv = usb_get_serial_port_data(port);
299 kfree(priv);
300
301 return 0;
302}
303
304static int ch341_carrier_raised(struct usb_serial_port *port)
305{
306 struct ch341_private *priv = usb_get_serial_port_data(port);
307 if (priv->line_status & CH341_BIT_DCD)
308 return 1;
309 return 0;
310}
311
312static void ch341_dtr_rts(struct usb_serial_port *port, int on)
313{
314 struct ch341_private *priv = usb_get_serial_port_data(port);
315 unsigned long flags;
316
317 /* drop DTR and RTS */
318 spin_lock_irqsave(&priv->lock, flags);
319 if (on)
320 priv->line_control |= CH341_BIT_RTS | CH341_BIT_DTR;
321 else
322 priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
323 spin_unlock_irqrestore(&priv->lock, flags);
324 ch341_set_handshake(port->serial->dev, priv->line_control);
325}
326
327static void ch341_close(struct usb_serial_port *port)
328{
329 usb_serial_generic_close(port);
330 usb_kill_urb(port->interrupt_in_urb);
331}
332
333
334/* open this device, set default parameters */
335static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port)
336{
337 struct usb_serial *serial = port->serial;
338 struct ch341_private *priv = usb_get_serial_port_data(port);
339 int r;
340
341 r = ch341_configure(serial->dev, priv);
342 if (r)
343 return r;
344
345 if (tty)
346 ch341_set_termios(tty, port, NULL);
347
348 dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__);
349 r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
350 if (r) {
351 dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n",
352 __func__, r);
353 return r;
354 }
355
356 r = usb_serial_generic_open(tty, port);
357 if (r)
358 goto err_kill_interrupt_urb;
359
360 return 0;
361
362err_kill_interrupt_urb:
363 usb_kill_urb(port->interrupt_in_urb);
364
365 return r;
366}
367
368/* Old_termios contains the original termios settings and
369 * tty->termios contains the new setting to be used.
370 */
371static void ch341_set_termios(struct tty_struct *tty,
372 struct usb_serial_port *port, struct ktermios *old_termios)
373{
374 struct ch341_private *priv = usb_get_serial_port_data(port);
375 unsigned baud_rate;
376 unsigned long flags;
377 unsigned char ctrl;
378 int r;
379
380 /* redundant changes may cause the chip to lose bytes */
381 if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
382 return;
383
384 baud_rate = tty_get_baud_rate(tty);
385
386 ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
387
388 switch (C_CSIZE(tty)) {
389 case CS5:
390 ctrl |= CH341_LCR_CS5;
391 break;
392 case CS6:
393 ctrl |= CH341_LCR_CS6;
394 break;
395 case CS7:
396 ctrl |= CH341_LCR_CS7;
397 break;
398 case CS8:
399 ctrl |= CH341_LCR_CS8;
400 break;
401 }
402
403 if (C_PARENB(tty)) {
404 ctrl |= CH341_LCR_ENABLE_PAR;
405 if (C_PARODD(tty) == 0)
406 ctrl |= CH341_LCR_PAR_EVEN;
407 if (C_CMSPAR(tty))
408 ctrl |= CH341_LCR_MARK_SPACE;
409 }
410
411 if (C_CSTOPB(tty))
412 ctrl |= CH341_LCR_STOP_BITS_2;
413
414 if (baud_rate) {
415 priv->baud_rate = baud_rate;
416
417 r = ch341_set_baudrate_lcr(port->serial->dev, priv, ctrl);
418 if (r < 0 && old_termios) {
419 priv->baud_rate = tty_termios_baud_rate(old_termios);
420 tty_termios_copy_hw(&tty->termios, old_termios);
421 } else if (r == 0) {
422 priv->lcr = ctrl;
423 }
424 }
425
426 spin_lock_irqsave(&priv->lock, flags);
427 if (C_BAUD(tty) == B0)
428 priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
429 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
430 priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
431 spin_unlock_irqrestore(&priv->lock, flags);
432
433 ch341_set_handshake(port->serial->dev, priv->line_control);
434}
435
436static void ch341_break_ctl(struct tty_struct *tty, int break_state)
437{
438 const uint16_t ch341_break_reg =
439 ((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK;
440 struct usb_serial_port *port = tty->driver_data;
441 int r;
442 uint16_t reg_contents;
443 uint8_t *break_reg;
444
445 break_reg = kmalloc(2, GFP_KERNEL);
446 if (!break_reg)
447 return;
448
449 r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG,
450 ch341_break_reg, 0, break_reg, 2);
451 if (r < 0) {
452 dev_err(&port->dev, "%s - USB control read error (%d)\n",
453 __func__, r);
454 goto out;
455 }
456 dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n",
457 __func__, break_reg[0], break_reg[1]);
458 if (break_state != 0) {
459 dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__);
460 break_reg[0] &= ~CH341_NBREAK_BITS;
461 break_reg[1] &= ~CH341_LCR_ENABLE_TX;
462 } else {
463 dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__);
464 break_reg[0] |= CH341_NBREAK_BITS;
465 break_reg[1] |= CH341_LCR_ENABLE_TX;
466 }
467 dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n",
468 __func__, break_reg[0], break_reg[1]);
469 reg_contents = get_unaligned_le16(break_reg);
470 r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG,
471 ch341_break_reg, reg_contents);
472 if (r < 0)
473 dev_err(&port->dev, "%s - USB control write error (%d)\n",
474 __func__, r);
475out:
476 kfree(break_reg);
477}
478
479static int ch341_tiocmset(struct tty_struct *tty,
480 unsigned int set, unsigned int clear)
481{
482 struct usb_serial_port *port = tty->driver_data;
483 struct ch341_private *priv = usb_get_serial_port_data(port);
484 unsigned long flags;
485 u8 control;
486
487 spin_lock_irqsave(&priv->lock, flags);
488 if (set & TIOCM_RTS)
489 priv->line_control |= CH341_BIT_RTS;
490 if (set & TIOCM_DTR)
491 priv->line_control |= CH341_BIT_DTR;
492 if (clear & TIOCM_RTS)
493 priv->line_control &= ~CH341_BIT_RTS;
494 if (clear & TIOCM_DTR)
495 priv->line_control &= ~CH341_BIT_DTR;
496 control = priv->line_control;
497 spin_unlock_irqrestore(&priv->lock, flags);
498
499 return ch341_set_handshake(port->serial->dev, control);
500}
501
502static void ch341_update_line_status(struct usb_serial_port *port,
503 unsigned char *data, size_t len)
504{
505 struct ch341_private *priv = usb_get_serial_port_data(port);
506 struct tty_struct *tty;
507 unsigned long flags;
508 u8 status;
509 u8 delta;
510
511 if (len < 4)
512 return;
513
514 status = ~data[2] & CH341_BITS_MODEM_STAT;
515
516 spin_lock_irqsave(&priv->lock, flags);
517 delta = status ^ priv->line_status;
518 priv->line_status = status;
519 spin_unlock_irqrestore(&priv->lock, flags);
520
521 if (data[1] & CH341_MULT_STAT)
522 dev_dbg(&port->dev, "%s - multiple status change\n", __func__);
523
524 if (!delta)
525 return;
526
527 if (delta & CH341_BIT_CTS)
528 port->icount.cts++;
529 if (delta & CH341_BIT_DSR)
530 port->icount.dsr++;
531 if (delta & CH341_BIT_RI)
532 port->icount.rng++;
533 if (delta & CH341_BIT_DCD) {
534 port->icount.dcd++;
535 tty = tty_port_tty_get(&port->port);
536 if (tty) {
537 usb_serial_handle_dcd_change(port, tty,
538 status & CH341_BIT_DCD);
539 tty_kref_put(tty);
540 }
541 }
542
543 wake_up_interruptible(&port->port.delta_msr_wait);
544}
545
546static void ch341_read_int_callback(struct urb *urb)
547{
548 struct usb_serial_port *port = urb->context;
549 unsigned char *data = urb->transfer_buffer;
550 unsigned int len = urb->actual_length;
551 int status;
552
553 switch (urb->status) {
554 case 0:
555 /* success */
556 break;
557 case -ECONNRESET:
558 case -ENOENT:
559 case -ESHUTDOWN:
560 /* this urb is terminated, clean up */
561 dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n",
562 __func__, urb->status);
563 return;
564 default:
565 dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n",
566 __func__, urb->status);
567 goto exit;
568 }
569
570 usb_serial_debug_data(&port->dev, __func__, len, data);
571 ch341_update_line_status(port, data, len);
572exit:
573 status = usb_submit_urb(urb, GFP_ATOMIC);
574 if (status) {
575 dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n",
576 __func__, status);
577 }
578}
579
580static int ch341_tiocmget(struct tty_struct *tty)
581{
582 struct usb_serial_port *port = tty->driver_data;
583 struct ch341_private *priv = usb_get_serial_port_data(port);
584 unsigned long flags;
585 u8 mcr;
586 u8 status;
587 unsigned int result;
588
589 spin_lock_irqsave(&priv->lock, flags);
590 mcr = priv->line_control;
591 status = priv->line_status;
592 spin_unlock_irqrestore(&priv->lock, flags);
593
594 result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0)
595 | ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0)
596 | ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0)
597 | ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0)
598 | ((status & CH341_BIT_RI) ? TIOCM_RI : 0)
599 | ((status & CH341_BIT_DCD) ? TIOCM_CD : 0);
600
601 dev_dbg(&port->dev, "%s - result = %x\n", __func__, result);
602
603 return result;
604}
605
606static int ch341_reset_resume(struct usb_serial *serial)
607{
608 struct usb_serial_port *port = serial->port[0];
609 struct ch341_private *priv = usb_get_serial_port_data(port);
610 int ret;
611
612 /* reconfigure ch341 serial port after bus-reset */
613 ch341_configure(serial->dev, priv);
614
615 if (tty_port_initialized(&port->port)) {
616 ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
617 if (ret) {
618 dev_err(&port->dev, "failed to submit interrupt urb: %d\n",
619 ret);
620 return ret;
621 }
622 }
623
624 return usb_serial_generic_resume(serial);
625}
626
627static struct usb_serial_driver ch341_device = {
628 .driver = {
629 .owner = THIS_MODULE,
630 .name = "ch341-uart",
631 },
632 .id_table = id_table,
633 .num_ports = 1,
634 .open = ch341_open,
635 .dtr_rts = ch341_dtr_rts,
636 .carrier_raised = ch341_carrier_raised,
637 .close = ch341_close,
638 .set_termios = ch341_set_termios,
639 .break_ctl = ch341_break_ctl,
640 .tiocmget = ch341_tiocmget,
641 .tiocmset = ch341_tiocmset,
642 .tiocmiwait = usb_serial_generic_tiocmiwait,
643 .read_int_callback = ch341_read_int_callback,
644 .port_probe = ch341_port_probe,
645 .port_remove = ch341_port_remove,
646 .reset_resume = ch341_reset_resume,
647};
648
649static struct usb_serial_driver * const serial_drivers[] = {
650 &ch341_device, NULL
651};
652
653module_usb_serial_driver(serial_drivers, id_table);
654
655MODULE_LICENSE("GPL");