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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_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");