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1/*
2 * Copyright (C) 2009 by Bart Hartgers (bart.hartgers+ark3116@gmail.com)
3 * Original version:
4 * Copyright (C) 2006
5 * Simon Schulz (ark3116_driver <at> auctionant.de)
6 *
7 * ark3116
8 * - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547,
9 * productid=0x0232) (used in a datacable called KQ-U8A)
10 *
11 * Supports full modem status lines, break, hardware flow control. Does not
12 * support software flow control, since I do not know how to enable it in hw.
13 *
14 * This driver is a essentially new implementation. I initially dug
15 * into the old ark3116.c driver and suddenly realized the ark3116 is
16 * a 16450 with a USB interface glued to it. See comments at the
17 * bottom of this file.
18 *
19 * This program is free software; you can redistribute it and/or modify it
20 * under the terms of the GNU General Public License as published by the
21 * Free Software Foundation; either version 2 of the License, or (at your
22 * option) any later version.
23 */
24
25#include <linux/kernel.h>
26#include <linux/ioctl.h>
27#include <linux/tty.h>
28#include <linux/slab.h>
29#include <linux/tty_flip.h>
30#include <linux/module.h>
31#include <linux/usb.h>
32#include <linux/usb/serial.h>
33#include <linux/serial.h>
34#include <linux/serial_reg.h>
35#include <linux/uaccess.h>
36#include <linux/mutex.h>
37#include <linux/spinlock.h>
38
39#define DRIVER_AUTHOR "Bart Hartgers <bart.hartgers+ark3116@gmail.com>"
40#define DRIVER_DESC "USB ARK3116 serial/IrDA driver"
41#define DRIVER_DEV_DESC "ARK3116 RS232/IrDA"
42#define DRIVER_NAME "ark3116"
43
44/* usb timeout of 1 second */
45#define ARK_TIMEOUT 1000
46
47static const struct usb_device_id id_table[] = {
48 { USB_DEVICE(0x6547, 0x0232) },
49 { USB_DEVICE(0x18ec, 0x3118) }, /* USB to IrDA adapter */
50 { },
51};
52MODULE_DEVICE_TABLE(usb, id_table);
53
54static int is_irda(struct usb_serial *serial)
55{
56 struct usb_device *dev = serial->dev;
57 if (le16_to_cpu(dev->descriptor.idVendor) == 0x18ec &&
58 le16_to_cpu(dev->descriptor.idProduct) == 0x3118)
59 return 1;
60 return 0;
61}
62
63struct ark3116_private {
64 int irda; /* 1 for irda device */
65
66 /* protects hw register updates */
67 struct mutex hw_lock;
68
69 int quot; /* baudrate divisor */
70 __u32 lcr; /* line control register value */
71 __u32 hcr; /* handshake control register (0x8)
72 * value */
73 __u32 mcr; /* modem control register value */
74
75 /* protects the status values below */
76 spinlock_t status_lock;
77 __u32 msr; /* modem status register value */
78 __u32 lsr; /* line status register value */
79};
80
81static int ark3116_write_reg(struct usb_serial *serial,
82 unsigned reg, __u8 val)
83{
84 int result;
85 /* 0xfe 0x40 are magic values taken from original driver */
86 result = usb_control_msg(serial->dev,
87 usb_sndctrlpipe(serial->dev, 0),
88 0xfe, 0x40, val, reg,
89 NULL, 0, ARK_TIMEOUT);
90 return result;
91}
92
93static int ark3116_read_reg(struct usb_serial *serial,
94 unsigned reg, unsigned char *buf)
95{
96 int result;
97 /* 0xfe 0xc0 are magic values taken from original driver */
98 result = usb_control_msg(serial->dev,
99 usb_rcvctrlpipe(serial->dev, 0),
100 0xfe, 0xc0, 0, reg,
101 buf, 1, ARK_TIMEOUT);
102 if (result < 0)
103 return result;
104 else
105 return buf[0];
106}
107
108static inline int calc_divisor(int bps)
109{
110 /* Original ark3116 made some exceptions in rounding here
111 * because windows did the same. Assume that is not really
112 * necessary.
113 * Crystal is 12MHz, probably because of USB, but we divide by 4?
114 */
115 return (12000000 + 2*bps) / (4*bps);
116}
117
118static int ark3116_attach(struct usb_serial *serial)
119{
120 /* make sure we have our end-points */
121 if ((serial->num_bulk_in == 0) ||
122 (serial->num_bulk_out == 0) ||
123 (serial->num_interrupt_in == 0)) {
124 dev_err(&serial->dev->dev,
125 "%s - missing endpoint - "
126 "bulk in: %d, bulk out: %d, int in %d\n",
127 KBUILD_MODNAME,
128 serial->num_bulk_in,
129 serial->num_bulk_out,
130 serial->num_interrupt_in);
131 return -EINVAL;
132 }
133
134 return 0;
135}
136
137static int ark3116_port_probe(struct usb_serial_port *port)
138{
139 struct usb_serial *serial = port->serial;
140 struct ark3116_private *priv;
141
142 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
143 if (!priv)
144 return -ENOMEM;
145
146 mutex_init(&priv->hw_lock);
147 spin_lock_init(&priv->status_lock);
148
149 priv->irda = is_irda(serial);
150
151 usb_set_serial_port_data(port, priv);
152
153 /* setup the hardware */
154 ark3116_write_reg(serial, UART_IER, 0);
155 /* disable DMA */
156 ark3116_write_reg(serial, UART_FCR, 0);
157 /* handshake control */
158 priv->hcr = 0;
159 ark3116_write_reg(serial, 0x8 , 0);
160 /* modem control */
161 priv->mcr = 0;
162 ark3116_write_reg(serial, UART_MCR, 0);
163
164 if (!(priv->irda)) {
165 ark3116_write_reg(serial, 0xb , 0);
166 } else {
167 ark3116_write_reg(serial, 0xb , 1);
168 ark3116_write_reg(serial, 0xc , 0);
169 ark3116_write_reg(serial, 0xd , 0x41);
170 ark3116_write_reg(serial, 0xa , 1);
171 }
172
173 /* setup baudrate */
174 ark3116_write_reg(serial, UART_LCR, UART_LCR_DLAB);
175
176 /* setup for 9600 8N1 */
177 priv->quot = calc_divisor(9600);
178 ark3116_write_reg(serial, UART_DLL, priv->quot & 0xff);
179 ark3116_write_reg(serial, UART_DLM, (priv->quot>>8) & 0xff);
180
181 priv->lcr = UART_LCR_WLEN8;
182 ark3116_write_reg(serial, UART_LCR, UART_LCR_WLEN8);
183
184 ark3116_write_reg(serial, 0xe, 0);
185
186 if (priv->irda)
187 ark3116_write_reg(serial, 0x9, 0);
188
189 dev_info(&serial->dev->dev,
190 "%s using %s mode\n",
191 KBUILD_MODNAME,
192 priv->irda ? "IrDA" : "RS232");
193 return 0;
194}
195
196static int ark3116_port_remove(struct usb_serial_port *port)
197{
198 struct ark3116_private *priv = usb_get_serial_port_data(port);
199
200 /* device is closed, so URBs and DMA should be down */
201 mutex_destroy(&priv->hw_lock);
202 kfree(priv);
203
204 return 0;
205}
206
207static void ark3116_init_termios(struct tty_struct *tty)
208{
209 struct ktermios *termios = &tty->termios;
210 *termios = tty_std_termios;
211 termios->c_cflag = B9600 | CS8
212 | CREAD | HUPCL | CLOCAL;
213 termios->c_ispeed = 9600;
214 termios->c_ospeed = 9600;
215}
216
217static void ark3116_set_termios(struct tty_struct *tty,
218 struct usb_serial_port *port,
219 struct ktermios *old_termios)
220{
221 struct usb_serial *serial = port->serial;
222 struct ark3116_private *priv = usb_get_serial_port_data(port);
223 struct ktermios *termios = &tty->termios;
224 unsigned int cflag = termios->c_cflag;
225 int bps = tty_get_baud_rate(tty);
226 int quot;
227 __u8 lcr, hcr, eval;
228
229 /* set data bit count */
230 switch (cflag & CSIZE) {
231 case CS5:
232 lcr = UART_LCR_WLEN5;
233 break;
234 case CS6:
235 lcr = UART_LCR_WLEN6;
236 break;
237 case CS7:
238 lcr = UART_LCR_WLEN7;
239 break;
240 default:
241 case CS8:
242 lcr = UART_LCR_WLEN8;
243 break;
244 }
245 if (cflag & CSTOPB)
246 lcr |= UART_LCR_STOP;
247 if (cflag & PARENB)
248 lcr |= UART_LCR_PARITY;
249 if (!(cflag & PARODD))
250 lcr |= UART_LCR_EPAR;
251#ifdef CMSPAR
252 if (cflag & CMSPAR)
253 lcr |= UART_LCR_SPAR;
254#endif
255 /* handshake control */
256 hcr = (cflag & CRTSCTS) ? 0x03 : 0x00;
257
258 /* calc baudrate */
259 dev_dbg(&port->dev, "%s - setting bps to %d\n", __func__, bps);
260 eval = 0;
261 switch (bps) {
262 case 0:
263 quot = calc_divisor(9600);
264 break;
265 default:
266 if ((bps < 75) || (bps > 3000000))
267 bps = 9600;
268 quot = calc_divisor(bps);
269 break;
270 case 460800:
271 eval = 1;
272 quot = calc_divisor(bps);
273 break;
274 case 921600:
275 eval = 2;
276 quot = calc_divisor(bps);
277 break;
278 }
279
280 /* Update state: synchronize */
281 mutex_lock(&priv->hw_lock);
282
283 /* keep old LCR_SBC bit */
284 lcr |= (priv->lcr & UART_LCR_SBC);
285
286 dev_dbg(&port->dev, "%s - setting hcr:0x%02x,lcr:0x%02x,quot:%d\n",
287 __func__, hcr, lcr, quot);
288
289 /* handshake control */
290 if (priv->hcr != hcr) {
291 priv->hcr = hcr;
292 ark3116_write_reg(serial, 0x8, hcr);
293 }
294
295 /* baudrate */
296 if (priv->quot != quot) {
297 priv->quot = quot;
298 priv->lcr = lcr; /* need to write lcr anyway */
299
300 /* disable DMA since transmit/receive is
301 * shadowed by UART_DLL
302 */
303 ark3116_write_reg(serial, UART_FCR, 0);
304
305 ark3116_write_reg(serial, UART_LCR,
306 lcr|UART_LCR_DLAB);
307 ark3116_write_reg(serial, UART_DLL, quot & 0xff);
308 ark3116_write_reg(serial, UART_DLM, (quot>>8) & 0xff);
309
310 /* restore lcr */
311 ark3116_write_reg(serial, UART_LCR, lcr);
312 /* magic baudrate thingy: not sure what it does,
313 * but windows does this as well.
314 */
315 ark3116_write_reg(serial, 0xe, eval);
316
317 /* enable DMA */
318 ark3116_write_reg(serial, UART_FCR, UART_FCR_DMA_SELECT);
319 } else if (priv->lcr != lcr) {
320 priv->lcr = lcr;
321 ark3116_write_reg(serial, UART_LCR, lcr);
322 }
323
324 mutex_unlock(&priv->hw_lock);
325
326 /* check for software flow control */
327 if (I_IXOFF(tty) || I_IXON(tty)) {
328 dev_warn(&serial->dev->dev,
329 "%s: don't know how to do software flow control\n",
330 KBUILD_MODNAME);
331 }
332
333 /* Don't rewrite B0 */
334 if (tty_termios_baud_rate(termios))
335 tty_termios_encode_baud_rate(termios, bps, bps);
336}
337
338static void ark3116_close(struct usb_serial_port *port)
339{
340 struct usb_serial *serial = port->serial;
341
342 /* disable DMA */
343 ark3116_write_reg(serial, UART_FCR, 0);
344
345 /* deactivate interrupts */
346 ark3116_write_reg(serial, UART_IER, 0);
347
348 usb_serial_generic_close(port);
349 if (serial->num_interrupt_in)
350 usb_kill_urb(port->interrupt_in_urb);
351}
352
353static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port)
354{
355 struct ark3116_private *priv = usb_get_serial_port_data(port);
356 struct usb_serial *serial = port->serial;
357 unsigned char *buf;
358 int result;
359
360 buf = kmalloc(1, GFP_KERNEL);
361 if (buf == NULL)
362 return -ENOMEM;
363
364 result = usb_serial_generic_open(tty, port);
365 if (result) {
366 dev_dbg(&port->dev,
367 "%s - usb_serial_generic_open failed: %d\n",
368 __func__, result);
369 goto err_out;
370 }
371
372 /* remove any data still left: also clears error state */
373 ark3116_read_reg(serial, UART_RX, buf);
374
375 /* read modem status */
376 priv->msr = ark3116_read_reg(serial, UART_MSR, buf);
377 /* read line status */
378 priv->lsr = ark3116_read_reg(serial, UART_LSR, buf);
379
380 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
381 if (result) {
382 dev_err(&port->dev, "submit irq_in urb failed %d\n",
383 result);
384 ark3116_close(port);
385 goto err_out;
386 }
387
388 /* activate interrupts */
389 ark3116_write_reg(port->serial, UART_IER, UART_IER_MSI|UART_IER_RLSI);
390
391 /* enable DMA */
392 ark3116_write_reg(port->serial, UART_FCR, UART_FCR_DMA_SELECT);
393
394 /* setup termios */
395 if (tty)
396 ark3116_set_termios(tty, port, NULL);
397
398err_out:
399 kfree(buf);
400 return result;
401}
402
403static int ark3116_ioctl(struct tty_struct *tty,
404 unsigned int cmd, unsigned long arg)
405{
406 struct usb_serial_port *port = tty->driver_data;
407 struct serial_struct serstruct;
408 void __user *user_arg = (void __user *)arg;
409
410 switch (cmd) {
411 case TIOCGSERIAL:
412 /* XXX: Some of these values are probably wrong. */
413 memset(&serstruct, 0, sizeof(serstruct));
414 serstruct.type = PORT_16654;
415 serstruct.line = port->minor;
416 serstruct.port = port->port_number;
417 serstruct.custom_divisor = 0;
418 serstruct.baud_base = 460800;
419
420 if (copy_to_user(user_arg, &serstruct, sizeof(serstruct)))
421 return -EFAULT;
422
423 return 0;
424 case TIOCSSERIAL:
425 if (copy_from_user(&serstruct, user_arg, sizeof(serstruct)))
426 return -EFAULT;
427 return 0;
428 }
429
430 return -ENOIOCTLCMD;
431}
432
433static int ark3116_tiocmget(struct tty_struct *tty)
434{
435 struct usb_serial_port *port = tty->driver_data;
436 struct ark3116_private *priv = usb_get_serial_port_data(port);
437 __u32 status;
438 __u32 ctrl;
439 unsigned long flags;
440
441 mutex_lock(&priv->hw_lock);
442 ctrl = priv->mcr;
443 mutex_unlock(&priv->hw_lock);
444
445 spin_lock_irqsave(&priv->status_lock, flags);
446 status = priv->msr;
447 spin_unlock_irqrestore(&priv->status_lock, flags);
448
449 return (status & UART_MSR_DSR ? TIOCM_DSR : 0) |
450 (status & UART_MSR_CTS ? TIOCM_CTS : 0) |
451 (status & UART_MSR_RI ? TIOCM_RI : 0) |
452 (status & UART_MSR_DCD ? TIOCM_CD : 0) |
453 (ctrl & UART_MCR_DTR ? TIOCM_DTR : 0) |
454 (ctrl & UART_MCR_RTS ? TIOCM_RTS : 0) |
455 (ctrl & UART_MCR_OUT1 ? TIOCM_OUT1 : 0) |
456 (ctrl & UART_MCR_OUT2 ? TIOCM_OUT2 : 0);
457}
458
459static int ark3116_tiocmset(struct tty_struct *tty,
460 unsigned set, unsigned clr)
461{
462 struct usb_serial_port *port = tty->driver_data;
463 struct ark3116_private *priv = usb_get_serial_port_data(port);
464
465 /* we need to take the mutex here, to make sure that the value
466 * in priv->mcr is actually the one that is in the hardware
467 */
468
469 mutex_lock(&priv->hw_lock);
470
471 if (set & TIOCM_RTS)
472 priv->mcr |= UART_MCR_RTS;
473 if (set & TIOCM_DTR)
474 priv->mcr |= UART_MCR_DTR;
475 if (set & TIOCM_OUT1)
476 priv->mcr |= UART_MCR_OUT1;
477 if (set & TIOCM_OUT2)
478 priv->mcr |= UART_MCR_OUT2;
479 if (clr & TIOCM_RTS)
480 priv->mcr &= ~UART_MCR_RTS;
481 if (clr & TIOCM_DTR)
482 priv->mcr &= ~UART_MCR_DTR;
483 if (clr & TIOCM_OUT1)
484 priv->mcr &= ~UART_MCR_OUT1;
485 if (clr & TIOCM_OUT2)
486 priv->mcr &= ~UART_MCR_OUT2;
487
488 ark3116_write_reg(port->serial, UART_MCR, priv->mcr);
489
490 mutex_unlock(&priv->hw_lock);
491
492 return 0;
493}
494
495static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
496{
497 struct usb_serial_port *port = tty->driver_data;
498 struct ark3116_private *priv = usb_get_serial_port_data(port);
499
500 /* LCR is also used for other things: protect access */
501 mutex_lock(&priv->hw_lock);
502
503 if (break_state)
504 priv->lcr |= UART_LCR_SBC;
505 else
506 priv->lcr &= ~UART_LCR_SBC;
507
508 ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
509
510 mutex_unlock(&priv->hw_lock);
511}
512
513static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
514{
515 struct ark3116_private *priv = usb_get_serial_port_data(port);
516 unsigned long flags;
517
518 spin_lock_irqsave(&priv->status_lock, flags);
519 priv->msr = msr;
520 spin_unlock_irqrestore(&priv->status_lock, flags);
521
522 if (msr & UART_MSR_ANY_DELTA) {
523 /* update input line counters */
524 if (msr & UART_MSR_DCTS)
525 port->icount.cts++;
526 if (msr & UART_MSR_DDSR)
527 port->icount.dsr++;
528 if (msr & UART_MSR_DDCD)
529 port->icount.dcd++;
530 if (msr & UART_MSR_TERI)
531 port->icount.rng++;
532 wake_up_interruptible(&port->port.delta_msr_wait);
533 }
534}
535
536static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr)
537{
538 struct ark3116_private *priv = usb_get_serial_port_data(port);
539 unsigned long flags;
540
541 spin_lock_irqsave(&priv->status_lock, flags);
542 /* combine bits */
543 priv->lsr |= lsr;
544 spin_unlock_irqrestore(&priv->status_lock, flags);
545
546 if (lsr&UART_LSR_BRK_ERROR_BITS) {
547 if (lsr & UART_LSR_BI)
548 port->icount.brk++;
549 if (lsr & UART_LSR_FE)
550 port->icount.frame++;
551 if (lsr & UART_LSR_PE)
552 port->icount.parity++;
553 if (lsr & UART_LSR_OE)
554 port->icount.overrun++;
555 }
556}
557
558static void ark3116_read_int_callback(struct urb *urb)
559{
560 struct usb_serial_port *port = urb->context;
561 int status = urb->status;
562 const __u8 *data = urb->transfer_buffer;
563 int result;
564
565 switch (status) {
566 case -ECONNRESET:
567 case -ENOENT:
568 case -ESHUTDOWN:
569 /* this urb is terminated, clean up */
570 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
571 __func__, status);
572 return;
573 default:
574 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
575 __func__, status);
576 break;
577 case 0: /* success */
578 /* discovered this by trail and error... */
579 if ((urb->actual_length == 4) && (data[0] == 0xe8)) {
580 const __u8 id = data[1]&UART_IIR_ID;
581 dev_dbg(&port->dev, "%s: iir=%02x\n", __func__, data[1]);
582 if (id == UART_IIR_MSI) {
583 dev_dbg(&port->dev, "%s: msr=%02x\n",
584 __func__, data[3]);
585 ark3116_update_msr(port, data[3]);
586 break;
587 } else if (id == UART_IIR_RLSI) {
588 dev_dbg(&port->dev, "%s: lsr=%02x\n",
589 __func__, data[2]);
590 ark3116_update_lsr(port, data[2]);
591 break;
592 }
593 }
594 /*
595 * Not sure what this data meant...
596 */
597 usb_serial_debug_data(&port->dev, __func__,
598 urb->actual_length,
599 urb->transfer_buffer);
600 break;
601 }
602
603 result = usb_submit_urb(urb, GFP_ATOMIC);
604 if (result)
605 dev_err(&urb->dev->dev,
606 "%s - Error %d submitting interrupt urb\n",
607 __func__, result);
608}
609
610
611/* Data comes in via the bulk (data) URB, errors/interrupts via the int URB.
612 * This means that we cannot be sure which data byte has an associated error
613 * condition, so we report an error for all data in the next bulk read.
614 *
615 * Actually, there might even be a window between the bulk data leaving the
616 * ark and reading/resetting the lsr in the read_bulk_callback where an
617 * interrupt for the next data block could come in.
618 * Without somekind of ordering on the ark, we would have to report the
619 * error for the next block of data as well...
620 * For now, let's pretend this can't happen.
621 */
622static void ark3116_process_read_urb(struct urb *urb)
623{
624 struct usb_serial_port *port = urb->context;
625 struct ark3116_private *priv = usb_get_serial_port_data(port);
626 unsigned char *data = urb->transfer_buffer;
627 char tty_flag = TTY_NORMAL;
628 unsigned long flags;
629 __u32 lsr;
630
631 /* update line status */
632 spin_lock_irqsave(&priv->status_lock, flags);
633 lsr = priv->lsr;
634 priv->lsr &= ~UART_LSR_BRK_ERROR_BITS;
635 spin_unlock_irqrestore(&priv->status_lock, flags);
636
637 if (!urb->actual_length)
638 return;
639
640 if (lsr & UART_LSR_BRK_ERROR_BITS) {
641 if (lsr & UART_LSR_BI)
642 tty_flag = TTY_BREAK;
643 else if (lsr & UART_LSR_PE)
644 tty_flag = TTY_PARITY;
645 else if (lsr & UART_LSR_FE)
646 tty_flag = TTY_FRAME;
647
648 /* overrun is special, not associated with a char */
649 if (lsr & UART_LSR_OE)
650 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
651 }
652 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
653 urb->actual_length);
654 tty_flip_buffer_push(&port->port);
655}
656
657static struct usb_serial_driver ark3116_device = {
658 .driver = {
659 .owner = THIS_MODULE,
660 .name = "ark3116",
661 },
662 .id_table = id_table,
663 .num_ports = 1,
664 .attach = ark3116_attach,
665 .port_probe = ark3116_port_probe,
666 .port_remove = ark3116_port_remove,
667 .set_termios = ark3116_set_termios,
668 .init_termios = ark3116_init_termios,
669 .ioctl = ark3116_ioctl,
670 .tiocmget = ark3116_tiocmget,
671 .tiocmset = ark3116_tiocmset,
672 .tiocmiwait = usb_serial_generic_tiocmiwait,
673 .get_icount = usb_serial_generic_get_icount,
674 .open = ark3116_open,
675 .close = ark3116_close,
676 .break_ctl = ark3116_break_ctl,
677 .read_int_callback = ark3116_read_int_callback,
678 .process_read_urb = ark3116_process_read_urb,
679};
680
681static struct usb_serial_driver * const serial_drivers[] = {
682 &ark3116_device, NULL
683};
684
685module_usb_serial_driver(serial_drivers, id_table);
686
687MODULE_LICENSE("GPL");
688
689MODULE_AUTHOR(DRIVER_AUTHOR);
690MODULE_DESCRIPTION(DRIVER_DESC);
691
692/*
693 * The following describes what I learned from studying the old
694 * ark3116.c driver, disassembling the windows driver, and some lucky
695 * guesses. Since I do not have any datasheet or other
696 * documentation, inaccuracies are almost guaranteed.
697 *
698 * Some specs for the ARK3116 can be found here:
699 * http://web.archive.org/web/20060318000438/
700 * www.arkmicro.com/en/products/view.php?id=10
701 * On that page, 2 GPIO pins are mentioned: I assume these are the
702 * OUT1 and OUT2 pins of the UART, so I added support for those
703 * through the MCR. Since the pins are not available on my hardware,
704 * I could not verify this.
705 * Also, it states there is "on-chip hardware flow control". I have
706 * discovered how to enable that. Unfortunately, I do not know how to
707 * enable XON/XOFF (software) flow control, which would need support
708 * from the chip as well to work. Because of the wording on the web
709 * page there is a real possibility the chip simply does not support
710 * software flow control.
711 *
712 * I got my ark3116 as part of a mobile phone adapter cable. On the
713 * PCB, the following numbered contacts are present:
714 *
715 * 1:- +5V
716 * 2:o DTR
717 * 3:i RX
718 * 4:i DCD
719 * 5:o RTS
720 * 6:o TX
721 * 7:i RI
722 * 8:i DSR
723 * 10:- 0V
724 * 11:i CTS
725 *
726 * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that
727 * may be different for the one you have ;-).
728 *
729 * The windows driver limits the registers to 0-F, so I assume there
730 * are actually 16 present on the device.
731 *
732 * On an UART interrupt, 4 bytes of data come in on the interrupt
733 * endpoint. The bytes are 0xe8 IIR LSR MSR.
734 *
735 * The baudrate seems to be generated from the 12MHz crystal, using
736 * 4-times subsampling. So quot=12e6/(4*baud). Also see description
737 * of register E.
738 *
739 * Registers 0-7:
740 * These seem to be the same as for a regular 16450. The FCR is set
741 * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between
742 * the UART and the USB bridge/DMA engine.
743 *
744 * Register 8:
745 * By trial and error, I found out that bit 0 enables hardware CTS,
746 * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making
747 * RTS +5V when the 3116 cannot transfer the data to the USB bus
748 * (verified by disabling the reading URB). Note that as far as I can
749 * tell, the windows driver does NOT use this, so there might be some
750 * hardware bug or something.
751 *
752 * According to a patch provided here
753 * (http://lkml.org/lkml/2009/7/26/56), the ARK3116 can also be used
754 * as an IrDA dongle. Since I do not have such a thing, I could not
755 * investigate that aspect. However, I can speculate ;-).
756 *
757 * - IrDA encodes data differently than RS232. Most likely, one of
758 * the bits in registers 9..E enables the IR ENDEC (encoder/decoder).
759 * - Depending on the IR transceiver, the input and output need to be
760 * inverted, so there are probably bits for that as well.
761 * - IrDA is half-duplex, so there should be a bit for selecting that.
762 *
763 * This still leaves at least two registers unaccounted for. Perhaps
764 * The chip can do XON/XOFF or CRC in HW?
765 *
766 * Register 9:
767 * Set to 0x00 for IrDA, when the baudrate is initialised.
768 *
769 * Register A:
770 * Set to 0x01 for IrDA, at init.
771 *
772 * Register B:
773 * Set to 0x01 for IrDA, 0x00 for RS232, at init.
774 *
775 * Register C:
776 * Set to 00 for IrDA, at init.
777 *
778 * Register D:
779 * Set to 0x41 for IrDA, at init.
780 *
781 * Register E:
782 * Somekind of baudrate override. The windows driver seems to set
783 * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600.
784 * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer,
785 * it could be somekind of subdivisor thingy.
786 * However,it does not seem to do anything: selecting 921600 (divisor 3,
787 * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would
788 * work, but they don't.
789 *
790 * Register F: unknown
791 */
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2009 by Bart Hartgers (bart.hartgers+ark3116@gmail.com)
4 * Original version:
5 * Copyright (C) 2006
6 * Simon Schulz (ark3116_driver <at> auctionant.de)
7 *
8 * ark3116
9 * - implements a driver for the arkmicro ark3116 chipset (vendor=0x6547,
10 * productid=0x0232) (used in a datacable called KQ-U8A)
11 *
12 * Supports full modem status lines, break, hardware flow control. Does not
13 * support software flow control, since I do not know how to enable it in hw.
14 *
15 * This driver is a essentially new implementation. I initially dug
16 * into the old ark3116.c driver and suddenly realized the ark3116 is
17 * a 16450 with a USB interface glued to it. See comments at the
18 * bottom of this file.
19 */
20
21#include <linux/kernel.h>
22#include <linux/ioctl.h>
23#include <linux/tty.h>
24#include <linux/slab.h>
25#include <linux/tty_flip.h>
26#include <linux/module.h>
27#include <linux/usb.h>
28#include <linux/usb/serial.h>
29#include <linux/serial.h>
30#include <linux/serial_reg.h>
31#include <linux/uaccess.h>
32#include <linux/mutex.h>
33#include <linux/spinlock.h>
34
35#define DRIVER_AUTHOR "Bart Hartgers <bart.hartgers+ark3116@gmail.com>"
36#define DRIVER_DESC "USB ARK3116 serial/IrDA driver"
37#define DRIVER_DEV_DESC "ARK3116 RS232/IrDA"
38#define DRIVER_NAME "ark3116"
39
40/* usb timeout of 1 second */
41#define ARK_TIMEOUT 1000
42
43static const struct usb_device_id id_table[] = {
44 { USB_DEVICE(0x6547, 0x0232) },
45 { USB_DEVICE(0x18ec, 0x3118) }, /* USB to IrDA adapter */
46 { },
47};
48MODULE_DEVICE_TABLE(usb, id_table);
49
50static int is_irda(struct usb_serial *serial)
51{
52 struct usb_device *dev = serial->dev;
53 if (le16_to_cpu(dev->descriptor.idVendor) == 0x18ec &&
54 le16_to_cpu(dev->descriptor.idProduct) == 0x3118)
55 return 1;
56 return 0;
57}
58
59struct ark3116_private {
60 int irda; /* 1 for irda device */
61
62 /* protects hw register updates */
63 struct mutex hw_lock;
64
65 int quot; /* baudrate divisor */
66 __u32 lcr; /* line control register value */
67 __u32 hcr; /* handshake control register (0x8)
68 * value */
69 __u32 mcr; /* modem control register value */
70
71 /* protects the status values below */
72 spinlock_t status_lock;
73 __u32 msr; /* modem status register value */
74 __u32 lsr; /* line status register value */
75};
76
77static int ark3116_write_reg(struct usb_serial *serial,
78 unsigned reg, __u8 val)
79{
80 int result;
81 /* 0xfe 0x40 are magic values taken from original driver */
82 result = usb_control_msg(serial->dev,
83 usb_sndctrlpipe(serial->dev, 0),
84 0xfe, 0x40, val, reg,
85 NULL, 0, ARK_TIMEOUT);
86 if (result)
87 return result;
88
89 return 0;
90}
91
92static int ark3116_read_reg(struct usb_serial *serial,
93 unsigned reg, unsigned char *buf)
94{
95 int result;
96 /* 0xfe 0xc0 are magic values taken from original driver */
97 result = usb_control_msg(serial->dev,
98 usb_rcvctrlpipe(serial->dev, 0),
99 0xfe, 0xc0, 0, reg,
100 buf, 1, ARK_TIMEOUT);
101 if (result < 1) {
102 dev_err(&serial->interface->dev,
103 "failed to read register %u: %d\n",
104 reg, result);
105 if (result >= 0)
106 result = -EIO;
107
108 return result;
109 }
110
111 return 0;
112}
113
114static inline int calc_divisor(int bps)
115{
116 /* Original ark3116 made some exceptions in rounding here
117 * because windows did the same. Assume that is not really
118 * necessary.
119 * Crystal is 12MHz, probably because of USB, but we divide by 4?
120 */
121 return (12000000 + 2*bps) / (4*bps);
122}
123
124static int ark3116_port_probe(struct usb_serial_port *port)
125{
126 struct usb_serial *serial = port->serial;
127 struct ark3116_private *priv;
128
129 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
130 if (!priv)
131 return -ENOMEM;
132
133 mutex_init(&priv->hw_lock);
134 spin_lock_init(&priv->status_lock);
135
136 priv->irda = is_irda(serial);
137
138 usb_set_serial_port_data(port, priv);
139
140 /* setup the hardware */
141 ark3116_write_reg(serial, UART_IER, 0);
142 /* disable DMA */
143 ark3116_write_reg(serial, UART_FCR, 0);
144 /* handshake control */
145 priv->hcr = 0;
146 ark3116_write_reg(serial, 0x8 , 0);
147 /* modem control */
148 priv->mcr = 0;
149 ark3116_write_reg(serial, UART_MCR, 0);
150
151 if (!(priv->irda)) {
152 ark3116_write_reg(serial, 0xb , 0);
153 } else {
154 ark3116_write_reg(serial, 0xb , 1);
155 ark3116_write_reg(serial, 0xc , 0);
156 ark3116_write_reg(serial, 0xd , 0x41);
157 ark3116_write_reg(serial, 0xa , 1);
158 }
159
160 /* setup baudrate */
161 ark3116_write_reg(serial, UART_LCR, UART_LCR_DLAB);
162
163 /* setup for 9600 8N1 */
164 priv->quot = calc_divisor(9600);
165 ark3116_write_reg(serial, UART_DLL, priv->quot & 0xff);
166 ark3116_write_reg(serial, UART_DLM, (priv->quot>>8) & 0xff);
167
168 priv->lcr = UART_LCR_WLEN8;
169 ark3116_write_reg(serial, UART_LCR, UART_LCR_WLEN8);
170
171 ark3116_write_reg(serial, 0xe, 0);
172
173 if (priv->irda)
174 ark3116_write_reg(serial, 0x9, 0);
175
176 dev_info(&port->dev, "using %s mode\n", priv->irda ? "IrDA" : "RS232");
177
178 return 0;
179}
180
181static int ark3116_port_remove(struct usb_serial_port *port)
182{
183 struct ark3116_private *priv = usb_get_serial_port_data(port);
184
185 /* device is closed, so URBs and DMA should be down */
186 mutex_destroy(&priv->hw_lock);
187 kfree(priv);
188
189 return 0;
190}
191
192static void ark3116_set_termios(struct tty_struct *tty,
193 struct usb_serial_port *port,
194 struct ktermios *old_termios)
195{
196 struct usb_serial *serial = port->serial;
197 struct ark3116_private *priv = usb_get_serial_port_data(port);
198 struct ktermios *termios = &tty->termios;
199 unsigned int cflag = termios->c_cflag;
200 int bps = tty_get_baud_rate(tty);
201 int quot;
202 __u8 lcr, hcr, eval;
203
204 /* set data bit count */
205 switch (cflag & CSIZE) {
206 case CS5:
207 lcr = UART_LCR_WLEN5;
208 break;
209 case CS6:
210 lcr = UART_LCR_WLEN6;
211 break;
212 case CS7:
213 lcr = UART_LCR_WLEN7;
214 break;
215 default:
216 case CS8:
217 lcr = UART_LCR_WLEN8;
218 break;
219 }
220 if (cflag & CSTOPB)
221 lcr |= UART_LCR_STOP;
222 if (cflag & PARENB)
223 lcr |= UART_LCR_PARITY;
224 if (!(cflag & PARODD))
225 lcr |= UART_LCR_EPAR;
226#ifdef CMSPAR
227 if (cflag & CMSPAR)
228 lcr |= UART_LCR_SPAR;
229#endif
230 /* handshake control */
231 hcr = (cflag & CRTSCTS) ? 0x03 : 0x00;
232
233 /* calc baudrate */
234 dev_dbg(&port->dev, "%s - setting bps to %d\n", __func__, bps);
235 eval = 0;
236 switch (bps) {
237 case 0:
238 quot = calc_divisor(9600);
239 break;
240 default:
241 if ((bps < 75) || (bps > 3000000))
242 bps = 9600;
243 quot = calc_divisor(bps);
244 break;
245 case 460800:
246 eval = 1;
247 quot = calc_divisor(bps);
248 break;
249 case 921600:
250 eval = 2;
251 quot = calc_divisor(bps);
252 break;
253 }
254
255 /* Update state: synchronize */
256 mutex_lock(&priv->hw_lock);
257
258 /* keep old LCR_SBC bit */
259 lcr |= (priv->lcr & UART_LCR_SBC);
260
261 dev_dbg(&port->dev, "%s - setting hcr:0x%02x,lcr:0x%02x,quot:%d\n",
262 __func__, hcr, lcr, quot);
263
264 /* handshake control */
265 if (priv->hcr != hcr) {
266 priv->hcr = hcr;
267 ark3116_write_reg(serial, 0x8, hcr);
268 }
269
270 /* baudrate */
271 if (priv->quot != quot) {
272 priv->quot = quot;
273 priv->lcr = lcr; /* need to write lcr anyway */
274
275 /* disable DMA since transmit/receive is
276 * shadowed by UART_DLL
277 */
278 ark3116_write_reg(serial, UART_FCR, 0);
279
280 ark3116_write_reg(serial, UART_LCR,
281 lcr|UART_LCR_DLAB);
282 ark3116_write_reg(serial, UART_DLL, quot & 0xff);
283 ark3116_write_reg(serial, UART_DLM, (quot>>8) & 0xff);
284
285 /* restore lcr */
286 ark3116_write_reg(serial, UART_LCR, lcr);
287 /* magic baudrate thingy: not sure what it does,
288 * but windows does this as well.
289 */
290 ark3116_write_reg(serial, 0xe, eval);
291
292 /* enable DMA */
293 ark3116_write_reg(serial, UART_FCR, UART_FCR_DMA_SELECT);
294 } else if (priv->lcr != lcr) {
295 priv->lcr = lcr;
296 ark3116_write_reg(serial, UART_LCR, lcr);
297 }
298
299 mutex_unlock(&priv->hw_lock);
300
301 /* check for software flow control */
302 if (I_IXOFF(tty) || I_IXON(tty)) {
303 dev_warn(&port->dev,
304 "software flow control not implemented\n");
305 }
306
307 /* Don't rewrite B0 */
308 if (tty_termios_baud_rate(termios))
309 tty_termios_encode_baud_rate(termios, bps, bps);
310}
311
312static void ark3116_close(struct usb_serial_port *port)
313{
314 struct usb_serial *serial = port->serial;
315
316 /* disable DMA */
317 ark3116_write_reg(serial, UART_FCR, 0);
318
319 /* deactivate interrupts */
320 ark3116_write_reg(serial, UART_IER, 0);
321
322 usb_serial_generic_close(port);
323
324 usb_kill_urb(port->interrupt_in_urb);
325}
326
327static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port)
328{
329 struct ark3116_private *priv = usb_get_serial_port_data(port);
330 struct usb_serial *serial = port->serial;
331 unsigned char *buf;
332 int result;
333
334 buf = kmalloc(1, GFP_KERNEL);
335 if (buf == NULL)
336 return -ENOMEM;
337
338 result = usb_serial_generic_open(tty, port);
339 if (result) {
340 dev_dbg(&port->dev,
341 "%s - usb_serial_generic_open failed: %d\n",
342 __func__, result);
343 goto err_free;
344 }
345
346 /* remove any data still left: also clears error state */
347 ark3116_read_reg(serial, UART_RX, buf);
348
349 /* read modem status */
350 result = ark3116_read_reg(serial, UART_MSR, buf);
351 if (result)
352 goto err_close;
353 priv->msr = *buf;
354
355 /* read line status */
356 result = ark3116_read_reg(serial, UART_LSR, buf);
357 if (result)
358 goto err_close;
359 priv->lsr = *buf;
360
361 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
362 if (result) {
363 dev_err(&port->dev, "submit irq_in urb failed %d\n",
364 result);
365 goto err_close;
366 }
367
368 /* activate interrupts */
369 ark3116_write_reg(port->serial, UART_IER, UART_IER_MSI|UART_IER_RLSI);
370
371 /* enable DMA */
372 ark3116_write_reg(port->serial, UART_FCR, UART_FCR_DMA_SELECT);
373
374 /* setup termios */
375 if (tty)
376 ark3116_set_termios(tty, port, NULL);
377
378 kfree(buf);
379
380 return 0;
381
382err_close:
383 usb_serial_generic_close(port);
384err_free:
385 kfree(buf);
386
387 return result;
388}
389
390static int ark3116_get_serial_info(struct tty_struct *tty,
391 struct serial_struct *ss)
392{
393 struct usb_serial_port *port = tty->driver_data;
394
395 ss->type = PORT_16654;
396 ss->line = port->minor;
397 ss->port = port->port_number;
398 ss->baud_base = 460800;
399 return 0;
400}
401
402static int ark3116_tiocmget(struct tty_struct *tty)
403{
404 struct usb_serial_port *port = tty->driver_data;
405 struct ark3116_private *priv = usb_get_serial_port_data(port);
406 __u32 status;
407 __u32 ctrl;
408 unsigned long flags;
409
410 mutex_lock(&priv->hw_lock);
411 ctrl = priv->mcr;
412 mutex_unlock(&priv->hw_lock);
413
414 spin_lock_irqsave(&priv->status_lock, flags);
415 status = priv->msr;
416 spin_unlock_irqrestore(&priv->status_lock, flags);
417
418 return (status & UART_MSR_DSR ? TIOCM_DSR : 0) |
419 (status & UART_MSR_CTS ? TIOCM_CTS : 0) |
420 (status & UART_MSR_RI ? TIOCM_RI : 0) |
421 (status & UART_MSR_DCD ? TIOCM_CD : 0) |
422 (ctrl & UART_MCR_DTR ? TIOCM_DTR : 0) |
423 (ctrl & UART_MCR_RTS ? TIOCM_RTS : 0) |
424 (ctrl & UART_MCR_OUT1 ? TIOCM_OUT1 : 0) |
425 (ctrl & UART_MCR_OUT2 ? TIOCM_OUT2 : 0);
426}
427
428static int ark3116_tiocmset(struct tty_struct *tty,
429 unsigned set, unsigned clr)
430{
431 struct usb_serial_port *port = tty->driver_data;
432 struct ark3116_private *priv = usb_get_serial_port_data(port);
433
434 /* we need to take the mutex here, to make sure that the value
435 * in priv->mcr is actually the one that is in the hardware
436 */
437
438 mutex_lock(&priv->hw_lock);
439
440 if (set & TIOCM_RTS)
441 priv->mcr |= UART_MCR_RTS;
442 if (set & TIOCM_DTR)
443 priv->mcr |= UART_MCR_DTR;
444 if (set & TIOCM_OUT1)
445 priv->mcr |= UART_MCR_OUT1;
446 if (set & TIOCM_OUT2)
447 priv->mcr |= UART_MCR_OUT2;
448 if (clr & TIOCM_RTS)
449 priv->mcr &= ~UART_MCR_RTS;
450 if (clr & TIOCM_DTR)
451 priv->mcr &= ~UART_MCR_DTR;
452 if (clr & TIOCM_OUT1)
453 priv->mcr &= ~UART_MCR_OUT1;
454 if (clr & TIOCM_OUT2)
455 priv->mcr &= ~UART_MCR_OUT2;
456
457 ark3116_write_reg(port->serial, UART_MCR, priv->mcr);
458
459 mutex_unlock(&priv->hw_lock);
460
461 return 0;
462}
463
464static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
465{
466 struct usb_serial_port *port = tty->driver_data;
467 struct ark3116_private *priv = usb_get_serial_port_data(port);
468
469 /* LCR is also used for other things: protect access */
470 mutex_lock(&priv->hw_lock);
471
472 if (break_state)
473 priv->lcr |= UART_LCR_SBC;
474 else
475 priv->lcr &= ~UART_LCR_SBC;
476
477 ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
478
479 mutex_unlock(&priv->hw_lock);
480}
481
482static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
483{
484 struct ark3116_private *priv = usb_get_serial_port_data(port);
485 unsigned long flags;
486
487 spin_lock_irqsave(&priv->status_lock, flags);
488 priv->msr = msr;
489 spin_unlock_irqrestore(&priv->status_lock, flags);
490
491 if (msr & UART_MSR_ANY_DELTA) {
492 /* update input line counters */
493 if (msr & UART_MSR_DCTS)
494 port->icount.cts++;
495 if (msr & UART_MSR_DDSR)
496 port->icount.dsr++;
497 if (msr & UART_MSR_DDCD)
498 port->icount.dcd++;
499 if (msr & UART_MSR_TERI)
500 port->icount.rng++;
501 wake_up_interruptible(&port->port.delta_msr_wait);
502 }
503}
504
505static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr)
506{
507 struct ark3116_private *priv = usb_get_serial_port_data(port);
508 unsigned long flags;
509
510 spin_lock_irqsave(&priv->status_lock, flags);
511 /* combine bits */
512 priv->lsr |= lsr;
513 spin_unlock_irqrestore(&priv->status_lock, flags);
514
515 if (lsr&UART_LSR_BRK_ERROR_BITS) {
516 if (lsr & UART_LSR_BI)
517 port->icount.brk++;
518 if (lsr & UART_LSR_FE)
519 port->icount.frame++;
520 if (lsr & UART_LSR_PE)
521 port->icount.parity++;
522 if (lsr & UART_LSR_OE)
523 port->icount.overrun++;
524 }
525}
526
527static void ark3116_read_int_callback(struct urb *urb)
528{
529 struct usb_serial_port *port = urb->context;
530 int status = urb->status;
531 const __u8 *data = urb->transfer_buffer;
532 int result;
533
534 switch (status) {
535 case -ECONNRESET:
536 case -ENOENT:
537 case -ESHUTDOWN:
538 /* this urb is terminated, clean up */
539 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
540 __func__, status);
541 return;
542 default:
543 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
544 __func__, status);
545 break;
546 case 0: /* success */
547 /* discovered this by trail and error... */
548 if ((urb->actual_length == 4) && (data[0] == 0xe8)) {
549 const __u8 id = data[1]&UART_IIR_ID;
550 dev_dbg(&port->dev, "%s: iir=%02x\n", __func__, data[1]);
551 if (id == UART_IIR_MSI) {
552 dev_dbg(&port->dev, "%s: msr=%02x\n",
553 __func__, data[3]);
554 ark3116_update_msr(port, data[3]);
555 break;
556 } else if (id == UART_IIR_RLSI) {
557 dev_dbg(&port->dev, "%s: lsr=%02x\n",
558 __func__, data[2]);
559 ark3116_update_lsr(port, data[2]);
560 break;
561 }
562 }
563 /*
564 * Not sure what this data meant...
565 */
566 usb_serial_debug_data(&port->dev, __func__,
567 urb->actual_length,
568 urb->transfer_buffer);
569 break;
570 }
571
572 result = usb_submit_urb(urb, GFP_ATOMIC);
573 if (result)
574 dev_err(&port->dev, "failed to resubmit interrupt urb: %d\n",
575 result);
576}
577
578
579/* Data comes in via the bulk (data) URB, errors/interrupts via the int URB.
580 * This means that we cannot be sure which data byte has an associated error
581 * condition, so we report an error for all data in the next bulk read.
582 *
583 * Actually, there might even be a window between the bulk data leaving the
584 * ark and reading/resetting the lsr in the read_bulk_callback where an
585 * interrupt for the next data block could come in.
586 * Without somekind of ordering on the ark, we would have to report the
587 * error for the next block of data as well...
588 * For now, let's pretend this can't happen.
589 */
590static void ark3116_process_read_urb(struct urb *urb)
591{
592 struct usb_serial_port *port = urb->context;
593 struct ark3116_private *priv = usb_get_serial_port_data(port);
594 unsigned char *data = urb->transfer_buffer;
595 char tty_flag = TTY_NORMAL;
596 unsigned long flags;
597 __u32 lsr;
598
599 /* update line status */
600 spin_lock_irqsave(&priv->status_lock, flags);
601 lsr = priv->lsr;
602 priv->lsr &= ~UART_LSR_BRK_ERROR_BITS;
603 spin_unlock_irqrestore(&priv->status_lock, flags);
604
605 if (!urb->actual_length)
606 return;
607
608 if (lsr & UART_LSR_BRK_ERROR_BITS) {
609 if (lsr & UART_LSR_BI)
610 tty_flag = TTY_BREAK;
611 else if (lsr & UART_LSR_PE)
612 tty_flag = TTY_PARITY;
613 else if (lsr & UART_LSR_FE)
614 tty_flag = TTY_FRAME;
615
616 /* overrun is special, not associated with a char */
617 if (lsr & UART_LSR_OE)
618 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
619 }
620 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
621 urb->actual_length);
622 tty_flip_buffer_push(&port->port);
623}
624
625static struct usb_serial_driver ark3116_device = {
626 .driver = {
627 .owner = THIS_MODULE,
628 .name = "ark3116",
629 },
630 .id_table = id_table,
631 .num_ports = 1,
632 .num_bulk_in = 1,
633 .num_bulk_out = 1,
634 .num_interrupt_in = 1,
635 .port_probe = ark3116_port_probe,
636 .port_remove = ark3116_port_remove,
637 .set_termios = ark3116_set_termios,
638 .get_serial = ark3116_get_serial_info,
639 .tiocmget = ark3116_tiocmget,
640 .tiocmset = ark3116_tiocmset,
641 .tiocmiwait = usb_serial_generic_tiocmiwait,
642 .get_icount = usb_serial_generic_get_icount,
643 .open = ark3116_open,
644 .close = ark3116_close,
645 .break_ctl = ark3116_break_ctl,
646 .read_int_callback = ark3116_read_int_callback,
647 .process_read_urb = ark3116_process_read_urb,
648};
649
650static struct usb_serial_driver * const serial_drivers[] = {
651 &ark3116_device, NULL
652};
653
654module_usb_serial_driver(serial_drivers, id_table);
655
656MODULE_LICENSE("GPL");
657
658MODULE_AUTHOR(DRIVER_AUTHOR);
659MODULE_DESCRIPTION(DRIVER_DESC);
660
661/*
662 * The following describes what I learned from studying the old
663 * ark3116.c driver, disassembling the windows driver, and some lucky
664 * guesses. Since I do not have any datasheet or other
665 * documentation, inaccuracies are almost guaranteed.
666 *
667 * Some specs for the ARK3116 can be found here:
668 * http://web.archive.org/web/20060318000438/
669 * www.arkmicro.com/en/products/view.php?id=10
670 * On that page, 2 GPIO pins are mentioned: I assume these are the
671 * OUT1 and OUT2 pins of the UART, so I added support for those
672 * through the MCR. Since the pins are not available on my hardware,
673 * I could not verify this.
674 * Also, it states there is "on-chip hardware flow control". I have
675 * discovered how to enable that. Unfortunately, I do not know how to
676 * enable XON/XOFF (software) flow control, which would need support
677 * from the chip as well to work. Because of the wording on the web
678 * page there is a real possibility the chip simply does not support
679 * software flow control.
680 *
681 * I got my ark3116 as part of a mobile phone adapter cable. On the
682 * PCB, the following numbered contacts are present:
683 *
684 * 1:- +5V
685 * 2:o DTR
686 * 3:i RX
687 * 4:i DCD
688 * 5:o RTS
689 * 6:o TX
690 * 7:i RI
691 * 8:i DSR
692 * 10:- 0V
693 * 11:i CTS
694 *
695 * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that
696 * may be different for the one you have ;-).
697 *
698 * The windows driver limits the registers to 0-F, so I assume there
699 * are actually 16 present on the device.
700 *
701 * On an UART interrupt, 4 bytes of data come in on the interrupt
702 * endpoint. The bytes are 0xe8 IIR LSR MSR.
703 *
704 * The baudrate seems to be generated from the 12MHz crystal, using
705 * 4-times subsampling. So quot=12e6/(4*baud). Also see description
706 * of register E.
707 *
708 * Registers 0-7:
709 * These seem to be the same as for a regular 16450. The FCR is set
710 * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between
711 * the UART and the USB bridge/DMA engine.
712 *
713 * Register 8:
714 * By trial and error, I found out that bit 0 enables hardware CTS,
715 * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making
716 * RTS +5V when the 3116 cannot transfer the data to the USB bus
717 * (verified by disabling the reading URB). Note that as far as I can
718 * tell, the windows driver does NOT use this, so there might be some
719 * hardware bug or something.
720 *
721 * According to a patch provided here
722 * (http://lkml.org/lkml/2009/7/26/56), the ARK3116 can also be used
723 * as an IrDA dongle. Since I do not have such a thing, I could not
724 * investigate that aspect. However, I can speculate ;-).
725 *
726 * - IrDA encodes data differently than RS232. Most likely, one of
727 * the bits in registers 9..E enables the IR ENDEC (encoder/decoder).
728 * - Depending on the IR transceiver, the input and output need to be
729 * inverted, so there are probably bits for that as well.
730 * - IrDA is half-duplex, so there should be a bit for selecting that.
731 *
732 * This still leaves at least two registers unaccounted for. Perhaps
733 * The chip can do XON/XOFF or CRC in HW?
734 *
735 * Register 9:
736 * Set to 0x00 for IrDA, when the baudrate is initialised.
737 *
738 * Register A:
739 * Set to 0x01 for IrDA, at init.
740 *
741 * Register B:
742 * Set to 0x01 for IrDA, 0x00 for RS232, at init.
743 *
744 * Register C:
745 * Set to 00 for IrDA, at init.
746 *
747 * Register D:
748 * Set to 0x41 for IrDA, at init.
749 *
750 * Register E:
751 * Somekind of baudrate override. The windows driver seems to set
752 * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600.
753 * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer,
754 * it could be somekind of subdivisor thingy.
755 * However,it does not seem to do anything: selecting 921600 (divisor 3,
756 * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would
757 * work, but they don't.
758 *
759 * Register F: unknown
760 */