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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/init.h>
27#include <linux/ioctl.h>
28#include <linux/tty.h>
29#include <linux/slab.h>
30#include <linux/tty_flip.h>
31#include <linux/module.h>
32#include <linux/usb.h>
33#include <linux/usb/serial.h>
34#include <linux/serial.h>
35#include <linux/serial_reg.h>
36#include <linux/uaccess.h>
37#include <linux/mutex.h>
38#include <linux/spinlock.h>
39
40static int debug;
41/*
42 * Version information
43 */
44
45#define DRIVER_VERSION "v0.6"
46#define DRIVER_AUTHOR "Bart Hartgers <bart.hartgers+ark3116@gmail.com>"
47#define DRIVER_DESC "USB ARK3116 serial/IrDA driver"
48#define DRIVER_DEV_DESC "ARK3116 RS232/IrDA"
49#define DRIVER_NAME "ark3116"
50
51/* usb timeout of 1 second */
52#define ARK_TIMEOUT (1*HZ)
53
54static const struct usb_device_id id_table[] = {
55 { USB_DEVICE(0x6547, 0x0232) },
56 { USB_DEVICE(0x18ec, 0x3118) }, /* USB to IrDA adapter */
57 { },
58};
59MODULE_DEVICE_TABLE(usb, id_table);
60
61static int is_irda(struct usb_serial *serial)
62{
63 struct usb_device *dev = serial->dev;
64 if (le16_to_cpu(dev->descriptor.idVendor) == 0x18ec &&
65 le16_to_cpu(dev->descriptor.idProduct) == 0x3118)
66 return 1;
67 return 0;
68}
69
70struct ark3116_private {
71 wait_queue_head_t delta_msr_wait;
72 struct async_icount icount;
73 int irda; /* 1 for irda device */
74
75 /* protects hw register updates */
76 struct mutex hw_lock;
77
78 int quot; /* baudrate divisor */
79 __u32 lcr; /* line control register value */
80 __u32 hcr; /* handshake control register (0x8)
81 * value */
82 __u32 mcr; /* modem contol register value */
83
84 /* protects the status values below */
85 spinlock_t status_lock;
86 __u32 msr; /* modem status register value */
87 __u32 lsr; /* line status register value */
88};
89
90static int ark3116_write_reg(struct usb_serial *serial,
91 unsigned reg, __u8 val)
92{
93 int result;
94 /* 0xfe 0x40 are magic values taken from original driver */
95 result = usb_control_msg(serial->dev,
96 usb_sndctrlpipe(serial->dev, 0),
97 0xfe, 0x40, val, reg,
98 NULL, 0, ARK_TIMEOUT);
99 return result;
100}
101
102static int ark3116_read_reg(struct usb_serial *serial,
103 unsigned reg, unsigned char *buf)
104{
105 int result;
106 /* 0xfe 0xc0 are magic values taken from original driver */
107 result = usb_control_msg(serial->dev,
108 usb_rcvctrlpipe(serial->dev, 0),
109 0xfe, 0xc0, 0, reg,
110 buf, 1, ARK_TIMEOUT);
111 if (result < 0)
112 return result;
113 else
114 return buf[0];
115}
116
117static inline int calc_divisor(int bps)
118{
119 /* Original ark3116 made some exceptions in rounding here
120 * because windows did the same. Assume that is not really
121 * necessary.
122 * Crystal is 12MHz, probably because of USB, but we divide by 4?
123 */
124 return (12000000 + 2*bps) / (4*bps);
125}
126
127static int ark3116_attach(struct usb_serial *serial)
128{
129 struct usb_serial_port *port = serial->port[0];
130 struct ark3116_private *priv;
131
132 /* make sure we have our end-points */
133 if ((serial->num_bulk_in == 0) ||
134 (serial->num_bulk_out == 0) ||
135 (serial->num_interrupt_in == 0)) {
136 dev_err(&serial->dev->dev,
137 "%s - missing endpoint - "
138 "bulk in: %d, bulk out: %d, int in %d\n",
139 KBUILD_MODNAME,
140 serial->num_bulk_in,
141 serial->num_bulk_out,
142 serial->num_interrupt_in);
143 return -EINVAL;
144 }
145
146 priv = kzalloc(sizeof(struct ark3116_private),
147 GFP_KERNEL);
148 if (!priv)
149 return -ENOMEM;
150
151 init_waitqueue_head(&priv->delta_msr_wait);
152 mutex_init(&priv->hw_lock);
153 spin_lock_init(&priv->status_lock);
154
155 priv->irda = is_irda(serial);
156
157 usb_set_serial_port_data(port, priv);
158
159 /* setup the hardware */
160 ark3116_write_reg(serial, UART_IER, 0);
161 /* disable DMA */
162 ark3116_write_reg(serial, UART_FCR, 0);
163 /* handshake control */
164 priv->hcr = 0;
165 ark3116_write_reg(serial, 0x8 , 0);
166 /* modem control */
167 priv->mcr = 0;
168 ark3116_write_reg(serial, UART_MCR, 0);
169
170 if (!(priv->irda)) {
171 ark3116_write_reg(serial, 0xb , 0);
172 } else {
173 ark3116_write_reg(serial, 0xb , 1);
174 ark3116_write_reg(serial, 0xc , 0);
175 ark3116_write_reg(serial, 0xd , 0x41);
176 ark3116_write_reg(serial, 0xa , 1);
177 }
178
179 /* setup baudrate */
180 ark3116_write_reg(serial, UART_LCR, UART_LCR_DLAB);
181
182 /* setup for 9600 8N1 */
183 priv->quot = calc_divisor(9600);
184 ark3116_write_reg(serial, UART_DLL, priv->quot & 0xff);
185 ark3116_write_reg(serial, UART_DLM, (priv->quot>>8) & 0xff);
186
187 priv->lcr = UART_LCR_WLEN8;
188 ark3116_write_reg(serial, UART_LCR, UART_LCR_WLEN8);
189
190 ark3116_write_reg(serial, 0xe, 0);
191
192 if (priv->irda)
193 ark3116_write_reg(serial, 0x9, 0);
194
195 dev_info(&serial->dev->dev,
196 "%s using %s mode\n",
197 KBUILD_MODNAME,
198 priv->irda ? "IrDA" : "RS232");
199 return 0;
200}
201
202static void ark3116_release(struct usb_serial *serial)
203{
204 struct usb_serial_port *port = serial->port[0];
205 struct ark3116_private *priv = usb_get_serial_port_data(port);
206
207 /* device is closed, so URBs and DMA should be down */
208
209 usb_set_serial_port_data(port, NULL);
210
211 mutex_destroy(&priv->hw_lock);
212
213 kfree(priv);
214}
215
216static void ark3116_init_termios(struct tty_struct *tty)
217{
218 struct ktermios *termios = tty->termios;
219 *termios = tty_std_termios;
220 termios->c_cflag = B9600 | CS8
221 | CREAD | HUPCL | CLOCAL;
222 termios->c_ispeed = 9600;
223 termios->c_ospeed = 9600;
224}
225
226static void ark3116_set_termios(struct tty_struct *tty,
227 struct usb_serial_port *port,
228 struct ktermios *old_termios)
229{
230 struct usb_serial *serial = port->serial;
231 struct ark3116_private *priv = usb_get_serial_port_data(port);
232 struct ktermios *termios = tty->termios;
233 unsigned int cflag = termios->c_cflag;
234 int bps = tty_get_baud_rate(tty);
235 int quot;
236 __u8 lcr, hcr, eval;
237
238 /* set data bit count */
239 switch (cflag & CSIZE) {
240 case CS5:
241 lcr = UART_LCR_WLEN5;
242 break;
243 case CS6:
244 lcr = UART_LCR_WLEN6;
245 break;
246 case CS7:
247 lcr = UART_LCR_WLEN7;
248 break;
249 default:
250 case CS8:
251 lcr = UART_LCR_WLEN8;
252 break;
253 }
254 if (cflag & CSTOPB)
255 lcr |= UART_LCR_STOP;
256 if (cflag & PARENB)
257 lcr |= UART_LCR_PARITY;
258 if (!(cflag & PARODD))
259 lcr |= UART_LCR_EPAR;
260#ifdef CMSPAR
261 if (cflag & CMSPAR)
262 lcr |= UART_LCR_SPAR;
263#endif
264 /* handshake control */
265 hcr = (cflag & CRTSCTS) ? 0x03 : 0x00;
266
267 /* calc baudrate */
268 dbg("%s - setting bps to %d", __func__, bps);
269 eval = 0;
270 switch (bps) {
271 case 0:
272 quot = calc_divisor(9600);
273 break;
274 default:
275 if ((bps < 75) || (bps > 3000000))
276 bps = 9600;
277 quot = calc_divisor(bps);
278 break;
279 case 460800:
280 eval = 1;
281 quot = calc_divisor(bps);
282 break;
283 case 921600:
284 eval = 2;
285 quot = calc_divisor(bps);
286 break;
287 }
288
289 /* Update state: synchronize */
290 mutex_lock(&priv->hw_lock);
291
292 /* keep old LCR_SBC bit */
293 lcr |= (priv->lcr & UART_LCR_SBC);
294
295 dbg("%s - setting hcr:0x%02x,lcr:0x%02x,quot:%d",
296 __func__, hcr, lcr, quot);
297
298 /* handshake control */
299 if (priv->hcr != hcr) {
300 priv->hcr = hcr;
301 ark3116_write_reg(serial, 0x8, hcr);
302 }
303
304 /* baudrate */
305 if (priv->quot != quot) {
306 priv->quot = quot;
307 priv->lcr = lcr; /* need to write lcr anyway */
308
309 /* disable DMA since transmit/receive is
310 * shadowed by UART_DLL
311 */
312 ark3116_write_reg(serial, UART_FCR, 0);
313
314 ark3116_write_reg(serial, UART_LCR,
315 lcr|UART_LCR_DLAB);
316 ark3116_write_reg(serial, UART_DLL, quot & 0xff);
317 ark3116_write_reg(serial, UART_DLM, (quot>>8) & 0xff);
318
319 /* restore lcr */
320 ark3116_write_reg(serial, UART_LCR, lcr);
321 /* magic baudrate thingy: not sure what it does,
322 * but windows does this as well.
323 */
324 ark3116_write_reg(serial, 0xe, eval);
325
326 /* enable DMA */
327 ark3116_write_reg(serial, UART_FCR, UART_FCR_DMA_SELECT);
328 } else if (priv->lcr != lcr) {
329 priv->lcr = lcr;
330 ark3116_write_reg(serial, UART_LCR, lcr);
331 }
332
333 mutex_unlock(&priv->hw_lock);
334
335 /* check for software flow control */
336 if (I_IXOFF(tty) || I_IXON(tty)) {
337 dev_warn(&serial->dev->dev,
338 "%s: don't know how to do software flow control\n",
339 KBUILD_MODNAME);
340 }
341
342 /* Don't rewrite B0 */
343 if (tty_termios_baud_rate(termios))
344 tty_termios_encode_baud_rate(termios, bps, bps);
345}
346
347static void ark3116_close(struct usb_serial_port *port)
348{
349 struct usb_serial *serial = port->serial;
350
351 if (serial->dev) {
352 /* disable DMA */
353 ark3116_write_reg(serial, UART_FCR, 0);
354
355 /* deactivate interrupts */
356 ark3116_write_reg(serial, UART_IER, 0);
357
358 usb_serial_generic_close(port);
359 if (serial->num_interrupt_in)
360 usb_kill_urb(port->interrupt_in_urb);
361 }
362
363}
364
365static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port)
366{
367 struct ark3116_private *priv = usb_get_serial_port_data(port);
368 struct usb_serial *serial = port->serial;
369 unsigned char *buf;
370 int result;
371
372 buf = kmalloc(1, GFP_KERNEL);
373 if (buf == NULL)
374 return -ENOMEM;
375
376 result = usb_serial_generic_open(tty, port);
377 if (result) {
378 dbg("%s - usb_serial_generic_open failed: %d",
379 __func__, result);
380 goto err_out;
381 }
382
383 /* setup termios */
384 if (tty)
385 ark3116_set_termios(tty, port, NULL);
386
387 /* remove any data still left: also clears error state */
388 ark3116_read_reg(serial, UART_RX, buf);
389
390 /* read modem status */
391 priv->msr = ark3116_read_reg(serial, UART_MSR, buf);
392 /* read line status */
393 priv->lsr = ark3116_read_reg(serial, UART_LSR, buf);
394
395 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
396 if (result) {
397 dev_err(&port->dev, "submit irq_in urb failed %d\n",
398 result);
399 ark3116_close(port);
400 goto err_out;
401 }
402
403 /* activate interrupts */
404 ark3116_write_reg(port->serial, UART_IER, UART_IER_MSI|UART_IER_RLSI);
405
406 /* enable DMA */
407 ark3116_write_reg(port->serial, UART_FCR, UART_FCR_DMA_SELECT);
408
409err_out:
410 kfree(buf);
411 return result;
412}
413
414static int ark3116_get_icount(struct tty_struct *tty,
415 struct serial_icounter_struct *icount)
416{
417 struct usb_serial_port *port = tty->driver_data;
418 struct ark3116_private *priv = usb_get_serial_port_data(port);
419 struct async_icount cnow = priv->icount;
420 icount->cts = cnow.cts;
421 icount->dsr = cnow.dsr;
422 icount->rng = cnow.rng;
423 icount->dcd = cnow.dcd;
424 icount->rx = cnow.rx;
425 icount->tx = cnow.tx;
426 icount->frame = cnow.frame;
427 icount->overrun = cnow.overrun;
428 icount->parity = cnow.parity;
429 icount->brk = cnow.brk;
430 icount->buf_overrun = cnow.buf_overrun;
431 return 0;
432}
433
434static int ark3116_ioctl(struct tty_struct *tty,
435 unsigned int cmd, unsigned long arg)
436{
437 struct usb_serial_port *port = tty->driver_data;
438 struct ark3116_private *priv = usb_get_serial_port_data(port);
439 struct serial_struct serstruct;
440 void __user *user_arg = (void __user *)arg;
441
442 switch (cmd) {
443 case TIOCGSERIAL:
444 /* XXX: Some of these values are probably wrong. */
445 memset(&serstruct, 0, sizeof(serstruct));
446 serstruct.type = PORT_16654;
447 serstruct.line = port->serial->minor;
448 serstruct.port = port->number;
449 serstruct.custom_divisor = 0;
450 serstruct.baud_base = 460800;
451
452 if (copy_to_user(user_arg, &serstruct, sizeof(serstruct)))
453 return -EFAULT;
454
455 return 0;
456 case TIOCSSERIAL:
457 if (copy_from_user(&serstruct, user_arg, sizeof(serstruct)))
458 return -EFAULT;
459 return 0;
460 case TIOCMIWAIT:
461 for (;;) {
462 struct async_icount prev = priv->icount;
463 interruptible_sleep_on(&priv->delta_msr_wait);
464 /* see if a signal did it */
465 if (signal_pending(current))
466 return -ERESTARTSYS;
467 if ((prev.rng == priv->icount.rng) &&
468 (prev.dsr == priv->icount.dsr) &&
469 (prev.dcd == priv->icount.dcd) &&
470 (prev.cts == priv->icount.cts))
471 return -EIO;
472 if ((arg & TIOCM_RNG &&
473 (prev.rng != priv->icount.rng)) ||
474 (arg & TIOCM_DSR &&
475 (prev.dsr != priv->icount.dsr)) ||
476 (arg & TIOCM_CD &&
477 (prev.dcd != priv->icount.dcd)) ||
478 (arg & TIOCM_CTS &&
479 (prev.cts != priv->icount.cts)))
480 return 0;
481 }
482 break;
483 }
484
485 return -ENOIOCTLCMD;
486}
487
488static int ark3116_tiocmget(struct tty_struct *tty)
489{
490 struct usb_serial_port *port = tty->driver_data;
491 struct ark3116_private *priv = usb_get_serial_port_data(port);
492 __u32 status;
493 __u32 ctrl;
494 unsigned long flags;
495
496 mutex_lock(&priv->hw_lock);
497 ctrl = priv->mcr;
498 mutex_unlock(&priv->hw_lock);
499
500 spin_lock_irqsave(&priv->status_lock, flags);
501 status = priv->msr;
502 spin_unlock_irqrestore(&priv->status_lock, flags);
503
504 return (status & UART_MSR_DSR ? TIOCM_DSR : 0) |
505 (status & UART_MSR_CTS ? TIOCM_CTS : 0) |
506 (status & UART_MSR_RI ? TIOCM_RI : 0) |
507 (status & UART_MSR_DCD ? TIOCM_CD : 0) |
508 (ctrl & UART_MCR_DTR ? TIOCM_DTR : 0) |
509 (ctrl & UART_MCR_RTS ? TIOCM_RTS : 0) |
510 (ctrl & UART_MCR_OUT1 ? TIOCM_OUT1 : 0) |
511 (ctrl & UART_MCR_OUT2 ? TIOCM_OUT2 : 0);
512}
513
514static int ark3116_tiocmset(struct tty_struct *tty,
515 unsigned set, unsigned clr)
516{
517 struct usb_serial_port *port = tty->driver_data;
518 struct ark3116_private *priv = usb_get_serial_port_data(port);
519
520 /* we need to take the mutex here, to make sure that the value
521 * in priv->mcr is actually the one that is in the hardware
522 */
523
524 mutex_lock(&priv->hw_lock);
525
526 if (set & TIOCM_RTS)
527 priv->mcr |= UART_MCR_RTS;
528 if (set & TIOCM_DTR)
529 priv->mcr |= UART_MCR_DTR;
530 if (set & TIOCM_OUT1)
531 priv->mcr |= UART_MCR_OUT1;
532 if (set & TIOCM_OUT2)
533 priv->mcr |= UART_MCR_OUT2;
534 if (clr & TIOCM_RTS)
535 priv->mcr &= ~UART_MCR_RTS;
536 if (clr & TIOCM_DTR)
537 priv->mcr &= ~UART_MCR_DTR;
538 if (clr & TIOCM_OUT1)
539 priv->mcr &= ~UART_MCR_OUT1;
540 if (clr & TIOCM_OUT2)
541 priv->mcr &= ~UART_MCR_OUT2;
542
543 ark3116_write_reg(port->serial, UART_MCR, priv->mcr);
544
545 mutex_unlock(&priv->hw_lock);
546
547 return 0;
548}
549
550static void ark3116_break_ctl(struct tty_struct *tty, int break_state)
551{
552 struct usb_serial_port *port = tty->driver_data;
553 struct ark3116_private *priv = usb_get_serial_port_data(port);
554
555 /* LCR is also used for other things: protect access */
556 mutex_lock(&priv->hw_lock);
557
558 if (break_state)
559 priv->lcr |= UART_LCR_SBC;
560 else
561 priv->lcr &= ~UART_LCR_SBC;
562
563 ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
564
565 mutex_unlock(&priv->hw_lock);
566}
567
568static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
569{
570 struct ark3116_private *priv = usb_get_serial_port_data(port);
571 unsigned long flags;
572
573 spin_lock_irqsave(&priv->status_lock, flags);
574 priv->msr = msr;
575 spin_unlock_irqrestore(&priv->status_lock, flags);
576
577 if (msr & UART_MSR_ANY_DELTA) {
578 /* update input line counters */
579 if (msr & UART_MSR_DCTS)
580 priv->icount.cts++;
581 if (msr & UART_MSR_DDSR)
582 priv->icount.dsr++;
583 if (msr & UART_MSR_DDCD)
584 priv->icount.dcd++;
585 if (msr & UART_MSR_TERI)
586 priv->icount.rng++;
587 wake_up_interruptible(&priv->delta_msr_wait);
588 }
589}
590
591static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr)
592{
593 struct ark3116_private *priv = usb_get_serial_port_data(port);
594 unsigned long flags;
595
596 spin_lock_irqsave(&priv->status_lock, flags);
597 /* combine bits */
598 priv->lsr |= lsr;
599 spin_unlock_irqrestore(&priv->status_lock, flags);
600
601 if (lsr&UART_LSR_BRK_ERROR_BITS) {
602 if (lsr & UART_LSR_BI)
603 priv->icount.brk++;
604 if (lsr & UART_LSR_FE)
605 priv->icount.frame++;
606 if (lsr & UART_LSR_PE)
607 priv->icount.parity++;
608 if (lsr & UART_LSR_OE)
609 priv->icount.overrun++;
610 }
611}
612
613static void ark3116_read_int_callback(struct urb *urb)
614{
615 struct usb_serial_port *port = urb->context;
616 int status = urb->status;
617 const __u8 *data = urb->transfer_buffer;
618 int result;
619
620 switch (status) {
621 case -ECONNRESET:
622 case -ENOENT:
623 case -ESHUTDOWN:
624 /* this urb is terminated, clean up */
625 dbg("%s - urb shutting down with status: %d",
626 __func__, status);
627 return;
628 default:
629 dbg("%s - nonzero urb status received: %d",
630 __func__, status);
631 break;
632 case 0: /* success */
633 /* discovered this by trail and error... */
634 if ((urb->actual_length == 4) && (data[0] == 0xe8)) {
635 const __u8 id = data[1]&UART_IIR_ID;
636 dbg("%s: iir=%02x", __func__, data[1]);
637 if (id == UART_IIR_MSI) {
638 dbg("%s: msr=%02x", __func__, data[3]);
639 ark3116_update_msr(port, data[3]);
640 break;
641 } else if (id == UART_IIR_RLSI) {
642 dbg("%s: lsr=%02x", __func__, data[2]);
643 ark3116_update_lsr(port, data[2]);
644 break;
645 }
646 }
647 /*
648 * Not sure what this data meant...
649 */
650 usb_serial_debug_data(debug, &port->dev,
651 __func__,
652 urb->actual_length,
653 urb->transfer_buffer);
654 break;
655 }
656
657 result = usb_submit_urb(urb, GFP_ATOMIC);
658 if (result)
659 dev_err(&urb->dev->dev,
660 "%s - Error %d submitting interrupt urb\n",
661 __func__, result);
662}
663
664
665/* Data comes in via the bulk (data) URB, erors/interrupts via the int URB.
666 * This means that we cannot be sure which data byte has an associated error
667 * condition, so we report an error for all data in the next bulk read.
668 *
669 * Actually, there might even be a window between the bulk data leaving the
670 * ark and reading/resetting the lsr in the read_bulk_callback where an
671 * interrupt for the next data block could come in.
672 * Without somekind of ordering on the ark, we would have to report the
673 * error for the next block of data as well...
674 * For now, let's pretend this can't happen.
675 */
676static void ark3116_process_read_urb(struct urb *urb)
677{
678 struct usb_serial_port *port = urb->context;
679 struct ark3116_private *priv = usb_get_serial_port_data(port);
680 struct tty_struct *tty;
681 unsigned char *data = urb->transfer_buffer;
682 char tty_flag = TTY_NORMAL;
683 unsigned long flags;
684 __u32 lsr;
685
686 /* update line status */
687 spin_lock_irqsave(&priv->status_lock, flags);
688 lsr = priv->lsr;
689 priv->lsr &= ~UART_LSR_BRK_ERROR_BITS;
690 spin_unlock_irqrestore(&priv->status_lock, flags);
691
692 if (!urb->actual_length)
693 return;
694
695 tty = tty_port_tty_get(&port->port);
696 if (!tty)
697 return;
698
699 if (lsr & UART_LSR_BRK_ERROR_BITS) {
700 if (lsr & UART_LSR_BI)
701 tty_flag = TTY_BREAK;
702 else if (lsr & UART_LSR_PE)
703 tty_flag = TTY_PARITY;
704 else if (lsr & UART_LSR_FE)
705 tty_flag = TTY_FRAME;
706
707 /* overrun is special, not associated with a char */
708 if (lsr & UART_LSR_OE)
709 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
710 }
711 tty_insert_flip_string_fixed_flag(tty, data, tty_flag,
712 urb->actual_length);
713 tty_flip_buffer_push(tty);
714 tty_kref_put(tty);
715}
716
717static struct usb_driver ark3116_driver = {
718 .name = "ark3116",
719 .probe = usb_serial_probe,
720 .disconnect = usb_serial_disconnect,
721 .id_table = id_table,
722 .no_dynamic_id = 1,
723};
724
725static struct usb_serial_driver ark3116_device = {
726 .driver = {
727 .owner = THIS_MODULE,
728 .name = "ark3116",
729 },
730 .id_table = id_table,
731 .usb_driver = &ark3116_driver,
732 .num_ports = 1,
733 .attach = ark3116_attach,
734 .release = ark3116_release,
735 .set_termios = ark3116_set_termios,
736 .init_termios = ark3116_init_termios,
737 .ioctl = ark3116_ioctl,
738 .tiocmget = ark3116_tiocmget,
739 .tiocmset = ark3116_tiocmset,
740 .get_icount = ark3116_get_icount,
741 .open = ark3116_open,
742 .close = ark3116_close,
743 .break_ctl = ark3116_break_ctl,
744 .read_int_callback = ark3116_read_int_callback,
745 .process_read_urb = ark3116_process_read_urb,
746};
747
748static int __init ark3116_init(void)
749{
750 int retval;
751
752 retval = usb_serial_register(&ark3116_device);
753 if (retval)
754 return retval;
755 retval = usb_register(&ark3116_driver);
756 if (retval == 0) {
757 printk(KERN_INFO "%s:"
758 DRIVER_VERSION ":"
759 DRIVER_DESC "\n",
760 KBUILD_MODNAME);
761 } else
762 usb_serial_deregister(&ark3116_device);
763 return retval;
764}
765
766static void __exit ark3116_exit(void)
767{
768 usb_deregister(&ark3116_driver);
769 usb_serial_deregister(&ark3116_device);
770}
771
772module_init(ark3116_init);
773module_exit(ark3116_exit);
774MODULE_LICENSE("GPL");
775
776MODULE_AUTHOR(DRIVER_AUTHOR);
777MODULE_DESCRIPTION(DRIVER_DESC);
778
779module_param(debug, bool, S_IRUGO | S_IWUSR);
780MODULE_PARM_DESC(debug, "Enable debug");
781
782/*
783 * The following describes what I learned from studying the old
784 * ark3116.c driver, disassembling the windows driver, and some lucky
785 * guesses. Since I do not have any datasheet or other
786 * documentation, inaccuracies are almost guaranteed.
787 *
788 * Some specs for the ARK3116 can be found here:
789 * http://web.archive.org/web/20060318000438/
790 * www.arkmicro.com/en/products/view.php?id=10
791 * On that page, 2 GPIO pins are mentioned: I assume these are the
792 * OUT1 and OUT2 pins of the UART, so I added support for those
793 * through the MCR. Since the pins are not available on my hardware,
794 * I could not verify this.
795 * Also, it states there is "on-chip hardware flow control". I have
796 * discovered how to enable that. Unfortunately, I do not know how to
797 * enable XON/XOFF (software) flow control, which would need support
798 * from the chip as well to work. Because of the wording on the web
799 * page there is a real possibility the chip simply does not support
800 * software flow control.
801 *
802 * I got my ark3116 as part of a mobile phone adapter cable. On the
803 * PCB, the following numbered contacts are present:
804 *
805 * 1:- +5V
806 * 2:o DTR
807 * 3:i RX
808 * 4:i DCD
809 * 5:o RTS
810 * 6:o TX
811 * 7:i RI
812 * 8:i DSR
813 * 10:- 0V
814 * 11:i CTS
815 *
816 * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that
817 * may be different for the one you have ;-).
818 *
819 * The windows driver limits the registers to 0-F, so I assume there
820 * are actually 16 present on the device.
821 *
822 * On an UART interrupt, 4 bytes of data come in on the interrupt
823 * endpoint. The bytes are 0xe8 IIR LSR MSR.
824 *
825 * The baudrate seems to be generated from the 12MHz crystal, using
826 * 4-times subsampling. So quot=12e6/(4*baud). Also see description
827 * of register E.
828 *
829 * Registers 0-7:
830 * These seem to be the same as for a regular 16450. The FCR is set
831 * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between
832 * the UART and the USB bridge/DMA engine.
833 *
834 * Register 8:
835 * By trial and error, I found out that bit 0 enables hardware CTS,
836 * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making
837 * RTS +5V when the 3116 cannot transfer the data to the USB bus
838 * (verified by disabling the reading URB). Note that as far as I can
839 * tell, the windows driver does NOT use this, so there might be some
840 * hardware bug or something.
841 *
842 * According to a patch provided here
843 * (http://lkml.org/lkml/2009/7/26/56), the ARK3116 can also be used
844 * as an IrDA dongle. Since I do not have such a thing, I could not
845 * investigate that aspect. However, I can speculate ;-).
846 *
847 * - IrDA encodes data differently than RS232. Most likely, one of
848 * the bits in registers 9..E enables the IR ENDEC (encoder/decoder).
849 * - Depending on the IR transceiver, the input and output need to be
850 * inverted, so there are probably bits for that as well.
851 * - IrDA is half-duplex, so there should be a bit for selecting that.
852 *
853 * This still leaves at least two registers unaccounted for. Perhaps
854 * The chip can do XON/XOFF or CRC in HW?
855 *
856 * Register 9:
857 * Set to 0x00 for IrDA, when the baudrate is initialised.
858 *
859 * Register A:
860 * Set to 0x01 for IrDA, at init.
861 *
862 * Register B:
863 * Set to 0x01 for IrDA, 0x00 for RS232, at init.
864 *
865 * Register C:
866 * Set to 00 for IrDA, at init.
867 *
868 * Register D:
869 * Set to 0x41 for IrDA, at init.
870 *
871 * Register E:
872 * Somekind of baudrate override. The windows driver seems to set
873 * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600.
874 * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer,
875 * it could be somekind of subdivisor thingy.
876 * However,it does not seem to do anything: selecting 921600 (divisor 3,
877 * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would
878 * work, but they don't.
879 *
880 * Register F: unknown
881 */
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 void 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
190static void ark3116_set_termios(struct tty_struct *tty,
191 struct usb_serial_port *port,
192 const struct ktermios *old_termios)
193{
194 struct usb_serial *serial = port->serial;
195 struct ark3116_private *priv = usb_get_serial_port_data(port);
196 struct ktermios *termios = &tty->termios;
197 unsigned int cflag = termios->c_cflag;
198 int bps = tty_get_baud_rate(tty);
199 int quot;
200 __u8 lcr, hcr, eval;
201
202 /* set data bit count */
203 lcr = UART_LCR_WLEN(tty_get_char_size(cflag));
204
205 if (cflag & CSTOPB)
206 lcr |= UART_LCR_STOP;
207 if (cflag & PARENB)
208 lcr |= UART_LCR_PARITY;
209 if (!(cflag & PARODD))
210 lcr |= UART_LCR_EPAR;
211 if (cflag & CMSPAR)
212 lcr |= UART_LCR_SPAR;
213
214 /* handshake control */
215 hcr = (cflag & CRTSCTS) ? 0x03 : 0x00;
216
217 /* calc baudrate */
218 dev_dbg(&port->dev, "%s - setting bps to %d\n", __func__, bps);
219 eval = 0;
220 switch (bps) {
221 case 0:
222 quot = calc_divisor(9600);
223 break;
224 default:
225 if ((bps < 75) || (bps > 3000000))
226 bps = 9600;
227 quot = calc_divisor(bps);
228 break;
229 case 460800:
230 eval = 1;
231 quot = calc_divisor(bps);
232 break;
233 case 921600:
234 eval = 2;
235 quot = calc_divisor(bps);
236 break;
237 }
238
239 /* Update state: synchronize */
240 mutex_lock(&priv->hw_lock);
241
242 /* keep old LCR_SBC bit */
243 lcr |= (priv->lcr & UART_LCR_SBC);
244
245 dev_dbg(&port->dev, "%s - setting hcr:0x%02x,lcr:0x%02x,quot:%d\n",
246 __func__, hcr, lcr, quot);
247
248 /* handshake control */
249 if (priv->hcr != hcr) {
250 priv->hcr = hcr;
251 ark3116_write_reg(serial, 0x8, hcr);
252 }
253
254 /* baudrate */
255 if (priv->quot != quot) {
256 priv->quot = quot;
257 priv->lcr = lcr; /* need to write lcr anyway */
258
259 /* disable DMA since transmit/receive is
260 * shadowed by UART_DLL
261 */
262 ark3116_write_reg(serial, UART_FCR, 0);
263
264 ark3116_write_reg(serial, UART_LCR,
265 lcr|UART_LCR_DLAB);
266 ark3116_write_reg(serial, UART_DLL, quot & 0xff);
267 ark3116_write_reg(serial, UART_DLM, (quot>>8) & 0xff);
268
269 /* restore lcr */
270 ark3116_write_reg(serial, UART_LCR, lcr);
271 /* magic baudrate thingy: not sure what it does,
272 * but windows does this as well.
273 */
274 ark3116_write_reg(serial, 0xe, eval);
275
276 /* enable DMA */
277 ark3116_write_reg(serial, UART_FCR, UART_FCR_DMA_SELECT);
278 } else if (priv->lcr != lcr) {
279 priv->lcr = lcr;
280 ark3116_write_reg(serial, UART_LCR, lcr);
281 }
282
283 mutex_unlock(&priv->hw_lock);
284
285 /* check for software flow control */
286 if (I_IXOFF(tty) || I_IXON(tty)) {
287 dev_warn(&port->dev,
288 "software flow control not implemented\n");
289 }
290
291 /* Don't rewrite B0 */
292 if (tty_termios_baud_rate(termios))
293 tty_termios_encode_baud_rate(termios, bps, bps);
294}
295
296static void ark3116_close(struct usb_serial_port *port)
297{
298 struct usb_serial *serial = port->serial;
299
300 /* disable DMA */
301 ark3116_write_reg(serial, UART_FCR, 0);
302
303 /* deactivate interrupts */
304 ark3116_write_reg(serial, UART_IER, 0);
305
306 usb_serial_generic_close(port);
307
308 usb_kill_urb(port->interrupt_in_urb);
309}
310
311static int ark3116_open(struct tty_struct *tty, struct usb_serial_port *port)
312{
313 struct ark3116_private *priv = usb_get_serial_port_data(port);
314 struct usb_serial *serial = port->serial;
315 unsigned char *buf;
316 int result;
317
318 buf = kmalloc(1, GFP_KERNEL);
319 if (buf == NULL)
320 return -ENOMEM;
321
322 result = usb_serial_generic_open(tty, port);
323 if (result) {
324 dev_dbg(&port->dev,
325 "%s - usb_serial_generic_open failed: %d\n",
326 __func__, result);
327 goto err_free;
328 }
329
330 /* remove any data still left: also clears error state */
331 ark3116_read_reg(serial, UART_RX, buf);
332
333 /* read modem status */
334 result = ark3116_read_reg(serial, UART_MSR, buf);
335 if (result)
336 goto err_close;
337 priv->msr = *buf;
338
339 /* read line status */
340 result = ark3116_read_reg(serial, UART_LSR, buf);
341 if (result)
342 goto err_close;
343 priv->lsr = *buf;
344
345 result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
346 if (result) {
347 dev_err(&port->dev, "submit irq_in urb failed %d\n",
348 result);
349 goto err_close;
350 }
351
352 /* activate interrupts */
353 ark3116_write_reg(port->serial, UART_IER, UART_IER_MSI|UART_IER_RLSI);
354
355 /* enable DMA */
356 ark3116_write_reg(port->serial, UART_FCR, UART_FCR_DMA_SELECT);
357
358 /* setup termios */
359 if (tty)
360 ark3116_set_termios(tty, port, NULL);
361
362 kfree(buf);
363
364 return 0;
365
366err_close:
367 usb_serial_generic_close(port);
368err_free:
369 kfree(buf);
370
371 return result;
372}
373
374static int ark3116_tiocmget(struct tty_struct *tty)
375{
376 struct usb_serial_port *port = tty->driver_data;
377 struct ark3116_private *priv = usb_get_serial_port_data(port);
378 __u32 status;
379 __u32 ctrl;
380 unsigned long flags;
381
382 mutex_lock(&priv->hw_lock);
383 ctrl = priv->mcr;
384 mutex_unlock(&priv->hw_lock);
385
386 spin_lock_irqsave(&priv->status_lock, flags);
387 status = priv->msr;
388 spin_unlock_irqrestore(&priv->status_lock, flags);
389
390 return (status & UART_MSR_DSR ? TIOCM_DSR : 0) |
391 (status & UART_MSR_CTS ? TIOCM_CTS : 0) |
392 (status & UART_MSR_RI ? TIOCM_RI : 0) |
393 (status & UART_MSR_DCD ? TIOCM_CD : 0) |
394 (ctrl & UART_MCR_DTR ? TIOCM_DTR : 0) |
395 (ctrl & UART_MCR_RTS ? TIOCM_RTS : 0) |
396 (ctrl & UART_MCR_OUT1 ? TIOCM_OUT1 : 0) |
397 (ctrl & UART_MCR_OUT2 ? TIOCM_OUT2 : 0);
398}
399
400static int ark3116_tiocmset(struct tty_struct *tty,
401 unsigned set, unsigned clr)
402{
403 struct usb_serial_port *port = tty->driver_data;
404 struct ark3116_private *priv = usb_get_serial_port_data(port);
405
406 /* we need to take the mutex here, to make sure that the value
407 * in priv->mcr is actually the one that is in the hardware
408 */
409
410 mutex_lock(&priv->hw_lock);
411
412 if (set & TIOCM_RTS)
413 priv->mcr |= UART_MCR_RTS;
414 if (set & TIOCM_DTR)
415 priv->mcr |= UART_MCR_DTR;
416 if (set & TIOCM_OUT1)
417 priv->mcr |= UART_MCR_OUT1;
418 if (set & TIOCM_OUT2)
419 priv->mcr |= UART_MCR_OUT2;
420 if (clr & TIOCM_RTS)
421 priv->mcr &= ~UART_MCR_RTS;
422 if (clr & TIOCM_DTR)
423 priv->mcr &= ~UART_MCR_DTR;
424 if (clr & TIOCM_OUT1)
425 priv->mcr &= ~UART_MCR_OUT1;
426 if (clr & TIOCM_OUT2)
427 priv->mcr &= ~UART_MCR_OUT2;
428
429 ark3116_write_reg(port->serial, UART_MCR, priv->mcr);
430
431 mutex_unlock(&priv->hw_lock);
432
433 return 0;
434}
435
436static int ark3116_break_ctl(struct tty_struct *tty, int break_state)
437{
438 struct usb_serial_port *port = tty->driver_data;
439 struct ark3116_private *priv = usb_get_serial_port_data(port);
440 int ret;
441
442 /* LCR is also used for other things: protect access */
443 mutex_lock(&priv->hw_lock);
444
445 if (break_state)
446 priv->lcr |= UART_LCR_SBC;
447 else
448 priv->lcr &= ~UART_LCR_SBC;
449
450 ret = ark3116_write_reg(port->serial, UART_LCR, priv->lcr);
451
452 mutex_unlock(&priv->hw_lock);
453
454 return ret;
455}
456
457static void ark3116_update_msr(struct usb_serial_port *port, __u8 msr)
458{
459 struct ark3116_private *priv = usb_get_serial_port_data(port);
460 unsigned long flags;
461
462 spin_lock_irqsave(&priv->status_lock, flags);
463 priv->msr = msr;
464 spin_unlock_irqrestore(&priv->status_lock, flags);
465
466 if (msr & UART_MSR_ANY_DELTA) {
467 /* update input line counters */
468 if (msr & UART_MSR_DCTS)
469 port->icount.cts++;
470 if (msr & UART_MSR_DDSR)
471 port->icount.dsr++;
472 if (msr & UART_MSR_DDCD)
473 port->icount.dcd++;
474 if (msr & UART_MSR_TERI)
475 port->icount.rng++;
476 wake_up_interruptible(&port->port.delta_msr_wait);
477 }
478}
479
480static void ark3116_update_lsr(struct usb_serial_port *port, __u8 lsr)
481{
482 struct ark3116_private *priv = usb_get_serial_port_data(port);
483 unsigned long flags;
484
485 spin_lock_irqsave(&priv->status_lock, flags);
486 /* combine bits */
487 priv->lsr |= lsr;
488 spin_unlock_irqrestore(&priv->status_lock, flags);
489
490 if (lsr&UART_LSR_BRK_ERROR_BITS) {
491 if (lsr & UART_LSR_BI)
492 port->icount.brk++;
493 if (lsr & UART_LSR_FE)
494 port->icount.frame++;
495 if (lsr & UART_LSR_PE)
496 port->icount.parity++;
497 if (lsr & UART_LSR_OE)
498 port->icount.overrun++;
499 }
500}
501
502static void ark3116_read_int_callback(struct urb *urb)
503{
504 struct usb_serial_port *port = urb->context;
505 int status = urb->status;
506 const __u8 *data = urb->transfer_buffer;
507 int result;
508
509 switch (status) {
510 case -ECONNRESET:
511 case -ENOENT:
512 case -ESHUTDOWN:
513 /* this urb is terminated, clean up */
514 dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
515 __func__, status);
516 return;
517 default:
518 dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
519 __func__, status);
520 break;
521 case 0: /* success */
522 /* discovered this by trail and error... */
523 if ((urb->actual_length == 4) && (data[0] == 0xe8)) {
524 const __u8 id = data[1]&UART_IIR_ID;
525 dev_dbg(&port->dev, "%s: iir=%02x\n", __func__, data[1]);
526 if (id == UART_IIR_MSI) {
527 dev_dbg(&port->dev, "%s: msr=%02x\n",
528 __func__, data[3]);
529 ark3116_update_msr(port, data[3]);
530 break;
531 } else if (id == UART_IIR_RLSI) {
532 dev_dbg(&port->dev, "%s: lsr=%02x\n",
533 __func__, data[2]);
534 ark3116_update_lsr(port, data[2]);
535 break;
536 }
537 }
538 /*
539 * Not sure what this data meant...
540 */
541 usb_serial_debug_data(&port->dev, __func__,
542 urb->actual_length,
543 urb->transfer_buffer);
544 break;
545 }
546
547 result = usb_submit_urb(urb, GFP_ATOMIC);
548 if (result)
549 dev_err(&port->dev, "failed to resubmit interrupt urb: %d\n",
550 result);
551}
552
553
554/* Data comes in via the bulk (data) URB, errors/interrupts via the int URB.
555 * This means that we cannot be sure which data byte has an associated error
556 * condition, so we report an error for all data in the next bulk read.
557 *
558 * Actually, there might even be a window between the bulk data leaving the
559 * ark and reading/resetting the lsr in the read_bulk_callback where an
560 * interrupt for the next data block could come in.
561 * Without somekind of ordering on the ark, we would have to report the
562 * error for the next block of data as well...
563 * For now, let's pretend this can't happen.
564 */
565static void ark3116_process_read_urb(struct urb *urb)
566{
567 struct usb_serial_port *port = urb->context;
568 struct ark3116_private *priv = usb_get_serial_port_data(port);
569 unsigned char *data = urb->transfer_buffer;
570 char tty_flag = TTY_NORMAL;
571 unsigned long flags;
572 __u32 lsr;
573
574 /* update line status */
575 spin_lock_irqsave(&priv->status_lock, flags);
576 lsr = priv->lsr;
577 priv->lsr &= ~UART_LSR_BRK_ERROR_BITS;
578 spin_unlock_irqrestore(&priv->status_lock, flags);
579
580 if (!urb->actual_length)
581 return;
582
583 if (lsr & UART_LSR_BRK_ERROR_BITS) {
584 if (lsr & UART_LSR_BI)
585 tty_flag = TTY_BREAK;
586 else if (lsr & UART_LSR_PE)
587 tty_flag = TTY_PARITY;
588 else if (lsr & UART_LSR_FE)
589 tty_flag = TTY_FRAME;
590
591 /* overrun is special, not associated with a char */
592 if (lsr & UART_LSR_OE)
593 tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
594 }
595 tty_insert_flip_string_fixed_flag(&port->port, data, tty_flag,
596 urb->actual_length);
597 tty_flip_buffer_push(&port->port);
598}
599
600static struct usb_serial_driver ark3116_device = {
601 .driver = {
602 .owner = THIS_MODULE,
603 .name = "ark3116",
604 },
605 .id_table = id_table,
606 .num_ports = 1,
607 .num_bulk_in = 1,
608 .num_bulk_out = 1,
609 .num_interrupt_in = 1,
610 .port_probe = ark3116_port_probe,
611 .port_remove = ark3116_port_remove,
612 .set_termios = ark3116_set_termios,
613 .tiocmget = ark3116_tiocmget,
614 .tiocmset = ark3116_tiocmset,
615 .tiocmiwait = usb_serial_generic_tiocmiwait,
616 .get_icount = usb_serial_generic_get_icount,
617 .open = ark3116_open,
618 .close = ark3116_close,
619 .break_ctl = ark3116_break_ctl,
620 .read_int_callback = ark3116_read_int_callback,
621 .process_read_urb = ark3116_process_read_urb,
622};
623
624static struct usb_serial_driver * const serial_drivers[] = {
625 &ark3116_device, NULL
626};
627
628module_usb_serial_driver(serial_drivers, id_table);
629
630MODULE_LICENSE("GPL");
631
632MODULE_AUTHOR(DRIVER_AUTHOR);
633MODULE_DESCRIPTION(DRIVER_DESC);
634
635/*
636 * The following describes what I learned from studying the old
637 * ark3116.c driver, disassembling the windows driver, and some lucky
638 * guesses. Since I do not have any datasheet or other
639 * documentation, inaccuracies are almost guaranteed.
640 *
641 * Some specs for the ARK3116 can be found here:
642 * http://web.archive.org/web/20060318000438/
643 * www.arkmicro.com/en/products/view.php?id=10
644 * On that page, 2 GPIO pins are mentioned: I assume these are the
645 * OUT1 and OUT2 pins of the UART, so I added support for those
646 * through the MCR. Since the pins are not available on my hardware,
647 * I could not verify this.
648 * Also, it states there is "on-chip hardware flow control". I have
649 * discovered how to enable that. Unfortunately, I do not know how to
650 * enable XON/XOFF (software) flow control, which would need support
651 * from the chip as well to work. Because of the wording on the web
652 * page there is a real possibility the chip simply does not support
653 * software flow control.
654 *
655 * I got my ark3116 as part of a mobile phone adapter cable. On the
656 * PCB, the following numbered contacts are present:
657 *
658 * 1:- +5V
659 * 2:o DTR
660 * 3:i RX
661 * 4:i DCD
662 * 5:o RTS
663 * 6:o TX
664 * 7:i RI
665 * 8:i DSR
666 * 10:- 0V
667 * 11:i CTS
668 *
669 * On my chip, all signals seem to be 3.3V, but 5V tolerant. But that
670 * may be different for the one you have ;-).
671 *
672 * The windows driver limits the registers to 0-F, so I assume there
673 * are actually 16 present on the device.
674 *
675 * On an UART interrupt, 4 bytes of data come in on the interrupt
676 * endpoint. The bytes are 0xe8 IIR LSR MSR.
677 *
678 * The baudrate seems to be generated from the 12MHz crystal, using
679 * 4-times subsampling. So quot=12e6/(4*baud). Also see description
680 * of register E.
681 *
682 * Registers 0-7:
683 * These seem to be the same as for a regular 16450. The FCR is set
684 * to UART_FCR_DMA_SELECT (0x8), I guess to enable transfers between
685 * the UART and the USB bridge/DMA engine.
686 *
687 * Register 8:
688 * By trial and error, I found out that bit 0 enables hardware CTS,
689 * stopping TX when CTS is +5V. Bit 1 does the same for RTS, making
690 * RTS +5V when the 3116 cannot transfer the data to the USB bus
691 * (verified by disabling the reading URB). Note that as far as I can
692 * tell, the windows driver does NOT use this, so there might be some
693 * hardware bug or something.
694 *
695 * According to a patch provided here
696 * https://lore.kernel.org/lkml/200907261419.50702.linux@rainbow-software.org
697 * the ARK3116 can also be used as an IrDA dongle. Since I do not have
698 * such a thing, I could not investigate that aspect. However, I can
699 * speculate ;-).
700 *
701 * - IrDA encodes data differently than RS232. Most likely, one of
702 * the bits in registers 9..E enables the IR ENDEC (encoder/decoder).
703 * - Depending on the IR transceiver, the input and output need to be
704 * inverted, so there are probably bits for that as well.
705 * - IrDA is half-duplex, so there should be a bit for selecting that.
706 *
707 * This still leaves at least two registers unaccounted for. Perhaps
708 * The chip can do XON/XOFF or CRC in HW?
709 *
710 * Register 9:
711 * Set to 0x00 for IrDA, when the baudrate is initialised.
712 *
713 * Register A:
714 * Set to 0x01 for IrDA, at init.
715 *
716 * Register B:
717 * Set to 0x01 for IrDA, 0x00 for RS232, at init.
718 *
719 * Register C:
720 * Set to 00 for IrDA, at init.
721 *
722 * Register D:
723 * Set to 0x41 for IrDA, at init.
724 *
725 * Register E:
726 * Somekind of baudrate override. The windows driver seems to set
727 * this to 0x00 for normal baudrates, 0x01 for 460800, 0x02 for 921600.
728 * Since 460800 and 921600 cannot be obtained by dividing 3MHz by an integer,
729 * it could be somekind of subdivisor thingy.
730 * However,it does not seem to do anything: selecting 921600 (divisor 3,
731 * reg E=2), still gets 1 MHz. I also checked if registers 9, C or F would
732 * work, but they don't.
733 *
734 * Register F: unknown
735 */