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