aboutsummaryrefslogtreecommitdiff
path: root/drivers/usb/serial/f81232.c
blob: 972f5a5fe577ed31686bda9cedfc75313e5ce1f1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
/*
 * Fintek F81232 USB to serial adaptor driver
 *
 * Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
 * Copyright (C) 2012 Linux Foundation
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial_reg.h>

static const struct usb_device_id id_table[] = {
	{ USB_DEVICE(0x1934, 0x0706) },
	{ }					/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);

/* Maximum baudrate for F81232 */
#define F81232_MAX_BAUDRATE		115200

/* USB Control EP parameter */
#define F81232_REGISTER_REQUEST		0xa0
#define F81232_GET_REGISTER		0xc0
#define F81232_SET_REGISTER		0x40

#define SERIAL_BASE_ADDRESS		0x0120
#define RECEIVE_BUFFER_REGISTER		(0x00 + SERIAL_BASE_ADDRESS)
#define INTERRUPT_ENABLE_REGISTER	(0x01 + SERIAL_BASE_ADDRESS)
#define FIFO_CONTROL_REGISTER		(0x02 + SERIAL_BASE_ADDRESS)
#define LINE_CONTROL_REGISTER		(0x03 + SERIAL_BASE_ADDRESS)
#define MODEM_CONTROL_REGISTER		(0x04 + SERIAL_BASE_ADDRESS)
#define MODEM_STATUS_REGISTER		(0x06 + SERIAL_BASE_ADDRESS)

struct f81232_private {
	struct mutex lock;
	u8 modem_control;
	u8 modem_status;
	struct work_struct interrupt_work;
	struct usb_serial_port *port;
};

static int calc_baud_divisor(speed_t baudrate)
{
	return DIV_ROUND_CLOSEST(F81232_MAX_BAUDRATE, baudrate);
}

static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
{
	int status;
	u8 *tmp;
	struct usb_device *dev = port->serial->dev;

	tmp = kmalloc(sizeof(*val), GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	status = usb_control_msg(dev,
				usb_rcvctrlpipe(dev, 0),
				F81232_REGISTER_REQUEST,
				F81232_GET_REGISTER,
				reg,
				0,
				tmp,
				sizeof(*val),
				USB_CTRL_GET_TIMEOUT);
	if (status != sizeof(*val)) {
		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);

		if (status < 0)
			status = usb_translate_errors(status);
		else
			status = -EIO;
	} else {
		status = 0;
		*val = *tmp;
	}

	kfree(tmp);
	return status;
}

static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
{
	int status;
	u8 *tmp;
	struct usb_device *dev = port->serial->dev;

	tmp = kmalloc(sizeof(val), GFP_KERNEL);
	if (!tmp)
		return -ENOMEM;

	*tmp = val;

	status = usb_control_msg(dev,
				usb_sndctrlpipe(dev, 0),
				F81232_REGISTER_REQUEST,
				F81232_SET_REGISTER,
				reg,
				0,
				tmp,
				sizeof(val),
				USB_CTRL_SET_TIMEOUT);
	if (status != sizeof(val)) {
		dev_err(&port->dev, "%s failed status: %d\n", __func__, status);

		if (status < 0)
			status = usb_translate_errors(status);
		else
			status = -EIO;
	} else {
		status = 0;
	}

	kfree(tmp);
	return status;
}

static void f81232_read_msr(struct usb_serial_port *port)
{
	int status;
	u8 current_msr;
	struct tty_struct *tty;
	struct f81232_private *priv = usb_get_serial_port_data(port);

	mutex_lock(&priv->lock);
	status = f81232_get_register(port, MODEM_STATUS_REGISTER,
			&current_msr);
	if (status) {
		dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
		mutex_unlock(&priv->lock);
		return;
	}

	if (!(current_msr & UART_MSR_ANY_DELTA)) {
		mutex_unlock(&priv->lock);
		return;
	}

	priv->modem_status = current_msr;

	if (current_msr & UART_MSR_DCTS)
		port->icount.cts++;
	if (current_msr & UART_MSR_DDSR)
		port->icount.dsr++;
	if (current_msr & UART_MSR_TERI)
		port->icount.rng++;
	if (current_msr & UART_MSR_DDCD) {
		port->icount.dcd++;
		tty = tty_port_tty_get(&port->port);
		if (tty) {
			usb_serial_handle_dcd_change(port, tty,
					current_msr & UART_MSR_DCD);

			tty_kref_put(tty);
		}
	}

	wake_up_interruptible(&port->port.delta_msr_wait);
	mutex_unlock(&priv->lock);
}

static int f81232_set_mctrl(struct usb_serial_port *port,
					   unsigned int set, unsigned int clear)
{
	u8 val;
	int status;
	struct f81232_private *priv = usb_get_serial_port_data(port);

	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
		return 0;	/* no change */

	/* 'set' takes precedence over 'clear' */
	clear &= ~set;

	/* force enable interrupt with OUT2 */
	mutex_lock(&priv->lock);
	val = UART_MCR_OUT2 | priv->modem_control;

	if (clear & TIOCM_DTR)
		val &= ~UART_MCR_DTR;

	if (clear & TIOCM_RTS)
		val &= ~UART_MCR_RTS;

	if (set & TIOCM_DTR)
		val |= UART_MCR_DTR;

	if (set & TIOCM_RTS)
		val |= UART_MCR_RTS;

	dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
			val, priv->modem_control);

	status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
	if (status) {
		dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
		mutex_unlock(&priv->lock);
		return status;
	}

	priv->modem_control = val;
	mutex_unlock(&priv->lock);

	return 0;
}

static void f81232_update_line_status(struct usb_serial_port *port,
				      unsigned char *data,
				      size_t actual_length)
{
	struct f81232_private *priv = usb_get_serial_port_data(port);

	if (!actual_length)
		return;

	switch (data[0] & 0x07) {
	case 0x00: /* msr change */
		dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
		schedule_work(&priv->interrupt_work);
		break;
	case 0x02: /* tx-empty */
		break;
	case 0x04: /* rx data available */
		break;
	case 0x06: /* lsr change */
		/* we can forget it. the LSR will read from bulk-in */
		dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
		break;
	}
}

static void f81232_read_int_callback(struct urb *urb)
{
	struct usb_serial_port *port =  urb->context;
	unsigned char *data = urb->transfer_buffer;
	unsigned int actual_length = urb->actual_length;
	int status = urb->status;
	int retval;

	switch (status) {
	case 0:
		/* success */
		break;
	case -ECONNRESET:
	case -ENOENT:
	case -ESHUTDOWN:
		/* this urb is terminated, clean up */
		dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
			__func__, status);
		return;
	default:
		dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
			__func__, status);
		goto exit;
	}

	usb_serial_debug_data(&port->dev, __func__,
			      urb->actual_length, urb->transfer_buffer);

	f81232_update_line_status(port, data, actual_length);

exit:
	retval = usb_submit_urb(urb, GFP_ATOMIC);
	if (retval)
		dev_err(&urb->dev->dev,
			"%s - usb_submit_urb failed with result %d\n",
			__func__, retval);
}

static void f81232_process_read_urb(struct urb *urb)
{
	struct usb_serial_port *port = urb->context;
	unsigned char *data = urb->transfer_buffer;
	char tty_flag;
	unsigned int i;
	u8 lsr;

	/*
	 * When opening the port we get a 1-byte packet with the current LSR,
	 * which we discard.
	 */
	if ((urb->actual_length < 2) || (urb->actual_length % 2))
		return;

	/* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */

	for (i = 0; i < urb->actual_length; i += 2) {
		tty_flag = TTY_NORMAL;
		lsr = data[i];

		if (lsr & UART_LSR_BRK_ERROR_BITS) {
			if (lsr & UART_LSR_BI) {
				tty_flag = TTY_BREAK;
				port->icount.brk++;
				usb_serial_handle_break(port);
			} else if (lsr & UART_LSR_PE) {
				tty_flag = TTY_PARITY;
				port->icount.parity++;
			} else if (lsr & UART_LSR_FE) {
				tty_flag = TTY_FRAME;
				port->icount.frame++;
			}

			if (lsr & UART_LSR_OE) {
				port->icount.overrun++;
				tty_insert_flip_char(&port->port, 0,
						TTY_OVERRUN);
			}
		}

		if (port->port.console && port->sysrq) {
			if (usb_serial_handle_sysrq_char(port, data[i + 1]))
				continue;
		}

		tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
	}

	tty_flip_buffer_push(&port->port);
}

static void f81232_break_ctl(struct tty_struct *tty, int break_state)
{
	/* FIXME - Stubbed out for now */

	/*
	 * break_state = -1 to turn on break, and 0 to turn off break
	 * see drivers/char/tty_io.c to see it used.
	 * last_set_data_urb_value NEVER has the break bit set in it.
	 */
}

static void f81232_set_baudrate(struct usb_serial_port *port, speed_t baudrate)
{
	u8 lcr;
	int divisor;
	int status = 0;

	divisor = calc_baud_divisor(baudrate);

	status = f81232_get_register(port, LINE_CONTROL_REGISTER,
			 &lcr); /* get LCR */
	if (status) {
		dev_err(&port->dev, "%s failed to get LCR: %d\n",
			__func__, status);
		return;
	}

	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
			 lcr | UART_LCR_DLAB); /* Enable DLAB */
	if (status) {
		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
			__func__, status);
		return;
	}

	status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
			 divisor & 0x00ff); /* low */
	if (status) {
		dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
			__func__, status);
		goto reapply_lcr;
	}

	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
			 (divisor & 0xff00) >> 8); /* high */
	if (status) {
		dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
			__func__, status);
	}

reapply_lcr:
	status = f81232_set_register(port, LINE_CONTROL_REGISTER,
			lcr & ~UART_LCR_DLAB);
	if (status) {
		dev_err(&port->dev, "%s failed to set DLAB: %d\n",
			__func__, status);
	}
}

static int f81232_port_enable(struct usb_serial_port *port)
{
	u8 val;
	int status;

	/* fifo on, trigger8, clear TX/RX*/
	val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
			UART_FCR_CLEAR_XMIT;

	status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
	if (status) {
		dev_err(&port->dev, "%s failed to set FCR: %d\n",
			__func__, status);
		return status;
	}

	/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
			UART_IER_MSI);
	if (status) {
		dev_err(&port->dev, "%s failed to set IER: %d\n",
			__func__, status);
		return status;
	}

	return 0;
}

static int f81232_port_disable(struct usb_serial_port *port)
{
	int status;

	status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
	if (status) {
		dev_err(&port->dev, "%s failed to set IER: %d\n",
			__func__, status);
		return status;
	}

	return 0;
}

static void f81232_set_termios(struct tty_struct *tty,
		struct usb_serial_port *port, struct ktermios *old_termios)
{
	u8 new_lcr = 0;
	int status = 0;
	speed_t baudrate;

	/* Don't change anything if nothing has changed */
	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
		return;

	if (C_BAUD(tty) == B0)
		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);

	baudrate = tty_get_baud_rate(tty);
	if (baudrate > 0) {
		if (baudrate > F81232_MAX_BAUDRATE) {
			baudrate = F81232_MAX_BAUDRATE;
			tty_encode_baud_rate(tty, baudrate, baudrate);
		}
		f81232_set_baudrate(port, baudrate);
	}

	if (C_PARENB(tty)) {
		new_lcr |= UART_LCR_PARITY;

		if (!C_PARODD(tty))
			new_lcr |= UART_LCR_EPAR;

		if (C_CMSPAR(tty))
			new_lcr |= UART_LCR_SPAR;
	}

	if (C_CSTOPB(tty))
		new_lcr |= UART_LCR_STOP;

	switch (C_CSIZE(tty)) {
	case CS5:
		new_lcr |= UART_LCR_WLEN5;
		break;
	case CS6:
		new_lcr |= UART_LCR_WLEN6;
		break;
	case CS7:
		new_lcr |= UART_LCR_WLEN7;
		break;
	default:
	case CS8:
		new_lcr |= UART_LCR_WLEN8;
		break;
	}

	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
	if (status) {
		dev_err(&port->dev, "%s failed to set LCR: %d\n",
			__func__, status);
	}
}

static int f81232_tiocmget(struct tty_struct *tty)
{
	int r;
	struct usb_serial_port *port = tty->driver_data;
	struct f81232_private *port_priv = usb_get_serial_port_data(port);
	u8 mcr, msr;

	/* force get current MSR changed state */
	f81232_read_msr(port);

	mutex_lock(&port_priv->lock);
	mcr = port_priv->modem_control;
	msr = port_priv->modem_status;
	mutex_unlock(&port_priv->lock);

	r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
		(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
		(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
		(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
		(msr & UART_MSR_RI ? TIOCM_RI : 0) |
		(msr & UART_MSR_DSR ? TIOCM_DSR : 0);

	return r;
}

static int f81232_tiocmset(struct tty_struct *tty,
			unsigned int set, unsigned int clear)
{
	struct usb_serial_port *port = tty->driver_data;

	return f81232_set_mctrl(port, set, clear);
}

static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
{
	int result;

	result = f81232_port_enable(port);
	if (result)
		return result;

	/* Setup termios */
	if (tty)
		f81232_set_termios(tty, port, NULL);

	result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
	if (result) {
		dev_err(&port->dev, "%s - failed submitting interrupt urb,"
			" error %d\n", __func__, result);
		return result;
	}

	result = usb_serial_generic_open(tty, port);
	if (result) {
		usb_kill_urb(port->interrupt_in_urb);
		return result;
	}

	return 0;
}

static void f81232_close(struct usb_serial_port *port)
{
	f81232_port_disable(port);
	usb_serial_generic_close(port);
	usb_kill_urb(port->interrupt_in_urb);
}

static void f81232_dtr_rts(struct usb_serial_port *port, int on)
{
	if (on)
		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
	else
		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
}

static int f81232_carrier_raised(struct usb_serial_port *port)
{
	u8 msr;
	struct f81232_private *priv = usb_get_serial_port_data(port);

	mutex_lock(&priv->lock);
	msr = priv->modem_status;
	mutex_unlock(&priv->lock);

	if (msr & UART_MSR_DCD)
		return 1;
	return 0;
}

static int f81232_get_serial_info(struct usb_serial_port *port,
		unsigned long arg)
{
	struct serial_struct ser;

	memset(&ser, 0, sizeof(ser));

	ser.type = PORT_16550A;
	ser.line = port->minor;
	ser.port = port->port_number;
	ser.baud_base = F81232_MAX_BAUDRATE;

	if (copy_to_user((void __user *)arg, &ser, sizeof(ser)))
		return -EFAULT;

	return 0;
}

static int f81232_ioctl(struct tty_struct *tty,
			unsigned int cmd, unsigned long arg)
{
	struct usb_serial_port *port = tty->driver_data;

	switch (cmd) {
	case TIOCGSERIAL:
		return f81232_get_serial_info(port, arg);
	default:
		break;
	}
	return -ENOIOCTLCMD;
}

static void  f81232_interrupt_work(struct work_struct *work)
{
	struct f81232_private *priv =
		container_of(work, struct f81232_private, interrupt_work);

	f81232_read_msr(priv->port);
}

static int f81232_port_probe(struct usb_serial_port *port)
{
	struct f81232_private *priv;

	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	mutex_init(&priv->lock);
	INIT_WORK(&priv->interrupt_work,  f81232_interrupt_work);

	usb_set_serial_port_data(port, priv);

	port->port.drain_delay = 256;
	priv->port = port;

	return 0;
}

static int f81232_port_remove(struct usb_serial_port *port)
{
	struct f81232_private *priv;

	priv = usb_get_serial_port_data(port);
	kfree(priv);

	return 0;
}

static struct usb_serial_driver f81232_device = {
	.driver = {
		.owner =	THIS_MODULE,
		.name =		"f81232",
	},
	.id_table =		id_table,
	.num_ports =		1,
	.bulk_in_size =		256,
	.bulk_out_size =	256,
	.open =			f81232_open,
	.close =		f81232_close,
	.dtr_rts =		f81232_dtr_rts,
	.carrier_raised =	f81232_carrier_raised,
	.ioctl =		f81232_ioctl,
	.break_ctl =		f81232_break_ctl,
	.set_termios =		f81232_set_termios,
	.tiocmget =		f81232_tiocmget,
	.tiocmset =		f81232_tiocmset,
	.tiocmiwait =		usb_serial_generic_tiocmiwait,
	.process_read_urb =	f81232_process_read_urb,
	.read_int_callback =	f81232_read_int_callback,
	.port_probe =		f81232_port_probe,
	.port_remove =		f81232_port_remove,
};

static struct usb_serial_driver * const serial_drivers[] = {
	&f81232_device,
	NULL,
};

module_usb_serial_driver(serial_drivers, id_table);

MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
MODULE_LICENSE("GPL v2");