xref: /openbmc/linux/drivers/char/tlclk.c (revision 7211ec63)
1 /*
2  * Telecom Clock driver for Intel NetStructure(tm) MPCBL0010
3  *
4  * Copyright (C) 2005 Kontron Canada
5  *
6  * All rights reserved.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or (at
11  * your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
16  * NON INFRINGEMENT.  See the GNU General Public License for more
17  * details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  *
23  * Send feedback to <sebastien.bouchard@ca.kontron.com> and the current
24  * Maintainer  <mark.gross@intel.com>
25  *
26  * Description : This is the TELECOM CLOCK module driver for the ATCA
27  * MPCBL0010 ATCA computer.
28  */
29 
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/kernel.h>	/* printk() */
33 #include <linux/fs.h>		/* everything... */
34 #include <linux/errno.h>	/* error codes */
35 #include <linux/sched.h>
36 #include <linux/slab.h>
37 #include <linux/ioport.h>
38 #include <linux/interrupt.h>
39 #include <linux/spinlock.h>
40 #include <linux/mutex.h>
41 #include <linux/timer.h>
42 #include <linux/sysfs.h>
43 #include <linux/device.h>
44 #include <linux/miscdevice.h>
45 #include <linux/platform_device.h>
46 #include <asm/io.h>		/* inb/outb */
47 #include <linux/uaccess.h>
48 
49 MODULE_AUTHOR("Sebastien Bouchard <sebastien.bouchard@ca.kontron.com>");
50 MODULE_LICENSE("GPL");
51 
52 /*Hardware Reset of the PLL */
53 #define RESET_ON	0x00
54 #define RESET_OFF	0x01
55 
56 /* MODE SELECT */
57 #define NORMAL_MODE 	0x00
58 #define HOLDOVER_MODE	0x10
59 #define FREERUN_MODE	0x20
60 
61 /* FILTER SELECT */
62 #define FILTER_6HZ	0x04
63 #define FILTER_12HZ	0x00
64 
65 /* SELECT REFERENCE FREQUENCY */
66 #define REF_CLK1_8kHz		0x00
67 #define REF_CLK2_19_44MHz	0x02
68 
69 /* Select primary or secondary redundant clock */
70 #define PRIMARY_CLOCK	0x00
71 #define SECONDARY_CLOCK	0x01
72 
73 /* CLOCK TRANSMISSION DEFINE */
74 #define CLK_8kHz	0xff
75 #define CLK_16_384MHz	0xfb
76 
77 #define CLK_1_544MHz	0x00
78 #define CLK_2_048MHz	0x01
79 #define CLK_4_096MHz	0x02
80 #define CLK_6_312MHz	0x03
81 #define CLK_8_192MHz	0x04
82 #define CLK_19_440MHz	0x06
83 
84 #define CLK_8_592MHz	0x08
85 #define CLK_11_184MHz	0x09
86 #define CLK_34_368MHz	0x0b
87 #define CLK_44_736MHz	0x0a
88 
89 /* RECEIVED REFERENCE */
90 #define AMC_B1 0
91 #define AMC_B2 1
92 
93 /* HARDWARE SWITCHING DEFINE */
94 #define HW_ENABLE	0x80
95 #define HW_DISABLE	0x00
96 
97 /* HARDWARE SWITCHING MODE DEFINE */
98 #define PLL_HOLDOVER	0x40
99 #define LOST_CLOCK	0x00
100 
101 /* ALARMS DEFINE */
102 #define UNLOCK_MASK	0x10
103 #define HOLDOVER_MASK	0x20
104 #define SEC_LOST_MASK	0x40
105 #define PRI_LOST_MASK	0x80
106 
107 /* INTERRUPT CAUSE DEFINE */
108 
109 #define PRI_LOS_01_MASK		0x01
110 #define PRI_LOS_10_MASK		0x02
111 
112 #define SEC_LOS_01_MASK		0x04
113 #define SEC_LOS_10_MASK		0x08
114 
115 #define HOLDOVER_01_MASK	0x10
116 #define HOLDOVER_10_MASK	0x20
117 
118 #define UNLOCK_01_MASK		0x40
119 #define UNLOCK_10_MASK		0x80
120 
121 struct tlclk_alarms {
122 	__u32 lost_clocks;
123 	__u32 lost_primary_clock;
124 	__u32 lost_secondary_clock;
125 	__u32 primary_clock_back;
126 	__u32 secondary_clock_back;
127 	__u32 switchover_primary;
128 	__u32 switchover_secondary;
129 	__u32 pll_holdover;
130 	__u32 pll_end_holdover;
131 	__u32 pll_lost_sync;
132 	__u32 pll_sync;
133 };
134 /* Telecom clock I/O register definition */
135 #define TLCLK_BASE 0xa08
136 #define TLCLK_REG0 TLCLK_BASE
137 #define TLCLK_REG1 (TLCLK_BASE+1)
138 #define TLCLK_REG2 (TLCLK_BASE+2)
139 #define TLCLK_REG3 (TLCLK_BASE+3)
140 #define TLCLK_REG4 (TLCLK_BASE+4)
141 #define TLCLK_REG5 (TLCLK_BASE+5)
142 #define TLCLK_REG6 (TLCLK_BASE+6)
143 #define TLCLK_REG7 (TLCLK_BASE+7)
144 
145 #define SET_PORT_BITS(port, mask, val) outb(((inb(port) & mask) | val), port)
146 
147 /* 0 = Dynamic allocation of the major device number */
148 #define TLCLK_MAJOR 0
149 
150 /* sysfs interface definition:
151 Upon loading the driver will create a sysfs directory under
152 /sys/devices/platform/telco_clock.
153 
154 This directory exports the following interfaces.  There operation is
155 documented in the MCPBL0010 TPS under the Telecom Clock API section, 11.4.
156 alarms				:
157 current_ref			:
158 received_ref_clk3a		:
159 received_ref_clk3b		:
160 enable_clk3a_output		:
161 enable_clk3b_output		:
162 enable_clka0_output		:
163 enable_clka1_output		:
164 enable_clkb0_output		:
165 enable_clkb1_output		:
166 filter_select			:
167 hardware_switching		:
168 hardware_switching_mode		:
169 telclock_version		:
170 mode_select			:
171 refalign			:
172 reset				:
173 select_amcb1_transmit_clock	:
174 select_amcb2_transmit_clock	:
175 select_redundant_clock		:
176 select_ref_frequency		:
177 
178 All sysfs interfaces are integers in hex format, i.e echo 99 > refalign
179 has the same effect as echo 0x99 > refalign.
180 */
181 
182 static unsigned int telclk_interrupt;
183 
184 static int int_events;		/* Event that generate a interrupt */
185 static int got_event;		/* if events processing have been done */
186 
187 static void switchover_timeout(unsigned long data);
188 static struct timer_list switchover_timer =
189 	TIMER_INITIALIZER(switchover_timeout , 0, 0);
190 static unsigned long tlclk_timer_data;
191 
192 static struct tlclk_alarms *alarm_events;
193 
194 static DEFINE_SPINLOCK(event_lock);
195 
196 static int tlclk_major = TLCLK_MAJOR;
197 
198 static irqreturn_t tlclk_interrupt(int irq, void *dev_id);
199 
200 static DECLARE_WAIT_QUEUE_HEAD(wq);
201 
202 static unsigned long useflags;
203 static DEFINE_MUTEX(tlclk_mutex);
204 
205 static int tlclk_open(struct inode *inode, struct file *filp)
206 {
207 	int result;
208 
209 	mutex_lock(&tlclk_mutex);
210 	if (test_and_set_bit(0, &useflags)) {
211 		result = -EBUSY;
212 		/* this legacy device is always one per system and it doesn't
213 		 * know how to handle multiple concurrent clients.
214 		 */
215 		goto out;
216 	}
217 
218 	/* Make sure there is no interrupt pending while
219 	 * initialising interrupt handler */
220 	inb(TLCLK_REG6);
221 
222 	/* This device is wired through the FPGA IO space of the ATCA blade
223 	 * we can't share this IRQ */
224 	result = request_irq(telclk_interrupt, &tlclk_interrupt,
225 			     0, "telco_clock", tlclk_interrupt);
226 	if (result == -EBUSY)
227 		printk(KERN_ERR "tlclk: Interrupt can't be reserved.\n");
228 	else
229 		inb(TLCLK_REG6);	/* Clear interrupt events */
230 
231 out:
232 	mutex_unlock(&tlclk_mutex);
233 	return result;
234 }
235 
236 static int tlclk_release(struct inode *inode, struct file *filp)
237 {
238 	free_irq(telclk_interrupt, tlclk_interrupt);
239 	clear_bit(0, &useflags);
240 
241 	return 0;
242 }
243 
244 static ssize_t tlclk_read(struct file *filp, char __user *buf, size_t count,
245 		loff_t *f_pos)
246 {
247 	if (count < sizeof(struct tlclk_alarms))
248 		return -EIO;
249 	if (mutex_lock_interruptible(&tlclk_mutex))
250 		return -EINTR;
251 
252 
253 	wait_event_interruptible(wq, got_event);
254 	if (copy_to_user(buf, alarm_events, sizeof(struct tlclk_alarms))) {
255 		mutex_unlock(&tlclk_mutex);
256 		return -EFAULT;
257 	}
258 
259 	memset(alarm_events, 0, sizeof(struct tlclk_alarms));
260 	got_event = 0;
261 
262 	mutex_unlock(&tlclk_mutex);
263 	return  sizeof(struct tlclk_alarms);
264 }
265 
266 static const struct file_operations tlclk_fops = {
267 	.read = tlclk_read,
268 	.open = tlclk_open,
269 	.release = tlclk_release,
270 	.llseek = noop_llseek,
271 
272 };
273 
274 static struct miscdevice tlclk_miscdev = {
275 	.minor = MISC_DYNAMIC_MINOR,
276 	.name = "telco_clock",
277 	.fops = &tlclk_fops,
278 };
279 
280 static ssize_t show_current_ref(struct device *d,
281 		struct device_attribute *attr, char *buf)
282 {
283 	unsigned long ret_val;
284 	unsigned long flags;
285 
286 	spin_lock_irqsave(&event_lock, flags);
287 	ret_val = ((inb(TLCLK_REG1) & 0x08) >> 3);
288 	spin_unlock_irqrestore(&event_lock, flags);
289 
290 	return sprintf(buf, "0x%lX\n", ret_val);
291 }
292 
293 static DEVICE_ATTR(current_ref, S_IRUGO, show_current_ref, NULL);
294 
295 
296 static ssize_t show_telclock_version(struct device *d,
297 		struct device_attribute *attr, char *buf)
298 {
299 	unsigned long ret_val;
300 	unsigned long flags;
301 
302 	spin_lock_irqsave(&event_lock, flags);
303 	ret_val = inb(TLCLK_REG5);
304 	spin_unlock_irqrestore(&event_lock, flags);
305 
306 	return sprintf(buf, "0x%lX\n", ret_val);
307 }
308 
309 static DEVICE_ATTR(telclock_version, S_IRUGO,
310 		show_telclock_version, NULL);
311 
312 static ssize_t show_alarms(struct device *d,
313 		struct device_attribute *attr,  char *buf)
314 {
315 	unsigned long ret_val;
316 	unsigned long flags;
317 
318 	spin_lock_irqsave(&event_lock, flags);
319 	ret_val = (inb(TLCLK_REG2) & 0xf0);
320 	spin_unlock_irqrestore(&event_lock, flags);
321 
322 	return sprintf(buf, "0x%lX\n", ret_val);
323 }
324 
325 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
326 
327 static ssize_t store_received_ref_clk3a(struct device *d,
328 		 struct device_attribute *attr, const char *buf, size_t count)
329 {
330 	unsigned long tmp;
331 	unsigned char val;
332 	unsigned long flags;
333 
334 	sscanf(buf, "%lX", &tmp);
335 	dev_dbg(d, ": tmp = 0x%lX\n", tmp);
336 
337 	val = (unsigned char)tmp;
338 	spin_lock_irqsave(&event_lock, flags);
339 	SET_PORT_BITS(TLCLK_REG1, 0xef, val);
340 	spin_unlock_irqrestore(&event_lock, flags);
341 
342 	return strnlen(buf, count);
343 }
344 
345 static DEVICE_ATTR(received_ref_clk3a, (S_IWUSR|S_IWGRP), NULL,
346 		store_received_ref_clk3a);
347 
348 
349 static ssize_t store_received_ref_clk3b(struct device *d,
350 		 struct device_attribute *attr, const char *buf, size_t count)
351 {
352 	unsigned long tmp;
353 	unsigned char val;
354 	unsigned long flags;
355 
356 	sscanf(buf, "%lX", &tmp);
357 	dev_dbg(d, ": tmp = 0x%lX\n", tmp);
358 
359 	val = (unsigned char)tmp;
360 	spin_lock_irqsave(&event_lock, flags);
361 	SET_PORT_BITS(TLCLK_REG1, 0xdf, val << 1);
362 	spin_unlock_irqrestore(&event_lock, flags);
363 
364 	return strnlen(buf, count);
365 }
366 
367 static DEVICE_ATTR(received_ref_clk3b, (S_IWUSR|S_IWGRP), NULL,
368 		store_received_ref_clk3b);
369 
370 
371 static ssize_t store_enable_clk3b_output(struct device *d,
372 		 struct device_attribute *attr, const char *buf, size_t count)
373 {
374 	unsigned long tmp;
375 	unsigned char val;
376 	unsigned long flags;
377 
378 	sscanf(buf, "%lX", &tmp);
379 	dev_dbg(d, ": tmp = 0x%lX\n", tmp);
380 
381 	val = (unsigned char)tmp;
382 	spin_lock_irqsave(&event_lock, flags);
383 	SET_PORT_BITS(TLCLK_REG3, 0x7f, val << 7);
384 	spin_unlock_irqrestore(&event_lock, flags);
385 
386 	return strnlen(buf, count);
387 }
388 
389 static DEVICE_ATTR(enable_clk3b_output, (S_IWUSR|S_IWGRP), NULL,
390 		store_enable_clk3b_output);
391 
392 static ssize_t store_enable_clk3a_output(struct device *d,
393 		 struct device_attribute *attr, const char *buf, size_t count)
394 {
395 	unsigned long flags;
396 	unsigned long tmp;
397 	unsigned char val;
398 
399 	sscanf(buf, "%lX", &tmp);
400 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
401 
402 	val = (unsigned char)tmp;
403 	spin_lock_irqsave(&event_lock, flags);
404 	SET_PORT_BITS(TLCLK_REG3, 0xbf, val << 6);
405 	spin_unlock_irqrestore(&event_lock, flags);
406 
407 	return strnlen(buf, count);
408 }
409 
410 static DEVICE_ATTR(enable_clk3a_output, (S_IWUSR|S_IWGRP), NULL,
411 		store_enable_clk3a_output);
412 
413 static ssize_t store_enable_clkb1_output(struct device *d,
414 		 struct device_attribute *attr, const char *buf, size_t count)
415 {
416 	unsigned long flags;
417 	unsigned long tmp;
418 	unsigned char val;
419 
420 	sscanf(buf, "%lX", &tmp);
421 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
422 
423 	val = (unsigned char)tmp;
424 	spin_lock_irqsave(&event_lock, flags);
425 	SET_PORT_BITS(TLCLK_REG2, 0xf7, val << 3);
426 	spin_unlock_irqrestore(&event_lock, flags);
427 
428 	return strnlen(buf, count);
429 }
430 
431 static DEVICE_ATTR(enable_clkb1_output, (S_IWUSR|S_IWGRP), NULL,
432 		store_enable_clkb1_output);
433 
434 
435 static ssize_t store_enable_clka1_output(struct device *d,
436 		 struct device_attribute *attr, const char *buf, size_t count)
437 {
438 	unsigned long flags;
439 	unsigned long tmp;
440 	unsigned char val;
441 
442 	sscanf(buf, "%lX", &tmp);
443 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
444 
445 	val = (unsigned char)tmp;
446 	spin_lock_irqsave(&event_lock, flags);
447 	SET_PORT_BITS(TLCLK_REG2, 0xfb, val << 2);
448 	spin_unlock_irqrestore(&event_lock, flags);
449 
450 	return strnlen(buf, count);
451 }
452 
453 static DEVICE_ATTR(enable_clka1_output, (S_IWUSR|S_IWGRP), NULL,
454 		store_enable_clka1_output);
455 
456 static ssize_t store_enable_clkb0_output(struct device *d,
457 		 struct device_attribute *attr, const char *buf, size_t count)
458 {
459 	unsigned long flags;
460 	unsigned long tmp;
461 	unsigned char val;
462 
463 	sscanf(buf, "%lX", &tmp);
464 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
465 
466 	val = (unsigned char)tmp;
467 	spin_lock_irqsave(&event_lock, flags);
468 	SET_PORT_BITS(TLCLK_REG2, 0xfd, val << 1);
469 	spin_unlock_irqrestore(&event_lock, flags);
470 
471 	return strnlen(buf, count);
472 }
473 
474 static DEVICE_ATTR(enable_clkb0_output, (S_IWUSR|S_IWGRP), NULL,
475 		store_enable_clkb0_output);
476 
477 static ssize_t store_enable_clka0_output(struct device *d,
478 		 struct device_attribute *attr, const char *buf, size_t count)
479 {
480 	unsigned long flags;
481 	unsigned long tmp;
482 	unsigned char val;
483 
484 	sscanf(buf, "%lX", &tmp);
485 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
486 
487 	val = (unsigned char)tmp;
488 	spin_lock_irqsave(&event_lock, flags);
489 	SET_PORT_BITS(TLCLK_REG2, 0xfe, val);
490 	spin_unlock_irqrestore(&event_lock, flags);
491 
492 	return strnlen(buf, count);
493 }
494 
495 static DEVICE_ATTR(enable_clka0_output, (S_IWUSR|S_IWGRP), NULL,
496 		store_enable_clka0_output);
497 
498 static ssize_t store_select_amcb2_transmit_clock(struct device *d,
499 		struct device_attribute *attr, const char *buf, size_t count)
500 {
501 	unsigned long flags;
502 	unsigned long tmp;
503 	unsigned char val;
504 
505 	sscanf(buf, "%lX", &tmp);
506 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
507 
508 	val = (unsigned char)tmp;
509 	spin_lock_irqsave(&event_lock, flags);
510 		if ((val == CLK_8kHz) || (val == CLK_16_384MHz)) {
511 			SET_PORT_BITS(TLCLK_REG3, 0xc7, 0x28);
512 			SET_PORT_BITS(TLCLK_REG1, 0xfb, ~val);
513 		} else if (val >= CLK_8_592MHz) {
514 			SET_PORT_BITS(TLCLK_REG3, 0xc7, 0x38);
515 			switch (val) {
516 			case CLK_8_592MHz:
517 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
518 				break;
519 			case CLK_11_184MHz:
520 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 0);
521 				break;
522 			case CLK_34_368MHz:
523 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 3);
524 				break;
525 			case CLK_44_736MHz:
526 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
527 				break;
528 			}
529 		} else
530 			SET_PORT_BITS(TLCLK_REG3, 0xc7, val << 3);
531 
532 	spin_unlock_irqrestore(&event_lock, flags);
533 
534 	return strnlen(buf, count);
535 }
536 
537 static DEVICE_ATTR(select_amcb2_transmit_clock, (S_IWUSR|S_IWGRP), NULL,
538 	store_select_amcb2_transmit_clock);
539 
540 static ssize_t store_select_amcb1_transmit_clock(struct device *d,
541 		 struct device_attribute *attr, const char *buf, size_t count)
542 {
543 	unsigned long tmp;
544 	unsigned char val;
545 	unsigned long flags;
546 
547 	sscanf(buf, "%lX", &tmp);
548 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
549 
550 	val = (unsigned char)tmp;
551 	spin_lock_irqsave(&event_lock, flags);
552 		if ((val == CLK_8kHz) || (val == CLK_16_384MHz)) {
553 			SET_PORT_BITS(TLCLK_REG3, 0xf8, 0x5);
554 			SET_PORT_BITS(TLCLK_REG1, 0xfb, ~val);
555 		} else if (val >= CLK_8_592MHz) {
556 			SET_PORT_BITS(TLCLK_REG3, 0xf8, 0x7);
557 			switch (val) {
558 			case CLK_8_592MHz:
559 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 2);
560 				break;
561 			case CLK_11_184MHz:
562 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 0);
563 				break;
564 			case CLK_34_368MHz:
565 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 3);
566 				break;
567 			case CLK_44_736MHz:
568 				SET_PORT_BITS(TLCLK_REG0, 0xfc, 1);
569 				break;
570 			}
571 		} else
572 			SET_PORT_BITS(TLCLK_REG3, 0xf8, val);
573 	spin_unlock_irqrestore(&event_lock, flags);
574 
575 	return strnlen(buf, count);
576 }
577 
578 static DEVICE_ATTR(select_amcb1_transmit_clock, (S_IWUSR|S_IWGRP), NULL,
579 		store_select_amcb1_transmit_clock);
580 
581 static ssize_t store_select_redundant_clock(struct device *d,
582 		 struct device_attribute *attr, const char *buf, size_t count)
583 {
584 	unsigned long tmp;
585 	unsigned char val;
586 	unsigned long flags;
587 
588 	sscanf(buf, "%lX", &tmp);
589 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
590 
591 	val = (unsigned char)tmp;
592 	spin_lock_irqsave(&event_lock, flags);
593 	SET_PORT_BITS(TLCLK_REG1, 0xfe, val);
594 	spin_unlock_irqrestore(&event_lock, flags);
595 
596 	return strnlen(buf, count);
597 }
598 
599 static DEVICE_ATTR(select_redundant_clock, (S_IWUSR|S_IWGRP), NULL,
600 		store_select_redundant_clock);
601 
602 static ssize_t store_select_ref_frequency(struct device *d,
603 		 struct device_attribute *attr, const char *buf, size_t count)
604 {
605 	unsigned long tmp;
606 	unsigned char val;
607 	unsigned long flags;
608 
609 	sscanf(buf, "%lX", &tmp);
610 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
611 
612 	val = (unsigned char)tmp;
613 	spin_lock_irqsave(&event_lock, flags);
614 	SET_PORT_BITS(TLCLK_REG1, 0xfd, val);
615 	spin_unlock_irqrestore(&event_lock, flags);
616 
617 	return strnlen(buf, count);
618 }
619 
620 static DEVICE_ATTR(select_ref_frequency, (S_IWUSR|S_IWGRP), NULL,
621 		store_select_ref_frequency);
622 
623 static ssize_t store_filter_select(struct device *d,
624 		 struct device_attribute *attr, const char *buf, size_t count)
625 {
626 	unsigned long tmp;
627 	unsigned char val;
628 	unsigned long flags;
629 
630 	sscanf(buf, "%lX", &tmp);
631 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
632 
633 	val = (unsigned char)tmp;
634 	spin_lock_irqsave(&event_lock, flags);
635 	SET_PORT_BITS(TLCLK_REG0, 0xfb, val);
636 	spin_unlock_irqrestore(&event_lock, flags);
637 
638 	return strnlen(buf, count);
639 }
640 
641 static DEVICE_ATTR(filter_select, (S_IWUSR|S_IWGRP), NULL, store_filter_select);
642 
643 static ssize_t store_hardware_switching_mode(struct device *d,
644 		 struct device_attribute *attr, const char *buf, size_t count)
645 {
646 	unsigned long tmp;
647 	unsigned char val;
648 	unsigned long flags;
649 
650 	sscanf(buf, "%lX", &tmp);
651 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
652 
653 	val = (unsigned char)tmp;
654 	spin_lock_irqsave(&event_lock, flags);
655 	SET_PORT_BITS(TLCLK_REG0, 0xbf, val);
656 	spin_unlock_irqrestore(&event_lock, flags);
657 
658 	return strnlen(buf, count);
659 }
660 
661 static DEVICE_ATTR(hardware_switching_mode, (S_IWUSR|S_IWGRP), NULL,
662 		store_hardware_switching_mode);
663 
664 static ssize_t store_hardware_switching(struct device *d,
665 		 struct device_attribute *attr, const char *buf, size_t count)
666 {
667 	unsigned long tmp;
668 	unsigned char val;
669 	unsigned long flags;
670 
671 	sscanf(buf, "%lX", &tmp);
672 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
673 
674 	val = (unsigned char)tmp;
675 	spin_lock_irqsave(&event_lock, flags);
676 	SET_PORT_BITS(TLCLK_REG0, 0x7f, val);
677 	spin_unlock_irqrestore(&event_lock, flags);
678 
679 	return strnlen(buf, count);
680 }
681 
682 static DEVICE_ATTR(hardware_switching, (S_IWUSR|S_IWGRP), NULL,
683 		store_hardware_switching);
684 
685 static ssize_t store_refalign (struct device *d,
686 		 struct device_attribute *attr, const char *buf, size_t count)
687 {
688 	unsigned long tmp;
689 	unsigned long flags;
690 
691 	sscanf(buf, "%lX", &tmp);
692 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
693 	spin_lock_irqsave(&event_lock, flags);
694 	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0);
695 	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0x08);
696 	SET_PORT_BITS(TLCLK_REG0, 0xf7, 0);
697 	spin_unlock_irqrestore(&event_lock, flags);
698 
699 	return strnlen(buf, count);
700 }
701 
702 static DEVICE_ATTR(refalign, (S_IWUSR|S_IWGRP), NULL, store_refalign);
703 
704 static ssize_t store_mode_select (struct device *d,
705 		 struct device_attribute *attr, const char *buf, size_t count)
706 {
707 	unsigned long tmp;
708 	unsigned char val;
709 	unsigned long flags;
710 
711 	sscanf(buf, "%lX", &tmp);
712 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
713 
714 	val = (unsigned char)tmp;
715 	spin_lock_irqsave(&event_lock, flags);
716 	SET_PORT_BITS(TLCLK_REG0, 0xcf, val);
717 	spin_unlock_irqrestore(&event_lock, flags);
718 
719 	return strnlen(buf, count);
720 }
721 
722 static DEVICE_ATTR(mode_select, (S_IWUSR|S_IWGRP), NULL, store_mode_select);
723 
724 static ssize_t store_reset (struct device *d,
725 		 struct device_attribute *attr, const char *buf, size_t count)
726 {
727 	unsigned long tmp;
728 	unsigned char val;
729 	unsigned long flags;
730 
731 	sscanf(buf, "%lX", &tmp);
732 	dev_dbg(d, "tmp = 0x%lX\n", tmp);
733 
734 	val = (unsigned char)tmp;
735 	spin_lock_irqsave(&event_lock, flags);
736 	SET_PORT_BITS(TLCLK_REG4, 0xfd, val);
737 	spin_unlock_irqrestore(&event_lock, flags);
738 
739 	return strnlen(buf, count);
740 }
741 
742 static DEVICE_ATTR(reset, (S_IWUSR|S_IWGRP), NULL, store_reset);
743 
744 static struct attribute *tlclk_sysfs_entries[] = {
745 	&dev_attr_current_ref.attr,
746 	&dev_attr_telclock_version.attr,
747 	&dev_attr_alarms.attr,
748 	&dev_attr_received_ref_clk3a.attr,
749 	&dev_attr_received_ref_clk3b.attr,
750 	&dev_attr_enable_clk3a_output.attr,
751 	&dev_attr_enable_clk3b_output.attr,
752 	&dev_attr_enable_clkb1_output.attr,
753 	&dev_attr_enable_clka1_output.attr,
754 	&dev_attr_enable_clkb0_output.attr,
755 	&dev_attr_enable_clka0_output.attr,
756 	&dev_attr_select_amcb1_transmit_clock.attr,
757 	&dev_attr_select_amcb2_transmit_clock.attr,
758 	&dev_attr_select_redundant_clock.attr,
759 	&dev_attr_select_ref_frequency.attr,
760 	&dev_attr_filter_select.attr,
761 	&dev_attr_hardware_switching_mode.attr,
762 	&dev_attr_hardware_switching.attr,
763 	&dev_attr_refalign.attr,
764 	&dev_attr_mode_select.attr,
765 	&dev_attr_reset.attr,
766 	NULL
767 };
768 
769 static const struct attribute_group tlclk_attribute_group = {
770 	.name = NULL,		/* put in device directory */
771 	.attrs = tlclk_sysfs_entries,
772 };
773 
774 static struct platform_device *tlclk_device;
775 
776 static int __init tlclk_init(void)
777 {
778 	int ret;
779 
780 	ret = register_chrdev(tlclk_major, "telco_clock", &tlclk_fops);
781 	if (ret < 0) {
782 		printk(KERN_ERR "tlclk: can't get major %d.\n", tlclk_major);
783 		return ret;
784 	}
785 	tlclk_major = ret;
786 	alarm_events = kzalloc( sizeof(struct tlclk_alarms), GFP_KERNEL);
787 	if (!alarm_events) {
788 		ret = -ENOMEM;
789 		goto out1;
790 	}
791 
792 	/* Read telecom clock IRQ number (Set by BIOS) */
793 	if (!request_region(TLCLK_BASE, 8, "telco_clock")) {
794 		printk(KERN_ERR "tlclk: request_region 0x%X failed.\n",
795 			TLCLK_BASE);
796 		ret = -EBUSY;
797 		goto out2;
798 	}
799 	telclk_interrupt = (inb(TLCLK_REG7) & 0x0f);
800 
801 	if (0x0F == telclk_interrupt ) { /* not MCPBL0010 ? */
802 		printk(KERN_ERR "telclk_interrupt = 0x%x non-mcpbl0010 hw.\n",
803 			telclk_interrupt);
804 		ret = -ENXIO;
805 		goto out3;
806 	}
807 
808 	init_timer(&switchover_timer);
809 
810 	ret = misc_register(&tlclk_miscdev);
811 	if (ret < 0) {
812 		printk(KERN_ERR "tlclk: misc_register returns %d.\n", ret);
813 		goto out3;
814 	}
815 
816 	tlclk_device = platform_device_register_simple("telco_clock",
817 				-1, NULL, 0);
818 	if (IS_ERR(tlclk_device)) {
819 		printk(KERN_ERR "tlclk: platform_device_register failed.\n");
820 		ret = PTR_ERR(tlclk_device);
821 		goto out4;
822 	}
823 
824 	ret = sysfs_create_group(&tlclk_device->dev.kobj,
825 			&tlclk_attribute_group);
826 	if (ret) {
827 		printk(KERN_ERR "tlclk: failed to create sysfs device attributes.\n");
828 		goto out5;
829 	}
830 
831 	return 0;
832 out5:
833 	platform_device_unregister(tlclk_device);
834 out4:
835 	misc_deregister(&tlclk_miscdev);
836 out3:
837 	release_region(TLCLK_BASE, 8);
838 out2:
839 	kfree(alarm_events);
840 out1:
841 	unregister_chrdev(tlclk_major, "telco_clock");
842 	return ret;
843 }
844 
845 static void __exit tlclk_cleanup(void)
846 {
847 	sysfs_remove_group(&tlclk_device->dev.kobj, &tlclk_attribute_group);
848 	platform_device_unregister(tlclk_device);
849 	misc_deregister(&tlclk_miscdev);
850 	unregister_chrdev(tlclk_major, "telco_clock");
851 
852 	release_region(TLCLK_BASE, 8);
853 	del_timer_sync(&switchover_timer);
854 	kfree(alarm_events);
855 
856 }
857 
858 static void switchover_timeout(unsigned long data)
859 {
860 	unsigned long flags = *(unsigned long *) data;
861 
862 	if ((flags & 1)) {
863 		if ((inb(TLCLK_REG1) & 0x08) != (flags & 0x08))
864 			alarm_events->switchover_primary++;
865 	} else {
866 		if ((inb(TLCLK_REG1) & 0x08) != (flags & 0x08))
867 			alarm_events->switchover_secondary++;
868 	}
869 
870 	/* Alarm processing is done, wake up read task */
871 	del_timer(&switchover_timer);
872 	got_event = 1;
873 	wake_up(&wq);
874 }
875 
876 static irqreturn_t tlclk_interrupt(int irq, void *dev_id)
877 {
878 	unsigned long flags;
879 
880 	spin_lock_irqsave(&event_lock, flags);
881 	/* Read and clear interrupt events */
882 	int_events = inb(TLCLK_REG6);
883 
884 	/* Primary_Los changed from 0 to 1 ? */
885 	if (int_events & PRI_LOS_01_MASK) {
886 		if (inb(TLCLK_REG2) & SEC_LOST_MASK)
887 			alarm_events->lost_clocks++;
888 		else
889 			alarm_events->lost_primary_clock++;
890 	}
891 
892 	/* Primary_Los changed from 1 to 0 ? */
893 	if (int_events & PRI_LOS_10_MASK) {
894 		alarm_events->primary_clock_back++;
895 		SET_PORT_BITS(TLCLK_REG1, 0xFE, 1);
896 	}
897 	/* Secondary_Los changed from 0 to 1 ? */
898 	if (int_events & SEC_LOS_01_MASK) {
899 		if (inb(TLCLK_REG2) & PRI_LOST_MASK)
900 			alarm_events->lost_clocks++;
901 		else
902 			alarm_events->lost_secondary_clock++;
903 	}
904 	/* Secondary_Los changed from 1 to 0 ? */
905 	if (int_events & SEC_LOS_10_MASK) {
906 		alarm_events->secondary_clock_back++;
907 		SET_PORT_BITS(TLCLK_REG1, 0xFE, 0);
908 	}
909 	if (int_events & HOLDOVER_10_MASK)
910 		alarm_events->pll_end_holdover++;
911 
912 	if (int_events & UNLOCK_01_MASK)
913 		alarm_events->pll_lost_sync++;
914 
915 	if (int_events & UNLOCK_10_MASK)
916 		alarm_events->pll_sync++;
917 
918 	/* Holdover changed from 0 to 1 ? */
919 	if (int_events & HOLDOVER_01_MASK) {
920 		alarm_events->pll_holdover++;
921 
922 		/* TIMEOUT in ~10ms */
923 		switchover_timer.expires = jiffies + msecs_to_jiffies(10);
924 		tlclk_timer_data = inb(TLCLK_REG1);
925 		switchover_timer.data = (unsigned long) &tlclk_timer_data;
926 		mod_timer(&switchover_timer, switchover_timer.expires);
927 	} else {
928 		got_event = 1;
929 		wake_up(&wq);
930 	}
931 	spin_unlock_irqrestore(&event_lock, flags);
932 
933 	return IRQ_HANDLED;
934 }
935 
936 module_init(tlclk_init);
937 module_exit(tlclk_cleanup);
938