xref: /linux/arch/s390/kernel/time.c (revision ed3174d93c342b8b2eeba6bbd124707d55304a7b)
1 /*
2  *  arch/s390/kernel/time.c
3  *    Time of day based timer functions.
4  *
5  *  S390 version
6  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
7  *    Author(s): Hartmut Penner (hp@de.ibm.com),
8  *               Martin Schwidefsky (schwidefsky@de.ibm.com),
9  *               Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
10  *
11  *  Derived from "arch/i386/kernel/time.c"
12  *    Copyright (C) 1991, 1992, 1995  Linus Torvalds
13  */
14 
15 #include <linux/errno.h>
16 #include <linux/module.h>
17 #include <linux/sched.h>
18 #include <linux/kernel.h>
19 #include <linux/param.h>
20 #include <linux/string.h>
21 #include <linux/mm.h>
22 #include <linux/interrupt.h>
23 #include <linux/time.h>
24 #include <linux/sysdev.h>
25 #include <linux/delay.h>
26 #include <linux/init.h>
27 #include <linux/smp.h>
28 #include <linux/types.h>
29 #include <linux/profile.h>
30 #include <linux/timex.h>
31 #include <linux/notifier.h>
32 #include <linux/clocksource.h>
33 
34 #include <asm/uaccess.h>
35 #include <asm/delay.h>
36 #include <asm/s390_ext.h>
37 #include <asm/div64.h>
38 #include <asm/irq.h>
39 #include <asm/irq_regs.h>
40 #include <asm/timer.h>
41 #include <asm/etr.h>
42 
43 /* change this if you have some constant time drift */
44 #define USECS_PER_JIFFY     ((unsigned long) 1000000/HZ)
45 #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12)
46 
47 /* The value of the TOD clock for 1.1.1970. */
48 #define TOD_UNIX_EPOCH 0x7d91048bca000000ULL
49 
50 /*
51  * Create a small time difference between the timer interrupts
52  * on the different cpus to avoid lock contention.
53  */
54 #define CPU_DEVIATION       (smp_processor_id() << 12)
55 
56 #define TICK_SIZE tick
57 
58 static ext_int_info_t ext_int_info_cc;
59 static ext_int_info_t ext_int_etr_cc;
60 static u64 init_timer_cc;
61 static u64 jiffies_timer_cc;
62 static u64 xtime_cc;
63 
64 /*
65  * Scheduler clock - returns current time in nanosec units.
66  */
67 unsigned long long sched_clock(void)
68 {
69 	return ((get_clock() - jiffies_timer_cc) * 125) >> 9;
70 }
71 
72 /*
73  * Monotonic_clock - returns # of nanoseconds passed since time_init()
74  */
75 unsigned long long monotonic_clock(void)
76 {
77 	return sched_clock();
78 }
79 EXPORT_SYMBOL(monotonic_clock);
80 
81 void tod_to_timeval(__u64 todval, struct timespec *xtime)
82 {
83 	unsigned long long sec;
84 
85 	sec = todval >> 12;
86 	do_div(sec, 1000000);
87 	xtime->tv_sec = sec;
88 	todval -= (sec * 1000000) << 12;
89 	xtime->tv_nsec = ((todval * 1000) >> 12);
90 }
91 
92 #ifdef CONFIG_PROFILING
93 #define s390_do_profile()	profile_tick(CPU_PROFILING)
94 #else
95 #define s390_do_profile()	do { ; } while(0)
96 #endif /* CONFIG_PROFILING */
97 
98 /*
99  * Advance the per cpu tick counter up to the time given with the
100  * "time" argument. The per cpu update consists of accounting
101  * the virtual cpu time, calling update_process_times and calling
102  * the profiling hook. If xtime is before time it is advanced as well.
103  */
104 void account_ticks(u64 time)
105 {
106 	__u32 ticks;
107 	__u64 tmp;
108 
109 	/* Calculate how many ticks have passed. */
110 	if (time < S390_lowcore.jiffy_timer)
111 		return;
112 	tmp = time - S390_lowcore.jiffy_timer;
113 	if (tmp >= 2*CLK_TICKS_PER_JIFFY) {  /* more than two ticks ? */
114 		ticks = __div(tmp, CLK_TICKS_PER_JIFFY) + 1;
115 		S390_lowcore.jiffy_timer +=
116 			CLK_TICKS_PER_JIFFY * (__u64) ticks;
117 	} else if (tmp >= CLK_TICKS_PER_JIFFY) {
118 		ticks = 2;
119 		S390_lowcore.jiffy_timer += 2*CLK_TICKS_PER_JIFFY;
120 	} else {
121 		ticks = 1;
122 		S390_lowcore.jiffy_timer += CLK_TICKS_PER_JIFFY;
123 	}
124 
125 #ifdef CONFIG_SMP
126 	/*
127 	 * Do not rely on the boot cpu to do the calls to do_timer.
128 	 * Spread it over all cpus instead.
129 	 */
130 	write_seqlock(&xtime_lock);
131 	if (S390_lowcore.jiffy_timer > xtime_cc) {
132 		__u32 xticks;
133 		tmp = S390_lowcore.jiffy_timer - xtime_cc;
134 		if (tmp >= 2*CLK_TICKS_PER_JIFFY) {
135 			xticks = __div(tmp, CLK_TICKS_PER_JIFFY);
136 			xtime_cc += (__u64) xticks * CLK_TICKS_PER_JIFFY;
137 		} else {
138 			xticks = 1;
139 			xtime_cc += CLK_TICKS_PER_JIFFY;
140 		}
141 		do_timer(xticks);
142 	}
143 	write_sequnlock(&xtime_lock);
144 #else
145 	do_timer(ticks);
146 #endif
147 
148 	while (ticks--)
149 		update_process_times(user_mode(get_irq_regs()));
150 
151 	s390_do_profile();
152 }
153 
154 #ifdef CONFIG_NO_IDLE_HZ
155 
156 #ifdef CONFIG_NO_IDLE_HZ_INIT
157 int sysctl_hz_timer = 0;
158 #else
159 int sysctl_hz_timer = 1;
160 #endif
161 
162 /*
163  * Stop the HZ tick on the current CPU.
164  * Only cpu_idle may call this function.
165  */
166 static void stop_hz_timer(void)
167 {
168 	unsigned long flags;
169 	unsigned long seq, next;
170 	__u64 timer, todval;
171 	int cpu = smp_processor_id();
172 
173 	if (sysctl_hz_timer != 0)
174 		return;
175 
176 	cpu_set(cpu, nohz_cpu_mask);
177 
178 	/*
179 	 * Leave the clock comparator set up for the next timer
180 	 * tick if either rcu or a softirq is pending.
181 	 */
182 	if (rcu_needs_cpu(cpu) || local_softirq_pending()) {
183 		cpu_clear(cpu, nohz_cpu_mask);
184 		return;
185 	}
186 
187 	/*
188 	 * This cpu is going really idle. Set up the clock comparator
189 	 * for the next event.
190 	 */
191 	next = next_timer_interrupt();
192 	do {
193 		seq = read_seqbegin_irqsave(&xtime_lock, flags);
194 		timer = ((__u64) next) - ((__u64) jiffies) + jiffies_64;
195 	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
196 	todval = -1ULL;
197 	/* Be careful about overflows. */
198 	if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
199 		timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
200 		if (timer >= jiffies_timer_cc)
201 			todval = timer;
202 	}
203 	set_clock_comparator(todval);
204 }
205 
206 /*
207  * Start the HZ tick on the current CPU.
208  * Only cpu_idle may call this function.
209  */
210 static void start_hz_timer(void)
211 {
212 	BUG_ON(!in_interrupt());
213 
214 	if (!cpu_isset(smp_processor_id(), nohz_cpu_mask))
215 		return;
216 	account_ticks(get_clock());
217 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
218 	cpu_clear(smp_processor_id(), nohz_cpu_mask);
219 }
220 
221 static int nohz_idle_notify(struct notifier_block *self,
222 			    unsigned long action, void *hcpu)
223 {
224 	switch (action) {
225 	case S390_CPU_IDLE:
226 		stop_hz_timer();
227 		break;
228 	case S390_CPU_NOT_IDLE:
229 		start_hz_timer();
230 		break;
231 	}
232 	return NOTIFY_OK;
233 }
234 
235 static struct notifier_block nohz_idle_nb = {
236 	.notifier_call = nohz_idle_notify,
237 };
238 
239 static void __init nohz_init(void)
240 {
241 	if (register_idle_notifier(&nohz_idle_nb))
242 		panic("Couldn't register idle notifier");
243 }
244 
245 #endif
246 
247 /*
248  * Set up per cpu jiffy timer and set the clock comparator.
249  */
250 static void setup_jiffy_timer(void)
251 {
252 	/* Set up clock comparator to next jiffy. */
253 	S390_lowcore.jiffy_timer =
254 		jiffies_timer_cc + (jiffies_64 + 1) * CLK_TICKS_PER_JIFFY;
255 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
256 }
257 
258 /*
259  * Set up lowcore and control register of the current cpu to
260  * enable TOD clock and clock comparator interrupts.
261  */
262 void init_cpu_timer(void)
263 {
264 	setup_jiffy_timer();
265 
266 	/* Enable clock comparator timer interrupt. */
267 	__ctl_set_bit(0,11);
268 
269 	/* Always allow ETR external interrupts, even without an ETR. */
270 	__ctl_set_bit(0, 4);
271 }
272 
273 static void clock_comparator_interrupt(__u16 code)
274 {
275 	/* set clock comparator for next tick */
276 	set_clock_comparator(S390_lowcore.jiffy_timer + CPU_DEVIATION);
277 }
278 
279 static void etr_reset(void);
280 static void etr_ext_handler(__u16);
281 
282 /*
283  * Get the TOD clock running.
284  */
285 static u64 __init reset_tod_clock(void)
286 {
287 	u64 time;
288 
289 	etr_reset();
290 	if (store_clock(&time) == 0)
291 		return time;
292 	/* TOD clock not running. Set the clock to Unix Epoch. */
293 	if (set_clock(TOD_UNIX_EPOCH) != 0 || store_clock(&time) != 0)
294 		panic("TOD clock not operational.");
295 
296 	return TOD_UNIX_EPOCH;
297 }
298 
299 static cycle_t read_tod_clock(void)
300 {
301 	return get_clock();
302 }
303 
304 static struct clocksource clocksource_tod = {
305 	.name		= "tod",
306 	.rating		= 400,
307 	.read		= read_tod_clock,
308 	.mask		= -1ULL,
309 	.mult		= 1000,
310 	.shift		= 12,
311 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
312 };
313 
314 
315 /*
316  * Initialize the TOD clock and the CPU timer of
317  * the boot cpu.
318  */
319 void __init time_init(void)
320 {
321 	init_timer_cc = reset_tod_clock();
322 	xtime_cc = init_timer_cc + CLK_TICKS_PER_JIFFY;
323 	jiffies_timer_cc = init_timer_cc - jiffies_64 * CLK_TICKS_PER_JIFFY;
324 
325 	/* set xtime */
326 	tod_to_timeval(init_timer_cc - TOD_UNIX_EPOCH, &xtime);
327         set_normalized_timespec(&wall_to_monotonic,
328                                 -xtime.tv_sec, -xtime.tv_nsec);
329 
330 	/* request the clock comparator external interrupt */
331 	if (register_early_external_interrupt(0x1004,
332 					      clock_comparator_interrupt,
333 					      &ext_int_info_cc) != 0)
334                 panic("Couldn't request external interrupt 0x1004");
335 
336 	if (clocksource_register(&clocksource_tod) != 0)
337 		panic("Could not register TOD clock source");
338 
339 	/* request the etr external interrupt */
340 	if (register_early_external_interrupt(0x1406, etr_ext_handler,
341 					      &ext_int_etr_cc) != 0)
342 		panic("Couldn't request external interrupt 0x1406");
343 
344 	/* Enable TOD clock interrupts on the boot cpu. */
345 	init_cpu_timer();
346 
347 #ifdef CONFIG_NO_IDLE_HZ
348 	nohz_init();
349 #endif
350 
351 #ifdef CONFIG_VIRT_TIMER
352 	vtime_init();
353 #endif
354 }
355 
356 /*
357  * External Time Reference (ETR) code.
358  */
359 static int etr_port0_online;
360 static int etr_port1_online;
361 
362 static int __init early_parse_etr(char *p)
363 {
364 	if (strncmp(p, "off", 3) == 0)
365 		etr_port0_online = etr_port1_online = 0;
366 	else if (strncmp(p, "port0", 5) == 0)
367 		etr_port0_online = 1;
368 	else if (strncmp(p, "port1", 5) == 0)
369 		etr_port1_online = 1;
370 	else if (strncmp(p, "on", 2) == 0)
371 		etr_port0_online = etr_port1_online = 1;
372 	return 0;
373 }
374 early_param("etr", early_parse_etr);
375 
376 enum etr_event {
377 	ETR_EVENT_PORT0_CHANGE,
378 	ETR_EVENT_PORT1_CHANGE,
379 	ETR_EVENT_PORT_ALERT,
380 	ETR_EVENT_SYNC_CHECK,
381 	ETR_EVENT_SWITCH_LOCAL,
382 	ETR_EVENT_UPDATE,
383 };
384 
385 enum etr_flags {
386 	ETR_FLAG_ENOSYS,
387 	ETR_FLAG_EACCES,
388 	ETR_FLAG_STEAI,
389 };
390 
391 /*
392  * Valid bit combinations of the eacr register are (x = don't care):
393  * e0 e1 dp p0 p1 ea es sl
394  *  0  0  x  0	0  0  0  0  initial, disabled state
395  *  0  0  x  0	1  1  0  0  port 1 online
396  *  0  0  x  1	0  1  0  0  port 0 online
397  *  0  0  x  1	1  1  0  0  both ports online
398  *  0  1  x  0	1  1  0  0  port 1 online and usable, ETR or PPS mode
399  *  0  1  x  0	1  1  0  1  port 1 online, usable and ETR mode
400  *  0  1  x  0	1  1  1  0  port 1 online, usable, PPS mode, in-sync
401  *  0  1  x  0	1  1  1  1  port 1 online, usable, ETR mode, in-sync
402  *  0  1  x  1	1  1  0  0  both ports online, port 1 usable
403  *  0  1  x  1	1  1  1  0  both ports online, port 1 usable, PPS mode, in-sync
404  *  0  1  x  1	1  1  1  1  both ports online, port 1 usable, ETR mode, in-sync
405  *  1  0  x  1	0  1  0  0  port 0 online and usable, ETR or PPS mode
406  *  1  0  x  1	0  1  0  1  port 0 online, usable and ETR mode
407  *  1  0  x  1	0  1  1  0  port 0 online, usable, PPS mode, in-sync
408  *  1  0  x  1	0  1  1  1  port 0 online, usable, ETR mode, in-sync
409  *  1  0  x  1	1  1  0  0  both ports online, port 0 usable
410  *  1  0  x  1	1  1  1  0  both ports online, port 0 usable, PPS mode, in-sync
411  *  1  0  x  1	1  1  1  1  both ports online, port 0 usable, ETR mode, in-sync
412  *  1  1  x  1	1  1  1  0  both ports online & usable, ETR, in-sync
413  *  1  1  x  1	1  1  1  1  both ports online & usable, ETR, in-sync
414  */
415 static struct etr_eacr etr_eacr;
416 static u64 etr_tolec;			/* time of last eacr update */
417 static unsigned long etr_flags;
418 static struct etr_aib etr_port0;
419 static int etr_port0_uptodate;
420 static struct etr_aib etr_port1;
421 static int etr_port1_uptodate;
422 static unsigned long etr_events;
423 static struct timer_list etr_timer;
424 static DEFINE_PER_CPU(atomic_t, etr_sync_word);
425 
426 static void etr_timeout(unsigned long dummy);
427 static void etr_work_fn(struct work_struct *work);
428 static DECLARE_WORK(etr_work, etr_work_fn);
429 
430 /*
431  * The etr get_clock function. It will write the current clock value
432  * to the clock pointer and return 0 if the clock is in sync with the
433  * external time source. If the clock mode is local it will return
434  * -ENOSYS and -EAGAIN if the clock is not in sync with the external
435  * reference. This function is what ETR is all about..
436  */
437 int get_sync_clock(unsigned long long *clock)
438 {
439 	atomic_t *sw_ptr;
440 	unsigned int sw0, sw1;
441 
442 	sw_ptr = &get_cpu_var(etr_sync_word);
443 	sw0 = atomic_read(sw_ptr);
444 	*clock = get_clock();
445 	sw1 = atomic_read(sw_ptr);
446 	put_cpu_var(etr_sync_sync);
447 	if (sw0 == sw1 && (sw0 & 0x80000000U))
448 		/* Success: time is in sync. */
449 		return 0;
450 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
451 		return -ENOSYS;
452 	if (test_bit(ETR_FLAG_EACCES, &etr_flags))
453 		return -EACCES;
454 	return -EAGAIN;
455 }
456 EXPORT_SYMBOL(get_sync_clock);
457 
458 /*
459  * Make get_sync_clock return -EAGAIN.
460  */
461 static void etr_disable_sync_clock(void *dummy)
462 {
463 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
464 	/*
465 	 * Clear the in-sync bit 2^31. All get_sync_clock calls will
466 	 * fail until the sync bit is turned back on. In addition
467 	 * increase the "sequence" counter to avoid the race of an
468 	 * etr event and the complete recovery against get_sync_clock.
469 	 */
470 	atomic_clear_mask(0x80000000, sw_ptr);
471 	atomic_inc(sw_ptr);
472 }
473 
474 /*
475  * Make get_sync_clock return 0 again.
476  * Needs to be called from a context disabled for preemption.
477  */
478 static void etr_enable_sync_clock(void)
479 {
480 	atomic_t *sw_ptr = &__get_cpu_var(etr_sync_word);
481 	atomic_set_mask(0x80000000, sw_ptr);
482 }
483 
484 /*
485  * Reset ETR attachment.
486  */
487 static void etr_reset(void)
488 {
489 	etr_eacr =  (struct etr_eacr) {
490 		.e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
491 		.p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
492 		.es = 0, .sl = 0 };
493 	if (etr_setr(&etr_eacr) == 0)
494 		etr_tolec = get_clock();
495 	else {
496 		set_bit(ETR_FLAG_ENOSYS, &etr_flags);
497 		if (etr_port0_online || etr_port1_online) {
498 			printk(KERN_WARNING "Running on non ETR capable "
499 			       "machine, only local mode available.\n");
500 			etr_port0_online = etr_port1_online = 0;
501 		}
502 	}
503 }
504 
505 static int __init etr_init(void)
506 {
507 	struct etr_aib aib;
508 
509 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
510 		return 0;
511 	/* Check if this machine has the steai instruction. */
512 	if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
513 		set_bit(ETR_FLAG_STEAI, &etr_flags);
514 	setup_timer(&etr_timer, etr_timeout, 0UL);
515 	if (!etr_port0_online && !etr_port1_online)
516 		set_bit(ETR_FLAG_EACCES, &etr_flags);
517 	if (etr_port0_online) {
518 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
519 		schedule_work(&etr_work);
520 	}
521 	if (etr_port1_online) {
522 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
523 		schedule_work(&etr_work);
524 	}
525 	return 0;
526 }
527 
528 arch_initcall(etr_init);
529 
530 /*
531  * Two sorts of ETR machine checks. The architecture reads:
532  * "When a machine-check niterruption occurs and if a switch-to-local or
533  *  ETR-sync-check interrupt request is pending but disabled, this pending
534  *  disabled interruption request is indicated and is cleared".
535  * Which means that we can get etr_switch_to_local events from the machine
536  * check handler although the interruption condition is disabled. Lovely..
537  */
538 
539 /*
540  * Switch to local machine check. This is called when the last usable
541  * ETR port goes inactive. After switch to local the clock is not in sync.
542  */
543 void etr_switch_to_local(void)
544 {
545 	if (!etr_eacr.sl)
546 		return;
547 	etr_disable_sync_clock(NULL);
548 	set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events);
549 	schedule_work(&etr_work);
550 }
551 
552 /*
553  * ETR sync check machine check. This is called when the ETR OTE and the
554  * local clock OTE are farther apart than the ETR sync check tolerance.
555  * After a ETR sync check the clock is not in sync. The machine check
556  * is broadcasted to all cpus at the same time.
557  */
558 void etr_sync_check(void)
559 {
560 	if (!etr_eacr.es)
561 		return;
562 	etr_disable_sync_clock(NULL);
563 	set_bit(ETR_EVENT_SYNC_CHECK, &etr_events);
564 	schedule_work(&etr_work);
565 }
566 
567 /*
568  * ETR external interrupt. There are two causes:
569  * 1) port state change, check the usability of the port
570  * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
571  *    sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
572  *    or ETR-data word 4 (edf4) has changed.
573  */
574 static void etr_ext_handler(__u16 code)
575 {
576 	struct etr_interruption_parameter *intparm =
577 		(struct etr_interruption_parameter *) &S390_lowcore.ext_params;
578 
579 	if (intparm->pc0)
580 		/* ETR port 0 state change. */
581 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
582 	if (intparm->pc1)
583 		/* ETR port 1 state change. */
584 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
585 	if (intparm->eai)
586 		/*
587 		 * ETR port alert on either port 0, 1 or both.
588 		 * Both ports are not up-to-date now.
589 		 */
590 		set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
591 	schedule_work(&etr_work);
592 }
593 
594 static void etr_timeout(unsigned long dummy)
595 {
596 	set_bit(ETR_EVENT_UPDATE, &etr_events);
597 	schedule_work(&etr_work);
598 }
599 
600 /*
601  * Check if the etr mode is pss.
602  */
603 static inline int etr_mode_is_pps(struct etr_eacr eacr)
604 {
605 	return eacr.es && !eacr.sl;
606 }
607 
608 /*
609  * Check if the etr mode is etr.
610  */
611 static inline int etr_mode_is_etr(struct etr_eacr eacr)
612 {
613 	return eacr.es && eacr.sl;
614 }
615 
616 /*
617  * Check if the port can be used for TOD synchronization.
618  * For PPS mode the port has to receive OTEs. For ETR mode
619  * the port has to receive OTEs, the ETR stepping bit has to
620  * be zero and the validity bits for data frame 1, 2, and 3
621  * have to be 1.
622  */
623 static int etr_port_valid(struct etr_aib *aib, int port)
624 {
625 	unsigned int psc;
626 
627 	/* Check that this port is receiving OTEs. */
628 	if (aib->tsp == 0)
629 		return 0;
630 
631 	psc = port ? aib->esw.psc1 : aib->esw.psc0;
632 	if (psc == etr_lpsc_pps_mode)
633 		return 1;
634 	if (psc == etr_lpsc_operational_step)
635 		return !aib->esw.y && aib->slsw.v1 &&
636 			aib->slsw.v2 && aib->slsw.v3;
637 	return 0;
638 }
639 
640 /*
641  * Check if two ports are on the same network.
642  */
643 static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
644 {
645 	// FIXME: any other fields we have to compare?
646 	return aib1->edf1.net_id == aib2->edf1.net_id;
647 }
648 
649 /*
650  * Wrapper for etr_stei that converts physical port states
651  * to logical port states to be consistent with the output
652  * of stetr (see etr_psc vs. etr_lpsc).
653  */
654 static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
655 {
656 	BUG_ON(etr_steai(aib, func) != 0);
657 	/* Convert port state to logical port state. */
658 	if (aib->esw.psc0 == 1)
659 		aib->esw.psc0 = 2;
660 	else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
661 		aib->esw.psc0 = 1;
662 	if (aib->esw.psc1 == 1)
663 		aib->esw.psc1 = 2;
664 	else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
665 		aib->esw.psc1 = 1;
666 }
667 
668 /*
669  * Check if the aib a2 is still connected to the same attachment as
670  * aib a1, the etv values differ by one and a2 is valid.
671  */
672 static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
673 {
674 	int state_a1, state_a2;
675 
676 	/* Paranoia check: e0/e1 should better be the same. */
677 	if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
678 	    a1->esw.eacr.e1 != a2->esw.eacr.e1)
679 		return 0;
680 
681 	/* Still connected to the same etr ? */
682 	state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
683 	state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
684 	if (state_a1 == etr_lpsc_operational_step) {
685 		if (state_a2 != etr_lpsc_operational_step ||
686 		    a1->edf1.net_id != a2->edf1.net_id ||
687 		    a1->edf1.etr_id != a2->edf1.etr_id ||
688 		    a1->edf1.etr_pn != a2->edf1.etr_pn)
689 			return 0;
690 	} else if (state_a2 != etr_lpsc_pps_mode)
691 		return 0;
692 
693 	/* The ETV value of a2 needs to be ETV of a1 + 1. */
694 	if (a1->edf2.etv + 1 != a2->edf2.etv)
695 		return 0;
696 
697 	if (!etr_port_valid(a2, p))
698 		return 0;
699 
700 	return 1;
701 }
702 
703 /*
704  * The time is "clock". xtime is what we think the time is.
705  * Adjust the value by a multiple of jiffies and add the delta to ntp.
706  * "delay" is an approximation how long the synchronization took. If
707  * the time correction is positive, then "delay" is subtracted from
708  * the time difference and only the remaining part is passed to ntp.
709  */
710 static void etr_adjust_time(unsigned long long clock, unsigned long long delay)
711 {
712 	unsigned long long delta, ticks;
713 	struct timex adjust;
714 
715 	/*
716 	 * We don't have to take the xtime lock because the cpu
717 	 * executing etr_adjust_time is running disabled in
718 	 * tasklet context and all other cpus are looping in
719 	 * etr_sync_cpu_start.
720 	 */
721 	if (clock > xtime_cc) {
722 		/* It is later than we thought. */
723 		delta = ticks = clock - xtime_cc;
724 		delta = ticks = (delta < delay) ? 0 : delta - delay;
725 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
726 		init_timer_cc = init_timer_cc + delta;
727 		jiffies_timer_cc = jiffies_timer_cc + delta;
728 		xtime_cc = xtime_cc + delta;
729 		adjust.offset = ticks * (1000000 / HZ);
730 	} else {
731 		/* It is earlier than we thought. */
732 		delta = ticks = xtime_cc - clock;
733 		delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
734 		init_timer_cc = init_timer_cc - delta;
735 		jiffies_timer_cc = jiffies_timer_cc - delta;
736 		xtime_cc = xtime_cc - delta;
737 		adjust.offset = -ticks * (1000000 / HZ);
738 	}
739 	if (adjust.offset != 0) {
740 		printk(KERN_NOTICE "etr: time adjusted by %li micro-seconds\n",
741 		       adjust.offset);
742 		adjust.modes = ADJ_OFFSET_SINGLESHOT;
743 		do_adjtimex(&adjust);
744 	}
745 }
746 
747 #ifdef CONFIG_SMP
748 static void etr_sync_cpu_start(void *dummy)
749 {
750 	int *in_sync = dummy;
751 
752 	etr_enable_sync_clock();
753 	/*
754 	 * This looks like a busy wait loop but it isn't. etr_sync_cpus
755 	 * is called on all other cpus while the TOD clocks is stopped.
756 	 * __udelay will stop the cpu on an enabled wait psw until the
757 	 * TOD is running again.
758 	 */
759 	while (*in_sync == 0) {
760 		__udelay(1);
761 		/*
762 		 * A different cpu changes *in_sync. Therefore use
763 		 * barrier() to force memory access.
764 		 */
765 		barrier();
766 	}
767 	if (*in_sync != 1)
768 		/* Didn't work. Clear per-cpu in sync bit again. */
769 		etr_disable_sync_clock(NULL);
770 	/*
771 	 * This round of TOD syncing is done. Set the clock comparator
772 	 * to the next tick and let the processor continue.
773 	 */
774 	setup_jiffy_timer();
775 }
776 
777 static void etr_sync_cpu_end(void *dummy)
778 {
779 }
780 #endif /* CONFIG_SMP */
781 
782 /*
783  * Sync the TOD clock using the port refered to by aibp. This port
784  * has to be enabled and the other port has to be disabled. The
785  * last eacr update has to be more than 1.6 seconds in the past.
786  */
787 static int etr_sync_clock(struct etr_aib *aib, int port)
788 {
789 	struct etr_aib *sync_port;
790 	unsigned long long clock, delay;
791 	int in_sync, follows;
792 	int rc;
793 
794 	/* Check if the current aib is adjacent to the sync port aib. */
795 	sync_port = (port == 0) ? &etr_port0 : &etr_port1;
796 	follows = etr_aib_follows(sync_port, aib, port);
797 	memcpy(sync_port, aib, sizeof(*aib));
798 	if (!follows)
799 		return -EAGAIN;
800 
801 	/*
802 	 * Catch all other cpus and make them wait until we have
803 	 * successfully synced the clock. smp_call_function will
804 	 * return after all other cpus are in etr_sync_cpu_start.
805 	 */
806 	in_sync = 0;
807 	preempt_disable();
808 	smp_call_function(etr_sync_cpu_start,&in_sync,0,0);
809 	local_irq_disable();
810 	etr_enable_sync_clock();
811 
812 	/* Set clock to next OTE. */
813 	__ctl_set_bit(14, 21);
814 	__ctl_set_bit(0, 29);
815 	clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
816 	if (set_clock(clock) == 0) {
817 		__udelay(1);	/* Wait for the clock to start. */
818 		__ctl_clear_bit(0, 29);
819 		__ctl_clear_bit(14, 21);
820 		etr_stetr(aib);
821 		/* Adjust Linux timing variables. */
822 		delay = (unsigned long long)
823 			(aib->edf2.etv - sync_port->edf2.etv) << 32;
824 		etr_adjust_time(clock, delay);
825 		setup_jiffy_timer();
826 		/* Verify that the clock is properly set. */
827 		if (!etr_aib_follows(sync_port, aib, port)) {
828 			/* Didn't work. */
829 			etr_disable_sync_clock(NULL);
830 			in_sync = -EAGAIN;
831 			rc = -EAGAIN;
832 		} else {
833 			in_sync = 1;
834 			rc = 0;
835 		}
836 	} else {
837 		/* Could not set the clock ?!? */
838 		__ctl_clear_bit(0, 29);
839 		__ctl_clear_bit(14, 21);
840 		etr_disable_sync_clock(NULL);
841 		in_sync = -EAGAIN;
842 		rc = -EAGAIN;
843 	}
844 	local_irq_enable();
845 	smp_call_function(etr_sync_cpu_end,NULL,0,0);
846 	preempt_enable();
847 	return rc;
848 }
849 
850 /*
851  * Handle the immediate effects of the different events.
852  * The port change event is used for online/offline changes.
853  */
854 static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
855 {
856 	if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
857 		eacr.es = 0;
858 	if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
859 		eacr.es = eacr.sl = 0;
860 	if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
861 		etr_port0_uptodate = etr_port1_uptodate = 0;
862 
863 	if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
864 		if (eacr.e0)
865 			/*
866 			 * Port change of an enabled port. We have to
867 			 * assume that this can have caused an stepping
868 			 * port switch.
869 			 */
870 			etr_tolec = get_clock();
871 		eacr.p0 = etr_port0_online;
872 		if (!eacr.p0)
873 			eacr.e0 = 0;
874 		etr_port0_uptodate = 0;
875 	}
876 	if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
877 		if (eacr.e1)
878 			/*
879 			 * Port change of an enabled port. We have to
880 			 * assume that this can have caused an stepping
881 			 * port switch.
882 			 */
883 			etr_tolec = get_clock();
884 		eacr.p1 = etr_port1_online;
885 		if (!eacr.p1)
886 			eacr.e1 = 0;
887 		etr_port1_uptodate = 0;
888 	}
889 	clear_bit(ETR_EVENT_UPDATE, &etr_events);
890 	return eacr;
891 }
892 
893 /*
894  * Set up a timer that expires after the etr_tolec + 1.6 seconds if
895  * one of the ports needs an update.
896  */
897 static void etr_set_tolec_timeout(unsigned long long now)
898 {
899 	unsigned long micros;
900 
901 	if ((!etr_eacr.p0 || etr_port0_uptodate) &&
902 	    (!etr_eacr.p1 || etr_port1_uptodate))
903 		return;
904 	micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
905 	micros = (micros > 1600000) ? 0 : 1600000 - micros;
906 	mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
907 }
908 
909 /*
910  * Set up a time that expires after 1/2 second.
911  */
912 static void etr_set_sync_timeout(void)
913 {
914 	mod_timer(&etr_timer, jiffies + HZ/2);
915 }
916 
917 /*
918  * Update the aib information for one or both ports.
919  */
920 static struct etr_eacr etr_handle_update(struct etr_aib *aib,
921 					 struct etr_eacr eacr)
922 {
923 	/* With both ports disabled the aib information is useless. */
924 	if (!eacr.e0 && !eacr.e1)
925 		return eacr;
926 
927 	/* Update port0 or port1 with aib stored in etr_work_fn. */
928 	if (aib->esw.q == 0) {
929 		/* Information for port 0 stored. */
930 		if (eacr.p0 && !etr_port0_uptodate) {
931 			etr_port0 = *aib;
932 			if (etr_port0_online)
933 				etr_port0_uptodate = 1;
934 		}
935 	} else {
936 		/* Information for port 1 stored. */
937 		if (eacr.p1 && !etr_port1_uptodate) {
938 			etr_port1 = *aib;
939 			if (etr_port0_online)
940 				etr_port1_uptodate = 1;
941 		}
942 	}
943 
944 	/*
945 	 * Do not try to get the alternate port aib if the clock
946 	 * is not in sync yet.
947 	 */
948 	if (!eacr.es)
949 		return eacr;
950 
951 	/*
952 	 * If steai is available we can get the information about
953 	 * the other port immediately. If only stetr is available the
954 	 * data-port bit toggle has to be used.
955 	 */
956 	if (test_bit(ETR_FLAG_STEAI, &etr_flags)) {
957 		if (eacr.p0 && !etr_port0_uptodate) {
958 			etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
959 			etr_port0_uptodate = 1;
960 		}
961 		if (eacr.p1 && !etr_port1_uptodate) {
962 			etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
963 			etr_port1_uptodate = 1;
964 		}
965 	} else {
966 		/*
967 		 * One port was updated above, if the other
968 		 * port is not uptodate toggle dp bit.
969 		 */
970 		if ((eacr.p0 && !etr_port0_uptodate) ||
971 		    (eacr.p1 && !etr_port1_uptodate))
972 			eacr.dp ^= 1;
973 		else
974 			eacr.dp = 0;
975 	}
976 	return eacr;
977 }
978 
979 /*
980  * Write new etr control register if it differs from the current one.
981  * Return 1 if etr_tolec has been updated as well.
982  */
983 static void etr_update_eacr(struct etr_eacr eacr)
984 {
985 	int dp_changed;
986 
987 	if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
988 		/* No change, return. */
989 		return;
990 	/*
991 	 * The disable of an active port of the change of the data port
992 	 * bit can/will cause a change in the data port.
993 	 */
994 	dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
995 		(etr_eacr.dp ^ eacr.dp) != 0;
996 	etr_eacr = eacr;
997 	etr_setr(&etr_eacr);
998 	if (dp_changed)
999 		etr_tolec = get_clock();
1000 }
1001 
1002 /*
1003  * ETR tasklet. In this function you'll find the main logic. In
1004  * particular this is the only function that calls etr_update_eacr(),
1005  * it "controls" the etr control register.
1006  */
1007 static void etr_work_fn(struct work_struct *work)
1008 {
1009 	unsigned long long now;
1010 	struct etr_eacr eacr;
1011 	struct etr_aib aib;
1012 	int sync_port;
1013 
1014 	/* Create working copy of etr_eacr. */
1015 	eacr = etr_eacr;
1016 
1017 	/* Check for the different events and their immediate effects. */
1018 	eacr = etr_handle_events(eacr);
1019 
1020 	/* Check if ETR is supposed to be active. */
1021 	eacr.ea = eacr.p0 || eacr.p1;
1022 	if (!eacr.ea) {
1023 		/* Both ports offline. Reset everything. */
1024 		eacr.dp = eacr.es = eacr.sl = 0;
1025 		on_each_cpu(etr_disable_sync_clock, NULL, 0, 1);
1026 		del_timer_sync(&etr_timer);
1027 		etr_update_eacr(eacr);
1028 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1029 		return;
1030 	}
1031 
1032 	/* Store aib to get the current ETR status word. */
1033 	BUG_ON(etr_stetr(&aib) != 0);
1034 	etr_port0.esw = etr_port1.esw = aib.esw;	/* Copy status word. */
1035 	now = get_clock();
1036 
1037 	/*
1038 	 * Update the port information if the last stepping port change
1039 	 * or data port change is older than 1.6 seconds.
1040 	 */
1041 	if (now >= etr_tolec + (1600000 << 12))
1042 		eacr = etr_handle_update(&aib, eacr);
1043 
1044 	/*
1045 	 * Select ports to enable. The prefered synchronization mode is PPS.
1046 	 * If a port can be enabled depends on a number of things:
1047 	 * 1) The port needs to be online and uptodate. A port is not
1048 	 *    disabled just because it is not uptodate, but it is only
1049 	 *    enabled if it is uptodate.
1050 	 * 2) The port needs to have the same mode (pps / etr).
1051 	 * 3) The port needs to be usable -> etr_port_valid() == 1
1052 	 * 4) To enable the second port the clock needs to be in sync.
1053 	 * 5) If both ports are useable and are ETR ports, the network id
1054 	 *    has to be the same.
1055 	 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1056 	 */
1057 	if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
1058 		eacr.sl = 0;
1059 		eacr.e0 = 1;
1060 		if (!etr_mode_is_pps(etr_eacr))
1061 			eacr.es = 0;
1062 		if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
1063 			eacr.e1 = 0;
1064 		// FIXME: uptodate checks ?
1065 		else if (etr_port0_uptodate && etr_port1_uptodate)
1066 			eacr.e1 = 1;
1067 		sync_port = (etr_port0_uptodate &&
1068 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1069 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1070 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
1071 		eacr.sl = 0;
1072 		eacr.e0 = 0;
1073 		eacr.e1 = 1;
1074 		if (!etr_mode_is_pps(etr_eacr))
1075 			eacr.es = 0;
1076 		sync_port = (etr_port1_uptodate &&
1077 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1078 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1079 	} else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
1080 		eacr.sl = 1;
1081 		eacr.e0 = 1;
1082 		if (!etr_mode_is_etr(etr_eacr))
1083 			eacr.es = 0;
1084 		if (!eacr.es || !eacr.p1 ||
1085 		    aib.esw.psc1 != etr_lpsc_operational_alt)
1086 			eacr.e1 = 0;
1087 		else if (etr_port0_uptodate && etr_port1_uptodate &&
1088 			 etr_compare_network(&etr_port0, &etr_port1))
1089 			eacr.e1 = 1;
1090 		sync_port = (etr_port0_uptodate &&
1091 			     etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1092 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1093 	} else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
1094 		eacr.sl = 1;
1095 		eacr.e0 = 0;
1096 		eacr.e1 = 1;
1097 		if (!etr_mode_is_etr(etr_eacr))
1098 			eacr.es = 0;
1099 		sync_port = (etr_port1_uptodate &&
1100 			     etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1101 		clear_bit(ETR_FLAG_EACCES, &etr_flags);
1102 	} else {
1103 		/* Both ports not usable. */
1104 		eacr.es = eacr.sl = 0;
1105 		sync_port = -1;
1106 		set_bit(ETR_FLAG_EACCES, &etr_flags);
1107 	}
1108 
1109 	/*
1110 	 * If the clock is in sync just update the eacr and return.
1111 	 * If there is no valid sync port wait for a port update.
1112 	 */
1113 	if (eacr.es || sync_port < 0) {
1114 		etr_update_eacr(eacr);
1115 		etr_set_tolec_timeout(now);
1116 		return;
1117 	}
1118 
1119 	/*
1120 	 * Prepare control register for clock syncing
1121 	 * (reset data port bit, set sync check control.
1122 	 */
1123 	eacr.dp = 0;
1124 	eacr.es = 1;
1125 
1126 	/*
1127 	 * Update eacr and try to synchronize the clock. If the update
1128 	 * of eacr caused a stepping port switch (or if we have to
1129 	 * assume that a stepping port switch has occured) or the
1130 	 * clock syncing failed, reset the sync check control bit
1131 	 * and set up a timer to try again after 0.5 seconds
1132 	 */
1133 	etr_update_eacr(eacr);
1134 	if (now < etr_tolec + (1600000 << 12) ||
1135 	    etr_sync_clock(&aib, sync_port) != 0) {
1136 		/* Sync failed. Try again in 1/2 second. */
1137 		eacr.es = 0;
1138 		etr_update_eacr(eacr);
1139 		etr_set_sync_timeout();
1140 	} else
1141 		etr_set_tolec_timeout(now);
1142 }
1143 
1144 /*
1145  * Sysfs interface functions
1146  */
1147 static struct sysdev_class etr_sysclass = {
1148 	.name	= "etr",
1149 };
1150 
1151 static struct sys_device etr_port0_dev = {
1152 	.id	= 0,
1153 	.cls	= &etr_sysclass,
1154 };
1155 
1156 static struct sys_device etr_port1_dev = {
1157 	.id	= 1,
1158 	.cls	= &etr_sysclass,
1159 };
1160 
1161 /*
1162  * ETR class attributes
1163  */
1164 static ssize_t etr_stepping_port_show(struct sysdev_class *class, char *buf)
1165 {
1166 	return sprintf(buf, "%i\n", etr_port0.esw.p);
1167 }
1168 
1169 static SYSDEV_CLASS_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
1170 
1171 static ssize_t etr_stepping_mode_show(struct sysdev_class *class, char *buf)
1172 {
1173 	char *mode_str;
1174 
1175 	if (etr_mode_is_pps(etr_eacr))
1176 		mode_str = "pps";
1177 	else if (etr_mode_is_etr(etr_eacr))
1178 		mode_str = "etr";
1179 	else
1180 		mode_str = "local";
1181 	return sprintf(buf, "%s\n", mode_str);
1182 }
1183 
1184 static SYSDEV_CLASS_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
1185 
1186 /*
1187  * ETR port attributes
1188  */
1189 static inline struct etr_aib *etr_aib_from_dev(struct sys_device *dev)
1190 {
1191 	if (dev == &etr_port0_dev)
1192 		return etr_port0_online ? &etr_port0 : NULL;
1193 	else
1194 		return etr_port1_online ? &etr_port1 : NULL;
1195 }
1196 
1197 static ssize_t etr_online_show(struct sys_device *dev, char *buf)
1198 {
1199 	unsigned int online;
1200 
1201 	online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
1202 	return sprintf(buf, "%i\n", online);
1203 }
1204 
1205 static ssize_t etr_online_store(struct sys_device *dev,
1206 			      const char *buf, size_t count)
1207 {
1208 	unsigned int value;
1209 
1210 	value = simple_strtoul(buf, NULL, 0);
1211 	if (value != 0 && value != 1)
1212 		return -EINVAL;
1213 	if (test_bit(ETR_FLAG_ENOSYS, &etr_flags))
1214 		return -ENOSYS;
1215 	if (dev == &etr_port0_dev) {
1216 		if (etr_port0_online == value)
1217 			return count;	/* Nothing to do. */
1218 		etr_port0_online = value;
1219 		set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
1220 		schedule_work(&etr_work);
1221 	} else {
1222 		if (etr_port1_online == value)
1223 			return count;	/* Nothing to do. */
1224 		etr_port1_online = value;
1225 		set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
1226 		schedule_work(&etr_work);
1227 	}
1228 	return count;
1229 }
1230 
1231 static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
1232 
1233 static ssize_t etr_stepping_control_show(struct sys_device *dev, char *buf)
1234 {
1235 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1236 		       etr_eacr.e0 : etr_eacr.e1);
1237 }
1238 
1239 static SYSDEV_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
1240 
1241 static ssize_t etr_mode_code_show(struct sys_device *dev, char *buf)
1242 {
1243 	if (!etr_port0_online && !etr_port1_online)
1244 		/* Status word is not uptodate if both ports are offline. */
1245 		return -ENODATA;
1246 	return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1247 		       etr_port0.esw.psc0 : etr_port0.esw.psc1);
1248 }
1249 
1250 static SYSDEV_ATTR(state_code, 0400, etr_mode_code_show, NULL);
1251 
1252 static ssize_t etr_untuned_show(struct sys_device *dev, char *buf)
1253 {
1254 	struct etr_aib *aib = etr_aib_from_dev(dev);
1255 
1256 	if (!aib || !aib->slsw.v1)
1257 		return -ENODATA;
1258 	return sprintf(buf, "%i\n", aib->edf1.u);
1259 }
1260 
1261 static SYSDEV_ATTR(untuned, 0400, etr_untuned_show, NULL);
1262 
1263 static ssize_t etr_network_id_show(struct sys_device *dev, char *buf)
1264 {
1265 	struct etr_aib *aib = etr_aib_from_dev(dev);
1266 
1267 	if (!aib || !aib->slsw.v1)
1268 		return -ENODATA;
1269 	return sprintf(buf, "%i\n", aib->edf1.net_id);
1270 }
1271 
1272 static SYSDEV_ATTR(network, 0400, etr_network_id_show, NULL);
1273 
1274 static ssize_t etr_id_show(struct sys_device *dev, char *buf)
1275 {
1276 	struct etr_aib *aib = etr_aib_from_dev(dev);
1277 
1278 	if (!aib || !aib->slsw.v1)
1279 		return -ENODATA;
1280 	return sprintf(buf, "%i\n", aib->edf1.etr_id);
1281 }
1282 
1283 static SYSDEV_ATTR(id, 0400, etr_id_show, NULL);
1284 
1285 static ssize_t etr_port_number_show(struct sys_device *dev, char *buf)
1286 {
1287 	struct etr_aib *aib = etr_aib_from_dev(dev);
1288 
1289 	if (!aib || !aib->slsw.v1)
1290 		return -ENODATA;
1291 	return sprintf(buf, "%i\n", aib->edf1.etr_pn);
1292 }
1293 
1294 static SYSDEV_ATTR(port, 0400, etr_port_number_show, NULL);
1295 
1296 static ssize_t etr_coupled_show(struct sys_device *dev, char *buf)
1297 {
1298 	struct etr_aib *aib = etr_aib_from_dev(dev);
1299 
1300 	if (!aib || !aib->slsw.v3)
1301 		return -ENODATA;
1302 	return sprintf(buf, "%i\n", aib->edf3.c);
1303 }
1304 
1305 static SYSDEV_ATTR(coupled, 0400, etr_coupled_show, NULL);
1306 
1307 static ssize_t etr_local_time_show(struct sys_device *dev, char *buf)
1308 {
1309 	struct etr_aib *aib = etr_aib_from_dev(dev);
1310 
1311 	if (!aib || !aib->slsw.v3)
1312 		return -ENODATA;
1313 	return sprintf(buf, "%i\n", aib->edf3.blto);
1314 }
1315 
1316 static SYSDEV_ATTR(local_time, 0400, etr_local_time_show, NULL);
1317 
1318 static ssize_t etr_utc_offset_show(struct sys_device *dev, char *buf)
1319 {
1320 	struct etr_aib *aib = etr_aib_from_dev(dev);
1321 
1322 	if (!aib || !aib->slsw.v3)
1323 		return -ENODATA;
1324 	return sprintf(buf, "%i\n", aib->edf3.buo);
1325 }
1326 
1327 static SYSDEV_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
1328 
1329 static struct sysdev_attribute *etr_port_attributes[] = {
1330 	&attr_online,
1331 	&attr_stepping_control,
1332 	&attr_state_code,
1333 	&attr_untuned,
1334 	&attr_network,
1335 	&attr_id,
1336 	&attr_port,
1337 	&attr_coupled,
1338 	&attr_local_time,
1339 	&attr_utc_offset,
1340 	NULL
1341 };
1342 
1343 static int __init etr_register_port(struct sys_device *dev)
1344 {
1345 	struct sysdev_attribute **attr;
1346 	int rc;
1347 
1348 	rc = sysdev_register(dev);
1349 	if (rc)
1350 		goto out;
1351 	for (attr = etr_port_attributes; *attr; attr++) {
1352 		rc = sysdev_create_file(dev, *attr);
1353 		if (rc)
1354 			goto out_unreg;
1355 	}
1356 	return 0;
1357 out_unreg:
1358 	for (; attr >= etr_port_attributes; attr--)
1359 		sysdev_remove_file(dev, *attr);
1360 	sysdev_unregister(dev);
1361 out:
1362 	return rc;
1363 }
1364 
1365 static void __init etr_unregister_port(struct sys_device *dev)
1366 {
1367 	struct sysdev_attribute **attr;
1368 
1369 	for (attr = etr_port_attributes; *attr; attr++)
1370 		sysdev_remove_file(dev, *attr);
1371 	sysdev_unregister(dev);
1372 }
1373 
1374 static int __init etr_init_sysfs(void)
1375 {
1376 	int rc;
1377 
1378 	rc = sysdev_class_register(&etr_sysclass);
1379 	if (rc)
1380 		goto out;
1381 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_port);
1382 	if (rc)
1383 		goto out_unreg_class;
1384 	rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_mode);
1385 	if (rc)
1386 		goto out_remove_stepping_port;
1387 	rc = etr_register_port(&etr_port0_dev);
1388 	if (rc)
1389 		goto out_remove_stepping_mode;
1390 	rc = etr_register_port(&etr_port1_dev);
1391 	if (rc)
1392 		goto out_remove_port0;
1393 	return 0;
1394 
1395 out_remove_port0:
1396 	etr_unregister_port(&etr_port0_dev);
1397 out_remove_stepping_mode:
1398 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_mode);
1399 out_remove_stepping_port:
1400 	sysdev_class_remove_file(&etr_sysclass, &attr_stepping_port);
1401 out_unreg_class:
1402 	sysdev_class_unregister(&etr_sysclass);
1403 out:
1404 	return rc;
1405 }
1406 
1407 device_initcall(etr_init_sysfs);
1408