blob: d060a06ce05b67c7351a73e3a76bbd34444eb54c [file] [log] [blame]
David Brownell7be2c7c2007-02-10 01:46:02 -08001/*
2 * RTC class driver for "CMOS RTC": PCs, ACPI, etc
3 *
4 * Copyright (C) 1996 Paul Gortmaker (drivers/char/rtc.c)
5 * Copyright (C) 2006 David Brownell (convert to new framework)
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13/*
14 * The original "cmos clock" chip was an MC146818 chip, now obsolete.
15 * That defined the register interface now provided by all PCs, some
16 * non-PC systems, and incorporated into ACPI. Modern PC chipsets
17 * integrate an MC146818 clone in their southbridge, and boards use
18 * that instead of discrete clones like the DS12887 or M48T86. There
19 * are also clones that connect using the LPC bus.
20 *
21 * That register API is also used directly by various other drivers
22 * (notably for integrated NVRAM), infrastructure (x86 has code to
23 * bypass the RTC framework, directly reading the RTC during boot
24 * and updating minutes/seconds for systems using NTP synch) and
25 * utilities (like userspace 'hwclock', if no /dev node exists).
26 *
27 * So **ALL** calls to CMOS_READ and CMOS_WRITE must be done with
28 * interrupts disabled, holding the global rtc_lock, to exclude those
29 * other drivers and utilities on correctly configured systems.
30 */
31#include <linux/kernel.h>
32#include <linux/module.h>
33#include <linux/init.h>
34#include <linux/interrupt.h>
35#include <linux/spinlock.h>
36#include <linux/platform_device.h>
37#include <linux/mod_devicetable.h>
38
Bernhard Walle9d8af782008-02-06 01:38:52 -080039#ifdef CONFIG_HPET_EMULATE_RTC
40#include <asm/hpet.h>
41#endif
42
David Brownell7be2c7c2007-02-10 01:46:02 -080043/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */
44#include <asm-generic/rtc.h>
45
Bernhard Walle9d8af782008-02-06 01:38:52 -080046#ifndef CONFIG_HPET_EMULATE_RTC
47#define is_hpet_enabled() 0
48#define hpet_set_alarm_time(hrs, min, sec) do { } while (0)
49#define hpet_set_periodic_freq(arg) 0
50#define hpet_mask_rtc_irq_bit(arg) do { } while (0)
51#define hpet_set_rtc_irq_bit(arg) do { } while (0)
52#define hpet_rtc_timer_init() do { } while (0)
53#define hpet_register_irq_handler(h) 0
54#define hpet_unregister_irq_handler(h) do { } while (0)
55extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
56#endif
David Brownell7be2c7c2007-02-10 01:46:02 -080057
58struct cmos_rtc {
59 struct rtc_device *rtc;
60 struct device *dev;
61 int irq;
62 struct resource *iomem;
63
David Brownell87ac84f2007-05-08 00:34:00 -070064 void (*wake_on)(struct device *);
65 void (*wake_off)(struct device *);
66
67 u8 enabled_wake;
David Brownell7be2c7c2007-02-10 01:46:02 -080068 u8 suspend_ctrl;
69
70 /* newer hardware extends the original register set */
71 u8 day_alrm;
72 u8 mon_alrm;
73 u8 century;
74};
75
76/* both platform and pnp busses use negative numbers for invalid irqs */
77#define is_valid_irq(n) ((n) >= 0)
78
79static const char driver_name[] = "rtc_cmos";
80
David Brownellbcd9b892007-04-01 23:49:47 -070081/* The RTC_INTR register may have e.g. RTC_PF set even if RTC_PIE is clear;
82 * always mask it against the irq enable bits in RTC_CONTROL. Bit values
83 * are the same: PF==PIE, AF=AIE, UF=UIE; so RTC_IRQMASK works with both.
84 */
85#define RTC_IRQMASK (RTC_PF | RTC_AF | RTC_UF)
86
87static inline int is_intr(u8 rtc_intr)
88{
89 if (!(rtc_intr & RTC_IRQF))
90 return 0;
91 return rtc_intr & RTC_IRQMASK;
92}
93
David Brownell7be2c7c2007-02-10 01:46:02 -080094/*----------------------------------------------------------------*/
95
96static int cmos_read_time(struct device *dev, struct rtc_time *t)
97{
98 /* REVISIT: if the clock has a "century" register, use
99 * that instead of the heuristic in get_rtc_time().
100 * That'll make Y3K compatility (year > 2070) easy!
101 */
102 get_rtc_time(t);
103 return 0;
104}
105
106static int cmos_set_time(struct device *dev, struct rtc_time *t)
107{
108 /* REVISIT: set the "century" register if available
109 *
110 * NOTE: this ignores the issue whereby updating the seconds
111 * takes effect exactly 500ms after we write the register.
112 * (Also queueing and other delays before we get this far.)
113 */
114 return set_rtc_time(t);
115}
116
117static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
118{
119 struct cmos_rtc *cmos = dev_get_drvdata(dev);
120 unsigned char rtc_control;
121
122 if (!is_valid_irq(cmos->irq))
123 return -EIO;
124
125 /* Basic alarms only support hour, minute, and seconds fields.
126 * Some also support day and month, for alarms up to a year in
127 * the future.
128 */
129 t->time.tm_mday = -1;
130 t->time.tm_mon = -1;
131
132 spin_lock_irq(&rtc_lock);
133 t->time.tm_sec = CMOS_READ(RTC_SECONDS_ALARM);
134 t->time.tm_min = CMOS_READ(RTC_MINUTES_ALARM);
135 t->time.tm_hour = CMOS_READ(RTC_HOURS_ALARM);
136
137 if (cmos->day_alrm) {
Mark Lord615bb292007-11-03 22:04:03 -0400138 /* ignore upper bits on readback per ACPI spec */
139 t->time.tm_mday = CMOS_READ(cmos->day_alrm) & 0x3f;
David Brownell7be2c7c2007-02-10 01:46:02 -0800140 if (!t->time.tm_mday)
141 t->time.tm_mday = -1;
142
143 if (cmos->mon_alrm) {
144 t->time.tm_mon = CMOS_READ(cmos->mon_alrm);
145 if (!t->time.tm_mon)
146 t->time.tm_mon = -1;
147 }
148 }
149
150 rtc_control = CMOS_READ(RTC_CONTROL);
151 spin_unlock_irq(&rtc_lock);
152
153 /* REVISIT this assumes PC style usage: always BCD */
154
155 if (((unsigned)t->time.tm_sec) < 0x60)
156 t->time.tm_sec = BCD2BIN(t->time.tm_sec);
157 else
158 t->time.tm_sec = -1;
159 if (((unsigned)t->time.tm_min) < 0x60)
160 t->time.tm_min = BCD2BIN(t->time.tm_min);
161 else
162 t->time.tm_min = -1;
163 if (((unsigned)t->time.tm_hour) < 0x24)
164 t->time.tm_hour = BCD2BIN(t->time.tm_hour);
165 else
166 t->time.tm_hour = -1;
167
168 if (cmos->day_alrm) {
169 if (((unsigned)t->time.tm_mday) <= 0x31)
170 t->time.tm_mday = BCD2BIN(t->time.tm_mday);
171 else
172 t->time.tm_mday = -1;
173 if (cmos->mon_alrm) {
174 if (((unsigned)t->time.tm_mon) <= 0x12)
175 t->time.tm_mon = BCD2BIN(t->time.tm_mon) - 1;
176 else
177 t->time.tm_mon = -1;
178 }
179 }
180 t->time.tm_year = -1;
181
182 t->enabled = !!(rtc_control & RTC_AIE);
183 t->pending = 0;
184
185 return 0;
186}
187
188static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
189{
190 struct cmos_rtc *cmos = dev_get_drvdata(dev);
191 unsigned char mon, mday, hrs, min, sec;
192 unsigned char rtc_control, rtc_intr;
193
194 if (!is_valid_irq(cmos->irq))
195 return -EIO;
196
197 /* REVISIT this assumes PC style usage: always BCD */
198
199 /* Writing 0xff means "don't care" or "match all". */
200
Zhao Yakui2b653e02008-04-15 14:34:29 -0700201 mon = t->time.tm_mon + 1;
202 mon = (mon <= 12) ? BIN2BCD(mon) : 0xff;
David Brownell7be2c7c2007-02-10 01:46:02 -0800203
204 mday = t->time.tm_mday;
205 mday = (mday >= 1 && mday <= 31) ? BIN2BCD(mday) : 0xff;
206
207 hrs = t->time.tm_hour;
208 hrs = (hrs < 24) ? BIN2BCD(hrs) : 0xff;
209
210 min = t->time.tm_min;
211 min = (min < 60) ? BIN2BCD(min) : 0xff;
212
213 sec = t->time.tm_sec;
214 sec = (sec < 60) ? BIN2BCD(sec) : 0xff;
215
Bernhard Walle9d8af782008-02-06 01:38:52 -0800216 hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);
David Brownell7be2c7c2007-02-10 01:46:02 -0800217 spin_lock_irq(&rtc_lock);
218
219 /* next rtc irq must not be from previous alarm setting */
220 rtc_control = CMOS_READ(RTC_CONTROL);
221 rtc_control &= ~RTC_AIE;
222 CMOS_WRITE(rtc_control, RTC_CONTROL);
223 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
David Brownellbcd9b892007-04-01 23:49:47 -0700224 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
225 if (is_intr(rtc_intr))
David Brownellab6a2d72007-05-08 00:33:30 -0700226 rtc_update_irq(cmos->rtc, 1, rtc_intr);
David Brownell7be2c7c2007-02-10 01:46:02 -0800227
228 /* update alarm */
229 CMOS_WRITE(hrs, RTC_HOURS_ALARM);
230 CMOS_WRITE(min, RTC_MINUTES_ALARM);
231 CMOS_WRITE(sec, RTC_SECONDS_ALARM);
232
233 /* the system may support an "enhanced" alarm */
234 if (cmos->day_alrm) {
235 CMOS_WRITE(mday, cmos->day_alrm);
236 if (cmos->mon_alrm)
237 CMOS_WRITE(mon, cmos->mon_alrm);
238 }
239
240 if (t->enabled) {
241 rtc_control |= RTC_AIE;
242 CMOS_WRITE(rtc_control, RTC_CONTROL);
243 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
David Brownellbcd9b892007-04-01 23:49:47 -0700244 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
245 if (is_intr(rtc_intr))
David Brownellab6a2d72007-05-08 00:33:30 -0700246 rtc_update_irq(cmos->rtc, 1, rtc_intr);
David Brownell7be2c7c2007-02-10 01:46:02 -0800247 }
248
249 spin_unlock_irq(&rtc_lock);
250
251 return 0;
252}
253
Alessandro Zummo57deb522007-07-19 01:49:21 -0700254static int cmos_irq_set_freq(struct device *dev, int freq)
David Brownell7be2c7c2007-02-10 01:46:02 -0800255{
256 struct cmos_rtc *cmos = dev_get_drvdata(dev);
257 int f;
258 unsigned long flags;
259
260 if (!is_valid_irq(cmos->irq))
261 return -ENXIO;
262
263 /* 0 = no irqs; 1 = 2^15 Hz ... 15 = 2^0 Hz */
264 f = ffs(freq);
David Brownell97144c62007-10-16 01:28:16 -0700265 if (f-- > 16)
266 return -EINVAL;
267 f = 16 - f;
David Brownell7be2c7c2007-02-10 01:46:02 -0800268
269 spin_lock_irqsave(&rtc_lock, flags);
Bernhard Walle9d8af782008-02-06 01:38:52 -0800270 if (!hpet_set_periodic_freq(freq))
271 CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
David Brownell7be2c7c2007-02-10 01:46:02 -0800272 spin_unlock_irqrestore(&rtc_lock, flags);
273
274 return 0;
275}
276
Alessandro Zummo57deb522007-07-19 01:49:21 -0700277static int cmos_irq_set_state(struct device *dev, int enabled)
278{
279 struct cmos_rtc *cmos = dev_get_drvdata(dev);
280 unsigned char rtc_control, rtc_intr;
281 unsigned long flags;
282
283 if (!is_valid_irq(cmos->irq))
284 return -ENXIO;
285
286 spin_lock_irqsave(&rtc_lock, flags);
287 rtc_control = CMOS_READ(RTC_CONTROL);
288
289 if (enabled)
290 rtc_control |= RTC_PIE;
291 else
292 rtc_control &= ~RTC_PIE;
293
294 CMOS_WRITE(rtc_control, RTC_CONTROL);
295
296 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
297 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
298 if (is_intr(rtc_intr))
299 rtc_update_irq(cmos->rtc, 1, rtc_intr);
300
301 spin_unlock_irqrestore(&rtc_lock, flags);
302 return 0;
303}
304
David Brownell7be2c7c2007-02-10 01:46:02 -0800305#if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE)
306
307static int
308cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
309{
310 struct cmos_rtc *cmos = dev_get_drvdata(dev);
311 unsigned char rtc_control, rtc_intr;
312 unsigned long flags;
313
314 switch (cmd) {
315 case RTC_AIE_OFF:
316 case RTC_AIE_ON:
317 case RTC_UIE_OFF:
318 case RTC_UIE_ON:
319 case RTC_PIE_OFF:
320 case RTC_PIE_ON:
321 if (!is_valid_irq(cmos->irq))
322 return -EINVAL;
323 break;
324 default:
325 return -ENOIOCTLCMD;
326 }
327
328 spin_lock_irqsave(&rtc_lock, flags);
329 rtc_control = CMOS_READ(RTC_CONTROL);
330 switch (cmd) {
331 case RTC_AIE_OFF: /* alarm off */
332 rtc_control &= ~RTC_AIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800333 hpet_mask_rtc_irq_bit(RTC_AIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800334 break;
335 case RTC_AIE_ON: /* alarm on */
336 rtc_control |= RTC_AIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800337 hpet_set_rtc_irq_bit(RTC_AIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800338 break;
339 case RTC_UIE_OFF: /* update off */
340 rtc_control &= ~RTC_UIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800341 hpet_mask_rtc_irq_bit(RTC_UIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800342 break;
343 case RTC_UIE_ON: /* update on */
344 rtc_control |= RTC_UIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800345 hpet_set_rtc_irq_bit(RTC_UIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800346 break;
347 case RTC_PIE_OFF: /* periodic off */
348 rtc_control &= ~RTC_PIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800349 hpet_mask_rtc_irq_bit(RTC_PIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800350 break;
351 case RTC_PIE_ON: /* periodic on */
352 rtc_control |= RTC_PIE;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800353 hpet_set_rtc_irq_bit(RTC_PIE);
David Brownell7be2c7c2007-02-10 01:46:02 -0800354 break;
355 }
Bernhard Walle9d8af782008-02-06 01:38:52 -0800356 if (!is_hpet_enabled())
357 CMOS_WRITE(rtc_control, RTC_CONTROL);
358
David Brownell7be2c7c2007-02-10 01:46:02 -0800359 rtc_intr = CMOS_READ(RTC_INTR_FLAGS);
David Brownellbcd9b892007-04-01 23:49:47 -0700360 rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
361 if (is_intr(rtc_intr))
David Brownellab6a2d72007-05-08 00:33:30 -0700362 rtc_update_irq(cmos->rtc, 1, rtc_intr);
Bernhard Walle9d8af782008-02-06 01:38:52 -0800363
David Brownell7be2c7c2007-02-10 01:46:02 -0800364 spin_unlock_irqrestore(&rtc_lock, flags);
365 return 0;
366}
367
368#else
369#define cmos_rtc_ioctl NULL
370#endif
371
372#if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE)
373
374static int cmos_procfs(struct device *dev, struct seq_file *seq)
375{
376 struct cmos_rtc *cmos = dev_get_drvdata(dev);
377 unsigned char rtc_control, valid;
378
379 spin_lock_irq(&rtc_lock);
380 rtc_control = CMOS_READ(RTC_CONTROL);
381 valid = CMOS_READ(RTC_VALID);
382 spin_unlock_irq(&rtc_lock);
383
384 /* NOTE: at least ICH6 reports battery status using a different
385 * (non-RTC) bit; and SQWE is ignored on many current systems.
386 */
387 return seq_printf(seq,
388 "periodic_IRQ\t: %s\n"
389 "update_IRQ\t: %s\n"
David Brownellc8626a12008-02-23 15:23:44 -0800390 "HPET_emulated\t: %s\n"
David Brownell7be2c7c2007-02-10 01:46:02 -0800391 // "square_wave\t: %s\n"
392 // "BCD\t\t: %s\n"
393 "DST_enable\t: %s\n"
394 "periodic_freq\t: %d\n"
395 "batt_status\t: %s\n",
396 (rtc_control & RTC_PIE) ? "yes" : "no",
397 (rtc_control & RTC_UIE) ? "yes" : "no",
David Brownellc8626a12008-02-23 15:23:44 -0800398 is_hpet_enabled() ? "yes" : "no",
David Brownell7be2c7c2007-02-10 01:46:02 -0800399 // (rtc_control & RTC_SQWE) ? "yes" : "no",
400 // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
401 (rtc_control & RTC_DST_EN) ? "yes" : "no",
402 cmos->rtc->irq_freq,
403 (valid & RTC_VRT) ? "okay" : "dead");
404}
405
406#else
407#define cmos_procfs NULL
408#endif
409
410static const struct rtc_class_ops cmos_rtc_ops = {
411 .ioctl = cmos_rtc_ioctl,
412 .read_time = cmos_read_time,
413 .set_time = cmos_set_time,
414 .read_alarm = cmos_read_alarm,
415 .set_alarm = cmos_set_alarm,
416 .proc = cmos_procfs,
Alessandro Zummo57deb522007-07-19 01:49:21 -0700417 .irq_set_freq = cmos_irq_set_freq,
418 .irq_set_state = cmos_irq_set_state,
David Brownell7be2c7c2007-02-10 01:46:02 -0800419};
420
421/*----------------------------------------------------------------*/
422
David Brownelle07e2322008-02-06 01:38:43 -0800423/*
424 * All these chips have at least 64 bytes of address space, shared by
425 * RTC registers and NVRAM. Most of those bytes of NVRAM are used
426 * by boot firmware. Modern chips have 128 or 256 bytes.
427 */
428
429#define NVRAM_OFFSET (RTC_REG_D + 1)
430
431static ssize_t
432cmos_nvram_read(struct kobject *kobj, struct bin_attribute *attr,
433 char *buf, loff_t off, size_t count)
434{
435 int retval;
436
437 if (unlikely(off >= attr->size))
438 return 0;
439 if ((off + count) > attr->size)
440 count = attr->size - off;
441
442 spin_lock_irq(&rtc_lock);
443 for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++)
444 *buf++ = CMOS_READ(off);
445 spin_unlock_irq(&rtc_lock);
446
447 return retval;
448}
449
450static ssize_t
451cmos_nvram_write(struct kobject *kobj, struct bin_attribute *attr,
452 char *buf, loff_t off, size_t count)
453{
454 struct cmos_rtc *cmos;
455 int retval;
456
457 cmos = dev_get_drvdata(container_of(kobj, struct device, kobj));
458 if (unlikely(off >= attr->size))
459 return -EFBIG;
460 if ((off + count) > attr->size)
461 count = attr->size - off;
462
463 /* NOTE: on at least PCs and Ataris, the boot firmware uses a
464 * checksum on part of the NVRAM data. That's currently ignored
465 * here. If userspace is smart enough to know what fields of
466 * NVRAM to update, updating checksums is also part of its job.
467 */
468 spin_lock_irq(&rtc_lock);
469 for (retval = 0, off += NVRAM_OFFSET; count--; retval++, off++) {
470 /* don't trash RTC registers */
471 if (off == cmos->day_alrm
472 || off == cmos->mon_alrm
473 || off == cmos->century)
474 buf++;
475 else
476 CMOS_WRITE(*buf++, off);
477 }
478 spin_unlock_irq(&rtc_lock);
479
480 return retval;
481}
482
483static struct bin_attribute nvram = {
484 .attr = {
485 .name = "nvram",
486 .mode = S_IRUGO | S_IWUSR,
487 .owner = THIS_MODULE,
488 },
489
490 .read = cmos_nvram_read,
491 .write = cmos_nvram_write,
492 /* size gets set up later */
493};
494
495/*----------------------------------------------------------------*/
496
David Brownell7be2c7c2007-02-10 01:46:02 -0800497static struct cmos_rtc cmos_rtc;
498
499static irqreturn_t cmos_interrupt(int irq, void *p)
500{
501 u8 irqstat;
David Brownell8a0bdfd2008-02-06 01:38:45 -0800502 u8 rtc_control;
David Brownell7be2c7c2007-02-10 01:46:02 -0800503
504 spin_lock(&rtc_lock);
Bernhard Walle9d8af782008-02-06 01:38:52 -0800505 /*
506 * In this case it is HPET RTC interrupt handler
507 * calling us, with the interrupt information
508 * passed as arg1, instead of irq.
509 */
510 if (is_hpet_enabled())
511 irqstat = (unsigned long)irq & 0xF0;
512 else {
513 irqstat = CMOS_READ(RTC_INTR_FLAGS);
514 rtc_control = CMOS_READ(RTC_CONTROL);
515 irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
516 }
David Brownell8a0bdfd2008-02-06 01:38:45 -0800517
518 /* All Linux RTC alarms should be treated as if they were oneshot.
519 * Similar code may be needed in system wakeup paths, in case the
520 * alarm woke the system.
521 */
522 if (irqstat & RTC_AIE) {
Bernhard Walle9d8af782008-02-06 01:38:52 -0800523 rtc_control = CMOS_READ(RTC_CONTROL);
David Brownell8a0bdfd2008-02-06 01:38:45 -0800524 rtc_control &= ~RTC_AIE;
525 CMOS_WRITE(rtc_control, RTC_CONTROL);
526 CMOS_READ(RTC_INTR_FLAGS);
527 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800528 spin_unlock(&rtc_lock);
529
David Brownellbcd9b892007-04-01 23:49:47 -0700530 if (is_intr(irqstat)) {
David Brownell7be2c7c2007-02-10 01:46:02 -0800531 rtc_update_irq(p, 1, irqstat);
532 return IRQ_HANDLED;
533 } else
534 return IRQ_NONE;
535}
536
Marko Vrh41ac8df2007-05-08 00:34:09 -0700537#ifdef CONFIG_PNP
David Brownell7be2c7c2007-02-10 01:46:02 -0800538#define INITSECTION
539
540#else
David Brownell7be2c7c2007-02-10 01:46:02 -0800541#define INITSECTION __init
542#endif
543
544static int INITSECTION
545cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
546{
547 struct cmos_rtc_board_info *info = dev->platform_data;
548 int retval = 0;
549 unsigned char rtc_control;
David Brownelle07e2322008-02-06 01:38:43 -0800550 unsigned address_space;
David Brownell7be2c7c2007-02-10 01:46:02 -0800551
552 /* there can be only one ... */
553 if (cmos_rtc.dev)
554 return -EBUSY;
555
556 if (!ports)
557 return -ENODEV;
558
David Brownell05440df2007-10-16 01:28:21 -0700559 /* Claim I/O ports ASAP, minimizing conflict with legacy driver.
560 *
561 * REVISIT non-x86 systems may instead use memory space resources
562 * (needing ioremap etc), not i/o space resources like this ...
563 */
564 ports = request_region(ports->start,
565 ports->end + 1 - ports->start,
566 driver_name);
567 if (!ports) {
568 dev_dbg(dev, "i/o registers already in use\n");
569 return -EBUSY;
570 }
571
David Brownell7be2c7c2007-02-10 01:46:02 -0800572 cmos_rtc.irq = rtc_irq;
573 cmos_rtc.iomem = ports;
574
David Brownelle07e2322008-02-06 01:38:43 -0800575 /* Heuristic to deduce NVRAM size ... do what the legacy NVRAM
576 * driver did, but don't reject unknown configs. Old hardware
577 * won't address 128 bytes, and for now we ignore the way newer
578 * chips can address 256 bytes (using two more i/o ports).
579 */
580#if defined(CONFIG_ATARI)
581 address_space = 64;
582#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__)
583 address_space = 128;
584#else
585#warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
586 address_space = 128;
587#endif
588
David Brownell87ac84f2007-05-08 00:34:00 -0700589 /* For ACPI systems extension info comes from the FADT. On others,
590 * board specific setup provides it as appropriate. Systems where
591 * the alarm IRQ isn't automatically a wakeup IRQ (like ACPI, and
592 * some almost-clones) can provide hooks to make that behave.
David Brownelle07e2322008-02-06 01:38:43 -0800593 *
594 * Note that ACPI doesn't preclude putting these registers into
595 * "extended" areas of the chip, including some that we won't yet
596 * expect CMOS_READ and friends to handle.
David Brownell7be2c7c2007-02-10 01:46:02 -0800597 */
598 if (info) {
David Brownelle07e2322008-02-06 01:38:43 -0800599 if (info->rtc_day_alarm && info->rtc_day_alarm < 128)
600 cmos_rtc.day_alrm = info->rtc_day_alarm;
601 if (info->rtc_mon_alarm && info->rtc_mon_alarm < 128)
602 cmos_rtc.mon_alrm = info->rtc_mon_alarm;
603 if (info->rtc_century && info->rtc_century < 128)
604 cmos_rtc.century = info->rtc_century;
David Brownell87ac84f2007-05-08 00:34:00 -0700605
606 if (info->wake_on && info->wake_off) {
607 cmos_rtc.wake_on = info->wake_on;
608 cmos_rtc.wake_off = info->wake_off;
609 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800610 }
611
612 cmos_rtc.rtc = rtc_device_register(driver_name, dev,
613 &cmos_rtc_ops, THIS_MODULE);
David Brownell05440df2007-10-16 01:28:21 -0700614 if (IS_ERR(cmos_rtc.rtc)) {
615 retval = PTR_ERR(cmos_rtc.rtc);
616 goto cleanup0;
617 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800618
619 cmos_rtc.dev = dev;
620 dev_set_drvdata(dev, &cmos_rtc);
David Brownellcd966202007-05-08 00:33:40 -0700621 rename_region(ports, cmos_rtc.rtc->dev.bus_id);
David Brownell7be2c7c2007-02-10 01:46:02 -0800622
623 spin_lock_irq(&rtc_lock);
624
625 /* force periodic irq to CMOS reset default of 1024Hz;
626 *
627 * REVISIT it's been reported that at least one x86_64 ALI mobo
628 * doesn't use 32KHz here ... for portability we might need to
629 * do something about other clock frequencies.
630 */
David Brownell7be2c7c2007-02-10 01:46:02 -0800631 cmos_rtc.rtc->irq_freq = 1024;
Bernhard Walle9d8af782008-02-06 01:38:52 -0800632 if (!hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq))
633 CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);
David Brownell7be2c7c2007-02-10 01:46:02 -0800634
635 /* disable irqs.
636 *
637 * NOTE after changing RTC_xIE bits we always read INTR_FLAGS;
638 * allegedly some older rtcs need that to handle irqs properly
639 */
640 rtc_control = CMOS_READ(RTC_CONTROL);
641 rtc_control &= ~(RTC_PIE | RTC_AIE | RTC_UIE);
642 CMOS_WRITE(rtc_control, RTC_CONTROL);
643 CMOS_READ(RTC_INTR_FLAGS);
644
645 spin_unlock_irq(&rtc_lock);
646
647 /* FIXME teach the alarm code how to handle binary mode;
648 * <asm-generic/rtc.h> doesn't know 12-hour mode either.
649 */
650 if (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY))) {
651 dev_dbg(dev, "only 24-hr BCD mode supported\n");
652 retval = -ENXIO;
653 goto cleanup1;
654 }
655
Bernhard Walle9d8af782008-02-06 01:38:52 -0800656 if (is_valid_irq(rtc_irq)) {
657 irq_handler_t rtc_cmos_int_handler;
658
659 if (is_hpet_enabled()) {
660 int err;
661
662 rtc_cmos_int_handler = hpet_rtc_interrupt;
663 err = hpet_register_irq_handler(cmos_interrupt);
664 if (err != 0) {
665 printk(KERN_WARNING "hpet_register_irq_handler "
666 " failed in rtc_init().");
667 goto cleanup1;
668 }
669 } else
670 rtc_cmos_int_handler = cmos_interrupt;
671
672 retval = request_irq(rtc_irq, rtc_cmos_int_handler,
673 IRQF_DISABLED, cmos_rtc.rtc->dev.bus_id,
David Brownellab6a2d72007-05-08 00:33:30 -0700674 cmos_rtc.rtc);
Bernhard Walle9d8af782008-02-06 01:38:52 -0800675 if (retval < 0) {
676 dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);
677 goto cleanup1;
678 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800679 }
Bernhard Walle9d8af782008-02-06 01:38:52 -0800680 hpet_rtc_timer_init();
David Brownell7be2c7c2007-02-10 01:46:02 -0800681
David Brownelle07e2322008-02-06 01:38:43 -0800682 /* export at least the first block of NVRAM */
683 nvram.size = address_space - NVRAM_OFFSET;
684 retval = sysfs_create_bin_file(&dev->kobj, &nvram);
685 if (retval < 0) {
686 dev_dbg(dev, "can't create nvram file? %d\n", retval);
687 goto cleanup2;
688 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800689
690 pr_info("%s: alarms up to one %s%s\n",
David Brownellcd966202007-05-08 00:33:40 -0700691 cmos_rtc.rtc->dev.bus_id,
David Brownell7be2c7c2007-02-10 01:46:02 -0800692 is_valid_irq(rtc_irq)
693 ? (cmos_rtc.mon_alrm
694 ? "year"
695 : (cmos_rtc.day_alrm
696 ? "month" : "day"))
697 : "no",
698 cmos_rtc.century ? ", y3k" : ""
699 );
700
701 return 0;
702
David Brownelle07e2322008-02-06 01:38:43 -0800703cleanup2:
704 if (is_valid_irq(rtc_irq))
705 free_irq(rtc_irq, cmos_rtc.rtc);
David Brownell7be2c7c2007-02-10 01:46:02 -0800706cleanup1:
David Brownell05440df2007-10-16 01:28:21 -0700707 cmos_rtc.dev = NULL;
David Brownell7be2c7c2007-02-10 01:46:02 -0800708 rtc_device_unregister(cmos_rtc.rtc);
David Brownell05440df2007-10-16 01:28:21 -0700709cleanup0:
710 release_region(ports->start, ports->end + 1 - ports->start);
David Brownell7be2c7c2007-02-10 01:46:02 -0800711 return retval;
712}
713
714static void cmos_do_shutdown(void)
715{
716 unsigned char rtc_control;
717
718 spin_lock_irq(&rtc_lock);
719 rtc_control = CMOS_READ(RTC_CONTROL);
720 rtc_control &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
721 CMOS_WRITE(rtc_control, RTC_CONTROL);
722 CMOS_READ(RTC_INTR_FLAGS);
723 spin_unlock_irq(&rtc_lock);
724}
725
726static void __exit cmos_do_remove(struct device *dev)
727{
728 struct cmos_rtc *cmos = dev_get_drvdata(dev);
David Brownell05440df2007-10-16 01:28:21 -0700729 struct resource *ports;
David Brownell7be2c7c2007-02-10 01:46:02 -0800730
731 cmos_do_shutdown();
732
David Brownelle07e2322008-02-06 01:38:43 -0800733 sysfs_remove_bin_file(&dev->kobj, &nvram);
734
Bernhard Walle9d8af782008-02-06 01:38:52 -0800735 if (is_valid_irq(cmos->irq)) {
David Brownell05440df2007-10-16 01:28:21 -0700736 free_irq(cmos->irq, cmos->rtc);
Bernhard Walle9d8af782008-02-06 01:38:52 -0800737 hpet_unregister_irq_handler(cmos_interrupt);
738 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800739
David Brownell05440df2007-10-16 01:28:21 -0700740 rtc_device_unregister(cmos->rtc);
741 cmos->rtc = NULL;
David Brownell7be2c7c2007-02-10 01:46:02 -0800742
David Brownell05440df2007-10-16 01:28:21 -0700743 ports = cmos->iomem;
744 release_region(ports->start, ports->end + 1 - ports->start);
745 cmos->iomem = NULL;
746
747 cmos->dev = NULL;
David Brownell7be2c7c2007-02-10 01:46:02 -0800748 dev_set_drvdata(dev, NULL);
749}
750
751#ifdef CONFIG_PM
752
753static int cmos_suspend(struct device *dev, pm_message_t mesg)
754{
755 struct cmos_rtc *cmos = dev_get_drvdata(dev);
756 int do_wake = device_may_wakeup(dev);
David Brownellbcd9b892007-04-01 23:49:47 -0700757 unsigned char tmp;
David Brownell7be2c7c2007-02-10 01:46:02 -0800758
759 /* only the alarm might be a wakeup event source */
760 spin_lock_irq(&rtc_lock);
761 cmos->suspend_ctrl = tmp = CMOS_READ(RTC_CONTROL);
762 if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
David Brownellbcd9b892007-04-01 23:49:47 -0700763 unsigned char irqstat;
764
David Brownell7be2c7c2007-02-10 01:46:02 -0800765 if (do_wake)
766 tmp &= ~(RTC_PIE|RTC_UIE);
767 else
768 tmp &= ~(RTC_PIE|RTC_AIE|RTC_UIE);
769 CMOS_WRITE(tmp, RTC_CONTROL);
770 irqstat = CMOS_READ(RTC_INTR_FLAGS);
David Brownellbcd9b892007-04-01 23:49:47 -0700771 irqstat &= (tmp & RTC_IRQMASK) | RTC_IRQF;
772 if (is_intr(irqstat))
David Brownellab6a2d72007-05-08 00:33:30 -0700773 rtc_update_irq(cmos->rtc, 1, irqstat);
David Brownellbcd9b892007-04-01 23:49:47 -0700774 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800775 spin_unlock_irq(&rtc_lock);
776
David Brownell87ac84f2007-05-08 00:34:00 -0700777 if (tmp & RTC_AIE) {
778 cmos->enabled_wake = 1;
779 if (cmos->wake_on)
780 cmos->wake_on(dev);
781 else
782 enable_irq_wake(cmos->irq);
783 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800784
785 pr_debug("%s: suspend%s, ctrl %02x\n",
David Brownellcd966202007-05-08 00:33:40 -0700786 cmos_rtc.rtc->dev.bus_id,
David Brownell7be2c7c2007-02-10 01:46:02 -0800787 (tmp & RTC_AIE) ? ", alarm may wake" : "",
788 tmp);
789
790 return 0;
791}
792
793static int cmos_resume(struct device *dev)
794{
795 struct cmos_rtc *cmos = dev_get_drvdata(dev);
796 unsigned char tmp = cmos->suspend_ctrl;
797
David Brownell7be2c7c2007-02-10 01:46:02 -0800798 /* re-enable any irqs previously active */
799 if (tmp & (RTC_PIE|RTC_AIE|RTC_UIE)) {
800
David Brownell87ac84f2007-05-08 00:34:00 -0700801 if (cmos->enabled_wake) {
802 if (cmos->wake_off)
803 cmos->wake_off(dev);
804 else
805 disable_irq_wake(cmos->irq);
806 cmos->enabled_wake = 0;
807 }
David Brownell7be2c7c2007-02-10 01:46:02 -0800808
809 spin_lock_irq(&rtc_lock);
810 CMOS_WRITE(tmp, RTC_CONTROL);
811 tmp = CMOS_READ(RTC_INTR_FLAGS);
David Brownellbcd9b892007-04-01 23:49:47 -0700812 tmp &= (cmos->suspend_ctrl & RTC_IRQMASK) | RTC_IRQF;
813 if (is_intr(tmp))
David Brownellab6a2d72007-05-08 00:33:30 -0700814 rtc_update_irq(cmos->rtc, 1, tmp);
David Brownellbcd9b892007-04-01 23:49:47 -0700815 spin_unlock_irq(&rtc_lock);
David Brownell7be2c7c2007-02-10 01:46:02 -0800816 }
817
818 pr_debug("%s: resume, ctrl %02x\n",
David Brownellcd966202007-05-08 00:33:40 -0700819 cmos_rtc.rtc->dev.bus_id,
David Brownell7be2c7c2007-02-10 01:46:02 -0800820 cmos->suspend_ctrl);
821
822
823 return 0;
824}
825
826#else
827#define cmos_suspend NULL
828#define cmos_resume NULL
829#endif
830
831/*----------------------------------------------------------------*/
832
David Brownelle07e2322008-02-06 01:38:43 -0800833/* On non-x86 systems, a "CMOS" RTC lives most naturally on platform_bus.
834 * ACPI systems always list these as PNPACPI devices, and pre-ACPI PCs
835 * probably list them in similar PNPBIOS tables; so PNP is more common.
836 *
837 * We don't use legacy "poke at the hardware" probing. Ancient PCs that
838 * predate even PNPBIOS should set up platform_bus devices.
David Brownell7be2c7c2007-02-10 01:46:02 -0800839 */
840
Marko Vrh41ac8df2007-05-08 00:34:09 -0700841#ifdef CONFIG_PNP
David Brownell7be2c7c2007-02-10 01:46:02 -0800842
843#include <linux/pnp.h>
844
845static int __devinit
846cmos_pnp_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
847{
848 /* REVISIT paranoia argues for a shutdown notifier, since PNP
849 * drivers can't provide shutdown() methods to disable IRQs.
850 * Or better yet, fix PNP to allow those methods...
851 */
Matthew Garrett6cd8fa82007-06-01 00:46:51 -0700852 if (pnp_port_start(pnp,0) == 0x70 && !pnp_irq_valid(pnp,0))
853 /* Some machines contain a PNP entry for the RTC, but
854 * don't define the IRQ. It should always be safe to
855 * hardcode it in these cases
856 */
Bjorn Helgaas8766ad02008-04-28 16:34:27 -0600857 return cmos_do_probe(&pnp->dev,
858 pnp_get_resource(pnp, IORESOURCE_IO, 0), 8);
Matthew Garrett6cd8fa82007-06-01 00:46:51 -0700859 else
860 return cmos_do_probe(&pnp->dev,
Bjorn Helgaas8766ad02008-04-28 16:34:27 -0600861 pnp_get_resource(pnp, IORESOURCE_IO, 0),
862 pnp_irq(pnp, 0));
David Brownell7be2c7c2007-02-10 01:46:02 -0800863}
864
865static void __exit cmos_pnp_remove(struct pnp_dev *pnp)
866{
867 cmos_do_remove(&pnp->dev);
868}
869
870#ifdef CONFIG_PM
871
872static int cmos_pnp_suspend(struct pnp_dev *pnp, pm_message_t mesg)
873{
874 return cmos_suspend(&pnp->dev, mesg);
875}
876
877static int cmos_pnp_resume(struct pnp_dev *pnp)
878{
879 return cmos_resume(&pnp->dev);
880}
881
882#else
883#define cmos_pnp_suspend NULL
884#define cmos_pnp_resume NULL
885#endif
886
887
888static const struct pnp_device_id rtc_ids[] = {
889 { .id = "PNP0b00", },
890 { .id = "PNP0b01", },
891 { .id = "PNP0b02", },
892 { },
893};
894MODULE_DEVICE_TABLE(pnp, rtc_ids);
895
896static struct pnp_driver cmos_pnp_driver = {
897 .name = (char *) driver_name,
898 .id_table = rtc_ids,
899 .probe = cmos_pnp_probe,
900 .remove = __exit_p(cmos_pnp_remove),
901
902 /* flag ensures resume() gets called, and stops syslog spam */
903 .flags = PNP_DRIVER_RES_DO_NOT_CHANGE,
904 .suspend = cmos_pnp_suspend,
905 .resume = cmos_pnp_resume,
906};
907
908static int __init cmos_init(void)
909{
910 return pnp_register_driver(&cmos_pnp_driver);
911}
912module_init(cmos_init);
913
914static void __exit cmos_exit(void)
915{
916 pnp_unregister_driver(&cmos_pnp_driver);
917}
918module_exit(cmos_exit);
919
Marko Vrh41ac8df2007-05-08 00:34:09 -0700920#else /* no PNP */
David Brownell7be2c7c2007-02-10 01:46:02 -0800921
922/*----------------------------------------------------------------*/
923
Marko Vrh41ac8df2007-05-08 00:34:09 -0700924/* Platform setup should have set up an RTC device, when PNP is
David Brownellbcd9b892007-04-01 23:49:47 -0700925 * unavailable ... this could happen even on (older) PCs.
David Brownell7be2c7c2007-02-10 01:46:02 -0800926 */
927
928static int __init cmos_platform_probe(struct platform_device *pdev)
929{
930 return cmos_do_probe(&pdev->dev,
931 platform_get_resource(pdev, IORESOURCE_IO, 0),
932 platform_get_irq(pdev, 0));
933}
934
935static int __exit cmos_platform_remove(struct platform_device *pdev)
936{
937 cmos_do_remove(&pdev->dev);
938 return 0;
939}
940
941static void cmos_platform_shutdown(struct platform_device *pdev)
942{
943 cmos_do_shutdown();
944}
945
Kay Sieversad28a072008-04-10 21:29:25 -0700946/* work with hotplug and coldplug */
947MODULE_ALIAS("platform:rtc_cmos");
948
David Brownell7be2c7c2007-02-10 01:46:02 -0800949static struct platform_driver cmos_platform_driver = {
950 .remove = __exit_p(cmos_platform_remove),
951 .shutdown = cmos_platform_shutdown,
952 .driver = {
953 .name = (char *) driver_name,
954 .suspend = cmos_suspend,
955 .resume = cmos_resume,
956 }
957};
958
959static int __init cmos_init(void)
960{
961 return platform_driver_probe(&cmos_platform_driver,
962 cmos_platform_probe);
963}
964module_init(cmos_init);
965
966static void __exit cmos_exit(void)
967{
968 platform_driver_unregister(&cmos_platform_driver);
969}
970module_exit(cmos_exit);
971
972
Marko Vrh41ac8df2007-05-08 00:34:09 -0700973#endif /* !PNP */
David Brownell7be2c7c2007-02-10 01:46:02 -0800974
975MODULE_AUTHOR("David Brownell");
976MODULE_DESCRIPTION("Driver for PC-style 'CMOS' RTCs");
977MODULE_LICENSE("GPL");