xref: /linux/drivers/acpi/proc.c (revision 8ec3b8432e4fe8d452f88f1ed9a3450e715bb797)
1 #include <linux/proc_fs.h>
2 #include <linux/seq_file.h>
3 #include <linux/suspend.h>
4 #include <linux/bcd.h>
5 #include <asm/uaccess.h>
6 
7 #include <acpi/acpi_bus.h>
8 #include <acpi/acpi_drivers.h>
9 
10 #ifdef CONFIG_X86
11 #include <linux/mc146818rtc.h>
12 #endif
13 
14 #include "sleep.h"
15 
16 #define _COMPONENT		ACPI_SYSTEM_COMPONENT
17 
18 /*
19  * this file provides support for:
20  * /proc/acpi/alarm
21  * /proc/acpi/wakeup
22  */
23 
24 ACPI_MODULE_NAME("sleep")
25 
26 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
27 /* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
28 #else
29 #define	HAVE_ACPI_LEGACY_ALARM
30 #endif
31 
32 #ifdef	HAVE_ACPI_LEGACY_ALARM
33 
34 static u32 cmos_bcd_read(int offset, int rtc_control);
35 
36 static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
37 {
38 	u32 sec, min, hr;
39 	u32 day, mo, yr, cent = 0;
40 	u32 today = 0;
41 	unsigned char rtc_control = 0;
42 	unsigned long flags;
43 
44 	spin_lock_irqsave(&rtc_lock, flags);
45 
46 	rtc_control = CMOS_READ(RTC_CONTROL);
47 	sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
48 	min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
49 	hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
50 
51 	/* If we ever get an FACP with proper values... */
52 	if (acpi_gbl_FADT.day_alarm) {
53 		/* ACPI spec: only low 6 its should be cared */
54 		day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
55 		if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
56 			day = bcd2bin(day);
57 	} else
58 		day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
59 	if (acpi_gbl_FADT.month_alarm)
60 		mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
61 	else {
62 		mo = cmos_bcd_read(RTC_MONTH, rtc_control);
63 		today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
64 	}
65 	if (acpi_gbl_FADT.century)
66 		cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
67 
68 	yr = cmos_bcd_read(RTC_YEAR, rtc_control);
69 
70 	spin_unlock_irqrestore(&rtc_lock, flags);
71 
72 	/* we're trusting the FADT (see above) */
73 	if (!acpi_gbl_FADT.century)
74 		/* If we're not trusting the FADT, we should at least make it
75 		 * right for _this_ century... ehm, what is _this_ century?
76 		 *
77 		 * TBD:
78 		 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
79 		 *        which we can trust to determine the century correctly. Atom
80 		 *        watch driver would be nice, too...
81 		 *
82 		 *  if that has not happened, change for first release in 2050:
83 		 *        if (yr<50)
84 		 *                yr += 2100;
85 		 *        else
86 		 *                yr += 2000;   // current line of code
87 		 *
88 		 *  if that has not happened either, please do on 2099/12/31:23:59:59
89 		 *        s/2000/2100
90 		 *
91 		 */
92 		yr += 2000;
93 	else
94 		yr += cent * 100;
95 
96 	/*
97 	 * Show correct dates for alarms up to a month into the future.
98 	 * This solves issues for nearly all situations with the common
99 	 * 30-day alarm clocks in PC hardware.
100 	 */
101 	if (day < today) {
102 		if (mo < 12) {
103 			mo += 1;
104 		} else {
105 			mo = 1;
106 			yr += 1;
107 		}
108 	}
109 
110 	seq_printf(seq, "%4.4u-", yr);
111 	(mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
112 	(day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
113 	(hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
114 	(min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
115 	(sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);
116 
117 	return 0;
118 }
119 
120 static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
121 {
122 	return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
123 }
124 
125 static int get_date_field(char **p, u32 * value)
126 {
127 	char *next = NULL;
128 	char *string_end = NULL;
129 	int result = -EINVAL;
130 
131 	/*
132 	 * Try to find delimeter, only to insert null.  The end of the
133 	 * string won't have one, but is still valid.
134 	 */
135 	if (*p == NULL)
136 		return result;
137 
138 	next = strpbrk(*p, "- :");
139 	if (next)
140 		*next++ = '\0';
141 
142 	*value = simple_strtoul(*p, &string_end, 10);
143 
144 	/* Signal success if we got a good digit */
145 	if (string_end != *p)
146 		result = 0;
147 
148 	if (next)
149 		*p = next;
150 	else
151 		*p = NULL;
152 
153 	return result;
154 }
155 
156 /* Read a possibly BCD register, always return binary */
157 static u32 cmos_bcd_read(int offset, int rtc_control)
158 {
159 	u32 val = CMOS_READ(offset);
160 	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
161 		val = bcd2bin(val);
162 	return val;
163 }
164 
165 /* Write binary value into possibly BCD register */
166 static void cmos_bcd_write(u32 val, int offset, int rtc_control)
167 {
168 	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
169 		val = bin2bcd(val);
170 	CMOS_WRITE(val, offset);
171 }
172 
173 static ssize_t
174 acpi_system_write_alarm(struct file *file,
175 			const char __user * buffer, size_t count, loff_t * ppos)
176 {
177 	int result = 0;
178 	char alarm_string[30] = { '\0' };
179 	char *p = alarm_string;
180 	u32 sec, min, hr, day, mo, yr;
181 	int adjust = 0;
182 	unsigned char rtc_control = 0;
183 
184 	if (count > sizeof(alarm_string) - 1)
185 		return -EINVAL;
186 
187 	if (copy_from_user(alarm_string, buffer, count))
188 		return -EFAULT;
189 
190 	alarm_string[count] = '\0';
191 
192 	/* check for time adjustment */
193 	if (alarm_string[0] == '+') {
194 		p++;
195 		adjust = 1;
196 	}
197 
198 	if ((result = get_date_field(&p, &yr)))
199 		goto end;
200 	if ((result = get_date_field(&p, &mo)))
201 		goto end;
202 	if ((result = get_date_field(&p, &day)))
203 		goto end;
204 	if ((result = get_date_field(&p, &hr)))
205 		goto end;
206 	if ((result = get_date_field(&p, &min)))
207 		goto end;
208 	if ((result = get_date_field(&p, &sec)))
209 		goto end;
210 
211 	spin_lock_irq(&rtc_lock);
212 
213 	rtc_control = CMOS_READ(RTC_CONTROL);
214 
215 	if (adjust) {
216 		yr += cmos_bcd_read(RTC_YEAR, rtc_control);
217 		mo += cmos_bcd_read(RTC_MONTH, rtc_control);
218 		day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
219 		hr += cmos_bcd_read(RTC_HOURS, rtc_control);
220 		min += cmos_bcd_read(RTC_MINUTES, rtc_control);
221 		sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
222 	}
223 
224 	spin_unlock_irq(&rtc_lock);
225 
226 	if (sec > 59) {
227 		min += sec/60;
228 		sec = sec%60;
229 	}
230 	if (min > 59) {
231 		hr += min/60;
232 		min = min%60;
233 	}
234 	if (hr > 23) {
235 		day += hr/24;
236 		hr = hr%24;
237 	}
238 	if (day > 31) {
239 		mo += day/32;
240 		day = day%32;
241 	}
242 	if (mo > 12) {
243 		yr += mo/13;
244 		mo = mo%13;
245 	}
246 
247 	spin_lock_irq(&rtc_lock);
248 	/*
249 	 * Disable alarm interrupt before setting alarm timer or else
250 	 * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
251 	 */
252 	rtc_control &= ~RTC_AIE;
253 	CMOS_WRITE(rtc_control, RTC_CONTROL);
254 	CMOS_READ(RTC_INTR_FLAGS);
255 
256 	/* write the fields the rtc knows about */
257 	cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
258 	cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
259 	cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);
260 
261 	/*
262 	 * If the system supports an enhanced alarm it will have non-zero
263 	 * offsets into the CMOS RAM here -- which for some reason are pointing
264 	 * to the RTC area of memory.
265 	 */
266 	if (acpi_gbl_FADT.day_alarm)
267 		cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
268 	if (acpi_gbl_FADT.month_alarm)
269 		cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
270 	if (acpi_gbl_FADT.century) {
271 		if (adjust)
272 			yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
273 		cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
274 	}
275 	/* enable the rtc alarm interrupt */
276 	rtc_control |= RTC_AIE;
277 	CMOS_WRITE(rtc_control, RTC_CONTROL);
278 	CMOS_READ(RTC_INTR_FLAGS);
279 
280 	spin_unlock_irq(&rtc_lock);
281 
282 	acpi_clear_event(ACPI_EVENT_RTC);
283 	acpi_enable_event(ACPI_EVENT_RTC, 0);
284 
285 	*ppos += count;
286 
287 	result = 0;
288       end:
289 	return result ? result : count;
290 }
291 #endif				/* HAVE_ACPI_LEGACY_ALARM */
292 
293 static int
294 acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
295 {
296 	struct list_head *node, *next;
297 
298 	seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");
299 
300 	mutex_lock(&acpi_device_lock);
301 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
302 		struct acpi_device *dev =
303 		    container_of(node, struct acpi_device, wakeup_list);
304 		struct device *ldev;
305 
306 		if (!dev->wakeup.flags.valid)
307 			continue;
308 
309 		ldev = acpi_get_physical_device(dev->handle);
310 		seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
311 			   dev->pnp.bus_id,
312 			   (u32) dev->wakeup.sleep_state,
313 			   dev->wakeup.flags.run_wake ? '*' : ' ',
314 			   (device_may_wakeup(&dev->dev)
315 			     || (ldev && device_may_wakeup(ldev))) ?
316 			       "enabled" : "disabled");
317 		if (ldev)
318 			seq_printf(seq, "%s:%s",
319 				   ldev->bus ? ldev->bus->name : "no-bus",
320 				   dev_name(ldev));
321 		seq_printf(seq, "\n");
322 		put_device(ldev);
323 
324 	}
325 	mutex_unlock(&acpi_device_lock);
326 	return 0;
327 }
328 
329 static void physical_device_enable_wakeup(struct acpi_device *adev)
330 {
331 	struct device *dev = acpi_get_physical_device(adev->handle);
332 
333 	if (dev && device_can_wakeup(dev)) {
334 		bool enable = !device_may_wakeup(dev);
335 		device_set_wakeup_enable(dev, enable);
336 	}
337 }
338 
339 static ssize_t
340 acpi_system_write_wakeup_device(struct file *file,
341 				const char __user * buffer,
342 				size_t count, loff_t * ppos)
343 {
344 	struct list_head *node, *next;
345 	char strbuf[5];
346 	char str[5] = "";
347 	unsigned int len = count;
348 
349 	if (len > 4)
350 		len = 4;
351 	if (len < 0)
352 		return -EFAULT;
353 
354 	if (copy_from_user(strbuf, buffer, len))
355 		return -EFAULT;
356 	strbuf[len] = '\0';
357 	sscanf(strbuf, "%s", str);
358 
359 	mutex_lock(&acpi_device_lock);
360 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
361 		struct acpi_device *dev =
362 		    container_of(node, struct acpi_device, wakeup_list);
363 		if (!dev->wakeup.flags.valid)
364 			continue;
365 
366 		if (!strncmp(dev->pnp.bus_id, str, 4)) {
367 			if (device_can_wakeup(&dev->dev)) {
368 				bool enable = !device_may_wakeup(&dev->dev);
369 				device_set_wakeup_enable(&dev->dev, enable);
370 			} else {
371 				physical_device_enable_wakeup(dev);
372 			}
373 			break;
374 		}
375 	}
376 	mutex_unlock(&acpi_device_lock);
377 	return count;
378 }
379 
380 static int
381 acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
382 {
383 	return single_open(file, acpi_system_wakeup_device_seq_show,
384 			   PDE(inode)->data);
385 }
386 
387 static const struct file_operations acpi_system_wakeup_device_fops = {
388 	.owner = THIS_MODULE,
389 	.open = acpi_system_wakeup_device_open_fs,
390 	.read = seq_read,
391 	.write = acpi_system_write_wakeup_device,
392 	.llseek = seq_lseek,
393 	.release = single_release,
394 };
395 
396 #ifdef	HAVE_ACPI_LEGACY_ALARM
397 static const struct file_operations acpi_system_alarm_fops = {
398 	.owner = THIS_MODULE,
399 	.open = acpi_system_alarm_open_fs,
400 	.read = seq_read,
401 	.write = acpi_system_write_alarm,
402 	.llseek = seq_lseek,
403 	.release = single_release,
404 };
405 
406 static u32 rtc_handler(void *context)
407 {
408 	acpi_clear_event(ACPI_EVENT_RTC);
409 	acpi_disable_event(ACPI_EVENT_RTC, 0);
410 
411 	return ACPI_INTERRUPT_HANDLED;
412 }
413 #endif				/* HAVE_ACPI_LEGACY_ALARM */
414 
415 int __init acpi_sleep_proc_init(void)
416 {
417 #ifdef	HAVE_ACPI_LEGACY_ALARM
418 	/* 'alarm' [R/W] */
419 	proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
420 		    acpi_root_dir, &acpi_system_alarm_fops);
421 
422 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
423 	/*
424 	 * Disable the RTC event after installing RTC handler.
425 	 * Only when RTC alarm is set will it be enabled.
426 	 */
427 	acpi_clear_event(ACPI_EVENT_RTC);
428 	acpi_disable_event(ACPI_EVENT_RTC, 0);
429 #endif				/* HAVE_ACPI_LEGACY_ALARM */
430 
431 	/* 'wakeup device' [R/W] */
432 	proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
433 		    acpi_root_dir, &acpi_system_wakeup_device_fops);
434 
435 	return 0;
436 }
437