xref: /openbmc/linux/drivers/acpi/proc.c (revision 95e9fd10)
1 #include <linux/proc_fs.h>
2 #include <linux/seq_file.h>
3 #include <linux/export.h>
4 #include <linux/suspend.h>
5 #include <linux/bcd.h>
6 #include <asm/uaccess.h>
7 
8 #include <acpi/acpi_bus.h>
9 #include <acpi/acpi_drivers.h>
10 
11 #ifdef CONFIG_X86
12 #include <linux/mc146818rtc.h>
13 #endif
14 
15 #include "sleep.h"
16 
17 #define _COMPONENT		ACPI_SYSTEM_COMPONENT
18 
19 /*
20  * this file provides support for:
21  * /proc/acpi/alarm
22  * /proc/acpi/wakeup
23  */
24 
25 ACPI_MODULE_NAME("sleep")
26 
27 #if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || !defined(CONFIG_X86)
28 /* use /sys/class/rtc/rtcX/wakealarm instead; it's not ACPI-specific */
29 #else
30 #define	HAVE_ACPI_LEGACY_ALARM
31 #endif
32 
33 #ifdef	HAVE_ACPI_LEGACY_ALARM
34 
35 static u32 cmos_bcd_read(int offset, int rtc_control);
36 
37 static int acpi_system_alarm_seq_show(struct seq_file *seq, void *offset)
38 {
39 	u32 sec, min, hr;
40 	u32 day, mo, yr, cent = 0;
41 	u32 today = 0;
42 	unsigned char rtc_control = 0;
43 	unsigned long flags;
44 
45 	spin_lock_irqsave(&rtc_lock, flags);
46 
47 	rtc_control = CMOS_READ(RTC_CONTROL);
48 	sec = cmos_bcd_read(RTC_SECONDS_ALARM, rtc_control);
49 	min = cmos_bcd_read(RTC_MINUTES_ALARM, rtc_control);
50 	hr = cmos_bcd_read(RTC_HOURS_ALARM, rtc_control);
51 
52 	/* If we ever get an FACP with proper values... */
53 	if (acpi_gbl_FADT.day_alarm) {
54 		/* ACPI spec: only low 6 its should be cared */
55 		day = CMOS_READ(acpi_gbl_FADT.day_alarm) & 0x3F;
56 		if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
57 			day = bcd2bin(day);
58 	} else
59 		day = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
60 	if (acpi_gbl_FADT.month_alarm)
61 		mo = cmos_bcd_read(acpi_gbl_FADT.month_alarm, rtc_control);
62 	else {
63 		mo = cmos_bcd_read(RTC_MONTH, rtc_control);
64 		today = cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
65 	}
66 	if (acpi_gbl_FADT.century)
67 		cent = cmos_bcd_read(acpi_gbl_FADT.century, rtc_control);
68 
69 	yr = cmos_bcd_read(RTC_YEAR, rtc_control);
70 
71 	spin_unlock_irqrestore(&rtc_lock, flags);
72 
73 	/* we're trusting the FADT (see above) */
74 	if (!acpi_gbl_FADT.century)
75 		/* If we're not trusting the FADT, we should at least make it
76 		 * right for _this_ century... ehm, what is _this_ century?
77 		 *
78 		 * TBD:
79 		 *  ASAP: find piece of code in the kernel, e.g. star tracker driver,
80 		 *        which we can trust to determine the century correctly. Atom
81 		 *        watch driver would be nice, too...
82 		 *
83 		 *  if that has not happened, change for first release in 2050:
84 		 *        if (yr<50)
85 		 *                yr += 2100;
86 		 *        else
87 		 *                yr += 2000;   // current line of code
88 		 *
89 		 *  if that has not happened either, please do on 2099/12/31:23:59:59
90 		 *        s/2000/2100
91 		 *
92 		 */
93 		yr += 2000;
94 	else
95 		yr += cent * 100;
96 
97 	/*
98 	 * Show correct dates for alarms up to a month into the future.
99 	 * This solves issues for nearly all situations with the common
100 	 * 30-day alarm clocks in PC hardware.
101 	 */
102 	if (day < today) {
103 		if (mo < 12) {
104 			mo += 1;
105 		} else {
106 			mo = 1;
107 			yr += 1;
108 		}
109 	}
110 
111 	seq_printf(seq, "%4.4u-", yr);
112 	(mo > 12) ? seq_puts(seq, "**-") : seq_printf(seq, "%2.2u-", mo);
113 	(day > 31) ? seq_puts(seq, "** ") : seq_printf(seq, "%2.2u ", day);
114 	(hr > 23) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", hr);
115 	(min > 59) ? seq_puts(seq, "**:") : seq_printf(seq, "%2.2u:", min);
116 	(sec > 59) ? seq_puts(seq, "**\n") : seq_printf(seq, "%2.2u\n", sec);
117 
118 	return 0;
119 }
120 
121 static int acpi_system_alarm_open_fs(struct inode *inode, struct file *file)
122 {
123 	return single_open(file, acpi_system_alarm_seq_show, PDE(inode)->data);
124 }
125 
126 static int get_date_field(char **p, u32 * value)
127 {
128 	char *next = NULL;
129 	char *string_end = NULL;
130 	int result = -EINVAL;
131 
132 	/*
133 	 * Try to find delimeter, only to insert null.  The end of the
134 	 * string won't have one, but is still valid.
135 	 */
136 	if (*p == NULL)
137 		return result;
138 
139 	next = strpbrk(*p, "- :");
140 	if (next)
141 		*next++ = '\0';
142 
143 	*value = simple_strtoul(*p, &string_end, 10);
144 
145 	/* Signal success if we got a good digit */
146 	if (string_end != *p)
147 		result = 0;
148 
149 	if (next)
150 		*p = next;
151 	else
152 		*p = NULL;
153 
154 	return result;
155 }
156 
157 /* Read a possibly BCD register, always return binary */
158 static u32 cmos_bcd_read(int offset, int rtc_control)
159 {
160 	u32 val = CMOS_READ(offset);
161 	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
162 		val = bcd2bin(val);
163 	return val;
164 }
165 
166 /* Write binary value into possibly BCD register */
167 static void cmos_bcd_write(u32 val, int offset, int rtc_control)
168 {
169 	if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
170 		val = bin2bcd(val);
171 	CMOS_WRITE(val, offset);
172 }
173 
174 static ssize_t
175 acpi_system_write_alarm(struct file *file,
176 			const char __user * buffer, size_t count, loff_t * ppos)
177 {
178 	int result = 0;
179 	char alarm_string[30] = { '\0' };
180 	char *p = alarm_string;
181 	u32 sec, min, hr, day, mo, yr;
182 	int adjust = 0;
183 	unsigned char rtc_control = 0;
184 
185 	if (count > sizeof(alarm_string) - 1)
186 		return -EINVAL;
187 
188 	if (copy_from_user(alarm_string, buffer, count))
189 		return -EFAULT;
190 
191 	alarm_string[count] = '\0';
192 
193 	/* check for time adjustment */
194 	if (alarm_string[0] == '+') {
195 		p++;
196 		adjust = 1;
197 	}
198 
199 	if ((result = get_date_field(&p, &yr)))
200 		goto end;
201 	if ((result = get_date_field(&p, &mo)))
202 		goto end;
203 	if ((result = get_date_field(&p, &day)))
204 		goto end;
205 	if ((result = get_date_field(&p, &hr)))
206 		goto end;
207 	if ((result = get_date_field(&p, &min)))
208 		goto end;
209 	if ((result = get_date_field(&p, &sec)))
210 		goto end;
211 
212 	spin_lock_irq(&rtc_lock);
213 
214 	rtc_control = CMOS_READ(RTC_CONTROL);
215 
216 	if (adjust) {
217 		yr += cmos_bcd_read(RTC_YEAR, rtc_control);
218 		mo += cmos_bcd_read(RTC_MONTH, rtc_control);
219 		day += cmos_bcd_read(RTC_DAY_OF_MONTH, rtc_control);
220 		hr += cmos_bcd_read(RTC_HOURS, rtc_control);
221 		min += cmos_bcd_read(RTC_MINUTES, rtc_control);
222 		sec += cmos_bcd_read(RTC_SECONDS, rtc_control);
223 	}
224 
225 	spin_unlock_irq(&rtc_lock);
226 
227 	if (sec > 59) {
228 		min += sec/60;
229 		sec = sec%60;
230 	}
231 	if (min > 59) {
232 		hr += min/60;
233 		min = min%60;
234 	}
235 	if (hr > 23) {
236 		day += hr/24;
237 		hr = hr%24;
238 	}
239 	if (day > 31) {
240 		mo += day/32;
241 		day = day%32;
242 	}
243 	if (mo > 12) {
244 		yr += mo/13;
245 		mo = mo%13;
246 	}
247 
248 	spin_lock_irq(&rtc_lock);
249 	/*
250 	 * Disable alarm interrupt before setting alarm timer or else
251 	 * when ACPI_EVENT_RTC is enabled, a spurious ACPI interrupt occurs
252 	 */
253 	rtc_control &= ~RTC_AIE;
254 	CMOS_WRITE(rtc_control, RTC_CONTROL);
255 	CMOS_READ(RTC_INTR_FLAGS);
256 
257 	/* write the fields the rtc knows about */
258 	cmos_bcd_write(hr, RTC_HOURS_ALARM, rtc_control);
259 	cmos_bcd_write(min, RTC_MINUTES_ALARM, rtc_control);
260 	cmos_bcd_write(sec, RTC_SECONDS_ALARM, rtc_control);
261 
262 	/*
263 	 * If the system supports an enhanced alarm it will have non-zero
264 	 * offsets into the CMOS RAM here -- which for some reason are pointing
265 	 * to the RTC area of memory.
266 	 */
267 	if (acpi_gbl_FADT.day_alarm)
268 		cmos_bcd_write(day, acpi_gbl_FADT.day_alarm, rtc_control);
269 	if (acpi_gbl_FADT.month_alarm)
270 		cmos_bcd_write(mo, acpi_gbl_FADT.month_alarm, rtc_control);
271 	if (acpi_gbl_FADT.century) {
272 		if (adjust)
273 			yr += cmos_bcd_read(acpi_gbl_FADT.century, rtc_control) * 100;
274 		cmos_bcd_write(yr / 100, acpi_gbl_FADT.century, rtc_control);
275 	}
276 	/* enable the rtc alarm interrupt */
277 	rtc_control |= RTC_AIE;
278 	CMOS_WRITE(rtc_control, RTC_CONTROL);
279 	CMOS_READ(RTC_INTR_FLAGS);
280 
281 	spin_unlock_irq(&rtc_lock);
282 
283 	acpi_clear_event(ACPI_EVENT_RTC);
284 	acpi_enable_event(ACPI_EVENT_RTC, 0);
285 
286 	*ppos += count;
287 
288 	result = 0;
289       end:
290 	return result ? result : count;
291 }
292 #endif				/* HAVE_ACPI_LEGACY_ALARM */
293 
294 static int
295 acpi_system_wakeup_device_seq_show(struct seq_file *seq, void *offset)
296 {
297 	struct list_head *node, *next;
298 
299 	seq_printf(seq, "Device\tS-state\t  Status   Sysfs node\n");
300 
301 	mutex_lock(&acpi_device_lock);
302 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
303 		struct acpi_device *dev =
304 		    container_of(node, struct acpi_device, wakeup_list);
305 		struct device *ldev;
306 
307 		if (!dev->wakeup.flags.valid)
308 			continue;
309 
310 		ldev = acpi_get_physical_device(dev->handle);
311 		seq_printf(seq, "%s\t  S%d\t%c%-8s  ",
312 			   dev->pnp.bus_id,
313 			   (u32) dev->wakeup.sleep_state,
314 			   dev->wakeup.flags.run_wake ? '*' : ' ',
315 			   (device_may_wakeup(&dev->dev)
316 			     || (ldev && device_may_wakeup(ldev))) ?
317 			       "enabled" : "disabled");
318 		if (ldev)
319 			seq_printf(seq, "%s:%s",
320 				   ldev->bus ? ldev->bus->name : "no-bus",
321 				   dev_name(ldev));
322 		seq_printf(seq, "\n");
323 		put_device(ldev);
324 
325 	}
326 	mutex_unlock(&acpi_device_lock);
327 	return 0;
328 }
329 
330 static void physical_device_enable_wakeup(struct acpi_device *adev)
331 {
332 	struct device *dev = acpi_get_physical_device(adev->handle);
333 
334 	if (dev && device_can_wakeup(dev)) {
335 		bool enable = !device_may_wakeup(dev);
336 		device_set_wakeup_enable(dev, enable);
337 	}
338 }
339 
340 static ssize_t
341 acpi_system_write_wakeup_device(struct file *file,
342 				const char __user * buffer,
343 				size_t count, loff_t * ppos)
344 {
345 	struct list_head *node, *next;
346 	char strbuf[5];
347 	char str[5] = "";
348 	unsigned int len = count;
349 
350 	if (len > 4)
351 		len = 4;
352 	if (len < 0)
353 		return -EFAULT;
354 
355 	if (copy_from_user(strbuf, buffer, len))
356 		return -EFAULT;
357 	strbuf[len] = '\0';
358 	sscanf(strbuf, "%s", str);
359 
360 	mutex_lock(&acpi_device_lock);
361 	list_for_each_safe(node, next, &acpi_wakeup_device_list) {
362 		struct acpi_device *dev =
363 		    container_of(node, struct acpi_device, wakeup_list);
364 		if (!dev->wakeup.flags.valid)
365 			continue;
366 
367 		if (!strncmp(dev->pnp.bus_id, str, 4)) {
368 			if (device_can_wakeup(&dev->dev)) {
369 				bool enable = !device_may_wakeup(&dev->dev);
370 				device_set_wakeup_enable(&dev->dev, enable);
371 			} else {
372 				physical_device_enable_wakeup(dev);
373 			}
374 			break;
375 		}
376 	}
377 	mutex_unlock(&acpi_device_lock);
378 	return count;
379 }
380 
381 static int
382 acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
383 {
384 	return single_open(file, acpi_system_wakeup_device_seq_show,
385 			   PDE(inode)->data);
386 }
387 
388 static const struct file_operations acpi_system_wakeup_device_fops = {
389 	.owner = THIS_MODULE,
390 	.open = acpi_system_wakeup_device_open_fs,
391 	.read = seq_read,
392 	.write = acpi_system_write_wakeup_device,
393 	.llseek = seq_lseek,
394 	.release = single_release,
395 };
396 
397 #ifdef	HAVE_ACPI_LEGACY_ALARM
398 static const struct file_operations acpi_system_alarm_fops = {
399 	.owner = THIS_MODULE,
400 	.open = acpi_system_alarm_open_fs,
401 	.read = seq_read,
402 	.write = acpi_system_write_alarm,
403 	.llseek = seq_lseek,
404 	.release = single_release,
405 };
406 
407 static u32 rtc_handler(void *context)
408 {
409 	acpi_clear_event(ACPI_EVENT_RTC);
410 	acpi_disable_event(ACPI_EVENT_RTC, 0);
411 
412 	return ACPI_INTERRUPT_HANDLED;
413 }
414 #endif				/* HAVE_ACPI_LEGACY_ALARM */
415 
416 int __init acpi_sleep_proc_init(void)
417 {
418 #ifdef	HAVE_ACPI_LEGACY_ALARM
419 	/* 'alarm' [R/W] */
420 	proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
421 		    acpi_root_dir, &acpi_system_alarm_fops);
422 
423 	acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
424 	/*
425 	 * Disable the RTC event after installing RTC handler.
426 	 * Only when RTC alarm is set will it be enabled.
427 	 */
428 	acpi_clear_event(ACPI_EVENT_RTC);
429 	acpi_disable_event(ACPI_EVENT_RTC, 0);
430 #endif				/* HAVE_ACPI_LEGACY_ALARM */
431 
432 	/* 'wakeup device' [R/W] */
433 	proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
434 		    acpi_root_dir, &acpi_system_wakeup_device_fops);
435 
436 	return 0;
437 }
438