drivers/acpi/proc.c

   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_DATA(inode));
 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 acpi_device_physical_node *entry;
 306
 307                 if (!dev->wakeup.flags.valid)
 308                         continue;
 309
 310                 seq_printf(seq, "%s\t  S%d\t",
 311                            dev->pnp.bus_id,
 312                            (u32) dev->wakeup.sleep_state);
 313
 314                 mutex_lock(&dev->physical_node_lock);
 315
 316                 if (!dev->physical_node_count) {
 317                         seq_printf(seq, "%c%-8s\n",
 318                                 dev->wakeup.flags.run_wake ? '*' : ' ',
 319                                 device_may_wakeup(&dev->dev) ?
 320                                         "enabled" : "disabled");
 321                 } else {
 322                         struct device *ldev;
 323                         list_for_each_entry(entry, &dev->physical_node_list,
 324                                         node) {
 325                                 ldev = get_device(entry->dev);
 326                                 if (!ldev)
 327                                         continue;
 328
 329                                 if (&entry->node !=
 330                                                 dev->physical_node_list.next)
 331                                         seq_printf(seq, "\t\t");
 332
 333                                 seq_printf(seq, "%c%-8s  %s:%s\n",
 334                                         dev->wakeup.flags.run_wake ? '*' : ' ',
 335                                         (device_may_wakeup(&dev->dev) ||
 336                                         (ldev && device_may_wakeup(ldev))) ?
 337                                         "enabled" : "disabled",
 338                                         ldev->bus ? ldev->bus->name :
 339                                         "no-bus", dev_name(ldev));
 340                                 put_device(ldev);
 341                         }
 342                 }
 343
 344                 mutex_unlock(&dev->physical_node_lock);
 345         }
 346         mutex_unlock(&acpi_device_lock);
 347         return 0;
 348 }
 349
 350 static void physical_device_enable_wakeup(struct acpi_device *adev)
 351 {
 352         struct acpi_device_physical_node *entry;
 353
 354         mutex_lock(&adev->physical_node_lock);
 355
 356         list_for_each_entry(entry,
 357                 &adev->physical_node_list, node)
 358                 if (entry->dev && device_can_wakeup(entry->dev)) {
 359                         bool enable = !device_may_wakeup(entry->dev);
 360                         device_set_wakeup_enable(entry->dev, enable);
 361                 }
 362
 363         mutex_unlock(&adev->physical_node_lock);
 364 }
 365
 366 static ssize_t
 367 acpi_system_write_wakeup_device(struct file *file,
 368                                 const char __user * buffer,
 369                                 size_t count, loff_t * ppos)
 370 {
 371         struct list_head *node, *next;
 372         char strbuf[5];
 373         char str[5] = "";
 374
 375         if (count > 4)
 376                 count = 4;
 377
 378         if (copy_from_user(strbuf, buffer, count))
 379                 return -EFAULT;
 380         strbuf[count] = '\0';
 381         sscanf(strbuf, "%s", str);
 382
 383         mutex_lock(&acpi_device_lock);
 384         list_for_each_safe(node, next, &acpi_wakeup_device_list) {
 385                 struct acpi_device *dev =
 386                     container_of(node, struct acpi_device, wakeup_list);
 387                 if (!dev->wakeup.flags.valid)
 388                         continue;
 389
 390                 if (!strncmp(dev->pnp.bus_id, str, 4)) {
 391                         if (device_can_wakeup(&dev->dev)) {
 392                                 bool enable = !device_may_wakeup(&dev->dev);
 393                                 device_set_wakeup_enable(&dev->dev, enable);
 394                         } else {
 395                                 physical_device_enable_wakeup(dev);
 396                         }
 397                         break;
 398                 }
 399         }
 400         mutex_unlock(&acpi_device_lock);
 401         return count;
 402 }
 403
 404 static int
 405 acpi_system_wakeup_device_open_fs(struct inode *inode, struct file *file)
 406 {
 407         return single_open(file, acpi_system_wakeup_device_seq_show,
 408                            PDE_DATA(inode));
 409 }
 410
 411 static const struct file_operations acpi_system_wakeup_device_fops = {
 412         .owner = THIS_MODULE,
 413         .open = acpi_system_wakeup_device_open_fs,
 414         .read = seq_read,
 415         .write = acpi_system_write_wakeup_device,
 416         .llseek = seq_lseek,
 417         .release = single_release,
 418 };
 419
 420 #ifdef  HAVE_ACPI_LEGACY_ALARM
 421 static const struct file_operations acpi_system_alarm_fops = {
 422         .owner = THIS_MODULE,
 423         .open = acpi_system_alarm_open_fs,
 424         .read = seq_read,
 425         .write = acpi_system_write_alarm,
 426         .llseek = seq_lseek,
 427         .release = single_release,
 428 };
 429
 430 static u32 rtc_handler(void *context)
 431 {
 432         acpi_clear_event(ACPI_EVENT_RTC);
 433         acpi_disable_event(ACPI_EVENT_RTC, 0);
 434
 435         return ACPI_INTERRUPT_HANDLED;
 436 }
 437 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 438
 439 int __init acpi_sleep_proc_init(void)
 440 {
 441 #ifdef  HAVE_ACPI_LEGACY_ALARM
 442         /* 'alarm' [R/W] */
 443         proc_create("alarm", S_IFREG | S_IRUGO | S_IWUSR,
 444                     acpi_root_dir, &acpi_system_alarm_fops);
 445
 446         acpi_install_fixed_event_handler(ACPI_EVENT_RTC, rtc_handler, NULL);
 447         /*
 448          * Disable the RTC event after installing RTC handler.
 449          * Only when RTC alarm is set will it be enabled.
 450          */
 451         acpi_clear_event(ACPI_EVENT_RTC);
 452         acpi_disable_event(ACPI_EVENT_RTC, 0);
 453 #endif                          /* HAVE_ACPI_LEGACY_ALARM */
 454
 455         /* 'wakeup device' [R/W] */
 456         proc_create("wakeup", S_IFREG | S_IRUGO | S_IWUSR,
 457                     acpi_root_dir, &acpi_system_wakeup_device_fops);
 458
 459         return 0;
 460 }