drivers/acpi/proc.c

   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 }