linux/include/uapi/linux/rtc.h
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   1/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
   2/*
   3 * Generic RTC interface.
   4 * This version contains the part of the user interface to the Real Time Clock
   5 * service. It is used with both the legacy mc146818 and also  EFI
   6 * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
   7 * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
   8 *
   9 * Copyright (C) 1999 Hewlett-Packard Co.
  10 * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
  11 */
  12#ifndef _UAPI_LINUX_RTC_H_
  13#define _UAPI_LINUX_RTC_H_
  14
  15#include <linux/const.h>
  16#include <linux/ioctl.h>
  17
  18/*
  19 * The struct used to pass data via the following ioctl. Similar to the
  20 * struct tm in <time.h>, but it needs to be here so that the kernel
  21 * source is self contained, allowing cross-compiles, etc. etc.
  22 */
  23
  24struct rtc_time {
  25        int tm_sec;
  26        int tm_min;
  27        int tm_hour;
  28        int tm_mday;
  29        int tm_mon;
  30        int tm_year;
  31        int tm_wday;
  32        int tm_yday;
  33        int tm_isdst;
  34};
  35
  36/*
  37 * This data structure is inspired by the EFI (v0.92) wakeup
  38 * alarm API.
  39 */
  40struct rtc_wkalrm {
  41        unsigned char enabled;  /* 0 = alarm disabled, 1 = alarm enabled */
  42        unsigned char pending;  /* 0 = alarm not pending, 1 = alarm pending */
  43        struct rtc_time time;   /* time the alarm is set to */
  44};
  45
  46/*
  47 * Data structure to control PLL correction some better RTC feature
  48 * pll_value is used to get or set current value of correction,
  49 * the rest of the struct is used to query HW capabilities.
  50 * This is modeled after the RTC used in Q40/Q60 computers but
  51 * should be sufficiently flexible for other devices
  52 *
  53 * +ve pll_value means clock will run faster by
  54 *   pll_value*pll_posmult/pll_clock
  55 * -ve pll_value means clock will run slower by
  56 *   pll_value*pll_negmult/pll_clock
  57 */
  58
  59struct rtc_pll_info {
  60        int pll_ctrl;       /* placeholder for fancier control */
  61        int pll_value;      /* get/set correction value */
  62        int pll_max;        /* max +ve (faster) adjustment value */
  63        int pll_min;        /* max -ve (slower) adjustment value */
  64        int pll_posmult;    /* factor for +ve correction */
  65        int pll_negmult;    /* factor for -ve correction */
  66        long pll_clock;     /* base PLL frequency */
  67};
  68
  69/*
  70 * ioctl calls that are permitted to the /dev/rtc interface, if
  71 * any of the RTC drivers are enabled.
  72 */
  73
  74#define RTC_AIE_ON      _IO('p', 0x01)  /* Alarm int. enable on         */
  75#define RTC_AIE_OFF     _IO('p', 0x02)  /* ... off                      */
  76#define RTC_UIE_ON      _IO('p', 0x03)  /* Update int. enable on        */
  77#define RTC_UIE_OFF     _IO('p', 0x04)  /* ... off                      */
  78#define RTC_PIE_ON      _IO('p', 0x05)  /* Periodic int. enable on      */
  79#define RTC_PIE_OFF     _IO('p', 0x06)  /* ... off                      */
  80#define RTC_WIE_ON      _IO('p', 0x0f)  /* Watchdog int. enable on      */
  81#define RTC_WIE_OFF     _IO('p', 0x10)  /* ... off                      */
  82
  83#define RTC_ALM_SET     _IOW('p', 0x07, struct rtc_time) /* Set alarm time  */
  84#define RTC_ALM_READ    _IOR('p', 0x08, struct rtc_time) /* Read alarm time */
  85#define RTC_RD_TIME     _IOR('p', 0x09, struct rtc_time) /* Read RTC time   */
  86#define RTC_SET_TIME    _IOW('p', 0x0a, struct rtc_time) /* Set RTC time    */
  87#define RTC_IRQP_READ   _IOR('p', 0x0b, unsigned long)   /* Read IRQ rate   */
  88#define RTC_IRQP_SET    _IOW('p', 0x0c, unsigned long)   /* Set IRQ rate    */
  89#define RTC_EPOCH_READ  _IOR('p', 0x0d, unsigned long)   /* Read epoch      */
  90#define RTC_EPOCH_SET   _IOW('p', 0x0e, unsigned long)   /* Set epoch       */
  91
  92#define RTC_WKALM_SET   _IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
  93#define RTC_WKALM_RD    _IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
  94
  95#define RTC_PLL_GET     _IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
  96#define RTC_PLL_SET     _IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
  97
  98#define RTC_VL_DATA_INVALID     _BITUL(0) /* Voltage too low, RTC data is invalid */
  99#define RTC_VL_BACKUP_LOW       _BITUL(1) /* Backup voltage is low */
 100#define RTC_VL_BACKUP_EMPTY     _BITUL(2) /* Backup empty or not present */
 101#define RTC_VL_ACCURACY_LOW     _BITUL(3) /* Voltage is low, RTC accuracy is reduced */
 102#define RTC_VL_BACKUP_SWITCH    _BITUL(4) /* Backup switchover happened */
 103
 104#define RTC_VL_READ     _IOR('p', 0x13, unsigned int)   /* Voltage low detection */
 105#define RTC_VL_CLR      _IO('p', 0x14)          /* Clear voltage low information */
 106
 107/* interrupt flags */
 108#define RTC_IRQF 0x80   /* Any of the following is active */
 109#define RTC_PF 0x40     /* Periodic interrupt */
 110#define RTC_AF 0x20     /* Alarm interrupt */
 111#define RTC_UF 0x10     /* Update interrupt for 1Hz RTC */
 112
 113/* feature list */
 114#define RTC_FEATURE_ALARM               0
 115#define RTC_FEATURE_ALARM_RES_MINUTE    1
 116#define RTC_FEATURE_NEED_WEEK_DAY       2
 117#define RTC_FEATURE_CNT                 3
 118
 119#define RTC_MAX_FREQ    8192
 120
 121
 122#endif /* _UAPI_LINUX_RTC_H_ */
 123