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 _LINUX_RTC_H_
13#define _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 /* _LINUX_RTC_H_ */
123

source code of include/linux/rtc.h