xref: /linux/include/uapi/linux/rtc.h (revision 44f57d78)
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 /*
16  * The struct used to pass data via the following ioctl. Similar to the
17  * struct tm in <time.h>, but it needs to be here so that the kernel
18  * source is self contained, allowing cross-compiles, etc. etc.
19  */
20 
21 struct rtc_time {
22 	int tm_sec;
23 	int tm_min;
24 	int tm_hour;
25 	int tm_mday;
26 	int tm_mon;
27 	int tm_year;
28 	int tm_wday;
29 	int tm_yday;
30 	int tm_isdst;
31 };
32 
33 /*
34  * This data structure is inspired by the EFI (v0.92) wakeup
35  * alarm API.
36  */
37 struct rtc_wkalrm {
38 	unsigned char enabled;	/* 0 = alarm disabled, 1 = alarm enabled */
39 	unsigned char pending;  /* 0 = alarm not pending, 1 = alarm pending */
40 	struct rtc_time time;	/* time the alarm is set to */
41 };
42 
43 /*
44  * Data structure to control PLL correction some better RTC feature
45  * pll_value is used to get or set current value of correction,
46  * the rest of the struct is used to query HW capabilities.
47  * This is modeled after the RTC used in Q40/Q60 computers but
48  * should be sufficiently flexible for other devices
49  *
50  * +ve pll_value means clock will run faster by
51  *   pll_value*pll_posmult/pll_clock
52  * -ve pll_value means clock will run slower by
53  *   pll_value*pll_negmult/pll_clock
54  */
55 
56 struct rtc_pll_info {
57 	int pll_ctrl;       /* placeholder for fancier control */
58 	int pll_value;      /* get/set correction value */
59 	int pll_max;        /* max +ve (faster) adjustment value */
60 	int pll_min;        /* max -ve (slower) adjustment value */
61 	int pll_posmult;    /* factor for +ve correction */
62 	int pll_negmult;    /* factor for -ve correction */
63 	long pll_clock;     /* base PLL frequency */
64 };
65 
66 /*
67  * ioctl calls that are permitted to the /dev/rtc interface, if
68  * any of the RTC drivers are enabled.
69  */
70 
71 #define RTC_AIE_ON	_IO('p', 0x01)	/* Alarm int. enable on		*/
72 #define RTC_AIE_OFF	_IO('p', 0x02)	/* ... off			*/
73 #define RTC_UIE_ON	_IO('p', 0x03)	/* Update int. enable on	*/
74 #define RTC_UIE_OFF	_IO('p', 0x04)	/* ... off			*/
75 #define RTC_PIE_ON	_IO('p', 0x05)	/* Periodic int. enable on	*/
76 #define RTC_PIE_OFF	_IO('p', 0x06)	/* ... off			*/
77 #define RTC_WIE_ON	_IO('p', 0x0f)  /* Watchdog int. enable on	*/
78 #define RTC_WIE_OFF	_IO('p', 0x10)  /* ... off			*/
79 
80 #define RTC_ALM_SET	_IOW('p', 0x07, struct rtc_time) /* Set alarm time  */
81 #define RTC_ALM_READ	_IOR('p', 0x08, struct rtc_time) /* Read alarm time */
82 #define RTC_RD_TIME	_IOR('p', 0x09, struct rtc_time) /* Read RTC time   */
83 #define RTC_SET_TIME	_IOW('p', 0x0a, struct rtc_time) /* Set RTC time    */
84 #define RTC_IRQP_READ	_IOR('p', 0x0b, unsigned long)	 /* Read IRQ rate   */
85 #define RTC_IRQP_SET	_IOW('p', 0x0c, unsigned long)	 /* Set IRQ rate    */
86 #define RTC_EPOCH_READ	_IOR('p', 0x0d, unsigned long)	 /* Read epoch      */
87 #define RTC_EPOCH_SET	_IOW('p', 0x0e, unsigned long)	 /* Set epoch       */
88 
89 #define RTC_WKALM_SET	_IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
90 #define RTC_WKALM_RD	_IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
91 
92 #define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
93 #define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
94 
95 #define RTC_VL_READ	_IOR('p', 0x13, int)	/* Voltage low detector */
96 #define RTC_VL_CLR	_IO('p', 0x14)		/* Clear voltage low information */
97 
98 /* interrupt flags */
99 #define RTC_IRQF 0x80	/* Any of the following is active */
100 #define RTC_PF 0x40	/* Periodic interrupt */
101 #define RTC_AF 0x20	/* Alarm interrupt */
102 #define RTC_UF 0x10	/* Update interrupt for 1Hz RTC */
103 
104 
105 #define RTC_MAX_FREQ	8192
106 
107 
108 #endif /* _UAPI_LINUX_RTC_H_ */
109