xref: /openbmc/linux/include/linux/rtc.h (revision 95e9fd10)
1 /*
2  * Generic RTC interface.
3  * This version contains the part of the user interface to the Real Time Clock
4  * service. It is used with both the legacy mc146818 and also  EFI
5  * Struct rtc_time and first 12 ioctl by Paul Gortmaker, 1996 - separated out
6  * from <linux/mc146818rtc.h> to this file for 2.4 kernels.
7  *
8  * Copyright (C) 1999 Hewlett-Packard Co.
9  * Copyright (C) 1999 Stephane Eranian <eranian@hpl.hp.com>
10  */
11 #ifndef _LINUX_RTC_H_
12 #define _LINUX_RTC_H_
13 
14 /*
15  * The struct used to pass data via the following ioctl. Similar to the
16  * struct tm in <time.h>, but it needs to be here so that the kernel
17  * source is self contained, allowing cross-compiles, etc. etc.
18  */
19 
20 struct rtc_time {
21 	int tm_sec;
22 	int tm_min;
23 	int tm_hour;
24 	int tm_mday;
25 	int tm_mon;
26 	int tm_year;
27 	int tm_wday;
28 	int tm_yday;
29 	int tm_isdst;
30 };
31 
32 /*
33  * This data structure is inspired by the EFI (v0.92) wakeup
34  * alarm API.
35  */
36 struct rtc_wkalrm {
37 	unsigned char enabled;	/* 0 = alarm disabled, 1 = alarm enabled */
38 	unsigned char pending;  /* 0 = alarm not pending, 1 = alarm pending */
39 	struct rtc_time time;	/* time the alarm is set to */
40 };
41 
42 /*
43  * Data structure to control PLL correction some better RTC feature
44  * pll_value is used to get or set current value of correction,
45  * the rest of the struct is used to query HW capabilities.
46  * This is modeled after the RTC used in Q40/Q60 computers but
47  * should be sufficiently flexible for other devices
48  *
49  * +ve pll_value means clock will run faster by
50  *   pll_value*pll_posmult/pll_clock
51  * -ve pll_value means clock will run slower by
52  *   pll_value*pll_negmult/pll_clock
53  */
54 
55 struct rtc_pll_info {
56 	int pll_ctrl;       /* placeholder for fancier control */
57 	int pll_value;      /* get/set correction value */
58 	int pll_max;        /* max +ve (faster) adjustment value */
59 	int pll_min;        /* max -ve (slower) adjustment value */
60 	int pll_posmult;    /* factor for +ve correction */
61 	int pll_negmult;    /* factor for -ve correction */
62 	long pll_clock;     /* base PLL frequency */
63 };
64 
65 /*
66  * ioctl calls that are permitted to the /dev/rtc interface, if
67  * any of the RTC drivers are enabled.
68  */
69 
70 #define RTC_AIE_ON	_IO('p', 0x01)	/* Alarm int. enable on		*/
71 #define RTC_AIE_OFF	_IO('p', 0x02)	/* ... off			*/
72 #define RTC_UIE_ON	_IO('p', 0x03)	/* Update int. enable on	*/
73 #define RTC_UIE_OFF	_IO('p', 0x04)	/* ... off			*/
74 #define RTC_PIE_ON	_IO('p', 0x05)	/* Periodic int. enable on	*/
75 #define RTC_PIE_OFF	_IO('p', 0x06)	/* ... off			*/
76 #define RTC_WIE_ON	_IO('p', 0x0f)  /* Watchdog int. enable on	*/
77 #define RTC_WIE_OFF	_IO('p', 0x10)  /* ... off			*/
78 
79 #define RTC_ALM_SET	_IOW('p', 0x07, struct rtc_time) /* Set alarm time  */
80 #define RTC_ALM_READ	_IOR('p', 0x08, struct rtc_time) /* Read alarm time */
81 #define RTC_RD_TIME	_IOR('p', 0x09, struct rtc_time) /* Read RTC time   */
82 #define RTC_SET_TIME	_IOW('p', 0x0a, struct rtc_time) /* Set RTC time    */
83 #define RTC_IRQP_READ	_IOR('p', 0x0b, unsigned long)	 /* Read IRQ rate   */
84 #define RTC_IRQP_SET	_IOW('p', 0x0c, unsigned long)	 /* Set IRQ rate    */
85 #define RTC_EPOCH_READ	_IOR('p', 0x0d, unsigned long)	 /* Read epoch      */
86 #define RTC_EPOCH_SET	_IOW('p', 0x0e, unsigned long)	 /* Set epoch       */
87 
88 #define RTC_WKALM_SET	_IOW('p', 0x0f, struct rtc_wkalrm)/* Set wakeup alarm*/
89 #define RTC_WKALM_RD	_IOR('p', 0x10, struct rtc_wkalrm)/* Get wakeup alarm*/
90 
91 #define RTC_PLL_GET	_IOR('p', 0x11, struct rtc_pll_info)  /* Get PLL correction */
92 #define RTC_PLL_SET	_IOW('p', 0x12, struct rtc_pll_info)  /* Set PLL correction */
93 
94 #define RTC_VL_READ	_IOR('p', 0x13, int)	/* Voltage low detector */
95 #define RTC_VL_CLR	_IO('p', 0x14)		/* Clear voltage low information */
96 
97 /* interrupt flags */
98 #define RTC_IRQF 0x80	/* Any of the following is active */
99 #define RTC_PF 0x40	/* Periodic interrupt */
100 #define RTC_AF 0x20	/* Alarm interrupt */
101 #define RTC_UF 0x10	/* Update interrupt for 1Hz RTC */
102 
103 
104 #define RTC_MAX_FREQ	8192
105 
106 #ifdef __KERNEL__
107 
108 #include <linux/types.h>
109 #include <linux/interrupt.h>
110 
111 extern int rtc_month_days(unsigned int month, unsigned int year);
112 extern int rtc_year_days(unsigned int day, unsigned int month, unsigned int year);
113 extern int rtc_valid_tm(struct rtc_time *tm);
114 extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
115 extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
116 ktime_t rtc_tm_to_ktime(struct rtc_time tm);
117 struct rtc_time rtc_ktime_to_tm(ktime_t kt);
118 
119 
120 #include <linux/device.h>
121 #include <linux/seq_file.h>
122 #include <linux/cdev.h>
123 #include <linux/poll.h>
124 #include <linux/mutex.h>
125 #include <linux/timerqueue.h>
126 #include <linux/workqueue.h>
127 
128 extern struct class *rtc_class;
129 
130 /*
131  * For these RTC methods the device parameter is the physical device
132  * on whatever bus holds the hardware (I2C, Platform, SPI, etc), which
133  * was passed to rtc_device_register().  Its driver_data normally holds
134  * device state, including the rtc_device pointer for the RTC.
135  *
136  * Most of these methods are called with rtc_device.ops_lock held,
137  * through the rtc_*(struct rtc_device *, ...) calls.
138  *
139  * The (current) exceptions are mostly filesystem hooks:
140  *   - the proc() hook for procfs
141  *   - non-ioctl() chardev hooks:  open(), release(), read_callback()
142  *
143  * REVISIT those periodic irq calls *do* have ops_lock when they're
144  * issued through ioctl() ...
145  */
146 struct rtc_class_ops {
147 	int (*open)(struct device *);
148 	void (*release)(struct device *);
149 	int (*ioctl)(struct device *, unsigned int, unsigned long);
150 	int (*read_time)(struct device *, struct rtc_time *);
151 	int (*set_time)(struct device *, struct rtc_time *);
152 	int (*read_alarm)(struct device *, struct rtc_wkalrm *);
153 	int (*set_alarm)(struct device *, struct rtc_wkalrm *);
154 	int (*proc)(struct device *, struct seq_file *);
155 	int (*set_mmss)(struct device *, unsigned long secs);
156 	int (*read_callback)(struct device *, int data);
157 	int (*alarm_irq_enable)(struct device *, unsigned int enabled);
158 };
159 
160 #define RTC_DEVICE_NAME_SIZE 20
161 typedef struct rtc_task {
162 	void (*func)(void *private_data);
163 	void *private_data;
164 } rtc_task_t;
165 
166 
167 struct rtc_timer {
168 	struct rtc_task	task;
169 	struct timerqueue_node node;
170 	ktime_t period;
171 	int enabled;
172 };
173 
174 
175 /* flags */
176 #define RTC_DEV_BUSY 0
177 
178 struct rtc_device
179 {
180 	struct device dev;
181 	struct module *owner;
182 
183 	int id;
184 	char name[RTC_DEVICE_NAME_SIZE];
185 
186 	const struct rtc_class_ops *ops;
187 	struct mutex ops_lock;
188 
189 	struct cdev char_dev;
190 	unsigned long flags;
191 
192 	unsigned long irq_data;
193 	spinlock_t irq_lock;
194 	wait_queue_head_t irq_queue;
195 	struct fasync_struct *async_queue;
196 
197 	struct rtc_task *irq_task;
198 	spinlock_t irq_task_lock;
199 	int irq_freq;
200 	int max_user_freq;
201 
202 	struct timerqueue_head timerqueue;
203 	struct rtc_timer aie_timer;
204 	struct rtc_timer uie_rtctimer;
205 	struct hrtimer pie_timer; /* sub second exp, so needs hrtimer */
206 	int pie_enabled;
207 	struct work_struct irqwork;
208 	/* Some hardware can't support UIE mode */
209 	int uie_unsupported;
210 
211 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
212 	struct work_struct uie_task;
213 	struct timer_list uie_timer;
214 	/* Those fields are protected by rtc->irq_lock */
215 	unsigned int oldsecs;
216 	unsigned int uie_irq_active:1;
217 	unsigned int stop_uie_polling:1;
218 	unsigned int uie_task_active:1;
219 	unsigned int uie_timer_active:1;
220 #endif
221 };
222 #define to_rtc_device(d) container_of(d, struct rtc_device, dev)
223 
224 extern struct rtc_device *rtc_device_register(const char *name,
225 					struct device *dev,
226 					const struct rtc_class_ops *ops,
227 					struct module *owner);
228 extern void rtc_device_unregister(struct rtc_device *rtc);
229 
230 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
231 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
232 extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
233 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
234 extern int rtc_read_alarm(struct rtc_device *rtc,
235 			struct rtc_wkalrm *alrm);
236 extern int rtc_set_alarm(struct rtc_device *rtc,
237 				struct rtc_wkalrm *alrm);
238 extern int rtc_initialize_alarm(struct rtc_device *rtc,
239 				struct rtc_wkalrm *alrm);
240 extern void rtc_update_irq(struct rtc_device *rtc,
241 			unsigned long num, unsigned long events);
242 
243 extern struct rtc_device *rtc_class_open(char *name);
244 extern void rtc_class_close(struct rtc_device *rtc);
245 
246 extern int rtc_irq_register(struct rtc_device *rtc,
247 				struct rtc_task *task);
248 extern void rtc_irq_unregister(struct rtc_device *rtc,
249 				struct rtc_task *task);
250 extern int rtc_irq_set_state(struct rtc_device *rtc,
251 				struct rtc_task *task, int enabled);
252 extern int rtc_irq_set_freq(struct rtc_device *rtc,
253 				struct rtc_task *task, int freq);
254 extern int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled);
255 extern int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled);
256 extern int rtc_dev_update_irq_enable_emul(struct rtc_device *rtc,
257 						unsigned int enabled);
258 
259 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode);
260 void rtc_aie_update_irq(void *private);
261 void rtc_uie_update_irq(void *private);
262 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer);
263 
264 int rtc_register(rtc_task_t *task);
265 int rtc_unregister(rtc_task_t *task);
266 int rtc_control(rtc_task_t *t, unsigned int cmd, unsigned long arg);
267 
268 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data);
269 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer,
270 			ktime_t expires, ktime_t period);
271 int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer);
272 void rtc_timer_do_work(struct work_struct *work);
273 
274 static inline bool is_leap_year(unsigned int year)
275 {
276 	return (!(year % 4) && (year % 100)) || !(year % 400);
277 }
278 
279 #ifdef CONFIG_RTC_HCTOSYS
280 extern int rtc_hctosys_ret;
281 #else
282 #define rtc_hctosys_ret -ENODEV
283 #endif
284 
285 #endif /* __KERNEL__ */
286 
287 #endif /* _LINUX_RTC_H_ */
288