xref: /openbmc/u-boot/include/rtc.h (revision 8df37888)
1 /*
2  * (C) Copyright 2001
3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 /*
9  * Generic RTC interface.
10  */
11 #ifndef _RTC_H_
12 #define _RTC_H_
13 
14 /* bcd<->bin functions are needed by almost all the RTC drivers, let's include
15  * it there instead of in evey single driver */
16 
17 #include <bcd.h>
18 #include <rtc_def.h>
19 
20 #ifdef CONFIG_DM_RTC
21 
22 struct rtc_ops {
23 	/**
24 	 * get() - get the current time
25 	 *
26 	 * Returns the current time read from the RTC device. The driver
27 	 * is responsible for setting up every field in the structure.
28 	 *
29 	 * @dev:	Device to read from
30 	 * @time:	Place to put the time that is read
31 	 */
32 	int (*get)(struct udevice *dev, struct rtc_time *time);
33 
34 	/**
35 	 * set() - set the current time
36 	 *
37 	 * Sets the time in the RTC device. The driver can expect every
38 	 * field to be set correctly.
39 	 *
40 	 * @dev:	Device to read from
41 	 * @time:	Time to write
42 	 */
43 	int (*set)(struct udevice *dev, const struct rtc_time *time);
44 
45 	/**
46 	 * reset() - reset the RTC to a known-good state
47 	 *
48 	 * This function resets the RTC to a known-good state. The time may
49 	 * be unset by this method, so should be set after this method is
50 	 * called.
51 	 *
52 	 * @dev:	Device to read from
53 	 * @return 0 if OK, -ve on error
54 	 */
55 	int (*reset)(struct udevice *dev);
56 
57 	/**
58 	 * read8() - Read an 8-bit register
59 	 *
60 	 * @dev:	Device to read from
61 	 * @reg:	Register to read
62 	 * @return value read, or -ve on error
63 	 */
64 	int (*read8)(struct udevice *dev, unsigned int reg);
65 
66 	/**
67 	* write8() - Write an 8-bit register
68 	*
69 	* @dev:		Device to write to
70 	* @reg:		Register to write
71 	* @value:	Value to write
72 	* @return 0 if OK, -ve on error
73 	*/
74 	int (*write8)(struct udevice *dev, unsigned int reg, int val);
75 };
76 
77 /* Access the operations for an RTC device */
78 #define rtc_get_ops(dev)	((struct rtc_ops *)(dev)->driver->ops)
79 
80 /**
81  * dm_rtc_get() - Read the time from an RTC
82  *
83  * @dev:	Device to read from
84  * @time:	Place to put the current time
85  * @return 0 if OK, -ve on error
86  */
87 int dm_rtc_get(struct udevice *dev, struct rtc_time *time);
88 
89 /**
90  * dm_rtc_put() - Write a time to an RTC
91  *
92  * @dev:	Device to read from
93  * @time:	Time to write into the RTC
94  * @return 0 if OK, -ve on error
95  */
96 int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
97 
98 /**
99  * dm_rtc_reset() - reset the RTC to a known-good state
100  *
101  * If the RTC appears to be broken (e.g. it is not counting up in seconds)
102  * it may need to be reset to a known good state. This function achieves this.
103  * After resetting the RTC the time should then be set to a known value by
104  * the caller.
105  *
106  * @dev:	Device to read from
107  * @return 0 if OK, -ve on error
108  */
109 int dm_rtc_reset(struct udevice *dev);
110 
111 /**
112  * rtc_read8() - Read an 8-bit register
113  *
114  * @dev:	Device to read from
115  * @reg:	Register to read
116  * @return value read, or -ve on error
117  */
118 int rtc_read8(struct udevice *dev, unsigned int reg);
119 
120 /**
121  * rtc_write8() - Write an 8-bit register
122  *
123  * @dev:	Device to write to
124  * @reg:	Register to write
125  * @value:	Value to write
126  * @return 0 if OK, -ve on error
127  */
128 int rtc_write8(struct udevice *dev, unsigned int reg, int val);
129 
130 /**
131  * rtc_read16() - Read a 16-bit value from the RTC
132  *
133  * @dev:	Device to read from
134  * @reg:	Offset to start reading from
135  * @valuep:	Place to put the value that is read
136  * @return 0 if OK, -ve on error
137  */
138 int rtc_read16(struct udevice *dev, unsigned int reg, u16 *valuep);
139 
140 /**
141  * rtc_write16() - Write a 16-bit value to the RTC
142  *
143  * @dev:	Device to write to
144  * @reg:	Register to start writing to
145  * @value:	Value to write
146  * @return 0 if OK, -ve on error
147  */
148 int rtc_write16(struct udevice *dev, unsigned int reg, u16 value);
149 
150 /**
151  * rtc_read32() - Read a 32-bit value from the RTC
152  *
153  * @dev:	Device to read from
154  * @reg:	Offset to start reading from
155  * @valuep:	Place to put the value that is read
156  * @return 0 if OK, -ve on error
157  */
158 int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
159 
160 /**
161  * rtc_write32() - Write a 32-bit value to the RTC
162  *
163  * @dev:	Device to write to
164  * @reg:	Register to start writing to
165  * @value:	Value to write
166  * @return 0 if OK, -ve on error
167  */
168 int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
169 
170 #else
171 int rtc_get (struct rtc_time *);
172 int rtc_set (struct rtc_time *);
173 void rtc_reset (void);
174 void rtc_enable_32khz_output(void);
175 
176 /**
177  * rtc_read8() - Read an 8-bit register
178  *
179  * @reg:	Register to read
180  * @return value read
181  */
182 int rtc_read8(int reg);
183 
184 /**
185  * rtc_write8() - Write an 8-bit register
186  *
187  * @reg:	Register to write
188  * @value:	Value to write
189  */
190 void rtc_write8(int reg, uchar val);
191 
192 /**
193  * rtc_read32() - Read a 32-bit value from the RTC
194  *
195  * @reg:	Offset to start reading from
196  * @return value read
197  */
198 u32 rtc_read32(int reg);
199 
200 /**
201  * rtc_write32() - Write a 32-bit value to the RTC
202  *
203  * @reg:	Register to start writing to
204  * @value:	Value to write
205  */
206 void rtc_write32(int reg, u32 value);
207 
208 /**
209  * rtc_init() - Set up the real time clock ready for use
210  */
211 void rtc_init(void);
212 #endif
213 
214 /**
215  * rtc_calc_weekday() - Work out the weekday from a time
216  *
217  * This only works for the Gregorian calendar - i.e. after 1752 (in the UK).
218  * It sets time->tm_wdaay to the correct day of the week.
219  *
220  * @time:	Time to inspect. tm_wday is updated
221  * @return 0 if OK, -EINVAL if the weekday could not be determined
222  */
223 int rtc_calc_weekday(struct rtc_time *time);
224 
225 /**
226  * rtc_to_tm() - Convert a time_t value into a broken-out time
227  *
228  * The following fields are set up by this function:
229  *	tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
230  *
231  * Note that tm_yday and tm_isdst are set to 0.
232  *
233  * @time_t:	Number of seconds since 1970-01-01 00:00:00
234  * @time:	Place to put the broken-out time
235  * @return 0 if OK, -EINVAL if the weekday could not be determined
236  */
237 int rtc_to_tm(int time_t, struct rtc_time *time);
238 
239 /**
240  * rtc_mktime() - Convert a broken-out time into a time_t value
241  *
242  * The following fields need to be valid for this function to work:
243  *	tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year
244  *
245  * Note that tm_wday and tm_yday are ignored.
246  *
247  * @time:	Broken-out time to convert
248  * @return corresponding time_t value, seconds since 1970-01-01 00:00:00
249  */
250 unsigned long rtc_mktime(const struct rtc_time *time);
251 
252 #endif	/* _RTC_H_ */
253