1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * (C) Copyright 2001
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 */
6
7 /*
8 * Generic RTC interface.
9 */
10 #ifndef _RTC_H_
11 #define _RTC_H_
12
13 /* bcd<->bin functions are needed by almost all the RTC drivers, let's include
14 * it there instead of in evey single driver */
15
16 #include <bcd.h>
17 #include <rtc_def.h>
18
19 #ifdef CONFIG_DM_RTC
20
21 struct udevice;
22
23 struct rtc_ops {
24 /**
25 * get() - get the current time
26 *
27 * Returns the current time read from the RTC device. The driver
28 * is responsible for setting up every field in the structure.
29 *
30 * @dev: Device to read from
31 * @time: Place to put the time that is read
32 */
33 int (*get)(struct udevice *dev, struct rtc_time *time);
34
35 /**
36 * set() - set the current time
37 *
38 * Sets the time in the RTC device. The driver can expect every
39 * field to be set correctly.
40 *
41 * @dev: Device to read from
42 * @time: Time to write
43 */
44 int (*set)(struct udevice *dev, const struct rtc_time *time);
45
46 /**
47 * reset() - reset the RTC to a known-good state
48 *
49 * This function resets the RTC to a known-good state. The time may
50 * be unset by this method, so should be set after this method is
51 * called.
52 *
53 * @dev: Device to read from
54 * @return 0 if OK, -ve on error
55 */
56 int (*reset)(struct udevice *dev);
57
58 /**
59 * read8() - Read an 8-bit register
60 *
61 * @dev: Device to read from
62 * @reg: Register to read
63 * @return value read, or -ve on error
64 */
65 int (*read8)(struct udevice *dev, unsigned int reg);
66
67 /**
68 * write8() - Write an 8-bit register
69 *
70 * @dev: Device to write to
71 * @reg: Register to write
72 * @value: Value to write
73 * @return 0 if OK, -ve on error
74 */
75 int (*write8)(struct udevice *dev, unsigned int reg, int val);
76 };
77
78 /* Access the operations for an RTC device */
79 #define rtc_get_ops(dev) ((struct rtc_ops *)(dev)->driver->ops)
80
81 /**
82 * dm_rtc_get() - Read the time from an RTC
83 *
84 * @dev: Device to read from
85 * @time: Place to put the current time
86 * @return 0 if OK, -ve on error
87 */
88 int dm_rtc_get(struct udevice *dev, struct rtc_time *time);
89
90 /**
91 * dm_rtc_set() - Write a time to an RTC
92 *
93 * @dev: Device to read from
94 * @time: Time to write into the RTC
95 * @return 0 if OK, -ve on error
96 */
97 int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
98
99 /**
100 * dm_rtc_reset() - reset the RTC to a known-good state
101 *
102 * If the RTC appears to be broken (e.g. it is not counting up in seconds)
103 * it may need to be reset to a known good state. This function achieves this.
104 * After resetting the RTC the time should then be set to a known value by
105 * the caller.
106 *
107 * @dev: Device to read from
108 * @return 0 if OK, -ve on error
109 */
110 int dm_rtc_reset(struct udevice *dev);
111
112 /**
113 * rtc_read8() - Read an 8-bit register
114 *
115 * @dev: Device to read from
116 * @reg: Register to read
117 * @return value read, or -ve on error
118 */
119 int rtc_read8(struct udevice *dev, unsigned int reg);
120
121 /**
122 * rtc_write8() - Write an 8-bit register
123 *
124 * @dev: Device to write to
125 * @reg: Register to write
126 * @value: Value to write
127 * @return 0 if OK, -ve on error
128 */
129 int rtc_write8(struct udevice *dev, unsigned int reg, int val);
130
131 /**
132 * rtc_read16() - Read a 16-bit value from the RTC
133 *
134 * @dev: Device to read from
135 * @reg: Offset to start reading from
136 * @valuep: Place to put the value that is read
137 * @return 0 if OK, -ve on error
138 */
139 int rtc_read16(struct udevice *dev, unsigned int reg, u16 *valuep);
140
141 /**
142 * rtc_write16() - Write a 16-bit value to the RTC
143 *
144 * @dev: Device to write to
145 * @reg: Register to start writing to
146 * @value: Value to write
147 * @return 0 if OK, -ve on error
148 */
149 int rtc_write16(struct udevice *dev, unsigned int reg, u16 value);
150
151 /**
152 * rtc_read32() - Read a 32-bit value from the RTC
153 *
154 * @dev: Device to read from
155 * @reg: Offset to start reading from
156 * @valuep: Place to put the value that is read
157 * @return 0 if OK, -ve on error
158 */
159 int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
160
161 /**
162 * rtc_write32() - Write a 32-bit value to the RTC
163 *
164 * @dev: Device to write to
165 * @reg: Register to start writing to
166 * @value: Value to write
167 * @return 0 if OK, -ve on error
168 */
169 int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
170
171 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
172 int rtc_enable_32khz_output(int busnum, int chip_addr);
173 #endif
174
175 #else
176 int rtc_get (struct rtc_time *);
177 int rtc_set (struct rtc_time *);
178 void rtc_reset (void);
179 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
180 void rtc_enable_32khz_output(void);
181 #endif
182
183 /**
184 * rtc_read8() - Read an 8-bit register
185 *
186 * @reg: Register to read
187 * @return value read
188 */
189 int rtc_read8(int reg);
190
191 /**
192 * rtc_write8() - Write an 8-bit register
193 *
194 * @reg: Register to write
195 * @value: Value to write
196 */
197 void rtc_write8(int reg, uchar val);
198
199 /**
200 * rtc_read32() - Read a 32-bit value from the RTC
201 *
202 * @reg: Offset to start reading from
203 * @return value read
204 */
205 u32 rtc_read32(int reg);
206
207 /**
208 * rtc_write32() - Write a 32-bit value to the RTC
209 *
210 * @reg: Register to start writing to
211 * @value: Value to write
212 */
213 void rtc_write32(int reg, u32 value);
214
215 /**
216 * rtc_init() - Set up the real time clock ready for use
217 */
218 void rtc_init(void);
219 #endif /* CONFIG_DM_RTC */
220
221 /**
222 * is_leap_year - Check if year is a leap year
223 *
224 * @year Year
225 * @return 1 if leap year
226 */
is_leap_year(unsigned int year)227 static inline bool is_leap_year(unsigned int year)
228 {
229 return (!(year % 4) && (year % 100)) || !(year % 400);
230 }
231
232 /**
233 * rtc_calc_weekday() - Work out the weekday from a time
234 *
235 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK).
236 * It sets time->tm_wdaay to the correct day of the week.
237 *
238 * @time: Time to inspect. tm_wday is updated
239 * @return 0 if OK, -EINVAL if the weekday could not be determined
240 */
241 int rtc_calc_weekday(struct rtc_time *time);
242
243 /**
244 * rtc_to_tm() - Convert a time_t value into a broken-out time
245 *
246 * The following fields are set up by this function:
247 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
248 *
249 * Note that tm_yday and tm_isdst are set to 0.
250 *
251 * @time_t: Number of seconds since 1970-01-01 00:00:00
252 * @time: Place to put the broken-out time
253 */
254 void rtc_to_tm(u64 time_t, struct rtc_time *time);
255
256 /**
257 * rtc_mktime() - Convert a broken-out time into a time_t value
258 *
259 * The following fields need to be valid for this function to work:
260 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year
261 *
262 * Note that tm_wday and tm_yday are ignored.
263 *
264 * @time: Broken-out time to convert
265 * @return corresponding time_t value, seconds since 1970-01-01 00:00:00
266 */
267 unsigned long rtc_mktime(const struct rtc_time *time);
268
269 /**
270 * rtc_month_days() - The number of days in the month
271 *
272 * @month: month (January = 0)
273 * @year: year (4 digits)
274 */
275 int rtc_month_days(unsigned int month, unsigned int year);
276
277 #endif /* _RTC_H_ */
278