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 * read() - Read multiple 8-bit registers
60 *
61 * @dev: Device to read from
62 * @reg: First register to read
63 * @buf: Output buffer
64 * @len: Number of registers to read
65 * @return 0 if OK, -ve on error
66 */
67 int (*read)(struct udevice *dev, unsigned int reg,
68 u8 *buf, unsigned int len);
69
70 /**
71 * write() - Write multiple 8-bit registers
72 *
73 * @dev: Device to write to
74 * @reg: First register to write
75 * @buf: Input buffer
76 * @len: Number of registers to write
77 * @return 0 if OK, -ve on error
78 */
79 int (*write)(struct udevice *dev, unsigned int reg,
80 const u8 *buf, unsigned int len);
81
82 /**
83 * read8() - Read an 8-bit register
84 *
85 * @dev: Device to read from
86 * @reg: Register to read
87 * @return value read, or -ve on error
88 */
89 int (*read8)(struct udevice *dev, unsigned int reg);
90
91 /**
92 * write8() - Write an 8-bit register
93 *
94 * @dev: Device to write to
95 * @reg: Register to write
96 * @value: Value to write
97 * @return 0 if OK, -ve on error
98 */
99 int (*write8)(struct udevice *dev, unsigned int reg, int val);
100 };
101
102 /* Access the operations for an RTC device */
103 #define rtc_get_ops(dev) ((struct rtc_ops *)(dev)->driver->ops)
104
105 /**
106 * dm_rtc_get() - Read the time from an RTC
107 *
108 * @dev: Device to read from
109 * @time: Place to put the current time
110 * @return 0 if OK, -ve on error
111 */
112 int dm_rtc_get(struct udevice *dev, struct rtc_time *time);
113
114 /**
115 * dm_rtc_set() - Write a time to an RTC
116 *
117 * @dev: Device to read from
118 * @time: Time to write into the RTC
119 * @return 0 if OK, -ve on error
120 */
121 int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
122
123 /**
124 * dm_rtc_reset() - reset the RTC to a known-good state
125 *
126 * If the RTC appears to be broken (e.g. it is not counting up in seconds)
127 * it may need to be reset to a known good state. This function achieves this.
128 * After resetting the RTC the time should then be set to a known value by
129 * the caller.
130 *
131 * @dev: Device to read from
132 * @return 0 if OK, -ve on error
133 */
134 int dm_rtc_reset(struct udevice *dev);
135
136 /**
137 * dm_rtc_read() - Read multiple 8-bit registers
138 *
139 * @dev: Device to read from
140 * @reg: First register to read
141 * @buf: Output buffer
142 * @len: Number of registers to read
143 * @return 0 if OK, -ve on error
144 */
145 int dm_rtc_read(struct udevice *dev, unsigned int reg, u8 *buf, unsigned int len);
146
147 /**
148 * dm_rtc_write() - Write multiple 8-bit registers
149 *
150 * @dev: Device to write to
151 * @reg: First register to write
152 * @buf: Input buffer
153 * @len: Number of registers to write
154 * @return 0 if OK, -ve on error
155 */
156 int dm_rtc_write(struct udevice *dev, unsigned int reg,
157 const u8 *buf, unsigned int len);
158
159 /**
160 * rtc_read8() - Read an 8-bit register
161 *
162 * @dev: Device to read from
163 * @reg: Register to read
164 * @return value read, or -ve on error
165 */
166 int rtc_read8(struct udevice *dev, unsigned int reg);
167
168 /**
169 * rtc_write8() - Write an 8-bit register
170 *
171 * @dev: Device to write to
172 * @reg: Register to write
173 * @value: Value to write
174 * @return 0 if OK, -ve on error
175 */
176 int rtc_write8(struct udevice *dev, unsigned int reg, int val);
177
178 /**
179 * rtc_read16() - Read a 16-bit value from the RTC
180 *
181 * @dev: Device to read from
182 * @reg: Offset to start reading from
183 * @valuep: Place to put the value that is read
184 * @return 0 if OK, -ve on error
185 */
186 int rtc_read16(struct udevice *dev, unsigned int reg, u16 *valuep);
187
188 /**
189 * rtc_write16() - Write a 16-bit value to the RTC
190 *
191 * @dev: Device to write to
192 * @reg: Register to start writing to
193 * @value: Value to write
194 * @return 0 if OK, -ve on error
195 */
196 int rtc_write16(struct udevice *dev, unsigned int reg, u16 value);
197
198 /**
199 * rtc_read32() - Read a 32-bit value from the RTC
200 *
201 * @dev: Device to read from
202 * @reg: Offset to start reading from
203 * @valuep: Place to put the value that is read
204 * @return 0 if OK, -ve on error
205 */
206 int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
207
208 /**
209 * rtc_write32() - Write a 32-bit value to the RTC
210 *
211 * @dev: Device to write to
212 * @reg: Register to start writing to
213 * @value: Value to write
214 * @return 0 if OK, -ve on error
215 */
216 int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
217
218 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
219 int rtc_enable_32khz_output(int busnum, int chip_addr);
220 #endif
221
222 #else
223 int rtc_get (struct rtc_time *);
224 int rtc_set (struct rtc_time *);
225 void rtc_reset (void);
226 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
227 void rtc_enable_32khz_output(void);
228 #endif
229
230 /**
231 * rtc_read8() - Read an 8-bit register
232 *
233 * @reg: Register to read
234 * @return value read
235 */
236 int rtc_read8(int reg);
237
238 /**
239 * rtc_write8() - Write an 8-bit register
240 *
241 * @reg: Register to write
242 * @value: Value to write
243 */
244 void rtc_write8(int reg, uchar val);
245
246 /**
247 * rtc_read32() - Read a 32-bit value from the RTC
248 *
249 * @reg: Offset to start reading from
250 * @return value read
251 */
252 u32 rtc_read32(int reg);
253
254 /**
255 * rtc_write32() - Write a 32-bit value to the RTC
256 *
257 * @reg: Register to start writing to
258 * @value: Value to write
259 */
260 void rtc_write32(int reg, u32 value);
261
262 /**
263 * rtc_init() - Set up the real time clock ready for use
264 */
265 void rtc_init(void);
266 #endif /* CONFIG_DM_RTC */
267
268 /**
269 * is_leap_year - Check if year is a leap year
270 *
271 * @year Year
272 * @return 1 if leap year
273 */
is_leap_year(unsigned int year)274 static inline bool is_leap_year(unsigned int year)
275 {
276 return (!(year % 4) && (year % 100)) || !(year % 400);
277 }
278
279 /**
280 * rtc_calc_weekday() - Work out the weekday from a time
281 *
282 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK).
283 * It sets time->tm_wdaay to the correct day of the week.
284 *
285 * @time: Time to inspect. tm_wday is updated
286 * @return 0 if OK, -EINVAL if the weekday could not be determined
287 */
288 int rtc_calc_weekday(struct rtc_time *time);
289
290 /**
291 * rtc_to_tm() - Convert a time_t value into a broken-out time
292 *
293 * The following fields are set up by this function:
294 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
295 *
296 * Note that tm_yday and tm_isdst are set to 0.
297 *
298 * @time_t: Number of seconds since 1970-01-01 00:00:00
299 * @time: Place to put the broken-out time
300 */
301 void rtc_to_tm(u64 time_t, struct rtc_time *time);
302
303 /**
304 * rtc_mktime() - Convert a broken-out time into a time_t value
305 *
306 * The following fields need to be valid for this function to work:
307 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year
308 *
309 * Note that tm_wday and tm_yday are ignored.
310 *
311 * @time: Broken-out time to convert
312 * @return corresponding time_t value, seconds since 1970-01-01 00:00:00
313 */
314 unsigned long rtc_mktime(const struct rtc_time *time);
315
316 /**
317 * rtc_month_days() - The number of days in the month
318 *
319 * @month: month (January = 0)
320 * @year: year (4 digits)
321 */
322 int rtc_month_days(unsigned int month, unsigned int year);
323
324 #endif /* _RTC_H_ */
325