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 #include <linux/errno.h>
19 #include <linux/types.h>
20
21 typedef int64_t time64_t;
22 struct udevice;
23
24 #if CONFIG_IS_ENABLED(DM_RTC)
25 struct rtc_ops {
26 /**
27 * get() - get the current time
28 *
29 * Returns the current time read from the RTC device. The driver
30 * is responsible for setting up every field in the structure.
31 *
32 * @dev: Device to read from
33 * @time: Place to put the time that is read
34 */
35 int (*get)(struct udevice *dev, struct rtc_time *time);
36
37 /**
38 * set() - set the current time
39 *
40 * Sets the time in the RTC device. The driver can expect every
41 * field to be set correctly.
42 *
43 * @dev: Device to read from
44 * @time: Time to write
45 */
46 int (*set)(struct udevice *dev, const struct rtc_time *time);
47
48 /**
49 * reset() - reset the RTC to a known-good state
50 *
51 * This function resets the RTC to a known-good state. The time may
52 * be unset by this method, so should be set after this method is
53 * called.
54 *
55 * @dev: Device to read from
56 * @return 0 if OK, -ve on error
57 */
58 int (*reset)(struct udevice *dev);
59
60 /**
61 * read() - Read multiple 8-bit registers
62 *
63 * @dev: Device to read from
64 * @reg: First register to read
65 * @buf: Output buffer
66 * @len: Number of registers to read
67 * @return 0 if OK, -ve on error
68 */
69 int (*read)(struct udevice *dev, unsigned int reg,
70 u8 *buf, unsigned int len);
71
72 /**
73 * write() - Write multiple 8-bit registers
74 *
75 * @dev: Device to write to
76 * @reg: First register to write
77 * @buf: Input buffer
78 * @len: Number of registers to write
79 * @return 0 if OK, -ve on error
80 */
81 int (*write)(struct udevice *dev, unsigned int reg,
82 const u8 *buf, unsigned int len);
83
84 /**
85 * read8() - Read an 8-bit register
86 *
87 * @dev: Device to read from
88 * @reg: Register to read
89 * @return value read, or -ve on error
90 */
91 int (*read8)(struct udevice *dev, unsigned int reg);
92
93 /**
94 * write8() - Write an 8-bit register
95 *
96 * @dev: Device to write to
97 * @reg: Register to write
98 * @value: Value to write
99 * Return: 0 if OK, -ve on error
100 */
101 int (*write8)(struct udevice *dev, unsigned int reg, int val);
102 };
103
104 /* Access the operations for an RTC device */
105 #define rtc_get_ops(dev) ((struct rtc_ops *)(dev)->driver->ops)
106
107 /**
108 * dm_rtc_get() - Read the time from an RTC
109 *
110 * @dev: Device to read from
111 * @time: Place to put the current time
112 * Return: 0 if OK, -ve on error
113 */
114 int dm_rtc_get(struct udevice *dev, struct rtc_time *time);
115
116 /**
117 * dm_rtc_set() - Write a time to an RTC
118 *
119 * @dev: Device to read from
120 * @time: Time to write into the RTC
121 * Return: 0 if OK, -ve on error
122 */
123 int dm_rtc_set(struct udevice *dev, struct rtc_time *time);
124
125 /**
126 * dm_rtc_reset() - reset the RTC to a known-good state
127 *
128 * If the RTC appears to be broken (e.g. it is not counting up in seconds)
129 * it may need to be reset to a known good state. This function achieves this.
130 * After resetting the RTC the time should then be set to a known value by
131 * the caller.
132 *
133 * @dev: Device to read from
134 * Return: 0 if OK, -ve on error
135 */
136 int dm_rtc_reset(struct udevice *dev);
137
138 /**
139 * dm_rtc_read() - Read multiple 8-bit registers
140 *
141 * @dev: Device to read from
142 * @reg: First register to read
143 * @buf: Output buffer
144 * @len: Number of registers to read
145 * Return: 0 if OK, -ve on error
146 */
147 int dm_rtc_read(struct udevice *dev, unsigned int reg, u8 *buf, unsigned int len);
148
149 /**
150 * dm_rtc_write() - Write multiple 8-bit registers
151 *
152 * @dev: Device to write to
153 * @reg: First register to write
154 * @buf: Input buffer
155 * @len: Number of registers to write
156 * Return: 0 if OK, -ve on error
157 */
158 int dm_rtc_write(struct udevice *dev, unsigned int reg,
159 const u8 *buf, unsigned int len);
160
161 /**
162 * rtc_read8() - Read an 8-bit register
163 *
164 * @dev: Device to read from
165 * @reg: Register to read
166 * Return: value read, or -ve on error
167 */
168 int rtc_read8(struct udevice *dev, unsigned int reg);
169
170 /**
171 * rtc_write8() - Write an 8-bit register
172 *
173 * @dev: Device to write to
174 * @reg: Register to write
175 * @value: Value to write
176 * Return: 0 if OK, -ve on error
177 */
178 int rtc_write8(struct udevice *dev, unsigned int reg, int val);
179
180 /**
181 * rtc_read16() - Read a 16-bit value from the RTC
182 *
183 * @dev: Device to read from
184 * @reg: Offset to start reading from
185 * @valuep: Place to put the value that is read
186 * Return: 0 if OK, -ve on error
187 */
188 int rtc_read16(struct udevice *dev, unsigned int reg, u16 *valuep);
189
190 /**
191 * rtc_write16() - Write a 16-bit value to the RTC
192 *
193 * @dev: Device to write to
194 * @reg: Register to start writing to
195 * @value: Value to write
196 * Return: 0 if OK, -ve on error
197 */
198 int rtc_write16(struct udevice *dev, unsigned int reg, u16 value);
199
200 /**
201 * rtc_read32() - Read a 32-bit value from the RTC
202 *
203 * @dev: Device to read from
204 * @reg: Offset to start reading from
205 * @valuep: Place to put the value that is read
206 * Return: 0 if OK, -ve on error
207 */
208 int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
209
210 /**
211 * rtc_write32() - Write a 32-bit value to the RTC
212 *
213 * @dev: Device to write to
214 * @reg: Register to start writing to
215 * @value: Value to write
216 * Return: 0 if OK, -ve on error
217 */
218 int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
219
220 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
221 int rtc_enable_32khz_output(int busnum, int chip_addr);
222 #endif
223
224 #else
dm_rtc_get(struct udevice * dev,struct rtc_time * time)225 static inline int dm_rtc_get(struct udevice *dev, struct rtc_time *time)
226 {
227 return -ENOSYS;
228 }
229
dm_rtc_set(struct udevice * dev,struct rtc_time * time)230 static inline int dm_rtc_set(struct udevice *dev, struct rtc_time *time)
231 {
232 return -ENOSYS;
233 }
234
dm_rtc_reset(struct udevice * dev)235 static inline int dm_rtc_reset(struct udevice *dev)
236 {
237 return -ENOSYS;
238 }
239
dm_rtc_read(struct udevice * dev,unsigned int reg,u8 * buf,unsigned int len)240 static inline int dm_rtc_read(struct udevice *dev, unsigned int reg, u8 *buf,
241 unsigned int len)
242 {
243 return -ENOSYS;
244 }
245
dm_rtc_write(struct udevice * dev,unsigned int reg,const u8 * buf,unsigned int len)246 static inline int dm_rtc_write(struct udevice *dev, unsigned int reg,
247 const u8 *buf, unsigned int len)
248 {
249 return -ENOSYS;
250 }
251
252 int rtc_get (struct rtc_time *);
253 int rtc_set (struct rtc_time *);
254 void rtc_reset (void);
255 #ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
256 void rtc_enable_32khz_output(void);
257 #endif
258
259 /**
260 * rtc_read8() - Read an 8-bit register
261 *
262 * @reg: Register to read
263 * Return: value read
264 */
265 int rtc_read8(int reg);
266
267 /**
268 * rtc_write8() - Write an 8-bit register
269 *
270 * @reg: Register to write
271 * @value: Value to write
272 */
273 void rtc_write8(int reg, uchar val);
274
275 /**
276 * rtc_read32() - Read a 32-bit value from the RTC
277 *
278 * @reg: Offset to start reading from
279 * Return: value read
280 */
281 u32 rtc_read32(int reg);
282
283 /**
284 * rtc_write32() - Write a 32-bit value to the RTC
285 *
286 * @reg: Register to start writing to
287 * @value: Value to write
288 */
289 void rtc_write32(int reg, u32 value);
290
291 /**
292 * rtc_init() - Set up the real time clock ready for use
293 */
294 void rtc_init(void);
295 #endif /* CONFIG_DM_RTC */
296
297 /**
298 * is_leap_year - Check if year is a leap year
299 *
300 * @year Year
301 * Return: 1 if leap year
302 */
is_leap_year(unsigned int year)303 static inline bool is_leap_year(unsigned int year)
304 {
305 return (!(year % 4) && (year % 100)) || !(year % 400);
306 }
307
308 /**
309 * rtc_calc_weekday() - Work out the weekday from a time
310 *
311 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK).
312 * It sets time->tm_wdaay to the correct day of the week.
313 *
314 * @time: Time to inspect. tm_wday is updated
315 * Return: 0 if OK, -EINVAL if the weekday could not be determined
316 */
317 int rtc_calc_weekday(struct rtc_time *time);
318
319 /**
320 * rtc_to_tm() - Convert a time_t value into a broken-out time
321 *
322 * The following fields are set up by this function:
323 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
324 *
325 * Note that tm_yday and tm_isdst are set to 0.
326 *
327 * @time_t: Number of seconds since 1970-01-01 00:00:00
328 * @time: Place to put the broken-out time
329 */
330 void rtc_to_tm(u64 time_t, struct rtc_time *time);
331
332 /**
333 * rtc_mktime() - Convert a broken-out time into a time64_t value
334 *
335 * The following fields need to be valid for this function to work:
336 * tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year
337 *
338 * Note that tm_wday and tm_yday are ignored.
339 *
340 * @time: Broken-out time to convert
341 * Return: corresponding time64_t value, seconds since 1970-01-01 00:00:00
342 */
343 time64_t rtc_mktime(const struct rtc_time *time);
344
345 /**
346 * rtc_month_days() - The number of days in the month
347 *
348 * @month: month (January = 0)
349 * @year: year (4 digits)
350 */
351 int rtc_month_days(unsigned int month, unsigned int year);
352
353 #endif /* _RTC_H_ */
354