1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2001, 2002, 2003
4 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
5 * Keith Outwater, keith_outwater@mvis.com`
6 * Steven Scholz, steven.scholz@imc-berlin.de
7 */
8
9 /*
10 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
11 * DS1307 and DS1338/9 Real Time Clock (RTC).
12 *
13 * based on ds1337.c
14 */
15
16 #include <common.h>
17 #include <command.h>
18 #include <dm.h>
19 #include <log.h>
20 #include <rtc.h>
21 #include <i2c.h>
22
23 enum ds_type {
24 ds_1307,
25 ds_1337,
26 ds_1339,
27 ds_1340,
28 m41t11,
29 mcp794xx,
30 };
31
32 /*
33 * RTC register addresses
34 */
35 #define RTC_SEC_REG_ADDR 0x00
36 #define RTC_MIN_REG_ADDR 0x01
37 #define RTC_HR_REG_ADDR 0x02
38 #define RTC_DAY_REG_ADDR 0x03
39 #define RTC_DATE_REG_ADDR 0x04
40 #define RTC_MON_REG_ADDR 0x05
41 #define RTC_YR_REG_ADDR 0x06
42 #define RTC_CTL_REG_ADDR 0x07
43
44 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
45
46 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
47 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
48 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
49 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */
50
51 /* MCP7941X-specific bits */
52 #define MCP7941X_BIT_ST 0x80
53 #define MCP7941X_BIT_VBATEN 0x08
54
55 #ifndef CONFIG_DM_RTC
56
57 /*---------------------------------------------------------------------*/
58 #undef DEBUG_RTC
59
60 #ifdef DEBUG_RTC
61 #define DEBUGR(fmt, args...) printf(fmt, ##args)
62 #else
63 #define DEBUGR(fmt, args...)
64 #endif
65 /*---------------------------------------------------------------------*/
66
67 #ifndef CONFIG_SYS_I2C_RTC_ADDR
68 # define CONFIG_SYS_I2C_RTC_ADDR 0x68
69 #endif
70
71 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
72 # error The DS1307 is specified only up to 100kHz!
73 #endif
74
75 static uchar rtc_read (uchar reg);
76 static void rtc_write (uchar reg, uchar val);
77
78 /*
79 * Get the current time from the RTC
80 */
rtc_get(struct rtc_time * tmp)81 int rtc_get (struct rtc_time *tmp)
82 {
83 int rel = 0;
84 uchar sec, min, hour, mday, wday, mon, year;
85
86 #ifdef CONFIG_RTC_MCP79411
87 read_rtc:
88 #endif
89 sec = rtc_read (RTC_SEC_REG_ADDR);
90 min = rtc_read (RTC_MIN_REG_ADDR);
91 hour = rtc_read (RTC_HR_REG_ADDR);
92 wday = rtc_read (RTC_DAY_REG_ADDR);
93 mday = rtc_read (RTC_DATE_REG_ADDR);
94 mon = rtc_read (RTC_MON_REG_ADDR);
95 year = rtc_read (RTC_YR_REG_ADDR);
96
97 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
98 "hr: %02x min: %02x sec: %02x\n",
99 year, mon, mday, wday, hour, min, sec);
100
101 #ifdef CONFIG_RTC_DS1307
102 if (sec & RTC_SEC_BIT_CH) {
103 printf ("### Warning: RTC oscillator has stopped\n");
104 /* clear the CH flag */
105 rtc_write (RTC_SEC_REG_ADDR,
106 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
107 rel = -1;
108 }
109 #endif
110
111 #ifdef CONFIG_RTC_MCP79411
112 /* make sure that the backup battery is enabled */
113 if (!(wday & MCP7941X_BIT_VBATEN)) {
114 rtc_write(RTC_DAY_REG_ADDR,
115 wday | MCP7941X_BIT_VBATEN);
116 }
117
118 /* clock halted? turn it on, so clock can tick. */
119 if (!(sec & MCP7941X_BIT_ST)) {
120 rtc_write(RTC_SEC_REG_ADDR, MCP7941X_BIT_ST);
121 printf("Started RTC\n");
122 goto read_rtc;
123 }
124 #endif
125
126
127 tmp->tm_sec = bcd2bin (sec & 0x7F);
128 tmp->tm_min = bcd2bin (min & 0x7F);
129 tmp->tm_hour = bcd2bin (hour & 0x3F);
130 tmp->tm_mday = bcd2bin (mday & 0x3F);
131 tmp->tm_mon = bcd2bin (mon & 0x1F);
132 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
133 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
134 tmp->tm_yday = 0;
135 tmp->tm_isdst= 0;
136
137 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
138 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
139 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
140
141 return rel;
142 }
143
144
145 /*
146 * Set the RTC
147 */
rtc_set(struct rtc_time * tmp)148 int rtc_set (struct rtc_time *tmp)
149 {
150 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
151 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
152 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
153
154 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
155 printf("WARNING: year should be between 1970 and 2069!\n");
156
157 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
158 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
159 #ifdef CONFIG_RTC_MCP79411
160 rtc_write (RTC_DAY_REG_ADDR,
161 bin2bcd (tmp->tm_wday + 1) | MCP7941X_BIT_VBATEN);
162 #else
163 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
164 #endif
165 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
166 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
167 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
168 #ifdef CONFIG_RTC_MCP79411
169 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec) | MCP7941X_BIT_ST);
170 #else
171 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
172 #endif
173
174 return 0;
175 }
176
177
178 /*
179 * Reset the RTC. We setting the date back to 1970-01-01.
180 * We also enable the oscillator output on the SQW/OUT pin and program
181 * it for 32,768 Hz output. Note that according to the datasheet, turning
182 * on the square wave output increases the current drain on the backup
183 * battery to something between 480nA and 800nA.
184 */
rtc_reset(void)185 void rtc_reset (void)
186 {
187 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
188 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
189 }
190
191
192 /*
193 * Helper functions
194 */
195
196 static
rtc_read(uchar reg)197 uchar rtc_read (uchar reg)
198 {
199 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
200 }
201
202
rtc_write(uchar reg,uchar val)203 static void rtc_write (uchar reg, uchar val)
204 {
205 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
206 }
207
208 #endif /* !CONFIG_DM_RTC */
209
210 #ifdef CONFIG_DM_RTC
ds1307_rtc_set(struct udevice * dev,const struct rtc_time * tm)211 static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
212 {
213 int ret;
214 uchar buf[7];
215 enum ds_type type = dev_get_driver_data(dev);
216
217 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
218 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
219 tm->tm_hour, tm->tm_min, tm->tm_sec);
220
221 if (tm->tm_year < 1970 || tm->tm_year > 2069)
222 printf("WARNING: year should be between 1970 and 2069!\n");
223
224 buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
225 buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
226 buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
227 buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
228 buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
229 buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
230 buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
231
232 if (type == mcp794xx) {
233 buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
234 buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
235 }
236
237 ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
238 if (ret < 0)
239 return ret;
240
241 return 0;
242 }
243
ds1307_rtc_get(struct udevice * dev,struct rtc_time * tm)244 static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
245 {
246 int ret;
247 uchar buf[7];
248 enum ds_type type = dev_get_driver_data(dev);
249
250 read_rtc:
251 ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
252 if (ret < 0)
253 return ret;
254
255 if (type == ds_1307) {
256 if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
257 printf("### Warning: RTC oscillator has stopped\n");
258 /* clear the CH flag */
259 buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
260 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
261 buf[RTC_SEC_REG_ADDR]);
262 return -1;
263 }
264 }
265
266 if (type == m41t11) {
267 /* clock halted? turn it on, so clock can tick. */
268 if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
269 buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
270 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
271 MCP7941X_BIT_ST);
272 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
273 buf[RTC_SEC_REG_ADDR]);
274 goto read_rtc;
275 }
276 }
277
278 if (type == mcp794xx) {
279 /* make sure that the backup battery is enabled */
280 if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
281 dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
282 buf[RTC_DAY_REG_ADDR] |
283 MCP7941X_BIT_VBATEN);
284 }
285
286 /* clock halted? turn it on, so clock can tick. */
287 if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
288 dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
289 MCP7941X_BIT_ST);
290 printf("Started RTC\n");
291 goto read_rtc;
292 }
293 }
294
295 tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
296 tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
297 tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
298 tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
299 tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
300 tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
301 (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
302 1900 : 2000);
303 tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
304 tm->tm_yday = 0;
305 tm->tm_isdst = 0;
306
307 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
308 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
309 tm->tm_hour, tm->tm_min, tm->tm_sec);
310
311 return 0;
312 }
313
ds1307_rtc_reset(struct udevice * dev)314 static int ds1307_rtc_reset(struct udevice *dev)
315 {
316 int ret;
317
318 /* clear Clock Halt */
319 ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
320 if (ret < 0)
321 return ret;
322 ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
323 RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
324 RTC_CTL_BIT_RS0);
325 if (ret < 0)
326 return ret;
327
328 return 0;
329 }
330
ds1307_probe(struct udevice * dev)331 static int ds1307_probe(struct udevice *dev)
332 {
333 i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
334 DM_I2C_CHIP_WR_ADDRESS);
335
336 return 0;
337 }
338
339 static const struct rtc_ops ds1307_rtc_ops = {
340 .get = ds1307_rtc_get,
341 .set = ds1307_rtc_set,
342 .reset = ds1307_rtc_reset,
343 };
344
345 static const struct udevice_id ds1307_rtc_ids[] = {
346 { .compatible = "dallas,ds1307", .data = ds_1307 },
347 { .compatible = "dallas,ds1337", .data = ds_1337 },
348 { .compatible = "dallas,ds1339", .data = ds_1339 },
349 { .compatible = "dallas,ds1340", .data = ds_1340 },
350 { .compatible = "microchip,mcp7941x", .data = mcp794xx },
351 { .compatible = "st,m41t11", .data = m41t11 },
352 { }
353 };
354
355 U_BOOT_DRIVER(rtc_ds1307) = {
356 .name = "rtc-ds1307",
357 .id = UCLASS_RTC,
358 .probe = ds1307_probe,
359 .of_match = ds1307_rtc_ids,
360 .ops = &ds1307_rtc_ops,
361 };
362 #endif /* CONFIG_DM_RTC */
363