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