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