2 * (C) Copyright 2001, 2002, 2003
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 * Keith Outwater, keith_outwater@mvis.com`
5 * Steven Scholz, steven.scholz@imc-berlin.de
7 * SPDX-License-Identifier: GPL-2.0+
11 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
12 * DS1307 and DS1338/9 Real Time Clock (RTC).
31 * RTC register addresses
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
42 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
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 */
49 /* MCP7941X-specific bits */
50 #define MCP7941X_BIT_ST 0x80
51 #define MCP7941X_BIT_VBATEN 0x08
55 #if defined(CONFIG_CMD_DATE)
57 /*---------------------------------------------------------------------*/
61 #define DEBUGR(fmt, args...) printf(fmt, ##args)
63 #define DEBUGR(fmt, args...)
65 /*---------------------------------------------------------------------*/
67 #ifndef CONFIG_SYS_I2C_RTC_ADDR
68 # define CONFIG_SYS_I2C_RTC_ADDR 0x68
71 #if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
72 # error The DS1307 is specified only up to 100kHz!
75 static uchar
rtc_read (uchar reg
);
76 static void rtc_write (uchar reg
, uchar val
);
79 * Get the current time from the RTC
81 int rtc_get (struct rtc_time
*tmp
)
84 uchar sec
, min
, hour
, mday
, wday
, mon
, year
;
86 #ifdef CONFIG_RTC_MCP79411
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
);
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
);
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
);
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
);
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");
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);
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
);
148 int rtc_set (struct rtc_time
*tmp
)
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
);
154 if (tmp
->tm_year
< 1970 || tmp
->tm_year
> 2069)
155 printf("WARNING: year should be between 1970 and 2069!\n");
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
);
163 rtc_write (RTC_DAY_REG_ADDR
, bin2bcd (tmp
->tm_wday
+ 1));
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
);
171 rtc_write (RTC_SEC_REG_ADDR
, bin2bcd (tmp
->tm_sec
));
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.
185 void rtc_reset (void)
189 rtc_write (RTC_SEC_REG_ADDR
, 0x00); /* clearing Clock Halt */
190 rtc_write (RTC_CTL_REG_ADDR
, RTC_CTL_BIT_SQWE
| RTC_CTL_BIT_RS1
| RTC_CTL_BIT_RS0
);
201 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
202 tmp
.tm_year
, tmp
.tm_mon
, tmp
.tm_mday
,
203 tmp
.tm_hour
, tmp
.tm_min
, tmp
.tm_sec
);
214 uchar
rtc_read (uchar reg
)
216 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR
, reg
));
220 static void rtc_write (uchar reg
, uchar val
)
222 i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR
, reg
, val
);
225 #endif /* CONFIG_CMD_DATE*/
227 #endif /* !CONFIG_DM_RTC */
230 static int ds1307_rtc_set(struct udevice
*dev
, const struct rtc_time
*tm
)
234 enum ds_type type
= dev_get_driver_data(dev
);
236 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
237 tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
, tm
->tm_wday
,
238 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
240 if (tm
->tm_year
< 1970 || tm
->tm_year
> 2069)
241 printf("WARNING: year should be between 1970 and 2069!\n");
243 buf
[RTC_YR_REG_ADDR
] = bin2bcd(tm
->tm_year
% 100);
244 buf
[RTC_MON_REG_ADDR
] = bin2bcd(tm
->tm_mon
);
245 buf
[RTC_DAY_REG_ADDR
] = bin2bcd(tm
->tm_wday
+ 1);
246 buf
[RTC_DATE_REG_ADDR
] = bin2bcd(tm
->tm_mday
);
247 buf
[RTC_HR_REG_ADDR
] = bin2bcd(tm
->tm_hour
);
248 buf
[RTC_MIN_REG_ADDR
] = bin2bcd(tm
->tm_min
);
249 buf
[RTC_SEC_REG_ADDR
] = bin2bcd(tm
->tm_sec
);
251 if (type
== mcp794xx
) {
252 buf
[RTC_DAY_REG_ADDR
] |= MCP7941X_BIT_VBATEN
;
253 buf
[RTC_SEC_REG_ADDR
] |= MCP7941X_BIT_ST
;
256 ret
= dm_i2c_write(dev
, 0, buf
, sizeof(buf
));
263 static int ds1307_rtc_get(struct udevice
*dev
, struct rtc_time
*tm
)
267 enum ds_type type
= dev_get_driver_data(dev
);
270 ret
= dm_i2c_read(dev
, 0, buf
, sizeof(buf
));
274 if (type
== ds_1307
) {
275 if (buf
[RTC_SEC_REG_ADDR
] & RTC_SEC_BIT_CH
) {
276 printf("### Warning: RTC oscillator has stopped\n");
277 /* clear the CH flag */
278 buf
[RTC_SEC_REG_ADDR
] &= ~RTC_SEC_BIT_CH
;
279 dm_i2c_reg_write(dev
, RTC_SEC_REG_ADDR
,
280 buf
[RTC_SEC_REG_ADDR
]);
285 if (type
== mcp794xx
) {
286 /* make sure that the backup battery is enabled */
287 if (!(buf
[RTC_DAY_REG_ADDR
] & MCP7941X_BIT_VBATEN
)) {
288 dm_i2c_reg_write(dev
, RTC_DAY_REG_ADDR
,
289 buf
[RTC_DAY_REG_ADDR
] |
290 MCP7941X_BIT_VBATEN
);
293 /* clock halted? turn it on, so clock can tick. */
294 if (!(buf
[RTC_SEC_REG_ADDR
] & MCP7941X_BIT_ST
)) {
295 dm_i2c_reg_write(dev
, RTC_SEC_REG_ADDR
,
297 printf("Started RTC\n");
302 tm
->tm_sec
= bcd2bin(buf
[RTC_SEC_REG_ADDR
] & 0x7F);
303 tm
->tm_min
= bcd2bin(buf
[RTC_MIN_REG_ADDR
] & 0x7F);
304 tm
->tm_hour
= bcd2bin(buf
[RTC_HR_REG_ADDR
] & 0x3F);
305 tm
->tm_mday
= bcd2bin(buf
[RTC_DATE_REG_ADDR
] & 0x3F);
306 tm
->tm_mon
= bcd2bin(buf
[RTC_MON_REG_ADDR
] & 0x1F);
307 tm
->tm_year
= bcd2bin(buf
[RTC_YR_REG_ADDR
]) +
308 (bcd2bin(buf
[RTC_YR_REG_ADDR
]) >= 70 ?
310 tm
->tm_wday
= bcd2bin((buf
[RTC_DAY_REG_ADDR
] - 1) & 0x07);
314 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
315 tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
, tm
->tm_wday
,
316 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
321 static int ds1307_rtc_reset(struct udevice
*dev
)
324 struct rtc_time tmp
= {
333 /* clear Clock Halt */
334 ret
= dm_i2c_reg_write(dev
, RTC_SEC_REG_ADDR
, 0x00);
337 ret
= dm_i2c_reg_write(dev
, RTC_CTL_REG_ADDR
,
338 RTC_CTL_BIT_SQWE
| RTC_CTL_BIT_RS1
|
343 ret
= ds1307_rtc_set(dev
, &tmp
);
347 debug("RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
348 tmp
.tm_year
, tmp
.tm_mon
, tmp
.tm_mday
,
349 tmp
.tm_hour
, tmp
.tm_min
, tmp
.tm_sec
);
354 static int ds1307_probe(struct udevice
*dev
)
356 i2c_set_chip_flags(dev
, DM_I2C_CHIP_RD_ADDRESS
|
357 DM_I2C_CHIP_WR_ADDRESS
);
362 static const struct rtc_ops ds1307_rtc_ops
= {
363 .get
= ds1307_rtc_get
,
364 .set
= ds1307_rtc_set
,
365 .reset
= ds1307_rtc_reset
,
368 static const struct udevice_id ds1307_rtc_ids
[] = {
369 { .compatible
= "dallas,ds1307", .data
= ds_1307
},
370 { .compatible
= "dallas,ds1337", .data
= ds_1337
},
371 { .compatible
= "dallas,ds1340", .data
= ds_1340
},
372 { .compatible
= "microchip,mcp7941x", .data
= mcp794xx
},
376 U_BOOT_DRIVER(rtc_ds1307
) = {
377 .name
= "rtc-ds1307",
379 .probe
= ds1307_probe
,
380 .of_match
= ds1307_rtc_ids
,
381 .ops
= &ds1307_rtc_ops
,
383 #endif /* CONFIG_DM_RTC */