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 */ 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 */ 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 */ 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 196 uchar rtc_read (uchar reg) 197 { 198 return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg)); 199 } 200 201 202 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 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 } 244 245 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 } 302 303 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 } 319 320 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