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