1 /* 2 * Micro Crystal RV-3029C2 rtc class driver 3 * 4 * Author: Gregory Hermant <gregory.hermant@calao-systems.com> 5 * 6 * based on previously existing rtc class drivers 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 * 12 * NOTE: Currently this driver only supports the bare minimum for read 13 * and write the RTC and alarms. The extra features provided by this chip 14 * (trickle charger, eeprom, T° compensation) are unavailable. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/i2c.h> 19 #include <linux/bcd.h> 20 #include <linux/rtc.h> 21 22 /* Register map */ 23 /* control section */ 24 #define RV3029C2_ONOFF_CTRL 0x00 25 #define RV3029C2_IRQ_CTRL 0x01 26 #define RV3029C2_IRQ_CTRL_AIE (1 << 0) 27 #define RV3029C2_IRQ_FLAGS 0x02 28 #define RV3029C2_IRQ_FLAGS_AF (1 << 0) 29 #define RV3029C2_STATUS 0x03 30 #define RV3029C2_STATUS_VLOW1 (1 << 2) 31 #define RV3029C2_STATUS_VLOW2 (1 << 3) 32 #define RV3029C2_STATUS_SR (1 << 4) 33 #define RV3029C2_STATUS_PON (1 << 5) 34 #define RV3029C2_STATUS_EEBUSY (1 << 7) 35 #define RV3029C2_RST_CTRL 0x04 36 #define RV3029C2_CONTROL_SECTION_LEN 0x05 37 38 /* watch section */ 39 #define RV3029C2_W_SEC 0x08 40 #define RV3029C2_W_MINUTES 0x09 41 #define RV3029C2_W_HOURS 0x0A 42 #define RV3029C2_REG_HR_12_24 (1<<6) /* 24h/12h mode */ 43 #define RV3029C2_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ 44 #define RV3029C2_W_DATE 0x0B 45 #define RV3029C2_W_DAYS 0x0C 46 #define RV3029C2_W_MONTHS 0x0D 47 #define RV3029C2_W_YEARS 0x0E 48 #define RV3029C2_WATCH_SECTION_LEN 0x07 49 50 /* alarm section */ 51 #define RV3029C2_A_SC 0x10 52 #define RV3029C2_A_MN 0x11 53 #define RV3029C2_A_HR 0x12 54 #define RV3029C2_A_DT 0x13 55 #define RV3029C2_A_DW 0x14 56 #define RV3029C2_A_MO 0x15 57 #define RV3029C2_A_YR 0x16 58 #define RV3029C2_ALARM_SECTION_LEN 0x07 59 60 /* timer section */ 61 #define RV3029C2_TIMER_LOW 0x18 62 #define RV3029C2_TIMER_HIGH 0x19 63 64 /* temperature section */ 65 #define RV3029C2_TEMP_PAGE 0x20 66 67 /* eeprom data section */ 68 #define RV3029C2_E2P_EEDATA1 0x28 69 #define RV3029C2_E2P_EEDATA2 0x29 70 71 /* eeprom control section */ 72 #define RV3029C2_CONTROL_E2P_EECTRL 0x30 73 #define RV3029C2_TRICKLE_1K (1<<0) /* 1K resistance */ 74 #define RV3029C2_TRICKLE_5K (1<<1) /* 5K resistance */ 75 #define RV3029C2_TRICKLE_20K (1<<2) /* 20K resistance */ 76 #define RV3029C2_TRICKLE_80K (1<<3) /* 80K resistance */ 77 #define RV3029C2_CONTROL_E2P_XTALOFFSET 0x31 78 #define RV3029C2_CONTROL_E2P_QCOEF 0x32 79 #define RV3029C2_CONTROL_E2P_TURNOVER 0x33 80 81 /* user ram section */ 82 #define RV3029C2_USR1_RAM_PAGE 0x38 83 #define RV3029C2_USR1_SECTION_LEN 0x04 84 #define RV3029C2_USR2_RAM_PAGE 0x3C 85 #define RV3029C2_USR2_SECTION_LEN 0x04 86 87 static int 88 rv3029c2_i2c_read_regs(struct i2c_client *client, u8 reg, u8 *buf, 89 unsigned len) 90 { 91 int ret; 92 93 if ((reg > RV3029C2_USR1_RAM_PAGE + 7) || 94 (reg + len > RV3029C2_USR1_RAM_PAGE + 8)) 95 return -EINVAL; 96 97 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf); 98 if (ret < 0) 99 return ret; 100 if (ret < len) 101 return -EIO; 102 return 0; 103 } 104 105 static int 106 rv3029c2_i2c_write_regs(struct i2c_client *client, u8 reg, u8 const buf[], 107 unsigned len) 108 { 109 if ((reg > RV3029C2_USR1_RAM_PAGE + 7) || 110 (reg + len > RV3029C2_USR1_RAM_PAGE + 8)) 111 return -EINVAL; 112 113 return i2c_smbus_write_i2c_block_data(client, reg, len, buf); 114 } 115 116 static int 117 rv3029c2_i2c_get_sr(struct i2c_client *client, u8 *buf) 118 { 119 int ret = rv3029c2_i2c_read_regs(client, RV3029C2_STATUS, buf, 1); 120 121 if (ret < 0) 122 return -EIO; 123 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); 124 return 0; 125 } 126 127 static int 128 rv3029c2_i2c_set_sr(struct i2c_client *client, u8 val) 129 { 130 u8 buf[1]; 131 int sr; 132 133 buf[0] = val; 134 sr = rv3029c2_i2c_write_regs(client, RV3029C2_STATUS, buf, 1); 135 dev_dbg(&client->dev, "status = 0x%.2x (%d)\n", buf[0], buf[0]); 136 if (sr < 0) 137 return -EIO; 138 return 0; 139 } 140 141 static int 142 rv3029c2_i2c_read_time(struct i2c_client *client, struct rtc_time *tm) 143 { 144 u8 buf[1]; 145 int ret; 146 u8 regs[RV3029C2_WATCH_SECTION_LEN] = { 0, }; 147 148 ret = rv3029c2_i2c_get_sr(client, buf); 149 if (ret < 0) { 150 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 151 return -EIO; 152 } 153 154 ret = rv3029c2_i2c_read_regs(client, RV3029C2_W_SEC , regs, 155 RV3029C2_WATCH_SECTION_LEN); 156 if (ret < 0) { 157 dev_err(&client->dev, "%s: reading RTC section failed\n", 158 __func__); 159 return ret; 160 } 161 162 tm->tm_sec = bcd2bin(regs[RV3029C2_W_SEC-RV3029C2_W_SEC]); 163 tm->tm_min = bcd2bin(regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC]); 164 165 /* HR field has a more complex interpretation */ 166 { 167 const u8 _hr = regs[RV3029C2_W_HOURS-RV3029C2_W_SEC]; 168 if (_hr & RV3029C2_REG_HR_12_24) { 169 /* 12h format */ 170 tm->tm_hour = bcd2bin(_hr & 0x1f); 171 if (_hr & RV3029C2_REG_HR_PM) /* PM flag set */ 172 tm->tm_hour += 12; 173 } else /* 24h format */ 174 tm->tm_hour = bcd2bin(_hr & 0x3f); 175 } 176 177 tm->tm_mday = bcd2bin(regs[RV3029C2_W_DATE-RV3029C2_W_SEC]); 178 tm->tm_mon = bcd2bin(regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC]) - 1; 179 tm->tm_year = bcd2bin(regs[RV3029C2_W_YEARS-RV3029C2_W_SEC]) + 100; 180 tm->tm_wday = bcd2bin(regs[RV3029C2_W_DAYS-RV3029C2_W_SEC]) - 1; 181 182 return 0; 183 } 184 185 static int rv3029c2_rtc_read_time(struct device *dev, struct rtc_time *tm) 186 { 187 return rv3029c2_i2c_read_time(to_i2c_client(dev), tm); 188 } 189 190 static int 191 rv3029c2_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) 192 { 193 struct rtc_time *const tm = &alarm->time; 194 int ret; 195 u8 regs[8]; 196 197 ret = rv3029c2_i2c_get_sr(client, regs); 198 if (ret < 0) { 199 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 200 return -EIO; 201 } 202 203 ret = rv3029c2_i2c_read_regs(client, RV3029C2_A_SC, regs, 204 RV3029C2_ALARM_SECTION_LEN); 205 206 if (ret < 0) { 207 dev_err(&client->dev, "%s: reading alarm section failed\n", 208 __func__); 209 return ret; 210 } 211 212 tm->tm_sec = bcd2bin(regs[RV3029C2_A_SC-RV3029C2_A_SC] & 0x7f); 213 tm->tm_min = bcd2bin(regs[RV3029C2_A_MN-RV3029C2_A_SC] & 0x7f); 214 tm->tm_hour = bcd2bin(regs[RV3029C2_A_HR-RV3029C2_A_SC] & 0x3f); 215 tm->tm_mday = bcd2bin(regs[RV3029C2_A_DT-RV3029C2_A_SC] & 0x3f); 216 tm->tm_mon = bcd2bin(regs[RV3029C2_A_MO-RV3029C2_A_SC] & 0x1f) - 1; 217 tm->tm_year = bcd2bin(regs[RV3029C2_A_YR-RV3029C2_A_SC] & 0x7f) + 100; 218 tm->tm_wday = bcd2bin(regs[RV3029C2_A_DW-RV3029C2_A_SC] & 0x07) - 1; 219 220 return 0; 221 } 222 223 static int 224 rv3029c2_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 225 { 226 return rv3029c2_i2c_read_alarm(to_i2c_client(dev), alarm); 227 } 228 229 static int rv3029c2_rtc_i2c_alarm_set_irq(struct i2c_client *client, 230 int enable) 231 { 232 int ret; 233 u8 buf[1]; 234 235 /* enable AIE irq */ 236 ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_CTRL, buf, 1); 237 if (ret < 0) { 238 dev_err(&client->dev, "can't read INT reg\n"); 239 return ret; 240 } 241 if (enable) 242 buf[0] |= RV3029C2_IRQ_CTRL_AIE; 243 else 244 buf[0] &= ~RV3029C2_IRQ_CTRL_AIE; 245 246 ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_CTRL, buf, 1); 247 if (ret < 0) { 248 dev_err(&client->dev, "can't set INT reg\n"); 249 return ret; 250 } 251 252 return 0; 253 } 254 255 static int rv3029c2_rtc_i2c_set_alarm(struct i2c_client *client, 256 struct rtc_wkalrm *alarm) 257 { 258 struct rtc_time *const tm = &alarm->time; 259 int ret; 260 u8 regs[8]; 261 262 /* 263 * The clock has an 8 bit wide bcd-coded register (they never learn) 264 * for the year. tm_year is an offset from 1900 and we are interested 265 * in the 2000-2099 range, so any value less than 100 is invalid. 266 */ 267 if (tm->tm_year < 100) 268 return -EINVAL; 269 270 ret = rv3029c2_i2c_get_sr(client, regs); 271 if (ret < 0) { 272 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 273 return -EIO; 274 } 275 regs[RV3029C2_A_SC-RV3029C2_A_SC] = bin2bcd(tm->tm_sec & 0x7f); 276 regs[RV3029C2_A_MN-RV3029C2_A_SC] = bin2bcd(tm->tm_min & 0x7f); 277 regs[RV3029C2_A_HR-RV3029C2_A_SC] = bin2bcd(tm->tm_hour & 0x3f); 278 regs[RV3029C2_A_DT-RV3029C2_A_SC] = bin2bcd(tm->tm_mday & 0x3f); 279 regs[RV3029C2_A_MO-RV3029C2_A_SC] = bin2bcd((tm->tm_mon & 0x1f) - 1); 280 regs[RV3029C2_A_DW-RV3029C2_A_SC] = bin2bcd((tm->tm_wday & 7) - 1); 281 regs[RV3029C2_A_YR-RV3029C2_A_SC] = bin2bcd((tm->tm_year & 0x7f) - 100); 282 283 ret = rv3029c2_i2c_write_regs(client, RV3029C2_A_SC, regs, 284 RV3029C2_ALARM_SECTION_LEN); 285 if (ret < 0) 286 return ret; 287 288 if (alarm->enabled) { 289 u8 buf[1]; 290 291 /* clear AF flag */ 292 ret = rv3029c2_i2c_read_regs(client, RV3029C2_IRQ_FLAGS, 293 buf, 1); 294 if (ret < 0) { 295 dev_err(&client->dev, "can't read alarm flag\n"); 296 return ret; 297 } 298 buf[0] &= ~RV3029C2_IRQ_FLAGS_AF; 299 ret = rv3029c2_i2c_write_regs(client, RV3029C2_IRQ_FLAGS, 300 buf, 1); 301 if (ret < 0) { 302 dev_err(&client->dev, "can't set alarm flag\n"); 303 return ret; 304 } 305 /* enable AIE irq */ 306 ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 1); 307 if (ret) 308 return ret; 309 310 dev_dbg(&client->dev, "alarm IRQ armed\n"); 311 } else { 312 /* disable AIE irq */ 313 ret = rv3029c2_rtc_i2c_alarm_set_irq(client, 0); 314 if (ret) 315 return ret; 316 317 dev_dbg(&client->dev, "alarm IRQ disabled\n"); 318 } 319 320 return 0; 321 } 322 323 static int rv3029c2_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 324 { 325 return rv3029c2_rtc_i2c_set_alarm(to_i2c_client(dev), alarm); 326 } 327 328 static int 329 rv3029c2_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) 330 { 331 u8 regs[8]; 332 int ret; 333 334 /* 335 * The clock has an 8 bit wide bcd-coded register (they never learn) 336 * for the year. tm_year is an offset from 1900 and we are interested 337 * in the 2000-2099 range, so any value less than 100 is invalid. 338 */ 339 if (tm->tm_year < 100) 340 return -EINVAL; 341 342 regs[RV3029C2_W_SEC-RV3029C2_W_SEC] = bin2bcd(tm->tm_sec); 343 regs[RV3029C2_W_MINUTES-RV3029C2_W_SEC] = bin2bcd(tm->tm_min); 344 regs[RV3029C2_W_HOURS-RV3029C2_W_SEC] = bin2bcd(tm->tm_hour); 345 regs[RV3029C2_W_DATE-RV3029C2_W_SEC] = bin2bcd(tm->tm_mday); 346 regs[RV3029C2_W_MONTHS-RV3029C2_W_SEC] = bin2bcd(tm->tm_mon+1); 347 regs[RV3029C2_W_DAYS-RV3029C2_W_SEC] = bin2bcd((tm->tm_wday & 7)+1); 348 regs[RV3029C2_W_YEARS-RV3029C2_W_SEC] = bin2bcd(tm->tm_year - 100); 349 350 ret = rv3029c2_i2c_write_regs(client, RV3029C2_W_SEC, regs, 351 RV3029C2_WATCH_SECTION_LEN); 352 if (ret < 0) 353 return ret; 354 355 ret = rv3029c2_i2c_get_sr(client, regs); 356 if (ret < 0) { 357 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 358 return ret; 359 } 360 /* clear PON bit */ 361 ret = rv3029c2_i2c_set_sr(client, (regs[0] & ~RV3029C2_STATUS_PON)); 362 if (ret < 0) { 363 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 364 return ret; 365 } 366 367 return 0; 368 } 369 370 static int rv3029c2_rtc_set_time(struct device *dev, struct rtc_time *tm) 371 { 372 return rv3029c2_i2c_set_time(to_i2c_client(dev), tm); 373 } 374 375 static const struct rtc_class_ops rv3029c2_rtc_ops = { 376 .read_time = rv3029c2_rtc_read_time, 377 .set_time = rv3029c2_rtc_set_time, 378 .read_alarm = rv3029c2_rtc_read_alarm, 379 .set_alarm = rv3029c2_rtc_set_alarm, 380 }; 381 382 static struct i2c_device_id rv3029c2_id[] = { 383 { "rv3029c2", 0 }, 384 { } 385 }; 386 MODULE_DEVICE_TABLE(i2c, rv3029c2_id); 387 388 static int rv3029c2_probe(struct i2c_client *client, 389 const struct i2c_device_id *id) 390 { 391 struct rtc_device *rtc; 392 int rc = 0; 393 u8 buf[1]; 394 395 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_EMUL)) 396 return -ENODEV; 397 398 rc = rv3029c2_i2c_get_sr(client, buf); 399 if (rc < 0) { 400 dev_err(&client->dev, "reading status failed\n"); 401 return rc; 402 } 403 404 rtc = devm_rtc_device_register(&client->dev, client->name, 405 &rv3029c2_rtc_ops, THIS_MODULE); 406 407 if (IS_ERR(rtc)) 408 return PTR_ERR(rtc); 409 410 i2c_set_clientdata(client, rtc); 411 412 return 0; 413 } 414 415 static struct i2c_driver rv3029c2_driver = { 416 .driver = { 417 .name = "rtc-rv3029c2", 418 }, 419 .probe = rv3029c2_probe, 420 .id_table = rv3029c2_id, 421 }; 422 423 module_i2c_driver(rv3029c2_driver); 424 425 MODULE_AUTHOR("Gregory Hermant <gregory.hermant@calao-systems.com>"); 426 MODULE_DESCRIPTION("Micro Crystal RV3029C2 RTC driver"); 427 MODULE_LICENSE("GPL"); 428