1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Intersil ISL1208 rtc class driver 4 * 5 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org> 6 */ 7 8 #include <linux/bcd.h> 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/i2c.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/of_irq.h> 15 #include <linux/rtc.h> 16 17 /* Register map */ 18 /* rtc section */ 19 #define ISL1208_REG_SC 0x00 20 #define ISL1208_REG_MN 0x01 21 #define ISL1208_REG_HR 0x02 22 #define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */ 23 #define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ 24 #define ISL1208_REG_DT 0x03 25 #define ISL1208_REG_MO 0x04 26 #define ISL1208_REG_YR 0x05 27 #define ISL1208_REG_DW 0x06 28 #define ISL1208_RTC_SECTION_LEN 7 29 30 /* control/status section */ 31 #define ISL1208_REG_SR 0x07 32 #define ISL1208_REG_SR_ARST (1<<7) /* auto reset */ 33 #define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */ 34 #define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */ 35 #define ISL1208_REG_SR_EVT (1<<3) /* event */ 36 #define ISL1208_REG_SR_ALM (1<<2) /* alarm */ 37 #define ISL1208_REG_SR_BAT (1<<1) /* battery */ 38 #define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */ 39 #define ISL1208_REG_INT 0x08 40 #define ISL1208_REG_INT_ALME (1<<6) /* alarm enable */ 41 #define ISL1208_REG_INT_IM (1<<7) /* interrupt/alarm mode */ 42 #define ISL1219_REG_EV 0x09 43 #define ISL1219_REG_EV_EVEN (1<<4) /* event detection enable */ 44 #define ISL1219_REG_EV_EVIENB (1<<7) /* event in pull-up disable */ 45 #define ISL1208_REG_ATR 0x0a 46 #define ISL1208_REG_DTR 0x0b 47 48 /* alarm section */ 49 #define ISL1208_REG_SCA 0x0c 50 #define ISL1208_REG_MNA 0x0d 51 #define ISL1208_REG_HRA 0x0e 52 #define ISL1208_REG_DTA 0x0f 53 #define ISL1208_REG_MOA 0x10 54 #define ISL1208_REG_DWA 0x11 55 #define ISL1208_ALARM_SECTION_LEN 6 56 57 /* user section */ 58 #define ISL1208_REG_USR1 0x12 59 #define ISL1208_REG_USR2 0x13 60 #define ISL1208_USR_SECTION_LEN 2 61 62 /* event section */ 63 #define ISL1219_REG_SCT 0x14 64 #define ISL1219_REG_MNT 0x15 65 #define ISL1219_REG_HRT 0x16 66 #define ISL1219_REG_DTT 0x17 67 #define ISL1219_REG_MOT 0x18 68 #define ISL1219_REG_YRT 0x19 69 #define ISL1219_EVT_SECTION_LEN 6 70 71 static struct i2c_driver isl1208_driver; 72 73 /* Chip capabilities table */ 74 struct isl1208_config { 75 unsigned int nvmem_length; 76 unsigned has_tamper:1; 77 unsigned has_timestamp:1; 78 unsigned has_inverted_osc_bit:1; 79 }; 80 81 static const struct isl1208_config config_isl1208 = { 82 .nvmem_length = 2, 83 .has_tamper = false, 84 .has_timestamp = false 85 }; 86 87 static const struct isl1208_config config_isl1209 = { 88 .nvmem_length = 2, 89 .has_tamper = true, 90 .has_timestamp = false 91 }; 92 93 static const struct isl1208_config config_isl1218 = { 94 .nvmem_length = 8, 95 .has_tamper = false, 96 .has_timestamp = false 97 }; 98 99 static const struct isl1208_config config_isl1219 = { 100 .nvmem_length = 2, 101 .has_tamper = true, 102 .has_timestamp = true 103 }; 104 105 static const struct isl1208_config config_raa215300_a0 = { 106 .nvmem_length = 2, 107 .has_tamper = false, 108 .has_timestamp = false, 109 .has_inverted_osc_bit = true 110 }; 111 112 static const struct i2c_device_id isl1208_id[] = { 113 { "isl1208", .driver_data = (kernel_ulong_t)&config_isl1208 }, 114 { "isl1209", .driver_data = (kernel_ulong_t)&config_isl1209 }, 115 { "isl1218", .driver_data = (kernel_ulong_t)&config_isl1218 }, 116 { "isl1219", .driver_data = (kernel_ulong_t)&config_isl1219 }, 117 { "raa215300_a0", .driver_data = (kernel_ulong_t)&config_raa215300_a0 }, 118 { } 119 }; 120 MODULE_DEVICE_TABLE(i2c, isl1208_id); 121 122 static const __maybe_unused struct of_device_id isl1208_of_match[] = { 123 { .compatible = "isil,isl1208", .data = &config_isl1208 }, 124 { .compatible = "isil,isl1209", .data = &config_isl1209 }, 125 { .compatible = "isil,isl1218", .data = &config_isl1218 }, 126 { .compatible = "isil,isl1219", .data = &config_isl1219 }, 127 { } 128 }; 129 MODULE_DEVICE_TABLE(of, isl1208_of_match); 130 131 /* Device state */ 132 struct isl1208_state { 133 struct nvmem_config nvmem_config; 134 struct rtc_device *rtc; 135 const struct isl1208_config *config; 136 }; 137 138 /* block read */ 139 static int 140 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[], 141 unsigned len) 142 { 143 int ret; 144 145 WARN_ON(reg > ISL1219_REG_YRT); 146 WARN_ON(reg + len > ISL1219_REG_YRT + 1); 147 148 ret = i2c_smbus_read_i2c_block_data(client, reg, len, buf); 149 return (ret < 0) ? ret : 0; 150 } 151 152 /* block write */ 153 static int 154 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[], 155 unsigned len) 156 { 157 int ret; 158 159 WARN_ON(reg > ISL1219_REG_YRT); 160 WARN_ON(reg + len > ISL1219_REG_YRT + 1); 161 162 ret = i2c_smbus_write_i2c_block_data(client, reg, len, buf); 163 return (ret < 0) ? ret : 0; 164 } 165 166 /* simple check to see whether we have a isl1208 */ 167 static int 168 isl1208_i2c_validate_client(struct i2c_client *client) 169 { 170 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 171 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = { 172 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8 173 }; 174 int i; 175 int ret; 176 177 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 178 if (ret < 0) 179 return ret; 180 181 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) { 182 if (regs[i] & zero_mask[i]) /* check if bits are cleared */ 183 return -ENODEV; 184 } 185 186 return 0; 187 } 188 189 static int isl1208_set_xtoscb(struct i2c_client *client, int sr, int xtosb_val) 190 { 191 /* Do nothing if bit is already set to desired value */ 192 if (!!(sr & ISL1208_REG_SR_XTOSCB) == xtosb_val) 193 return 0; 194 195 if (xtosb_val) 196 sr |= ISL1208_REG_SR_XTOSCB; 197 else 198 sr &= ~ISL1208_REG_SR_XTOSCB; 199 200 return i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr); 201 } 202 203 static int 204 isl1208_i2c_get_sr(struct i2c_client *client) 205 { 206 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR); 207 } 208 209 static int 210 isl1208_i2c_get_atr(struct i2c_client *client) 211 { 212 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR); 213 if (atr < 0) 214 return atr; 215 216 /* The 6bit value in the ATR register controls the load 217 * capacitance C_load * in steps of 0.25pF 218 * 219 * bit (1<<5) of the ATR register is inverted 220 * 221 * C_load(ATR=0x20) = 4.50pF 222 * C_load(ATR=0x00) = 12.50pF 223 * C_load(ATR=0x1f) = 20.25pF 224 * 225 */ 226 227 atr &= 0x3f; /* mask out lsb */ 228 atr ^= 1 << 5; /* invert 6th bit */ 229 atr += 2 * 9; /* add offset of 4.5pF; unit[atr] = 0.25pF */ 230 231 return atr; 232 } 233 234 /* returns adjustment value + 100 */ 235 static int 236 isl1208_i2c_get_dtr(struct i2c_client *client) 237 { 238 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR); 239 if (dtr < 0) 240 return -EIO; 241 242 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */ 243 dtr = ((dtr & 0x3) * 20) * (dtr & (1 << 2) ? -1 : 1); 244 245 return dtr + 100; 246 } 247 248 static int 249 isl1208_i2c_get_usr(struct i2c_client *client) 250 { 251 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, }; 252 int ret; 253 254 ret = isl1208_i2c_read_regs(client, ISL1208_REG_USR1, buf, 255 ISL1208_USR_SECTION_LEN); 256 if (ret < 0) 257 return ret; 258 259 return (buf[1] << 8) | buf[0]; 260 } 261 262 static int 263 isl1208_i2c_set_usr(struct i2c_client *client, u16 usr) 264 { 265 u8 buf[ISL1208_USR_SECTION_LEN]; 266 267 buf[0] = usr & 0xff; 268 buf[1] = (usr >> 8) & 0xff; 269 270 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1, buf, 271 ISL1208_USR_SECTION_LEN); 272 } 273 274 static int 275 isl1208_rtc_toggle_alarm(struct i2c_client *client, int enable) 276 { 277 int icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT); 278 279 if (icr < 0) { 280 dev_err(&client->dev, "%s: reading INT failed\n", __func__); 281 return icr; 282 } 283 284 if (enable) 285 icr |= ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM; 286 else 287 icr &= ~(ISL1208_REG_INT_ALME | ISL1208_REG_INT_IM); 288 289 icr = i2c_smbus_write_byte_data(client, ISL1208_REG_INT, icr); 290 if (icr < 0) { 291 dev_err(&client->dev, "%s: writing INT failed\n", __func__); 292 return icr; 293 } 294 295 return 0; 296 } 297 298 static int 299 isl1208_rtc_proc(struct device *dev, struct seq_file *seq) 300 { 301 struct i2c_client *const client = to_i2c_client(dev); 302 int sr, dtr, atr, usr; 303 304 sr = isl1208_i2c_get_sr(client); 305 if (sr < 0) { 306 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 307 return sr; 308 } 309 310 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n", 311 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "", 312 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "", 313 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "", 314 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "", 315 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "", 316 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", sr); 317 318 seq_printf(seq, "batt_status\t: %s\n", 319 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay"); 320 321 dtr = isl1208_i2c_get_dtr(client); 322 if (dtr >= 0) 323 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr - 100); 324 325 atr = isl1208_i2c_get_atr(client); 326 if (atr >= 0) 327 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n", 328 atr >> 2, (atr & 0x3) * 25); 329 330 usr = isl1208_i2c_get_usr(client); 331 if (usr >= 0) 332 seq_printf(seq, "user_data\t: 0x%.4x\n", usr); 333 334 return 0; 335 } 336 337 static int 338 isl1208_i2c_read_time(struct i2c_client *client, struct rtc_time *tm) 339 { 340 int sr; 341 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 342 343 sr = isl1208_i2c_get_sr(client); 344 if (sr < 0) { 345 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 346 return -EIO; 347 } 348 349 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 350 if (sr < 0) { 351 dev_err(&client->dev, "%s: reading RTC section failed\n", 352 __func__); 353 return sr; 354 } 355 356 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SC]); 357 tm->tm_min = bcd2bin(regs[ISL1208_REG_MN]); 358 359 /* HR field has a more complex interpretation */ 360 { 361 const u8 _hr = regs[ISL1208_REG_HR]; 362 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */ 363 tm->tm_hour = bcd2bin(_hr & 0x3f); 364 else { 365 /* 12h format */ 366 tm->tm_hour = bcd2bin(_hr & 0x1f); 367 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */ 368 tm->tm_hour += 12; 369 } 370 } 371 372 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DT]); 373 tm->tm_mon = bcd2bin(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */ 374 tm->tm_year = bcd2bin(regs[ISL1208_REG_YR]) + 100; 375 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DW]); 376 377 return 0; 378 } 379 380 static int 381 isl1208_i2c_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) 382 { 383 struct rtc_time *const tm = &alarm->time; 384 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, }; 385 int icr, yr, sr = isl1208_i2c_get_sr(client); 386 387 if (sr < 0) { 388 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 389 return sr; 390 } 391 392 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs, 393 ISL1208_ALARM_SECTION_LEN); 394 if (sr < 0) { 395 dev_err(&client->dev, "%s: reading alarm section failed\n", 396 __func__); 397 return sr; 398 } 399 400 /* MSB of each alarm register is an enable bit */ 401 tm->tm_sec = bcd2bin(regs[ISL1208_REG_SCA - ISL1208_REG_SCA] & 0x7f); 402 tm->tm_min = bcd2bin(regs[ISL1208_REG_MNA - ISL1208_REG_SCA] & 0x7f); 403 tm->tm_hour = bcd2bin(regs[ISL1208_REG_HRA - ISL1208_REG_SCA] & 0x3f); 404 tm->tm_mday = bcd2bin(regs[ISL1208_REG_DTA - ISL1208_REG_SCA] & 0x3f); 405 tm->tm_mon = 406 bcd2bin(regs[ISL1208_REG_MOA - ISL1208_REG_SCA] & 0x1f) - 1; 407 tm->tm_wday = bcd2bin(regs[ISL1208_REG_DWA - ISL1208_REG_SCA] & 0x03); 408 409 /* The alarm doesn't store the year so get it from the rtc section */ 410 yr = i2c_smbus_read_byte_data(client, ISL1208_REG_YR); 411 if (yr < 0) { 412 dev_err(&client->dev, "%s: reading RTC YR failed\n", __func__); 413 return yr; 414 } 415 tm->tm_year = bcd2bin(yr) + 100; 416 417 icr = i2c_smbus_read_byte_data(client, ISL1208_REG_INT); 418 if (icr < 0) { 419 dev_err(&client->dev, "%s: reading INT failed\n", __func__); 420 return icr; 421 } 422 alarm->enabled = !!(icr & ISL1208_REG_INT_ALME); 423 424 return 0; 425 } 426 427 static int 428 isl1208_i2c_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alarm) 429 { 430 struct rtc_time *alarm_tm = &alarm->time; 431 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, }; 432 const int offs = ISL1208_REG_SCA; 433 struct rtc_time rtc_tm; 434 int err, enable; 435 436 err = isl1208_i2c_read_time(client, &rtc_tm); 437 if (err) 438 return err; 439 440 /* If the alarm time is before the current time disable the alarm */ 441 if (!alarm->enabled || rtc_tm_sub(alarm_tm, &rtc_tm) <= 0) 442 enable = 0x00; 443 else 444 enable = 0x80; 445 446 /* Program the alarm and enable it for each setting */ 447 regs[ISL1208_REG_SCA - offs] = bin2bcd(alarm_tm->tm_sec) | enable; 448 regs[ISL1208_REG_MNA - offs] = bin2bcd(alarm_tm->tm_min) | enable; 449 regs[ISL1208_REG_HRA - offs] = bin2bcd(alarm_tm->tm_hour) | 450 ISL1208_REG_HR_MIL | enable; 451 452 regs[ISL1208_REG_DTA - offs] = bin2bcd(alarm_tm->tm_mday) | enable; 453 regs[ISL1208_REG_MOA - offs] = bin2bcd(alarm_tm->tm_mon + 1) | enable; 454 regs[ISL1208_REG_DWA - offs] = bin2bcd(alarm_tm->tm_wday & 7) | enable; 455 456 /* write ALARM registers */ 457 err = isl1208_i2c_set_regs(client, offs, regs, 458 ISL1208_ALARM_SECTION_LEN); 459 if (err < 0) { 460 dev_err(&client->dev, "%s: writing ALARM section failed\n", 461 __func__); 462 return err; 463 } 464 465 err = isl1208_rtc_toggle_alarm(client, enable); 466 if (err) 467 return err; 468 469 return 0; 470 } 471 472 static int 473 isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm) 474 { 475 return isl1208_i2c_read_time(to_i2c_client(dev), tm); 476 } 477 478 static int 479 isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) 480 { 481 int sr; 482 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 483 484 /* The clock has an 8 bit wide bcd-coded register (they never learn) 485 * for the year. tm_year is an offset from 1900 and we are interested 486 * in the 2000-2099 range, so any value less than 100 is invalid. 487 */ 488 if (tm->tm_year < 100) 489 return -EINVAL; 490 491 regs[ISL1208_REG_SC] = bin2bcd(tm->tm_sec); 492 regs[ISL1208_REG_MN] = bin2bcd(tm->tm_min); 493 regs[ISL1208_REG_HR] = bin2bcd(tm->tm_hour) | ISL1208_REG_HR_MIL; 494 495 regs[ISL1208_REG_DT] = bin2bcd(tm->tm_mday); 496 regs[ISL1208_REG_MO] = bin2bcd(tm->tm_mon + 1); 497 regs[ISL1208_REG_YR] = bin2bcd(tm->tm_year - 100); 498 499 regs[ISL1208_REG_DW] = bin2bcd(tm->tm_wday & 7); 500 501 sr = isl1208_i2c_get_sr(client); 502 if (sr < 0) { 503 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 504 return sr; 505 } 506 507 /* set WRTC */ 508 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, 509 sr | ISL1208_REG_SR_WRTC); 510 if (sr < 0) { 511 dev_err(&client->dev, "%s: writing SR failed\n", __func__); 512 return sr; 513 } 514 515 /* write RTC registers */ 516 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 517 if (sr < 0) { 518 dev_err(&client->dev, "%s: writing RTC section failed\n", 519 __func__); 520 return sr; 521 } 522 523 /* clear WRTC again */ 524 sr = isl1208_i2c_get_sr(client); 525 if (sr < 0) { 526 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 527 return sr; 528 } 529 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, 530 sr & ~ISL1208_REG_SR_WRTC); 531 if (sr < 0) { 532 dev_err(&client->dev, "%s: writing SR failed\n", __func__); 533 return sr; 534 } 535 536 return 0; 537 } 538 539 static int 540 isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm) 541 { 542 return isl1208_i2c_set_time(to_i2c_client(dev), tm); 543 } 544 545 static int 546 isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 547 { 548 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm); 549 } 550 551 static int 552 isl1208_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) 553 { 554 return isl1208_i2c_set_alarm(to_i2c_client(dev), alarm); 555 } 556 557 static ssize_t timestamp0_store(struct device *dev, 558 struct device_attribute *attr, 559 const char *buf, size_t count) 560 { 561 struct i2c_client *client = to_i2c_client(dev->parent); 562 int sr; 563 564 sr = isl1208_i2c_get_sr(client); 565 if (sr < 0) { 566 dev_err(dev, "%s: reading SR failed\n", __func__); 567 return sr; 568 } 569 570 sr &= ~ISL1208_REG_SR_EVT; 571 572 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr); 573 if (sr < 0) 574 dev_err(dev, "%s: writing SR failed\n", 575 __func__); 576 577 return count; 578 }; 579 580 static ssize_t timestamp0_show(struct device *dev, 581 struct device_attribute *attr, char *buf) 582 { 583 struct i2c_client *client = to_i2c_client(dev->parent); 584 u8 regs[ISL1219_EVT_SECTION_LEN] = { 0, }; 585 struct rtc_time tm; 586 int sr; 587 588 sr = isl1208_i2c_get_sr(client); 589 if (sr < 0) { 590 dev_err(dev, "%s: reading SR failed\n", __func__); 591 return sr; 592 } 593 594 if (!(sr & ISL1208_REG_SR_EVT)) 595 return 0; 596 597 sr = isl1208_i2c_read_regs(client, ISL1219_REG_SCT, regs, 598 ISL1219_EVT_SECTION_LEN); 599 if (sr < 0) { 600 dev_err(dev, "%s: reading event section failed\n", 601 __func__); 602 return 0; 603 } 604 605 /* MSB of each alarm register is an enable bit */ 606 tm.tm_sec = bcd2bin(regs[ISL1219_REG_SCT - ISL1219_REG_SCT] & 0x7f); 607 tm.tm_min = bcd2bin(regs[ISL1219_REG_MNT - ISL1219_REG_SCT] & 0x7f); 608 tm.tm_hour = bcd2bin(regs[ISL1219_REG_HRT - ISL1219_REG_SCT] & 0x3f); 609 tm.tm_mday = bcd2bin(regs[ISL1219_REG_DTT - ISL1219_REG_SCT] & 0x3f); 610 tm.tm_mon = 611 bcd2bin(regs[ISL1219_REG_MOT - ISL1219_REG_SCT] & 0x1f) - 1; 612 tm.tm_year = bcd2bin(regs[ISL1219_REG_YRT - ISL1219_REG_SCT]) + 100; 613 614 sr = rtc_valid_tm(&tm); 615 if (sr) 616 return sr; 617 618 return sprintf(buf, "%llu\n", 619 (unsigned long long)rtc_tm_to_time64(&tm)); 620 }; 621 622 static DEVICE_ATTR_RW(timestamp0); 623 624 static irqreturn_t 625 isl1208_rtc_interrupt(int irq, void *data) 626 { 627 unsigned long timeout = jiffies + msecs_to_jiffies(1000); 628 struct i2c_client *client = data; 629 struct isl1208_state *isl1208 = i2c_get_clientdata(client); 630 int handled = 0, sr, err; 631 632 if (!isl1208->config->has_tamper) { 633 /* 634 * The INT# output is pulled low 250ms after the alarm is 635 * triggered. After the INT# output is pulled low, it is low for 636 * at least 250ms, even if the correct action is taken to clear 637 * it. It is impossible to clear ALM if it is still active. The 638 * host must wait for the RTC to progress past the alarm time 639 * plus the 250ms delay before clearing ALM. 640 */ 641 msleep(250); 642 } 643 644 /* 645 * I2C reads get NAK'ed if we read straight away after an interrupt? 646 * Using a mdelay/msleep didn't seem to help either, so we work around 647 * this by continually trying to read the register for a short time. 648 */ 649 while (1) { 650 sr = isl1208_i2c_get_sr(client); 651 if (sr >= 0) 652 break; 653 654 if (time_after(jiffies, timeout)) { 655 dev_err(&client->dev, "%s: reading SR failed\n", 656 __func__); 657 return sr; 658 } 659 } 660 661 if (sr & ISL1208_REG_SR_ALM) { 662 dev_dbg(&client->dev, "alarm!\n"); 663 664 rtc_update_irq(isl1208->rtc, 1, RTC_IRQF | RTC_AF); 665 666 /* Disable the alarm */ 667 err = isl1208_rtc_toggle_alarm(client, 0); 668 if (err) 669 return err; 670 671 fsleep(275); 672 673 /* Clear the alarm */ 674 sr &= ~ISL1208_REG_SR_ALM; 675 sr = i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr); 676 if (sr < 0) 677 dev_err(&client->dev, "%s: writing SR failed\n", 678 __func__); 679 else 680 handled = 1; 681 } 682 683 if (isl1208->config->has_tamper && (sr & ISL1208_REG_SR_EVT)) { 684 dev_warn(&client->dev, "event detected"); 685 handled = 1; 686 if (isl1208->config->has_timestamp) 687 sysfs_notify(&isl1208->rtc->dev.kobj, NULL, 688 dev_attr_timestamp0.attr.name); 689 } 690 691 return handled ? IRQ_HANDLED : IRQ_NONE; 692 } 693 694 static const struct rtc_class_ops isl1208_rtc_ops = { 695 .proc = isl1208_rtc_proc, 696 .read_time = isl1208_rtc_read_time, 697 .set_time = isl1208_rtc_set_time, 698 .read_alarm = isl1208_rtc_read_alarm, 699 .set_alarm = isl1208_rtc_set_alarm, 700 }; 701 702 /* sysfs interface */ 703 704 static ssize_t 705 isl1208_sysfs_show_atrim(struct device *dev, 706 struct device_attribute *attr, char *buf) 707 { 708 int atr = isl1208_i2c_get_atr(to_i2c_client(dev->parent)); 709 if (atr < 0) 710 return atr; 711 712 return sprintf(buf, "%d.%.2d pF\n", atr >> 2, (atr & 0x3) * 25); 713 } 714 715 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL); 716 717 static ssize_t 718 isl1208_sysfs_show_dtrim(struct device *dev, 719 struct device_attribute *attr, char *buf) 720 { 721 int dtr = isl1208_i2c_get_dtr(to_i2c_client(dev->parent)); 722 if (dtr < 0) 723 return dtr; 724 725 return sprintf(buf, "%d ppm\n", dtr - 100); 726 } 727 728 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL); 729 730 static ssize_t 731 isl1208_sysfs_show_usr(struct device *dev, 732 struct device_attribute *attr, char *buf) 733 { 734 int usr = isl1208_i2c_get_usr(to_i2c_client(dev->parent)); 735 if (usr < 0) 736 return usr; 737 738 return sprintf(buf, "0x%.4x\n", usr); 739 } 740 741 static ssize_t 742 isl1208_sysfs_store_usr(struct device *dev, 743 struct device_attribute *attr, 744 const char *buf, size_t count) 745 { 746 int usr = -1; 747 748 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) { 749 if (sscanf(buf, "%x", &usr) != 1) 750 return -EINVAL; 751 } else { 752 if (sscanf(buf, "%d", &usr) != 1) 753 return -EINVAL; 754 } 755 756 if (usr < 0 || usr > 0xffff) 757 return -EINVAL; 758 759 if (isl1208_i2c_set_usr(to_i2c_client(dev->parent), usr)) 760 return -EIO; 761 762 return count; 763 } 764 765 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr, 766 isl1208_sysfs_store_usr); 767 768 static struct attribute *isl1208_rtc_attrs[] = { 769 &dev_attr_atrim.attr, 770 &dev_attr_dtrim.attr, 771 &dev_attr_usr.attr, 772 NULL 773 }; 774 775 static const struct attribute_group isl1208_rtc_sysfs_files = { 776 .attrs = isl1208_rtc_attrs, 777 }; 778 779 static struct attribute *isl1219_rtc_attrs[] = { 780 &dev_attr_timestamp0.attr, 781 NULL 782 }; 783 784 static const struct attribute_group isl1219_rtc_sysfs_files = { 785 .attrs = isl1219_rtc_attrs, 786 }; 787 788 static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf, 789 size_t count) 790 { 791 struct isl1208_state *isl1208 = priv; 792 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent); 793 794 /* nvmem sanitizes offset/count for us, but count==0 is possible */ 795 if (!count) 796 return count; 797 798 return isl1208_i2c_read_regs(client, ISL1208_REG_USR1 + off, buf, 799 count); 800 } 801 802 static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf, 803 size_t count) 804 { 805 struct isl1208_state *isl1208 = priv; 806 struct i2c_client *client = to_i2c_client(isl1208->rtc->dev.parent); 807 808 /* nvmem sanitizes off/count for us, but count==0 is possible */ 809 if (!count) 810 return count; 811 812 return isl1208_i2c_set_regs(client, ISL1208_REG_USR1 + off, buf, 813 count); 814 } 815 816 static const struct nvmem_config isl1208_nvmem_config = { 817 .name = "isl1208_nvram", 818 .word_size = 1, 819 .stride = 1, 820 /* .size from chip specific config */ 821 .reg_read = isl1208_nvmem_read, 822 .reg_write = isl1208_nvmem_write, 823 }; 824 825 static int isl1208_setup_irq(struct i2c_client *client, int irq) 826 { 827 int rc = devm_request_threaded_irq(&client->dev, irq, NULL, 828 isl1208_rtc_interrupt, 829 IRQF_SHARED | IRQF_ONESHOT, 830 isl1208_driver.driver.name, 831 client); 832 if (!rc) { 833 device_init_wakeup(&client->dev, 1); 834 enable_irq_wake(irq); 835 } else { 836 dev_err(&client->dev, 837 "Unable to request irq %d, no alarm support\n", 838 irq); 839 } 840 return rc; 841 } 842 843 static int 844 isl1208_clk_present(struct i2c_client *client, const char *name) 845 { 846 struct clk *clk; 847 848 clk = devm_clk_get_optional(&client->dev, name); 849 if (IS_ERR(clk)) 850 return PTR_ERR(clk); 851 852 return !!clk; 853 } 854 855 static int 856 isl1208_probe(struct i2c_client *client) 857 { 858 struct isl1208_state *isl1208; 859 int evdet_irq = -1; 860 int xtosb_val = 0; 861 int rc = 0; 862 int sr; 863 864 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) 865 return -ENODEV; 866 867 if (isl1208_i2c_validate_client(client) < 0) 868 return -ENODEV; 869 870 /* Allocate driver state, point i2c client data to it */ 871 isl1208 = devm_kzalloc(&client->dev, sizeof(*isl1208), GFP_KERNEL); 872 if (!isl1208) 873 return -ENOMEM; 874 i2c_set_clientdata(client, isl1208); 875 876 /* Determine which chip we have */ 877 isl1208->config = i2c_get_match_data(client); 878 if (!isl1208->config) 879 return -ENODEV; 880 881 rc = isl1208_clk_present(client, "xin"); 882 if (rc < 0) 883 return rc; 884 885 if (!rc) { 886 rc = isl1208_clk_present(client, "clkin"); 887 if (rc < 0) 888 return rc; 889 890 if (rc) 891 xtosb_val = 1; 892 } 893 894 isl1208->rtc = devm_rtc_allocate_device(&client->dev); 895 if (IS_ERR(isl1208->rtc)) 896 return PTR_ERR(isl1208->rtc); 897 898 isl1208->rtc->ops = &isl1208_rtc_ops; 899 900 /* Setup nvmem configuration in driver state struct */ 901 isl1208->nvmem_config = isl1208_nvmem_config; 902 isl1208->nvmem_config.size = isl1208->config->nvmem_length; 903 isl1208->nvmem_config.priv = isl1208; 904 905 sr = isl1208_i2c_get_sr(client); 906 if (sr < 0) { 907 dev_err(&client->dev, "reading status failed\n"); 908 return sr; 909 } 910 911 if (isl1208->config->has_inverted_osc_bit) 912 xtosb_val = !xtosb_val; 913 914 rc = isl1208_set_xtoscb(client, sr, xtosb_val); 915 if (rc) 916 return rc; 917 918 if (sr & ISL1208_REG_SR_RTCF) 919 dev_warn(&client->dev, "rtc power failure detected, " 920 "please set clock.\n"); 921 922 if (isl1208->config->has_tamper) { 923 struct device_node *np = client->dev.of_node; 924 u32 evienb; 925 926 rc = i2c_smbus_read_byte_data(client, ISL1219_REG_EV); 927 if (rc < 0) { 928 dev_err(&client->dev, "failed to read EV reg\n"); 929 return rc; 930 } 931 rc |= ISL1219_REG_EV_EVEN; 932 if (!of_property_read_u32(np, "isil,ev-evienb", &evienb)) { 933 if (evienb) 934 rc |= ISL1219_REG_EV_EVIENB; 935 else 936 rc &= ~ISL1219_REG_EV_EVIENB; 937 } 938 rc = i2c_smbus_write_byte_data(client, ISL1219_REG_EV, rc); 939 if (rc < 0) { 940 dev_err(&client->dev, "could not enable tamper detection\n"); 941 return rc; 942 } 943 evdet_irq = of_irq_get_byname(np, "evdet"); 944 } 945 if (isl1208->config->has_timestamp) { 946 rc = rtc_add_group(isl1208->rtc, &isl1219_rtc_sysfs_files); 947 if (rc) 948 return rc; 949 } 950 951 rc = rtc_add_group(isl1208->rtc, &isl1208_rtc_sysfs_files); 952 if (rc) 953 return rc; 954 955 if (client->irq > 0) { 956 rc = isl1208_setup_irq(client, client->irq); 957 if (rc) 958 return rc; 959 } else { 960 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, isl1208->rtc->features); 961 } 962 963 if (evdet_irq > 0 && evdet_irq != client->irq) 964 rc = isl1208_setup_irq(client, evdet_irq); 965 if (rc) 966 return rc; 967 968 rc = devm_rtc_nvmem_register(isl1208->rtc, &isl1208->nvmem_config); 969 if (rc) 970 return rc; 971 972 return devm_rtc_register_device(isl1208->rtc); 973 } 974 975 static struct i2c_driver isl1208_driver = { 976 .driver = { 977 .name = "rtc-isl1208", 978 .of_match_table = of_match_ptr(isl1208_of_match), 979 }, 980 .probe = isl1208_probe, 981 .id_table = isl1208_id, 982 }; 983 984 module_i2c_driver(isl1208_driver); 985 986 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); 987 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver"); 988 MODULE_LICENSE("GPL"); 989