1 /* 2 * Intersil ISL1208 rtc class driver 3 * 4 * Copyright 2005,2006 Hebert Valerio Riedel <hvr@gnu.org> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/i2c.h> 15 #include <linux/bcd.h> 16 #include <linux/rtc.h> 17 18 #define DRV_NAME "isl1208" 19 #define DRV_VERSION "0.2" 20 21 /* Register map */ 22 /* rtc section */ 23 #define ISL1208_REG_SC 0x00 24 #define ISL1208_REG_MN 0x01 25 #define ISL1208_REG_HR 0x02 26 #define ISL1208_REG_HR_MIL (1<<7) /* 24h/12h mode */ 27 #define ISL1208_REG_HR_PM (1<<5) /* PM/AM bit in 12h mode */ 28 #define ISL1208_REG_DT 0x03 29 #define ISL1208_REG_MO 0x04 30 #define ISL1208_REG_YR 0x05 31 #define ISL1208_REG_DW 0x06 32 #define ISL1208_RTC_SECTION_LEN 7 33 34 /* control/status section */ 35 #define ISL1208_REG_SR 0x07 36 #define ISL1208_REG_SR_ARST (1<<7) /* auto reset */ 37 #define ISL1208_REG_SR_XTOSCB (1<<6) /* crystal oscillator */ 38 #define ISL1208_REG_SR_WRTC (1<<4) /* write rtc */ 39 #define ISL1208_REG_SR_ALM (1<<2) /* alarm */ 40 #define ISL1208_REG_SR_BAT (1<<1) /* battery */ 41 #define ISL1208_REG_SR_RTCF (1<<0) /* rtc fail */ 42 #define ISL1208_REG_INT 0x08 43 #define ISL1208_REG_09 0x09 /* reserved */ 44 #define ISL1208_REG_ATR 0x0a 45 #define ISL1208_REG_DTR 0x0b 46 47 /* alarm section */ 48 #define ISL1208_REG_SCA 0x0c 49 #define ISL1208_REG_MNA 0x0d 50 #define ISL1208_REG_HRA 0x0e 51 #define ISL1208_REG_DTA 0x0f 52 #define ISL1208_REG_MOA 0x10 53 #define ISL1208_REG_DWA 0x11 54 #define ISL1208_ALARM_SECTION_LEN 6 55 56 /* user section */ 57 #define ISL1208_REG_USR1 0x12 58 #define ISL1208_REG_USR2 0x13 59 #define ISL1208_USR_SECTION_LEN 2 60 61 /* i2c configuration */ 62 #define ISL1208_I2C_ADDR 0xde 63 64 static unsigned short normal_i2c[] = { 65 ISL1208_I2C_ADDR>>1, I2C_CLIENT_END 66 }; 67 I2C_CLIENT_INSMOD; /* defines addr_data */ 68 69 static int isl1208_attach_adapter(struct i2c_adapter *adapter); 70 static int isl1208_detach_client(struct i2c_client *client); 71 72 static struct i2c_driver isl1208_driver = { 73 .driver = { 74 .name = DRV_NAME, 75 }, 76 .id = I2C_DRIVERID_ISL1208, 77 .attach_adapter = &isl1208_attach_adapter, 78 .detach_client = &isl1208_detach_client, 79 }; 80 81 /* block read */ 82 static int 83 isl1208_i2c_read_regs(struct i2c_client *client, u8 reg, u8 buf[], 84 unsigned len) 85 { 86 u8 reg_addr[1] = { reg }; 87 struct i2c_msg msgs[2] = { 88 { client->addr, client->flags, sizeof(reg_addr), reg_addr }, 89 { client->addr, client->flags | I2C_M_RD, len, buf } 90 }; 91 int ret; 92 93 BUG_ON(len == 0); 94 BUG_ON(reg > ISL1208_REG_USR2); 95 BUG_ON(reg + len > ISL1208_REG_USR2 + 1); 96 97 ret = i2c_transfer(client->adapter, msgs, 2); 98 if (ret > 0) 99 ret = 0; 100 return ret; 101 } 102 103 /* block write */ 104 static int 105 isl1208_i2c_set_regs(struct i2c_client *client, u8 reg, u8 const buf[], 106 unsigned len) 107 { 108 u8 i2c_buf[ISL1208_REG_USR2 + 2]; 109 struct i2c_msg msgs[1] = { 110 { client->addr, client->flags, len + 1, i2c_buf } 111 }; 112 int ret; 113 114 BUG_ON(len == 0); 115 BUG_ON(reg > ISL1208_REG_USR2); 116 BUG_ON(reg + len > ISL1208_REG_USR2 + 1); 117 118 i2c_buf[0] = reg; 119 memcpy(&i2c_buf[1], &buf[0], len); 120 121 ret = i2c_transfer(client->adapter, msgs, 1); 122 if (ret > 0) 123 ret = 0; 124 return ret; 125 } 126 127 /* simple check to see wether we have a isl1208 */ 128 static int isl1208_i2c_validate_client(struct i2c_client *client) 129 { 130 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 131 u8 zero_mask[ISL1208_RTC_SECTION_LEN] = { 132 0x80, 0x80, 0x40, 0xc0, 0xe0, 0x00, 0xf8 133 }; 134 int i; 135 int ret; 136 137 ret = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 138 if (ret < 0) 139 return ret; 140 141 for (i = 0; i < ISL1208_RTC_SECTION_LEN; ++i) { 142 if (regs[i] & zero_mask[i]) /* check if bits are cleared */ 143 return -ENODEV; 144 } 145 146 return 0; 147 } 148 149 static int isl1208_i2c_get_sr(struct i2c_client *client) 150 { 151 return i2c_smbus_read_byte_data(client, ISL1208_REG_SR) == -1 ? -EIO:0; 152 } 153 154 static int isl1208_i2c_get_atr(struct i2c_client *client) 155 { 156 int atr = i2c_smbus_read_byte_data(client, ISL1208_REG_ATR); 157 158 if (atr < 0) 159 return -EIO; 160 161 /* The 6bit value in the ATR register controls the load 162 * capacitance C_load * in steps of 0.25pF 163 * 164 * bit (1<<5) of the ATR register is inverted 165 * 166 * C_load(ATR=0x20) = 4.50pF 167 * C_load(ATR=0x00) = 12.50pF 168 * C_load(ATR=0x1f) = 20.25pF 169 * 170 */ 171 172 atr &= 0x3f; /* mask out lsb */ 173 atr ^= 1<<5; /* invert 6th bit */ 174 atr += 2*9; /* add offset of 4.5pF; unit[atr] = 0.25pF */ 175 176 return atr; 177 } 178 179 static int isl1208_i2c_get_dtr(struct i2c_client *client) 180 { 181 int dtr = i2c_smbus_read_byte_data(client, ISL1208_REG_DTR); 182 183 if (dtr < 0) 184 return -EIO; 185 186 /* dtr encodes adjustments of {-60,-40,-20,0,20,40,60} ppm */ 187 dtr = ((dtr & 0x3) * 20) * (dtr & (1<<2) ? -1 : 1); 188 189 return dtr; 190 } 191 192 static int isl1208_i2c_get_usr(struct i2c_client *client) 193 { 194 u8 buf[ISL1208_USR_SECTION_LEN] = { 0, }; 195 int ret; 196 197 ret = isl1208_i2c_read_regs (client, ISL1208_REG_USR1, buf, 198 ISL1208_USR_SECTION_LEN); 199 if (ret < 0) 200 return ret; 201 202 return (buf[1] << 8) | buf[0]; 203 } 204 205 static int isl1208_i2c_set_usr(struct i2c_client *client, u16 usr) 206 { 207 u8 buf[ISL1208_USR_SECTION_LEN]; 208 209 buf[0] = usr & 0xff; 210 buf[1] = (usr >> 8) & 0xff; 211 212 return isl1208_i2c_set_regs (client, ISL1208_REG_USR1, buf, 213 ISL1208_USR_SECTION_LEN); 214 } 215 216 static int isl1208_rtc_proc(struct device *dev, struct seq_file *seq) 217 { 218 struct i2c_client *const client = to_i2c_client(dev); 219 int sr, dtr, atr, usr; 220 221 sr = isl1208_i2c_get_sr(client); 222 if (sr < 0) { 223 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 224 return sr; 225 } 226 227 seq_printf(seq, "status_reg\t:%s%s%s%s%s%s (0x%.2x)\n", 228 (sr & ISL1208_REG_SR_RTCF) ? " RTCF" : "", 229 (sr & ISL1208_REG_SR_BAT) ? " BAT" : "", 230 (sr & ISL1208_REG_SR_ALM) ? " ALM" : "", 231 (sr & ISL1208_REG_SR_WRTC) ? " WRTC" : "", 232 (sr & ISL1208_REG_SR_XTOSCB) ? " XTOSCB" : "", 233 (sr & ISL1208_REG_SR_ARST) ? " ARST" : "", 234 sr); 235 236 seq_printf(seq, "batt_status\t: %s\n", 237 (sr & ISL1208_REG_SR_RTCF) ? "bad" : "okay"); 238 239 dtr = isl1208_i2c_get_dtr(client); 240 if (dtr >= 0 -1) 241 seq_printf(seq, "digital_trim\t: %d ppm\n", dtr); 242 243 atr = isl1208_i2c_get_atr(client); 244 if (atr >= 0) 245 seq_printf(seq, "analog_trim\t: %d.%.2d pF\n", 246 atr>>2, (atr&0x3)*25); 247 248 usr = isl1208_i2c_get_usr(client); 249 if (usr >= 0) 250 seq_printf(seq, "user_data\t: 0x%.4x\n", usr); 251 252 return 0; 253 } 254 255 256 static int isl1208_i2c_read_time(struct i2c_client *client, 257 struct rtc_time *tm) 258 { 259 int sr; 260 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 261 262 sr = isl1208_i2c_get_sr(client); 263 if (sr < 0) { 264 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 265 return -EIO; 266 } 267 268 sr = isl1208_i2c_read_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 269 if (sr < 0) { 270 dev_err(&client->dev, "%s: reading RTC section failed\n", 271 __func__); 272 return sr; 273 } 274 275 tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SC]); 276 tm->tm_min = BCD2BIN(regs[ISL1208_REG_MN]); 277 { /* HR field has a more complex interpretation */ 278 const u8 _hr = regs[ISL1208_REG_HR]; 279 if (_hr & ISL1208_REG_HR_MIL) /* 24h format */ 280 tm->tm_hour = BCD2BIN(_hr & 0x3f); 281 else { // 12h format 282 tm->tm_hour = BCD2BIN(_hr & 0x1f); 283 if (_hr & ISL1208_REG_HR_PM) /* PM flag set */ 284 tm->tm_hour += 12; 285 } 286 } 287 288 tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DT]); 289 tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MO]) - 1; /* rtc starts at 1 */ 290 tm->tm_year = BCD2BIN(regs[ISL1208_REG_YR]) + 100; 291 tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DW]); 292 293 return 0; 294 } 295 296 static int isl1208_i2c_read_alarm(struct i2c_client *client, 297 struct rtc_wkalrm *alarm) 298 { 299 struct rtc_time *const tm = &alarm->time; 300 u8 regs[ISL1208_ALARM_SECTION_LEN] = { 0, }; 301 int sr; 302 303 sr = isl1208_i2c_get_sr(client); 304 if (sr < 0) { 305 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 306 return sr; 307 } 308 309 sr = isl1208_i2c_read_regs(client, ISL1208_REG_SCA, regs, 310 ISL1208_ALARM_SECTION_LEN); 311 if (sr < 0) { 312 dev_err(&client->dev, "%s: reading alarm section failed\n", 313 __func__); 314 return sr; 315 } 316 317 /* MSB of each alarm register is an enable bit */ 318 tm->tm_sec = BCD2BIN(regs[ISL1208_REG_SCA-ISL1208_REG_SCA] & 0x7f); 319 tm->tm_min = BCD2BIN(regs[ISL1208_REG_MNA-ISL1208_REG_SCA] & 0x7f); 320 tm->tm_hour = BCD2BIN(regs[ISL1208_REG_HRA-ISL1208_REG_SCA] & 0x3f); 321 tm->tm_mday = BCD2BIN(regs[ISL1208_REG_DTA-ISL1208_REG_SCA] & 0x3f); 322 tm->tm_mon = BCD2BIN(regs[ISL1208_REG_MOA-ISL1208_REG_SCA] & 0x1f)-1; 323 tm->tm_wday = BCD2BIN(regs[ISL1208_REG_DWA-ISL1208_REG_SCA] & 0x03); 324 325 return 0; 326 } 327 328 static int isl1208_rtc_read_time(struct device *dev, struct rtc_time *tm) 329 { 330 return isl1208_i2c_read_time(to_i2c_client(dev), tm); 331 } 332 333 static int isl1208_i2c_set_time(struct i2c_client *client, 334 struct rtc_time const *tm) 335 { 336 int sr; 337 u8 regs[ISL1208_RTC_SECTION_LEN] = { 0, }; 338 339 regs[ISL1208_REG_SC] = BIN2BCD(tm->tm_sec); 340 regs[ISL1208_REG_MN] = BIN2BCD(tm->tm_min); 341 regs[ISL1208_REG_HR] = BIN2BCD(tm->tm_hour) | ISL1208_REG_HR_MIL; 342 343 regs[ISL1208_REG_DT] = BIN2BCD(tm->tm_mday); 344 regs[ISL1208_REG_MO] = BIN2BCD(tm->tm_mon + 1); 345 regs[ISL1208_REG_YR] = BIN2BCD(tm->tm_year - 100); 346 347 regs[ISL1208_REG_DW] = BIN2BCD(tm->tm_wday & 7); 348 349 sr = isl1208_i2c_get_sr(client); 350 if (sr < 0) { 351 dev_err(&client->dev, "%s: reading SR failed\n", __func__); 352 return sr; 353 } 354 355 /* set WRTC */ 356 sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR, 357 sr | ISL1208_REG_SR_WRTC); 358 if (sr < 0) { 359 dev_err(&client->dev, "%s: writing SR failed\n", __func__); 360 return sr; 361 } 362 363 /* write RTC registers */ 364 sr = isl1208_i2c_set_regs(client, 0, regs, ISL1208_RTC_SECTION_LEN); 365 if (sr < 0) { 366 dev_err(&client->dev, "%s: writing RTC section failed\n", 367 __func__); 368 return sr; 369 } 370 371 /* clear WRTC again */ 372 sr = i2c_smbus_write_byte_data (client, ISL1208_REG_SR, 373 sr & ~ISL1208_REG_SR_WRTC); 374 if (sr < 0) { 375 dev_err(&client->dev, "%s: writing SR failed\n", __func__); 376 return sr; 377 } 378 379 return 0; 380 } 381 382 383 static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm) 384 { 385 return isl1208_i2c_set_time(to_i2c_client(dev), tm); 386 } 387 388 static int isl1208_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) 389 { 390 return isl1208_i2c_read_alarm(to_i2c_client(dev), alarm); 391 } 392 393 static const struct rtc_class_ops isl1208_rtc_ops = { 394 .proc = isl1208_rtc_proc, 395 .read_time = isl1208_rtc_read_time, 396 .set_time = isl1208_rtc_set_time, 397 .read_alarm = isl1208_rtc_read_alarm, 398 //.set_alarm = isl1208_rtc_set_alarm, 399 }; 400 401 /* sysfs interface */ 402 403 static ssize_t isl1208_sysfs_show_atrim(struct device *dev, 404 struct device_attribute *attr, 405 char *buf) 406 { 407 int atr; 408 409 atr = isl1208_i2c_get_atr(to_i2c_client(dev)); 410 if (atr < 0) 411 return atr; 412 413 return sprintf(buf, "%d.%.2d pF\n", atr>>2, (atr&0x3)*25); 414 } 415 static DEVICE_ATTR(atrim, S_IRUGO, isl1208_sysfs_show_atrim, NULL); 416 417 static ssize_t isl1208_sysfs_show_dtrim(struct device *dev, 418 struct device_attribute *attr, 419 char *buf) 420 { 421 int dtr; 422 423 dtr = isl1208_i2c_get_dtr(to_i2c_client(dev)); 424 if (dtr < 0) 425 return dtr; 426 427 return sprintf(buf, "%d ppm\n", dtr); 428 } 429 static DEVICE_ATTR(dtrim, S_IRUGO, isl1208_sysfs_show_dtrim, NULL); 430 431 static ssize_t isl1208_sysfs_show_usr(struct device *dev, 432 struct device_attribute *attr, 433 char *buf) 434 { 435 int usr; 436 437 usr = isl1208_i2c_get_usr(to_i2c_client(dev)); 438 if (usr < 0) 439 return usr; 440 441 return sprintf(buf, "0x%.4x\n", usr); 442 } 443 444 static ssize_t isl1208_sysfs_store_usr(struct device *dev, 445 struct device_attribute *attr, 446 const char *buf, size_t count) 447 { 448 int usr = -1; 449 450 if (buf[0] == '0' && (buf[1] == 'x' || buf[1] == 'X')) { 451 if (sscanf(buf, "%x", &usr) != 1) 452 return -EINVAL; 453 } else { 454 if (sscanf(buf, "%d", &usr) != 1) 455 return -EINVAL; 456 } 457 458 if (usr < 0 || usr > 0xffff) 459 return -EINVAL; 460 461 return isl1208_i2c_set_usr(to_i2c_client(dev), usr) ? -EIO : count; 462 } 463 static DEVICE_ATTR(usr, S_IRUGO | S_IWUSR, isl1208_sysfs_show_usr, 464 isl1208_sysfs_store_usr); 465 466 static int 467 isl1208_probe(struct i2c_adapter *adapter, int addr, int kind) 468 { 469 int rc = 0; 470 struct i2c_client *new_client = NULL; 471 struct rtc_device *rtc = NULL; 472 473 if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) { 474 rc = -ENODEV; 475 goto failout; 476 } 477 478 new_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); 479 if (new_client == NULL) { 480 rc = -ENOMEM; 481 goto failout; 482 } 483 484 new_client->addr = addr; 485 new_client->adapter = adapter; 486 new_client->driver = &isl1208_driver; 487 new_client->flags = 0; 488 strcpy(new_client->name, DRV_NAME); 489 490 if (kind < 0) { 491 rc = isl1208_i2c_validate_client(new_client); 492 if (rc < 0) 493 goto failout; 494 } 495 496 rc = i2c_attach_client(new_client); 497 if (rc < 0) 498 goto failout; 499 500 dev_info(&new_client->dev, 501 "chip found, driver version " DRV_VERSION "\n"); 502 503 rtc = rtc_device_register(isl1208_driver.driver.name, 504 &new_client->dev, 505 &isl1208_rtc_ops, THIS_MODULE); 506 507 if (IS_ERR(rtc)) { 508 rc = PTR_ERR(rtc); 509 goto failout_detach; 510 } 511 512 i2c_set_clientdata(new_client, rtc); 513 514 rc = isl1208_i2c_get_sr(new_client); 515 if (rc < 0) { 516 dev_err(&new_client->dev, "reading status failed\n"); 517 goto failout_unregister; 518 } 519 520 if (rc & ISL1208_REG_SR_RTCF) 521 dev_warn(&new_client->dev, "rtc power failure detected, " 522 "please set clock.\n"); 523 524 rc = device_create_file(&new_client->dev, &dev_attr_atrim); 525 if (rc < 0) 526 goto failout_unregister; 527 rc = device_create_file(&new_client->dev, &dev_attr_dtrim); 528 if (rc < 0) 529 goto failout_atrim; 530 rc = device_create_file(&new_client->dev, &dev_attr_usr); 531 if (rc < 0) 532 goto failout_dtrim; 533 534 return 0; 535 536 failout_dtrim: 537 device_remove_file(&new_client->dev, &dev_attr_dtrim); 538 failout_atrim: 539 device_remove_file(&new_client->dev, &dev_attr_atrim); 540 failout_unregister: 541 rtc_device_unregister(rtc); 542 failout_detach: 543 i2c_detach_client(new_client); 544 failout: 545 kfree(new_client); 546 return rc; 547 } 548 549 static int 550 isl1208_attach_adapter (struct i2c_adapter *adapter) 551 { 552 return i2c_probe(adapter, &addr_data, isl1208_probe); 553 } 554 555 static int 556 isl1208_detach_client(struct i2c_client *client) 557 { 558 int rc; 559 struct rtc_device *const rtc = i2c_get_clientdata(client); 560 561 if (rtc) 562 rtc_device_unregister(rtc); /* do we need to kfree? */ 563 564 rc = i2c_detach_client(client); 565 if (rc) 566 return rc; 567 568 kfree(client); 569 570 return 0; 571 } 572 573 /* module management */ 574 575 static int __init isl1208_init(void) 576 { 577 return i2c_add_driver(&isl1208_driver); 578 } 579 580 static void __exit isl1208_exit(void) 581 { 582 i2c_del_driver(&isl1208_driver); 583 } 584 585 MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); 586 MODULE_DESCRIPTION("Intersil ISL1208 RTC driver"); 587 MODULE_LICENSE("GPL"); 588 MODULE_VERSION(DRV_VERSION); 589 590 module_init(isl1208_init); 591 module_exit(isl1208_exit); 592