1 /* 2 * I2C client/driver for the ST M41T80 family of i2c rtc chips. 3 * 4 * Author: Alexander Bigga <ab@mycable.de> 5 * 6 * Based on m41t00.c by Mark A. Greer <mgreer@mvista.com> 7 * 8 * 2006 (c) mycable GmbH 9 * 10 * This program is free software; you can redistribute it and/or modify 11 * it under the terms of the GNU General Public License version 2 as 12 * published by the Free Software Foundation. 13 * 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/bcd.h> 19 #include <linux/i2c.h> 20 #include <linux/init.h> 21 #include <linux/kernel.h> 22 #include <linux/module.h> 23 #include <linux/rtc.h> 24 #include <linux/slab.h> 25 #include <linux/mutex.h> 26 #include <linux/string.h> 27 #ifdef CONFIG_RTC_DRV_M41T80_WDT 28 #include <linux/fs.h> 29 #include <linux/ioctl.h> 30 #include <linux/miscdevice.h> 31 #include <linux/reboot.h> 32 #include <linux/watchdog.h> 33 #endif 34 35 #define M41T80_REG_SSEC 0 36 #define M41T80_REG_SEC 1 37 #define M41T80_REG_MIN 2 38 #define M41T80_REG_HOUR 3 39 #define M41T80_REG_WDAY 4 40 #define M41T80_REG_DAY 5 41 #define M41T80_REG_MON 6 42 #define M41T80_REG_YEAR 7 43 #define M41T80_REG_ALARM_MON 0xa 44 #define M41T80_REG_ALARM_DAY 0xb 45 #define M41T80_REG_ALARM_HOUR 0xc 46 #define M41T80_REG_ALARM_MIN 0xd 47 #define M41T80_REG_ALARM_SEC 0xe 48 #define M41T80_REG_FLAGS 0xf 49 #define M41T80_REG_SQW 0x13 50 51 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) 52 #define M41T80_ALARM_REG_SIZE \ 53 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) 54 55 #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */ 56 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ 57 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ 58 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ 59 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ 60 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ 61 #define M41T80_WATCHDOG_RB2 (1 << 7) /* RB: Watchdog resolution */ 62 #define M41T80_WATCHDOG_RB1 (1 << 1) /* RB: Watchdog resolution */ 63 #define M41T80_WATCHDOG_RB0 (1 << 0) /* RB: Watchdog resolution */ 64 65 #define M41T80_FEATURE_HT (1 << 0) /* Halt feature */ 66 #define M41T80_FEATURE_BL (1 << 1) /* Battery low indicator */ 67 #define M41T80_FEATURE_SQ (1 << 2) /* Squarewave feature */ 68 #define M41T80_FEATURE_WD (1 << 3) /* Extra watchdog resolution */ 69 #define M41T80_FEATURE_SQ_ALT (1 << 4) /* RSx bits are in reg 4 */ 70 71 static DEFINE_MUTEX(m41t80_rtc_mutex); 72 static const struct i2c_device_id m41t80_id[] = { 73 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT }, 74 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD }, 75 { "m41t80", M41T80_FEATURE_SQ }, 76 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ}, 77 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 78 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 79 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 80 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 81 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 82 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 83 { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT }, 84 { } 85 }; 86 MODULE_DEVICE_TABLE(i2c, m41t80_id); 87 88 struct m41t80_data { 89 u8 features; 90 struct rtc_device *rtc; 91 }; 92 93 static int m41t80_get_datetime(struct i2c_client *client, 94 struct rtc_time *tm) 95 { 96 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; 97 struct i2c_msg msgs[] = { 98 { 99 .addr = client->addr, 100 .flags = 0, 101 .len = 1, 102 .buf = dt_addr, 103 }, 104 { 105 .addr = client->addr, 106 .flags = I2C_M_RD, 107 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 108 .buf = buf + M41T80_REG_SEC, 109 }, 110 }; 111 112 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 113 dev_err(&client->dev, "read error\n"); 114 return -EIO; 115 } 116 117 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f); 118 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f); 119 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f); 120 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f); 121 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; 122 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1; 123 124 /* assume 20YY not 19YY, and ignore the Century Bit */ 125 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100; 126 return rtc_valid_tm(tm); 127 } 128 129 /* Sets the given date and time to the real time clock. */ 130 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) 131 { 132 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; 133 u8 *buf = &wbuf[1]; 134 u8 dt_addr[1] = { M41T80_REG_SEC }; 135 struct i2c_msg msgs_in[] = { 136 { 137 .addr = client->addr, 138 .flags = 0, 139 .len = 1, 140 .buf = dt_addr, 141 }, 142 { 143 .addr = client->addr, 144 .flags = I2C_M_RD, 145 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 146 .buf = buf + M41T80_REG_SEC, 147 }, 148 }; 149 struct i2c_msg msgs[] = { 150 { 151 .addr = client->addr, 152 .flags = 0, 153 .len = 1 + M41T80_DATETIME_REG_SIZE, 154 .buf = wbuf, 155 }, 156 }; 157 158 /* Read current reg values into buf[1..7] */ 159 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 160 dev_err(&client->dev, "read error\n"); 161 return -EIO; 162 } 163 164 wbuf[0] = 0; /* offset into rtc's regs */ 165 /* Merge time-data and register flags into buf[0..7] */ 166 buf[M41T80_REG_SSEC] = 0; 167 buf[M41T80_REG_SEC] = 168 bin2bcd(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); 169 buf[M41T80_REG_MIN] = 170 bin2bcd(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); 171 buf[M41T80_REG_HOUR] = 172 bin2bcd(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f); 173 buf[M41T80_REG_WDAY] = 174 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); 175 buf[M41T80_REG_DAY] = 176 bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); 177 buf[M41T80_REG_MON] = 178 bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); 179 180 /* assume 20YY not 19YY */ 181 if (tm->tm_year < 100 || tm->tm_year > 199) { 182 dev_err(&client->dev, "Year must be between 2000 and 2099. It's %d.\n", 183 tm->tm_year + 1900); 184 return -EINVAL; 185 } 186 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100); 187 188 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 189 dev_err(&client->dev, "write error\n"); 190 return -EIO; 191 } 192 return 0; 193 } 194 195 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) 196 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) 197 { 198 struct i2c_client *client = to_i2c_client(dev); 199 struct m41t80_data *clientdata = i2c_get_clientdata(client); 200 u8 reg; 201 202 if (clientdata->features & M41T80_FEATURE_BL) { 203 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 204 seq_printf(seq, "battery\t\t: %s\n", 205 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); 206 } 207 return 0; 208 } 209 #else 210 #define m41t80_rtc_proc NULL 211 #endif 212 213 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) 214 { 215 return m41t80_get_datetime(to_i2c_client(dev), tm); 216 } 217 218 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) 219 { 220 return m41t80_set_datetime(to_i2c_client(dev), tm); 221 } 222 223 /* 224 * XXX - m41t80 alarm functionality is reported broken. 225 * until it is fixed, don't register alarm functions. 226 */ 227 static struct rtc_class_ops m41t80_rtc_ops = { 228 .read_time = m41t80_rtc_read_time, 229 .set_time = m41t80_rtc_set_time, 230 .proc = m41t80_rtc_proc, 231 }; 232 233 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) 234 static ssize_t m41t80_sysfs_show_flags(struct device *dev, 235 struct device_attribute *attr, char *buf) 236 { 237 struct i2c_client *client = to_i2c_client(dev); 238 int val; 239 240 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 241 if (val < 0) 242 return val; 243 return sprintf(buf, "%#x\n", val); 244 } 245 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); 246 247 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, 248 struct device_attribute *attr, char *buf) 249 { 250 struct i2c_client *client = to_i2c_client(dev); 251 struct m41t80_data *clientdata = i2c_get_clientdata(client); 252 int val, reg_sqw; 253 254 if (!(clientdata->features & M41T80_FEATURE_SQ)) 255 return -EINVAL; 256 257 reg_sqw = M41T80_REG_SQW; 258 if (clientdata->features & M41T80_FEATURE_SQ_ALT) 259 reg_sqw = M41T80_REG_WDAY; 260 val = i2c_smbus_read_byte_data(client, reg_sqw); 261 if (val < 0) 262 return val; 263 val = (val >> 4) & 0xf; 264 switch (val) { 265 case 0: 266 break; 267 case 1: 268 val = 32768; 269 break; 270 default: 271 val = 32768 >> val; 272 } 273 return sprintf(buf, "%d\n", val); 274 } 275 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev, 276 struct device_attribute *attr, 277 const char *buf, size_t count) 278 { 279 struct i2c_client *client = to_i2c_client(dev); 280 struct m41t80_data *clientdata = i2c_get_clientdata(client); 281 int almon, sqw, reg_sqw, rc; 282 int val = simple_strtoul(buf, NULL, 0); 283 284 if (!(clientdata->features & M41T80_FEATURE_SQ)) 285 return -EINVAL; 286 287 if (val) { 288 if (!is_power_of_2(val)) 289 return -EINVAL; 290 val = ilog2(val); 291 if (val == 15) 292 val = 1; 293 else if (val < 14) 294 val = 15 - val; 295 else 296 return -EINVAL; 297 } 298 /* disable SQW, set SQW frequency & re-enable */ 299 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 300 if (almon < 0) 301 return almon; 302 reg_sqw = M41T80_REG_SQW; 303 if (clientdata->features & M41T80_FEATURE_SQ_ALT) 304 reg_sqw = M41T80_REG_WDAY; 305 sqw = i2c_smbus_read_byte_data(client, reg_sqw); 306 if (sqw < 0) 307 return sqw; 308 sqw = (sqw & 0x0f) | (val << 4); 309 310 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 311 almon & ~M41T80_ALMON_SQWE); 312 if (rc < 0) 313 return rc; 314 315 if (val) { 316 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw); 317 if (rc < 0) 318 return rc; 319 320 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 321 almon | M41T80_ALMON_SQWE); 322 if (rc <0) 323 return rc; 324 } 325 return count; 326 } 327 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, 328 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); 329 330 static struct attribute *attrs[] = { 331 &dev_attr_flags.attr, 332 &dev_attr_sqwfreq.attr, 333 NULL, 334 }; 335 static struct attribute_group attr_group = { 336 .attrs = attrs, 337 }; 338 339 static int m41t80_sysfs_register(struct device *dev) 340 { 341 return sysfs_create_group(&dev->kobj, &attr_group); 342 } 343 #else 344 static int m41t80_sysfs_register(struct device *dev) 345 { 346 return 0; 347 } 348 #endif 349 350 #ifdef CONFIG_RTC_DRV_M41T80_WDT 351 /* 352 ***************************************************************************** 353 * 354 * Watchdog Driver 355 * 356 ***************************************************************************** 357 */ 358 static struct i2c_client *save_client; 359 360 /* Default margin */ 361 #define WD_TIMO 60 /* 1..31 seconds */ 362 363 static int wdt_margin = WD_TIMO; 364 module_param(wdt_margin, int, 0); 365 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); 366 367 static unsigned long wdt_is_open; 368 static int boot_flag; 369 370 /** 371 * wdt_ping: 372 * 373 * Reload counter one with the watchdog timeout. We don't bother reloading 374 * the cascade counter. 375 */ 376 static void wdt_ping(void) 377 { 378 unsigned char i2c_data[2]; 379 struct i2c_msg msgs1[1] = { 380 { 381 .addr = save_client->addr, 382 .flags = 0, 383 .len = 2, 384 .buf = i2c_data, 385 }, 386 }; 387 struct m41t80_data *clientdata = i2c_get_clientdata(save_client); 388 389 i2c_data[0] = 0x09; /* watchdog register */ 390 391 if (wdt_margin > 31) 392 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ 393 else 394 /* 395 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) 396 */ 397 i2c_data[1] = wdt_margin<<2 | 0x82; 398 399 /* 400 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as 401 * that would be an invalid resolution. 402 */ 403 if (clientdata->features & M41T80_FEATURE_WD) 404 i2c_data[1] &= ~M41T80_WATCHDOG_RB2; 405 406 i2c_transfer(save_client->adapter, msgs1, 1); 407 } 408 409 /** 410 * wdt_disable: 411 * 412 * disables watchdog. 413 */ 414 static void wdt_disable(void) 415 { 416 unsigned char i2c_data[2], i2c_buf[0x10]; 417 struct i2c_msg msgs0[2] = { 418 { 419 .addr = save_client->addr, 420 .flags = 0, 421 .len = 1, 422 .buf = i2c_data, 423 }, 424 { 425 .addr = save_client->addr, 426 .flags = I2C_M_RD, 427 .len = 1, 428 .buf = i2c_buf, 429 }, 430 }; 431 struct i2c_msg msgs1[1] = { 432 { 433 .addr = save_client->addr, 434 .flags = 0, 435 .len = 2, 436 .buf = i2c_data, 437 }, 438 }; 439 440 i2c_data[0] = 0x09; 441 i2c_transfer(save_client->adapter, msgs0, 2); 442 443 i2c_data[0] = 0x09; 444 i2c_data[1] = 0x00; 445 i2c_transfer(save_client->adapter, msgs1, 1); 446 } 447 448 /** 449 * wdt_write: 450 * @file: file handle to the watchdog 451 * @buf: buffer to write (unused as data does not matter here 452 * @count: count of bytes 453 * @ppos: pointer to the position to write. No seeks allowed 454 * 455 * A write to a watchdog device is defined as a keepalive signal. Any 456 * write of data will do, as we we don't define content meaning. 457 */ 458 static ssize_t wdt_write(struct file *file, const char __user *buf, 459 size_t count, loff_t *ppos) 460 { 461 if (count) { 462 wdt_ping(); 463 return 1; 464 } 465 return 0; 466 } 467 468 static ssize_t wdt_read(struct file *file, char __user *buf, 469 size_t count, loff_t *ppos) 470 { 471 return 0; 472 } 473 474 /** 475 * wdt_ioctl: 476 * @inode: inode of the device 477 * @file: file handle to the device 478 * @cmd: watchdog command 479 * @arg: argument pointer 480 * 481 * The watchdog API defines a common set of functions for all watchdogs 482 * according to their available features. We only actually usefully support 483 * querying capabilities and current status. 484 */ 485 static int wdt_ioctl(struct file *file, unsigned int cmd, 486 unsigned long arg) 487 { 488 int new_margin, rv; 489 static struct watchdog_info ident = { 490 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | 491 WDIOF_SETTIMEOUT, 492 .firmware_version = 1, 493 .identity = "M41T80 WTD" 494 }; 495 496 switch (cmd) { 497 case WDIOC_GETSUPPORT: 498 return copy_to_user((struct watchdog_info __user *)arg, &ident, 499 sizeof(ident)) ? -EFAULT : 0; 500 501 case WDIOC_GETSTATUS: 502 case WDIOC_GETBOOTSTATUS: 503 return put_user(boot_flag, (int __user *)arg); 504 case WDIOC_KEEPALIVE: 505 wdt_ping(); 506 return 0; 507 case WDIOC_SETTIMEOUT: 508 if (get_user(new_margin, (int __user *)arg)) 509 return -EFAULT; 510 /* Arbitrary, can't find the card's limits */ 511 if (new_margin < 1 || new_margin > 124) 512 return -EINVAL; 513 wdt_margin = new_margin; 514 wdt_ping(); 515 /* Fall */ 516 case WDIOC_GETTIMEOUT: 517 return put_user(wdt_margin, (int __user *)arg); 518 519 case WDIOC_SETOPTIONS: 520 if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) 521 return -EFAULT; 522 523 if (rv & WDIOS_DISABLECARD) { 524 pr_info("disable watchdog\n"); 525 wdt_disable(); 526 } 527 528 if (rv & WDIOS_ENABLECARD) { 529 pr_info("enable watchdog\n"); 530 wdt_ping(); 531 } 532 533 return -EINVAL; 534 } 535 return -ENOTTY; 536 } 537 538 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd, 539 unsigned long arg) 540 { 541 int ret; 542 543 mutex_lock(&m41t80_rtc_mutex); 544 ret = wdt_ioctl(file, cmd, arg); 545 mutex_unlock(&m41t80_rtc_mutex); 546 547 return ret; 548 } 549 550 /** 551 * wdt_open: 552 * @inode: inode of device 553 * @file: file handle to device 554 * 555 */ 556 static int wdt_open(struct inode *inode, struct file *file) 557 { 558 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { 559 mutex_lock(&m41t80_rtc_mutex); 560 if (test_and_set_bit(0, &wdt_is_open)) { 561 mutex_unlock(&m41t80_rtc_mutex); 562 return -EBUSY; 563 } 564 /* 565 * Activate 566 */ 567 wdt_is_open = 1; 568 mutex_unlock(&m41t80_rtc_mutex); 569 return nonseekable_open(inode, file); 570 } 571 return -ENODEV; 572 } 573 574 /** 575 * wdt_close: 576 * @inode: inode to board 577 * @file: file handle to board 578 * 579 */ 580 static int wdt_release(struct inode *inode, struct file *file) 581 { 582 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 583 clear_bit(0, &wdt_is_open); 584 return 0; 585 } 586 587 /** 588 * notify_sys: 589 * @this: our notifier block 590 * @code: the event being reported 591 * @unused: unused 592 * 593 * Our notifier is called on system shutdowns. We want to turn the card 594 * off at reboot otherwise the machine will reboot again during memory 595 * test or worse yet during the following fsck. This would suck, in fact 596 * trust me - if it happens it does suck. 597 */ 598 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 599 void *unused) 600 { 601 if (code == SYS_DOWN || code == SYS_HALT) 602 /* Disable Watchdog */ 603 wdt_disable(); 604 return NOTIFY_DONE; 605 } 606 607 static const struct file_operations wdt_fops = { 608 .owner = THIS_MODULE, 609 .read = wdt_read, 610 .unlocked_ioctl = wdt_unlocked_ioctl, 611 .write = wdt_write, 612 .open = wdt_open, 613 .release = wdt_release, 614 .llseek = no_llseek, 615 }; 616 617 static struct miscdevice wdt_dev = { 618 .minor = WATCHDOG_MINOR, 619 .name = "watchdog", 620 .fops = &wdt_fops, 621 }; 622 623 /* 624 * The WDT card needs to learn about soft shutdowns in order to 625 * turn the timebomb registers off. 626 */ 627 static struct notifier_block wdt_notifier = { 628 .notifier_call = wdt_notify_sys, 629 }; 630 #endif /* CONFIG_RTC_DRV_M41T80_WDT */ 631 632 /* 633 ***************************************************************************** 634 * 635 * Driver Interface 636 * 637 ***************************************************************************** 638 */ 639 static int m41t80_probe(struct i2c_client *client, 640 const struct i2c_device_id *id) 641 { 642 int rc = 0; 643 struct rtc_device *rtc = NULL; 644 struct rtc_time tm; 645 struct m41t80_data *clientdata = NULL; 646 647 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C 648 | I2C_FUNC_SMBUS_BYTE_DATA)) 649 return -ENODEV; 650 651 clientdata = devm_kzalloc(&client->dev, sizeof(*clientdata), 652 GFP_KERNEL); 653 if (!clientdata) 654 return -ENOMEM; 655 656 clientdata->features = id->driver_data; 657 i2c_set_clientdata(client, clientdata); 658 659 rtc = devm_rtc_device_register(&client->dev, client->name, 660 &m41t80_rtc_ops, THIS_MODULE); 661 if (IS_ERR(rtc)) 662 return PTR_ERR(rtc); 663 664 clientdata->rtc = rtc; 665 666 /* Make sure HT (Halt Update) bit is cleared */ 667 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); 668 669 if (rc >= 0 && rc & M41T80_ALHOUR_HT) { 670 if (clientdata->features & M41T80_FEATURE_HT) { 671 m41t80_get_datetime(client, &tm); 672 dev_info(&client->dev, "HT bit was set!\n"); 673 dev_info(&client->dev, 674 "Power Down at " 675 "%04i-%02i-%02i %02i:%02i:%02i\n", 676 tm.tm_year + 1900, 677 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 678 tm.tm_min, tm.tm_sec); 679 } 680 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR, 681 rc & ~M41T80_ALHOUR_HT); 682 } 683 684 if (rc < 0) { 685 dev_err(&client->dev, "Can't clear HT bit\n"); 686 return rc; 687 } 688 689 /* Make sure ST (stop) bit is cleared */ 690 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); 691 692 if (rc >= 0 && rc & M41T80_SEC_ST) 693 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, 694 rc & ~M41T80_SEC_ST); 695 if (rc < 0) { 696 dev_err(&client->dev, "Can't clear ST bit\n"); 697 return rc; 698 } 699 700 rc = m41t80_sysfs_register(&client->dev); 701 if (rc) 702 return rc; 703 704 #ifdef CONFIG_RTC_DRV_M41T80_WDT 705 if (clientdata->features & M41T80_FEATURE_HT) { 706 save_client = client; 707 rc = misc_register(&wdt_dev); 708 if (rc) 709 return rc; 710 rc = register_reboot_notifier(&wdt_notifier); 711 if (rc) { 712 misc_deregister(&wdt_dev); 713 return rc; 714 } 715 } 716 #endif 717 return 0; 718 } 719 720 static int m41t80_remove(struct i2c_client *client) 721 { 722 #ifdef CONFIG_RTC_DRV_M41T80_WDT 723 struct m41t80_data *clientdata = i2c_get_clientdata(client); 724 725 if (clientdata->features & M41T80_FEATURE_HT) { 726 misc_deregister(&wdt_dev); 727 unregister_reboot_notifier(&wdt_notifier); 728 } 729 #endif 730 731 return 0; 732 } 733 734 static struct i2c_driver m41t80_driver = { 735 .driver = { 736 .name = "rtc-m41t80", 737 }, 738 .probe = m41t80_probe, 739 .remove = m41t80_remove, 740 .id_table = m41t80_id, 741 }; 742 743 module_i2c_driver(m41t80_driver); 744 745 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); 746 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); 747 MODULE_LICENSE("GPL"); 748