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 0x00 36 #define M41T80_REG_SEC 0x01 37 #define M41T80_REG_MIN 0x02 38 #define M41T80_REG_HOUR 0x03 39 #define M41T80_REG_WDAY 0x04 40 #define M41T80_REG_DAY 0x05 41 #define M41T80_REG_MON 0x06 42 #define M41T80_REG_YEAR 0x07 43 #define M41T80_REG_ALARM_MON 0x0a 44 #define M41T80_REG_ALARM_DAY 0x0b 45 #define M41T80_REG_ALARM_HOUR 0x0c 46 #define M41T80_REG_ALARM_MIN 0x0d 47 #define M41T80_REG_ALARM_SEC 0x0e 48 #define M41T80_REG_FLAGS 0x0f 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 BIT(7) /* ST: Stop Bit */ 56 #define M41T80_ALMON_AFE BIT(7) /* AFE: AF Enable Bit */ 57 #define M41T80_ALMON_SQWE BIT(6) /* SQWE: SQW Enable Bit */ 58 #define M41T80_ALHOUR_HT BIT(6) /* HT: Halt Update Bit */ 59 #define M41T80_FLAGS_OF BIT(2) /* OF: Oscillator Failure Bit */ 60 #define M41T80_FLAGS_AF BIT(6) /* AF: Alarm Flag Bit */ 61 #define M41T80_FLAGS_BATT_LOW BIT(4) /* BL: Battery Low Bit */ 62 #define M41T80_WATCHDOG_RB2 BIT(7) /* RB: Watchdog resolution */ 63 #define M41T80_WATCHDOG_RB1 BIT(1) /* RB: Watchdog resolution */ 64 #define M41T80_WATCHDOG_RB0 BIT(0) /* RB: Watchdog resolution */ 65 66 #define M41T80_FEATURE_HT BIT(0) /* Halt feature */ 67 #define M41T80_FEATURE_BL BIT(1) /* Battery low indicator */ 68 #define M41T80_FEATURE_SQ BIT(2) /* Squarewave feature */ 69 #define M41T80_FEATURE_WD BIT(3) /* Extra watchdog resolution */ 70 #define M41T80_FEATURE_SQ_ALT BIT(4) /* RSx bits are in reg 4 */ 71 72 static DEFINE_MUTEX(m41t80_rtc_mutex); 73 static const struct i2c_device_id m41t80_id[] = { 74 { "m41t62", M41T80_FEATURE_SQ | M41T80_FEATURE_SQ_ALT }, 75 { "m41t65", M41T80_FEATURE_HT | M41T80_FEATURE_WD }, 76 { "m41t80", M41T80_FEATURE_SQ }, 77 { "m41t81", M41T80_FEATURE_HT | M41T80_FEATURE_SQ}, 78 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 79 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 80 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 81 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 82 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 83 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL | M41T80_FEATURE_SQ }, 84 { "rv4162", M41T80_FEATURE_SQ | M41T80_FEATURE_WD | M41T80_FEATURE_SQ_ALT }, 85 { } 86 }; 87 MODULE_DEVICE_TABLE(i2c, m41t80_id); 88 89 struct m41t80_data { 90 u8 features; 91 struct rtc_device *rtc; 92 }; 93 94 static irqreturn_t m41t80_handle_irq(int irq, void *dev_id) 95 { 96 struct i2c_client *client = dev_id; 97 struct m41t80_data *m41t80 = i2c_get_clientdata(client); 98 struct mutex *lock = &m41t80->rtc->ops_lock; 99 unsigned long events = 0; 100 int flags, flags_afe; 101 102 mutex_lock(lock); 103 104 flags_afe = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 105 if (flags_afe < 0) { 106 mutex_unlock(lock); 107 return IRQ_NONE; 108 } 109 110 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 111 if (flags <= 0) { 112 mutex_unlock(lock); 113 return IRQ_NONE; 114 } 115 116 if (flags & M41T80_FLAGS_AF) { 117 flags &= ~M41T80_FLAGS_AF; 118 flags_afe &= ~M41T80_ALMON_AFE; 119 events |= RTC_AF; 120 } 121 122 if (events) { 123 rtc_update_irq(m41t80->rtc, 1, events); 124 i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, flags); 125 i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 126 flags_afe); 127 } 128 129 mutex_unlock(lock); 130 131 return IRQ_HANDLED; 132 } 133 134 static int m41t80_get_datetime(struct i2c_client *client, 135 struct rtc_time *tm) 136 { 137 unsigned char buf[8]; 138 int err, flags; 139 140 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 141 if (flags < 0) 142 return flags; 143 144 if (flags & M41T80_FLAGS_OF) { 145 dev_err(&client->dev, "Oscillator failure, data is invalid.\n"); 146 return -EINVAL; 147 } 148 149 err = i2c_smbus_read_i2c_block_data(client, M41T80_REG_SSEC, 150 sizeof(buf), buf); 151 if (err < 0) { 152 dev_err(&client->dev, "Unable to read date\n"); 153 return -EIO; 154 } 155 156 tm->tm_sec = bcd2bin(buf[M41T80_REG_SEC] & 0x7f); 157 tm->tm_min = bcd2bin(buf[M41T80_REG_MIN] & 0x7f); 158 tm->tm_hour = bcd2bin(buf[M41T80_REG_HOUR] & 0x3f); 159 tm->tm_mday = bcd2bin(buf[M41T80_REG_DAY] & 0x3f); 160 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; 161 tm->tm_mon = bcd2bin(buf[M41T80_REG_MON] & 0x1f) - 1; 162 163 /* assume 20YY not 19YY, and ignore the Century Bit */ 164 tm->tm_year = bcd2bin(buf[M41T80_REG_YEAR]) + 100; 165 return rtc_valid_tm(tm); 166 } 167 168 /* Sets the given date and time to the real time clock. */ 169 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) 170 { 171 unsigned char buf[8]; 172 int err, flags; 173 174 if (tm->tm_year < 100 || tm->tm_year > 199) 175 return -EINVAL; 176 177 buf[M41T80_REG_SSEC] = 0; 178 buf[M41T80_REG_SEC] = bin2bcd(tm->tm_sec); 179 buf[M41T80_REG_MIN] = bin2bcd(tm->tm_min); 180 buf[M41T80_REG_HOUR] = bin2bcd(tm->tm_hour); 181 buf[M41T80_REG_DAY] = bin2bcd(tm->tm_mday); 182 buf[M41T80_REG_MON] = bin2bcd(tm->tm_mon + 1); 183 buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year - 100); 184 buf[M41T80_REG_WDAY] = tm->tm_wday; 185 186 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_SSEC, 187 sizeof(buf), buf); 188 if (err < 0) { 189 dev_err(&client->dev, "Unable to write to date registers\n"); 190 return err; 191 } 192 193 /* Clear the OF bit of Flags Register */ 194 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 195 if (flags < 0) 196 return flags; 197 198 if (i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, 199 flags & ~M41T80_FLAGS_OF)) { 200 dev_err(&client->dev, "Unable to write flags register\n"); 201 return -EIO; 202 } 203 204 return err; 205 } 206 207 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) 208 { 209 struct i2c_client *client = to_i2c_client(dev); 210 struct m41t80_data *clientdata = i2c_get_clientdata(client); 211 u8 reg; 212 213 if (clientdata->features & M41T80_FEATURE_BL) { 214 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 215 seq_printf(seq, "battery\t\t: %s\n", 216 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); 217 } 218 return 0; 219 } 220 221 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) 222 { 223 return m41t80_get_datetime(to_i2c_client(dev), tm); 224 } 225 226 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) 227 { 228 return m41t80_set_datetime(to_i2c_client(dev), tm); 229 } 230 231 static int m41t80_alarm_irq_enable(struct device *dev, unsigned int enabled) 232 { 233 struct i2c_client *client = to_i2c_client(dev); 234 int flags, retval; 235 236 flags = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 237 if (flags < 0) 238 return flags; 239 240 if (enabled) 241 flags |= M41T80_ALMON_AFE; 242 else 243 flags &= ~M41T80_ALMON_AFE; 244 245 retval = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, flags); 246 if (retval < 0) { 247 dev_err(dev, "Unable to enable alarm IRQ %d\n", retval); 248 return retval; 249 } 250 return 0; 251 } 252 253 static int m41t80_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 254 { 255 struct i2c_client *client = to_i2c_client(dev); 256 u8 alarmvals[5]; 257 int ret, err; 258 259 alarmvals[0] = bin2bcd(alrm->time.tm_mon + 1); 260 alarmvals[1] = bin2bcd(alrm->time.tm_mday); 261 alarmvals[2] = bin2bcd(alrm->time.tm_hour); 262 alarmvals[3] = bin2bcd(alrm->time.tm_min); 263 alarmvals[4] = bin2bcd(alrm->time.tm_sec); 264 265 /* Clear AF and AFE flags */ 266 ret = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 267 if (ret < 0) 268 return ret; 269 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 270 ret & ~(M41T80_ALMON_AFE)); 271 if (err < 0) { 272 dev_err(dev, "Unable to clear AFE bit\n"); 273 return err; 274 } 275 276 ret = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 277 if (ret < 0) 278 return ret; 279 280 err = i2c_smbus_write_byte_data(client, M41T80_REG_FLAGS, 281 ret & ~(M41T80_FLAGS_AF)); 282 if (err < 0) { 283 dev_err(dev, "Unable to clear AF bit\n"); 284 return err; 285 } 286 287 /* Write the alarm */ 288 err = i2c_smbus_write_i2c_block_data(client, M41T80_REG_ALARM_MON, 289 5, alarmvals); 290 if (err) 291 return err; 292 293 /* Enable the alarm interrupt */ 294 if (alrm->enabled) { 295 alarmvals[0] |= M41T80_ALMON_AFE; 296 err = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 297 alarmvals[0]); 298 if (err) 299 return err; 300 } 301 302 return 0; 303 } 304 305 static int m41t80_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 306 { 307 struct i2c_client *client = to_i2c_client(dev); 308 u8 alarmvals[5]; 309 int flags, ret; 310 311 ret = i2c_smbus_read_i2c_block_data(client, M41T80_REG_ALARM_MON, 312 5, alarmvals); 313 if (ret != 5) 314 return ret < 0 ? ret : -EIO; 315 316 flags = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 317 if (flags < 0) 318 return flags; 319 320 alrm->time.tm_sec = bcd2bin(alarmvals[4] & 0x7f); 321 alrm->time.tm_min = bcd2bin(alarmvals[3] & 0x7f); 322 alrm->time.tm_hour = bcd2bin(alarmvals[2] & 0x3f); 323 alrm->time.tm_mday = bcd2bin(alarmvals[1] & 0x3f); 324 alrm->time.tm_mon = bcd2bin(alarmvals[0] & 0x3f); 325 326 alrm->enabled = !!(alarmvals[0] & M41T80_ALMON_AFE); 327 alrm->pending = (flags & M41T80_FLAGS_AF) && alrm->enabled; 328 329 return 0; 330 } 331 332 static struct rtc_class_ops m41t80_rtc_ops = { 333 .read_time = m41t80_rtc_read_time, 334 .set_time = m41t80_rtc_set_time, 335 .proc = m41t80_rtc_proc, 336 }; 337 338 #ifdef CONFIG_PM_SLEEP 339 static int m41t80_suspend(struct device *dev) 340 { 341 struct i2c_client *client = to_i2c_client(dev); 342 343 if (client->irq >= 0 && device_may_wakeup(dev)) 344 enable_irq_wake(client->irq); 345 346 return 0; 347 } 348 349 static int m41t80_resume(struct device *dev) 350 { 351 struct i2c_client *client = to_i2c_client(dev); 352 353 if (client->irq >= 0 && device_may_wakeup(dev)) 354 disable_irq_wake(client->irq); 355 356 return 0; 357 } 358 #endif 359 360 static SIMPLE_DEV_PM_OPS(m41t80_pm, m41t80_suspend, m41t80_resume); 361 362 static ssize_t flags_show(struct device *dev, 363 struct device_attribute *attr, char *buf) 364 { 365 struct i2c_client *client = to_i2c_client(dev); 366 int val; 367 368 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 369 if (val < 0) 370 return val; 371 return sprintf(buf, "%#x\n", val); 372 } 373 static DEVICE_ATTR_RO(flags); 374 375 static ssize_t sqwfreq_show(struct device *dev, 376 struct device_attribute *attr, char *buf) 377 { 378 struct i2c_client *client = to_i2c_client(dev); 379 struct m41t80_data *clientdata = i2c_get_clientdata(client); 380 int val, reg_sqw; 381 382 if (!(clientdata->features & M41T80_FEATURE_SQ)) 383 return -EINVAL; 384 385 reg_sqw = M41T80_REG_SQW; 386 if (clientdata->features & M41T80_FEATURE_SQ_ALT) 387 reg_sqw = M41T80_REG_WDAY; 388 val = i2c_smbus_read_byte_data(client, reg_sqw); 389 if (val < 0) 390 return val; 391 val = (val >> 4) & 0xf; 392 switch (val) { 393 case 0: 394 break; 395 case 1: 396 val = 32768; 397 break; 398 default: 399 val = 32768 >> val; 400 } 401 return sprintf(buf, "%d\n", val); 402 } 403 404 static ssize_t sqwfreq_store(struct device *dev, 405 struct device_attribute *attr, 406 const char *buf, size_t count) 407 { 408 struct i2c_client *client = to_i2c_client(dev); 409 struct m41t80_data *clientdata = i2c_get_clientdata(client); 410 int almon, sqw, reg_sqw, rc; 411 unsigned long val; 412 413 rc = kstrtoul(buf, 0, &val); 414 if (rc < 0) 415 return rc; 416 417 if (!(clientdata->features & M41T80_FEATURE_SQ)) 418 return -EINVAL; 419 420 if (val) { 421 if (!is_power_of_2(val)) 422 return -EINVAL; 423 val = ilog2(val); 424 if (val == 15) 425 val = 1; 426 else if (val < 14) 427 val = 15 - val; 428 else 429 return -EINVAL; 430 } 431 /* disable SQW, set SQW frequency & re-enable */ 432 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 433 if (almon < 0) 434 return almon; 435 reg_sqw = M41T80_REG_SQW; 436 if (clientdata->features & M41T80_FEATURE_SQ_ALT) 437 reg_sqw = M41T80_REG_WDAY; 438 sqw = i2c_smbus_read_byte_data(client, reg_sqw); 439 if (sqw < 0) 440 return sqw; 441 sqw = (sqw & 0x0f) | (val << 4); 442 443 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 444 almon & ~M41T80_ALMON_SQWE); 445 if (rc < 0) 446 return rc; 447 448 if (val) { 449 rc = i2c_smbus_write_byte_data(client, reg_sqw, sqw); 450 if (rc < 0) 451 return rc; 452 453 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 454 almon | M41T80_ALMON_SQWE); 455 if (rc < 0) 456 return rc; 457 } 458 return count; 459 } 460 static DEVICE_ATTR_RW(sqwfreq); 461 462 static struct attribute *attrs[] = { 463 &dev_attr_flags.attr, 464 &dev_attr_sqwfreq.attr, 465 NULL, 466 }; 467 468 static struct attribute_group attr_group = { 469 .attrs = attrs, 470 }; 471 472 #ifdef CONFIG_RTC_DRV_M41T80_WDT 473 /* 474 ***************************************************************************** 475 * 476 * Watchdog Driver 477 * 478 ***************************************************************************** 479 */ 480 static struct i2c_client *save_client; 481 482 /* Default margin */ 483 #define WD_TIMO 60 /* 1..31 seconds */ 484 485 static int wdt_margin = WD_TIMO; 486 module_param(wdt_margin, int, 0); 487 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); 488 489 static unsigned long wdt_is_open; 490 static int boot_flag; 491 492 /** 493 * wdt_ping: 494 * 495 * Reload counter one with the watchdog timeout. We don't bother reloading 496 * the cascade counter. 497 */ 498 static void wdt_ping(void) 499 { 500 unsigned char i2c_data[2]; 501 struct i2c_msg msgs1[1] = { 502 { 503 .addr = save_client->addr, 504 .flags = 0, 505 .len = 2, 506 .buf = i2c_data, 507 }, 508 }; 509 struct m41t80_data *clientdata = i2c_get_clientdata(save_client); 510 511 i2c_data[0] = 0x09; /* watchdog register */ 512 513 if (wdt_margin > 31) 514 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ 515 else 516 /* 517 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) 518 */ 519 i2c_data[1] = wdt_margin << 2 | 0x82; 520 521 /* 522 * M41T65 has three bits for watchdog resolution. Don't set bit 7, as 523 * that would be an invalid resolution. 524 */ 525 if (clientdata->features & M41T80_FEATURE_WD) 526 i2c_data[1] &= ~M41T80_WATCHDOG_RB2; 527 528 i2c_transfer(save_client->adapter, msgs1, 1); 529 } 530 531 /** 532 * wdt_disable: 533 * 534 * disables watchdog. 535 */ 536 static void wdt_disable(void) 537 { 538 unsigned char i2c_data[2], i2c_buf[0x10]; 539 struct i2c_msg msgs0[2] = { 540 { 541 .addr = save_client->addr, 542 .flags = 0, 543 .len = 1, 544 .buf = i2c_data, 545 }, 546 { 547 .addr = save_client->addr, 548 .flags = I2C_M_RD, 549 .len = 1, 550 .buf = i2c_buf, 551 }, 552 }; 553 struct i2c_msg msgs1[1] = { 554 { 555 .addr = save_client->addr, 556 .flags = 0, 557 .len = 2, 558 .buf = i2c_data, 559 }, 560 }; 561 562 i2c_data[0] = 0x09; 563 i2c_transfer(save_client->adapter, msgs0, 2); 564 565 i2c_data[0] = 0x09; 566 i2c_data[1] = 0x00; 567 i2c_transfer(save_client->adapter, msgs1, 1); 568 } 569 570 /** 571 * wdt_write: 572 * @file: file handle to the watchdog 573 * @buf: buffer to write (unused as data does not matter here 574 * @count: count of bytes 575 * @ppos: pointer to the position to write. No seeks allowed 576 * 577 * A write to a watchdog device is defined as a keepalive signal. Any 578 * write of data will do, as we we don't define content meaning. 579 */ 580 static ssize_t wdt_write(struct file *file, const char __user *buf, 581 size_t count, loff_t *ppos) 582 { 583 if (count) { 584 wdt_ping(); 585 return 1; 586 } 587 return 0; 588 } 589 590 static ssize_t wdt_read(struct file *file, char __user *buf, 591 size_t count, loff_t *ppos) 592 { 593 return 0; 594 } 595 596 /** 597 * wdt_ioctl: 598 * @inode: inode of the device 599 * @file: file handle to the device 600 * @cmd: watchdog command 601 * @arg: argument pointer 602 * 603 * The watchdog API defines a common set of functions for all watchdogs 604 * according to their available features. We only actually usefully support 605 * querying capabilities and current status. 606 */ 607 static int wdt_ioctl(struct file *file, unsigned int cmd, 608 unsigned long arg) 609 { 610 int new_margin, rv; 611 static struct watchdog_info ident = { 612 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | 613 WDIOF_SETTIMEOUT, 614 .firmware_version = 1, 615 .identity = "M41T80 WTD" 616 }; 617 618 switch (cmd) { 619 case WDIOC_GETSUPPORT: 620 return copy_to_user((struct watchdog_info __user *)arg, &ident, 621 sizeof(ident)) ? -EFAULT : 0; 622 623 case WDIOC_GETSTATUS: 624 case WDIOC_GETBOOTSTATUS: 625 return put_user(boot_flag, (int __user *)arg); 626 case WDIOC_KEEPALIVE: 627 wdt_ping(); 628 return 0; 629 case WDIOC_SETTIMEOUT: 630 if (get_user(new_margin, (int __user *)arg)) 631 return -EFAULT; 632 /* Arbitrary, can't find the card's limits */ 633 if (new_margin < 1 || new_margin > 124) 634 return -EINVAL; 635 wdt_margin = new_margin; 636 wdt_ping(); 637 /* Fall */ 638 case WDIOC_GETTIMEOUT: 639 return put_user(wdt_margin, (int __user *)arg); 640 641 case WDIOC_SETOPTIONS: 642 if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) 643 return -EFAULT; 644 645 if (rv & WDIOS_DISABLECARD) { 646 pr_info("disable watchdog\n"); 647 wdt_disable(); 648 } 649 650 if (rv & WDIOS_ENABLECARD) { 651 pr_info("enable watchdog\n"); 652 wdt_ping(); 653 } 654 655 return -EINVAL; 656 } 657 return -ENOTTY; 658 } 659 660 static long wdt_unlocked_ioctl(struct file *file, unsigned int cmd, 661 unsigned long arg) 662 { 663 int ret; 664 665 mutex_lock(&m41t80_rtc_mutex); 666 ret = wdt_ioctl(file, cmd, arg); 667 mutex_unlock(&m41t80_rtc_mutex); 668 669 return ret; 670 } 671 672 /** 673 * wdt_open: 674 * @inode: inode of device 675 * @file: file handle to device 676 * 677 */ 678 static int wdt_open(struct inode *inode, struct file *file) 679 { 680 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { 681 mutex_lock(&m41t80_rtc_mutex); 682 if (test_and_set_bit(0, &wdt_is_open)) { 683 mutex_unlock(&m41t80_rtc_mutex); 684 return -EBUSY; 685 } 686 /* 687 * Activate 688 */ 689 wdt_is_open = 1; 690 mutex_unlock(&m41t80_rtc_mutex); 691 return nonseekable_open(inode, file); 692 } 693 return -ENODEV; 694 } 695 696 /** 697 * wdt_close: 698 * @inode: inode to board 699 * @file: file handle to board 700 * 701 */ 702 static int wdt_release(struct inode *inode, struct file *file) 703 { 704 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 705 clear_bit(0, &wdt_is_open); 706 return 0; 707 } 708 709 /** 710 * notify_sys: 711 * @this: our notifier block 712 * @code: the event being reported 713 * @unused: unused 714 * 715 * Our notifier is called on system shutdowns. We want to turn the card 716 * off at reboot otherwise the machine will reboot again during memory 717 * test or worse yet during the following fsck. This would suck, in fact 718 * trust me - if it happens it does suck. 719 */ 720 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 721 void *unused) 722 { 723 if (code == SYS_DOWN || code == SYS_HALT) 724 /* Disable Watchdog */ 725 wdt_disable(); 726 return NOTIFY_DONE; 727 } 728 729 static const struct file_operations wdt_fops = { 730 .owner = THIS_MODULE, 731 .read = wdt_read, 732 .unlocked_ioctl = wdt_unlocked_ioctl, 733 .write = wdt_write, 734 .open = wdt_open, 735 .release = wdt_release, 736 .llseek = no_llseek, 737 }; 738 739 static struct miscdevice wdt_dev = { 740 .minor = WATCHDOG_MINOR, 741 .name = "watchdog", 742 .fops = &wdt_fops, 743 }; 744 745 /* 746 * The WDT card needs to learn about soft shutdowns in order to 747 * turn the timebomb registers off. 748 */ 749 static struct notifier_block wdt_notifier = { 750 .notifier_call = wdt_notify_sys, 751 }; 752 #endif /* CONFIG_RTC_DRV_M41T80_WDT */ 753 754 /* 755 ***************************************************************************** 756 * 757 * Driver Interface 758 * 759 ***************************************************************************** 760 */ 761 762 static void m41t80_remove_sysfs_group(void *_dev) 763 { 764 struct device *dev = _dev; 765 766 sysfs_remove_group(&dev->kobj, &attr_group); 767 } 768 769 static int m41t80_probe(struct i2c_client *client, 770 const struct i2c_device_id *id) 771 { 772 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 773 int rc = 0; 774 struct rtc_device *rtc = NULL; 775 struct rtc_time tm; 776 struct m41t80_data *m41t80_data = NULL; 777 778 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK | 779 I2C_FUNC_SMBUS_BYTE_DATA)) { 780 dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); 781 return -ENODEV; 782 } 783 784 m41t80_data = devm_kzalloc(&client->dev, sizeof(*m41t80_data), 785 GFP_KERNEL); 786 if (!m41t80_data) 787 return -ENOMEM; 788 789 m41t80_data->features = id->driver_data; 790 i2c_set_clientdata(client, m41t80_data); 791 792 if (client->irq > 0) { 793 rc = devm_request_threaded_irq(&client->dev, client->irq, 794 NULL, m41t80_handle_irq, 795 IRQF_TRIGGER_LOW | IRQF_ONESHOT, 796 "m41t80", client); 797 if (rc) { 798 dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); 799 client->irq = 0; 800 } else { 801 m41t80_rtc_ops.read_alarm = m41t80_read_alarm; 802 m41t80_rtc_ops.set_alarm = m41t80_set_alarm; 803 m41t80_rtc_ops.alarm_irq_enable = m41t80_alarm_irq_enable; 804 /* Enable the wakealarm */ 805 device_init_wakeup(&client->dev, true); 806 } 807 } 808 809 rtc = devm_rtc_device_register(&client->dev, client->name, 810 &m41t80_rtc_ops, THIS_MODULE); 811 if (IS_ERR(rtc)) 812 return PTR_ERR(rtc); 813 814 m41t80_data->rtc = rtc; 815 816 /* Make sure HT (Halt Update) bit is cleared */ 817 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); 818 819 if (rc >= 0 && rc & M41T80_ALHOUR_HT) { 820 if (m41t80_data->features & M41T80_FEATURE_HT) { 821 m41t80_get_datetime(client, &tm); 822 dev_info(&client->dev, "HT bit was set!\n"); 823 dev_info(&client->dev, 824 "Power Down at %04i-%02i-%02i %02i:%02i:%02i\n", 825 tm.tm_year + 1900, 826 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 827 tm.tm_min, tm.tm_sec); 828 } 829 rc = i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_HOUR, 830 rc & ~M41T80_ALHOUR_HT); 831 } 832 833 if (rc < 0) { 834 dev_err(&client->dev, "Can't clear HT bit\n"); 835 return rc; 836 } 837 838 /* Make sure ST (stop) bit is cleared */ 839 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); 840 841 if (rc >= 0 && rc & M41T80_SEC_ST) 842 rc = i2c_smbus_write_byte_data(client, M41T80_REG_SEC, 843 rc & ~M41T80_SEC_ST); 844 if (rc < 0) { 845 dev_err(&client->dev, "Can't clear ST bit\n"); 846 return rc; 847 } 848 849 /* Export sysfs entries */ 850 rc = sysfs_create_group(&(&client->dev)->kobj, &attr_group); 851 if (rc) { 852 dev_err(&client->dev, "Failed to create sysfs group: %d\n", rc); 853 return rc; 854 } 855 856 rc = devm_add_action_or_reset(&client->dev, m41t80_remove_sysfs_group, 857 &client->dev); 858 if (rc) { 859 dev_err(&client->dev, 860 "Failed to add sysfs cleanup action: %d\n", rc); 861 return rc; 862 } 863 864 #ifdef CONFIG_RTC_DRV_M41T80_WDT 865 if (m41t80_data->features & M41T80_FEATURE_HT) { 866 save_client = client; 867 rc = misc_register(&wdt_dev); 868 if (rc) 869 return rc; 870 rc = register_reboot_notifier(&wdt_notifier); 871 if (rc) { 872 misc_deregister(&wdt_dev); 873 return rc; 874 } 875 } 876 #endif 877 return 0; 878 } 879 880 static int m41t80_remove(struct i2c_client *client) 881 { 882 #ifdef CONFIG_RTC_DRV_M41T80_WDT 883 struct m41t80_data *clientdata = i2c_get_clientdata(client); 884 885 if (clientdata->features & M41T80_FEATURE_HT) { 886 misc_deregister(&wdt_dev); 887 unregister_reboot_notifier(&wdt_notifier); 888 } 889 #endif 890 891 return 0; 892 } 893 894 static struct i2c_driver m41t80_driver = { 895 .driver = { 896 .name = "rtc-m41t80", 897 .pm = &m41t80_pm, 898 }, 899 .probe = m41t80_probe, 900 .remove = m41t80_remove, 901 .id_table = m41t80_id, 902 }; 903 904 module_i2c_driver(m41t80_driver); 905 906 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); 907 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); 908 MODULE_LICENSE("GPL"); 909