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 #include <linux/module.h> 17 #include <linux/init.h> 18 #include <linux/slab.h> 19 #include <linux/string.h> 20 #include <linux/i2c.h> 21 #include <linux/rtc.h> 22 #include <linux/bcd.h> 23 #ifdef CONFIG_RTC_DRV_M41T80_WDT 24 #include <linux/miscdevice.h> 25 #include <linux/watchdog.h> 26 #include <linux/reboot.h> 27 #include <linux/fs.h> 28 #include <linux/ioctl.h> 29 #endif 30 31 #define M41T80_REG_SSEC 0 32 #define M41T80_REG_SEC 1 33 #define M41T80_REG_MIN 2 34 #define M41T80_REG_HOUR 3 35 #define M41T80_REG_WDAY 4 36 #define M41T80_REG_DAY 5 37 #define M41T80_REG_MON 6 38 #define M41T80_REG_YEAR 7 39 #define M41T80_REG_ALARM_MON 0xa 40 #define M41T80_REG_ALARM_DAY 0xb 41 #define M41T80_REG_ALARM_HOUR 0xc 42 #define M41T80_REG_ALARM_MIN 0xd 43 #define M41T80_REG_ALARM_SEC 0xe 44 #define M41T80_REG_FLAGS 0xf 45 #define M41T80_REG_SQW 0x13 46 47 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) 48 #define M41T80_ALARM_REG_SIZE \ 49 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) 50 51 #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */ 52 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ 53 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ 54 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ 55 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ 56 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ 57 58 #define M41T80_FEATURE_HT (1 << 0) 59 #define M41T80_FEATURE_BL (1 << 1) 60 61 #define DRV_VERSION "0.05" 62 63 struct m41t80_chip_info { 64 const char *name; 65 u8 features; 66 }; 67 68 static const struct m41t80_chip_info m41t80_chip_info_tbl[] = { 69 { 70 .name = "m41t80", 71 .features = 0, 72 }, 73 { 74 .name = "m41t81", 75 .features = M41T80_FEATURE_HT, 76 }, 77 { 78 .name = "m41t81s", 79 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 80 }, 81 { 82 .name = "m41t82", 83 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 84 }, 85 { 86 .name = "m41t83", 87 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 88 }, 89 { 90 .name = "m41st84", 91 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 92 }, 93 { 94 .name = "m41st85", 95 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 96 }, 97 { 98 .name = "m41st87", 99 .features = M41T80_FEATURE_HT | M41T80_FEATURE_BL, 100 }, 101 }; 102 103 struct m41t80_data { 104 const struct m41t80_chip_info *chip; 105 struct rtc_device *rtc; 106 }; 107 108 static int m41t80_get_datetime(struct i2c_client *client, 109 struct rtc_time *tm) 110 { 111 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; 112 struct i2c_msg msgs[] = { 113 { 114 .addr = client->addr, 115 .flags = 0, 116 .len = 1, 117 .buf = dt_addr, 118 }, 119 { 120 .addr = client->addr, 121 .flags = I2C_M_RD, 122 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 123 .buf = buf + M41T80_REG_SEC, 124 }, 125 }; 126 127 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 128 dev_err(&client->dev, "read error\n"); 129 return -EIO; 130 } 131 132 tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f); 133 tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f); 134 tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f); 135 tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f); 136 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; 137 tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1; 138 139 /* assume 20YY not 19YY, and ignore the Century Bit */ 140 tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100; 141 return 0; 142 } 143 144 /* Sets the given date and time to the real time clock. */ 145 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) 146 { 147 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; 148 u8 *buf = &wbuf[1]; 149 u8 dt_addr[1] = { M41T80_REG_SEC }; 150 struct i2c_msg msgs_in[] = { 151 { 152 .addr = client->addr, 153 .flags = 0, 154 .len = 1, 155 .buf = dt_addr, 156 }, 157 { 158 .addr = client->addr, 159 .flags = I2C_M_RD, 160 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 161 .buf = buf + M41T80_REG_SEC, 162 }, 163 }; 164 struct i2c_msg msgs[] = { 165 { 166 .addr = client->addr, 167 .flags = 0, 168 .len = 1 + M41T80_DATETIME_REG_SIZE, 169 .buf = wbuf, 170 }, 171 }; 172 173 /* Read current reg values into buf[1..7] */ 174 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 175 dev_err(&client->dev, "read error\n"); 176 return -EIO; 177 } 178 179 wbuf[0] = 0; /* offset into rtc's regs */ 180 /* Merge time-data and register flags into buf[0..7] */ 181 buf[M41T80_REG_SSEC] = 0; 182 buf[M41T80_REG_SEC] = 183 BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); 184 buf[M41T80_REG_MIN] = 185 BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); 186 buf[M41T80_REG_HOUR] = 187 BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ; 188 buf[M41T80_REG_WDAY] = 189 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); 190 buf[M41T80_REG_DAY] = 191 BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); 192 buf[M41T80_REG_MON] = 193 BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); 194 /* assume 20YY not 19YY */ 195 buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100); 196 197 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 198 dev_err(&client->dev, "write error\n"); 199 return -EIO; 200 } 201 return 0; 202 } 203 204 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) 205 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) 206 { 207 struct i2c_client *client = to_i2c_client(dev); 208 struct m41t80_data *clientdata = i2c_get_clientdata(client); 209 u8 reg; 210 211 if (clientdata->chip->features & M41T80_FEATURE_BL) { 212 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 213 seq_printf(seq, "battery\t\t: %s\n", 214 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); 215 } 216 return 0; 217 } 218 #else 219 #define m41t80_rtc_proc NULL 220 #endif 221 222 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) 223 { 224 return m41t80_get_datetime(to_i2c_client(dev), tm); 225 } 226 227 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) 228 { 229 return m41t80_set_datetime(to_i2c_client(dev), tm); 230 } 231 232 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) 233 static int 234 m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 235 { 236 struct i2c_client *client = to_i2c_client(dev); 237 int rc; 238 239 switch (cmd) { 240 case RTC_AIE_OFF: 241 case RTC_AIE_ON: 242 break; 243 default: 244 return -ENOIOCTLCMD; 245 } 246 247 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 248 if (rc < 0) 249 goto err; 250 switch (cmd) { 251 case RTC_AIE_OFF: 252 rc &= ~M41T80_ALMON_AFE; 253 break; 254 case RTC_AIE_ON: 255 rc |= M41T80_ALMON_AFE; 256 break; 257 } 258 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0) 259 goto err; 260 return 0; 261 err: 262 return -EIO; 263 } 264 #else 265 #define m41t80_rtc_ioctl NULL 266 #endif 267 268 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t) 269 { 270 struct i2c_client *client = to_i2c_client(dev); 271 u8 wbuf[1 + M41T80_ALARM_REG_SIZE]; 272 u8 *buf = &wbuf[1]; 273 u8 *reg = buf - M41T80_REG_ALARM_MON; 274 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 275 struct i2c_msg msgs_in[] = { 276 { 277 .addr = client->addr, 278 .flags = 0, 279 .len = 1, 280 .buf = dt_addr, 281 }, 282 { 283 .addr = client->addr, 284 .flags = I2C_M_RD, 285 .len = M41T80_ALARM_REG_SIZE, 286 .buf = buf, 287 }, 288 }; 289 struct i2c_msg msgs[] = { 290 { 291 .addr = client->addr, 292 .flags = 0, 293 .len = 1 + M41T80_ALARM_REG_SIZE, 294 .buf = wbuf, 295 }, 296 }; 297 298 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 299 dev_err(&client->dev, "read error\n"); 300 return -EIO; 301 } 302 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE); 303 reg[M41T80_REG_ALARM_DAY] = 0; 304 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80); 305 reg[M41T80_REG_ALARM_MIN] = 0; 306 reg[M41T80_REG_ALARM_SEC] = 0; 307 308 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */ 309 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ? 310 BIN2BCD(t->time.tm_sec) : 0x80; 311 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ? 312 BIN2BCD(t->time.tm_min) : 0x80; 313 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ? 314 BIN2BCD(t->time.tm_hour) : 0x80; 315 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ? 316 BIN2BCD(t->time.tm_mday) : 0x80; 317 if (t->time.tm_mon >= 0) 318 reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1); 319 else 320 reg[M41T80_REG_ALARM_DAY] |= 0x40; 321 322 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 323 dev_err(&client->dev, "write error\n"); 324 return -EIO; 325 } 326 327 if (t->enabled) { 328 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE; 329 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 330 reg[M41T80_REG_ALARM_MON]) < 0) { 331 dev_err(&client->dev, "write error\n"); 332 return -EIO; 333 } 334 } 335 return 0; 336 } 337 338 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) 339 { 340 struct i2c_client *client = to_i2c_client(dev); 341 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */ 342 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 343 u8 *reg = buf - M41T80_REG_ALARM_MON; 344 struct i2c_msg msgs[] = { 345 { 346 .addr = client->addr, 347 .flags = 0, 348 .len = 1, 349 .buf = dt_addr, 350 }, 351 { 352 .addr = client->addr, 353 .flags = I2C_M_RD, 354 .len = M41T80_ALARM_REG_SIZE + 1, 355 .buf = buf, 356 }, 357 }; 358 359 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 360 dev_err(&client->dev, "read error\n"); 361 return -EIO; 362 } 363 t->time.tm_sec = -1; 364 t->time.tm_min = -1; 365 t->time.tm_hour = -1; 366 t->time.tm_mday = -1; 367 t->time.tm_mon = -1; 368 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80)) 369 t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f); 370 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80)) 371 t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f); 372 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80)) 373 t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f); 374 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80)) 375 t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f); 376 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40)) 377 t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1; 378 t->time.tm_year = -1; 379 t->time.tm_wday = -1; 380 t->time.tm_yday = -1; 381 t->time.tm_isdst = -1; 382 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE); 383 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF); 384 return 0; 385 } 386 387 static struct rtc_class_ops m41t80_rtc_ops = { 388 .read_time = m41t80_rtc_read_time, 389 .set_time = m41t80_rtc_set_time, 390 .read_alarm = m41t80_rtc_read_alarm, 391 .set_alarm = m41t80_rtc_set_alarm, 392 .proc = m41t80_rtc_proc, 393 .ioctl = m41t80_rtc_ioctl, 394 }; 395 396 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) 397 static ssize_t m41t80_sysfs_show_flags(struct device *dev, 398 struct device_attribute *attr, char *buf) 399 { 400 struct i2c_client *client = to_i2c_client(dev); 401 int val; 402 403 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 404 if (val < 0) 405 return -EIO; 406 return sprintf(buf, "%#x\n", val); 407 } 408 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); 409 410 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, 411 struct device_attribute *attr, char *buf) 412 { 413 struct i2c_client *client = to_i2c_client(dev); 414 int val; 415 416 val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 417 if (val < 0) 418 return -EIO; 419 val = (val >> 4) & 0xf; 420 switch (val) { 421 case 0: 422 break; 423 case 1: 424 val = 32768; 425 break; 426 default: 427 val = 32768 >> val; 428 } 429 return sprintf(buf, "%d\n", val); 430 } 431 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev, 432 struct device_attribute *attr, 433 const char *buf, size_t count) 434 { 435 struct i2c_client *client = to_i2c_client(dev); 436 int almon, sqw; 437 int val = simple_strtoul(buf, NULL, 0); 438 439 if (val) { 440 if (!is_power_of_2(val)) 441 return -EINVAL; 442 val = ilog2(val); 443 if (val == 15) 444 val = 1; 445 else if (val < 14) 446 val = 15 - val; 447 else 448 return -EINVAL; 449 } 450 /* disable SQW, set SQW frequency & re-enable */ 451 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 452 if (almon < 0) 453 return -EIO; 454 sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 455 if (sqw < 0) 456 return -EIO; 457 sqw = (sqw & 0x0f) | (val << 4); 458 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 459 almon & ~M41T80_ALMON_SQWE) < 0 || 460 i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0) 461 return -EIO; 462 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 463 almon | M41T80_ALMON_SQWE) < 0) 464 return -EIO; 465 return count; 466 } 467 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, 468 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); 469 470 static struct attribute *attrs[] = { 471 &dev_attr_flags.attr, 472 &dev_attr_sqwfreq.attr, 473 NULL, 474 }; 475 static struct attribute_group attr_group = { 476 .attrs = attrs, 477 }; 478 479 static int m41t80_sysfs_register(struct device *dev) 480 { 481 return sysfs_create_group(&dev->kobj, &attr_group); 482 } 483 #else 484 static int m41t80_sysfs_register(struct device *dev) 485 { 486 return 0; 487 } 488 #endif 489 490 #ifdef CONFIG_RTC_DRV_M41T80_WDT 491 /* 492 ***************************************************************************** 493 * 494 * Watchdog Driver 495 * 496 ***************************************************************************** 497 */ 498 static struct i2c_client *save_client; 499 500 /* Default margin */ 501 #define WD_TIMO 60 /* 1..31 seconds */ 502 503 static int wdt_margin = WD_TIMO; 504 module_param(wdt_margin, int, 0); 505 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); 506 507 static unsigned long wdt_is_open; 508 static int boot_flag; 509 510 /** 511 * wdt_ping: 512 * 513 * Reload counter one with the watchdog timeout. We don't bother reloading 514 * the cascade counter. 515 */ 516 static void wdt_ping(void) 517 { 518 unsigned char i2c_data[2]; 519 struct i2c_msg msgs1[1] = { 520 { 521 .addr = save_client->addr, 522 .flags = 0, 523 .len = 2, 524 .buf = i2c_data, 525 }, 526 }; 527 i2c_data[0] = 0x09; /* watchdog register */ 528 529 if (wdt_margin > 31) 530 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ 531 else 532 /* 533 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) 534 */ 535 i2c_data[1] = wdt_margin<<2 | 0x82; 536 537 i2c_transfer(save_client->adapter, msgs1, 1); 538 } 539 540 /** 541 * wdt_disable: 542 * 543 * disables watchdog. 544 */ 545 static void wdt_disable(void) 546 { 547 unsigned char i2c_data[2], i2c_buf[0x10]; 548 struct i2c_msg msgs0[2] = { 549 { 550 .addr = save_client->addr, 551 .flags = 0, 552 .len = 1, 553 .buf = i2c_data, 554 }, 555 { 556 .addr = save_client->addr, 557 .flags = I2C_M_RD, 558 .len = 1, 559 .buf = i2c_buf, 560 }, 561 }; 562 struct i2c_msg msgs1[1] = { 563 { 564 .addr = save_client->addr, 565 .flags = 0, 566 .len = 2, 567 .buf = i2c_data, 568 }, 569 }; 570 571 i2c_data[0] = 0x09; 572 i2c_transfer(save_client->adapter, msgs0, 2); 573 574 i2c_data[0] = 0x09; 575 i2c_data[1] = 0x00; 576 i2c_transfer(save_client->adapter, msgs1, 1); 577 } 578 579 /** 580 * wdt_write: 581 * @file: file handle to the watchdog 582 * @buf: buffer to write (unused as data does not matter here 583 * @count: count of bytes 584 * @ppos: pointer to the position to write. No seeks allowed 585 * 586 * A write to a watchdog device is defined as a keepalive signal. Any 587 * write of data will do, as we we don't define content meaning. 588 */ 589 static ssize_t wdt_write(struct file *file, const char __user *buf, 590 size_t count, loff_t *ppos) 591 { 592 /* Can't seek (pwrite) on this device 593 if (ppos != &file->f_pos) 594 return -ESPIPE; 595 */ 596 if (count) { 597 wdt_ping(); 598 return 1; 599 } 600 return 0; 601 } 602 603 static ssize_t wdt_read(struct file *file, char __user *buf, 604 size_t count, loff_t *ppos) 605 { 606 return 0; 607 } 608 609 /** 610 * wdt_ioctl: 611 * @inode: inode of the device 612 * @file: file handle to the device 613 * @cmd: watchdog command 614 * @arg: argument pointer 615 * 616 * The watchdog API defines a common set of functions for all watchdogs 617 * according to their available features. We only actually usefully support 618 * querying capabilities and current status. 619 */ 620 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 621 unsigned long arg) 622 { 623 int new_margin, rv; 624 static struct watchdog_info ident = { 625 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | 626 WDIOF_SETTIMEOUT, 627 .firmware_version = 1, 628 .identity = "M41T80 WTD" 629 }; 630 631 switch (cmd) { 632 case WDIOC_GETSUPPORT: 633 return copy_to_user((struct watchdog_info __user *)arg, &ident, 634 sizeof(ident)) ? -EFAULT : 0; 635 636 case WDIOC_GETSTATUS: 637 case WDIOC_GETBOOTSTATUS: 638 return put_user(boot_flag, (int __user *)arg); 639 case WDIOC_KEEPALIVE: 640 wdt_ping(); 641 return 0; 642 case WDIOC_SETTIMEOUT: 643 if (get_user(new_margin, (int __user *)arg)) 644 return -EFAULT; 645 /* Arbitrary, can't find the card's limits */ 646 if (new_margin < 1 || new_margin > 124) 647 return -EINVAL; 648 wdt_margin = new_margin; 649 wdt_ping(); 650 /* Fall */ 651 case WDIOC_GETTIMEOUT: 652 return put_user(wdt_margin, (int __user *)arg); 653 654 case WDIOC_SETOPTIONS: 655 if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) 656 return -EFAULT; 657 658 if (rv & WDIOS_DISABLECARD) { 659 printk(KERN_INFO 660 "rtc-m41t80: disable watchdog\n"); 661 wdt_disable(); 662 } 663 664 if (rv & WDIOS_ENABLECARD) { 665 printk(KERN_INFO 666 "rtc-m41t80: enable watchdog\n"); 667 wdt_ping(); 668 } 669 670 return -EINVAL; 671 } 672 return -ENOTTY; 673 } 674 675 /** 676 * wdt_open: 677 * @inode: inode of device 678 * @file: file handle to device 679 * 680 */ 681 static int wdt_open(struct inode *inode, struct file *file) 682 { 683 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { 684 if (test_and_set_bit(0, &wdt_is_open)) 685 return -EBUSY; 686 /* 687 * Activate 688 */ 689 wdt_is_open = 1; 690 return 0; 691 } 692 return -ENODEV; 693 } 694 695 /** 696 * wdt_close: 697 * @inode: inode to board 698 * @file: file handle to board 699 * 700 */ 701 static int wdt_release(struct inode *inode, struct file *file) 702 { 703 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 704 clear_bit(0, &wdt_is_open); 705 return 0; 706 } 707 708 /** 709 * notify_sys: 710 * @this: our notifier block 711 * @code: the event being reported 712 * @unused: unused 713 * 714 * Our notifier is called on system shutdowns. We want to turn the card 715 * off at reboot otherwise the machine will reboot again during memory 716 * test or worse yet during the following fsck. This would suck, in fact 717 * trust me - if it happens it does suck. 718 */ 719 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 720 void *unused) 721 { 722 if (code == SYS_DOWN || code == SYS_HALT) 723 /* Disable Watchdog */ 724 wdt_disable(); 725 return NOTIFY_DONE; 726 } 727 728 static const struct file_operations wdt_fops = { 729 .owner = THIS_MODULE, 730 .read = wdt_read, 731 .ioctl = wdt_ioctl, 732 .write = wdt_write, 733 .open = wdt_open, 734 .release = wdt_release, 735 }; 736 737 static struct miscdevice wdt_dev = { 738 .minor = WATCHDOG_MINOR, 739 .name = "watchdog", 740 .fops = &wdt_fops, 741 }; 742 743 /* 744 * The WDT card needs to learn about soft shutdowns in order to 745 * turn the timebomb registers off. 746 */ 747 static struct notifier_block wdt_notifier = { 748 .notifier_call = wdt_notify_sys, 749 }; 750 #endif /* CONFIG_RTC_DRV_M41T80_WDT */ 751 752 /* 753 ***************************************************************************** 754 * 755 * Driver Interface 756 * 757 ***************************************************************************** 758 */ 759 static int m41t80_probe(struct i2c_client *client) 760 { 761 int i, rc = 0; 762 struct rtc_device *rtc = NULL; 763 struct rtc_time tm; 764 const struct m41t80_chip_info *chip; 765 struct m41t80_data *clientdata = NULL; 766 767 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C 768 | I2C_FUNC_SMBUS_BYTE_DATA)) { 769 rc = -ENODEV; 770 goto exit; 771 } 772 773 dev_info(&client->dev, 774 "chip found, driver version " DRV_VERSION "\n"); 775 776 chip = NULL; 777 for (i = 0; i < ARRAY_SIZE(m41t80_chip_info_tbl); i++) { 778 if (!strcmp(m41t80_chip_info_tbl[i].name, client->name)) { 779 chip = &m41t80_chip_info_tbl[i]; 780 break; 781 } 782 } 783 if (!chip) { 784 dev_err(&client->dev, "%s is not supported\n", client->name); 785 rc = -ENODEV; 786 goto exit; 787 } 788 789 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL); 790 if (!clientdata) { 791 rc = -ENOMEM; 792 goto exit; 793 } 794 795 rtc = rtc_device_register(client->name, &client->dev, 796 &m41t80_rtc_ops, THIS_MODULE); 797 if (IS_ERR(rtc)) { 798 rc = PTR_ERR(rtc); 799 rtc = NULL; 800 goto exit; 801 } 802 803 clientdata->rtc = rtc; 804 clientdata->chip = chip; 805 i2c_set_clientdata(client, clientdata); 806 807 /* Make sure HT (Halt Update) bit is cleared */ 808 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); 809 if (rc < 0) 810 goto ht_err; 811 812 if (rc & M41T80_ALHOUR_HT) { 813 if (chip->features & M41T80_FEATURE_HT) { 814 m41t80_get_datetime(client, &tm); 815 dev_info(&client->dev, "HT bit was set!\n"); 816 dev_info(&client->dev, 817 "Power Down at " 818 "%04i-%02i-%02i %02i:%02i:%02i\n", 819 tm.tm_year + 1900, 820 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 821 tm.tm_min, tm.tm_sec); 822 } 823 if (i2c_smbus_write_byte_data(client, 824 M41T80_REG_ALARM_HOUR, 825 rc & ~M41T80_ALHOUR_HT) < 0) 826 goto ht_err; 827 } 828 829 /* Make sure ST (stop) bit is cleared */ 830 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); 831 if (rc < 0) 832 goto st_err; 833 834 if (rc & M41T80_SEC_ST) { 835 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC, 836 rc & ~M41T80_SEC_ST) < 0) 837 goto st_err; 838 } 839 840 rc = m41t80_sysfs_register(&client->dev); 841 if (rc) 842 goto exit; 843 844 #ifdef CONFIG_RTC_DRV_M41T80_WDT 845 if (chip->features & M41T80_FEATURE_HT) { 846 rc = misc_register(&wdt_dev); 847 if (rc) 848 goto exit; 849 rc = register_reboot_notifier(&wdt_notifier); 850 if (rc) { 851 misc_deregister(&wdt_dev); 852 goto exit; 853 } 854 save_client = client; 855 } 856 #endif 857 return 0; 858 859 st_err: 860 rc = -EIO; 861 dev_err(&client->dev, "Can't clear ST bit\n"); 862 goto exit; 863 ht_err: 864 rc = -EIO; 865 dev_err(&client->dev, "Can't clear HT bit\n"); 866 goto exit; 867 868 exit: 869 if (rtc) 870 rtc_device_unregister(rtc); 871 kfree(clientdata); 872 return rc; 873 } 874 875 static int m41t80_remove(struct i2c_client *client) 876 { 877 struct m41t80_data *clientdata = i2c_get_clientdata(client); 878 struct rtc_device *rtc = clientdata->rtc; 879 880 #ifdef CONFIG_RTC_DRV_M41T80_WDT 881 if (clientdata->chip->features & M41T80_FEATURE_HT) { 882 misc_deregister(&wdt_dev); 883 unregister_reboot_notifier(&wdt_notifier); 884 } 885 #endif 886 if (rtc) 887 rtc_device_unregister(rtc); 888 kfree(clientdata); 889 890 return 0; 891 } 892 893 static struct i2c_driver m41t80_driver = { 894 .driver = { 895 .name = "rtc-m41t80", 896 }, 897 .probe = m41t80_probe, 898 .remove = m41t80_remove, 899 }; 900 901 static int __init m41t80_rtc_init(void) 902 { 903 return i2c_add_driver(&m41t80_driver); 904 } 905 906 static void __exit m41t80_rtc_exit(void) 907 { 908 i2c_del_driver(&m41t80_driver); 909 } 910 911 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); 912 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); 913 MODULE_LICENSE("GPL"); 914 MODULE_VERSION(DRV_VERSION); 915 916 module_init(m41t80_rtc_init); 917 module_exit(m41t80_rtc_exit); 918