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 static const struct i2c_device_id m41t80_id[] = { 64 { "m41t80", 0 }, 65 { "m41t81", M41T80_FEATURE_HT }, 66 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 67 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 68 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 69 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 70 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 71 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 72 { } 73 }; 74 MODULE_DEVICE_TABLE(i2c, m41t80_id); 75 76 struct m41t80_data { 77 u8 features; 78 struct rtc_device *rtc; 79 }; 80 81 static int m41t80_get_datetime(struct i2c_client *client, 82 struct rtc_time *tm) 83 { 84 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; 85 struct i2c_msg msgs[] = { 86 { 87 .addr = client->addr, 88 .flags = 0, 89 .len = 1, 90 .buf = dt_addr, 91 }, 92 { 93 .addr = client->addr, 94 .flags = I2C_M_RD, 95 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 96 .buf = buf + M41T80_REG_SEC, 97 }, 98 }; 99 100 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 101 dev_err(&client->dev, "read error\n"); 102 return -EIO; 103 } 104 105 tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f); 106 tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f); 107 tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f); 108 tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f); 109 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; 110 tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1; 111 112 /* assume 20YY not 19YY, and ignore the Century Bit */ 113 tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100; 114 return 0; 115 } 116 117 /* Sets the given date and time to the real time clock. */ 118 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) 119 { 120 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; 121 u8 *buf = &wbuf[1]; 122 u8 dt_addr[1] = { M41T80_REG_SEC }; 123 struct i2c_msg msgs_in[] = { 124 { 125 .addr = client->addr, 126 .flags = 0, 127 .len = 1, 128 .buf = dt_addr, 129 }, 130 { 131 .addr = client->addr, 132 .flags = I2C_M_RD, 133 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 134 .buf = buf + M41T80_REG_SEC, 135 }, 136 }; 137 struct i2c_msg msgs[] = { 138 { 139 .addr = client->addr, 140 .flags = 0, 141 .len = 1 + M41T80_DATETIME_REG_SIZE, 142 .buf = wbuf, 143 }, 144 }; 145 146 /* Read current reg values into buf[1..7] */ 147 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 148 dev_err(&client->dev, "read error\n"); 149 return -EIO; 150 } 151 152 wbuf[0] = 0; /* offset into rtc's regs */ 153 /* Merge time-data and register flags into buf[0..7] */ 154 buf[M41T80_REG_SSEC] = 0; 155 buf[M41T80_REG_SEC] = 156 BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); 157 buf[M41T80_REG_MIN] = 158 BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); 159 buf[M41T80_REG_HOUR] = 160 BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ; 161 buf[M41T80_REG_WDAY] = 162 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); 163 buf[M41T80_REG_DAY] = 164 BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); 165 buf[M41T80_REG_MON] = 166 BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); 167 /* assume 20YY not 19YY */ 168 buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100); 169 170 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 171 dev_err(&client->dev, "write error\n"); 172 return -EIO; 173 } 174 return 0; 175 } 176 177 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) 178 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) 179 { 180 struct i2c_client *client = to_i2c_client(dev); 181 struct m41t80_data *clientdata = i2c_get_clientdata(client); 182 u8 reg; 183 184 if (clientdata->features & M41T80_FEATURE_BL) { 185 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 186 seq_printf(seq, "battery\t\t: %s\n", 187 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); 188 } 189 return 0; 190 } 191 #else 192 #define m41t80_rtc_proc NULL 193 #endif 194 195 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) 196 { 197 return m41t80_get_datetime(to_i2c_client(dev), tm); 198 } 199 200 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) 201 { 202 return m41t80_set_datetime(to_i2c_client(dev), tm); 203 } 204 205 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) 206 static int 207 m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 208 { 209 struct i2c_client *client = to_i2c_client(dev); 210 int rc; 211 212 switch (cmd) { 213 case RTC_AIE_OFF: 214 case RTC_AIE_ON: 215 break; 216 default: 217 return -ENOIOCTLCMD; 218 } 219 220 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 221 if (rc < 0) 222 goto err; 223 switch (cmd) { 224 case RTC_AIE_OFF: 225 rc &= ~M41T80_ALMON_AFE; 226 break; 227 case RTC_AIE_ON: 228 rc |= M41T80_ALMON_AFE; 229 break; 230 } 231 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0) 232 goto err; 233 return 0; 234 err: 235 return -EIO; 236 } 237 #else 238 #define m41t80_rtc_ioctl NULL 239 #endif 240 241 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t) 242 { 243 struct i2c_client *client = to_i2c_client(dev); 244 u8 wbuf[1 + M41T80_ALARM_REG_SIZE]; 245 u8 *buf = &wbuf[1]; 246 u8 *reg = buf - M41T80_REG_ALARM_MON; 247 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 248 struct i2c_msg msgs_in[] = { 249 { 250 .addr = client->addr, 251 .flags = 0, 252 .len = 1, 253 .buf = dt_addr, 254 }, 255 { 256 .addr = client->addr, 257 .flags = I2C_M_RD, 258 .len = M41T80_ALARM_REG_SIZE, 259 .buf = buf, 260 }, 261 }; 262 struct i2c_msg msgs[] = { 263 { 264 .addr = client->addr, 265 .flags = 0, 266 .len = 1 + M41T80_ALARM_REG_SIZE, 267 .buf = wbuf, 268 }, 269 }; 270 271 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 272 dev_err(&client->dev, "read error\n"); 273 return -EIO; 274 } 275 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE); 276 reg[M41T80_REG_ALARM_DAY] = 0; 277 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80); 278 reg[M41T80_REG_ALARM_MIN] = 0; 279 reg[M41T80_REG_ALARM_SEC] = 0; 280 281 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */ 282 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ? 283 BIN2BCD(t->time.tm_sec) : 0x80; 284 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ? 285 BIN2BCD(t->time.tm_min) : 0x80; 286 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ? 287 BIN2BCD(t->time.tm_hour) : 0x80; 288 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ? 289 BIN2BCD(t->time.tm_mday) : 0x80; 290 if (t->time.tm_mon >= 0) 291 reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1); 292 else 293 reg[M41T80_REG_ALARM_DAY] |= 0x40; 294 295 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 296 dev_err(&client->dev, "write error\n"); 297 return -EIO; 298 } 299 300 if (t->enabled) { 301 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE; 302 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 303 reg[M41T80_REG_ALARM_MON]) < 0) { 304 dev_err(&client->dev, "write error\n"); 305 return -EIO; 306 } 307 } 308 return 0; 309 } 310 311 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) 312 { 313 struct i2c_client *client = to_i2c_client(dev); 314 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */ 315 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 316 u8 *reg = buf - M41T80_REG_ALARM_MON; 317 struct i2c_msg msgs[] = { 318 { 319 .addr = client->addr, 320 .flags = 0, 321 .len = 1, 322 .buf = dt_addr, 323 }, 324 { 325 .addr = client->addr, 326 .flags = I2C_M_RD, 327 .len = M41T80_ALARM_REG_SIZE + 1, 328 .buf = buf, 329 }, 330 }; 331 332 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 333 dev_err(&client->dev, "read error\n"); 334 return -EIO; 335 } 336 t->time.tm_sec = -1; 337 t->time.tm_min = -1; 338 t->time.tm_hour = -1; 339 t->time.tm_mday = -1; 340 t->time.tm_mon = -1; 341 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80)) 342 t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f); 343 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80)) 344 t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f); 345 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80)) 346 t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f); 347 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80)) 348 t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f); 349 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40)) 350 t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1; 351 t->time.tm_year = -1; 352 t->time.tm_wday = -1; 353 t->time.tm_yday = -1; 354 t->time.tm_isdst = -1; 355 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE); 356 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF); 357 return 0; 358 } 359 360 static struct rtc_class_ops m41t80_rtc_ops = { 361 .read_time = m41t80_rtc_read_time, 362 .set_time = m41t80_rtc_set_time, 363 .read_alarm = m41t80_rtc_read_alarm, 364 .set_alarm = m41t80_rtc_set_alarm, 365 .proc = m41t80_rtc_proc, 366 .ioctl = m41t80_rtc_ioctl, 367 }; 368 369 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) 370 static ssize_t m41t80_sysfs_show_flags(struct device *dev, 371 struct device_attribute *attr, char *buf) 372 { 373 struct i2c_client *client = to_i2c_client(dev); 374 int val; 375 376 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 377 if (val < 0) 378 return -EIO; 379 return sprintf(buf, "%#x\n", val); 380 } 381 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); 382 383 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, 384 struct device_attribute *attr, char *buf) 385 { 386 struct i2c_client *client = to_i2c_client(dev); 387 int val; 388 389 val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 390 if (val < 0) 391 return -EIO; 392 val = (val >> 4) & 0xf; 393 switch (val) { 394 case 0: 395 break; 396 case 1: 397 val = 32768; 398 break; 399 default: 400 val = 32768 >> val; 401 } 402 return sprintf(buf, "%d\n", val); 403 } 404 static ssize_t m41t80_sysfs_set_sqwfreq(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 int almon, sqw; 410 int val = simple_strtoul(buf, NULL, 0); 411 412 if (val) { 413 if (!is_power_of_2(val)) 414 return -EINVAL; 415 val = ilog2(val); 416 if (val == 15) 417 val = 1; 418 else if (val < 14) 419 val = 15 - val; 420 else 421 return -EINVAL; 422 } 423 /* disable SQW, set SQW frequency & re-enable */ 424 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 425 if (almon < 0) 426 return -EIO; 427 sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 428 if (sqw < 0) 429 return -EIO; 430 sqw = (sqw & 0x0f) | (val << 4); 431 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 432 almon & ~M41T80_ALMON_SQWE) < 0 || 433 i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0) 434 return -EIO; 435 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 436 almon | M41T80_ALMON_SQWE) < 0) 437 return -EIO; 438 return count; 439 } 440 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, 441 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); 442 443 static struct attribute *attrs[] = { 444 &dev_attr_flags.attr, 445 &dev_attr_sqwfreq.attr, 446 NULL, 447 }; 448 static struct attribute_group attr_group = { 449 .attrs = attrs, 450 }; 451 452 static int m41t80_sysfs_register(struct device *dev) 453 { 454 return sysfs_create_group(&dev->kobj, &attr_group); 455 } 456 #else 457 static int m41t80_sysfs_register(struct device *dev) 458 { 459 return 0; 460 } 461 #endif 462 463 #ifdef CONFIG_RTC_DRV_M41T80_WDT 464 /* 465 ***************************************************************************** 466 * 467 * Watchdog Driver 468 * 469 ***************************************************************************** 470 */ 471 static struct i2c_client *save_client; 472 473 /* Default margin */ 474 #define WD_TIMO 60 /* 1..31 seconds */ 475 476 static int wdt_margin = WD_TIMO; 477 module_param(wdt_margin, int, 0); 478 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); 479 480 static unsigned long wdt_is_open; 481 static int boot_flag; 482 483 /** 484 * wdt_ping: 485 * 486 * Reload counter one with the watchdog timeout. We don't bother reloading 487 * the cascade counter. 488 */ 489 static void wdt_ping(void) 490 { 491 unsigned char i2c_data[2]; 492 struct i2c_msg msgs1[1] = { 493 { 494 .addr = save_client->addr, 495 .flags = 0, 496 .len = 2, 497 .buf = i2c_data, 498 }, 499 }; 500 i2c_data[0] = 0x09; /* watchdog register */ 501 502 if (wdt_margin > 31) 503 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ 504 else 505 /* 506 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) 507 */ 508 i2c_data[1] = wdt_margin<<2 | 0x82; 509 510 i2c_transfer(save_client->adapter, msgs1, 1); 511 } 512 513 /** 514 * wdt_disable: 515 * 516 * disables watchdog. 517 */ 518 static void wdt_disable(void) 519 { 520 unsigned char i2c_data[2], i2c_buf[0x10]; 521 struct i2c_msg msgs0[2] = { 522 { 523 .addr = save_client->addr, 524 .flags = 0, 525 .len = 1, 526 .buf = i2c_data, 527 }, 528 { 529 .addr = save_client->addr, 530 .flags = I2C_M_RD, 531 .len = 1, 532 .buf = i2c_buf, 533 }, 534 }; 535 struct i2c_msg msgs1[1] = { 536 { 537 .addr = save_client->addr, 538 .flags = 0, 539 .len = 2, 540 .buf = i2c_data, 541 }, 542 }; 543 544 i2c_data[0] = 0x09; 545 i2c_transfer(save_client->adapter, msgs0, 2); 546 547 i2c_data[0] = 0x09; 548 i2c_data[1] = 0x00; 549 i2c_transfer(save_client->adapter, msgs1, 1); 550 } 551 552 /** 553 * wdt_write: 554 * @file: file handle to the watchdog 555 * @buf: buffer to write (unused as data does not matter here 556 * @count: count of bytes 557 * @ppos: pointer to the position to write. No seeks allowed 558 * 559 * A write to a watchdog device is defined as a keepalive signal. Any 560 * write of data will do, as we we don't define content meaning. 561 */ 562 static ssize_t wdt_write(struct file *file, const char __user *buf, 563 size_t count, loff_t *ppos) 564 { 565 /* Can't seek (pwrite) on this device 566 if (ppos != &file->f_pos) 567 return -ESPIPE; 568 */ 569 if (count) { 570 wdt_ping(); 571 return 1; 572 } 573 return 0; 574 } 575 576 static ssize_t wdt_read(struct file *file, char __user *buf, 577 size_t count, loff_t *ppos) 578 { 579 return 0; 580 } 581 582 /** 583 * wdt_ioctl: 584 * @inode: inode of the device 585 * @file: file handle to the device 586 * @cmd: watchdog command 587 * @arg: argument pointer 588 * 589 * The watchdog API defines a common set of functions for all watchdogs 590 * according to their available features. We only actually usefully support 591 * querying capabilities and current status. 592 */ 593 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 594 unsigned long arg) 595 { 596 int new_margin, rv; 597 static struct watchdog_info ident = { 598 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | 599 WDIOF_SETTIMEOUT, 600 .firmware_version = 1, 601 .identity = "M41T80 WTD" 602 }; 603 604 switch (cmd) { 605 case WDIOC_GETSUPPORT: 606 return copy_to_user((struct watchdog_info __user *)arg, &ident, 607 sizeof(ident)) ? -EFAULT : 0; 608 609 case WDIOC_GETSTATUS: 610 case WDIOC_GETBOOTSTATUS: 611 return put_user(boot_flag, (int __user *)arg); 612 case WDIOC_KEEPALIVE: 613 wdt_ping(); 614 return 0; 615 case WDIOC_SETTIMEOUT: 616 if (get_user(new_margin, (int __user *)arg)) 617 return -EFAULT; 618 /* Arbitrary, can't find the card's limits */ 619 if (new_margin < 1 || new_margin > 124) 620 return -EINVAL; 621 wdt_margin = new_margin; 622 wdt_ping(); 623 /* Fall */ 624 case WDIOC_GETTIMEOUT: 625 return put_user(wdt_margin, (int __user *)arg); 626 627 case WDIOC_SETOPTIONS: 628 if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) 629 return -EFAULT; 630 631 if (rv & WDIOS_DISABLECARD) { 632 printk(KERN_INFO 633 "rtc-m41t80: disable watchdog\n"); 634 wdt_disable(); 635 } 636 637 if (rv & WDIOS_ENABLECARD) { 638 printk(KERN_INFO 639 "rtc-m41t80: enable watchdog\n"); 640 wdt_ping(); 641 } 642 643 return -EINVAL; 644 } 645 return -ENOTTY; 646 } 647 648 /** 649 * wdt_open: 650 * @inode: inode of device 651 * @file: file handle to device 652 * 653 */ 654 static int wdt_open(struct inode *inode, struct file *file) 655 { 656 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { 657 if (test_and_set_bit(0, &wdt_is_open)) 658 return -EBUSY; 659 /* 660 * Activate 661 */ 662 wdt_is_open = 1; 663 return 0; 664 } 665 return -ENODEV; 666 } 667 668 /** 669 * wdt_close: 670 * @inode: inode to board 671 * @file: file handle to board 672 * 673 */ 674 static int wdt_release(struct inode *inode, struct file *file) 675 { 676 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 677 clear_bit(0, &wdt_is_open); 678 return 0; 679 } 680 681 /** 682 * notify_sys: 683 * @this: our notifier block 684 * @code: the event being reported 685 * @unused: unused 686 * 687 * Our notifier is called on system shutdowns. We want to turn the card 688 * off at reboot otherwise the machine will reboot again during memory 689 * test or worse yet during the following fsck. This would suck, in fact 690 * trust me - if it happens it does suck. 691 */ 692 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 693 void *unused) 694 { 695 if (code == SYS_DOWN || code == SYS_HALT) 696 /* Disable Watchdog */ 697 wdt_disable(); 698 return NOTIFY_DONE; 699 } 700 701 static const struct file_operations wdt_fops = { 702 .owner = THIS_MODULE, 703 .read = wdt_read, 704 .ioctl = wdt_ioctl, 705 .write = wdt_write, 706 .open = wdt_open, 707 .release = wdt_release, 708 }; 709 710 static struct miscdevice wdt_dev = { 711 .minor = WATCHDOG_MINOR, 712 .name = "watchdog", 713 .fops = &wdt_fops, 714 }; 715 716 /* 717 * The WDT card needs to learn about soft shutdowns in order to 718 * turn the timebomb registers off. 719 */ 720 static struct notifier_block wdt_notifier = { 721 .notifier_call = wdt_notify_sys, 722 }; 723 #endif /* CONFIG_RTC_DRV_M41T80_WDT */ 724 725 /* 726 ***************************************************************************** 727 * 728 * Driver Interface 729 * 730 ***************************************************************************** 731 */ 732 static int m41t80_probe(struct i2c_client *client, 733 const struct i2c_device_id *id) 734 { 735 int rc = 0; 736 struct rtc_device *rtc = NULL; 737 struct rtc_time tm; 738 struct m41t80_data *clientdata = NULL; 739 740 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C 741 | I2C_FUNC_SMBUS_BYTE_DATA)) { 742 rc = -ENODEV; 743 goto exit; 744 } 745 746 dev_info(&client->dev, 747 "chip found, driver version " DRV_VERSION "\n"); 748 749 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL); 750 if (!clientdata) { 751 rc = -ENOMEM; 752 goto exit; 753 } 754 755 rtc = rtc_device_register(client->name, &client->dev, 756 &m41t80_rtc_ops, THIS_MODULE); 757 if (IS_ERR(rtc)) { 758 rc = PTR_ERR(rtc); 759 rtc = NULL; 760 goto exit; 761 } 762 763 clientdata->rtc = rtc; 764 clientdata->features = id->driver_data; 765 i2c_set_clientdata(client, clientdata); 766 767 /* Make sure HT (Halt Update) bit is cleared */ 768 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); 769 if (rc < 0) 770 goto ht_err; 771 772 if (rc & M41T80_ALHOUR_HT) { 773 if (clientdata->features & M41T80_FEATURE_HT) { 774 m41t80_get_datetime(client, &tm); 775 dev_info(&client->dev, "HT bit was set!\n"); 776 dev_info(&client->dev, 777 "Power Down at " 778 "%04i-%02i-%02i %02i:%02i:%02i\n", 779 tm.tm_year + 1900, 780 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 781 tm.tm_min, tm.tm_sec); 782 } 783 if (i2c_smbus_write_byte_data(client, 784 M41T80_REG_ALARM_HOUR, 785 rc & ~M41T80_ALHOUR_HT) < 0) 786 goto ht_err; 787 } 788 789 /* Make sure ST (stop) bit is cleared */ 790 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); 791 if (rc < 0) 792 goto st_err; 793 794 if (rc & M41T80_SEC_ST) { 795 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC, 796 rc & ~M41T80_SEC_ST) < 0) 797 goto st_err; 798 } 799 800 rc = m41t80_sysfs_register(&client->dev); 801 if (rc) 802 goto exit; 803 804 #ifdef CONFIG_RTC_DRV_M41T80_WDT 805 if (clientdata->features & M41T80_FEATURE_HT) { 806 rc = misc_register(&wdt_dev); 807 if (rc) 808 goto exit; 809 rc = register_reboot_notifier(&wdt_notifier); 810 if (rc) { 811 misc_deregister(&wdt_dev); 812 goto exit; 813 } 814 save_client = client; 815 } 816 #endif 817 return 0; 818 819 st_err: 820 rc = -EIO; 821 dev_err(&client->dev, "Can't clear ST bit\n"); 822 goto exit; 823 ht_err: 824 rc = -EIO; 825 dev_err(&client->dev, "Can't clear HT bit\n"); 826 goto exit; 827 828 exit: 829 if (rtc) 830 rtc_device_unregister(rtc); 831 kfree(clientdata); 832 return rc; 833 } 834 835 static int m41t80_remove(struct i2c_client *client) 836 { 837 struct m41t80_data *clientdata = i2c_get_clientdata(client); 838 struct rtc_device *rtc = clientdata->rtc; 839 840 #ifdef CONFIG_RTC_DRV_M41T80_WDT 841 if (clientdata->features & M41T80_FEATURE_HT) { 842 misc_deregister(&wdt_dev); 843 unregister_reboot_notifier(&wdt_notifier); 844 } 845 #endif 846 if (rtc) 847 rtc_device_unregister(rtc); 848 kfree(clientdata); 849 850 return 0; 851 } 852 853 static struct i2c_driver m41t80_driver = { 854 .driver = { 855 .name = "rtc-m41t80", 856 }, 857 .probe = m41t80_probe, 858 .remove = m41t80_remove, 859 .id_table = m41t80_id, 860 }; 861 862 static int __init m41t80_rtc_init(void) 863 { 864 return i2c_add_driver(&m41t80_driver); 865 } 866 867 static void __exit m41t80_rtc_exit(void) 868 { 869 i2c_del_driver(&m41t80_driver); 870 } 871 872 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); 873 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); 874 MODULE_LICENSE("GPL"); 875 MODULE_VERSION(DRV_VERSION); 876 877 module_init(m41t80_rtc_init); 878 module_exit(m41t80_rtc_exit); 879