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/bcd.h> 17 #include <linux/i2c.h> 18 #include <linux/init.h> 19 #include <linux/kernel.h> 20 #include <linux/module.h> 21 #include <linux/rtc.h> 22 #include <linux/slab.h> 23 #include <linux/smp_lock.h> 24 #include <linux/string.h> 25 #ifdef CONFIG_RTC_DRV_M41T80_WDT 26 #include <linux/fs.h> 27 #include <linux/ioctl.h> 28 #include <linux/miscdevice.h> 29 #include <linux/reboot.h> 30 #include <linux/watchdog.h> 31 #endif 32 33 #define M41T80_REG_SSEC 0 34 #define M41T80_REG_SEC 1 35 #define M41T80_REG_MIN 2 36 #define M41T80_REG_HOUR 3 37 #define M41T80_REG_WDAY 4 38 #define M41T80_REG_DAY 5 39 #define M41T80_REG_MON 6 40 #define M41T80_REG_YEAR 7 41 #define M41T80_REG_ALARM_MON 0xa 42 #define M41T80_REG_ALARM_DAY 0xb 43 #define M41T80_REG_ALARM_HOUR 0xc 44 #define M41T80_REG_ALARM_MIN 0xd 45 #define M41T80_REG_ALARM_SEC 0xe 46 #define M41T80_REG_FLAGS 0xf 47 #define M41T80_REG_SQW 0x13 48 49 #define M41T80_DATETIME_REG_SIZE (M41T80_REG_YEAR + 1) 50 #define M41T80_ALARM_REG_SIZE \ 51 (M41T80_REG_ALARM_SEC + 1 - M41T80_REG_ALARM_MON) 52 53 #define M41T80_SEC_ST (1 << 7) /* ST: Stop Bit */ 54 #define M41T80_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ 55 #define M41T80_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ 56 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ 57 #define M41T80_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ 58 #define M41T80_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ 59 60 #define M41T80_FEATURE_HT (1 << 0) 61 #define M41T80_FEATURE_BL (1 << 1) 62 63 #define DRV_VERSION "0.05" 64 65 static const struct i2c_device_id m41t80_id[] = { 66 { "m41t80", 0 }, 67 { "m41t81", M41T80_FEATURE_HT }, 68 { "m41t81s", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 69 { "m41t82", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 70 { "m41t83", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 71 { "m41st84", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 72 { "m41st85", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 73 { "m41st87", M41T80_FEATURE_HT | M41T80_FEATURE_BL }, 74 { } 75 }; 76 MODULE_DEVICE_TABLE(i2c, m41t80_id); 77 78 struct m41t80_data { 79 u8 features; 80 struct rtc_device *rtc; 81 }; 82 83 static int m41t80_get_datetime(struct i2c_client *client, 84 struct rtc_time *tm) 85 { 86 u8 buf[M41T80_DATETIME_REG_SIZE], dt_addr[1] = { M41T80_REG_SEC }; 87 struct i2c_msg msgs[] = { 88 { 89 .addr = client->addr, 90 .flags = 0, 91 .len = 1, 92 .buf = dt_addr, 93 }, 94 { 95 .addr = client->addr, 96 .flags = I2C_M_RD, 97 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 98 .buf = buf + M41T80_REG_SEC, 99 }, 100 }; 101 102 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 103 dev_err(&client->dev, "read error\n"); 104 return -EIO; 105 } 106 107 tm->tm_sec = BCD2BIN(buf[M41T80_REG_SEC] & 0x7f); 108 tm->tm_min = BCD2BIN(buf[M41T80_REG_MIN] & 0x7f); 109 tm->tm_hour = BCD2BIN(buf[M41T80_REG_HOUR] & 0x3f); 110 tm->tm_mday = BCD2BIN(buf[M41T80_REG_DAY] & 0x3f); 111 tm->tm_wday = buf[M41T80_REG_WDAY] & 0x07; 112 tm->tm_mon = BCD2BIN(buf[M41T80_REG_MON] & 0x1f) - 1; 113 114 /* assume 20YY not 19YY, and ignore the Century Bit */ 115 tm->tm_year = BCD2BIN(buf[M41T80_REG_YEAR]) + 100; 116 return 0; 117 } 118 119 /* Sets the given date and time to the real time clock. */ 120 static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) 121 { 122 u8 wbuf[1 + M41T80_DATETIME_REG_SIZE]; 123 u8 *buf = &wbuf[1]; 124 u8 dt_addr[1] = { M41T80_REG_SEC }; 125 struct i2c_msg msgs_in[] = { 126 { 127 .addr = client->addr, 128 .flags = 0, 129 .len = 1, 130 .buf = dt_addr, 131 }, 132 { 133 .addr = client->addr, 134 .flags = I2C_M_RD, 135 .len = M41T80_DATETIME_REG_SIZE - M41T80_REG_SEC, 136 .buf = buf + M41T80_REG_SEC, 137 }, 138 }; 139 struct i2c_msg msgs[] = { 140 { 141 .addr = client->addr, 142 .flags = 0, 143 .len = 1 + M41T80_DATETIME_REG_SIZE, 144 .buf = wbuf, 145 }, 146 }; 147 148 /* Read current reg values into buf[1..7] */ 149 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 150 dev_err(&client->dev, "read error\n"); 151 return -EIO; 152 } 153 154 wbuf[0] = 0; /* offset into rtc's regs */ 155 /* Merge time-data and register flags into buf[0..7] */ 156 buf[M41T80_REG_SSEC] = 0; 157 buf[M41T80_REG_SEC] = 158 BIN2BCD(tm->tm_sec) | (buf[M41T80_REG_SEC] & ~0x7f); 159 buf[M41T80_REG_MIN] = 160 BIN2BCD(tm->tm_min) | (buf[M41T80_REG_MIN] & ~0x7f); 161 buf[M41T80_REG_HOUR] = 162 BIN2BCD(tm->tm_hour) | (buf[M41T80_REG_HOUR] & ~0x3f) ; 163 buf[M41T80_REG_WDAY] = 164 (tm->tm_wday & 0x07) | (buf[M41T80_REG_WDAY] & ~0x07); 165 buf[M41T80_REG_DAY] = 166 BIN2BCD(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); 167 buf[M41T80_REG_MON] = 168 BIN2BCD(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); 169 /* assume 20YY not 19YY */ 170 buf[M41T80_REG_YEAR] = BIN2BCD(tm->tm_year % 100); 171 172 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 173 dev_err(&client->dev, "write error\n"); 174 return -EIO; 175 } 176 return 0; 177 } 178 179 #if defined(CONFIG_RTC_INTF_PROC) || defined(CONFIG_RTC_INTF_PROC_MODULE) 180 static int m41t80_rtc_proc(struct device *dev, struct seq_file *seq) 181 { 182 struct i2c_client *client = to_i2c_client(dev); 183 struct m41t80_data *clientdata = i2c_get_clientdata(client); 184 u8 reg; 185 186 if (clientdata->features & M41T80_FEATURE_BL) { 187 reg = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 188 seq_printf(seq, "battery\t\t: %s\n", 189 (reg & M41T80_FLAGS_BATT_LOW) ? "exhausted" : "ok"); 190 } 191 return 0; 192 } 193 #else 194 #define m41t80_rtc_proc NULL 195 #endif 196 197 static int m41t80_rtc_read_time(struct device *dev, struct rtc_time *tm) 198 { 199 return m41t80_get_datetime(to_i2c_client(dev), tm); 200 } 201 202 static int m41t80_rtc_set_time(struct device *dev, struct rtc_time *tm) 203 { 204 return m41t80_set_datetime(to_i2c_client(dev), tm); 205 } 206 207 #if defined(CONFIG_RTC_INTF_DEV) || defined(CONFIG_RTC_INTF_DEV_MODULE) 208 static int 209 m41t80_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 210 { 211 struct i2c_client *client = to_i2c_client(dev); 212 int rc; 213 214 switch (cmd) { 215 case RTC_AIE_OFF: 216 case RTC_AIE_ON: 217 break; 218 default: 219 return -ENOIOCTLCMD; 220 } 221 222 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 223 if (rc < 0) 224 goto err; 225 switch (cmd) { 226 case RTC_AIE_OFF: 227 rc &= ~M41T80_ALMON_AFE; 228 break; 229 case RTC_AIE_ON: 230 rc |= M41T80_ALMON_AFE; 231 break; 232 } 233 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, rc) < 0) 234 goto err; 235 return 0; 236 err: 237 return -EIO; 238 } 239 #else 240 #define m41t80_rtc_ioctl NULL 241 #endif 242 243 static int m41t80_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *t) 244 { 245 struct i2c_client *client = to_i2c_client(dev); 246 u8 wbuf[1 + M41T80_ALARM_REG_SIZE]; 247 u8 *buf = &wbuf[1]; 248 u8 *reg = buf - M41T80_REG_ALARM_MON; 249 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 250 struct i2c_msg msgs_in[] = { 251 { 252 .addr = client->addr, 253 .flags = 0, 254 .len = 1, 255 .buf = dt_addr, 256 }, 257 { 258 .addr = client->addr, 259 .flags = I2C_M_RD, 260 .len = M41T80_ALARM_REG_SIZE, 261 .buf = buf, 262 }, 263 }; 264 struct i2c_msg msgs[] = { 265 { 266 .addr = client->addr, 267 .flags = 0, 268 .len = 1 + M41T80_ALARM_REG_SIZE, 269 .buf = wbuf, 270 }, 271 }; 272 273 if (i2c_transfer(client->adapter, msgs_in, 2) < 0) { 274 dev_err(&client->dev, "read error\n"); 275 return -EIO; 276 } 277 reg[M41T80_REG_ALARM_MON] &= ~(0x1f | M41T80_ALMON_AFE); 278 reg[M41T80_REG_ALARM_DAY] = 0; 279 reg[M41T80_REG_ALARM_HOUR] &= ~(0x3f | 0x80); 280 reg[M41T80_REG_ALARM_MIN] = 0; 281 reg[M41T80_REG_ALARM_SEC] = 0; 282 283 wbuf[0] = M41T80_REG_ALARM_MON; /* offset into rtc's regs */ 284 reg[M41T80_REG_ALARM_SEC] |= t->time.tm_sec >= 0 ? 285 BIN2BCD(t->time.tm_sec) : 0x80; 286 reg[M41T80_REG_ALARM_MIN] |= t->time.tm_min >= 0 ? 287 BIN2BCD(t->time.tm_min) : 0x80; 288 reg[M41T80_REG_ALARM_HOUR] |= t->time.tm_hour >= 0 ? 289 BIN2BCD(t->time.tm_hour) : 0x80; 290 reg[M41T80_REG_ALARM_DAY] |= t->time.tm_mday >= 0 ? 291 BIN2BCD(t->time.tm_mday) : 0x80; 292 if (t->time.tm_mon >= 0) 293 reg[M41T80_REG_ALARM_MON] |= BIN2BCD(t->time.tm_mon + 1); 294 else 295 reg[M41T80_REG_ALARM_DAY] |= 0x40; 296 297 if (i2c_transfer(client->adapter, msgs, 1) != 1) { 298 dev_err(&client->dev, "write error\n"); 299 return -EIO; 300 } 301 302 if (t->enabled) { 303 reg[M41T80_REG_ALARM_MON] |= M41T80_ALMON_AFE; 304 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 305 reg[M41T80_REG_ALARM_MON]) < 0) { 306 dev_err(&client->dev, "write error\n"); 307 return -EIO; 308 } 309 } 310 return 0; 311 } 312 313 static int m41t80_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *t) 314 { 315 struct i2c_client *client = to_i2c_client(dev); 316 u8 buf[M41T80_ALARM_REG_SIZE + 1]; /* all alarm regs and flags */ 317 u8 dt_addr[1] = { M41T80_REG_ALARM_MON }; 318 u8 *reg = buf - M41T80_REG_ALARM_MON; 319 struct i2c_msg msgs[] = { 320 { 321 .addr = client->addr, 322 .flags = 0, 323 .len = 1, 324 .buf = dt_addr, 325 }, 326 { 327 .addr = client->addr, 328 .flags = I2C_M_RD, 329 .len = M41T80_ALARM_REG_SIZE + 1, 330 .buf = buf, 331 }, 332 }; 333 334 if (i2c_transfer(client->adapter, msgs, 2) < 0) { 335 dev_err(&client->dev, "read error\n"); 336 return -EIO; 337 } 338 t->time.tm_sec = -1; 339 t->time.tm_min = -1; 340 t->time.tm_hour = -1; 341 t->time.tm_mday = -1; 342 t->time.tm_mon = -1; 343 if (!(reg[M41T80_REG_ALARM_SEC] & 0x80)) 344 t->time.tm_sec = BCD2BIN(reg[M41T80_REG_ALARM_SEC] & 0x7f); 345 if (!(reg[M41T80_REG_ALARM_MIN] & 0x80)) 346 t->time.tm_min = BCD2BIN(reg[M41T80_REG_ALARM_MIN] & 0x7f); 347 if (!(reg[M41T80_REG_ALARM_HOUR] & 0x80)) 348 t->time.tm_hour = BCD2BIN(reg[M41T80_REG_ALARM_HOUR] & 0x3f); 349 if (!(reg[M41T80_REG_ALARM_DAY] & 0x80)) 350 t->time.tm_mday = BCD2BIN(reg[M41T80_REG_ALARM_DAY] & 0x3f); 351 if (!(reg[M41T80_REG_ALARM_DAY] & 0x40)) 352 t->time.tm_mon = BCD2BIN(reg[M41T80_REG_ALARM_MON] & 0x1f) - 1; 353 t->time.tm_year = -1; 354 t->time.tm_wday = -1; 355 t->time.tm_yday = -1; 356 t->time.tm_isdst = -1; 357 t->enabled = !!(reg[M41T80_REG_ALARM_MON] & M41T80_ALMON_AFE); 358 t->pending = !!(reg[M41T80_REG_FLAGS] & M41T80_FLAGS_AF); 359 return 0; 360 } 361 362 static struct rtc_class_ops m41t80_rtc_ops = { 363 .read_time = m41t80_rtc_read_time, 364 .set_time = m41t80_rtc_set_time, 365 .read_alarm = m41t80_rtc_read_alarm, 366 .set_alarm = m41t80_rtc_set_alarm, 367 .proc = m41t80_rtc_proc, 368 .ioctl = m41t80_rtc_ioctl, 369 }; 370 371 #if defined(CONFIG_RTC_INTF_SYSFS) || defined(CONFIG_RTC_INTF_SYSFS_MODULE) 372 static ssize_t m41t80_sysfs_show_flags(struct device *dev, 373 struct device_attribute *attr, char *buf) 374 { 375 struct i2c_client *client = to_i2c_client(dev); 376 int val; 377 378 val = i2c_smbus_read_byte_data(client, M41T80_REG_FLAGS); 379 if (val < 0) 380 return -EIO; 381 return sprintf(buf, "%#x\n", val); 382 } 383 static DEVICE_ATTR(flags, S_IRUGO, m41t80_sysfs_show_flags, NULL); 384 385 static ssize_t m41t80_sysfs_show_sqwfreq(struct device *dev, 386 struct device_attribute *attr, char *buf) 387 { 388 struct i2c_client *client = to_i2c_client(dev); 389 int val; 390 391 val = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 392 if (val < 0) 393 return -EIO; 394 val = (val >> 4) & 0xf; 395 switch (val) { 396 case 0: 397 break; 398 case 1: 399 val = 32768; 400 break; 401 default: 402 val = 32768 >> val; 403 } 404 return sprintf(buf, "%d\n", val); 405 } 406 static ssize_t m41t80_sysfs_set_sqwfreq(struct device *dev, 407 struct device_attribute *attr, 408 const char *buf, size_t count) 409 { 410 struct i2c_client *client = to_i2c_client(dev); 411 int almon, sqw; 412 int val = simple_strtoul(buf, NULL, 0); 413 414 if (val) { 415 if (!is_power_of_2(val)) 416 return -EINVAL; 417 val = ilog2(val); 418 if (val == 15) 419 val = 1; 420 else if (val < 14) 421 val = 15 - val; 422 else 423 return -EINVAL; 424 } 425 /* disable SQW, set SQW frequency & re-enable */ 426 almon = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_MON); 427 if (almon < 0) 428 return -EIO; 429 sqw = i2c_smbus_read_byte_data(client, M41T80_REG_SQW); 430 if (sqw < 0) 431 return -EIO; 432 sqw = (sqw & 0x0f) | (val << 4); 433 if (i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 434 almon & ~M41T80_ALMON_SQWE) < 0 || 435 i2c_smbus_write_byte_data(client, M41T80_REG_SQW, sqw) < 0) 436 return -EIO; 437 if (val && i2c_smbus_write_byte_data(client, M41T80_REG_ALARM_MON, 438 almon | M41T80_ALMON_SQWE) < 0) 439 return -EIO; 440 return count; 441 } 442 static DEVICE_ATTR(sqwfreq, S_IRUGO | S_IWUSR, 443 m41t80_sysfs_show_sqwfreq, m41t80_sysfs_set_sqwfreq); 444 445 static struct attribute *attrs[] = { 446 &dev_attr_flags.attr, 447 &dev_attr_sqwfreq.attr, 448 NULL, 449 }; 450 static struct attribute_group attr_group = { 451 .attrs = attrs, 452 }; 453 454 static int m41t80_sysfs_register(struct device *dev) 455 { 456 return sysfs_create_group(&dev->kobj, &attr_group); 457 } 458 #else 459 static int m41t80_sysfs_register(struct device *dev) 460 { 461 return 0; 462 } 463 #endif 464 465 #ifdef CONFIG_RTC_DRV_M41T80_WDT 466 /* 467 ***************************************************************************** 468 * 469 * Watchdog Driver 470 * 471 ***************************************************************************** 472 */ 473 static struct i2c_client *save_client; 474 475 /* Default margin */ 476 #define WD_TIMO 60 /* 1..31 seconds */ 477 478 static int wdt_margin = WD_TIMO; 479 module_param(wdt_margin, int, 0); 480 MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 60s)"); 481 482 static unsigned long wdt_is_open; 483 static int boot_flag; 484 485 /** 486 * wdt_ping: 487 * 488 * Reload counter one with the watchdog timeout. We don't bother reloading 489 * the cascade counter. 490 */ 491 static void wdt_ping(void) 492 { 493 unsigned char i2c_data[2]; 494 struct i2c_msg msgs1[1] = { 495 { 496 .addr = save_client->addr, 497 .flags = 0, 498 .len = 2, 499 .buf = i2c_data, 500 }, 501 }; 502 i2c_data[0] = 0x09; /* watchdog register */ 503 504 if (wdt_margin > 31) 505 i2c_data[1] = (wdt_margin & 0xFC) | 0x83; /* resolution = 4s */ 506 else 507 /* 508 * WDS = 1 (0x80), mulitplier = WD_TIMO, resolution = 1s (0x02) 509 */ 510 i2c_data[1] = wdt_margin<<2 | 0x82; 511 512 i2c_transfer(save_client->adapter, msgs1, 1); 513 } 514 515 /** 516 * wdt_disable: 517 * 518 * disables watchdog. 519 */ 520 static void wdt_disable(void) 521 { 522 unsigned char i2c_data[2], i2c_buf[0x10]; 523 struct i2c_msg msgs0[2] = { 524 { 525 .addr = save_client->addr, 526 .flags = 0, 527 .len = 1, 528 .buf = i2c_data, 529 }, 530 { 531 .addr = save_client->addr, 532 .flags = I2C_M_RD, 533 .len = 1, 534 .buf = i2c_buf, 535 }, 536 }; 537 struct i2c_msg msgs1[1] = { 538 { 539 .addr = save_client->addr, 540 .flags = 0, 541 .len = 2, 542 .buf = i2c_data, 543 }, 544 }; 545 546 i2c_data[0] = 0x09; 547 i2c_transfer(save_client->adapter, msgs0, 2); 548 549 i2c_data[0] = 0x09; 550 i2c_data[1] = 0x00; 551 i2c_transfer(save_client->adapter, msgs1, 1); 552 } 553 554 /** 555 * wdt_write: 556 * @file: file handle to the watchdog 557 * @buf: buffer to write (unused as data does not matter here 558 * @count: count of bytes 559 * @ppos: pointer to the position to write. No seeks allowed 560 * 561 * A write to a watchdog device is defined as a keepalive signal. Any 562 * write of data will do, as we we don't define content meaning. 563 */ 564 static ssize_t wdt_write(struct file *file, const char __user *buf, 565 size_t count, loff_t *ppos) 566 { 567 /* Can't seek (pwrite) on this device 568 if (ppos != &file->f_pos) 569 return -ESPIPE; 570 */ 571 if (count) { 572 wdt_ping(); 573 return 1; 574 } 575 return 0; 576 } 577 578 static ssize_t wdt_read(struct file *file, char __user *buf, 579 size_t count, loff_t *ppos) 580 { 581 return 0; 582 } 583 584 /** 585 * wdt_ioctl: 586 * @inode: inode of the device 587 * @file: file handle to the device 588 * @cmd: watchdog command 589 * @arg: argument pointer 590 * 591 * The watchdog API defines a common set of functions for all watchdogs 592 * according to their available features. We only actually usefully support 593 * querying capabilities and current status. 594 */ 595 static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, 596 unsigned long arg) 597 { 598 int new_margin, rv; 599 static struct watchdog_info ident = { 600 .options = WDIOF_POWERUNDER | WDIOF_KEEPALIVEPING | 601 WDIOF_SETTIMEOUT, 602 .firmware_version = 1, 603 .identity = "M41T80 WTD" 604 }; 605 606 switch (cmd) { 607 case WDIOC_GETSUPPORT: 608 return copy_to_user((struct watchdog_info __user *)arg, &ident, 609 sizeof(ident)) ? -EFAULT : 0; 610 611 case WDIOC_GETSTATUS: 612 case WDIOC_GETBOOTSTATUS: 613 return put_user(boot_flag, (int __user *)arg); 614 case WDIOC_KEEPALIVE: 615 wdt_ping(); 616 return 0; 617 case WDIOC_SETTIMEOUT: 618 if (get_user(new_margin, (int __user *)arg)) 619 return -EFAULT; 620 /* Arbitrary, can't find the card's limits */ 621 if (new_margin < 1 || new_margin > 124) 622 return -EINVAL; 623 wdt_margin = new_margin; 624 wdt_ping(); 625 /* Fall */ 626 case WDIOC_GETTIMEOUT: 627 return put_user(wdt_margin, (int __user *)arg); 628 629 case WDIOC_SETOPTIONS: 630 if (copy_from_user(&rv, (int __user *)arg, sizeof(int))) 631 return -EFAULT; 632 633 if (rv & WDIOS_DISABLECARD) { 634 pr_info("rtc-m41t80: disable watchdog\n"); 635 wdt_disable(); 636 } 637 638 if (rv & WDIOS_ENABLECARD) { 639 pr_info("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 lock_kernel(); 658 if (test_and_set_bit(0, &wdt_is_open)) { 659 unlock_kernel(); 660 return -EBUSY; 661 } 662 /* 663 * Activate 664 */ 665 wdt_is_open = 1; 666 unlock_kernel(); 667 return 0; 668 } 669 return -ENODEV; 670 } 671 672 /** 673 * wdt_close: 674 * @inode: inode to board 675 * @file: file handle to board 676 * 677 */ 678 static int wdt_release(struct inode *inode, struct file *file) 679 { 680 if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) 681 clear_bit(0, &wdt_is_open); 682 return 0; 683 } 684 685 /** 686 * notify_sys: 687 * @this: our notifier block 688 * @code: the event being reported 689 * @unused: unused 690 * 691 * Our notifier is called on system shutdowns. We want to turn the card 692 * off at reboot otherwise the machine will reboot again during memory 693 * test or worse yet during the following fsck. This would suck, in fact 694 * trust me - if it happens it does suck. 695 */ 696 static int wdt_notify_sys(struct notifier_block *this, unsigned long code, 697 void *unused) 698 { 699 if (code == SYS_DOWN || code == SYS_HALT) 700 /* Disable Watchdog */ 701 wdt_disable(); 702 return NOTIFY_DONE; 703 } 704 705 static const struct file_operations wdt_fops = { 706 .owner = THIS_MODULE, 707 .read = wdt_read, 708 .ioctl = wdt_ioctl, 709 .write = wdt_write, 710 .open = wdt_open, 711 .release = wdt_release, 712 }; 713 714 static struct miscdevice wdt_dev = { 715 .minor = WATCHDOG_MINOR, 716 .name = "watchdog", 717 .fops = &wdt_fops, 718 }; 719 720 /* 721 * The WDT card needs to learn about soft shutdowns in order to 722 * turn the timebomb registers off. 723 */ 724 static struct notifier_block wdt_notifier = { 725 .notifier_call = wdt_notify_sys, 726 }; 727 #endif /* CONFIG_RTC_DRV_M41T80_WDT */ 728 729 /* 730 ***************************************************************************** 731 * 732 * Driver Interface 733 * 734 ***************************************************************************** 735 */ 736 static int m41t80_probe(struct i2c_client *client, 737 const struct i2c_device_id *id) 738 { 739 int rc = 0; 740 struct rtc_device *rtc = NULL; 741 struct rtc_time tm; 742 struct m41t80_data *clientdata = NULL; 743 744 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C 745 | I2C_FUNC_SMBUS_BYTE_DATA)) { 746 rc = -ENODEV; 747 goto exit; 748 } 749 750 dev_info(&client->dev, 751 "chip found, driver version " DRV_VERSION "\n"); 752 753 clientdata = kzalloc(sizeof(*clientdata), GFP_KERNEL); 754 if (!clientdata) { 755 rc = -ENOMEM; 756 goto exit; 757 } 758 759 rtc = rtc_device_register(client->name, &client->dev, 760 &m41t80_rtc_ops, THIS_MODULE); 761 if (IS_ERR(rtc)) { 762 rc = PTR_ERR(rtc); 763 rtc = NULL; 764 goto exit; 765 } 766 767 clientdata->rtc = rtc; 768 clientdata->features = id->driver_data; 769 i2c_set_clientdata(client, clientdata); 770 771 /* Make sure HT (Halt Update) bit is cleared */ 772 rc = i2c_smbus_read_byte_data(client, M41T80_REG_ALARM_HOUR); 773 if (rc < 0) 774 goto ht_err; 775 776 if (rc & M41T80_ALHOUR_HT) { 777 if (clientdata->features & M41T80_FEATURE_HT) { 778 m41t80_get_datetime(client, &tm); 779 dev_info(&client->dev, "HT bit was set!\n"); 780 dev_info(&client->dev, 781 "Power Down at " 782 "%04i-%02i-%02i %02i:%02i:%02i\n", 783 tm.tm_year + 1900, 784 tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, 785 tm.tm_min, tm.tm_sec); 786 } 787 if (i2c_smbus_write_byte_data(client, 788 M41T80_REG_ALARM_HOUR, 789 rc & ~M41T80_ALHOUR_HT) < 0) 790 goto ht_err; 791 } 792 793 /* Make sure ST (stop) bit is cleared */ 794 rc = i2c_smbus_read_byte_data(client, M41T80_REG_SEC); 795 if (rc < 0) 796 goto st_err; 797 798 if (rc & M41T80_SEC_ST) { 799 if (i2c_smbus_write_byte_data(client, M41T80_REG_SEC, 800 rc & ~M41T80_SEC_ST) < 0) 801 goto st_err; 802 } 803 804 rc = m41t80_sysfs_register(&client->dev); 805 if (rc) 806 goto exit; 807 808 #ifdef CONFIG_RTC_DRV_M41T80_WDT 809 if (clientdata->features & M41T80_FEATURE_HT) { 810 save_client = client; 811 rc = misc_register(&wdt_dev); 812 if (rc) 813 goto exit; 814 rc = register_reboot_notifier(&wdt_notifier); 815 if (rc) { 816 misc_deregister(&wdt_dev); 817 goto exit; 818 } 819 } 820 #endif 821 return 0; 822 823 st_err: 824 rc = -EIO; 825 dev_err(&client->dev, "Can't clear ST bit\n"); 826 goto exit; 827 ht_err: 828 rc = -EIO; 829 dev_err(&client->dev, "Can't clear HT bit\n"); 830 goto exit; 831 832 exit: 833 if (rtc) 834 rtc_device_unregister(rtc); 835 kfree(clientdata); 836 return rc; 837 } 838 839 static int m41t80_remove(struct i2c_client *client) 840 { 841 struct m41t80_data *clientdata = i2c_get_clientdata(client); 842 struct rtc_device *rtc = clientdata->rtc; 843 844 #ifdef CONFIG_RTC_DRV_M41T80_WDT 845 if (clientdata->features & M41T80_FEATURE_HT) { 846 misc_deregister(&wdt_dev); 847 unregister_reboot_notifier(&wdt_notifier); 848 } 849 #endif 850 if (rtc) 851 rtc_device_unregister(rtc); 852 kfree(clientdata); 853 854 return 0; 855 } 856 857 static struct i2c_driver m41t80_driver = { 858 .driver = { 859 .name = "rtc-m41t80", 860 }, 861 .probe = m41t80_probe, 862 .remove = m41t80_remove, 863 .id_table = m41t80_id, 864 }; 865 866 static int __init m41t80_rtc_init(void) 867 { 868 return i2c_add_driver(&m41t80_driver); 869 } 870 871 static void __exit m41t80_rtc_exit(void) 872 { 873 i2c_del_driver(&m41t80_driver); 874 } 875 876 MODULE_AUTHOR("Alexander Bigga <ab@mycable.de>"); 877 MODULE_DESCRIPTION("ST Microelectronics M41T80 series RTC I2C Client Driver"); 878 MODULE_LICENSE("GPL"); 879 MODULE_VERSION(DRV_VERSION); 880 881 module_init(m41t80_rtc_init); 882 module_exit(m41t80_rtc_exit); 883