Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 | /* * Copyright (C) ST-Ericsson SA 2010 * * License terms: GNU General Public License (GPL) version 2 * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com> * * RTC clock driver for the RTC part of the AB8500 Power management chip. * Based on RTC clock driver for the AB3100 Analog Baseband Chip by * Linus Walleij <linus.walleij@stericsson.com> */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/platform_device.h> #include <linux/rtc.h> #include <linux/mfd/abx500.h> #include <linux/mfd/abx500/ab8500.h> #include <linux/delay.h> #include <linux/of.h> #define AB8500_RTC_SOFF_STAT_REG 0x00 #define AB8500_RTC_CC_CONF_REG 0x01 #define AB8500_RTC_READ_REQ_REG 0x02 #define AB8500_RTC_WATCH_TSECMID_REG 0x03 #define AB8500_RTC_WATCH_TSECHI_REG 0x04 #define AB8500_RTC_WATCH_TMIN_LOW_REG 0x05 #define AB8500_RTC_WATCH_TMIN_MID_REG 0x06 #define AB8500_RTC_WATCH_TMIN_HI_REG 0x07 #define AB8500_RTC_ALRM_MIN_LOW_REG 0x08 #define AB8500_RTC_ALRM_MIN_MID_REG 0x09 #define AB8500_RTC_ALRM_MIN_HI_REG 0x0A #define AB8500_RTC_STAT_REG 0x0B #define AB8500_RTC_BKUP_CHG_REG 0x0C #define AB8500_RTC_FORCE_BKUP_REG 0x0D #define AB8500_RTC_CALIB_REG 0x0E #define AB8500_RTC_SWITCH_STAT_REG 0x0F #define AB8540_RTC_ALRM_SEC 0x22 #define AB8540_RTC_ALRM_MIN_LOW_REG 0x23 #define AB8540_RTC_ALRM_MIN_MID_REG 0x24 #define AB8540_RTC_ALRM_MIN_HI_REG 0x25 /* RtcReadRequest bits */ #define RTC_READ_REQUEST 0x01 #define RTC_WRITE_REQUEST 0x02 /* RtcCtrl bits */ #define RTC_ALARM_ENA 0x04 #define RTC_STATUS_DATA 0x01 #define COUNTS_PER_SEC (0xF000 / 60) #define AB8500_RTC_EPOCH 2000 static const u8 ab8500_rtc_time_regs[] = { AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG, AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG, AB8500_RTC_WATCH_TSECMID_REG }; static const u8 ab8500_rtc_alarm_regs[] = { AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG, AB8500_RTC_ALRM_MIN_LOW_REG }; static const u8 ab8540_rtc_alarm_regs[] = { AB8540_RTC_ALRM_MIN_HI_REG, AB8540_RTC_ALRM_MIN_MID_REG, AB8540_RTC_ALRM_MIN_LOW_REG, AB8540_RTC_ALRM_SEC }; /* Calculate the seconds from 1970 to 01-01-2000 00:00:00 */ static unsigned long get_elapsed_seconds(int year) { unsigned long secs; struct rtc_time tm = { .tm_year = year - 1900, .tm_mday = 1, }; /* * This function calculates secs from 1970 and not from * 1900, even if we supply the offset from year 1900. */ rtc_tm_to_time(&tm, &secs); return secs; } static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm) { unsigned long timeout = jiffies + HZ; int retval, i; unsigned long mins, secs; unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)]; u8 value; /* Request a data read */ retval = abx500_set_register_interruptible(dev, AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST); if (retval < 0) return retval; /* Wait for some cycles after enabling the rtc read in ab8500 */ while (time_before(jiffies, timeout)) { retval = abx500_get_register_interruptible(dev, AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value); if (retval < 0) return retval; if (!(value & RTC_READ_REQUEST)) break; usleep_range(1000, 5000); } /* Read the Watchtime registers */ for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) { retval = abx500_get_register_interruptible(dev, AB8500_RTC, ab8500_rtc_time_regs[i], &value); if (retval < 0) return retval; buf[i] = value; } mins = (buf[0] << 16) | (buf[1] << 8) | buf[2]; secs = (buf[3] << 8) | buf[4]; secs = secs / COUNTS_PER_SEC; secs = secs + (mins * 60); /* Add back the initially subtracted number of seconds */ secs += get_elapsed_seconds(AB8500_RTC_EPOCH); rtc_time_to_tm(secs, tm); return rtc_valid_tm(tm); } static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm) { int retval, i; unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)]; unsigned long no_secs, no_mins, secs = 0; if (tm->tm_year < (AB8500_RTC_EPOCH - 1900)) { dev_dbg(dev, "year should be equal to or greater than %d\n", AB8500_RTC_EPOCH); return -EINVAL; } /* Get the number of seconds since 1970 */ rtc_tm_to_time(tm, &secs); /* * Convert it to the number of seconds since 01-01-2000 00:00:00, since * we only have a small counter in the RTC. */ secs -= get_elapsed_seconds(AB8500_RTC_EPOCH); no_mins = secs / 60; no_secs = secs % 60; /* Make the seconds count as per the RTC resolution */ no_secs = no_secs * COUNTS_PER_SEC; buf[4] = no_secs & 0xFF; buf[3] = (no_secs >> 8) & 0xFF; buf[2] = no_mins & 0xFF; buf[1] = (no_mins >> 8) & 0xFF; buf[0] = (no_mins >> 16) & 0xFF; for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) { retval = abx500_set_register_interruptible(dev, AB8500_RTC, ab8500_rtc_time_regs[i], buf[i]); if (retval < 0) return retval; } /* Request a data write */ return abx500_set_register_interruptible(dev, AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST); } static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { int retval, i; u8 rtc_ctrl, value; unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)]; unsigned long secs, mins; /* Check if the alarm is enabled or not */ retval = abx500_get_register_interruptible(dev, AB8500_RTC, AB8500_RTC_STAT_REG, &rtc_ctrl); if (retval < 0) return retval; if (rtc_ctrl & RTC_ALARM_ENA) alarm->enabled = 1; else alarm->enabled = 0; alarm->pending = 0; for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) { retval = abx500_get_register_interruptible(dev, AB8500_RTC, ab8500_rtc_alarm_regs[i], &value); if (retval < 0) return retval; buf[i] = value; } mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]); secs = mins * 60; /* Add back the initially subtracted number of seconds */ secs += get_elapsed_seconds(AB8500_RTC_EPOCH); rtc_time_to_tm(secs, &alarm->time); return rtc_valid_tm(&alarm->time); } static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled) { return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC, AB8500_RTC_STAT_REG, RTC_ALARM_ENA, enabled ? RTC_ALARM_ENA : 0); } static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { int retval, i; unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)]; unsigned long mins, secs = 0, cursec = 0; struct rtc_time curtm; if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) { dev_dbg(dev, "year should be equal to or greater than %d\n", AB8500_RTC_EPOCH); return -EINVAL; } /* Get the number of seconds since 1970 */ rtc_tm_to_time(&alarm->time, &secs); /* * Check whether alarm is set less than 1min. * Since our RTC doesn't support alarm resolution less than 1min, * return -EINVAL, so UIE EMUL can take it up, incase of UIE_ON */ ab8500_rtc_read_time(dev, &curtm); /* Read current time */ rtc_tm_to_time(&curtm, &cursec); if ((secs - cursec) < 59) { dev_dbg(dev, "Alarm less than 1 minute not supported\r\n"); return -EINVAL; } /* * Convert it to the number of seconds since 01-01-2000 00:00:00, since * we only have a small counter in the RTC. */ secs -= get_elapsed_seconds(AB8500_RTC_EPOCH); mins = secs / 60; buf[2] = mins & 0xFF; buf[1] = (mins >> 8) & 0xFF; buf[0] = (mins >> 16) & 0xFF; /* Set the alarm time */ for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) { retval = abx500_set_register_interruptible(dev, AB8500_RTC, ab8500_rtc_alarm_regs[i], buf[i]); if (retval < 0) return retval; } return ab8500_rtc_irq_enable(dev, alarm->enabled); } static int ab8540_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { int retval, i; unsigned char buf[ARRAY_SIZE(ab8540_rtc_alarm_regs)]; unsigned long mins, secs = 0; if (alarm->time.tm_year < (AB8500_RTC_EPOCH - 1900)) { dev_dbg(dev, "year should be equal to or greater than %d\n", AB8500_RTC_EPOCH); return -EINVAL; } /* Get the number of seconds since 1970 */ rtc_tm_to_time(&alarm->time, &secs); /* * Convert it to the number of seconds since 01-01-2000 00:00:00 */ secs -= get_elapsed_seconds(AB8500_RTC_EPOCH); mins = secs / 60; buf[3] = secs % 60; buf[2] = mins & 0xFF; buf[1] = (mins >> 8) & 0xFF; buf[0] = (mins >> 16) & 0xFF; /* Set the alarm time */ for (i = 0; i < ARRAY_SIZE(ab8540_rtc_alarm_regs); i++) { retval = abx500_set_register_interruptible(dev, AB8500_RTC, ab8540_rtc_alarm_regs[i], buf[i]); if (retval < 0) return retval; } return ab8500_rtc_irq_enable(dev, alarm->enabled); } static int ab8500_rtc_set_calibration(struct device *dev, int calibration) { int retval; u8 rtccal = 0; /* * Check that the calibration value (which is in units of 0.5 * parts-per-million) is in the AB8500's range for RtcCalibration * register. -128 (0x80) is not permitted because the AB8500 uses * a sign-bit rather than two's complement, so 0x80 is just another * representation of zero. */ if ((calibration < -127) || (calibration > 127)) { dev_err(dev, "RtcCalibration value outside permitted range\n"); return -EINVAL; } /* * The AB8500 uses sign (in bit7) and magnitude (in bits0-7) * so need to convert to this sort of representation before writing * into RtcCalibration register... */ if (calibration >= 0) rtccal = 0x7F & calibration; else rtccal = ~(calibration - 1) | 0x80; retval = abx500_set_register_interruptible(dev, AB8500_RTC, AB8500_RTC_CALIB_REG, rtccal); return retval; } static int ab8500_rtc_get_calibration(struct device *dev, int *calibration) { int retval; u8 rtccal = 0; retval = abx500_get_register_interruptible(dev, AB8500_RTC, AB8500_RTC_CALIB_REG, &rtccal); if (retval >= 0) { /* * The AB8500 uses sign (in bit7) and magnitude (in bits0-7) * so need to convert value from RtcCalibration register into * a two's complement signed value... */ if (rtccal & 0x80) *calibration = 0 - (rtccal & 0x7F); else *calibration = 0x7F & rtccal; } return retval; } static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { int retval; int calibration = 0; if (sscanf(buf, " %i ", &calibration) != 1) { dev_err(dev, "Failed to store RTC calibration attribute\n"); return -EINVAL; } retval = ab8500_rtc_set_calibration(dev, calibration); return retval ? retval : count; } static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev, struct device_attribute *attr, char *buf) { int retval = 0; int calibration = 0; retval = ab8500_rtc_get_calibration(dev, &calibration); if (retval < 0) { dev_err(dev, "Failed to read RTC calibration attribute\n"); sprintf(buf, "0\n"); return retval; } return sprintf(buf, "%d\n", calibration); } static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR, ab8500_sysfs_show_rtc_calibration, ab8500_sysfs_store_rtc_calibration); static int ab8500_sysfs_rtc_register(struct device *dev) { return device_create_file(dev, &dev_attr_rtc_calibration); } static void ab8500_sysfs_rtc_unregister(struct device *dev) { device_remove_file(dev, &dev_attr_rtc_calibration); } static irqreturn_t rtc_alarm_handler(int irq, void *data) { struct rtc_device *rtc = data; unsigned long events = RTC_IRQF | RTC_AF; dev_dbg(&rtc->dev, "%s\n", __func__); rtc_update_irq(rtc, 1, events); return IRQ_HANDLED; } static const struct rtc_class_ops ab8500_rtc_ops = { .read_time = ab8500_rtc_read_time, .set_time = ab8500_rtc_set_time, .read_alarm = ab8500_rtc_read_alarm, .set_alarm = ab8500_rtc_set_alarm, .alarm_irq_enable = ab8500_rtc_irq_enable, }; static const struct rtc_class_ops ab8540_rtc_ops = { .read_time = ab8500_rtc_read_time, .set_time = ab8500_rtc_set_time, .read_alarm = ab8500_rtc_read_alarm, .set_alarm = ab8540_rtc_set_alarm, .alarm_irq_enable = ab8500_rtc_irq_enable, }; static struct platform_device_id ab85xx_rtc_ids[] = { { "ab8500-rtc", (kernel_ulong_t)&ab8500_rtc_ops, }, { "ab8540-rtc", (kernel_ulong_t)&ab8540_rtc_ops, }, }; static int ab8500_rtc_probe(struct platform_device *pdev) { const struct platform_device_id *platid = platform_get_device_id(pdev); int err; struct rtc_device *rtc; u8 rtc_ctrl; int irq; irq = platform_get_irq_byname(pdev, "ALARM"); if (irq < 0) return irq; /* For RTC supply test */ err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC, AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA); if (err < 0) return err; /* Wait for reset by the PorRtc */ usleep_range(1000, 5000); err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC, AB8500_RTC_STAT_REG, &rtc_ctrl); if (err < 0) return err; /* Check if the RTC Supply fails */ if (!(rtc_ctrl & RTC_STATUS_DATA)) { dev_err(&pdev->dev, "RTC supply failure\n"); return -ENODEV; } device_init_wakeup(&pdev->dev, true); rtc = devm_rtc_device_register(&pdev->dev, "ab8500-rtc", (struct rtc_class_ops *)platid->driver_data, THIS_MODULE); if (IS_ERR(rtc)) { dev_err(&pdev->dev, "Registration failed\n"); err = PTR_ERR(rtc); return err; } err = devm_request_threaded_irq(&pdev->dev, irq, NULL, rtc_alarm_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT, "ab8500-rtc", rtc); if (err < 0) return err; platform_set_drvdata(pdev, rtc); err = ab8500_sysfs_rtc_register(&pdev->dev); if (err) { dev_err(&pdev->dev, "sysfs RTC failed to register\n"); return err; } return 0; } static int ab8500_rtc_remove(struct platform_device *pdev) { ab8500_sysfs_rtc_unregister(&pdev->dev); return 0; } static struct platform_driver ab8500_rtc_driver = { .driver = { .name = "ab8500-rtc", .owner = THIS_MODULE, }, .probe = ab8500_rtc_probe, .remove = ab8500_rtc_remove, .id_table = ab85xx_rtc_ids, }; module_platform_driver(ab8500_rtc_driver); MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>"); MODULE_DESCRIPTION("AB8500 RTC Driver"); MODULE_LICENSE("GPL v2"); |