1/* 2 * RTC driver for Maxim MAX8997 3 * 4 * Copyright (C) 2013 Samsung Electronics Co.Ltd 5 * 6 * based on rtc-max8998.c 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 * 13 */ 14 15#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 16 17#include <linux/slab.h> 18#include <linux/rtc.h> 19#include <linux/delay.h> 20#include <linux/mutex.h> 21#include <linux/module.h> 22#include <linux/platform_device.h> 23#include <linux/mfd/max8997-private.h> 24#include <linux/irqdomain.h> 25 26/* Module parameter for WTSR function control */ 27static int wtsr_en = 1; 28module_param(wtsr_en, int, 0444); 29MODULE_PARM_DESC(wtsr_en, "Watchdog Timeout & Software Reset (default=on)"); 30/* Module parameter for SMPL function control */ 31static int smpl_en = 1; 32module_param(smpl_en, int, 0444); 33MODULE_PARM_DESC(smpl_en, "Sudden Momentary Power Loss (default=on)"); 34 35/* RTC Control Register */ 36#define BCD_EN_SHIFT 0 37#define BCD_EN_MASK (1 << BCD_EN_SHIFT) 38#define MODEL24_SHIFT 1 39#define MODEL24_MASK (1 << MODEL24_SHIFT) 40/* RTC Update Register1 */ 41#define RTC_UDR_SHIFT 0 42#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT) 43/* WTSR and SMPL Register */ 44#define WTSRT_SHIFT 0 45#define SMPLT_SHIFT 2 46#define WTSR_EN_SHIFT 6 47#define SMPL_EN_SHIFT 7 48#define WTSRT_MASK (3 << WTSRT_SHIFT) 49#define SMPLT_MASK (3 << SMPLT_SHIFT) 50#define WTSR_EN_MASK (1 << WTSR_EN_SHIFT) 51#define SMPL_EN_MASK (1 << SMPL_EN_SHIFT) 52/* RTC Hour register */ 53#define HOUR_PM_SHIFT 6 54#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT) 55/* RTC Alarm Enable */ 56#define ALARM_ENABLE_SHIFT 7 57#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT) 58 59enum { 60 RTC_SEC = 0, 61 RTC_MIN, 62 RTC_HOUR, 63 RTC_WEEKDAY, 64 RTC_MONTH, 65 RTC_YEAR, 66 RTC_DATE, 67 RTC_NR_TIME 68}; 69 70struct max8997_rtc_info { 71 struct device *dev; 72 struct max8997_dev *max8997; 73 struct i2c_client *rtc; 74 struct rtc_device *rtc_dev; 75 struct mutex lock; 76 int virq; 77 int rtc_24hr_mode; 78}; 79 80static void max8997_rtc_data_to_tm(u8 *data, struct rtc_time *tm, 81 int rtc_24hr_mode) 82{ 83 tm->tm_sec = data[RTC_SEC] & 0x7f; 84 tm->tm_min = data[RTC_MIN] & 0x7f; 85 if (rtc_24hr_mode) 86 tm->tm_hour = data[RTC_HOUR] & 0x1f; 87 else { 88 tm->tm_hour = data[RTC_HOUR] & 0x0f; 89 if (data[RTC_HOUR] & HOUR_PM_MASK) 90 tm->tm_hour += 12; 91 } 92 93 tm->tm_wday = fls(data[RTC_WEEKDAY] & 0x7f) - 1; 94 tm->tm_mday = data[RTC_DATE] & 0x1f; 95 tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1; 96 tm->tm_year = (data[RTC_YEAR] & 0x7f) + 100; 97 tm->tm_yday = 0; 98 tm->tm_isdst = 0; 99} 100 101static int max8997_rtc_tm_to_data(struct rtc_time *tm, u8 *data) 102{ 103 data[RTC_SEC] = tm->tm_sec; 104 data[RTC_MIN] = tm->tm_min; 105 data[RTC_HOUR] = tm->tm_hour; 106 data[RTC_WEEKDAY] = 1 << tm->tm_wday; 107 data[RTC_DATE] = tm->tm_mday; 108 data[RTC_MONTH] = tm->tm_mon + 1; 109 data[RTC_YEAR] = tm->tm_year > 100 ? (tm->tm_year - 100) : 0; 110 111 if (tm->tm_year < 100) { 112 pr_warn("RTC cannot handle the year %d. Assume it's 2000.\n", 113 1900 + tm->tm_year); 114 return -EINVAL; 115 } 116 return 0; 117} 118 119static inline int max8997_rtc_set_update_reg(struct max8997_rtc_info *info) 120{ 121 int ret; 122 123 ret = max8997_write_reg(info->rtc, MAX8997_RTC_UPDATE1, 124 RTC_UDR_MASK); 125 if (ret < 0) 126 dev_err(info->dev, "%s: fail to write update reg(%d)\n", 127 __func__, ret); 128 else { 129 /* Minimum 16ms delay required before RTC update. 130 * Otherwise, we may read and update based on out-of-date 131 * value */ 132 msleep(20); 133 } 134 135 return ret; 136} 137 138static int max8997_rtc_read_time(struct device *dev, struct rtc_time *tm) 139{ 140 struct max8997_rtc_info *info = dev_get_drvdata(dev); 141 u8 data[RTC_NR_TIME]; 142 int ret; 143 144 mutex_lock(&info->lock); 145 ret = max8997_bulk_read(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data); 146 mutex_unlock(&info->lock); 147 148 if (ret < 0) { 149 dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, 150 ret); 151 return ret; 152 } 153 154 max8997_rtc_data_to_tm(data, tm, info->rtc_24hr_mode); 155 156 return rtc_valid_tm(tm); 157} 158 159static int max8997_rtc_set_time(struct device *dev, struct rtc_time *tm) 160{ 161 struct max8997_rtc_info *info = dev_get_drvdata(dev); 162 u8 data[RTC_NR_TIME]; 163 int ret; 164 165 ret = max8997_rtc_tm_to_data(tm, data); 166 if (ret < 0) 167 return ret; 168 169 mutex_lock(&info->lock); 170 171 ret = max8997_bulk_write(info->rtc, MAX8997_RTC_SEC, RTC_NR_TIME, data); 172 if (ret < 0) { 173 dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__, 174 ret); 175 goto out; 176 } 177 178 ret = max8997_rtc_set_update_reg(info); 179out: 180 mutex_unlock(&info->lock); 181 return ret; 182} 183 184static int max8997_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 185{ 186 struct max8997_rtc_info *info = dev_get_drvdata(dev); 187 u8 data[RTC_NR_TIME]; 188 u8 val; 189 int i, ret; 190 191 mutex_lock(&info->lock); 192 193 ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 194 data); 195 if (ret < 0) { 196 dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n", 197 __func__, __LINE__, ret); 198 goto out; 199 } 200 201 max8997_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode); 202 203 alrm->enabled = 0; 204 for (i = 0; i < RTC_NR_TIME; i++) { 205 if (data[i] & ALARM_ENABLE_MASK) { 206 alrm->enabled = 1; 207 break; 208 } 209 } 210 211 alrm->pending = 0; 212 ret = max8997_read_reg(info->max8997->i2c, MAX8997_REG_STATUS1, &val); 213 if (ret < 0) { 214 dev_err(info->dev, "%s:%d fail to read status1 reg(%d)\n", 215 __func__, __LINE__, ret); 216 goto out; 217 } 218 219 if (val & (1 << 4)) /* RTCA1 */ 220 alrm->pending = 1; 221 222out: 223 mutex_unlock(&info->lock); 224 return 0; 225} 226 227static int max8997_rtc_stop_alarm(struct max8997_rtc_info *info) 228{ 229 u8 data[RTC_NR_TIME]; 230 int ret, i; 231 232 if (!mutex_is_locked(&info->lock)) 233 dev_warn(info->dev, "%s: should have mutex locked\n", __func__); 234 235 ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 236 data); 237 if (ret < 0) { 238 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", 239 __func__, ret); 240 goto out; 241 } 242 243 for (i = 0; i < RTC_NR_TIME; i++) 244 data[i] &= ~ALARM_ENABLE_MASK; 245 246 ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 247 data); 248 if (ret < 0) { 249 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", 250 __func__, ret); 251 goto out; 252 } 253 254 ret = max8997_rtc_set_update_reg(info); 255out: 256 return ret; 257} 258 259static int max8997_rtc_start_alarm(struct max8997_rtc_info *info) 260{ 261 u8 data[RTC_NR_TIME]; 262 int ret; 263 264 if (!mutex_is_locked(&info->lock)) 265 dev_warn(info->dev, "%s: should have mutex locked\n", __func__); 266 267 ret = max8997_bulk_read(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 268 data); 269 if (ret < 0) { 270 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", 271 __func__, ret); 272 goto out; 273 } 274 275 data[RTC_SEC] |= (1 << ALARM_ENABLE_SHIFT); 276 data[RTC_MIN] |= (1 << ALARM_ENABLE_SHIFT); 277 data[RTC_HOUR] |= (1 << ALARM_ENABLE_SHIFT); 278 data[RTC_WEEKDAY] &= ~ALARM_ENABLE_MASK; 279 if (data[RTC_MONTH] & 0xf) 280 data[RTC_MONTH] |= (1 << ALARM_ENABLE_SHIFT); 281 if (data[RTC_YEAR] & 0x7f) 282 data[RTC_YEAR] |= (1 << ALARM_ENABLE_SHIFT); 283 if (data[RTC_DATE] & 0x1f) 284 data[RTC_DATE] |= (1 << ALARM_ENABLE_SHIFT); 285 286 ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 287 data); 288 if (ret < 0) { 289 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", 290 __func__, ret); 291 goto out; 292 } 293 294 ret = max8997_rtc_set_update_reg(info); 295out: 296 return ret; 297} 298static int max8997_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 299{ 300 struct max8997_rtc_info *info = dev_get_drvdata(dev); 301 u8 data[RTC_NR_TIME]; 302 int ret; 303 304 ret = max8997_rtc_tm_to_data(&alrm->time, data); 305 if (ret < 0) 306 return ret; 307 308 dev_info(info->dev, "%s: %d-%02d-%02d %02d:%02d:%02d\n", __func__, 309 data[RTC_YEAR] + 2000, data[RTC_MONTH], data[RTC_DATE], 310 data[RTC_HOUR], data[RTC_MIN], data[RTC_SEC]); 311 312 mutex_lock(&info->lock); 313 314 ret = max8997_rtc_stop_alarm(info); 315 if (ret < 0) 316 goto out; 317 318 ret = max8997_bulk_write(info->rtc, MAX8997_RTC_ALARM1_SEC, RTC_NR_TIME, 319 data); 320 if (ret < 0) { 321 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", 322 __func__, ret); 323 goto out; 324 } 325 326 ret = max8997_rtc_set_update_reg(info); 327 if (ret < 0) 328 goto out; 329 330 if (alrm->enabled) 331 ret = max8997_rtc_start_alarm(info); 332out: 333 mutex_unlock(&info->lock); 334 return ret; 335} 336 337static int max8997_rtc_alarm_irq_enable(struct device *dev, 338 unsigned int enabled) 339{ 340 struct max8997_rtc_info *info = dev_get_drvdata(dev); 341 int ret; 342 343 mutex_lock(&info->lock); 344 if (enabled) 345 ret = max8997_rtc_start_alarm(info); 346 else 347 ret = max8997_rtc_stop_alarm(info); 348 mutex_unlock(&info->lock); 349 350 return ret; 351} 352 353static irqreturn_t max8997_rtc_alarm_irq(int irq, void *data) 354{ 355 struct max8997_rtc_info *info = data; 356 357 dev_info(info->dev, "%s:irq(%d)\n", __func__, irq); 358 359 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 360 361 return IRQ_HANDLED; 362} 363 364static const struct rtc_class_ops max8997_rtc_ops = { 365 .read_time = max8997_rtc_read_time, 366 .set_time = max8997_rtc_set_time, 367 .read_alarm = max8997_rtc_read_alarm, 368 .set_alarm = max8997_rtc_set_alarm, 369 .alarm_irq_enable = max8997_rtc_alarm_irq_enable, 370}; 371 372static void max8997_rtc_enable_wtsr(struct max8997_rtc_info *info, bool enable) 373{ 374 int ret; 375 u8 val, mask; 376 377 if (!wtsr_en) 378 return; 379 380 if (enable) 381 val = (1 << WTSR_EN_SHIFT) | (3 << WTSRT_SHIFT); 382 else 383 val = 0; 384 385 mask = WTSR_EN_MASK | WTSRT_MASK; 386 387 dev_info(info->dev, "%s: %s WTSR\n", __func__, 388 enable ? "enable" : "disable"); 389 390 ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask); 391 if (ret < 0) { 392 dev_err(info->dev, "%s: fail to update WTSR reg(%d)\n", 393 __func__, ret); 394 return; 395 } 396 397 max8997_rtc_set_update_reg(info); 398} 399 400static void max8997_rtc_enable_smpl(struct max8997_rtc_info *info, bool enable) 401{ 402 int ret; 403 u8 val, mask; 404 405 if (!smpl_en) 406 return; 407 408 if (enable) 409 val = (1 << SMPL_EN_SHIFT) | (0 << SMPLT_SHIFT); 410 else 411 val = 0; 412 413 mask = SMPL_EN_MASK | SMPLT_MASK; 414 415 dev_info(info->dev, "%s: %s SMPL\n", __func__, 416 enable ? "enable" : "disable"); 417 418 ret = max8997_update_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, val, mask); 419 if (ret < 0) { 420 dev_err(info->dev, "%s: fail to update SMPL reg(%d)\n", 421 __func__, ret); 422 return; 423 } 424 425 max8997_rtc_set_update_reg(info); 426 427 val = 0; 428 max8997_read_reg(info->rtc, MAX8997_RTC_WTSR_SMPL, &val); 429 pr_info("WTSR_SMPL(0x%02x)\n", val); 430} 431 432static int max8997_rtc_init_reg(struct max8997_rtc_info *info) 433{ 434 u8 data[2]; 435 int ret; 436 437 /* Set RTC control register : Binary mode, 24hour mdoe */ 438 data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); 439 data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); 440 441 info->rtc_24hr_mode = 1; 442 443 ret = max8997_bulk_write(info->rtc, MAX8997_RTC_CTRLMASK, 2, data); 444 if (ret < 0) { 445 dev_err(info->dev, "%s: fail to write controlm reg(%d)\n", 446 __func__, ret); 447 return ret; 448 } 449 450 ret = max8997_rtc_set_update_reg(info); 451 return ret; 452} 453 454static int max8997_rtc_probe(struct platform_device *pdev) 455{ 456 struct max8997_dev *max8997 = dev_get_drvdata(pdev->dev.parent); 457 struct max8997_rtc_info *info; 458 int ret, virq; 459 460 info = devm_kzalloc(&pdev->dev, sizeof(struct max8997_rtc_info), 461 GFP_KERNEL); 462 if (!info) 463 return -ENOMEM; 464 465 mutex_init(&info->lock); 466 info->dev = &pdev->dev; 467 info->max8997 = max8997; 468 info->rtc = max8997->rtc; 469 470 platform_set_drvdata(pdev, info); 471 472 ret = max8997_rtc_init_reg(info); 473 474 if (ret < 0) { 475 dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret); 476 return ret; 477 } 478 479 max8997_rtc_enable_wtsr(info, true); 480 max8997_rtc_enable_smpl(info, true); 481 482 device_init_wakeup(&pdev->dev, 1); 483 484 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8997-rtc", 485 &max8997_rtc_ops, THIS_MODULE); 486 487 if (IS_ERR(info->rtc_dev)) { 488 ret = PTR_ERR(info->rtc_dev); 489 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 490 return ret; 491 } 492 493 virq = irq_create_mapping(max8997->irq_domain, MAX8997_PMICIRQ_RTCA1); 494 if (!virq) { 495 dev_err(&pdev->dev, "Failed to create mapping alarm IRQ\n"); 496 ret = -ENXIO; 497 goto err_out; 498 } 499 info->virq = virq; 500 501 ret = devm_request_threaded_irq(&pdev->dev, virq, NULL, 502 max8997_rtc_alarm_irq, 0, 503 "rtc-alarm0", info); 504 if (ret < 0) 505 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", 506 info->virq, ret); 507 508err_out: 509 return ret; 510} 511 512static void max8997_rtc_shutdown(struct platform_device *pdev) 513{ 514 struct max8997_rtc_info *info = platform_get_drvdata(pdev); 515 516 max8997_rtc_enable_wtsr(info, false); 517 max8997_rtc_enable_smpl(info, false); 518} 519 520static const struct platform_device_id rtc_id[] = { 521 { "max8997-rtc", 0 }, 522 {}, 523}; 524 525static struct platform_driver max8997_rtc_driver = { 526 .driver = { 527 .name = "max8997-rtc", 528 }, 529 .probe = max8997_rtc_probe, 530 .shutdown = max8997_rtc_shutdown, 531 .id_table = rtc_id, 532}; 533 534module_platform_driver(max8997_rtc_driver); 535 536MODULE_DESCRIPTION("Maxim MAX8997 RTC driver"); 537MODULE_AUTHOR("<ms925.kim@samsung.com>"); 538MODULE_LICENSE("GPL"); 539