1/* 2 * RTC driver for Maxim MAX77802 3 * 4 * Copyright (C) 2013 Google, Inc 5 * 6 * Copyright (C) 2012 Samsung Electronics Co.Ltd 7 * 8 * based on rtc-max8997.c 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the 12 * Free Software Foundation; either version 2 of the License, or (at your 13 * option) any later version. 14 * 15 */ 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/max77686-private.h> 24#include <linux/irqdomain.h> 25#include <linux/regmap.h> 26 27/* RTC Control Register */ 28#define BCD_EN_SHIFT 0 29#define BCD_EN_MASK (1 << BCD_EN_SHIFT) 30#define MODEL24_SHIFT 1 31#define MODEL24_MASK (1 << MODEL24_SHIFT) 32/* RTC Update Register1 */ 33#define RTC_UDR_SHIFT 0 34#define RTC_UDR_MASK (1 << RTC_UDR_SHIFT) 35#define RTC_RBUDR_SHIFT 4 36#define RTC_RBUDR_MASK (1 << RTC_RBUDR_SHIFT) 37/* RTC Hour register */ 38#define HOUR_PM_SHIFT 6 39#define HOUR_PM_MASK (1 << HOUR_PM_SHIFT) 40/* RTC Alarm Enable */ 41#define ALARM_ENABLE_SHIFT 7 42#define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT) 43 44/* For the RTCAE1 register, we write this value to enable the alarm */ 45#define ALARM_ENABLE_VALUE 0x77 46 47#define MAX77802_RTC_UPDATE_DELAY_US 200 48 49enum { 50 RTC_SEC = 0, 51 RTC_MIN, 52 RTC_HOUR, 53 RTC_WEEKDAY, 54 RTC_MONTH, 55 RTC_YEAR, 56 RTC_DATE, 57 RTC_NR_TIME 58}; 59 60struct max77802_rtc_info { 61 struct device *dev; 62 struct max77686_dev *max77802; 63 struct i2c_client *rtc; 64 struct rtc_device *rtc_dev; 65 struct mutex lock; 66 67 struct regmap *regmap; 68 69 int virq; 70 int rtc_24hr_mode; 71}; 72 73enum MAX77802_RTC_OP { 74 MAX77802_RTC_WRITE, 75 MAX77802_RTC_READ, 76}; 77 78static void max77802_rtc_data_to_tm(u8 *data, struct rtc_time *tm, 79 int rtc_24hr_mode) 80{ 81 tm->tm_sec = data[RTC_SEC] & 0xff; 82 tm->tm_min = data[RTC_MIN] & 0xff; 83 if (rtc_24hr_mode) 84 tm->tm_hour = data[RTC_HOUR] & 0x1f; 85 else { 86 tm->tm_hour = data[RTC_HOUR] & 0x0f; 87 if (data[RTC_HOUR] & HOUR_PM_MASK) 88 tm->tm_hour += 12; 89 } 90 91 /* Only a single bit is set in data[], so fls() would be equivalent */ 92 tm->tm_wday = ffs(data[RTC_WEEKDAY] & 0xff) - 1; 93 tm->tm_mday = data[RTC_DATE] & 0x1f; 94 tm->tm_mon = (data[RTC_MONTH] & 0x0f) - 1; 95 96 tm->tm_year = data[RTC_YEAR] & 0xff; 97 tm->tm_yday = 0; 98 tm->tm_isdst = 0; 99} 100 101static int max77802_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; 110 111 return 0; 112} 113 114static int max77802_rtc_update(struct max77802_rtc_info *info, 115 enum MAX77802_RTC_OP op) 116{ 117 int ret; 118 unsigned int data; 119 120 if (op == MAX77802_RTC_WRITE) 121 data = 1 << RTC_UDR_SHIFT; 122 else 123 data = 1 << RTC_RBUDR_SHIFT; 124 125 ret = regmap_update_bits(info->max77802->regmap, 126 MAX77802_RTC_UPDATE0, data, data); 127 if (ret < 0) 128 dev_err(info->dev, "%s: fail to write update reg(ret=%d, data=0x%x)\n", 129 __func__, ret, data); 130 else { 131 /* Minimum delay required before RTC update. */ 132 usleep_range(MAX77802_RTC_UPDATE_DELAY_US, 133 MAX77802_RTC_UPDATE_DELAY_US * 2); 134 } 135 136 return ret; 137} 138 139static int max77802_rtc_read_time(struct device *dev, struct rtc_time *tm) 140{ 141 struct max77802_rtc_info *info = dev_get_drvdata(dev); 142 u8 data[RTC_NR_TIME]; 143 int ret; 144 145 mutex_lock(&info->lock); 146 147 ret = max77802_rtc_update(info, MAX77802_RTC_READ); 148 if (ret < 0) 149 goto out; 150 151 ret = regmap_bulk_read(info->max77802->regmap, 152 MAX77802_RTC_SEC, data, RTC_NR_TIME); 153 if (ret < 0) { 154 dev_err(info->dev, "%s: fail to read time reg(%d)\n", __func__, 155 ret); 156 goto out; 157 } 158 159 max77802_rtc_data_to_tm(data, tm, info->rtc_24hr_mode); 160 161 ret = rtc_valid_tm(tm); 162 163out: 164 mutex_unlock(&info->lock); 165 return ret; 166} 167 168static int max77802_rtc_set_time(struct device *dev, struct rtc_time *tm) 169{ 170 struct max77802_rtc_info *info = dev_get_drvdata(dev); 171 u8 data[RTC_NR_TIME]; 172 int ret; 173 174 ret = max77802_rtc_tm_to_data(tm, data); 175 if (ret < 0) 176 return ret; 177 178 mutex_lock(&info->lock); 179 180 ret = regmap_bulk_write(info->max77802->regmap, 181 MAX77802_RTC_SEC, data, RTC_NR_TIME); 182 if (ret < 0) { 183 dev_err(info->dev, "%s: fail to write time reg(%d)\n", __func__, 184 ret); 185 goto out; 186 } 187 188 ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); 189 190out: 191 mutex_unlock(&info->lock); 192 return ret; 193} 194 195static int max77802_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 196{ 197 struct max77802_rtc_info *info = dev_get_drvdata(dev); 198 u8 data[RTC_NR_TIME]; 199 unsigned int val; 200 int ret; 201 202 mutex_lock(&info->lock); 203 204 ret = max77802_rtc_update(info, MAX77802_RTC_READ); 205 if (ret < 0) 206 goto out; 207 208 ret = regmap_bulk_read(info->max77802->regmap, 209 MAX77802_ALARM1_SEC, data, RTC_NR_TIME); 210 if (ret < 0) { 211 dev_err(info->dev, "%s:%d fail to read alarm reg(%d)\n", 212 __func__, __LINE__, ret); 213 goto out; 214 } 215 216 max77802_rtc_data_to_tm(data, &alrm->time, info->rtc_24hr_mode); 217 218 alrm->enabled = 0; 219 ret = regmap_read(info->max77802->regmap, 220 MAX77802_RTC_AE1, &val); 221 if (ret < 0) { 222 dev_err(info->dev, "%s:%d fail to read alarm enable(%d)\n", 223 __func__, __LINE__, ret); 224 goto out; 225 } 226 if (val) 227 alrm->enabled = 1; 228 229 alrm->pending = 0; 230 ret = regmap_read(info->max77802->regmap, MAX77802_REG_STATUS2, &val); 231 if (ret < 0) { 232 dev_err(info->dev, "%s:%d fail to read status2 reg(%d)\n", 233 __func__, __LINE__, ret); 234 goto out; 235 } 236 237 if (val & (1 << 2)) /* RTCA1 */ 238 alrm->pending = 1; 239 240out: 241 mutex_unlock(&info->lock); 242 return 0; 243} 244 245static int max77802_rtc_stop_alarm(struct max77802_rtc_info *info) 246{ 247 int ret; 248 249 if (!mutex_is_locked(&info->lock)) 250 dev_warn(info->dev, "%s: should have mutex locked\n", __func__); 251 252 ret = max77802_rtc_update(info, MAX77802_RTC_READ); 253 if (ret < 0) 254 goto out; 255 256 ret = regmap_write(info->max77802->regmap, 257 MAX77802_RTC_AE1, 0); 258 if (ret < 0) { 259 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", 260 __func__, ret); 261 goto out; 262 } 263 264 ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); 265out: 266 return ret; 267} 268 269static int max77802_rtc_start_alarm(struct max77802_rtc_info *info) 270{ 271 int ret; 272 273 if (!mutex_is_locked(&info->lock)) 274 dev_warn(info->dev, "%s: should have mutex locked\n", 275 __func__); 276 277 ret = max77802_rtc_update(info, MAX77802_RTC_READ); 278 if (ret < 0) 279 goto out; 280 281 ret = regmap_write(info->max77802->regmap, 282 MAX77802_RTC_AE1, 283 ALARM_ENABLE_VALUE); 284 285 if (ret < 0) { 286 dev_err(info->dev, "%s: fail to read alarm reg(%d)\n", 287 __func__, ret); 288 goto out; 289 } 290 291 ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); 292out: 293 return ret; 294} 295 296static int max77802_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 297{ 298 struct max77802_rtc_info *info = dev_get_drvdata(dev); 299 u8 data[RTC_NR_TIME]; 300 int ret; 301 302 ret = max77802_rtc_tm_to_data(&alrm->time, data); 303 if (ret < 0) 304 return ret; 305 306 mutex_lock(&info->lock); 307 308 ret = max77802_rtc_stop_alarm(info); 309 if (ret < 0) 310 goto out; 311 312 ret = regmap_bulk_write(info->max77802->regmap, 313 MAX77802_ALARM1_SEC, data, RTC_NR_TIME); 314 315 if (ret < 0) { 316 dev_err(info->dev, "%s: fail to write alarm reg(%d)\n", 317 __func__, ret); 318 goto out; 319 } 320 321 ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); 322 if (ret < 0) 323 goto out; 324 325 if (alrm->enabled) 326 ret = max77802_rtc_start_alarm(info); 327out: 328 mutex_unlock(&info->lock); 329 return ret; 330} 331 332static int max77802_rtc_alarm_irq_enable(struct device *dev, 333 unsigned int enabled) 334{ 335 struct max77802_rtc_info *info = dev_get_drvdata(dev); 336 int ret; 337 338 mutex_lock(&info->lock); 339 if (enabled) 340 ret = max77802_rtc_start_alarm(info); 341 else 342 ret = max77802_rtc_stop_alarm(info); 343 mutex_unlock(&info->lock); 344 345 return ret; 346} 347 348static irqreturn_t max77802_rtc_alarm_irq(int irq, void *data) 349{ 350 struct max77802_rtc_info *info = data; 351 352 dev_dbg(info->dev, "%s:irq(%d)\n", __func__, irq); 353 354 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 355 356 return IRQ_HANDLED; 357} 358 359static const struct rtc_class_ops max77802_rtc_ops = { 360 .read_time = max77802_rtc_read_time, 361 .set_time = max77802_rtc_set_time, 362 .read_alarm = max77802_rtc_read_alarm, 363 .set_alarm = max77802_rtc_set_alarm, 364 .alarm_irq_enable = max77802_rtc_alarm_irq_enable, 365}; 366 367static int max77802_rtc_init_reg(struct max77802_rtc_info *info) 368{ 369 u8 data[2]; 370 int ret; 371 372 max77802_rtc_update(info, MAX77802_RTC_READ); 373 374 /* Set RTC control register : Binary mode, 24hour mdoe */ 375 data[0] = (1 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); 376 data[1] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT); 377 378 info->rtc_24hr_mode = 1; 379 380 ret = regmap_bulk_write(info->max77802->regmap, 381 MAX77802_RTC_CONTROLM, data, ARRAY_SIZE(data)); 382 if (ret < 0) { 383 dev_err(info->dev, "%s: fail to write controlm reg(%d)\n", 384 __func__, ret); 385 return ret; 386 } 387 388 ret = max77802_rtc_update(info, MAX77802_RTC_WRITE); 389 return ret; 390} 391 392static int max77802_rtc_probe(struct platform_device *pdev) 393{ 394 struct max77686_dev *max77802 = dev_get_drvdata(pdev->dev.parent); 395 struct max77802_rtc_info *info; 396 int ret; 397 398 dev_dbg(&pdev->dev, "%s\n", __func__); 399 400 info = devm_kzalloc(&pdev->dev, sizeof(struct max77802_rtc_info), 401 GFP_KERNEL); 402 if (!info) 403 return -ENOMEM; 404 405 mutex_init(&info->lock); 406 info->dev = &pdev->dev; 407 info->max77802 = max77802; 408 info->rtc = max77802->i2c; 409 410 platform_set_drvdata(pdev, info); 411 412 ret = max77802_rtc_init_reg(info); 413 414 if (ret < 0) { 415 dev_err(&pdev->dev, "Failed to initialize RTC reg:%d\n", ret); 416 return ret; 417 } 418 419 device_init_wakeup(&pdev->dev, 1); 420 421 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max77802-rtc", 422 &max77802_rtc_ops, THIS_MODULE); 423 424 if (IS_ERR(info->rtc_dev)) { 425 ret = PTR_ERR(info->rtc_dev); 426 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 427 if (ret == 0) 428 ret = -EINVAL; 429 return ret; 430 } 431 432 if (!max77802->rtc_irq_data) { 433 dev_err(&pdev->dev, "No RTC regmap IRQ chip\n"); 434 return -EINVAL; 435 } 436 437 info->virq = regmap_irq_get_virq(max77802->rtc_irq_data, 438 MAX77686_RTCIRQ_RTCA1); 439 440 if (info->virq <= 0) { 441 dev_err(&pdev->dev, "Failed to get virtual IRQ %d\n", 442 MAX77686_RTCIRQ_RTCA1); 443 return -EINVAL; 444 } 445 446 ret = devm_request_threaded_irq(&pdev->dev, info->virq, NULL, 447 max77802_rtc_alarm_irq, 0, "rtc-alarm1", 448 info); 449 if (ret < 0) 450 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", 451 info->virq, ret); 452 453 return ret; 454} 455 456#ifdef CONFIG_PM_SLEEP 457static int max77802_rtc_suspend(struct device *dev) 458{ 459 if (device_may_wakeup(dev)) { 460 struct max77802_rtc_info *info = dev_get_drvdata(dev); 461 462 return enable_irq_wake(info->virq); 463 } 464 465 return 0; 466} 467 468static int max77802_rtc_resume(struct device *dev) 469{ 470 if (device_may_wakeup(dev)) { 471 struct max77802_rtc_info *info = dev_get_drvdata(dev); 472 473 return disable_irq_wake(info->virq); 474 } 475 476 return 0; 477} 478#endif 479 480static SIMPLE_DEV_PM_OPS(max77802_rtc_pm_ops, 481 max77802_rtc_suspend, max77802_rtc_resume); 482 483static const struct platform_device_id rtc_id[] = { 484 { "max77802-rtc", 0 }, 485 {}, 486}; 487 488static struct platform_driver max77802_rtc_driver = { 489 .driver = { 490 .name = "max77802-rtc", 491 .owner = THIS_MODULE, 492 .pm = &max77802_rtc_pm_ops, 493 }, 494 .probe = max77802_rtc_probe, 495 .id_table = rtc_id, 496}; 497 498module_platform_driver(max77802_rtc_driver); 499 500MODULE_DESCRIPTION("Maxim MAX77802 RTC driver"); 501MODULE_AUTHOR("Simon Glass <sjg@chromium.org>"); 502MODULE_LICENSE("GPL"); 503