1/* 2 * Real Time Clock driver for Wolfson Microelectronics WM8350 3 * 4 * Copyright (C) 2007, 2008 Wolfson Microelectronics PLC. 5 * 6 * Author: Liam Girdwood 7 * linux@wolfsonmicro.com 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License as published by the 11 * Free Software Foundation; either version 2 of the License, or (at your 12 * option) any later version. 13 * 14 */ 15 16#include <linux/module.h> 17#include <linux/kernel.h> 18#include <linux/time.h> 19#include <linux/rtc.h> 20#include <linux/bcd.h> 21#include <linux/interrupt.h> 22#include <linux/ioctl.h> 23#include <linux/completion.h> 24#include <linux/mfd/wm8350/rtc.h> 25#include <linux/mfd/wm8350/core.h> 26#include <linux/delay.h> 27#include <linux/platform_device.h> 28 29#define WM8350_SET_ALM_RETRIES 5 30#define WM8350_SET_TIME_RETRIES 5 31#define WM8350_GET_TIME_RETRIES 5 32 33#define to_wm8350_from_rtc_dev(d) container_of(d, struct wm8350, rtc.pdev.dev) 34 35/* 36 * Read current time and date in RTC 37 */ 38static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm) 39{ 40 struct wm8350 *wm8350 = dev_get_drvdata(dev); 41 u16 time1[4], time2[4]; 42 int retries = WM8350_GET_TIME_RETRIES, ret; 43 44 /* 45 * Read the time twice and compare. 46 * If time1 == time2, then time is valid else retry. 47 */ 48 do { 49 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES, 50 4, time1); 51 if (ret < 0) 52 return ret; 53 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES, 54 4, time2); 55 if (ret < 0) 56 return ret; 57 58 if (memcmp(time1, time2, sizeof(time1)) == 0) { 59 tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK; 60 61 tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK) 62 >> WM8350_RTC_MINS_SHIFT; 63 64 tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK; 65 66 tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT) 67 & 0x7) - 1; 68 69 tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK) 70 >> WM8350_RTC_MTH_SHIFT) - 1; 71 72 tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK); 73 74 tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK) 75 >> WM8350_RTC_YHUNDREDS_SHIFT) * 100; 76 tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK; 77 78 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, 79 tm->tm_year); 80 tm->tm_year -= 1900; 81 82 dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n", 83 retries, 84 time1[0], time1[1], time1[2], time1[3]); 85 86 return 0; 87 } 88 } while (retries--); 89 90 dev_err(dev, "timed out reading RTC time\n"); 91 return -EIO; 92} 93 94/* 95 * Set current time and date in RTC 96 */ 97static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm) 98{ 99 struct wm8350 *wm8350 = dev_get_drvdata(dev); 100 u16 time[4]; 101 u16 rtc_ctrl; 102 int ret, retries = WM8350_SET_TIME_RETRIES; 103 104 time[0] = tm->tm_sec; 105 time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT; 106 time[1] = tm->tm_hour; 107 time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT; 108 time[2] = tm->tm_mday; 109 time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT; 110 time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT; 111 time[3] |= (tm->tm_year + 1900) % 100; 112 113 dev_dbg(dev, "Setting: %04x %04x %04x %04x\n", 114 time[0], time[1], time[2], time[3]); 115 116 /* Set RTC_SET to stop the clock */ 117 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET); 118 if (ret < 0) 119 return ret; 120 121 /* Wait until confirmation of stopping */ 122 do { 123 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 124 schedule_timeout_uninterruptible(msecs_to_jiffies(1)); 125 } while (--retries && !(rtc_ctrl & WM8350_RTC_STS)); 126 127 if (!retries) { 128 dev_err(dev, "timed out on set confirmation\n"); 129 return -EIO; 130 } 131 132 /* Write time to RTC */ 133 ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time); 134 if (ret < 0) 135 return ret; 136 137 /* Clear RTC_SET to start the clock */ 138 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL, 139 WM8350_RTC_SET); 140 return ret; 141} 142 143/* 144 * Read alarm time and date in RTC 145 */ 146static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 147{ 148 struct wm8350 *wm8350 = dev_get_drvdata(dev); 149 struct rtc_time *tm = &alrm->time; 150 u16 time[4]; 151 int ret; 152 153 ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time); 154 if (ret < 0) 155 return ret; 156 157 tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK; 158 if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK) 159 tm->tm_sec = -1; 160 161 tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK; 162 if (tm->tm_min == WM8350_RTC_ALMMINS_MASK) 163 tm->tm_min = -1; 164 else 165 tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT; 166 167 tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK; 168 if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK) 169 tm->tm_hour = -1; 170 171 tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1; 172 if (tm->tm_wday > 7) 173 tm->tm_wday = -1; 174 175 tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK; 176 if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK) 177 tm->tm_mon = -1; 178 else 179 tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1; 180 181 tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK); 182 if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK) 183 tm->tm_mday = -1; 184 185 tm->tm_year = -1; 186 187 alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS); 188 189 return 0; 190} 191 192static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350) 193{ 194 int retries = WM8350_SET_ALM_RETRIES; 195 u16 rtc_ctrl; 196 int ret; 197 198 /* Set RTC_SET to stop the clock */ 199 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, 200 WM8350_RTC_ALMSET); 201 if (ret < 0) 202 return ret; 203 204 /* Wait until confirmation of stopping */ 205 do { 206 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 207 schedule_timeout_uninterruptible(msecs_to_jiffies(1)); 208 } while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS)); 209 210 if (!(rtc_ctrl & WM8350_RTC_ALMSTS)) 211 return -ETIMEDOUT; 212 213 return 0; 214} 215 216static int wm8350_rtc_start_alarm(struct wm8350 *wm8350) 217{ 218 int ret; 219 int retries = WM8350_SET_ALM_RETRIES; 220 u16 rtc_ctrl; 221 222 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL, 223 WM8350_RTC_ALMSET); 224 if (ret < 0) 225 return ret; 226 227 /* Wait until confirmation */ 228 do { 229 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 230 schedule_timeout_uninterruptible(msecs_to_jiffies(1)); 231 } while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS); 232 233 if (rtc_ctrl & WM8350_RTC_ALMSTS) 234 return -ETIMEDOUT; 235 236 return 0; 237} 238 239static int wm8350_rtc_alarm_irq_enable(struct device *dev, 240 unsigned int enabled) 241{ 242 struct wm8350 *wm8350 = dev_get_drvdata(dev); 243 244 if (enabled) 245 return wm8350_rtc_start_alarm(wm8350); 246 else 247 return wm8350_rtc_stop_alarm(wm8350); 248} 249 250static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 251{ 252 struct wm8350 *wm8350 = dev_get_drvdata(dev); 253 struct rtc_time *tm = &alrm->time; 254 u16 time[3]; 255 int ret; 256 257 memset(time, 0, sizeof(time)); 258 259 if (tm->tm_sec != -1) 260 time[0] |= tm->tm_sec; 261 else 262 time[0] |= WM8350_RTC_ALMSECS_MASK; 263 264 if (tm->tm_min != -1) 265 time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT; 266 else 267 time[0] |= WM8350_RTC_ALMMINS_MASK; 268 269 if (tm->tm_hour != -1) 270 time[1] |= tm->tm_hour; 271 else 272 time[1] |= WM8350_RTC_ALMHRS_MASK; 273 274 if (tm->tm_wday != -1) 275 time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT; 276 else 277 time[1] |= WM8350_RTC_ALMDAY_MASK; 278 279 if (tm->tm_mday != -1) 280 time[2] |= tm->tm_mday; 281 else 282 time[2] |= WM8350_RTC_ALMDATE_MASK; 283 284 if (tm->tm_mon != -1) 285 time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT; 286 else 287 time[2] |= WM8350_RTC_ALMMTH_MASK; 288 289 ret = wm8350_rtc_stop_alarm(wm8350); 290 if (ret < 0) 291 return ret; 292 293 /* Write time to RTC */ 294 ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES, 295 3, time); 296 if (ret < 0) 297 return ret; 298 299 if (alrm->enabled) 300 ret = wm8350_rtc_start_alarm(wm8350); 301 302 return ret; 303} 304 305static int wm8350_rtc_update_irq_enable(struct device *dev, 306 unsigned int enabled) 307{ 308 struct wm8350 *wm8350 = dev_get_drvdata(dev); 309 310 /* Suppress duplicate changes since genirq nests enable and 311 * disable calls. */ 312 if (enabled == wm8350->rtc.update_enabled) 313 return 0; 314 315 if (enabled) 316 wm8350_unmask_irq(wm8350, WM8350_IRQ_RTC_SEC); 317 else 318 wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC); 319 320 wm8350->rtc.update_enabled = enabled; 321 322 return 0; 323} 324 325static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data) 326{ 327 struct wm8350 *wm8350 = data; 328 struct rtc_device *rtc = wm8350->rtc.rtc; 329 int ret; 330 331 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); 332 333 /* Make it one shot */ 334 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, 335 WM8350_RTC_ALMSET); 336 if (ret != 0) { 337 dev_err(&(wm8350->rtc.pdev->dev), 338 "Failed to disable alarm: %d\n", ret); 339 } 340 341 return IRQ_HANDLED; 342} 343 344static irqreturn_t wm8350_rtc_update_handler(int irq, void *data) 345{ 346 struct wm8350 *wm8350 = data; 347 struct rtc_device *rtc = wm8350->rtc.rtc; 348 349 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF); 350 351 return IRQ_HANDLED; 352} 353 354static const struct rtc_class_ops wm8350_rtc_ops = { 355 .read_time = wm8350_rtc_readtime, 356 .set_time = wm8350_rtc_settime, 357 .read_alarm = wm8350_rtc_readalarm, 358 .set_alarm = wm8350_rtc_setalarm, 359 .alarm_irq_enable = wm8350_rtc_alarm_irq_enable, 360 .update_irq_enable = wm8350_rtc_update_irq_enable, 361}; 362 363#ifdef CONFIG_PM 364static int wm8350_rtc_suspend(struct device *dev) 365{ 366 struct platform_device *pdev = to_platform_device(dev); 367 struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev); 368 int ret = 0; 369 u16 reg; 370 371 reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 372 373 if (device_may_wakeup(&wm8350->rtc.pdev->dev) && 374 reg & WM8350_RTC_ALMSTS) { 375 ret = wm8350_rtc_stop_alarm(wm8350); 376 if (ret != 0) 377 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", 378 ret); 379 } 380 381 return ret; 382} 383 384static int wm8350_rtc_resume(struct device *dev) 385{ 386 struct platform_device *pdev = to_platform_device(dev); 387 struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev); 388 int ret; 389 390 if (wm8350->rtc.alarm_enabled) { 391 ret = wm8350_rtc_start_alarm(wm8350); 392 if (ret != 0) 393 dev_err(&pdev->dev, 394 "Failed to restart RTC alarm: %d\n", ret); 395 } 396 397 return 0; 398} 399 400#else 401#define wm8350_rtc_suspend NULL 402#define wm8350_rtc_resume NULL 403#endif 404 405static int wm8350_rtc_probe(struct platform_device *pdev) 406{ 407 struct wm8350 *wm8350 = platform_get_drvdata(pdev); 408 struct wm8350_rtc *wm_rtc = &wm8350->rtc; 409 int ret = 0; 410 u16 timectl, power5; 411 412 timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 413 if (timectl & WM8350_RTC_BCD) { 414 dev_err(&pdev->dev, "RTC BCD mode not supported\n"); 415 return -EINVAL; 416 } 417 if (timectl & WM8350_RTC_12HR) { 418 dev_err(&pdev->dev, "RTC 12 hour mode not supported\n"); 419 return -EINVAL; 420 } 421 422 /* enable the RTC if it's not already enabled */ 423 power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5); 424 if (!(power5 & WM8350_RTC_TICK_ENA)) { 425 dev_info(wm8350->dev, "Starting RTC\n"); 426 427 wm8350_reg_unlock(wm8350); 428 429 ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5, 430 WM8350_RTC_TICK_ENA); 431 if (ret < 0) { 432 dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret); 433 return ret; 434 } 435 436 wm8350_reg_lock(wm8350); 437 } 438 439 if (timectl & WM8350_RTC_STS) { 440 int retries; 441 442 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL, 443 WM8350_RTC_SET); 444 if (ret < 0) { 445 dev_err(&pdev->dev, "failed to start: %d\n", ret); 446 return ret; 447 } 448 449 retries = WM8350_SET_TIME_RETRIES; 450 do { 451 timectl = wm8350_reg_read(wm8350, 452 WM8350_RTC_TIME_CONTROL); 453 } while (timectl & WM8350_RTC_STS && --retries); 454 455 if (retries == 0) { 456 dev_err(&pdev->dev, "failed to start: timeout\n"); 457 return -ENODEV; 458 } 459 } 460 461 device_init_wakeup(&pdev->dev, 1); 462 463 wm_rtc->rtc = rtc_device_register("wm8350", &pdev->dev, 464 &wm8350_rtc_ops, THIS_MODULE); 465 if (IS_ERR(wm_rtc->rtc)) { 466 ret = PTR_ERR(wm_rtc->rtc); 467 dev_err(&pdev->dev, "failed to register RTC: %d\n", ret); 468 return ret; 469 } 470 471 wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC, 472 wm8350_rtc_update_handler, 0, 473 "RTC Seconds", wm8350); 474 wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC); 475 476 wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM, 477 wm8350_rtc_alarm_handler, 0, 478 "RTC Alarm", wm8350); 479 480 return 0; 481} 482 483static int __devexit wm8350_rtc_remove(struct platform_device *pdev) 484{ 485 struct wm8350 *wm8350 = platform_get_drvdata(pdev); 486 struct wm8350_rtc *wm_rtc = &wm8350->rtc; 487 488 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350); 489 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350); 490 491 rtc_device_unregister(wm_rtc->rtc); 492 493 return 0; 494} 495 496static struct dev_pm_ops wm8350_rtc_pm_ops = { 497 .suspend = wm8350_rtc_suspend, 498 .resume = wm8350_rtc_resume, 499}; 500 501static struct platform_driver wm8350_rtc_driver = { 502 .probe = wm8350_rtc_probe, 503 .remove = __devexit_p(wm8350_rtc_remove), 504 .driver = { 505 .name = "wm8350-rtc", 506 .pm = &wm8350_rtc_pm_ops, 507 }, 508}; 509 510static int __init wm8350_rtc_init(void) 511{ 512 return platform_driver_register(&wm8350_rtc_driver); 513} 514module_init(wm8350_rtc_init); 515 516static void __exit wm8350_rtc_exit(void) 517{ 518 platform_driver_unregister(&wm8350_rtc_driver); 519} 520module_exit(wm8350_rtc_exit); 521 522MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 523MODULE_DESCRIPTION("RTC driver for the WM8350"); 524MODULE_LICENSE("GPL"); 525MODULE_ALIAS("platform:wm8350-rtc"); 526