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 */ 38 static 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 */ 97 static 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 */ 146 static 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 } 191 192 static 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 } 215 216 static 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 } 238 239 static 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 } 249 250 static 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 } 304 305 static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data) 306 { 307 struct wm8350 *wm8350 = data; 308 struct rtc_device *rtc = wm8350->rtc.rtc; 309 int ret; 310 311 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); 312 313 /* Make it one shot */ 314 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, 315 WM8350_RTC_ALMSET); 316 if (ret != 0) { 317 dev_err(&(wm8350->rtc.pdev->dev), 318 "Failed to disable alarm: %d\n", ret); 319 } 320 321 return IRQ_HANDLED; 322 } 323 324 static irqreturn_t wm8350_rtc_update_handler(int irq, void *data) 325 { 326 struct wm8350 *wm8350 = data; 327 struct rtc_device *rtc = wm8350->rtc.rtc; 328 329 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF); 330 331 return IRQ_HANDLED; 332 } 333 334 static const struct rtc_class_ops wm8350_rtc_ops = { 335 .read_time = wm8350_rtc_readtime, 336 .set_time = wm8350_rtc_settime, 337 .read_alarm = wm8350_rtc_readalarm, 338 .set_alarm = wm8350_rtc_setalarm, 339 .alarm_irq_enable = wm8350_rtc_alarm_irq_enable, 340 }; 341 342 #ifdef CONFIG_PM_SLEEP 343 static int wm8350_rtc_suspend(struct device *dev) 344 { 345 struct platform_device *pdev = to_platform_device(dev); 346 struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev); 347 int ret = 0; 348 u16 reg; 349 350 reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 351 352 if (device_may_wakeup(&wm8350->rtc.pdev->dev) && 353 reg & WM8350_RTC_ALMSTS) { 354 ret = wm8350_rtc_stop_alarm(wm8350); 355 if (ret != 0) 356 dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", 357 ret); 358 } 359 360 return ret; 361 } 362 363 static int wm8350_rtc_resume(struct device *dev) 364 { 365 struct platform_device *pdev = to_platform_device(dev); 366 struct wm8350 *wm8350 = dev_get_drvdata(&pdev->dev); 367 int ret; 368 369 if (wm8350->rtc.alarm_enabled) { 370 ret = wm8350_rtc_start_alarm(wm8350); 371 if (ret != 0) 372 dev_err(&pdev->dev, 373 "Failed to restart RTC alarm: %d\n", ret); 374 } 375 376 return 0; 377 } 378 #endif 379 380 static int wm8350_rtc_probe(struct platform_device *pdev) 381 { 382 struct wm8350 *wm8350 = platform_get_drvdata(pdev); 383 struct wm8350_rtc *wm_rtc = &wm8350->rtc; 384 int ret = 0; 385 u16 timectl, power5; 386 387 timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL); 388 if (timectl & WM8350_RTC_BCD) { 389 dev_err(&pdev->dev, "RTC BCD mode not supported\n"); 390 return -EINVAL; 391 } 392 if (timectl & WM8350_RTC_12HR) { 393 dev_err(&pdev->dev, "RTC 12 hour mode not supported\n"); 394 return -EINVAL; 395 } 396 397 /* enable the RTC if it's not already enabled */ 398 power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5); 399 if (!(power5 & WM8350_RTC_TICK_ENA)) { 400 dev_info(wm8350->dev, "Starting RTC\n"); 401 402 wm8350_reg_unlock(wm8350); 403 404 ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5, 405 WM8350_RTC_TICK_ENA); 406 if (ret < 0) { 407 dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret); 408 return ret; 409 } 410 411 wm8350_reg_lock(wm8350); 412 } 413 414 if (timectl & WM8350_RTC_STS) { 415 int retries; 416 417 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL, 418 WM8350_RTC_SET); 419 if (ret < 0) { 420 dev_err(&pdev->dev, "failed to start: %d\n", ret); 421 return ret; 422 } 423 424 retries = WM8350_SET_TIME_RETRIES; 425 do { 426 timectl = wm8350_reg_read(wm8350, 427 WM8350_RTC_TIME_CONTROL); 428 } while (timectl & WM8350_RTC_STS && --retries); 429 430 if (retries == 0) { 431 dev_err(&pdev->dev, "failed to start: timeout\n"); 432 return -ENODEV; 433 } 434 } 435 436 device_init_wakeup(&pdev->dev, 1); 437 438 wm_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm8350", 439 &wm8350_rtc_ops, THIS_MODULE); 440 if (IS_ERR(wm_rtc->rtc)) { 441 ret = PTR_ERR(wm_rtc->rtc); 442 dev_err(&pdev->dev, "failed to register RTC: %d\n", ret); 443 return ret; 444 } 445 446 wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC, 447 wm8350_rtc_update_handler, 0, 448 "RTC Seconds", wm8350); 449 wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC); 450 451 wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM, 452 wm8350_rtc_alarm_handler, 0, 453 "RTC Alarm", wm8350); 454 455 return 0; 456 } 457 458 static int wm8350_rtc_remove(struct platform_device *pdev) 459 { 460 struct wm8350 *wm8350 = platform_get_drvdata(pdev); 461 462 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350); 463 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350); 464 465 return 0; 466 } 467 468 static SIMPLE_DEV_PM_OPS(wm8350_rtc_pm_ops, wm8350_rtc_suspend, 469 wm8350_rtc_resume); 470 471 static struct platform_driver wm8350_rtc_driver = { 472 .probe = wm8350_rtc_probe, 473 .remove = wm8350_rtc_remove, 474 .driver = { 475 .name = "wm8350-rtc", 476 .pm = &wm8350_rtc_pm_ops, 477 }, 478 }; 479 480 module_platform_driver(wm8350_rtc_driver); 481 482 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 483 MODULE_DESCRIPTION("RTC driver for the WM8350"); 484 MODULE_LICENSE("GPL"); 485 MODULE_ALIAS("platform:wm8350-rtc"); 486