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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Real Time Clock driver for Wolfson Microelectronics WM83504 *5 * Copyright (C) 2007, 2008 Wolfson Microelectronics PLC.6 *7 * Author: Liam Girdwood8 * linux@wolfsonmicro.com9 */10 11#include <linux/module.h>12#include <linux/kernel.h>13#include <linux/time.h>14#include <linux/rtc.h>15#include <linux/bcd.h>16#include <linux/interrupt.h>17#include <linux/ioctl.h>18#include <linux/completion.h>19#include <linux/mfd/wm8350/rtc.h>20#include <linux/mfd/wm8350/core.h>21#include <linux/delay.h>22#include <linux/platform_device.h>23 24#define WM8350_SET_ALM_RETRIES 525#define WM8350_SET_TIME_RETRIES 526#define WM8350_GET_TIME_RETRIES 527 28/*29 * Read current time and date in RTC30 */31static int wm8350_rtc_readtime(struct device *dev, struct rtc_time *tm)32{33 struct wm8350 *wm8350 = dev_get_drvdata(dev);34 u16 time1[4], time2[4];35 int retries = WM8350_GET_TIME_RETRIES, ret;36 37 /*38 * Read the time twice and compare.39 * If time1 == time2, then time is valid else retry.40 */41 do {42 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,43 4, time1);44 if (ret < 0)45 return ret;46 ret = wm8350_block_read(wm8350, WM8350_RTC_SECONDS_MINUTES,47 4, time2);48 if (ret < 0)49 return ret;50 51 if (memcmp(time1, time2, sizeof(time1)) == 0) {52 tm->tm_sec = time1[0] & WM8350_RTC_SECS_MASK;53 54 tm->tm_min = (time1[0] & WM8350_RTC_MINS_MASK)55 >> WM8350_RTC_MINS_SHIFT;56 57 tm->tm_hour = time1[1] & WM8350_RTC_HRS_MASK;58 59 tm->tm_wday = ((time1[1] >> WM8350_RTC_DAY_SHIFT)60 & 0x7) - 1;61 62 tm->tm_mon = ((time1[2] & WM8350_RTC_MTH_MASK)63 >> WM8350_RTC_MTH_SHIFT) - 1;64 65 tm->tm_mday = (time1[2] & WM8350_RTC_DATE_MASK);66 67 tm->tm_year = ((time1[3] & WM8350_RTC_YHUNDREDS_MASK)68 >> WM8350_RTC_YHUNDREDS_SHIFT) * 100;69 tm->tm_year += time1[3] & WM8350_RTC_YUNITS_MASK;70 71 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon,72 tm->tm_year);73 tm->tm_year -= 1900;74 75 dev_dbg(dev, "Read (%d left): %04x %04x %04x %04x\n",76 retries,77 time1[0], time1[1], time1[2], time1[3]);78 79 return 0;80 }81 } while (retries--);82 83 dev_err(dev, "timed out reading RTC time\n");84 return -EIO;85}86 87/*88 * Set current time and date in RTC89 */90static int wm8350_rtc_settime(struct device *dev, struct rtc_time *tm)91{92 struct wm8350 *wm8350 = dev_get_drvdata(dev);93 u16 time[4];94 u16 rtc_ctrl;95 int ret, retries = WM8350_SET_TIME_RETRIES;96 97 time[0] = tm->tm_sec;98 time[0] |= tm->tm_min << WM8350_RTC_MINS_SHIFT;99 time[1] = tm->tm_hour;100 time[1] |= (tm->tm_wday + 1) << WM8350_RTC_DAY_SHIFT;101 time[2] = tm->tm_mday;102 time[2] |= (tm->tm_mon + 1) << WM8350_RTC_MTH_SHIFT;103 time[3] = ((tm->tm_year + 1900) / 100) << WM8350_RTC_YHUNDREDS_SHIFT;104 time[3] |= (tm->tm_year + 1900) % 100;105 106 dev_dbg(dev, "Setting: %04x %04x %04x %04x\n",107 time[0], time[1], time[2], time[3]);108 109 /* Set RTC_SET to stop the clock */110 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL, WM8350_RTC_SET);111 if (ret < 0)112 return ret;113 114 /* Wait until confirmation of stopping */115 do {116 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);117 schedule_timeout_uninterruptible(msecs_to_jiffies(1));118 } while (--retries && !(rtc_ctrl & WM8350_RTC_STS));119 120 if (!retries) {121 dev_err(dev, "timed out on set confirmation\n");122 return -EIO;123 }124 125 /* Write time to RTC */126 ret = wm8350_block_write(wm8350, WM8350_RTC_SECONDS_MINUTES, 4, time);127 if (ret < 0)128 return ret;129 130 /* Clear RTC_SET to start the clock */131 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,132 WM8350_RTC_SET);133 return ret;134}135 136/*137 * Read alarm time and date in RTC138 */139static int wm8350_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)140{141 struct wm8350 *wm8350 = dev_get_drvdata(dev);142 struct rtc_time *tm = &alrm->time;143 u16 time[4];144 int ret;145 146 ret = wm8350_block_read(wm8350, WM8350_ALARM_SECONDS_MINUTES, 4, time);147 if (ret < 0)148 return ret;149 150 tm->tm_sec = time[0] & WM8350_RTC_ALMSECS_MASK;151 if (tm->tm_sec == WM8350_RTC_ALMSECS_MASK)152 tm->tm_sec = -1;153 154 tm->tm_min = time[0] & WM8350_RTC_ALMMINS_MASK;155 if (tm->tm_min == WM8350_RTC_ALMMINS_MASK)156 tm->tm_min = -1;157 else158 tm->tm_min >>= WM8350_RTC_ALMMINS_SHIFT;159 160 tm->tm_hour = time[1] & WM8350_RTC_ALMHRS_MASK;161 if (tm->tm_hour == WM8350_RTC_ALMHRS_MASK)162 tm->tm_hour = -1;163 164 tm->tm_wday = ((time[1] >> WM8350_RTC_ALMDAY_SHIFT) & 0x7) - 1;165 if (tm->tm_wday > 7)166 tm->tm_wday = -1;167 168 tm->tm_mon = time[2] & WM8350_RTC_ALMMTH_MASK;169 if (tm->tm_mon == WM8350_RTC_ALMMTH_MASK)170 tm->tm_mon = -1;171 else172 tm->tm_mon = (tm->tm_mon >> WM8350_RTC_ALMMTH_SHIFT) - 1;173 174 tm->tm_mday = (time[2] & WM8350_RTC_ALMDATE_MASK);175 if (tm->tm_mday == WM8350_RTC_ALMDATE_MASK)176 tm->tm_mday = -1;177 178 tm->tm_year = -1;179 180 alrm->enabled = !(time[3] & WM8350_RTC_ALMSTS);181 182 return 0;183}184 185static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)186{187 int retries = WM8350_SET_ALM_RETRIES;188 u16 rtc_ctrl;189 int ret;190 191 /* Set RTC_SET to stop the clock */192 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,193 WM8350_RTC_ALMSET);194 if (ret < 0)195 return ret;196 197 /* Wait until confirmation of stopping */198 do {199 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);200 schedule_timeout_uninterruptible(msecs_to_jiffies(1));201 } while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));202 203 if (!(rtc_ctrl & WM8350_RTC_ALMSTS))204 return -ETIMEDOUT;205 206 return 0;207}208 209static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)210{211 int ret;212 int retries = WM8350_SET_ALM_RETRIES;213 u16 rtc_ctrl;214 215 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,216 WM8350_RTC_ALMSET);217 if (ret < 0)218 return ret;219 220 /* Wait until confirmation */221 do {222 rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);223 schedule_timeout_uninterruptible(msecs_to_jiffies(1));224 } while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);225 226 if (rtc_ctrl & WM8350_RTC_ALMSTS)227 return -ETIMEDOUT;228 229 return 0;230}231 232static int wm8350_rtc_alarm_irq_enable(struct device *dev,233 unsigned int enabled)234{235 struct wm8350 *wm8350 = dev_get_drvdata(dev);236 237 if (enabled)238 return wm8350_rtc_start_alarm(wm8350);239 else240 return wm8350_rtc_stop_alarm(wm8350);241}242 243static int wm8350_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)244{245 struct wm8350 *wm8350 = dev_get_drvdata(dev);246 struct rtc_time *tm = &alrm->time;247 u16 time[3];248 int ret;249 250 memset(time, 0, sizeof(time));251 252 if (tm->tm_sec != -1)253 time[0] |= tm->tm_sec;254 else255 time[0] |= WM8350_RTC_ALMSECS_MASK;256 257 if (tm->tm_min != -1)258 time[0] |= tm->tm_min << WM8350_RTC_ALMMINS_SHIFT;259 else260 time[0] |= WM8350_RTC_ALMMINS_MASK;261 262 if (tm->tm_hour != -1)263 time[1] |= tm->tm_hour;264 else265 time[1] |= WM8350_RTC_ALMHRS_MASK;266 267 if (tm->tm_wday != -1)268 time[1] |= (tm->tm_wday + 1) << WM8350_RTC_ALMDAY_SHIFT;269 else270 time[1] |= WM8350_RTC_ALMDAY_MASK;271 272 if (tm->tm_mday != -1)273 time[2] |= tm->tm_mday;274 else275 time[2] |= WM8350_RTC_ALMDATE_MASK;276 277 if (tm->tm_mon != -1)278 time[2] |= (tm->tm_mon + 1) << WM8350_RTC_ALMMTH_SHIFT;279 else280 time[2] |= WM8350_RTC_ALMMTH_MASK;281 282 ret = wm8350_rtc_stop_alarm(wm8350);283 if (ret < 0)284 return ret;285 286 /* Write time to RTC */287 ret = wm8350_block_write(wm8350, WM8350_ALARM_SECONDS_MINUTES,288 3, time);289 if (ret < 0)290 return ret;291 292 if (alrm->enabled)293 ret = wm8350_rtc_start_alarm(wm8350);294 295 return ret;296}297 298static irqreturn_t wm8350_rtc_alarm_handler(int irq, void *data)299{300 struct wm8350 *wm8350 = data;301 struct rtc_device *rtc = wm8350->rtc.rtc;302 int ret;303 304 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);305 306 /* Make it one shot */307 ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,308 WM8350_RTC_ALMSET);309 if (ret != 0) {310 dev_err(&(wm8350->rtc.pdev->dev),311 "Failed to disable alarm: %d\n", ret);312 }313 314 return IRQ_HANDLED;315}316 317static irqreturn_t wm8350_rtc_update_handler(int irq, void *data)318{319 struct wm8350 *wm8350 = data;320 struct rtc_device *rtc = wm8350->rtc.rtc;321 322 rtc_update_irq(rtc, 1, RTC_IRQF | RTC_UF);323 324 return IRQ_HANDLED;325}326 327static const struct rtc_class_ops wm8350_rtc_ops = {328 .read_time = wm8350_rtc_readtime,329 .set_time = wm8350_rtc_settime,330 .read_alarm = wm8350_rtc_readalarm,331 .set_alarm = wm8350_rtc_setalarm,332 .alarm_irq_enable = wm8350_rtc_alarm_irq_enable,333};334 335#ifdef CONFIG_PM_SLEEP336static int wm8350_rtc_suspend(struct device *dev)337{338 struct wm8350 *wm8350 = dev_get_drvdata(dev);339 int ret = 0;340 u16 reg;341 342 reg = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);343 344 if (device_may_wakeup(&wm8350->rtc.pdev->dev) &&345 reg & WM8350_RTC_ALMSTS) {346 ret = wm8350_rtc_stop_alarm(wm8350);347 if (ret != 0)348 dev_err(dev, "Failed to stop RTC alarm: %d\n", ret);349 }350 351 return ret;352}353 354static int wm8350_rtc_resume(struct device *dev)355{356 struct wm8350 *wm8350 = dev_get_drvdata(dev);357 int ret;358 359 if (wm8350->rtc.alarm_enabled) {360 ret = wm8350_rtc_start_alarm(wm8350);361 if (ret != 0)362 dev_err(dev, "Failed to restart RTC alarm: %d\n", ret);363 }364 365 return 0;366}367#endif368 369static int wm8350_rtc_probe(struct platform_device *pdev)370{371 struct wm8350 *wm8350 = platform_get_drvdata(pdev);372 struct wm8350_rtc *wm_rtc = &wm8350->rtc;373 int ret = 0;374 u16 timectl, power5;375 376 timectl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);377 if (timectl & WM8350_RTC_BCD) {378 dev_err(&pdev->dev, "RTC BCD mode not supported\n");379 return -EINVAL;380 }381 if (timectl & WM8350_RTC_12HR) {382 dev_err(&pdev->dev, "RTC 12 hour mode not supported\n");383 return -EINVAL;384 }385 386 /* enable the RTC if it's not already enabled */387 power5 = wm8350_reg_read(wm8350, WM8350_POWER_MGMT_5);388 if (!(power5 & WM8350_RTC_TICK_ENA)) {389 wm8350_reg_unlock(wm8350);390 391 ret = wm8350_set_bits(wm8350, WM8350_POWER_MGMT_5,392 WM8350_RTC_TICK_ENA);393 if (ret < 0) {394 dev_err(&pdev->dev, "failed to enable RTC: %d\n", ret);395 return ret;396 }397 398 wm8350_reg_lock(wm8350);399 }400 401 if (timectl & WM8350_RTC_STS) {402 int retries;403 404 ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,405 WM8350_RTC_SET);406 if (ret < 0) {407 dev_err(&pdev->dev, "failed to start: %d\n", ret);408 return ret;409 }410 411 retries = WM8350_SET_TIME_RETRIES;412 do {413 timectl = wm8350_reg_read(wm8350,414 WM8350_RTC_TIME_CONTROL);415 } while (timectl & WM8350_RTC_STS && --retries);416 417 if (retries == 0) {418 dev_err(&pdev->dev, "failed to start: timeout\n");419 return -ENODEV;420 }421 }422 423 device_init_wakeup(&pdev->dev, 1);424 425 wm_rtc->rtc = devm_rtc_device_register(&pdev->dev, "wm8350",426 &wm8350_rtc_ops, THIS_MODULE);427 if (IS_ERR(wm_rtc->rtc))428 return PTR_ERR(wm_rtc->rtc);429 430 ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_SEC,431 wm8350_rtc_update_handler, 0,432 "RTC Seconds", wm8350);433 if (ret)434 return ret;435 436 wm8350_mask_irq(wm8350, WM8350_IRQ_RTC_SEC);437 438 ret = wm8350_register_irq(wm8350, WM8350_IRQ_RTC_ALM,439 wm8350_rtc_alarm_handler, 0,440 "RTC Alarm", wm8350);441 if (ret) {442 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);443 return ret;444 }445 446 return 0;447}448 449static void wm8350_rtc_remove(struct platform_device *pdev)450{451 struct wm8350 *wm8350 = platform_get_drvdata(pdev);452 453 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_SEC, wm8350);454 wm8350_free_irq(wm8350, WM8350_IRQ_RTC_ALM, wm8350);455}456 457static SIMPLE_DEV_PM_OPS(wm8350_rtc_pm_ops, wm8350_rtc_suspend,458 wm8350_rtc_resume);459 460static struct platform_driver wm8350_rtc_driver = {461 .probe = wm8350_rtc_probe,462 .remove_new = wm8350_rtc_remove,463 .driver = {464 .name = "wm8350-rtc",465 .pm = &wm8350_rtc_pm_ops,466 },467};468 469module_platform_driver(wm8350_rtc_driver);470 471MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");472MODULE_DESCRIPTION("RTC driver for the WM8350");473MODULE_LICENSE("GPL");474MODULE_ALIAS("platform:wm8350-rtc");475