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1// SPDX-License-Identifier: GPL-2.0-only2/* drivers/rtc/rtc-s3c.c3 *4 * Copyright (c) 2010 Samsung Electronics Co., Ltd.5 * http://www.samsung.com/6 *7 * Copyright (c) 2004,2006 Simtec Electronics8 * Ben Dooks, <ben@simtec.co.uk>9 * http://armlinux.simtec.co.uk/10 *11 * S3C2410/S3C2440/S3C24XX Internal RTC Driver12*/13 14#include <linux/module.h>15#include <linux/fs.h>16#include <linux/string.h>17#include <linux/init.h>18#include <linux/platform_device.h>19#include <linux/interrupt.h>20#include <linux/rtc.h>21#include <linux/bcd.h>22#include <linux/clk.h>23#include <linux/log2.h>24#include <linux/slab.h>25#include <linux/of.h>26#include <linux/uaccess.h>27#include <linux/io.h>28 29#include <asm/irq.h>30#include "rtc-s3c.h"31 32struct s3c_rtc {33 struct device *dev;34 struct rtc_device *rtc;35 36 void __iomem *base;37 struct clk *rtc_clk;38 struct clk *rtc_src_clk;39 bool alarm_enabled;40 41 const struct s3c_rtc_data *data;42 43 int irq_alarm;44 spinlock_t alarm_lock;45 46 bool wake_en;47};48 49struct s3c_rtc_data {50 bool needs_src_clk;51 52 void (*irq_handler) (struct s3c_rtc *info, int mask);53 void (*enable) (struct s3c_rtc *info);54 void (*disable) (struct s3c_rtc *info);55};56 57static int s3c_rtc_enable_clk(struct s3c_rtc *info)58{59 int ret;60 61 ret = clk_enable(info->rtc_clk);62 if (ret)63 return ret;64 65 if (info->data->needs_src_clk) {66 ret = clk_enable(info->rtc_src_clk);67 if (ret) {68 clk_disable(info->rtc_clk);69 return ret;70 }71 }72 return 0;73}74 75static void s3c_rtc_disable_clk(struct s3c_rtc *info)76{77 if (info->data->needs_src_clk)78 clk_disable(info->rtc_src_clk);79 clk_disable(info->rtc_clk);80}81 82/* IRQ Handler */83static irqreturn_t s3c_rtc_alarmirq(int irq, void *id)84{85 struct s3c_rtc *info = (struct s3c_rtc *)id;86 87 if (info->data->irq_handler)88 info->data->irq_handler(info, S3C2410_INTP_ALM);89 90 return IRQ_HANDLED;91}92 93/* Update control registers */94static int s3c_rtc_setaie(struct device *dev, unsigned int enabled)95{96 struct s3c_rtc *info = dev_get_drvdata(dev);97 unsigned long flags;98 unsigned int tmp;99 int ret;100 101 dev_dbg(info->dev, "%s: aie=%d\n", __func__, enabled);102 103 ret = s3c_rtc_enable_clk(info);104 if (ret)105 return ret;106 107 tmp = readb(info->base + S3C2410_RTCALM) & ~S3C2410_RTCALM_ALMEN;108 109 if (enabled)110 tmp |= S3C2410_RTCALM_ALMEN;111 112 writeb(tmp, info->base + S3C2410_RTCALM);113 114 spin_lock_irqsave(&info->alarm_lock, flags);115 116 if (info->alarm_enabled && !enabled)117 s3c_rtc_disable_clk(info);118 else if (!info->alarm_enabled && enabled)119 ret = s3c_rtc_enable_clk(info);120 121 info->alarm_enabled = enabled;122 spin_unlock_irqrestore(&info->alarm_lock, flags);123 124 s3c_rtc_disable_clk(info);125 126 return ret;127}128 129/* Read time from RTC and convert it from BCD */130static int s3c_rtc_read_time(struct s3c_rtc *info, struct rtc_time *tm)131{132 unsigned int have_retried = 0;133 int ret;134 135 ret = s3c_rtc_enable_clk(info);136 if (ret)137 return ret;138 139retry_get_time:140 tm->tm_min = readb(info->base + S3C2410_RTCMIN);141 tm->tm_hour = readb(info->base + S3C2410_RTCHOUR);142 tm->tm_mday = readb(info->base + S3C2410_RTCDATE);143 tm->tm_mon = readb(info->base + S3C2410_RTCMON);144 tm->tm_year = readb(info->base + S3C2410_RTCYEAR);145 tm->tm_sec = readb(info->base + S3C2410_RTCSEC);146 147 /*148 * The only way to work out whether the system was mid-update149 * when we read it is to check the second counter, and if it150 * is zero, then we re-try the entire read151 */152 if (tm->tm_sec == 0 && !have_retried) {153 have_retried = 1;154 goto retry_get_time;155 }156 157 s3c_rtc_disable_clk(info);158 159 tm->tm_sec = bcd2bin(tm->tm_sec);160 tm->tm_min = bcd2bin(tm->tm_min);161 tm->tm_hour = bcd2bin(tm->tm_hour);162 tm->tm_mday = bcd2bin(tm->tm_mday);163 tm->tm_mon = bcd2bin(tm->tm_mon);164 tm->tm_year = bcd2bin(tm->tm_year);165 166 return 0;167}168 169/* Convert time to BCD and write it to RTC */170static int s3c_rtc_write_time(struct s3c_rtc *info, const struct rtc_time *tm)171{172 int ret;173 174 ret = s3c_rtc_enable_clk(info);175 if (ret)176 return ret;177 178 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_RTCSEC);179 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_RTCMIN);180 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_RTCHOUR);181 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_RTCDATE);182 writeb(bin2bcd(tm->tm_mon), info->base + S3C2410_RTCMON);183 writeb(bin2bcd(tm->tm_year), info->base + S3C2410_RTCYEAR);184 185 s3c_rtc_disable_clk(info);186 187 return 0;188}189 190static int s3c_rtc_gettime(struct device *dev, struct rtc_time *tm)191{192 struct s3c_rtc *info = dev_get_drvdata(dev);193 int ret;194 195 ret = s3c_rtc_read_time(info, tm);196 if (ret)197 return ret;198 199 /* Convert internal representation to actual date/time */200 tm->tm_year += 100;201 tm->tm_mon -= 1;202 203 dev_dbg(dev, "read time %ptR\n", tm);204 return 0;205}206 207static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)208{209 struct s3c_rtc *info = dev_get_drvdata(dev);210 struct rtc_time rtc_tm = *tm;211 212 dev_dbg(dev, "set time %ptR\n", tm);213 214 /*215 * Convert actual date/time to internal representation.216 * We get around Y2K by simply not supporting it.217 */218 rtc_tm.tm_year -= 100;219 rtc_tm.tm_mon += 1;220 221 return s3c_rtc_write_time(info, &rtc_tm);222}223 224static int s3c_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)225{226 struct s3c_rtc *info = dev_get_drvdata(dev);227 struct rtc_time *alm_tm = &alrm->time;228 unsigned int alm_en;229 int ret;230 231 ret = s3c_rtc_enable_clk(info);232 if (ret)233 return ret;234 235 alm_tm->tm_sec = readb(info->base + S3C2410_ALMSEC);236 alm_tm->tm_min = readb(info->base + S3C2410_ALMMIN);237 alm_tm->tm_hour = readb(info->base + S3C2410_ALMHOUR);238 alm_tm->tm_mon = readb(info->base + S3C2410_ALMMON);239 alm_tm->tm_mday = readb(info->base + S3C2410_ALMDATE);240 alm_tm->tm_year = readb(info->base + S3C2410_ALMYEAR);241 242 alm_en = readb(info->base + S3C2410_RTCALM);243 244 s3c_rtc_disable_clk(info);245 246 alrm->enabled = (alm_en & S3C2410_RTCALM_ALMEN) ? 1 : 0;247 248 dev_dbg(dev, "read alarm %d, %ptR\n", alm_en, alm_tm);249 250 /* decode the alarm enable field */251 if (alm_en & S3C2410_RTCALM_SECEN)252 alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);253 254 if (alm_en & S3C2410_RTCALM_MINEN)255 alm_tm->tm_min = bcd2bin(alm_tm->tm_min);256 257 if (alm_en & S3C2410_RTCALM_HOUREN)258 alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);259 260 if (alm_en & S3C2410_RTCALM_DAYEN)261 alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);262 263 if (alm_en & S3C2410_RTCALM_MONEN) {264 alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);265 alm_tm->tm_mon -= 1;266 }267 268 if (alm_en & S3C2410_RTCALM_YEAREN)269 alm_tm->tm_year = bcd2bin(alm_tm->tm_year);270 271 return 0;272}273 274static int s3c_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)275{276 struct s3c_rtc *info = dev_get_drvdata(dev);277 struct rtc_time *tm = &alrm->time;278 unsigned int alrm_en;279 int ret;280 281 dev_dbg(dev, "s3c_rtc_setalarm: %d, %ptR\n", alrm->enabled, tm);282 283 ret = s3c_rtc_enable_clk(info);284 if (ret)285 return ret;286 287 alrm_en = readb(info->base + S3C2410_RTCALM) & S3C2410_RTCALM_ALMEN;288 writeb(0x00, info->base + S3C2410_RTCALM);289 290 if (tm->tm_sec < 60 && tm->tm_sec >= 0) {291 alrm_en |= S3C2410_RTCALM_SECEN;292 writeb(bin2bcd(tm->tm_sec), info->base + S3C2410_ALMSEC);293 }294 295 if (tm->tm_min < 60 && tm->tm_min >= 0) {296 alrm_en |= S3C2410_RTCALM_MINEN;297 writeb(bin2bcd(tm->tm_min), info->base + S3C2410_ALMMIN);298 }299 300 if (tm->tm_hour < 24 && tm->tm_hour >= 0) {301 alrm_en |= S3C2410_RTCALM_HOUREN;302 writeb(bin2bcd(tm->tm_hour), info->base + S3C2410_ALMHOUR);303 }304 305 if (tm->tm_mon < 12 && tm->tm_mon >= 0) {306 alrm_en |= S3C2410_RTCALM_MONEN;307 writeb(bin2bcd(tm->tm_mon + 1), info->base + S3C2410_ALMMON);308 }309 310 if (tm->tm_mday <= 31 && tm->tm_mday >= 1) {311 alrm_en |= S3C2410_RTCALM_DAYEN;312 writeb(bin2bcd(tm->tm_mday), info->base + S3C2410_ALMDATE);313 }314 315 dev_dbg(dev, "setting S3C2410_RTCALM to %08x\n", alrm_en);316 317 writeb(alrm_en, info->base + S3C2410_RTCALM);318 319 s3c_rtc_setaie(dev, alrm->enabled);320 321 s3c_rtc_disable_clk(info);322 323 return 0;324}325 326static const struct rtc_class_ops s3c_rtcops = {327 .read_time = s3c_rtc_gettime,328 .set_time = s3c_rtc_settime,329 .read_alarm = s3c_rtc_getalarm,330 .set_alarm = s3c_rtc_setalarm,331 .alarm_irq_enable = s3c_rtc_setaie,332};333 334static void s3c24xx_rtc_enable(struct s3c_rtc *info)335{336 unsigned int con, tmp;337 338 con = readw(info->base + S3C2410_RTCCON);339 /* re-enable the device, and check it is ok */340 if ((con & S3C2410_RTCCON_RTCEN) == 0) {341 dev_info(info->dev, "rtc disabled, re-enabling\n");342 343 tmp = readw(info->base + S3C2410_RTCCON);344 writew(tmp | S3C2410_RTCCON_RTCEN, info->base + S3C2410_RTCCON);345 }346 347 if (con & S3C2410_RTCCON_CNTSEL) {348 dev_info(info->dev, "removing RTCCON_CNTSEL\n");349 350 tmp = readw(info->base + S3C2410_RTCCON);351 writew(tmp & ~S3C2410_RTCCON_CNTSEL,352 info->base + S3C2410_RTCCON);353 }354 355 if (con & S3C2410_RTCCON_CLKRST) {356 dev_info(info->dev, "removing RTCCON_CLKRST\n");357 358 tmp = readw(info->base + S3C2410_RTCCON);359 writew(tmp & ~S3C2410_RTCCON_CLKRST,360 info->base + S3C2410_RTCCON);361 }362}363 364static void s3c24xx_rtc_disable(struct s3c_rtc *info)365{366 unsigned int con;367 368 con = readw(info->base + S3C2410_RTCCON);369 con &= ~S3C2410_RTCCON_RTCEN;370 writew(con, info->base + S3C2410_RTCCON);371 372 con = readb(info->base + S3C2410_TICNT);373 con &= ~S3C2410_TICNT_ENABLE;374 writeb(con, info->base + S3C2410_TICNT);375}376 377static void s3c6410_rtc_disable(struct s3c_rtc *info)378{379 unsigned int con;380 381 con = readw(info->base + S3C2410_RTCCON);382 con &= ~S3C64XX_RTCCON_TICEN;383 con &= ~S3C2410_RTCCON_RTCEN;384 writew(con, info->base + S3C2410_RTCCON);385}386 387static void s3c_rtc_remove(struct platform_device *pdev)388{389 struct s3c_rtc *info = platform_get_drvdata(pdev);390 391 s3c_rtc_setaie(info->dev, 0);392 393 if (info->data->needs_src_clk)394 clk_unprepare(info->rtc_src_clk);395 clk_unprepare(info->rtc_clk);396}397 398static int s3c_rtc_probe(struct platform_device *pdev)399{400 struct s3c_rtc *info = NULL;401 int ret;402 403 info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);404 if (!info)405 return -ENOMEM;406 407 info->dev = &pdev->dev;408 info->data = of_device_get_match_data(&pdev->dev);409 if (!info->data) {410 dev_err(&pdev->dev, "failed getting s3c_rtc_data\n");411 return -EINVAL;412 }413 spin_lock_init(&info->alarm_lock);414 415 platform_set_drvdata(pdev, info);416 417 info->irq_alarm = platform_get_irq(pdev, 0);418 if (info->irq_alarm < 0)419 return info->irq_alarm;420 421 dev_dbg(&pdev->dev, "s3c2410_rtc: alarm irq %d\n", info->irq_alarm);422 423 /* get the memory region */424 info->base = devm_platform_ioremap_resource(pdev, 0);425 if (IS_ERR(info->base))426 return PTR_ERR(info->base);427 428 info->rtc_clk = devm_clk_get(&pdev->dev, "rtc");429 if (IS_ERR(info->rtc_clk))430 return dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_clk),431 "failed to find rtc clock\n");432 ret = clk_prepare_enable(info->rtc_clk);433 if (ret)434 return ret;435 436 if (info->data->needs_src_clk) {437 info->rtc_src_clk = devm_clk_get(&pdev->dev, "rtc_src");438 if (IS_ERR(info->rtc_src_clk)) {439 ret = dev_err_probe(&pdev->dev, PTR_ERR(info->rtc_src_clk),440 "failed to find rtc source clock\n");441 goto err_src_clk;442 }443 ret = clk_prepare_enable(info->rtc_src_clk);444 if (ret)445 goto err_src_clk;446 }447 448 /* disable RTC enable bits potentially set by the bootloader */449 if (info->data->disable)450 info->data->disable(info);451 452 /* check to see if everything is setup correctly */453 if (info->data->enable)454 info->data->enable(info);455 456 dev_dbg(&pdev->dev, "s3c2410_rtc: RTCCON=%02x\n",457 readw(info->base + S3C2410_RTCCON));458 459 device_init_wakeup(&pdev->dev, 1);460 461 info->rtc = devm_rtc_allocate_device(&pdev->dev);462 if (IS_ERR(info->rtc)) {463 ret = PTR_ERR(info->rtc);464 goto err_nortc;465 }466 467 info->rtc->ops = &s3c_rtcops;468 info->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;469 info->rtc->range_max = RTC_TIMESTAMP_END_2099;470 471 ret = devm_rtc_register_device(info->rtc);472 if (ret)473 goto err_nortc;474 475 ret = devm_request_irq(&pdev->dev, info->irq_alarm, s3c_rtc_alarmirq,476 0, "s3c2410-rtc alarm", info);477 if (ret) {478 dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_alarm, ret);479 goto err_nortc;480 }481 482 s3c_rtc_disable_clk(info);483 484 return 0;485 486err_nortc:487 if (info->data->disable)488 info->data->disable(info);489 490 if (info->data->needs_src_clk)491 clk_disable_unprepare(info->rtc_src_clk);492err_src_clk:493 clk_disable_unprepare(info->rtc_clk);494 495 return ret;496}497 498#ifdef CONFIG_PM_SLEEP499 500static int s3c_rtc_suspend(struct device *dev)501{502 struct s3c_rtc *info = dev_get_drvdata(dev);503 int ret;504 505 ret = s3c_rtc_enable_clk(info);506 if (ret)507 return ret;508 509 if (info->data->disable)510 info->data->disable(info);511 512 if (device_may_wakeup(dev) && !info->wake_en) {513 if (enable_irq_wake(info->irq_alarm) == 0)514 info->wake_en = true;515 else516 dev_err(dev, "enable_irq_wake failed\n");517 }518 519 return 0;520}521 522static int s3c_rtc_resume(struct device *dev)523{524 struct s3c_rtc *info = dev_get_drvdata(dev);525 526 if (info->data->enable)527 info->data->enable(info);528 529 s3c_rtc_disable_clk(info);530 531 if (device_may_wakeup(dev) && info->wake_en) {532 disable_irq_wake(info->irq_alarm);533 info->wake_en = false;534 }535 536 return 0;537}538#endif539static SIMPLE_DEV_PM_OPS(s3c_rtc_pm_ops, s3c_rtc_suspend, s3c_rtc_resume);540 541static void s3c24xx_rtc_irq(struct s3c_rtc *info, int mask)542{543 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);544}545 546static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)547{548 rtc_update_irq(info->rtc, 1, RTC_AF | RTC_IRQF);549 writeb(mask, info->base + S3C2410_INTP);550}551 552static struct s3c_rtc_data const s3c2410_rtc_data = {553 .irq_handler = s3c24xx_rtc_irq,554 .enable = s3c24xx_rtc_enable,555 .disable = s3c24xx_rtc_disable,556};557 558static struct s3c_rtc_data const s3c2416_rtc_data = {559 .irq_handler = s3c24xx_rtc_irq,560 .enable = s3c24xx_rtc_enable,561 .disable = s3c24xx_rtc_disable,562};563 564static struct s3c_rtc_data const s3c2443_rtc_data = {565 .irq_handler = s3c24xx_rtc_irq,566 .enable = s3c24xx_rtc_enable,567 .disable = s3c24xx_rtc_disable,568};569 570static struct s3c_rtc_data const s3c6410_rtc_data = {571 .needs_src_clk = true,572 .irq_handler = s3c6410_rtc_irq,573 .enable = s3c24xx_rtc_enable,574 .disable = s3c6410_rtc_disable,575};576 577static const __maybe_unused struct of_device_id s3c_rtc_dt_match[] = {578 {579 .compatible = "samsung,s3c2410-rtc",580 .data = &s3c2410_rtc_data,581 }, {582 .compatible = "samsung,s3c2416-rtc",583 .data = &s3c2416_rtc_data,584 }, {585 .compatible = "samsung,s3c2443-rtc",586 .data = &s3c2443_rtc_data,587 }, {588 .compatible = "samsung,s3c6410-rtc",589 .data = &s3c6410_rtc_data,590 }, {591 .compatible = "samsung,exynos3250-rtc",592 .data = &s3c6410_rtc_data,593 },594 { /* sentinel */ },595};596MODULE_DEVICE_TABLE(of, s3c_rtc_dt_match);597 598static struct platform_driver s3c_rtc_driver = {599 .probe = s3c_rtc_probe,600 .remove_new = s3c_rtc_remove,601 .driver = {602 .name = "s3c-rtc",603 .pm = &s3c_rtc_pm_ops,604 .of_match_table = of_match_ptr(s3c_rtc_dt_match),605 },606};607module_platform_driver(s3c_rtc_driver);608 609MODULE_DESCRIPTION("Samsung S3C RTC Driver");610MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");611MODULE_LICENSE("GPL");612MODULE_ALIAS("platform:s3c2410-rtc");613