drivers/rtc/rtc-mt6397.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3 * Copyright (c) 2014-2015 MediaTek Inc.
   4 * Author: Tianping.Fang <tianping.fang@mediatek.com>
   5 */
   6
   7 #include <linux/err.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/mfd/mt6397/core.h>
  10 #include <linux/module.h>
  11 #include <linux/mutex.h>
  12 #include <linux/of_device.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15 #include <linux/rtc.h>
  16 #include <linux/mfd/mt6397/rtc.h>
  17 #include <linux/mod_devicetable.h>
  18
  19 static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
  20 {
  21         int ret;
  22         u32 data;
  23
  24         ret = regmap_write(rtc->regmap, rtc->addr_base + rtc->data->wrtgr, 1);
  25         if (ret < 0)
  26                 return ret;
  27
  28         ret = regmap_read_poll_timeout(rtc->regmap,
  29                                         rtc->addr_base + RTC_BBPU, data,
  30                                         !(data & RTC_BBPU_CBUSY),
  31                                         MTK_RTC_POLL_DELAY_US,
  32                                         MTK_RTC_POLL_TIMEOUT);
  33         if (ret < 0)
  34                 dev_err(rtc->rtc_dev->dev.parent,
  35                         "failed to write WRTGR: %d\n", ret);
  36
  37         return ret;
  38 }
  39
  40 static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
  41 {
  42         struct mt6397_rtc *rtc = data;
  43         u32 irqsta, irqen;
  44         int ret;
  45
  46         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
  47         if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
  48                 rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
  49                 irqen = irqsta & ~RTC_IRQ_EN_AL;
  50                 mutex_lock(&rtc->lock);
  51                 if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
  52                                  irqen) == 0)
  53                         mtk_rtc_write_trigger(rtc);
  54                 mutex_unlock(&rtc->lock);
  55
  56                 return IRQ_HANDLED;
  57         }
  58
  59         return IRQ_NONE;
  60 }
  61
  62 static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
  63                                struct rtc_time *tm, int *sec)
  64 {
  65         int ret;
  66         u16 data[RTC_OFFSET_COUNT];
  67
  68         mutex_lock(&rtc->lock);
  69         ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
  70                                data, RTC_OFFSET_COUNT);
  71         if (ret < 0)
  72                 goto exit;
  73
  74         tm->tm_sec = data[RTC_OFFSET_SEC];
  75         tm->tm_min = data[RTC_OFFSET_MIN];
  76         tm->tm_hour = data[RTC_OFFSET_HOUR];
  77         tm->tm_mday = data[RTC_OFFSET_DOM];
  78         tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
  79         tm->tm_year = data[RTC_OFFSET_YEAR];
  80
  81         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
  82 exit:
  83         mutex_unlock(&rtc->lock);
  84         return ret;
  85 }
  86
  87 static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
  88 {
  89         time64_t time;
  90         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
  91         int days, sec, ret;
  92
  93         do {
  94                 ret = __mtk_rtc_read_time(rtc, tm, &sec);
  95                 if (ret < 0)
  96                         goto exit;
  97         } while (sec < tm->tm_sec);
  98
  99         /* HW register use 7 bits to store year data, minus
 100          * RTC_MIN_YEAR_OFFSET before write year data to register, and plus
 101          * RTC_MIN_YEAR_OFFSET back after read year from register
 102          */
 103         tm->tm_year += RTC_MIN_YEAR_OFFSET;
 104
 105         /* HW register start mon from one, but tm_mon start from zero. */
 106         tm->tm_mon--;
 107         time = rtc_tm_to_time64(tm);
 108
 109         /* rtc_tm_to_time64 covert Gregorian date to seconds since
 110          * 01-01-1970 00:00:00, and this date is Thursday.
 111          */
 112         days = div_s64(time, 86400);
 113         tm->tm_wday = (days + 4) % 7;
 114
 115 exit:
 116         return ret;
 117 }
 118
 119 static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
 120 {
 121         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 122         int ret;
 123         u16 data[RTC_OFFSET_COUNT];
 124
 125         tm->tm_year -= RTC_MIN_YEAR_OFFSET;
 126         tm->tm_mon++;
 127
 128         data[RTC_OFFSET_SEC] = tm->tm_sec;
 129         data[RTC_OFFSET_MIN] = tm->tm_min;
 130         data[RTC_OFFSET_HOUR] = tm->tm_hour;
 131         data[RTC_OFFSET_DOM] = tm->tm_mday;
 132         data[RTC_OFFSET_MTH] = tm->tm_mon;
 133         data[RTC_OFFSET_YEAR] = tm->tm_year;
 134
 135         mutex_lock(&rtc->lock);
 136         ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
 137                                 data, RTC_OFFSET_COUNT);
 138         if (ret < 0)
 139                 goto exit;
 140
 141         /* Time register write to hardware after call trigger function */
 142         ret = mtk_rtc_write_trigger(rtc);
 143
 144 exit:
 145         mutex_unlock(&rtc->lock);
 146         return ret;
 147 }
 148
 149 static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
 150 {
 151         struct rtc_time *tm = &alm->time;
 152         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 153         u32 irqen, pdn2;
 154         int ret;
 155         u16 data[RTC_OFFSET_COUNT];
 156
 157         mutex_lock(&rtc->lock);
 158         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
 159         if (ret < 0)
 160                 goto err_exit;
 161         ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
 162         if (ret < 0)
 163                 goto err_exit;
 164
 165         ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
 166                                data, RTC_OFFSET_COUNT);
 167         if (ret < 0)
 168                 goto err_exit;
 169
 170         alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
 171         alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
 172         mutex_unlock(&rtc->lock);
 173
 174         tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
 175         tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
 176         tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
 177         tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
 178         tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
 179         tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
 180
 181         tm->tm_year += RTC_MIN_YEAR_OFFSET;
 182         tm->tm_mon--;
 183
 184         return 0;
 185 err_exit:
 186         mutex_unlock(&rtc->lock);
 187         return ret;
 188 }
 189
 190 static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
 191 {
 192         struct rtc_time *tm = &alm->time;
 193         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 194         int ret;
 195         u16 data[RTC_OFFSET_COUNT];
 196
 197         tm->tm_year -= RTC_MIN_YEAR_OFFSET;
 198         tm->tm_mon++;
 199
 200         mutex_lock(&rtc->lock);
 201         ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
 202                                data, RTC_OFFSET_COUNT);
 203         if (ret < 0)
 204                 goto exit;
 205
 206         data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
 207                                 (tm->tm_sec & RTC_AL_SEC_MASK));
 208         data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
 209                                 (tm->tm_min & RTC_AL_MIN_MASK));
 210         data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
 211                                 (tm->tm_hour & RTC_AL_HOU_MASK));
 212         data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
 213                                 (tm->tm_mday & RTC_AL_DOM_MASK));
 214         data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
 215                                 (tm->tm_mon & RTC_AL_MTH_MASK));
 216         data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
 217                                 (tm->tm_year & RTC_AL_YEA_MASK));
 218
 219         if (alm->enabled) {
 220                 ret = regmap_bulk_write(rtc->regmap,
 221                                         rtc->addr_base + RTC_AL_SEC,
 222                                         data, RTC_OFFSET_COUNT);
 223                 if (ret < 0)
 224                         goto exit;
 225                 ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
 226                                    RTC_AL_MASK_DOW);
 227                 if (ret < 0)
 228                         goto exit;
 229                 ret = regmap_update_bits(rtc->regmap,
 230                                          rtc->addr_base + RTC_IRQ_EN,
 231                                          RTC_IRQ_EN_ONESHOT_AL,
 232                                          RTC_IRQ_EN_ONESHOT_AL);
 233                 if (ret < 0)
 234                         goto exit;
 235         } else {
 236                 ret = regmap_update_bits(rtc->regmap,
 237                                          rtc->addr_base + RTC_IRQ_EN,
 238                                          RTC_IRQ_EN_ONESHOT_AL, 0);
 239                 if (ret < 0)
 240                         goto exit;
 241         }
 242
 243         /* All alarm time register write to hardware after calling
 244          * mtk_rtc_write_trigger. This can avoid race condition if alarm
 245          * occur happen during writing alarm time register.
 246          */
 247         ret = mtk_rtc_write_trigger(rtc);
 248 exit:
 249         mutex_unlock(&rtc->lock);
 250         return ret;
 251 }
 252
 253 static const struct rtc_class_ops mtk_rtc_ops = {
 254         .read_time  = mtk_rtc_read_time,
 255         .set_time   = mtk_rtc_set_time,
 256         .read_alarm = mtk_rtc_read_alarm,
 257         .set_alarm  = mtk_rtc_set_alarm,
 258 };
 259
 260 static int mtk_rtc_probe(struct platform_device *pdev)
 261 {
 262         struct resource *res;
 263         struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
 264         struct mt6397_rtc *rtc;
 265         int ret;
 266
 267         rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
 268         if (!rtc)
 269                 return -ENOMEM;
 270
 271         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 272         rtc->addr_base = res->start;
 273
 274         rtc->data = of_device_get_match_data(&pdev->dev);
 275
 276         rtc->irq = platform_get_irq(pdev, 0);
 277         if (rtc->irq < 0)
 278                 return rtc->irq;
 279
 280         rtc->regmap = mt6397_chip->regmap;
 281         mutex_init(&rtc->lock);
 282
 283         platform_set_drvdata(pdev, rtc);
 284
 285         rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
 286         if (IS_ERR(rtc->rtc_dev))
 287                 return PTR_ERR(rtc->rtc_dev);
 288
 289         ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
 290                                         mtk_rtc_irq_handler_thread,
 291                                         IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
 292                                         "mt6397-rtc", rtc);
 293
 294         if (ret) {
 295                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
 296                         rtc->irq, ret);
 297                 return ret;
 298         }
 299
 300         device_init_wakeup(&pdev->dev, 1);
 301
 302         rtc->rtc_dev->ops = &mtk_rtc_ops;
 303
 304         return devm_rtc_register_device(rtc->rtc_dev);
 305 }
 306
 307 #ifdef CONFIG_PM_SLEEP
 308 static int mt6397_rtc_suspend(struct device *dev)
 309 {
 310         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 311
 312         if (device_may_wakeup(dev))
 313                 enable_irq_wake(rtc->irq);
 314
 315         return 0;
 316 }
 317
 318 static int mt6397_rtc_resume(struct device *dev)
 319 {
 320         struct mt6397_rtc *rtc = dev_get_drvdata(dev);
 321
 322         if (device_may_wakeup(dev))
 323                 disable_irq_wake(rtc->irq);
 324
 325         return 0;
 326 }
 327 #endif
 328
 329 static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
 330                         mt6397_rtc_resume);
 331
 332 static const struct mtk_rtc_data mt6358_rtc_data = {
 333         .wrtgr = RTC_WRTGR_MT6358,
 334 };
 335
 336 static const struct mtk_rtc_data mt6397_rtc_data = {
 337         .wrtgr = RTC_WRTGR_MT6397,
 338 };
 339
 340 static const struct of_device_id mt6397_rtc_of_match[] = {
 341         { .compatible = "mediatek,mt6323-rtc", .data = &mt6397_rtc_data },
 342         { .compatible = "mediatek,mt6358-rtc", .data = &mt6358_rtc_data },
 343         { .compatible = "mediatek,mt6397-rtc", .data = &mt6397_rtc_data },
 344         { }
 345 };
 346 MODULE_DEVICE_TABLE(of, mt6397_rtc_of_match);
 347
 348 static struct platform_driver mtk_rtc_driver = {
 349         .driver = {
 350                 .name = "mt6397-rtc",
 351                 .of_match_table = mt6397_rtc_of_match,
 352                 .pm = &mt6397_pm_ops,
 353         },
 354         .probe  = mtk_rtc_probe,
 355 };
 356
 357 module_platform_driver(mtk_rtc_driver);
 358
 359 MODULE_LICENSE("GPL v2");
 360 MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
 361 MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");