linux/drivers/rtc/rtc-da9055.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Real time clock driver for DA9055
   4 *
   5 * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6 *
   7 * Author: Dajun Dajun Chen <dajun.chen@diasemi.com>
   8 */
   9
  10#include <linux/module.h>
  11#include <linux/platform_device.h>
  12#include <linux/rtc.h>
  13
  14#include <linux/mfd/da9055/core.h>
  15#include <linux/mfd/da9055/reg.h>
  16#include <linux/mfd/da9055/pdata.h>
  17
  18struct da9055_rtc {
  19        struct rtc_device *rtc;
  20        struct da9055 *da9055;
  21        int alarm_enable;
  22};
  23
  24static int da9055_rtc_enable_alarm(struct da9055_rtc *rtc, bool enable)
  25{
  26        int ret;
  27        if (enable) {
  28                ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
  29                                        DA9055_RTC_ALM_EN,
  30                                        DA9055_RTC_ALM_EN);
  31                if (ret != 0)
  32                        dev_err(rtc->da9055->dev, "Failed to enable ALM: %d\n",
  33                                ret);
  34                rtc->alarm_enable = 1;
  35        } else {
  36                ret = da9055_reg_update(rtc->da9055, DA9055_REG_ALARM_Y,
  37                                        DA9055_RTC_ALM_EN, 0);
  38                if (ret != 0)
  39                        dev_err(rtc->da9055->dev,
  40                                "Failed to disable ALM: %d\n", ret);
  41                rtc->alarm_enable = 0;
  42        }
  43        return ret;
  44}
  45
  46static irqreturn_t da9055_rtc_alm_irq(int irq, void *data)
  47{
  48        struct da9055_rtc *rtc = data;
  49
  50        da9055_rtc_enable_alarm(rtc, 0);
  51        rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
  52
  53        return IRQ_HANDLED;
  54}
  55
  56static int da9055_read_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
  57{
  58        int ret;
  59        uint8_t v[5];
  60
  61        ret = da9055_group_read(da9055, DA9055_REG_ALARM_MI, 5, v);
  62        if (ret != 0) {
  63                dev_err(da9055->dev, "Failed to group read ALM: %d\n", ret);
  64                return ret;
  65        }
  66
  67        rtc_tm->tm_year = (v[4] & DA9055_RTC_ALM_YEAR) + 100;
  68        rtc_tm->tm_mon  = (v[3] & DA9055_RTC_ALM_MONTH) - 1;
  69        rtc_tm->tm_mday = v[2] & DA9055_RTC_ALM_DAY;
  70        rtc_tm->tm_hour = v[1] & DA9055_RTC_ALM_HOUR;
  71        rtc_tm->tm_min  = v[0] & DA9055_RTC_ALM_MIN;
  72        rtc_tm->tm_sec = 0;
  73
  74        return rtc_valid_tm(rtc_tm);
  75}
  76
  77static int da9055_set_alarm(struct da9055 *da9055, struct rtc_time *rtc_tm)
  78{
  79        int ret;
  80        uint8_t v[2];
  81
  82        rtc_tm->tm_year -= 100;
  83        rtc_tm->tm_mon += 1;
  84
  85        ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MI,
  86                                DA9055_RTC_ALM_MIN, rtc_tm->tm_min);
  87        if (ret != 0) {
  88                dev_err(da9055->dev, "Failed to write ALRM MIN: %d\n", ret);
  89                return ret;
  90        }
  91
  92        v[0] = rtc_tm->tm_hour;
  93        v[1] = rtc_tm->tm_mday;
  94
  95        ret = da9055_group_write(da9055, DA9055_REG_ALARM_H, 2, v);
  96        if (ret < 0)
  97                return ret;
  98
  99        ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
 100                                DA9055_RTC_ALM_MONTH, rtc_tm->tm_mon);
 101        if (ret < 0)
 102                dev_err(da9055->dev, "Failed to write ALM Month:%d\n", ret);
 103
 104        ret = da9055_reg_update(da9055, DA9055_REG_ALARM_Y,
 105                                DA9055_RTC_ALM_YEAR, rtc_tm->tm_year);
 106        if (ret < 0)
 107                dev_err(da9055->dev, "Failed to write ALM Year:%d\n", ret);
 108
 109        return ret;
 110}
 111
 112static int da9055_rtc_get_alarm_status(struct da9055 *da9055)
 113{
 114        int ret;
 115
 116        ret = da9055_reg_read(da9055, DA9055_REG_ALARM_Y);
 117        if (ret < 0) {
 118                dev_err(da9055->dev, "Failed to read ALM: %d\n", ret);
 119                return ret;
 120        }
 121        ret &= DA9055_RTC_ALM_EN;
 122        return (ret > 0) ? 1 : 0;
 123}
 124
 125static int da9055_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
 126{
 127        struct da9055_rtc *rtc = dev_get_drvdata(dev);
 128        uint8_t v[6];
 129        int ret;
 130
 131        ret = da9055_reg_read(rtc->da9055, DA9055_REG_COUNT_S);
 132        if (ret < 0)
 133                return ret;
 134
 135        /*
 136         * Registers are only valid when RTC_READ
 137         * status bit is asserted
 138         */
 139        if (!(ret & DA9055_RTC_READ))
 140                return -EBUSY;
 141
 142        ret = da9055_group_read(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
 143        if (ret < 0) {
 144                dev_err(rtc->da9055->dev, "Failed to read RTC time : %d\n",
 145                        ret);
 146                return ret;
 147        }
 148
 149        rtc_tm->tm_year = (v[5] & DA9055_RTC_YEAR) + 100;
 150        rtc_tm->tm_mon  = (v[4] & DA9055_RTC_MONTH) - 1;
 151        rtc_tm->tm_mday = v[3] & DA9055_RTC_DAY;
 152        rtc_tm->tm_hour = v[2] & DA9055_RTC_HOUR;
 153        rtc_tm->tm_min  = v[1] & DA9055_RTC_MIN;
 154        rtc_tm->tm_sec  = v[0] & DA9055_RTC_SEC;
 155
 156        return 0;
 157}
 158
 159static int da9055_rtc_set_time(struct device *dev, struct rtc_time *tm)
 160{
 161        struct da9055_rtc *rtc;
 162        uint8_t v[6];
 163
 164        rtc = dev_get_drvdata(dev);
 165
 166        v[0] = tm->tm_sec;
 167        v[1] = tm->tm_min;
 168        v[2] = tm->tm_hour;
 169        v[3] = tm->tm_mday;
 170        v[4] = tm->tm_mon + 1;
 171        v[5] = tm->tm_year - 100;
 172
 173        return da9055_group_write(rtc->da9055, DA9055_REG_COUNT_S, 6, v);
 174}
 175
 176static int da9055_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 177{
 178        int ret;
 179        struct rtc_time *tm = &alrm->time;
 180        struct da9055_rtc *rtc = dev_get_drvdata(dev);
 181
 182        ret = da9055_read_alarm(rtc->da9055, tm);
 183
 184        if (ret)
 185                return ret;
 186
 187        alrm->enabled = da9055_rtc_get_alarm_status(rtc->da9055);
 188
 189        return 0;
 190}
 191
 192static int da9055_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 193{
 194        int ret;
 195        struct rtc_time *tm = &alrm->time;
 196        struct da9055_rtc *rtc = dev_get_drvdata(dev);
 197
 198        ret = da9055_rtc_enable_alarm(rtc, 0);
 199        if (ret < 0)
 200                return ret;
 201
 202        ret = da9055_set_alarm(rtc->da9055, tm);
 203        if (ret)
 204                return ret;
 205
 206        ret = da9055_rtc_enable_alarm(rtc, 1);
 207
 208        return ret;
 209}
 210
 211static int da9055_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 212{
 213        struct da9055_rtc *rtc = dev_get_drvdata(dev);
 214
 215        return da9055_rtc_enable_alarm(rtc, enabled);
 216}
 217
 218static const struct rtc_class_ops da9055_rtc_ops = {
 219        .read_time      = da9055_rtc_read_time,
 220        .set_time       = da9055_rtc_set_time,
 221        .read_alarm     = da9055_rtc_read_alarm,
 222        .set_alarm      = da9055_rtc_set_alarm,
 223        .alarm_irq_enable = da9055_rtc_alarm_irq_enable,
 224};
 225
 226static int da9055_rtc_device_init(struct da9055 *da9055,
 227                                        struct da9055_pdata *pdata)
 228{
 229        int ret;
 230
 231        /* Enable RTC and the internal Crystal */
 232        ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
 233                                DA9055_RTC_EN, DA9055_RTC_EN);
 234        if (ret < 0)
 235                return ret;
 236        ret = da9055_reg_update(da9055, DA9055_REG_EN_32K,
 237                                DA9055_CRYSTAL_EN, DA9055_CRYSTAL_EN);
 238        if (ret < 0)
 239                return ret;
 240
 241        /* Enable RTC in Power Down mode */
 242        ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
 243                                DA9055_RTC_MODE_PD, DA9055_RTC_MODE_PD);
 244        if (ret < 0)
 245                return ret;
 246
 247        /* Enable RTC in Reset mode */
 248        if (pdata && pdata->reset_enable) {
 249                ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
 250                                        DA9055_RTC_MODE_SD,
 251                                        DA9055_RTC_MODE_SD <<
 252                                        DA9055_RTC_MODE_SD_SHIFT);
 253                if (ret < 0)
 254                        return ret;
 255        }
 256
 257        /* Disable the RTC TICK ALM */
 258        ret = da9055_reg_update(da9055, DA9055_REG_ALARM_MO,
 259                                DA9055_RTC_TICK_WAKE_MASK, 0);
 260        if (ret < 0)
 261                return ret;
 262
 263        return 0;
 264}
 265
 266static int da9055_rtc_probe(struct platform_device *pdev)
 267{
 268        struct da9055_rtc *rtc;
 269        struct da9055_pdata *pdata = NULL;
 270        int ret, alm_irq;
 271
 272        rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9055_rtc), GFP_KERNEL);
 273        if (!rtc)
 274                return -ENOMEM;
 275
 276        rtc->da9055 = dev_get_drvdata(pdev->dev.parent);
 277        pdata = dev_get_platdata(rtc->da9055->dev);
 278        platform_set_drvdata(pdev, rtc);
 279
 280        ret = da9055_rtc_device_init(rtc->da9055, pdata);
 281        if (ret < 0)
 282                goto err_rtc;
 283
 284        ret = da9055_reg_read(rtc->da9055, DA9055_REG_ALARM_Y);
 285        if (ret < 0)
 286                goto err_rtc;
 287
 288        if (ret & DA9055_RTC_ALM_EN)
 289                rtc->alarm_enable = 1;
 290
 291        device_init_wakeup(&pdev->dev, 1);
 292
 293        rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 294                                        &da9055_rtc_ops, THIS_MODULE);
 295        if (IS_ERR(rtc->rtc)) {
 296                ret = PTR_ERR(rtc->rtc);
 297                goto err_rtc;
 298        }
 299
 300        alm_irq = platform_get_irq_byname(pdev, "ALM");
 301        if (alm_irq < 0)
 302                return alm_irq;
 303
 304        ret = devm_request_threaded_irq(&pdev->dev, alm_irq, NULL,
 305                                        da9055_rtc_alm_irq,
 306                                        IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
 307                                        "ALM", rtc);
 308        if (ret != 0)
 309                dev_err(rtc->da9055->dev, "irq registration failed: %d\n", ret);
 310
 311err_rtc:
 312        return ret;
 313
 314}
 315
 316#ifdef CONFIG_PM
 317/* Turn off the alarm if it should not be a wake source. */
 318static int da9055_rtc_suspend(struct device *dev)
 319{
 320        struct platform_device *pdev = to_platform_device(dev);
 321        struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
 322        int ret;
 323
 324        if (!device_may_wakeup(&pdev->dev)) {
 325                /* Disable the ALM IRQ */
 326                ret = da9055_rtc_enable_alarm(rtc, 0);
 327                if (ret < 0)
 328                        dev_err(&pdev->dev, "Failed to disable RTC ALM\n");
 329        }
 330
 331        return 0;
 332}
 333
 334/* Enable the alarm if it should be enabled (in case it was disabled to
 335 * prevent use as a wake source).
 336 */
 337static int da9055_rtc_resume(struct device *dev)
 338{
 339        struct platform_device *pdev = to_platform_device(dev);
 340        struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
 341        int ret;
 342
 343        if (!device_may_wakeup(&pdev->dev)) {
 344                if (rtc->alarm_enable) {
 345                        ret = da9055_rtc_enable_alarm(rtc, 1);
 346                        if (ret < 0)
 347                                dev_err(&pdev->dev,
 348                                        "Failed to restart RTC ALM\n");
 349                }
 350        }
 351
 352        return 0;
 353}
 354
 355/* Unconditionally disable the alarm */
 356static int da9055_rtc_freeze(struct device *dev)
 357{
 358        struct platform_device *pdev = to_platform_device(dev);
 359        struct da9055_rtc *rtc = dev_get_drvdata(&pdev->dev);
 360        int ret;
 361
 362        ret = da9055_rtc_enable_alarm(rtc, 0);
 363        if (ret < 0)
 364                dev_err(&pdev->dev, "Failed to freeze RTC ALMs\n");
 365
 366        return 0;
 367
 368}
 369#else
 370#define da9055_rtc_suspend NULL
 371#define da9055_rtc_resume NULL
 372#define da9055_rtc_freeze NULL
 373#endif
 374
 375static const struct dev_pm_ops da9055_rtc_pm_ops = {
 376        .suspend = da9055_rtc_suspend,
 377        .resume = da9055_rtc_resume,
 378
 379        .freeze = da9055_rtc_freeze,
 380        .thaw = da9055_rtc_resume,
 381        .restore = da9055_rtc_resume,
 382
 383        .poweroff = da9055_rtc_suspend,
 384};
 385
 386static struct platform_driver da9055_rtc_driver = {
 387        .probe  = da9055_rtc_probe,
 388        .driver = {
 389                .name   = "da9055-rtc",
 390                .pm = &da9055_rtc_pm_ops,
 391        },
 392};
 393
 394module_platform_driver(da9055_rtc_driver);
 395
 396MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
 397MODULE_DESCRIPTION("RTC driver for Dialog DA9055 PMIC");
 398MODULE_LICENSE("GPL");
 399MODULE_ALIAS("platform:da9055-rtc");
 400