drivers/rtc/rtc-da9055.c

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