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