drivers/rtc/rtc-da9063.c

   1 /* rtc-da9063.c - Real time clock device driver for DA9063
   2  * Copyright (C) 2013-14  Dialog Semiconductor Ltd.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Library General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Library General Public License for more details.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/module.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/slab.h>
  22 #include <linux/delay.h>
  23 #include <linux/regmap.h>
  24 #include <linux/mfd/da9063/registers.h>
  25 #include <linux/mfd/da9063/core.h>
  26
  27 #define YEARS_TO_DA9063(year)           ((year) - 100)
  28 #define MONTHS_TO_DA9063(month)         ((month) + 1)
  29 #define YEARS_FROM_DA9063(year)         ((year) + 100)
  30 #define MONTHS_FROM_DA9063(month)       ((month) - 1)
  31
  32 #define RTC_DATA_LEN    (DA9063_REG_COUNT_Y - DA9063_REG_COUNT_S + 1)
  33 #define RTC_SEC         0
  34 #define RTC_MIN         1
  35 #define RTC_HOUR        2
  36 #define RTC_DAY         3
  37 #define RTC_MONTH       4
  38 #define RTC_YEAR        5
  39
  40 struct da9063_rtc {
  41         struct rtc_device       *rtc_dev;
  42         struct da9063           *hw;
  43         struct rtc_time         alarm_time;
  44         bool                    rtc_sync;
  45 };
  46
  47 static void da9063_data_to_tm(u8 *data, struct rtc_time *tm)
  48 {
  49         tm->tm_sec  = data[RTC_SEC]  & DA9063_COUNT_SEC_MASK;
  50         tm->tm_min  = data[RTC_MIN]  & DA9063_COUNT_MIN_MASK;
  51         tm->tm_hour = data[RTC_HOUR] & DA9063_COUNT_HOUR_MASK;
  52         tm->tm_mday = data[RTC_DAY]  & DA9063_COUNT_DAY_MASK;
  53         tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
  54                                          DA9063_COUNT_MONTH_MASK);
  55         tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
  56                                         DA9063_COUNT_YEAR_MASK);
  57 }
  58
  59 static void da9063_tm_to_data(struct rtc_time *tm, u8 *data)
  60 {
  61         data[RTC_SEC] &= ~DA9063_COUNT_SEC_MASK;
  62         data[RTC_SEC] |= tm->tm_sec & DA9063_COUNT_SEC_MASK;
  63
  64         data[RTC_MIN] &= ~DA9063_COUNT_MIN_MASK;
  65         data[RTC_MIN] |= tm->tm_min & DA9063_COUNT_MIN_MASK;
  66
  67         data[RTC_HOUR] &= ~DA9063_COUNT_HOUR_MASK;
  68         data[RTC_HOUR] |= tm->tm_hour & DA9063_COUNT_HOUR_MASK;
  69
  70         data[RTC_DAY] &= ~DA9063_COUNT_DAY_MASK;
  71         data[RTC_DAY] |= tm->tm_mday & DA9063_COUNT_DAY_MASK;
  72
  73         data[RTC_MONTH] &= ~DA9063_COUNT_MONTH_MASK;
  74         data[RTC_MONTH] |= MONTHS_TO_DA9063(tm->tm_mon) &
  75                                 DA9063_COUNT_MONTH_MASK;
  76
  77         data[RTC_YEAR] &= ~DA9063_COUNT_YEAR_MASK;
  78         data[RTC_YEAR] |= YEARS_TO_DA9063(tm->tm_year) &
  79                                 DA9063_COUNT_YEAR_MASK;
  80 }
  81
  82 static int da9063_rtc_stop_alarm(struct device *dev)
  83 {
  84         struct da9063_rtc *rtc = dev_get_drvdata(dev);
  85
  86         return regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
  87                                   DA9063_ALARM_ON, 0);
  88 }
  89
  90 static int da9063_rtc_start_alarm(struct device *dev)
  91 {
  92         struct da9063_rtc *rtc = dev_get_drvdata(dev);
  93
  94         return regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
  95                                   DA9063_ALARM_ON, DA9063_ALARM_ON);
  96 }
  97
  98 static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
  99 {
 100         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 101         unsigned long tm_secs;
 102         unsigned long al_secs;
 103         u8 data[RTC_DATA_LEN];
 104         int ret;
 105
 106         ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_COUNT_S,
 107                                data, RTC_DATA_LEN);
 108         if (ret < 0) {
 109                 dev_err(dev, "Failed to read RTC time data: %d\n", ret);
 110                 return ret;
 111         }
 112
 113         if (!(data[RTC_SEC] & DA9063_RTC_READ)) {
 114                 dev_dbg(dev, "RTC not yet ready to be read by the host\n");
 115                 return -EINVAL;
 116         }
 117
 118         da9063_data_to_tm(data, tm);
 119
 120         rtc_tm_to_time(tm, &tm_secs);
 121         rtc_tm_to_time(&rtc->alarm_time, &al_secs);
 122
 123         /* handle the rtc synchronisation delay */
 124         if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
 125                 memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
 126         else
 127                 rtc->rtc_sync = false;
 128
 129         return rtc_valid_tm(tm);
 130 }
 131
 132 static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
 133 {
 134         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 135         u8 data[RTC_DATA_LEN];
 136         int ret;
 137
 138         da9063_tm_to_data(tm, data);
 139         ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_COUNT_S,
 140                                 data, RTC_DATA_LEN);
 141         if (ret < 0)
 142                 dev_err(dev, "Failed to set RTC time data: %d\n", ret);
 143
 144         return ret;
 145 }
 146
 147 static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 148 {
 149         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 150         u8 data[RTC_DATA_LEN];
 151         int ret;
 152         unsigned int val;
 153
 154         ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_ALARM_S,
 155                                &data[RTC_SEC], RTC_DATA_LEN);
 156         if (ret < 0)
 157                 return ret;
 158
 159         da9063_data_to_tm(data, &alrm->time);
 160
 161         alrm->enabled = !!(data[RTC_YEAR] & DA9063_ALARM_ON);
 162
 163         ret = regmap_read(rtc->hw->regmap, DA9063_REG_EVENT_A, &val);
 164         if (ret < 0)
 165                 return ret;
 166
 167         if (val & (DA9063_E_ALARM))
 168                 alrm->pending = 1;
 169         else
 170                 alrm->pending = 0;
 171
 172         return 0;
 173 }
 174
 175 static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 176 {
 177         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 178         u8 data[RTC_DATA_LEN];
 179         int ret;
 180
 181         da9063_tm_to_data(&alrm->time, data);
 182
 183         ret = da9063_rtc_stop_alarm(dev);
 184         if (ret < 0) {
 185                 dev_err(dev, "Failed to stop alarm: %d\n", ret);
 186                 return ret;
 187         }
 188
 189         ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_ALARM_S,
 190                                 data, RTC_DATA_LEN);
 191         if (ret < 0) {
 192                 dev_err(dev, "Failed to write alarm: %d\n", ret);
 193                 return ret;
 194         }
 195
 196         rtc->alarm_time = alrm->time;
 197
 198         if (alrm->enabled) {
 199                 ret = da9063_rtc_start_alarm(dev);
 200                 if (ret < 0) {
 201                         dev_err(dev, "Failed to start alarm: %d\n", ret);
 202                         return ret;
 203                 }
 204         }
 205
 206         return ret;
 207 }
 208
 209 static int da9063_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 210 {
 211         if (enabled)
 212                 return da9063_rtc_start_alarm(dev);
 213         else
 214                 return da9063_rtc_stop_alarm(dev);
 215 }
 216
 217 static irqreturn_t da9063_alarm_event(int irq, void *data)
 218 {
 219         struct da9063_rtc *rtc = data;
 220
 221         regmap_update_bits(rtc->hw->regmap, DA9063_REG_ALARM_Y,
 222                            DA9063_ALARM_ON, 0);
 223
 224         rtc->rtc_sync = true;
 225         rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
 226
 227         return IRQ_HANDLED;
 228 }
 229
 230 static const struct rtc_class_ops da9063_rtc_ops = {
 231         .read_time = da9063_rtc_read_time,
 232         .set_time = da9063_rtc_set_time,
 233         .read_alarm = da9063_rtc_read_alarm,
 234         .set_alarm = da9063_rtc_set_alarm,
 235         .alarm_irq_enable = da9063_rtc_alarm_irq_enable,
 236 };
 237
 238 static int da9063_rtc_probe(struct platform_device *pdev)
 239 {
 240         struct da9063 *da9063 = dev_get_drvdata(pdev->dev.parent);
 241         struct da9063_rtc *rtc;
 242         int irq_alarm;
 243         u8 data[RTC_DATA_LEN];
 244         int ret;
 245
 246         ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_E,
 247                                  DA9063_RTC_EN, DA9063_RTC_EN);
 248         if (ret < 0) {
 249                 dev_err(&pdev->dev, "Failed to enable RTC\n");
 250                 goto err;
 251         }
 252
 253         ret = regmap_update_bits(da9063->regmap, DA9063_REG_EN_32K,
 254                                  DA9063_CRYSTAL, DA9063_CRYSTAL);
 255         if (ret < 0) {
 256                 dev_err(&pdev->dev, "Failed to run 32kHz oscillator\n");
 257                 goto err;
 258         }
 259
 260         ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_S,
 261                         DA9063_ALARM_STATUS_TICK | DA9063_ALARM_STATUS_ALARM,
 262                         0);
 263         if (ret < 0) {
 264                 dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
 265                 goto err;
 266         }
 267
 268         ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_S,
 269                                  DA9063_ALARM_STATUS_ALARM,
 270                                  DA9063_ALARM_STATUS_ALARM);
 271         if (ret < 0) {
 272                 dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
 273                 goto err;
 274         }
 275
 276         ret = regmap_update_bits(da9063->regmap, DA9063_REG_ALARM_Y,
 277                                  DA9063_TICK_ON, 0);
 278         if (ret < 0) {
 279                 dev_err(&pdev->dev, "Failed to disable TICKs\n");
 280                 goto err;
 281         }
 282
 283         ret = regmap_bulk_read(da9063->regmap, DA9063_REG_ALARM_S,
 284                                data, RTC_DATA_LEN);
 285         if (ret < 0) {
 286                 dev_err(&pdev->dev, "Failed to read initial alarm data: %d\n",
 287                         ret);
 288                 goto err;
 289         }
 290
 291         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 292         if (!rtc)
 293                 return -ENOMEM;
 294
 295         platform_set_drvdata(pdev, rtc);
 296
 297         irq_alarm = platform_get_irq_byname(pdev, "ALARM");
 298         ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
 299                                         da9063_alarm_event,
 300                                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 301                                         "ALARM", rtc);
 302         if (ret) {
 303                 dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
 304                         irq_alarm, ret);
 305                 goto err;
 306         }
 307
 308         rtc->hw = da9063;
 309         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
 310                                            &da9063_rtc_ops, THIS_MODULE);
 311         if (IS_ERR(rtc->rtc_dev))
 312                 return PTR_ERR(rtc->rtc_dev);
 313
 314         da9063_data_to_tm(data, &rtc->alarm_time);
 315         rtc->rtc_sync = false;
 316 err:
 317         return ret;
 318 }
 319
 320 static struct platform_driver da9063_rtc_driver = {
 321         .probe          = da9063_rtc_probe,
 322         .driver         = {
 323                 .name   = DA9063_DRVNAME_RTC,
 324                 .owner  = THIS_MODULE,
 325         },
 326 };
 327
 328 module_platform_driver(da9063_rtc_driver);
 329
 330 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 331 MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
 332 MODULE_LICENSE("GPL v2");
 333 MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);