kernel/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_ALARM_DATA_LEN (DA9063_AD_REG_ALARM_Y - DA9063_AD_REG_ALARM_MI + 1)
  33
  34 #define RTC_DATA_LEN    (DA9063_REG_COUNT_Y - DA9063_REG_COUNT_S + 1)
  35 #define RTC_SEC         0
  36 #define RTC_MIN         1
  37 #define RTC_HOUR        2
  38 #define RTC_DAY         3
  39 #define RTC_MONTH       4
  40 #define RTC_YEAR        5
  41
  42 struct da9063_rtc {
  43         struct rtc_device       *rtc_dev;
  44         struct da9063           *hw;
  45         struct rtc_time         alarm_time;
  46         bool                    rtc_sync;
  47         int                     alarm_year;
  48         int                     alarm_start;
  49         int                     alarm_len;
  50         int                     data_start;
  51 };
  52
  53 static void da9063_data_to_tm(u8 *data, struct rtc_time *tm)
  54 {
  55         tm->tm_sec  = data[RTC_SEC]  & DA9063_COUNT_SEC_MASK;
  56         tm->tm_min  = data[RTC_MIN]  & DA9063_COUNT_MIN_MASK;
  57         tm->tm_hour = data[RTC_HOUR] & DA9063_COUNT_HOUR_MASK;
  58         tm->tm_mday = data[RTC_DAY]  & DA9063_COUNT_DAY_MASK;
  59         tm->tm_mon  = MONTHS_FROM_DA9063(data[RTC_MONTH] &
  60                                          DA9063_COUNT_MONTH_MASK);
  61         tm->tm_year = YEARS_FROM_DA9063(data[RTC_YEAR] &
  62                                         DA9063_COUNT_YEAR_MASK);
  63 }
  64
  65 static void da9063_tm_to_data(struct rtc_time *tm, u8 *data)
  66 {
  67         data[RTC_SEC] &= ~DA9063_COUNT_SEC_MASK;
  68         data[RTC_SEC] |= tm->tm_sec & DA9063_COUNT_SEC_MASK;
  69
  70         data[RTC_MIN] &= ~DA9063_COUNT_MIN_MASK;
  71         data[RTC_MIN] |= tm->tm_min & DA9063_COUNT_MIN_MASK;
  72
  73         data[RTC_HOUR] &= ~DA9063_COUNT_HOUR_MASK;
  74         data[RTC_HOUR] |= tm->tm_hour & DA9063_COUNT_HOUR_MASK;
  75
  76         data[RTC_DAY] &= ~DA9063_COUNT_DAY_MASK;
  77         data[RTC_DAY] |= tm->tm_mday & DA9063_COUNT_DAY_MASK;
  78
  79         data[RTC_MONTH] &= ~DA9063_COUNT_MONTH_MASK;
  80         data[RTC_MONTH] |= MONTHS_TO_DA9063(tm->tm_mon) &
  81                                 DA9063_COUNT_MONTH_MASK;
  82
  83         data[RTC_YEAR] &= ~DA9063_COUNT_YEAR_MASK;
  84         data[RTC_YEAR] |= YEARS_TO_DA9063(tm->tm_year) &
  85                                 DA9063_COUNT_YEAR_MASK;
  86 }
  87
  88 static int da9063_rtc_stop_alarm(struct device *dev)
  89 {
  90         struct da9063_rtc *rtc = dev_get_drvdata(dev);
  91
  92         return regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
  93                                   DA9063_ALARM_ON, 0);
  94 }
  95
  96 static int da9063_rtc_start_alarm(struct device *dev)
  97 {
  98         struct da9063_rtc *rtc = dev_get_drvdata(dev);
  99
 100         return regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
 101                                   DA9063_ALARM_ON, DA9063_ALARM_ON);
 102 }
 103
 104 static int da9063_rtc_read_time(struct device *dev, struct rtc_time *tm)
 105 {
 106         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 107         unsigned long tm_secs;
 108         unsigned long al_secs;
 109         u8 data[RTC_DATA_LEN];
 110         int ret;
 111
 112         ret = regmap_bulk_read(rtc->hw->regmap, DA9063_REG_COUNT_S,
 113                                data, RTC_DATA_LEN);
 114         if (ret < 0) {
 115                 dev_err(dev, "Failed to read RTC time data: %d\n", ret);
 116                 return ret;
 117         }
 118
 119         if (!(data[RTC_SEC] & DA9063_RTC_READ)) {
 120                 dev_dbg(dev, "RTC not yet ready to be read by the host\n");
 121                 return -EINVAL;
 122         }
 123
 124         da9063_data_to_tm(data, tm);
 125
 126         rtc_tm_to_time(tm, &tm_secs);
 127         rtc_tm_to_time(&rtc->alarm_time, &al_secs);
 128
 129         /* handle the rtc synchronisation delay */
 130         if (rtc->rtc_sync == true && al_secs - tm_secs == 1)
 131                 memcpy(tm, &rtc->alarm_time, sizeof(struct rtc_time));
 132         else
 133                 rtc->rtc_sync = false;
 134
 135         return rtc_valid_tm(tm);
 136 }
 137
 138 static int da9063_rtc_set_time(struct device *dev, struct rtc_time *tm)
 139 {
 140         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 141         u8 data[RTC_DATA_LEN];
 142         int ret;
 143
 144         da9063_tm_to_data(tm, data);
 145         ret = regmap_bulk_write(rtc->hw->regmap, DA9063_REG_COUNT_S,
 146                                 data, RTC_DATA_LEN);
 147         if (ret < 0)
 148                 dev_err(dev, "Failed to set RTC time data: %d\n", ret);
 149
 150         return ret;
 151 }
 152
 153 static int da9063_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 154 {
 155         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 156         u8 data[RTC_DATA_LEN];
 157         int ret;
 158         unsigned int val;
 159
 160         data[RTC_SEC] = 0;
 161         ret = regmap_bulk_read(rtc->hw->regmap, rtc->alarm_start,
 162                                &data[rtc->data_start], rtc->alarm_len);
 163         if (ret < 0)
 164                 return ret;
 165
 166         da9063_data_to_tm(data, &alrm->time);
 167
 168         alrm->enabled = !!(data[RTC_YEAR] & DA9063_ALARM_ON);
 169
 170         ret = regmap_read(rtc->hw->regmap, DA9063_REG_EVENT_A, &val);
 171         if (ret < 0)
 172                 return ret;
 173
 174         if (val & (DA9063_E_ALARM))
 175                 alrm->pending = 1;
 176         else
 177                 alrm->pending = 0;
 178
 179         return 0;
 180 }
 181
 182 static int da9063_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 183 {
 184         struct da9063_rtc *rtc = dev_get_drvdata(dev);
 185         u8 data[RTC_DATA_LEN];
 186         int ret;
 187
 188         da9063_tm_to_data(&alrm->time, data);
 189
 190         ret = da9063_rtc_stop_alarm(dev);
 191         if (ret < 0) {
 192                 dev_err(dev, "Failed to stop alarm: %d\n", ret);
 193                 return ret;
 194         }
 195
 196         ret = regmap_bulk_write(rtc->hw->regmap, rtc->alarm_start,
 197                                &data[rtc->data_start], rtc->alarm_len);
 198         if (ret < 0) {
 199                 dev_err(dev, "Failed to write alarm: %d\n", ret);
 200                 return ret;
 201         }
 202
 203         da9063_data_to_tm(data, &rtc->alarm_time);
 204
 205         if (alrm->enabled) {
 206                 ret = da9063_rtc_start_alarm(dev);
 207                 if (ret < 0) {
 208                         dev_err(dev, "Failed to start alarm: %d\n", ret);
 209                         return ret;
 210                 }
 211         }
 212
 213         return ret;
 214 }
 215
 216 static int da9063_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 217 {
 218         if (enabled)
 219                 return da9063_rtc_start_alarm(dev);
 220         else
 221                 return da9063_rtc_stop_alarm(dev);
 222 }
 223
 224 static irqreturn_t da9063_alarm_event(int irq, void *data)
 225 {
 226         struct da9063_rtc *rtc = data;
 227
 228         regmap_update_bits(rtc->hw->regmap, rtc->alarm_year,
 229                            DA9063_ALARM_ON, 0);
 230
 231         rtc->rtc_sync = true;
 232         rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
 233
 234         return IRQ_HANDLED;
 235 }
 236
 237 static const struct rtc_class_ops da9063_rtc_ops = {
 238         .read_time = da9063_rtc_read_time,
 239         .set_time = da9063_rtc_set_time,
 240         .read_alarm = da9063_rtc_read_alarm,
 241         .set_alarm = da9063_rtc_set_alarm,
 242         .alarm_irq_enable = da9063_rtc_alarm_irq_enable,
 243 };
 244
 245 static int da9063_rtc_probe(struct platform_device *pdev)
 246 {
 247         struct da9063 *da9063 = dev_get_drvdata(pdev->dev.parent);
 248         struct da9063_rtc *rtc;
 249         int irq_alarm;
 250         u8 data[RTC_DATA_LEN];
 251         int ret;
 252
 253         ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_E,
 254                                  DA9063_RTC_EN, DA9063_RTC_EN);
 255         if (ret < 0) {
 256                 dev_err(&pdev->dev, "Failed to enable RTC\n");
 257                 goto err;
 258         }
 259
 260         ret = regmap_update_bits(da9063->regmap, DA9063_REG_EN_32K,
 261                                  DA9063_CRYSTAL, DA9063_CRYSTAL);
 262         if (ret < 0) {
 263                 dev_err(&pdev->dev, "Failed to run 32kHz oscillator\n");
 264                 goto err;
 265         }
 266
 267         rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
 268         if (!rtc)
 269                 return -ENOMEM;
 270
 271         if (da9063->variant_code == PMIC_DA9063_AD) {
 272                 rtc->alarm_year = DA9063_AD_REG_ALARM_Y;
 273                 rtc->alarm_start = DA9063_AD_REG_ALARM_MI;
 274                 rtc->alarm_len = RTC_ALARM_DATA_LEN;
 275                 rtc->data_start = RTC_MIN;
 276         } else {
 277                 rtc->alarm_year = DA9063_BB_REG_ALARM_Y;
 278                 rtc->alarm_start = DA9063_BB_REG_ALARM_S;
 279                 rtc->alarm_len = RTC_DATA_LEN;
 280                 rtc->data_start = RTC_SEC;
 281         }
 282
 283         ret = regmap_update_bits(da9063->regmap, rtc->alarm_start,
 284                         DA9063_ALARM_STATUS_TICK | DA9063_ALARM_STATUS_ALARM,
 285                         0);
 286         if (ret < 0) {
 287                 dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
 288                 goto err;
 289         }
 290
 291         ret = regmap_update_bits(da9063->regmap, rtc->alarm_start,
 292                                  DA9063_ALARM_STATUS_ALARM,
 293                                  DA9063_ALARM_STATUS_ALARM);
 294         if (ret < 0) {
 295                 dev_err(&pdev->dev, "Failed to access RTC alarm register\n");
 296                 goto err;
 297         }
 298
 299         ret = regmap_update_bits(da9063->regmap, rtc->alarm_year,
 300                                  DA9063_TICK_ON, 0);
 301         if (ret < 0) {
 302                 dev_err(&pdev->dev, "Failed to disable TICKs\n");
 303                 goto err;
 304         }
 305
 306         data[RTC_SEC] = 0;
 307         ret = regmap_bulk_read(da9063->regmap, rtc->alarm_start,
 308                                &data[rtc->data_start], rtc->alarm_len);
 309         if (ret < 0) {
 310                 dev_err(&pdev->dev, "Failed to read initial alarm data: %d\n",
 311                         ret);
 312                 goto err;
 313         }
 314
 315         platform_set_drvdata(pdev, rtc);
 316
 317         irq_alarm = platform_get_irq_byname(pdev, "ALARM");
 318         ret = devm_request_threaded_irq(&pdev->dev, irq_alarm, NULL,
 319                                         da9063_alarm_event,
 320                                         IRQF_TRIGGER_LOW | IRQF_ONESHOT,
 321                                         "ALARM", rtc);
 322         if (ret) {
 323                 dev_err(&pdev->dev, "Failed to request ALARM IRQ %d: %d\n",
 324                         irq_alarm, ret);
 325                 goto err;
 326         }
 327
 328         rtc->hw = da9063;
 329         rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, DA9063_DRVNAME_RTC,
 330                                            &da9063_rtc_ops, THIS_MODULE);
 331         if (IS_ERR(rtc->rtc_dev))
 332                 return PTR_ERR(rtc->rtc_dev);
 333
 334         da9063_data_to_tm(data, &rtc->alarm_time);
 335         rtc->rtc_sync = false;
 336 err:
 337         return ret;
 338 }
 339
 340 static struct platform_driver da9063_rtc_driver = {
 341         .probe          = da9063_rtc_probe,
 342         .driver         = {
 343                 .name   = DA9063_DRVNAME_RTC,
 344         },
 345 };
 346
 347 module_platform_driver(da9063_rtc_driver);
 348
 349 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 350 MODULE_DESCRIPTION("Real time clock device driver for Dialog DA9063");
 351 MODULE_LICENSE("GPL v2");
 352 MODULE_ALIAS("platform:" DA9063_DRVNAME_RTC);