drivers/rtc/rtc-da9052.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Real time clock driver for DA9052
   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 #include <linux/err.h>
  14 #include <linux/delay.h>
  15
  16 #include <linux/mfd/da9052/da9052.h>
  17 #include <linux/mfd/da9052/reg.h>
  18
  19 #define rtc_err(rtc, fmt, ...) \
  20                 dev_err(rtc->da9052->dev, "%s: " fmt, __func__, ##__VA_ARGS__)
  21
  22 #define DA9052_GET_TIME_RETRIES 5
  23
  24 struct da9052_rtc {
  25         struct rtc_device *rtc;
  26         struct da9052 *da9052;
  27 };
  28
  29 static int da9052_rtc_enable_alarm(struct da9052_rtc *rtc, bool enable)
  30 {
  31         int ret;
  32         if (enable) {
  33                 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
  34                                 DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON,
  35                                 DA9052_ALARM_Y_ALARM_ON);
  36                 if (ret != 0)
  37                         rtc_err(rtc, "Failed to enable ALM: %d\n", ret);
  38         } else {
  39                 ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
  40                         DA9052_ALARM_Y_ALARM_ON|DA9052_ALARM_Y_TICK_ON, 0);
  41                 if (ret != 0)
  42                         rtc_err(rtc, "Write error: %d\n", ret);
  43         }
  44         return ret;
  45 }
  46
  47 static irqreturn_t da9052_rtc_irq(int irq, void *data)
  48 {
  49         struct da9052_rtc *rtc = data;
  50
  51         rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
  52
  53         return IRQ_HANDLED;
  54 }
  55
  56 static int da9052_read_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
  57 {
  58         int ret;
  59         uint8_t v[2][5];
  60         int idx = 1;
  61         int timeout = DA9052_GET_TIME_RETRIES;
  62
  63         ret = da9052_group_read(rtc->da9052, DA9052_ALARM_MI_REG, 5, &v[0][0]);
  64         if (ret) {
  65                 rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
  66                 return ret;
  67         }
  68
  69         do {
  70                 ret = da9052_group_read(rtc->da9052,
  71                                         DA9052_ALARM_MI_REG, 5, &v[idx][0]);
  72                 if (ret) {
  73                         rtc_err(rtc, "Failed to group read ALM: %d\n", ret);
  74                         return ret;
  75                 }
  76
  77                 if (memcmp(&v[0][0], &v[1][0], 5) == 0) {
  78                         rtc_tm->tm_year = (v[0][4] & DA9052_RTC_YEAR) + 100;
  79                         rtc_tm->tm_mon  = (v[0][3] & DA9052_RTC_MONTH) - 1;
  80                         rtc_tm->tm_mday = v[0][2] & DA9052_RTC_DAY;
  81                         rtc_tm->tm_hour = v[0][1] & DA9052_RTC_HOUR;
  82                         rtc_tm->tm_min  = v[0][0] & DA9052_RTC_MIN;
  83                         rtc_tm->tm_sec = 0;
  84
  85                         ret = rtc_valid_tm(rtc_tm);
  86                         return ret;
  87                 }
  88
  89                 idx = (1-idx);
  90                 msleep(20);
  91
  92         } while (timeout--);
  93
  94         rtc_err(rtc, "Timed out reading alarm time\n");
  95
  96         return -EIO;
  97 }
  98
  99 static int da9052_set_alarm(struct da9052_rtc *rtc, struct rtc_time *rtc_tm)
 100 {
 101         struct da9052 *da9052 = rtc->da9052;
 102         unsigned long alm_time;
 103         int ret;
 104         uint8_t v[3];
 105
 106         alm_time = rtc_tm_to_time64(rtc_tm);
 107
 108         if (rtc_tm->tm_sec > 0) {
 109                 alm_time += 60 - rtc_tm->tm_sec;
 110                 rtc_time64_to_tm(alm_time, rtc_tm);
 111         }
 112         BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
 113
 114         rtc_tm->tm_year -= 100;
 115         rtc_tm->tm_mon += 1;
 116
 117         ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
 118                                 DA9052_RTC_MIN, rtc_tm->tm_min);
 119         if (ret != 0) {
 120                 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
 121                 return ret;
 122         }
 123
 124         v[0] = rtc_tm->tm_hour;
 125         v[1] = rtc_tm->tm_mday;
 126         v[2] = rtc_tm->tm_mon;
 127
 128         ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
 129         if (ret < 0)
 130                 return ret;
 131
 132         ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
 133                                 DA9052_RTC_YEAR, rtc_tm->tm_year);
 134         if (ret != 0)
 135                 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
 136
 137         return ret;
 138 }
 139
 140 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
 141 {
 142         int ret;
 143
 144         ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
 145         if (ret < 0) {
 146                 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
 147                 return ret;
 148         }
 149
 150         return !!(ret&DA9052_ALARM_Y_ALARM_ON);
 151 }
 152
 153 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
 154 {
 155         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 156         int ret;
 157         uint8_t v[2][6];
 158         int idx = 1;
 159         int timeout = DA9052_GET_TIME_RETRIES;
 160
 161         ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
 162         if (ret) {
 163                 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
 164                 return ret;
 165         }
 166
 167         do {
 168                 ret = da9052_group_read(rtc->da9052,
 169                                         DA9052_COUNT_S_REG, 6, &v[idx][0]);
 170                 if (ret) {
 171                         rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
 172                         return ret;
 173                 }
 174
 175                 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
 176                         rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
 177                         rtc_tm->tm_mon  = (v[0][4] & DA9052_RTC_MONTH) - 1;
 178                         rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
 179                         rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
 180                         rtc_tm->tm_min  = v[0][1] & DA9052_RTC_MIN;
 181                         rtc_tm->tm_sec  = v[0][0] & DA9052_RTC_SEC;
 182
 183                         return 0;
 184                 }
 185
 186                 idx = (1-idx);
 187                 msleep(20);
 188
 189         } while (timeout--);
 190
 191         rtc_err(rtc, "Timed out reading time\n");
 192
 193         return -EIO;
 194 }
 195
 196 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
 197 {
 198         struct da9052_rtc *rtc;
 199         uint8_t v[6];
 200         int ret;
 201
 202         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
 203         if ((tm->tm_year < 100) || (tm->tm_year > 163))
 204                 return -EINVAL;
 205
 206         rtc = dev_get_drvdata(dev);
 207
 208         v[0] = tm->tm_sec;
 209         v[1] = tm->tm_min;
 210         v[2] = tm->tm_hour;
 211         v[3] = tm->tm_mday;
 212         v[4] = tm->tm_mon + 1;
 213         v[5] = tm->tm_year - 100;
 214
 215         ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
 216         if (ret < 0)
 217                 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
 218         return ret;
 219 }
 220
 221 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 222 {
 223         int ret;
 224         struct rtc_time *tm = &alrm->time;
 225         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 226
 227         ret = da9052_read_alarm(rtc, tm);
 228         if (ret < 0) {
 229                 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
 230                 return ret;
 231         }
 232
 233         alrm->enabled = da9052_rtc_get_alarm_status(rtc);
 234         return 0;
 235 }
 236
 237 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 238 {
 239         int ret;
 240         struct rtc_time *tm = &alrm->time;
 241         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 242
 243         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
 244         if ((tm->tm_year < 100) || (tm->tm_year > 163))
 245                 return -EINVAL;
 246
 247         ret = da9052_rtc_enable_alarm(rtc, 0);
 248         if (ret < 0)
 249                 return ret;
 250
 251         ret = da9052_set_alarm(rtc, tm);
 252         if (ret < 0)
 253                 return ret;
 254
 255         ret = da9052_rtc_enable_alarm(rtc, 1);
 256         return ret;
 257 }
 258
 259 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 260 {
 261         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 262
 263         return da9052_rtc_enable_alarm(rtc, enabled);
 264 }
 265
 266 static const struct rtc_class_ops da9052_rtc_ops = {
 267         .read_time      = da9052_rtc_read_time,
 268         .set_time       = da9052_rtc_set_time,
 269         .read_alarm     = da9052_rtc_read_alarm,
 270         .set_alarm      = da9052_rtc_set_alarm,
 271         .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
 272 };
 273
 274 static int da9052_rtc_probe(struct platform_device *pdev)
 275 {
 276         struct da9052_rtc *rtc;
 277         int ret;
 278
 279         rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
 280         if (!rtc)
 281                 return -ENOMEM;
 282
 283         rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
 284         platform_set_drvdata(pdev, rtc);
 285
 286         ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
 287         if (ret < 0) {
 288                 rtc_err(rtc,
 289                         "Failed to setup RTC battery charging: %d\n", ret);
 290                 return ret;
 291         }
 292
 293         ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
 294                                 DA9052_ALARM_Y_TICK_ON, 0);
 295         if (ret != 0)
 296                 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
 297
 298         device_init_wakeup(&pdev->dev, true);
 299         rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
 300         if (IS_ERR(rtc->rtc))
 301                 return PTR_ERR(rtc->rtc);
 302
 303         rtc->rtc->ops = &da9052_rtc_ops;
 304         rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
 305         rtc->rtc->range_max = RTC_TIMESTAMP_END_2063;
 306
 307         ret = devm_rtc_register_device(rtc->rtc);
 308         if (ret)
 309                 return ret;
 310
 311         ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
 312                                 da9052_rtc_irq, rtc);
 313         if (ret != 0) {
 314                 rtc_err(rtc, "irq registration failed: %d\n", ret);
 315                 return ret;
 316         }
 317
 318         return 0;
 319 }
 320
 321 static struct platform_driver da9052_rtc_driver = {
 322         .probe  = da9052_rtc_probe,
 323         .driver = {
 324                 .name   = "da9052-rtc",
 325         },
 326 };
 327
 328 module_platform_driver(da9052_rtc_driver);
 329
 330 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
 331 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
 332 MODULE_LICENSE("GPL");
 333 MODULE_ALIAS("platform:da9052-rtc");