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         ret = rtc_tm_to_time(rtc_tm, &alm_time);
 107         if (ret != 0)
 108                 return ret;
 109
 110         if (rtc_tm->tm_sec > 0) {
 111                 alm_time += 60 - rtc_tm->tm_sec;
 112                 rtc_time_to_tm(alm_time, rtc_tm);
 113         }
 114         BUG_ON(rtc_tm->tm_sec); /* it will cause repeated irqs if not zero */
 115
 116         rtc_tm->tm_year -= 100;
 117         rtc_tm->tm_mon += 1;
 118
 119         ret = da9052_reg_update(da9052, DA9052_ALARM_MI_REG,
 120                                 DA9052_RTC_MIN, rtc_tm->tm_min);
 121         if (ret != 0) {
 122                 rtc_err(rtc, "Failed to write ALRM MIN: %d\n", ret);
 123                 return ret;
 124         }
 125
 126         v[0] = rtc_tm->tm_hour;
 127         v[1] = rtc_tm->tm_mday;
 128         v[2] = rtc_tm->tm_mon;
 129
 130         ret = da9052_group_write(da9052, DA9052_ALARM_H_REG, 3, v);
 131         if (ret < 0)
 132                 return ret;
 133
 134         ret = da9052_reg_update(da9052, DA9052_ALARM_Y_REG,
 135                                 DA9052_RTC_YEAR, rtc_tm->tm_year);
 136         if (ret != 0)
 137                 rtc_err(rtc, "Failed to write ALRM YEAR: %d\n", ret);
 138
 139         return ret;
 140 }
 141
 142 static int da9052_rtc_get_alarm_status(struct da9052_rtc *rtc)
 143 {
 144         int ret;
 145
 146         ret = da9052_reg_read(rtc->da9052, DA9052_ALARM_Y_REG);
 147         if (ret < 0) {
 148                 rtc_err(rtc, "Failed to read ALM: %d\n", ret);
 149                 return ret;
 150         }
 151
 152         return !!(ret&DA9052_ALARM_Y_ALARM_ON);
 153 }
 154
 155 static int da9052_rtc_read_time(struct device *dev, struct rtc_time *rtc_tm)
 156 {
 157         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 158         int ret;
 159         uint8_t v[2][6];
 160         int idx = 1;
 161         int timeout = DA9052_GET_TIME_RETRIES;
 162
 163         ret = da9052_group_read(rtc->da9052, DA9052_COUNT_S_REG, 6, &v[0][0]);
 164         if (ret) {
 165                 rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
 166                 return ret;
 167         }
 168
 169         do {
 170                 ret = da9052_group_read(rtc->da9052,
 171                                         DA9052_COUNT_S_REG, 6, &v[idx][0]);
 172                 if (ret) {
 173                         rtc_err(rtc, "Failed to read RTC time : %d\n", ret);
 174                         return ret;
 175                 }
 176
 177                 if (memcmp(&v[0][0], &v[1][0], 6) == 0) {
 178                         rtc_tm->tm_year = (v[0][5] & DA9052_RTC_YEAR) + 100;
 179                         rtc_tm->tm_mon  = (v[0][4] & DA9052_RTC_MONTH) - 1;
 180                         rtc_tm->tm_mday = v[0][3] & DA9052_RTC_DAY;
 181                         rtc_tm->tm_hour = v[0][2] & DA9052_RTC_HOUR;
 182                         rtc_tm->tm_min  = v[0][1] & DA9052_RTC_MIN;
 183                         rtc_tm->tm_sec  = v[0][0] & DA9052_RTC_SEC;
 184
 185                         return 0;
 186                 }
 187
 188                 idx = (1-idx);
 189                 msleep(20);
 190
 191         } while (timeout--);
 192
 193         rtc_err(rtc, "Timed out reading time\n");
 194
 195         return -EIO;
 196 }
 197
 198 static int da9052_rtc_set_time(struct device *dev, struct rtc_time *tm)
 199 {
 200         struct da9052_rtc *rtc;
 201         uint8_t v[6];
 202         int ret;
 203
 204         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
 205         if ((tm->tm_year < 100) || (tm->tm_year > 163))
 206                 return -EINVAL;
 207
 208         rtc = dev_get_drvdata(dev);
 209
 210         v[0] = tm->tm_sec;
 211         v[1] = tm->tm_min;
 212         v[2] = tm->tm_hour;
 213         v[3] = tm->tm_mday;
 214         v[4] = tm->tm_mon + 1;
 215         v[5] = tm->tm_year - 100;
 216
 217         ret = da9052_group_write(rtc->da9052, DA9052_COUNT_S_REG, 6, v);
 218         if (ret < 0)
 219                 rtc_err(rtc, "failed to set RTC time: %d\n", ret);
 220         return ret;
 221 }
 222
 223 static int da9052_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 224 {
 225         int ret;
 226         struct rtc_time *tm = &alrm->time;
 227         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 228
 229         ret = da9052_read_alarm(rtc, tm);
 230         if (ret < 0) {
 231                 rtc_err(rtc, "failed to read RTC alarm: %d\n", ret);
 232                 return ret;
 233         }
 234
 235         alrm->enabled = da9052_rtc_get_alarm_status(rtc);
 236         return 0;
 237 }
 238
 239 static int da9052_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 240 {
 241         int ret;
 242         struct rtc_time *tm = &alrm->time;
 243         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 244
 245         /* DA9052 only has 6 bits for year - to represent 2000-2063 */
 246         if ((tm->tm_year < 100) || (tm->tm_year > 163))
 247                 return -EINVAL;
 248
 249         ret = da9052_rtc_enable_alarm(rtc, 0);
 250         if (ret < 0)
 251                 return ret;
 252
 253         ret = da9052_set_alarm(rtc, tm);
 254         if (ret < 0)
 255                 return ret;
 256
 257         ret = da9052_rtc_enable_alarm(rtc, 1);
 258         return ret;
 259 }
 260
 261 static int da9052_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 262 {
 263         struct da9052_rtc *rtc = dev_get_drvdata(dev);
 264
 265         return da9052_rtc_enable_alarm(rtc, enabled);
 266 }
 267
 268 static const struct rtc_class_ops da9052_rtc_ops = {
 269         .read_time      = da9052_rtc_read_time,
 270         .set_time       = da9052_rtc_set_time,
 271         .read_alarm     = da9052_rtc_read_alarm,
 272         .set_alarm      = da9052_rtc_set_alarm,
 273         .alarm_irq_enable = da9052_rtc_alarm_irq_enable,
 274 };
 275
 276 static int da9052_rtc_probe(struct platform_device *pdev)
 277 {
 278         struct da9052_rtc *rtc;
 279         int ret;
 280
 281         rtc = devm_kzalloc(&pdev->dev, sizeof(struct da9052_rtc), GFP_KERNEL);
 282         if (!rtc)
 283                 return -ENOMEM;
 284
 285         rtc->da9052 = dev_get_drvdata(pdev->dev.parent);
 286         platform_set_drvdata(pdev, rtc);
 287
 288         ret = da9052_reg_write(rtc->da9052, DA9052_BBAT_CONT_REG, 0xFE);
 289         if (ret < 0) {
 290                 rtc_err(rtc,
 291                         "Failed to setup RTC battery charging: %d\n", ret);
 292                 return ret;
 293         }
 294
 295         ret = da9052_reg_update(rtc->da9052, DA9052_ALARM_Y_REG,
 296                                 DA9052_ALARM_Y_TICK_ON, 0);
 297         if (ret != 0)
 298                 rtc_err(rtc, "Failed to disable TICKS: %d\n", ret);
 299
 300         device_init_wakeup(&pdev->dev, true);
 301         rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
 302                                        &da9052_rtc_ops, THIS_MODULE);
 303
 304         if (IS_ERR(rtc->rtc))
 305                 return PTR_ERR(rtc->rtc);
 306
 307         ret = da9052_request_irq(rtc->da9052, DA9052_IRQ_ALARM, "ALM",
 308                                 da9052_rtc_irq, rtc);
 309         if (ret != 0) {
 310                 rtc_err(rtc, "irq registration failed: %d\n", ret);
 311                 return ret;
 312         }
 313
 314         return 0;
 315 }
 316
 317 static struct platform_driver da9052_rtc_driver = {
 318         .probe  = da9052_rtc_probe,
 319         .driver = {
 320                 .name   = "da9052-rtc",
 321         },
 322 };
 323
 324 module_platform_driver(da9052_rtc_driver);
 325
 326 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
 327 MODULE_DESCRIPTION("RTC driver for Dialog DA9052 PMIC");
 328 MODULE_LICENSE("GPL");
 329 MODULE_ALIAS("platform:da9052-rtc");