kernel/drivers/rtc/rtc-da9052.c

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