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