drivers/rtc/rtc-max8925.c

   1 /*
   2  * RTC driver for Maxim MAX8925
   3  *
   4  * Copyright (C) 2009-2010 Marvell International Ltd.
   5  *      Haojian Zhuang <haojian.zhuang@marvell.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/i2c.h>
  14 #include <linux/slab.h>
  15 #include <linux/rtc.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/mfd/max8925.h>
  18
  19 enum {
  20         RTC_SEC = 0,
  21         RTC_MIN,
  22         RTC_HOUR,
  23         RTC_WEEKDAY,
  24         RTC_DATE,
  25         RTC_MONTH,
  26         RTC_YEAR1,
  27         RTC_YEAR2,
  28 };
  29
  30 #define MAX8925_RTC_SEC                 0x00
  31 #define MAX8925_RTC_MIN                 0x01
  32 #define MAX8925_RTC_HOUR                0x02
  33 #define MAX8925_RTC_WEEKDAY             0x03
  34 #define MAX8925_RTC_DATE                0x04
  35 #define MAX8925_RTC_MONTH               0x05
  36 #define MAX8925_RTC_YEAR1               0x06
  37 #define MAX8925_RTC_YEAR2               0x07
  38 #define MAX8925_ALARM0_SEC              0x08
  39 #define MAX8925_ALARM0_MIN              0x09
  40 #define MAX8925_ALARM0_HOUR             0x0a
  41 #define MAX8925_ALARM0_WEEKDAY          0x0b
  42 #define MAX8925_ALARM0_DATE             0x0c
  43 #define MAX8925_ALARM0_MON              0x0d
  44 #define MAX8925_ALARM0_YEAR1            0x0e
  45 #define MAX8925_ALARM0_YEAR2            0x0f
  46 #define MAX8925_ALARM1_SEC              0x10
  47 #define MAX8925_ALARM1_MIN              0x11
  48 #define MAX8925_ALARM1_HOUR             0x12
  49 #define MAX8925_ALARM1_WEEKDAY          0x13
  50 #define MAX8925_ALARM1_DATE             0x14
  51 #define MAX8925_ALARM1_MON              0x15
  52 #define MAX8925_ALARM1_YEAR1            0x16
  53 #define MAX8925_ALARM1_YEAR2            0x17
  54 #define MAX8925_RTC_CNTL                0x1b
  55 #define MAX8925_RTC_STATUS              0x20
  56
  57 #define TIME_NUM                        8
  58 #define ALARM_1SEC                      (1 << 7)
  59 #define HOUR_12                         (1 << 7)
  60 #define HOUR_AM_PM                      (1 << 5)
  61 #define ALARM0_IRQ                      (1 << 3)
  62 #define ALARM1_IRQ                      (1 << 2)
  63 #define ALARM0_STATUS                   (1 << 2)
  64 #define ALARM1_STATUS                   (1 << 1)
  65
  66
  67 struct max8925_rtc_info {
  68         struct rtc_device       *rtc_dev;
  69         struct max8925_chip     *chip;
  70         struct i2c_client       *rtc;
  71         struct device           *dev;
  72         int                     irq;
  73 };
  74
  75 static irqreturn_t rtc_update_handler(int irq, void *data)
  76 {
  77         struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
  78
  79         /* disable ALARM0 except for 1SEC alarm */
  80         max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
  81         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
  82         return IRQ_HANDLED;
  83 }
  84
  85 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
  86 {
  87         if (len < TIME_NUM)
  88                 return -EINVAL;
  89         tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
  90                         + (buf[RTC_YEAR2] & 0xf) * 100
  91                         + (buf[RTC_YEAR1] >> 4) * 10
  92                         + (buf[RTC_YEAR1] & 0xf);
  93         tm->tm_year -= 1900;
  94         tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
  95                         + (buf[RTC_MONTH] & 0x0f);
  96         tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
  97                         + (buf[RTC_DATE] & 0x0f);
  98         tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
  99         if (buf[RTC_HOUR] & HOUR_12) {
 100                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
 101                                 + (buf[RTC_HOUR] & 0x0f);
 102                 if (buf[RTC_HOUR] & HOUR_AM_PM)
 103                         tm->tm_hour += 12;
 104         } else
 105                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
 106                                 + (buf[RTC_HOUR] & 0x0f);
 107         tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
 108                         + (buf[RTC_MIN] & 0x0f);
 109         tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
 110                         + (buf[RTC_SEC] & 0x0f);
 111         return 0;
 112 }
 113
 114 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
 115 {
 116         unsigned char high, low;
 117
 118         if (len < TIME_NUM)
 119                 return -EINVAL;
 120
 121         high = (tm->tm_year + 1900) / 1000;
 122         low = (tm->tm_year + 1900) / 100;
 123         low = low - high * 10;
 124         buf[RTC_YEAR2] = (high << 4) + low;
 125         high = (tm->tm_year + 1900) / 10;
 126         low = tm->tm_year + 1900;
 127         low = low - high * 10;
 128         high = high - (high / 10) * 10;
 129         buf[RTC_YEAR1] = (high << 4) + low;
 130         high = tm->tm_mon / 10;
 131         low = tm->tm_mon;
 132         low = low - high * 10;
 133         buf[RTC_MONTH] = (high << 4) + low;
 134         high = tm->tm_mday / 10;
 135         low = tm->tm_mday;
 136         low = low - high * 10;
 137         buf[RTC_DATE] = (high << 4) + low;
 138         buf[RTC_WEEKDAY] = tm->tm_wday;
 139         high = tm->tm_hour / 10;
 140         low = tm->tm_hour;
 141         low = low - high * 10;
 142         buf[RTC_HOUR] = (high << 4) + low;
 143         high = tm->tm_min / 10;
 144         low = tm->tm_min;
 145         low = low - high * 10;
 146         buf[RTC_MIN] = (high << 4) + low;
 147         high = tm->tm_sec / 10;
 148         low = tm->tm_sec;
 149         low = low - high * 10;
 150         buf[RTC_SEC] = (high << 4) + low;
 151         return 0;
 152 }
 153
 154 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
 155 {
 156         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 157         unsigned char buf[TIME_NUM];
 158         int ret;
 159
 160         ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 161         if (ret < 0)
 162                 goto out;
 163         ret = tm_calc(tm, buf, TIME_NUM);
 164 out:
 165         return ret;
 166 }
 167
 168 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
 169 {
 170         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 171         unsigned char buf[TIME_NUM];
 172         int ret;
 173
 174         ret = data_calc(buf, tm, TIME_NUM);
 175         if (ret < 0)
 176                 goto out;
 177         ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 178 out:
 179         return ret;
 180 }
 181
 182 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 183 {
 184         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 185         unsigned char buf[TIME_NUM];
 186         int ret;
 187
 188         ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 189         if (ret < 0)
 190                 goto out;
 191         ret = tm_calc(&alrm->time, buf, TIME_NUM);
 192         if (ret < 0)
 193                 goto out;
 194         ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
 195         if (ret < 0)
 196                 goto out;
 197         if (ret & ALARM0_IRQ) {
 198                 alrm->enabled = 0;
 199         } else {
 200                 ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
 201                 if (ret < 0)
 202                         goto out;
 203                 if (!ret)
 204                         alrm->enabled = 0;
 205                 else
 206                         alrm->enabled = 1;
 207         }
 208         ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
 209         if (ret < 0)
 210                 goto out;
 211         if (ret & ALARM0_STATUS)
 212                 alrm->pending = 1;
 213         else
 214                 alrm->pending = 0;
 215         return 0;
 216 out:
 217         return ret;
 218 }
 219
 220 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 221 {
 222         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 223         unsigned char buf[TIME_NUM];
 224         int ret;
 225
 226         ret = data_calc(buf, &alrm->time, TIME_NUM);
 227         if (ret < 0)
 228                 goto out;
 229         ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 230         if (ret < 0)
 231                 goto out;
 232         if (alrm->enabled)
 233                 /* only enable alarm on year/month/day/hour/min/sec */
 234                 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
 235         else
 236                 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
 237         if (ret < 0)
 238                 goto out;
 239 out:
 240         return ret;
 241 }
 242
 243 static const struct rtc_class_ops max8925_rtc_ops = {
 244         .read_time      = max8925_rtc_read_time,
 245         .set_time       = max8925_rtc_set_time,
 246         .read_alarm     = max8925_rtc_read_alarm,
 247         .set_alarm      = max8925_rtc_set_alarm,
 248 };
 249
 250 static int max8925_rtc_probe(struct platform_device *pdev)
 251 {
 252         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
 253         struct max8925_rtc_info *info;
 254         int ret;
 255
 256         info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
 257                             GFP_KERNEL);
 258         if (!info)
 259                 return -ENOMEM;
 260         info->chip = chip;
 261         info->rtc = chip->rtc;
 262         info->dev = &pdev->dev;
 263         info->irq = platform_get_irq(pdev, 0);
 264
 265         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
 266                                         rtc_update_handler, IRQF_ONESHOT,
 267                                         "rtc-alarm0", info);
 268         if (ret < 0) {
 269                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
 270                         info->irq, ret);
 271                 return ret;
 272         }
 273
 274         dev_set_drvdata(&pdev->dev, info);
 275         /* XXX - isn't this redundant? */
 276         platform_set_drvdata(pdev, info);
 277
 278         device_init_wakeup(&pdev->dev, 1);
 279
 280         info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
 281                                         &max8925_rtc_ops, THIS_MODULE);
 282         ret = PTR_ERR(info->rtc_dev);
 283         if (IS_ERR(info->rtc_dev)) {
 284                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 285                 return ret;
 286         }
 287
 288         return 0;
 289 }
 290
 291 #ifdef CONFIG_PM_SLEEP
 292 static int max8925_rtc_suspend(struct device *dev)
 293 {
 294         struct platform_device *pdev = to_platform_device(dev);
 295         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
 296
 297         if (device_may_wakeup(dev))
 298                 chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
 299         return 0;
 300 }
 301 static int max8925_rtc_resume(struct device *dev)
 302 {
 303         struct platform_device *pdev = to_platform_device(dev);
 304         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
 305
 306         if (device_may_wakeup(dev))
 307                 chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
 308         return 0;
 309 }
 310 #endif
 311
 312 static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
 313
 314 static struct platform_driver max8925_rtc_driver = {
 315         .driver         = {
 316                 .name   = "max8925-rtc",
 317                 .pm     = &max8925_rtc_pm_ops,
 318         },
 319         .probe          = max8925_rtc_probe,
 320 };
 321
 322 module_platform_driver(max8925_rtc_driver);
 323
 324 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
 325 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 326 MODULE_LICENSE("GPL");
 327