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/rtc.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/mfd/max8925.h>
  17
  18 enum {
  19         RTC_SEC = 0,
  20         RTC_MIN,
  21         RTC_HOUR,
  22         RTC_WEEKDAY,
  23         RTC_DATE,
  24         RTC_MONTH,
  25         RTC_YEAR1,
  26         RTC_YEAR2,
  27 };
  28
  29 #define MAX8925_RTC_SEC                 0x00
  30 #define MAX8925_RTC_MIN                 0x01
  31 #define MAX8925_RTC_HOUR                0x02
  32 #define MAX8925_RTC_WEEKDAY             0x03
  33 #define MAX8925_RTC_DATE                0x04
  34 #define MAX8925_RTC_MONTH               0x05
  35 #define MAX8925_RTC_YEAR1               0x06
  36 #define MAX8925_RTC_YEAR2               0x07
  37 #define MAX8925_ALARM0_SEC              0x08
  38 #define MAX8925_ALARM0_MIN              0x09
  39 #define MAX8925_ALARM0_HOUR             0x0a
  40 #define MAX8925_ALARM0_WEEKDAY          0x0b
  41 #define MAX8925_ALARM0_DATE             0x0c
  42 #define MAX8925_ALARM0_MON              0x0d
  43 #define MAX8925_ALARM0_YEAR1            0x0e
  44 #define MAX8925_ALARM0_YEAR2            0x0f
  45 #define MAX8925_ALARM1_SEC              0x10
  46 #define MAX8925_ALARM1_MIN              0x11
  47 #define MAX8925_ALARM1_HOUR             0x12
  48 #define MAX8925_ALARM1_WEEKDAY          0x13
  49 #define MAX8925_ALARM1_DATE             0x14
  50 #define MAX8925_ALARM1_MON              0x15
  51 #define MAX8925_ALARM1_YEAR1            0x16
  52 #define MAX8925_ALARM1_YEAR2            0x17
  53 #define MAX8925_RTC_CNTL                0x1b
  54 #define MAX8925_RTC_STATUS              0x20
  55
  56 #define TIME_NUM                        8
  57 #define ALARM_1SEC                      (1 << 7)
  58 #define HOUR_12                         (1 << 7)
  59 #define HOUR_AM_PM                      (1 << 5)
  60 #define ALARM0_IRQ                      (1 << 3)
  61 #define ALARM1_IRQ                      (1 << 2)
  62 #define ALARM0_STATUS                   (1 << 2)
  63 #define ALARM1_STATUS                   (1 << 1)
  64
  65
  66 struct max8925_rtc_info {
  67         struct rtc_device       *rtc_dev;
  68         struct max8925_chip     *chip;
  69         struct i2c_client       *rtc;
  70         struct device           *dev;
  71 };
  72
  73 static irqreturn_t rtc_update_handler(int irq, void *data)
  74 {
  75         struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
  76
  77         /* disable ALARM0 except for 1SEC alarm */
  78         max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
  79         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
  80         return IRQ_HANDLED;
  81 }
  82
  83 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
  84 {
  85         if (len < TIME_NUM)
  86                 return -EINVAL;
  87         tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
  88                         + (buf[RTC_YEAR2] & 0xf) * 100
  89                         + (buf[RTC_YEAR1] >> 4) * 10
  90                         + (buf[RTC_YEAR1] & 0xf);
  91         tm->tm_year -= 1900;
  92         tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
  93                         + (buf[RTC_MONTH] & 0x0f);
  94         tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
  95                         + (buf[RTC_DATE] & 0x0f);
  96         tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
  97         if (buf[RTC_HOUR] & HOUR_12) {
  98                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
  99                                 + (buf[RTC_HOUR] & 0x0f);
 100                 if (buf[RTC_HOUR] & HOUR_AM_PM)
 101                         tm->tm_hour += 12;
 102         } else
 103                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
 104                                 + (buf[RTC_HOUR] & 0x0f);
 105         tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
 106                         + (buf[RTC_MIN] & 0x0f);
 107         tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
 108                         + (buf[RTC_SEC] & 0x0f);
 109         return 0;
 110 }
 111
 112 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
 113 {
 114         unsigned char high, low;
 115
 116         if (len < TIME_NUM)
 117                 return -EINVAL;
 118
 119         high = (tm->tm_year + 1900) / 1000;
 120         low = (tm->tm_year + 1900) / 100;
 121         low = low - high * 10;
 122         buf[RTC_YEAR2] = (high << 4) + low;
 123         high = (tm->tm_year + 1900) / 10;
 124         low = tm->tm_year + 1900;
 125         low = low - high * 10;
 126         high = high - (high / 10) * 10;
 127         buf[RTC_YEAR1] = (high << 4) + low;
 128         high = tm->tm_mon / 10;
 129         low = tm->tm_mon;
 130         low = low - high * 10;
 131         buf[RTC_MONTH] = (high << 4) + low;
 132         high = tm->tm_mday / 10;
 133         low = tm->tm_mday;
 134         low = low - high * 10;
 135         buf[RTC_DATE] = (high << 4) + low;
 136         buf[RTC_WEEKDAY] = tm->tm_wday;
 137         high = tm->tm_hour / 10;
 138         low = tm->tm_hour;
 139         low = low - high * 10;
 140         buf[RTC_HOUR] = (high << 4) + low;
 141         high = tm->tm_min / 10;
 142         low = tm->tm_min;
 143         low = low - high * 10;
 144         buf[RTC_MIN] = (high << 4) + low;
 145         high = tm->tm_sec / 10;
 146         low = tm->tm_sec;
 147         low = low - high * 10;
 148         buf[RTC_SEC] = (high << 4) + low;
 149         return 0;
 150 }
 151
 152 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
 153 {
 154         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 155         unsigned char buf[TIME_NUM];
 156         int ret;
 157
 158         ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 159         if (ret < 0)
 160                 goto out;
 161         ret = tm_calc(tm, buf, TIME_NUM);
 162 out:
 163         return ret;
 164 }
 165
 166 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
 167 {
 168         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 169         unsigned char buf[TIME_NUM];
 170         int ret;
 171
 172         ret = data_calc(buf, tm, TIME_NUM);
 173         if (ret < 0)
 174                 goto out;
 175         ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 176 out:
 177         return ret;
 178 }
 179
 180 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 181 {
 182         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 183         unsigned char buf[TIME_NUM];
 184         int ret;
 185
 186         ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 187         if (ret < 0)
 188                 goto out;
 189         ret = tm_calc(&alrm->time, buf, TIME_NUM);
 190         if (ret < 0)
 191                 goto out;
 192         ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
 193         if (ret < 0)
 194                 goto out;
 195         if ((ret & ALARM0_IRQ) == 0)
 196                 alrm->enabled = 1;
 197         else
 198                 alrm->enabled = 0;
 199         ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
 200         if (ret < 0)
 201                 goto out;
 202         if (ret & ALARM0_STATUS)
 203                 alrm->pending = 1;
 204         else
 205                 alrm->pending = 0;
 206 out:
 207         return ret;
 208 }
 209
 210 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 211 {
 212         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 213         unsigned char buf[TIME_NUM];
 214         int ret;
 215
 216         ret = data_calc(buf, &alrm->time, TIME_NUM);
 217         if (ret < 0)
 218                 goto out;
 219         ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 220         if (ret < 0)
 221                 goto out;
 222         /* only enable alarm on year/month/day/hour/min/sec */
 223         ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
 224         if (ret < 0)
 225                 goto out;
 226 out:
 227         return ret;
 228 }
 229
 230 static const struct rtc_class_ops max8925_rtc_ops = {
 231         .read_time      = max8925_rtc_read_time,
 232         .set_time       = max8925_rtc_set_time,
 233         .read_alarm     = max8925_rtc_read_alarm,
 234         .set_alarm      = max8925_rtc_set_alarm,
 235 };
 236
 237 static int __devinit max8925_rtc_probe(struct platform_device *pdev)
 238 {
 239         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
 240         struct max8925_rtc_info *info;
 241         int irq, ret;
 242
 243         info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL);
 244         if (!info)
 245                 return -ENOMEM;
 246         info->chip = chip;
 247         info->rtc = chip->rtc;
 248         info->dev = &pdev->dev;
 249         irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0;
 250
 251         ret = request_threaded_irq(irq, NULL, rtc_update_handler,
 252                                    IRQF_ONESHOT, "rtc-alarm0", info);
 253         if (ret < 0) {
 254                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
 255                         irq, ret);
 256                 goto out_irq;
 257         }
 258
 259         info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
 260                                         &max8925_rtc_ops, THIS_MODULE);
 261         ret = PTR_ERR(info->rtc_dev);
 262         if (IS_ERR(info->rtc_dev)) {
 263                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 264                 goto out_rtc;
 265         }
 266
 267         dev_set_drvdata(&pdev->dev, info);
 268         platform_set_drvdata(pdev, info);
 269
 270         return 0;
 271 out_rtc:
 272         free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
 273 out_irq:
 274         kfree(info);
 275         return ret;
 276 }
 277
 278 static int __devexit max8925_rtc_remove(struct platform_device *pdev)
 279 {
 280         struct max8925_rtc_info *info = platform_get_drvdata(pdev);
 281
 282         if (info) {
 283                 free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
 284                 rtc_device_unregister(info->rtc_dev);
 285                 kfree(info);
 286         }
 287         return 0;
 288 }
 289
 290 static struct platform_driver max8925_rtc_driver = {
 291         .driver         = {
 292                 .name   = "max8925-rtc",
 293                 .owner  = THIS_MODULE,
 294         },
 295         .probe          = max8925_rtc_probe,
 296         .remove         = __devexit_p(max8925_rtc_remove),
 297 };
 298
 299 static int __init max8925_rtc_init(void)
 300 {
 301         return platform_driver_register(&max8925_rtc_driver);
 302 }
 303 module_init(max8925_rtc_init);
 304
 305 static void __exit max8925_rtc_exit(void)
 306 {
 307         platform_driver_unregister(&max8925_rtc_driver);
 308 }
 309 module_exit(max8925_rtc_exit);
 310
 311 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
 312 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 313 MODULE_LICENSE("GPL");
 314