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 };
  73
  74 static irqreturn_t rtc_update_handler(int irq, void *data)
  75 {
  76         struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
  77
  78         /* disable ALARM0 except for 1SEC alarm */
  79         max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
  80         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
  81         return IRQ_HANDLED;
  82 }
  83
  84 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
  85 {
  86         if (len < TIME_NUM)
  87                 return -EINVAL;
  88         tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
  89                         + (buf[RTC_YEAR2] & 0xf) * 100
  90                         + (buf[RTC_YEAR1] >> 4) * 10
  91                         + (buf[RTC_YEAR1] & 0xf);
  92         tm->tm_year -= 1900;
  93         tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
  94                         + (buf[RTC_MONTH] & 0x0f);
  95         tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
  96                         + (buf[RTC_DATE] & 0x0f);
  97         tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
  98         if (buf[RTC_HOUR] & HOUR_12) {
  99                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
 100                                 + (buf[RTC_HOUR] & 0x0f);
 101                 if (buf[RTC_HOUR] & HOUR_AM_PM)
 102                         tm->tm_hour += 12;
 103         } else
 104                 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
 105                                 + (buf[RTC_HOUR] & 0x0f);
 106         tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
 107                         + (buf[RTC_MIN] & 0x0f);
 108         tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
 109                         + (buf[RTC_SEC] & 0x0f);
 110         return 0;
 111 }
 112
 113 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
 114 {
 115         unsigned char high, low;
 116
 117         if (len < TIME_NUM)
 118                 return -EINVAL;
 119
 120         high = (tm->tm_year + 1900) / 1000;
 121         low = (tm->tm_year + 1900) / 100;
 122         low = low - high * 10;
 123         buf[RTC_YEAR2] = (high << 4) + low;
 124         high = (tm->tm_year + 1900) / 10;
 125         low = tm->tm_year + 1900;
 126         low = low - high * 10;
 127         high = high - (high / 10) * 10;
 128         buf[RTC_YEAR1] = (high << 4) + low;
 129         high = tm->tm_mon / 10;
 130         low = tm->tm_mon;
 131         low = low - high * 10;
 132         buf[RTC_MONTH] = (high << 4) + low;
 133         high = tm->tm_mday / 10;
 134         low = tm->tm_mday;
 135         low = low - high * 10;
 136         buf[RTC_DATE] = (high << 4) + low;
 137         buf[RTC_WEEKDAY] = tm->tm_wday;
 138         high = tm->tm_hour / 10;
 139         low = tm->tm_hour;
 140         low = low - high * 10;
 141         buf[RTC_HOUR] = (high << 4) + low;
 142         high = tm->tm_min / 10;
 143         low = tm->tm_min;
 144         low = low - high * 10;
 145         buf[RTC_MIN] = (high << 4) + low;
 146         high = tm->tm_sec / 10;
 147         low = tm->tm_sec;
 148         low = low - high * 10;
 149         buf[RTC_SEC] = (high << 4) + low;
 150         return 0;
 151 }
 152
 153 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
 154 {
 155         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 156         unsigned char buf[TIME_NUM];
 157         int ret;
 158
 159         ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 160         if (ret < 0)
 161                 goto out;
 162         ret = tm_calc(tm, buf, TIME_NUM);
 163 out:
 164         return ret;
 165 }
 166
 167 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
 168 {
 169         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 170         unsigned char buf[TIME_NUM];
 171         int ret;
 172
 173         ret = data_calc(buf, tm, TIME_NUM);
 174         if (ret < 0)
 175                 goto out;
 176         ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
 177 out:
 178         return ret;
 179 }
 180
 181 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 182 {
 183         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 184         unsigned char buf[TIME_NUM];
 185         int ret;
 186
 187         ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 188         if (ret < 0)
 189                 goto out;
 190         ret = tm_calc(&alrm->time, buf, TIME_NUM);
 191         if (ret < 0)
 192                 goto out;
 193         ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
 194         if (ret < 0)
 195                 goto out;
 196         if ((ret & ALARM0_IRQ) == 0)
 197                 alrm->enabled = 1;
 198         else
 199                 alrm->enabled = 0;
 200         ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
 201         if (ret < 0)
 202                 goto out;
 203         if (ret & ALARM0_STATUS)
 204                 alrm->pending = 1;
 205         else
 206                 alrm->pending = 0;
 207 out:
 208         return ret;
 209 }
 210
 211 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 212 {
 213         struct max8925_rtc_info *info = dev_get_drvdata(dev);
 214         unsigned char buf[TIME_NUM];
 215         int ret;
 216
 217         ret = data_calc(buf, &alrm->time, TIME_NUM);
 218         if (ret < 0)
 219                 goto out;
 220         ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
 221         if (ret < 0)
 222                 goto out;
 223         /* only enable alarm on year/month/day/hour/min/sec */
 224         ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
 225         if (ret < 0)
 226                 goto out;
 227 out:
 228         return ret;
 229 }
 230
 231 static const struct rtc_class_ops max8925_rtc_ops = {
 232         .read_time      = max8925_rtc_read_time,
 233         .set_time       = max8925_rtc_set_time,
 234         .read_alarm     = max8925_rtc_read_alarm,
 235         .set_alarm      = max8925_rtc_set_alarm,
 236 };
 237
 238 static int __devinit max8925_rtc_probe(struct platform_device *pdev)
 239 {
 240         struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
 241         struct max8925_rtc_info *info;
 242         int irq, ret;
 243
 244         info = kzalloc(sizeof(struct max8925_rtc_info), GFP_KERNEL);
 245         if (!info)
 246                 return -ENOMEM;
 247         info->chip = chip;
 248         info->rtc = chip->rtc;
 249         info->dev = &pdev->dev;
 250         irq = chip->irq_base + MAX8925_IRQ_RTC_ALARM0;
 251
 252         ret = request_threaded_irq(irq, NULL, rtc_update_handler,
 253                                    IRQF_ONESHOT, "rtc-alarm0", info);
 254         if (ret < 0) {
 255                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
 256                         irq, ret);
 257                 goto out_irq;
 258         }
 259
 260         dev_set_drvdata(&pdev->dev, info);
 261         /* XXX - isn't this redundant? */
 262         platform_set_drvdata(pdev, info);
 263
 264         info->rtc_dev = rtc_device_register("max8925-rtc", &pdev->dev,
 265                                         &max8925_rtc_ops, THIS_MODULE);
 266         ret = PTR_ERR(info->rtc_dev);
 267         if (IS_ERR(info->rtc_dev)) {
 268                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 269                 goto out_rtc;
 270         }
 271
 272         return 0;
 273 out_rtc:
 274         platform_set_drvdata(pdev, NULL);
 275         free_irq(chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
 276 out_irq:
 277         kfree(info);
 278         return ret;
 279 }
 280
 281 static int __devexit max8925_rtc_remove(struct platform_device *pdev)
 282 {
 283         struct max8925_rtc_info *info = platform_get_drvdata(pdev);
 284
 285         if (info) {
 286                 free_irq(info->chip->irq_base + MAX8925_IRQ_RTC_ALARM0, info);
 287                 rtc_device_unregister(info->rtc_dev);
 288                 kfree(info);
 289         }
 290         return 0;
 291 }
 292
 293 static struct platform_driver max8925_rtc_driver = {
 294         .driver         = {
 295                 .name   = "max8925-rtc",
 296                 .owner  = THIS_MODULE,
 297         },
 298         .probe          = max8925_rtc_probe,
 299         .remove         = __devexit_p(max8925_rtc_remove),
 300 };
 301
 302 static int __init max8925_rtc_init(void)
 303 {
 304         return platform_driver_register(&max8925_rtc_driver);
 305 }
 306 module_init(max8925_rtc_init);
 307
 308 static void __exit max8925_rtc_exit(void)
 309 {
 310         platform_driver_unregister(&max8925_rtc_driver);
 311 }
 312 module_exit(max8925_rtc_exit);
 313
 314 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
 315 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 316 MODULE_LICENSE("GPL");
 317