drivers/rtc/rtc-max8998.c

   1 /*
   2  * RTC driver for Maxim MAX8998
   3  *
   4  * Copyright (C) 2010 Samsung Electronics Co.Ltd
   5  * Author: Minkyu Kang <mk7.kang@samsung.com>
   6  * Author: Joonyoung Shim <jy0922.shim@samsung.com>
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  *
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/i2c.h>
  17 #include <linux/slab.h>
  18 #include <linux/bcd.h>
  19 #include <linux/rtc.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/mfd/max8998.h>
  22 #include <linux/mfd/max8998-private.h>
  23
  24 #define MAX8998_RTC_SEC                 0x00
  25 #define MAX8998_RTC_MIN                 0x01
  26 #define MAX8998_RTC_HOUR                0x02
  27 #define MAX8998_RTC_WEEKDAY             0x03
  28 #define MAX8998_RTC_DATE                0x04
  29 #define MAX8998_RTC_MONTH               0x05
  30 #define MAX8998_RTC_YEAR1               0x06
  31 #define MAX8998_RTC_YEAR2               0x07
  32 #define MAX8998_ALARM0_SEC              0x08
  33 #define MAX8998_ALARM0_MIN              0x09
  34 #define MAX8998_ALARM0_HOUR             0x0a
  35 #define MAX8998_ALARM0_WEEKDAY          0x0b
  36 #define MAX8998_ALARM0_DATE             0x0c
  37 #define MAX8998_ALARM0_MONTH            0x0d
  38 #define MAX8998_ALARM0_YEAR1            0x0e
  39 #define MAX8998_ALARM0_YEAR2            0x0f
  40 #define MAX8998_ALARM1_SEC              0x10
  41 #define MAX8998_ALARM1_MIN              0x11
  42 #define MAX8998_ALARM1_HOUR             0x12
  43 #define MAX8998_ALARM1_WEEKDAY          0x13
  44 #define MAX8998_ALARM1_DATE             0x14
  45 #define MAX8998_ALARM1_MONTH            0x15
  46 #define MAX8998_ALARM1_YEAR1            0x16
  47 #define MAX8998_ALARM1_YEAR2            0x17
  48 #define MAX8998_ALARM0_CONF             0x18
  49 #define MAX8998_ALARM1_CONF             0x19
  50 #define MAX8998_RTC_STATUS              0x1a
  51 #define MAX8998_WTSR_SMPL_CNTL          0x1b
  52 #define MAX8998_TEST                    0x1f
  53
  54 #define HOUR_12                         (1 << 7)
  55 #define HOUR_PM                         (1 << 5)
  56 #define ALARM0_STATUS                   (1 << 1)
  57 #define ALARM1_STATUS                   (1 << 2)
  58
  59 enum {
  60         RTC_SEC = 0,
  61         RTC_MIN,
  62         RTC_HOUR,
  63         RTC_WEEKDAY,
  64         RTC_DATE,
  65         RTC_MONTH,
  66         RTC_YEAR1,
  67         RTC_YEAR2,
  68 };
  69
  70 struct max8998_rtc_info {
  71         struct device           *dev;
  72         struct max8998_dev      *max8998;
  73         struct i2c_client       *rtc;
  74         struct rtc_device       *rtc_dev;
  75         int irq;
  76 };
  77
  78 static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
  79 {
  80         tm->tm_sec = bcd2bin(data[RTC_SEC]);
  81         tm->tm_min = bcd2bin(data[RTC_MIN]);
  82         if (data[RTC_HOUR] & HOUR_12) {
  83                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
  84                 if (data[RTC_HOUR] & HOUR_PM)
  85                         tm->tm_hour += 12;
  86         } else
  87                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
  88
  89         tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
  90         tm->tm_mday = bcd2bin(data[RTC_DATE]);
  91         tm->tm_mon = bcd2bin(data[RTC_MONTH]);
  92         tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
  93         tm->tm_year -= 1900;
  94 }
  95
  96 static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
  97 {
  98         data[RTC_SEC] = bin2bcd(tm->tm_sec);
  99         data[RTC_MIN] = bin2bcd(tm->tm_min);
 100         data[RTC_HOUR] = bin2bcd(tm->tm_hour);
 101         data[RTC_WEEKDAY] = tm->tm_wday;
 102         data[RTC_DATE] = bin2bcd(tm->tm_mday);
 103         data[RTC_MONTH] = bin2bcd(tm->tm_mon);
 104         data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
 105         data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
 106 }
 107
 108 static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
 109 {
 110         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 111         u8 data[8];
 112         int ret;
 113
 114         ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
 115         if (ret < 0)
 116                 return ret;
 117
 118         max8998_data_to_tm(data, tm);
 119
 120         return rtc_valid_tm(tm);
 121 }
 122
 123 static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
 124 {
 125         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 126         u8 data[8];
 127
 128         max8998_tm_to_data(tm, data);
 129
 130         return max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
 131 }
 132
 133 static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 134 {
 135         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 136         u8 data[8];
 137         u8 val;
 138         int ret;
 139
 140         ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
 141         if (ret < 0)
 142                 return ret;
 143
 144         max8998_data_to_tm(data, &alrm->time);
 145
 146         ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
 147         if (ret < 0)
 148                 return ret;
 149
 150         alrm->enabled = !!val;
 151
 152         ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
 153         if (ret < 0)
 154                 return ret;
 155
 156         if (val & ALARM0_STATUS)
 157                 alrm->pending = 1;
 158         else
 159                 alrm->pending = 0;
 160
 161         return 0;
 162 }
 163
 164 static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
 165 {
 166         return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
 167 }
 168
 169 static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
 170 {
 171         return max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0x77);
 172 }
 173
 174 static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 175 {
 176         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 177         u8 data[8];
 178         int ret;
 179
 180         max8998_tm_to_data(&alrm->time, data);
 181
 182         ret = max8998_rtc_stop_alarm(info);
 183         if (ret < 0)
 184                 return ret;
 185
 186         ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
 187         if (ret < 0)
 188                 return ret;
 189
 190         if (alrm->enabled)
 191                 return max8998_rtc_start_alarm(info);
 192
 193         return 0;
 194 }
 195
 196 static int max8998_rtc_alarm_irq_enable(struct device *dev,
 197                                         unsigned int enabled)
 198 {
 199         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 200
 201         if (enabled)
 202                 return max8998_rtc_start_alarm(info);
 203         else
 204                 return max8998_rtc_stop_alarm(info);
 205 }
 206
 207 static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
 208 {
 209         struct max8998_rtc_info *info = data;
 210
 211         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
 212
 213         return IRQ_HANDLED;
 214 }
 215
 216 static const struct rtc_class_ops max8998_rtc_ops = {
 217         .read_time = max8998_rtc_read_time,
 218         .set_time = max8998_rtc_set_time,
 219         .read_alarm = max8998_rtc_read_alarm,
 220         .set_alarm = max8998_rtc_set_alarm,
 221         .alarm_irq_enable = max8998_rtc_alarm_irq_enable,
 222 };
 223
 224 static int __devinit max8998_rtc_probe(struct platform_device *pdev)
 225 {
 226         struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
 227         struct max8998_rtc_info *info;
 228         int ret;
 229
 230         info = kzalloc(sizeof(struct max8998_rtc_info), GFP_KERNEL);
 231         if (!info)
 232                 return -ENOMEM;
 233
 234         info->dev = &pdev->dev;
 235         info->max8998 = max8998;
 236         info->rtc = max8998->rtc;
 237         info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;
 238
 239         info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev,
 240                         &max8998_rtc_ops, THIS_MODULE);
 241
 242         if (IS_ERR(info->rtc_dev)) {
 243                 ret = PTR_ERR(info->rtc_dev);
 244                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 245                 goto out_rtc;
 246         }
 247
 248         platform_set_drvdata(pdev, info);
 249
 250         ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0,
 251                         "rtc-alarm0", info);
 252         if (ret < 0)
 253                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
 254                         info->irq, ret);
 255
 256         return 0;
 257
 258 out_rtc:
 259         kfree(info);
 260         return ret;
 261 }
 262
 263 static int __devexit max8998_rtc_remove(struct platform_device *pdev)
 264 {
 265         struct max8998_rtc_info *info = platform_get_drvdata(pdev);
 266
 267         if (info) {
 268                 free_irq(info->irq, info);
 269                 rtc_device_unregister(info->rtc_dev);
 270                 kfree(info);
 271         }
 272
 273         return 0;
 274 }
 275
 276 static struct platform_driver max8998_rtc_driver = {
 277         .driver         = {
 278                 .name   = "max8998-rtc",
 279                 .owner  = THIS_MODULE,
 280         },
 281         .probe          = max8998_rtc_probe,
 282         .remove         = __devexit_p(max8998_rtc_remove),
 283 };
 284
 285 static int __init max8998_rtc_init(void)
 286 {
 287         return platform_driver_register(&max8998_rtc_driver);
 288 }
 289 module_init(max8998_rtc_init);
 290
 291 static void __exit max8998_rtc_exit(void)
 292 {
 293         platform_driver_unregister(&max8998_rtc_driver);
 294 }
 295 module_exit(max8998_rtc_exit);
 296
 297 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 298 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
 299 MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
 300 MODULE_LICENSE("GPL");