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 #include <linux/delay.h>
  24
  25 #define MAX8998_RTC_SEC                 0x00
  26 #define MAX8998_RTC_MIN                 0x01
  27 #define MAX8998_RTC_HOUR                0x02
  28 #define MAX8998_RTC_WEEKDAY             0x03
  29 #define MAX8998_RTC_DATE                0x04
  30 #define MAX8998_RTC_MONTH               0x05
  31 #define MAX8998_RTC_YEAR1               0x06
  32 #define MAX8998_RTC_YEAR2               0x07
  33 #define MAX8998_ALARM0_SEC              0x08
  34 #define MAX8998_ALARM0_MIN              0x09
  35 #define MAX8998_ALARM0_HOUR             0x0a
  36 #define MAX8998_ALARM0_WEEKDAY          0x0b
  37 #define MAX8998_ALARM0_DATE             0x0c
  38 #define MAX8998_ALARM0_MONTH            0x0d
  39 #define MAX8998_ALARM0_YEAR1            0x0e
  40 #define MAX8998_ALARM0_YEAR2            0x0f
  41 #define MAX8998_ALARM1_SEC              0x10
  42 #define MAX8998_ALARM1_MIN              0x11
  43 #define MAX8998_ALARM1_HOUR             0x12
  44 #define MAX8998_ALARM1_WEEKDAY          0x13
  45 #define MAX8998_ALARM1_DATE             0x14
  46 #define MAX8998_ALARM1_MONTH            0x15
  47 #define MAX8998_ALARM1_YEAR1            0x16
  48 #define MAX8998_ALARM1_YEAR2            0x17
  49 #define MAX8998_ALARM0_CONF             0x18
  50 #define MAX8998_ALARM1_CONF             0x19
  51 #define MAX8998_RTC_STATUS              0x1a
  52 #define MAX8998_WTSR_SMPL_CNTL          0x1b
  53 #define MAX8998_TEST                    0x1f
  54
  55 #define HOUR_12                         (1 << 7)
  56 #define HOUR_PM                         (1 << 5)
  57 #define ALARM0_STATUS                   (1 << 1)
  58 #define ALARM1_STATUS                   (1 << 2)
  59
  60 enum {
  61         RTC_SEC = 0,
  62         RTC_MIN,
  63         RTC_HOUR,
  64         RTC_WEEKDAY,
  65         RTC_DATE,
  66         RTC_MONTH,
  67         RTC_YEAR1,
  68         RTC_YEAR2,
  69 };
  70
  71 struct max8998_rtc_info {
  72         struct device           *dev;
  73         struct max8998_dev      *max8998;
  74         struct i2c_client       *rtc;
  75         struct rtc_device       *rtc_dev;
  76         int irq;
  77         bool lp3974_bug_workaround;
  78 };
  79
  80 static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
  81 {
  82         tm->tm_sec = bcd2bin(data[RTC_SEC]);
  83         tm->tm_min = bcd2bin(data[RTC_MIN]);
  84         if (data[RTC_HOUR] & HOUR_12) {
  85                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
  86                 if (data[RTC_HOUR] & HOUR_PM)
  87                         tm->tm_hour += 12;
  88         } else
  89                 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);
  90
  91         tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
  92         tm->tm_mday = bcd2bin(data[RTC_DATE]);
  93         tm->tm_mon = bcd2bin(data[RTC_MONTH]);
  94         tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
  95         tm->tm_year -= 1900;
  96 }
  97
  98 static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
  99 {
 100         data[RTC_SEC] = bin2bcd(tm->tm_sec);
 101         data[RTC_MIN] = bin2bcd(tm->tm_min);
 102         data[RTC_HOUR] = bin2bcd(tm->tm_hour);
 103         data[RTC_WEEKDAY] = tm->tm_wday;
 104         data[RTC_DATE] = bin2bcd(tm->tm_mday);
 105         data[RTC_MONTH] = bin2bcd(tm->tm_mon);
 106         data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
 107         data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
 108 }
 109
 110 static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
 111 {
 112         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 113         u8 data[8];
 114         int ret;
 115
 116         ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
 117         if (ret < 0)
 118                 return ret;
 119
 120         max8998_data_to_tm(data, tm);
 121
 122         return rtc_valid_tm(tm);
 123 }
 124
 125 static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
 126 {
 127         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 128         u8 data[8];
 129         int ret;
 130
 131         max8998_tm_to_data(tm, data);
 132
 133         ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);
 134
 135         if (info->lp3974_bug_workaround)
 136                 msleep(2000);
 137
 138         return ret;
 139 }
 140
 141 static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 142 {
 143         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 144         u8 data[8];
 145         u8 val;
 146         int ret;
 147
 148         ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
 149         if (ret < 0)
 150                 return ret;
 151
 152         max8998_data_to_tm(data, &alrm->time);
 153
 154         ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
 155         if (ret < 0)
 156                 return ret;
 157
 158         alrm->enabled = !!val;
 159
 160         ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
 161         if (ret < 0)
 162                 return ret;
 163
 164         if (val & ALARM0_STATUS)
 165                 alrm->pending = 1;
 166         else
 167                 alrm->pending = 0;
 168
 169         return 0;
 170 }
 171
 172 static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
 173 {
 174         int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);
 175
 176         if (info->lp3974_bug_workaround)
 177                 msleep(2000);
 178
 179         return ret;
 180 }
 181
 182 static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
 183 {
 184         int ret;
 185         u8 alarm0_conf = 0x77;
 186
 187         /* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */
 188         if (info->lp3974_bug_workaround)
 189                 alarm0_conf = 0x57;
 190
 191         ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf);
 192
 193         if (info->lp3974_bug_workaround)
 194                 msleep(2000);
 195
 196         return ret;
 197 }
 198
 199 static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 200 {
 201         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 202         u8 data[8];
 203         int ret;
 204
 205         max8998_tm_to_data(&alrm->time, data);
 206
 207         ret = max8998_rtc_stop_alarm(info);
 208         if (ret < 0)
 209                 return ret;
 210
 211         ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
 212         if (ret < 0)
 213                 return ret;
 214
 215         if (info->lp3974_bug_workaround)
 216                 msleep(2000);
 217
 218         if (alrm->enabled)
 219                 ret = max8998_rtc_start_alarm(info);
 220
 221         return ret;
 222 }
 223
 224 static int max8998_rtc_alarm_irq_enable(struct device *dev,
 225                                         unsigned int enabled)
 226 {
 227         struct max8998_rtc_info *info = dev_get_drvdata(dev);
 228
 229         if (enabled)
 230                 return max8998_rtc_start_alarm(info);
 231         else
 232                 return max8998_rtc_stop_alarm(info);
 233 }
 234
 235 static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
 236 {
 237         struct max8998_rtc_info *info = data;
 238
 239         rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
 240
 241         return IRQ_HANDLED;
 242 }
 243
 244 static const struct rtc_class_ops max8998_rtc_ops = {
 245         .read_time = max8998_rtc_read_time,
 246         .set_time = max8998_rtc_set_time,
 247         .read_alarm = max8998_rtc_read_alarm,
 248         .set_alarm = max8998_rtc_set_alarm,
 249         .alarm_irq_enable = max8998_rtc_alarm_irq_enable,
 250 };
 251
 252 static int max8998_rtc_probe(struct platform_device *pdev)
 253 {
 254         struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
 255         struct max8998_platform_data *pdata = dev_get_platdata(max8998->dev);
 256         struct max8998_rtc_info *info;
 257         int ret;
 258
 259         info = kzalloc(sizeof(struct max8998_rtc_info), GFP_KERNEL);
 260         if (!info)
 261                 return -ENOMEM;
 262
 263         info->dev = &pdev->dev;
 264         info->max8998 = max8998;
 265         info->rtc = max8998->rtc;
 266         info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;
 267
 268         platform_set_drvdata(pdev, info);
 269
 270         info->rtc_dev = rtc_device_register("max8998-rtc", &pdev->dev,
 271                         &max8998_rtc_ops, THIS_MODULE);
 272
 273         if (IS_ERR(info->rtc_dev)) {
 274                 ret = PTR_ERR(info->rtc_dev);
 275                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
 276                 goto out_rtc;
 277         }
 278
 279         ret = request_threaded_irq(info->irq, NULL, max8998_rtc_alarm_irq, 0,
 280                         "rtc-alarm0", info);
 281
 282         if (ret < 0)
 283                 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
 284                         info->irq, ret);
 285
 286         dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);
 287         if (pdata->rtc_delay) {
 288                 info->lp3974_bug_workaround = true;
 289                 dev_warn(&pdev->dev, "LP3974 with RTC REGERR option."
 290                                 " RTC updates will be extremely slow.\n");
 291         }
 292
 293         return 0;
 294
 295 out_rtc:
 296         platform_set_drvdata(pdev, NULL);
 297         kfree(info);
 298         return ret;
 299 }
 300
 301 static int max8998_rtc_remove(struct platform_device *pdev)
 302 {
 303         struct max8998_rtc_info *info = platform_get_drvdata(pdev);
 304
 305         if (info) {
 306                 free_irq(info->irq, info);
 307                 rtc_device_unregister(info->rtc_dev);
 308                 kfree(info);
 309         }
 310
 311         return 0;
 312 }
 313
 314 static const struct platform_device_id max8998_rtc_id[] = {
 315         { "max8998-rtc", TYPE_MAX8998 },
 316         { "lp3974-rtc", TYPE_LP3974 },
 317         { }
 318 };
 319
 320 static struct platform_driver max8998_rtc_driver = {
 321         .driver         = {
 322                 .name   = "max8998-rtc",
 323                 .owner  = THIS_MODULE,
 324         },
 325         .probe          = max8998_rtc_probe,
 326         .remove         = max8998_rtc_remove,
 327         .id_table       = max8998_rtc_id,
 328 };
 329
 330 module_platform_driver(max8998_rtc_driver);
 331
 332 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
 333 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
 334 MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
 335 MODULE_LICENSE("GPL");