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