/drivers/rtc/rtc-max8998.c
C | 345 lines | 266 code | 65 blank | 14 comment | 21 complexity | 1be3ef123ed33db1ae6a8a13662f3c65 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
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 60enum { 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 71struct 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 80static 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 98static 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 110static 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 125static 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 141static 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 172static 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 182static 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 199static 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 224static 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 235static 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 244static 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 252static int __devinit 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 295out_rtc: 296 platform_set_drvdata(pdev, NULL); 297 kfree(info); 298 return ret; 299} 300 301static int __devexit 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 314static const struct platform_device_id max8998_rtc_id[] = { 315 { "max8998-rtc", TYPE_MAX8998 }, 316 { "lp3974-rtc", TYPE_LP3974 }, 317 { } 318}; 319 320static struct platform_driver max8998_rtc_driver = { 321 .driver = { 322 .name = "max8998-rtc", 323 .owner = THIS_MODULE, 324 }, 325 .probe = max8998_rtc_probe, 326 .remove = __devexit_p(max8998_rtc_remove), 327 .id_table = max8998_rtc_id, 328}; 329 330static int __init max8998_rtc_init(void) 331{ 332 return platform_driver_register(&max8998_rtc_driver); 333} 334module_init(max8998_rtc_init); 335 336static void __exit max8998_rtc_exit(void) 337{ 338 platform_driver_unregister(&max8998_rtc_driver); 339} 340module_exit(max8998_rtc_exit); 341 342MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 343MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>"); 344MODULE_DESCRIPTION("Maxim MAX8998 RTC driver"); 345MODULE_LICENSE("GPL");