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 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info), 260 GFP_KERNEL); 261 if (!info) 262 return -ENOMEM; 263 264 info->dev = &pdev->dev; 265 info->max8998 = max8998; 266 info->rtc = max8998->rtc; 267 info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0; 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 goto out_rtc; 278 } 279 280 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 281 max8998_rtc_alarm_irq, 0, "rtc-alarm0", info); 282 283 if (ret < 0) 284 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", 285 info->irq, ret); 286 287 dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name); 288 if (pdata && pdata->rtc_delay) { 289 info->lp3974_bug_workaround = true; 290 dev_warn(&pdev->dev, "LP3974 with RTC REGERR option." 291 " RTC updates will be extremely slow.\n"); 292 } 293 294 return 0; 295 296 out_rtc: 297 platform_set_drvdata(pdev, NULL); 298 return ret; 299 } 300 301 static int max8998_rtc_remove(struct platform_device *pdev) 302 { 303 return 0; 304 } 305 306 static const struct platform_device_id max8998_rtc_id[] = { 307 { "max8998-rtc", TYPE_MAX8998 }, 308 { "lp3974-rtc", TYPE_LP3974 }, 309 { } 310 }; 311 312 static struct platform_driver max8998_rtc_driver = { 313 .driver = { 314 .name = "max8998-rtc", 315 .owner = THIS_MODULE, 316 }, 317 .probe = max8998_rtc_probe, 318 .remove = max8998_rtc_remove, 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"); 328