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 0; 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 MODULE_DEVICE_TABLE(platform, max8998_rtc_id); 313 314 static struct platform_driver max8998_rtc_driver = { 315 .driver = { 316 .name = "max8998-rtc", 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"); 328