1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // RTC driver for Maxim MAX8998 4 // 5 // Copyright (C) 2010 Samsung Electronics Co.Ltd 6 // Author: Minkyu Kang <mk7.kang@samsung.com> 7 // Author: Joonyoung Shim <jy0922.shim@samsung.com> 8 9 #include <linux/module.h> 10 #include <linux/i2c.h> 11 #include <linux/slab.h> 12 #include <linux/bcd.h> 13 #include <linux/irqdomain.h> 14 #include <linux/rtc.h> 15 #include <linux/platform_device.h> 16 #include <linux/mfd/max8998.h> 17 #include <linux/mfd/max8998-private.h> 18 #include <linux/delay.h> 19 20 #define MAX8998_RTC_SEC 0x00 21 #define MAX8998_RTC_MIN 0x01 22 #define MAX8998_RTC_HOUR 0x02 23 #define MAX8998_RTC_WEEKDAY 0x03 24 #define MAX8998_RTC_DATE 0x04 25 #define MAX8998_RTC_MONTH 0x05 26 #define MAX8998_RTC_YEAR1 0x06 27 #define MAX8998_RTC_YEAR2 0x07 28 #define MAX8998_ALARM0_SEC 0x08 29 #define MAX8998_ALARM0_MIN 0x09 30 #define MAX8998_ALARM0_HOUR 0x0a 31 #define MAX8998_ALARM0_WEEKDAY 0x0b 32 #define MAX8998_ALARM0_DATE 0x0c 33 #define MAX8998_ALARM0_MONTH 0x0d 34 #define MAX8998_ALARM0_YEAR1 0x0e 35 #define MAX8998_ALARM0_YEAR2 0x0f 36 #define MAX8998_ALARM1_SEC 0x10 37 #define MAX8998_ALARM1_MIN 0x11 38 #define MAX8998_ALARM1_HOUR 0x12 39 #define MAX8998_ALARM1_WEEKDAY 0x13 40 #define MAX8998_ALARM1_DATE 0x14 41 #define MAX8998_ALARM1_MONTH 0x15 42 #define MAX8998_ALARM1_YEAR1 0x16 43 #define MAX8998_ALARM1_YEAR2 0x17 44 #define MAX8998_ALARM0_CONF 0x18 45 #define MAX8998_ALARM1_CONF 0x19 46 #define MAX8998_RTC_STATUS 0x1a 47 #define MAX8998_WTSR_SMPL_CNTL 0x1b 48 #define MAX8998_TEST 0x1f 49 50 #define HOUR_12 (1 << 7) 51 #define HOUR_PM (1 << 5) 52 #define ALARM0_STATUS (1 << 1) 53 #define ALARM1_STATUS (1 << 2) 54 55 enum { 56 RTC_SEC = 0, 57 RTC_MIN, 58 RTC_HOUR, 59 RTC_WEEKDAY, 60 RTC_DATE, 61 RTC_MONTH, 62 RTC_YEAR1, 63 RTC_YEAR2, 64 }; 65 66 struct max8998_rtc_info { 67 struct device *dev; 68 struct max8998_dev *max8998; 69 struct i2c_client *rtc; 70 struct rtc_device *rtc_dev; 71 int irq; 72 bool lp3974_bug_workaround; 73 }; 74 75 static void max8998_data_to_tm(u8 *data, struct rtc_time *tm) 76 { 77 tm->tm_sec = bcd2bin(data[RTC_SEC]); 78 tm->tm_min = bcd2bin(data[RTC_MIN]); 79 if (data[RTC_HOUR] & HOUR_12) { 80 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f); 81 if (data[RTC_HOUR] & HOUR_PM) 82 tm->tm_hour += 12; 83 } else 84 tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); 85 86 tm->tm_wday = data[RTC_WEEKDAY] & 0x07; 87 tm->tm_mday = bcd2bin(data[RTC_DATE]); 88 tm->tm_mon = bcd2bin(data[RTC_MONTH]); 89 tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100; 90 tm->tm_year -= 1900; 91 } 92 93 static void max8998_tm_to_data(struct rtc_time *tm, u8 *data) 94 { 95 data[RTC_SEC] = bin2bcd(tm->tm_sec); 96 data[RTC_MIN] = bin2bcd(tm->tm_min); 97 data[RTC_HOUR] = bin2bcd(tm->tm_hour); 98 data[RTC_WEEKDAY] = tm->tm_wday; 99 data[RTC_DATE] = bin2bcd(tm->tm_mday); 100 data[RTC_MONTH] = bin2bcd(tm->tm_mon); 101 data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100); 102 data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100); 103 } 104 105 static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm) 106 { 107 struct max8998_rtc_info *info = dev_get_drvdata(dev); 108 u8 data[8]; 109 int ret; 110 111 ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data); 112 if (ret < 0) 113 return ret; 114 115 max8998_data_to_tm(data, tm); 116 117 return 0; 118 } 119 120 static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm) 121 { 122 struct max8998_rtc_info *info = dev_get_drvdata(dev); 123 u8 data[8]; 124 int ret; 125 126 max8998_tm_to_data(tm, data); 127 128 ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data); 129 130 if (info->lp3974_bug_workaround) 131 msleep(2000); 132 133 return ret; 134 } 135 136 static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 137 { 138 struct max8998_rtc_info *info = dev_get_drvdata(dev); 139 u8 data[8]; 140 u8 val; 141 int ret; 142 143 ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data); 144 if (ret < 0) 145 return ret; 146 147 max8998_data_to_tm(data, &alrm->time); 148 149 ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val); 150 if (ret < 0) 151 return ret; 152 153 alrm->enabled = !!val; 154 155 ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val); 156 if (ret < 0) 157 return ret; 158 159 if (val & ALARM0_STATUS) 160 alrm->pending = 1; 161 else 162 alrm->pending = 0; 163 164 return 0; 165 } 166 167 static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info) 168 { 169 int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0); 170 171 if (info->lp3974_bug_workaround) 172 msleep(2000); 173 174 return ret; 175 } 176 177 static int max8998_rtc_start_alarm(struct max8998_rtc_info *info) 178 { 179 int ret; 180 u8 alarm0_conf = 0x77; 181 182 /* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */ 183 if (info->lp3974_bug_workaround) 184 alarm0_conf = 0x57; 185 186 ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf); 187 188 if (info->lp3974_bug_workaround) 189 msleep(2000); 190 191 return ret; 192 } 193 194 static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 195 { 196 struct max8998_rtc_info *info = dev_get_drvdata(dev); 197 u8 data[8]; 198 int ret; 199 200 max8998_tm_to_data(&alrm->time, data); 201 202 ret = max8998_rtc_stop_alarm(info); 203 if (ret < 0) 204 return ret; 205 206 ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data); 207 if (ret < 0) 208 return ret; 209 210 if (info->lp3974_bug_workaround) 211 msleep(2000); 212 213 if (alrm->enabled) 214 ret = max8998_rtc_start_alarm(info); 215 216 return ret; 217 } 218 219 static int max8998_rtc_alarm_irq_enable(struct device *dev, 220 unsigned int enabled) 221 { 222 struct max8998_rtc_info *info = dev_get_drvdata(dev); 223 224 if (enabled) 225 return max8998_rtc_start_alarm(info); 226 else 227 return max8998_rtc_stop_alarm(info); 228 } 229 230 static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data) 231 { 232 struct max8998_rtc_info *info = data; 233 234 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 235 236 return IRQ_HANDLED; 237 } 238 239 static const struct rtc_class_ops max8998_rtc_ops = { 240 .read_time = max8998_rtc_read_time, 241 .set_time = max8998_rtc_set_time, 242 .read_alarm = max8998_rtc_read_alarm, 243 .set_alarm = max8998_rtc_set_alarm, 244 .alarm_irq_enable = max8998_rtc_alarm_irq_enable, 245 }; 246 247 static int max8998_rtc_probe(struct platform_device *pdev) 248 { 249 struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent); 250 struct max8998_platform_data *pdata = max8998->pdata; 251 struct max8998_rtc_info *info; 252 int ret; 253 254 info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info), 255 GFP_KERNEL); 256 if (!info) 257 return -ENOMEM; 258 259 info->dev = &pdev->dev; 260 info->max8998 = max8998; 261 info->rtc = max8998->rtc; 262 263 platform_set_drvdata(pdev, info); 264 265 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc", 266 &max8998_rtc_ops, THIS_MODULE); 267 268 if (IS_ERR(info->rtc_dev)) { 269 ret = PTR_ERR(info->rtc_dev); 270 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 271 return ret; 272 } 273 274 if (!max8998->irq_domain) 275 goto no_irq; 276 277 info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0); 278 if (!info->irq) { 279 dev_warn(&pdev->dev, "Failed to map alarm IRQ\n"); 280 goto no_irq; 281 } 282 283 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 284 max8998_rtc_alarm_irq, 0, "rtc-alarm0", info); 285 286 if (ret < 0) 287 dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n", 288 info->irq, ret); 289 290 no_irq: 291 dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name); 292 if (pdata && pdata->rtc_delay) { 293 info->lp3974_bug_workaround = true; 294 dev_warn(&pdev->dev, "LP3974 with RTC REGERR option." 295 " RTC updates will be extremely slow.\n"); 296 } 297 298 return 0; 299 } 300 301 static const struct platform_device_id max8998_rtc_id[] = { 302 { "max8998-rtc", TYPE_MAX8998 }, 303 { "lp3974-rtc", TYPE_LP3974 }, 304 { } 305 }; 306 MODULE_DEVICE_TABLE(platform, max8998_rtc_id); 307 308 static struct platform_driver max8998_rtc_driver = { 309 .driver = { 310 .name = "max8998-rtc", 311 }, 312 .probe = max8998_rtc_probe, 313 .id_table = max8998_rtc_id, 314 }; 315 316 module_platform_driver(max8998_rtc_driver); 317 318 MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>"); 319 MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>"); 320 MODULE_DESCRIPTION("Maxim MAX8998 RTC driver"); 321 MODULE_LICENSE("GPL"); 322