1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * RTC driver for Maxim MAX8925 4 * 5 * Copyright (C) 2009-2010 Marvell International Ltd. 6 * Haojian Zhuang <haojian.zhuang@marvell.com> 7 */ 8 9 #include <linux/module.h> 10 #include <linux/i2c.h> 11 #include <linux/slab.h> 12 #include <linux/rtc.h> 13 #include <linux/platform_device.h> 14 #include <linux/mfd/max8925.h> 15 16 enum { 17 RTC_SEC = 0, 18 RTC_MIN, 19 RTC_HOUR, 20 RTC_WEEKDAY, 21 RTC_DATE, 22 RTC_MONTH, 23 RTC_YEAR1, 24 RTC_YEAR2, 25 }; 26 27 #define MAX8925_RTC_SEC 0x00 28 #define MAX8925_RTC_MIN 0x01 29 #define MAX8925_RTC_HOUR 0x02 30 #define MAX8925_RTC_WEEKDAY 0x03 31 #define MAX8925_RTC_DATE 0x04 32 #define MAX8925_RTC_MONTH 0x05 33 #define MAX8925_RTC_YEAR1 0x06 34 #define MAX8925_RTC_YEAR2 0x07 35 #define MAX8925_ALARM0_SEC 0x08 36 #define MAX8925_ALARM0_MIN 0x09 37 #define MAX8925_ALARM0_HOUR 0x0a 38 #define MAX8925_ALARM0_WEEKDAY 0x0b 39 #define MAX8925_ALARM0_DATE 0x0c 40 #define MAX8925_ALARM0_MON 0x0d 41 #define MAX8925_ALARM0_YEAR1 0x0e 42 #define MAX8925_ALARM0_YEAR2 0x0f 43 #define MAX8925_ALARM1_SEC 0x10 44 #define MAX8925_ALARM1_MIN 0x11 45 #define MAX8925_ALARM1_HOUR 0x12 46 #define MAX8925_ALARM1_WEEKDAY 0x13 47 #define MAX8925_ALARM1_DATE 0x14 48 #define MAX8925_ALARM1_MON 0x15 49 #define MAX8925_ALARM1_YEAR1 0x16 50 #define MAX8925_ALARM1_YEAR2 0x17 51 #define MAX8925_RTC_CNTL 0x1b 52 #define MAX8925_RTC_STATUS 0x20 53 54 #define TIME_NUM 8 55 #define ALARM_1SEC (1 << 7) 56 #define HOUR_12 (1 << 7) 57 #define HOUR_AM_PM (1 << 5) 58 #define ALARM0_IRQ (1 << 3) 59 #define ALARM1_IRQ (1 << 2) 60 #define ALARM0_STATUS (1 << 2) 61 #define ALARM1_STATUS (1 << 1) 62 63 64 struct max8925_rtc_info { 65 struct rtc_device *rtc_dev; 66 struct max8925_chip *chip; 67 struct i2c_client *rtc; 68 struct device *dev; 69 int irq; 70 }; 71 72 static irqreturn_t rtc_update_handler(int irq, void *data) 73 { 74 struct max8925_rtc_info *info = (struct max8925_rtc_info *)data; 75 76 /* disable ALARM0 except for 1SEC alarm */ 77 max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0); 78 rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 79 return IRQ_HANDLED; 80 } 81 82 static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len) 83 { 84 if (len < TIME_NUM) 85 return -EINVAL; 86 tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000 87 + (buf[RTC_YEAR2] & 0xf) * 100 88 + (buf[RTC_YEAR1] >> 4) * 10 89 + (buf[RTC_YEAR1] & 0xf); 90 tm->tm_year -= 1900; 91 tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10 92 + (buf[RTC_MONTH] & 0x0f); 93 tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10 94 + (buf[RTC_DATE] & 0x0f); 95 tm->tm_wday = buf[RTC_WEEKDAY] & 0x07; 96 if (buf[RTC_HOUR] & HOUR_12) { 97 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10 98 + (buf[RTC_HOUR] & 0x0f); 99 if (buf[RTC_HOUR] & HOUR_AM_PM) 100 tm->tm_hour += 12; 101 } else 102 tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10 103 + (buf[RTC_HOUR] & 0x0f); 104 tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10 105 + (buf[RTC_MIN] & 0x0f); 106 tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10 107 + (buf[RTC_SEC] & 0x0f); 108 return 0; 109 } 110 111 static int data_calc(unsigned char *buf, struct rtc_time *tm, int len) 112 { 113 unsigned char high, low; 114 115 if (len < TIME_NUM) 116 return -EINVAL; 117 118 high = (tm->tm_year + 1900) / 1000; 119 low = (tm->tm_year + 1900) / 100; 120 low = low - high * 10; 121 buf[RTC_YEAR2] = (high << 4) + low; 122 high = (tm->tm_year + 1900) / 10; 123 low = tm->tm_year + 1900; 124 low = low - high * 10; 125 high = high - (high / 10) * 10; 126 buf[RTC_YEAR1] = (high << 4) + low; 127 high = tm->tm_mon / 10; 128 low = tm->tm_mon; 129 low = low - high * 10; 130 buf[RTC_MONTH] = (high << 4) + low; 131 high = tm->tm_mday / 10; 132 low = tm->tm_mday; 133 low = low - high * 10; 134 buf[RTC_DATE] = (high << 4) + low; 135 buf[RTC_WEEKDAY] = tm->tm_wday; 136 high = tm->tm_hour / 10; 137 low = tm->tm_hour; 138 low = low - high * 10; 139 buf[RTC_HOUR] = (high << 4) + low; 140 high = tm->tm_min / 10; 141 low = tm->tm_min; 142 low = low - high * 10; 143 buf[RTC_MIN] = (high << 4) + low; 144 high = tm->tm_sec / 10; 145 low = tm->tm_sec; 146 low = low - high * 10; 147 buf[RTC_SEC] = (high << 4) + low; 148 return 0; 149 } 150 151 static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm) 152 { 153 struct max8925_rtc_info *info = dev_get_drvdata(dev); 154 unsigned char buf[TIME_NUM]; 155 int ret; 156 157 ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf); 158 if (ret < 0) 159 goto out; 160 ret = tm_calc(tm, buf, TIME_NUM); 161 out: 162 return ret; 163 } 164 165 static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm) 166 { 167 struct max8925_rtc_info *info = dev_get_drvdata(dev); 168 unsigned char buf[TIME_NUM]; 169 int ret; 170 171 ret = data_calc(buf, tm, TIME_NUM); 172 if (ret < 0) 173 goto out; 174 ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf); 175 out: 176 return ret; 177 } 178 179 static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 180 { 181 struct max8925_rtc_info *info = dev_get_drvdata(dev); 182 unsigned char buf[TIME_NUM]; 183 int ret; 184 185 ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf); 186 if (ret < 0) 187 goto out; 188 ret = tm_calc(&alrm->time, buf, TIME_NUM); 189 if (ret < 0) 190 goto out; 191 ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK); 192 if (ret < 0) 193 goto out; 194 if (ret & ALARM0_IRQ) { 195 alrm->enabled = 0; 196 } else { 197 ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL); 198 if (ret < 0) 199 goto out; 200 if (!ret) 201 alrm->enabled = 0; 202 else 203 alrm->enabled = 1; 204 } 205 ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS); 206 if (ret < 0) 207 goto out; 208 if (ret & ALARM0_STATUS) 209 alrm->pending = 1; 210 else 211 alrm->pending = 0; 212 return 0; 213 out: 214 return ret; 215 } 216 217 static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 218 { 219 struct max8925_rtc_info *info = dev_get_drvdata(dev); 220 unsigned char buf[TIME_NUM]; 221 int ret; 222 223 ret = data_calc(buf, &alrm->time, TIME_NUM); 224 if (ret < 0) 225 goto out; 226 ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf); 227 if (ret < 0) 228 goto out; 229 if (alrm->enabled) 230 /* only enable alarm on year/month/day/hour/min/sec */ 231 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77); 232 else 233 ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0); 234 out: 235 return ret; 236 } 237 238 static const struct rtc_class_ops max8925_rtc_ops = { 239 .read_time = max8925_rtc_read_time, 240 .set_time = max8925_rtc_set_time, 241 .read_alarm = max8925_rtc_read_alarm, 242 .set_alarm = max8925_rtc_set_alarm, 243 }; 244 245 static int max8925_rtc_probe(struct platform_device *pdev) 246 { 247 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); 248 struct max8925_rtc_info *info; 249 int ret; 250 251 info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info), 252 GFP_KERNEL); 253 if (!info) 254 return -ENOMEM; 255 info->chip = chip; 256 info->rtc = chip->rtc; 257 info->dev = &pdev->dev; 258 info->irq = platform_get_irq(pdev, 0); 259 260 ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL, 261 rtc_update_handler, IRQF_ONESHOT, 262 "rtc-alarm0", info); 263 if (ret < 0) { 264 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n", 265 info->irq, ret); 266 return ret; 267 } 268 269 dev_set_drvdata(&pdev->dev, info); 270 /* XXX - isn't this redundant? */ 271 platform_set_drvdata(pdev, info); 272 273 device_init_wakeup(&pdev->dev, 1); 274 275 info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc", 276 &max8925_rtc_ops, THIS_MODULE); 277 ret = PTR_ERR(info->rtc_dev); 278 if (IS_ERR(info->rtc_dev)) { 279 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 280 return ret; 281 } 282 283 return 0; 284 } 285 286 #ifdef CONFIG_PM_SLEEP 287 static int max8925_rtc_suspend(struct device *dev) 288 { 289 struct platform_device *pdev = to_platform_device(dev); 290 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); 291 292 if (device_may_wakeup(dev)) 293 chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0; 294 return 0; 295 } 296 static int max8925_rtc_resume(struct device *dev) 297 { 298 struct platform_device *pdev = to_platform_device(dev); 299 struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent); 300 301 if (device_may_wakeup(dev)) 302 chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0); 303 return 0; 304 } 305 #endif 306 307 static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume); 308 309 static struct platform_driver max8925_rtc_driver = { 310 .driver = { 311 .name = "max8925-rtc", 312 .pm = &max8925_rtc_pm_ops, 313 }, 314 .probe = max8925_rtc_probe, 315 }; 316 317 module_platform_driver(max8925_rtc_driver); 318 319 MODULE_DESCRIPTION("Maxim MAX8925 RTC driver"); 320 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>"); 321 MODULE_LICENSE("GPL"); 322 323