1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * RTC driver for Maxim MAX8907 4 * 5 * Copyright (c) 2011-2012, NVIDIA Corporation. 6 * 7 * Based on drivers/rtc/rtc-max8925.c, 8 * Copyright (C) 2009-2010 Marvell International Ltd. 9 */ 10 11 #include <linux/bcd.h> 12 #include <linux/mfd/max8907.h> 13 #include <linux/module.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 #include <linux/rtc.h> 17 #include <linux/slab.h> 18 19 enum { 20 RTC_SEC = 0, 21 RTC_MIN, 22 RTC_HOUR, 23 RTC_WEEKDAY, 24 RTC_DATE, 25 RTC_MONTH, 26 RTC_YEAR1, 27 RTC_YEAR2, 28 }; 29 30 #define TIME_NUM 8 31 #define ALARM_1SEC (1 << 7) 32 #define HOUR_12 (1 << 7) 33 #define HOUR_AM_PM (1 << 5) 34 #define ALARM0_IRQ (1 << 3) 35 #define ALARM1_IRQ (1 << 2) 36 #define ALARM0_STATUS (1 << 2) 37 #define ALARM1_STATUS (1 << 1) 38 39 struct max8907_rtc { 40 struct max8907 *max8907; 41 struct regmap *regmap; 42 struct rtc_device *rtc_dev; 43 int irq; 44 }; 45 46 static irqreturn_t max8907_irq_handler(int irq, void *data) 47 { 48 struct max8907_rtc *rtc = data; 49 50 regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); 51 52 rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); 53 54 return IRQ_HANDLED; 55 } 56 57 static void regs_to_tm(u8 *regs, struct rtc_time *tm) 58 { 59 tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 + 60 bcd2bin(regs[RTC_YEAR1]) - 1900; 61 tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1; 62 tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f); 63 tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07); 64 if (regs[RTC_HOUR] & HOUR_12) { 65 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f); 66 if (tm->tm_hour == 12) 67 tm->tm_hour = 0; 68 if (regs[RTC_HOUR] & HOUR_AM_PM) 69 tm->tm_hour += 12; 70 } else { 71 tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f); 72 } 73 tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f); 74 tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f); 75 } 76 77 static void tm_to_regs(struct rtc_time *tm, u8 *regs) 78 { 79 u8 high, low; 80 81 high = (tm->tm_year + 1900) / 100; 82 low = tm->tm_year % 100; 83 regs[RTC_YEAR2] = bin2bcd(high); 84 regs[RTC_YEAR1] = bin2bcd(low); 85 regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); 86 regs[RTC_DATE] = bin2bcd(tm->tm_mday); 87 regs[RTC_WEEKDAY] = tm->tm_wday; 88 regs[RTC_HOUR] = bin2bcd(tm->tm_hour); 89 regs[RTC_MIN] = bin2bcd(tm->tm_min); 90 regs[RTC_SEC] = bin2bcd(tm->tm_sec); 91 } 92 93 static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm) 94 { 95 struct max8907_rtc *rtc = dev_get_drvdata(dev); 96 u8 regs[TIME_NUM]; 97 int ret; 98 99 ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs, 100 TIME_NUM); 101 if (ret < 0) 102 return ret; 103 104 regs_to_tm(regs, tm); 105 106 return 0; 107 } 108 109 static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm) 110 { 111 struct max8907_rtc *rtc = dev_get_drvdata(dev); 112 u8 regs[TIME_NUM]; 113 114 tm_to_regs(tm, regs); 115 116 return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs, 117 TIME_NUM); 118 } 119 120 static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 121 { 122 struct max8907_rtc *rtc = dev_get_drvdata(dev); 123 u8 regs[TIME_NUM]; 124 unsigned int val; 125 int ret; 126 127 ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, 128 TIME_NUM); 129 if (ret < 0) 130 return ret; 131 132 regs_to_tm(regs, &alrm->time); 133 134 ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val); 135 if (ret < 0) 136 return ret; 137 138 alrm->enabled = !!(val & 0x7f); 139 140 return 0; 141 } 142 143 static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) 144 { 145 struct max8907_rtc *rtc = dev_get_drvdata(dev); 146 u8 regs[TIME_NUM]; 147 int ret; 148 149 tm_to_regs(&alrm->time, regs); 150 151 /* Disable alarm while we update the target time */ 152 ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); 153 if (ret < 0) 154 return ret; 155 156 ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, 157 TIME_NUM); 158 if (ret < 0) 159 return ret; 160 161 if (alrm->enabled) 162 ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77); 163 164 return ret; 165 } 166 167 static const struct rtc_class_ops max8907_rtc_ops = { 168 .read_time = max8907_rtc_read_time, 169 .set_time = max8907_rtc_set_time, 170 .read_alarm = max8907_rtc_read_alarm, 171 .set_alarm = max8907_rtc_set_alarm, 172 }; 173 174 static int max8907_rtc_probe(struct platform_device *pdev) 175 { 176 struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent); 177 struct max8907_rtc *rtc; 178 int ret; 179 180 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); 181 if (!rtc) 182 return -ENOMEM; 183 platform_set_drvdata(pdev, rtc); 184 185 rtc->max8907 = max8907; 186 rtc->regmap = max8907->regmap_rtc; 187 188 rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc", 189 &max8907_rtc_ops, THIS_MODULE); 190 if (IS_ERR(rtc->rtc_dev)) { 191 ret = PTR_ERR(rtc->rtc_dev); 192 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); 193 return ret; 194 } 195 196 rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc, 197 MAX8907_IRQ_RTC_ALARM0); 198 if (rtc->irq < 0) 199 return rtc->irq; 200 201 ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, 202 max8907_irq_handler, 203 IRQF_ONESHOT, "max8907-alarm0", rtc); 204 if (ret < 0) 205 dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n", 206 rtc->irq, ret); 207 208 return ret; 209 } 210 211 static struct platform_driver max8907_rtc_driver = { 212 .driver = { 213 .name = "max8907-rtc", 214 }, 215 .probe = max8907_rtc_probe, 216 }; 217 module_platform_driver(max8907_rtc_driver); 218 219 MODULE_DESCRIPTION("Maxim MAX8907 RTC driver"); 220 MODULE_LICENSE("GPL v2"); 221