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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * RTC driver for Maxim MAX89074 *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 19enum {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 831#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 39struct max8907_rtc {40 struct max8907 *max8907;41 struct regmap *regmap;42 struct rtc_device *rtc_dev;43 int irq;44};45 46static 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 57static 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 77static 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 93static 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 109static 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 120static 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 143static 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 167static 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 174static 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 211static struct platform_driver max8907_rtc_driver = {212 .driver = {213 .name = "max8907-rtc",214 },215 .probe = max8907_rtc_probe,216};217module_platform_driver(max8907_rtc_driver);218 219MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");220MODULE_LICENSE("GPL v2");221