// SPDX-License-Identifier: GPL-2.0-only /* * RTC driver for Maxim MAX8907 * * Copyright (c) 2011-2012, NVIDIA Corporation. * * Based on drivers/rtc/rtc-max8925.c, * Copyright (C) 2009-2010 Marvell International Ltd. */ #include <linux/bcd.h> #include <linux/mfd/max8907.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/rtc.h> #include <linux/slab.h> enum { RTC_SEC = 0, RTC_MIN, RTC_HOUR, RTC_WEEKDAY, RTC_DATE, RTC_MONTH, RTC_YEAR1, RTC_YEAR2, }; #define TIME_NUM 8 #define ALARM_1SEC (1 << 7) #define HOUR_12 (1 << 7) #define HOUR_AM_PM (1 << 5) #define ALARM0_IRQ (1 << 3) #define ALARM1_IRQ (1 << 2) #define ALARM0_STATUS (1 << 2) #define ALARM1_STATUS (1 << 1) struct max8907_rtc { struct max8907 *max8907; struct regmap *regmap; struct rtc_device *rtc_dev; int irq; }; static irqreturn_t max8907_irq_handler(int irq, void *data) { struct max8907_rtc *rtc = data; regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF); return IRQ_HANDLED; } static void regs_to_tm(u8 *regs, struct rtc_time *tm) { tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 + bcd2bin(regs[RTC_YEAR1]) - 1900; tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1; tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f); tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07); if (regs[RTC_HOUR] & HOUR_12) { tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f); if (tm->tm_hour == 12) tm->tm_hour = 0; if (regs[RTC_HOUR] & HOUR_AM_PM) tm->tm_hour += 12; } else { tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f); } tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f); tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f); } static void tm_to_regs(struct rtc_time *tm, u8 *regs) { u8 high, low; high = (tm->tm_year + 1900) / 100; low = tm->tm_year % 100; regs[RTC_YEAR2] = bin2bcd(high); regs[RTC_YEAR1] = bin2bcd(low); regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1); regs[RTC_DATE] = bin2bcd(tm->tm_mday); regs[RTC_WEEKDAY] = tm->tm_wday; regs[RTC_HOUR] = bin2bcd(tm->tm_hour); regs[RTC_MIN] = bin2bcd(tm->tm_min); regs[RTC_SEC] = bin2bcd(tm->tm_sec); } static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct max8907_rtc *rtc = dev_get_drvdata(dev); u8 regs[TIME_NUM]; int ret; ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs, TIME_NUM); if (ret < 0) return ret; regs_to_tm(regs, tm); return 0; } static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct max8907_rtc *rtc = dev_get_drvdata(dev); u8 regs[TIME_NUM]; tm_to_regs(tm, regs); return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs, TIME_NUM); } static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct max8907_rtc *rtc = dev_get_drvdata(dev); u8 regs[TIME_NUM]; unsigned int val; int ret; ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, TIME_NUM); if (ret < 0) return ret; regs_to_tm(regs, &alrm->time); ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val); if (ret < 0) return ret; alrm->enabled = !!(val & 0x7f); return 0; } static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct max8907_rtc *rtc = dev_get_drvdata(dev); u8 regs[TIME_NUM]; int ret; tm_to_regs(&alrm->time, regs); /* Disable alarm while we update the target time */ ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0); if (ret < 0) return ret; ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs, TIME_NUM); if (ret < 0) return ret; if (alrm->enabled) ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77); return ret; } static const struct rtc_class_ops max8907_rtc_ops = { .read_time = max8907_rtc_read_time, .set_time = max8907_rtc_set_time, .read_alarm = max8907_rtc_read_alarm, .set_alarm = max8907_rtc_set_alarm, }; static int max8907_rtc_probe(struct platform_device *pdev) { struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent); struct max8907_rtc *rtc; int ret; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; platform_set_drvdata(pdev, rtc); rtc->max8907 = max8907; rtc->regmap = max8907->regmap_rtc; rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc", &max8907_rtc_ops, THIS_MODULE); if (IS_ERR(rtc->rtc_dev)) { ret = PTR_ERR(rtc->rtc_dev); dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret); return ret; } rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc, MAX8907_IRQ_RTC_ALARM0); if (rtc->irq < 0) return rtc->irq; ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, max8907_irq_handler, IRQF_ONESHOT, "max8907-alarm0", rtc); if (ret < 0) dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n", rtc->irq, ret); return ret; } static struct platform_driver max8907_rtc_driver = { .driver = { .name = "max8907-rtc", }, .probe = max8907_rtc_probe, }; module_platform_driver(max8907_rtc_driver); MODULE_DESCRIPTION("Maxim MAX8907 RTC driver"); MODULE_LICENSE("GPL v2");