// SPDX-License-Identifier: GPL-2.0+ /* * drivers/rtc/rtc-rc5t619.c * * Real time clock driver for RICOH RC5T619 power management chip. * * Copyright (C) 2019 Andreas Kemnade */ #include <linux/kernel.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mfd/rn5t618.h> #include <linux/platform_device.h> #include <linux/regmap.h> #include <linux/bcd.h> #include <linux/rtc.h> #include <linux/slab.h> #include <linux/irqdomain.h> struct rc5t619_rtc { int irq; struct rtc_device *rtc; struct rn5t618 *rn5t618; }; #define CTRL1_ALARM_ENABLED 0x40 #define CTRL1_24HR 0x20 #define CTRL1_PERIODIC_MASK 0xf #define CTRL2_PON 0x10 #define CTRL2_ALARM_STATUS 0x80 #define CTRL2_CTFG 0x4 #define CTRL2_CTC 0x1 #define MONTH_CENTFLAG 0x80 #define HOUR_PMFLAG 0x20 #define MDAY_DAL_EXT 0x80 static uint8_t rtc5t619_12hour_bcd2bin(uint8_t hour) { if (hour & HOUR_PMFLAG) { hour = bcd2bin(hour & ~HOUR_PMFLAG); return hour == 12 ? 12 : 12 + hour; } hour = bcd2bin(hour); return hour == 12 ? 0 : hour; } static uint8_t rtc5t619_12hour_bin2bcd(uint8_t hour) { if (!hour) return 0x12; if (hour < 12) return bin2bcd(hour); if (hour == 12) return 0x12 | HOUR_PMFLAG; return bin2bcd(hour - 12) | HOUR_PMFLAG; } static int rc5t619_rtc_periodic_disable(struct device *dev) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); int err; /* disable function */ err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, CTRL1_PERIODIC_MASK, 0); if (err < 0) return err; /* clear alarm flag and CTFG */ err = regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, CTRL2_ALARM_STATUS | CTRL2_CTFG | CTRL2_CTC, 0); if (err < 0) return err; return 0; } /* things to be done once after power on */ static int rc5t619_rtc_pon_setup(struct device *dev) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); int err; unsigned int reg_data; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, ®_data); if (err < 0) return err; /* clear VDET PON */ reg_data &= ~(CTRL2_PON | CTRL2_CTC | 0x4a); /* 0101-1011 */ reg_data |= 0x20; /* 0010-0000 */ err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, reg_data); if (err < 0) return err; /* clearing RTC Adjust register */ err = regmap_write(rtc->rn5t618->regmap, RN5T618_RTC_ADJUST, 0); if (err) return err; return regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, CTRL1_24HR, CTRL1_24HR); } static int rc5t619_rtc_read_time(struct device *dev, struct rtc_time *tm) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); u8 buff[7]; int err; int cent_flag; unsigned int ctrl1; unsigned int ctrl2; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2); if (err < 0) return err; if (ctrl2 & CTRL2_PON) return -EINVAL; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1); if (err < 0) return err; err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS, buff, sizeof(buff)); if (err < 0) return err; if (buff[5] & MONTH_CENTFLAG) cent_flag = 1; else cent_flag = 0; tm->tm_sec = bcd2bin(buff[0]); tm->tm_min = bcd2bin(buff[1]); if (ctrl1 & CTRL1_24HR) tm->tm_hour = bcd2bin(buff[2]); else tm->tm_hour = rtc5t619_12hour_bcd2bin(buff[2]); tm->tm_wday = bcd2bin(buff[3]); tm->tm_mday = bcd2bin(buff[4]); tm->tm_mon = bcd2bin(buff[5] & 0x1f) - 1; /* back to system 0-11 */ tm->tm_year = bcd2bin(buff[6]) + 100 * cent_flag; return 0; } static int rc5t619_rtc_set_time(struct device *dev, struct rtc_time *tm) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); u8 buff[7]; int err; int cent_flag; unsigned int ctrl1; unsigned int ctrl2; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2); if (err < 0) return err; if (ctrl2 & CTRL2_PON) rc5t619_rtc_pon_setup(dev); err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1); if (err < 0) return err; if (tm->tm_year >= 100) cent_flag = 1; else cent_flag = 0; buff[0] = bin2bcd(tm->tm_sec); buff[1] = bin2bcd(tm->tm_min); if (ctrl1 & CTRL1_24HR) buff[2] = bin2bcd(tm->tm_hour); else buff[2] = rtc5t619_12hour_bin2bcd(tm->tm_hour); buff[3] = bin2bcd(tm->tm_wday); buff[4] = bin2bcd(tm->tm_mday); buff[5] = bin2bcd(tm->tm_mon + 1); /* system set 0-11 */ buff[6] = bin2bcd(tm->tm_year - cent_flag * 100); if (cent_flag) buff[5] |= MONTH_CENTFLAG; err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_SECONDS, buff, sizeof(buff)); if (err < 0) { dev_err(dev, "failed to program new time: %d\n", err); return err; } return 0; } /* 0-disable, 1-enable */ static int rc5t619_rtc_alarm_enable(struct device *dev, unsigned int enabled) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); return regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, CTRL1_ALARM_ENABLED, enabled ? CTRL1_ALARM_ENABLED : 0); } static int rc5t619_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); u8 buff[6]; unsigned int buff_cent; int err; int cent_flag; unsigned int ctrl1; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1); if (err) return err; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_MONTH, &buff_cent); if (err < 0) { dev_err(dev, "failed to read time: %d\n", err); return err; } if (buff_cent & MONTH_CENTFLAG) cent_flag = 1; else cent_flag = 0; err = regmap_bulk_read(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC, buff, sizeof(buff)); if (err) return err; buff[3] = buff[3] & 0x3f; alrm->time.tm_sec = bcd2bin(buff[0]); alrm->time.tm_min = bcd2bin(buff[1]); if (ctrl1 & CTRL1_24HR) alrm->time.tm_hour = bcd2bin(buff[2]); else alrm->time.tm_hour = rtc5t619_12hour_bcd2bin(buff[2]); alrm->time.tm_mday = bcd2bin(buff[3]); alrm->time.tm_mon = bcd2bin(buff[4]) - 1; alrm->time.tm_year = bcd2bin(buff[5]) + 100 * cent_flag; alrm->enabled = !!(ctrl1 & CTRL1_ALARM_ENABLED); dev_dbg(dev, "read alarm: %ptR\n", &alrm->time); return 0; } static int rc5t619_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); u8 buff[6]; int err; int cent_flag; unsigned int ctrl1; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &ctrl1); if (err) return err; err = rc5t619_rtc_alarm_enable(dev, 0); if (err < 0) return err; if (rtc->irq == -1) return -EINVAL; if (alrm->enabled == 0) return 0; if (alrm->time.tm_year >= 100) cent_flag = 1; else cent_flag = 0; alrm->time.tm_mon += 1; buff[0] = bin2bcd(alrm->time.tm_sec); buff[1] = bin2bcd(alrm->time.tm_min); if (ctrl1 & CTRL1_24HR) buff[2] = bin2bcd(alrm->time.tm_hour); else buff[2] = rtc5t619_12hour_bin2bcd(alrm->time.tm_hour); buff[3] = bin2bcd(alrm->time.tm_mday); buff[4] = bin2bcd(alrm->time.tm_mon); buff[5] = bin2bcd(alrm->time.tm_year - 100 * cent_flag); buff[3] |= MDAY_DAL_EXT; err = regmap_bulk_write(rtc->rn5t618->regmap, RN5T618_RTC_ALARM_Y_SEC, buff, sizeof(buff)); if (err < 0) return err; return rc5t619_rtc_alarm_enable(dev, alrm->enabled); } static const struct rtc_class_ops rc5t619_rtc_ops = { .read_time = rc5t619_rtc_read_time, .set_time = rc5t619_rtc_set_time, .set_alarm = rc5t619_rtc_set_alarm, .read_alarm = rc5t619_rtc_read_alarm, .alarm_irq_enable = rc5t619_rtc_alarm_enable, }; static int rc5t619_rtc_alarm_flag_clr(struct device *dev) { struct rc5t619_rtc *rtc = dev_get_drvdata(dev); /* clear alarm-D status bits.*/ return regmap_update_bits(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, CTRL2_ALARM_STATUS | CTRL2_CTC, 0); } static irqreturn_t rc5t619_rtc_irq(int irq, void *data) { struct device *dev = data; struct rc5t619_rtc *rtc = dev_get_drvdata(dev); rc5t619_rtc_alarm_flag_clr(dev); rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF); return IRQ_HANDLED; } static int rc5t619_rtc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent); struct rc5t619_rtc *rtc; unsigned int ctrl2; int err; rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) return -ENOMEM; rtc->rn5t618 = rn5t618; dev_set_drvdata(dev, rtc); rtc->irq = -1; if (rn5t618->irq_data) rtc->irq = regmap_irq_get_virq(rn5t618->irq_data, RN5T618_IRQ_RTC); if (rtc->irq < 0) rtc->irq = -1; err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2); if (err < 0) return err; /* disable rtc periodic function */ err = rc5t619_rtc_periodic_disable(&pdev->dev); if (err) return err; if (ctrl2 & CTRL2_PON) { err = rc5t619_rtc_alarm_flag_clr(&pdev->dev); if (err) return err; } rtc->rtc = devm_rtc_allocate_device(&pdev->dev); if (IS_ERR(rtc->rtc)) { err = PTR_ERR(rtc->rtc); dev_err(dev, "RTC device register: err %d\n", err); return err; } rtc->rtc->ops = &rc5t619_rtc_ops; rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_1900; rtc->rtc->range_max = RTC_TIMESTAMP_END_2099; /* set interrupt and enable it */ if (rtc->irq != -1) { err = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL, rc5t619_rtc_irq, IRQF_ONESHOT, "rtc-rc5t619", &pdev->dev); if (err < 0) { dev_err(&pdev->dev, "request IRQ:%d fail\n", rtc->irq); rtc->irq = -1; err = rc5t619_rtc_alarm_enable(&pdev->dev, 0); if (err) return err; } else { /* enable wake */ device_init_wakeup(&pdev->dev, 1); enable_irq_wake(rtc->irq); } } else { /* system don't want to using alarm interrupt, so close it */ err = rc5t619_rtc_alarm_enable(&pdev->dev, 0); if (err) return err; dev_warn(&pdev->dev, "rc5t619 interrupt is disabled\n"); } return devm_rtc_register_device(rtc->rtc); } static struct platform_driver rc5t619_rtc_driver = { .driver = { .name = "rc5t619-rtc", }, .probe = rc5t619_rtc_probe, }; module_platform_driver(rc5t619_rtc_driver); MODULE_ALIAS("platform:rc5t619-rtc"); MODULE_DESCRIPTION("RICOH RC5T619 RTC driver"); MODULE_LICENSE("GPL");