diff options
Diffstat (limited to 'drivers/rtc/rtc-rc5t619.c')
| -rw-r--r-- | drivers/rtc/rtc-rc5t619.c | 444 |
1 files changed, 444 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-rc5t619.c b/drivers/rtc/rtc-rc5t619.c new file mode 100644 index 000000000000..24e386ecbc7e --- /dev/null +++ b/drivers/rtc/rtc-rc5t619.c @@ -0,0 +1,444 @@ +// 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 (IS_ERR(rtc)) { + err = PTR_ERR(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 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"); |