Commit 540d1e15 authored by Andreas Kemnade's avatar Andreas Kemnade Committed by Lee Jones
Browse files

rtc: rc5t619: Add Ricoh RC5T619 RTC driver 



Add an RTC driver for the RTC device on Ricoh MFD RC5T619,
which is implemented as a variant of RN5T618.

rtc-range output:
Testing 2000-02-28 23:59:59.
OK

Testing 2038-01-19 03:14:07.
OK

Testing 2069-12-31 23:59:59.
OK

Testing 2099-12-31 23:59:59.
KO RTC_RD_TIME returned 22 (line 138)

Testing 2100-02-28 23:59:59.
KO RTC_SET_TIME returned 34 (line 122)

Testing 2106-02-07 06:28:15.
KO RTC_SET_TIME returned 34 (line 122)

Testing 2262-04-11 23:47:16.
KO RTC_SET_TIME returned 34 (line 122)

Signed-off-by: default avatarAndreas Kemnade <andreas@kemnade.info>
Acked-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent bc616766

drivers/rtc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -591,6 +591,16 @@ config RTC_DRV_RC5T583 
	  This driver can also be built as a module. If so, the module

	  will be called rtc-rc5t583.



config RTC_DRV_RC5T619

	tristate "RICOH RC5T619 RTC driver"

	depends on MFD_RN5T618

	help

	  If you say yes here you get support for the RTC on the

	  RICOH RC5T619 chips.



	  This driver can also be built as a module. If so, the module

	  will be called rtc-rc5t619.



config RTC_DRV_S35390A

	tristate "Seiko Instruments S-35390A"

	select BITREVERSE

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o 
obj-$(CONFIG_RTC_DRV_R7301)	+= rtc-r7301.o

obj-$(CONFIG_RTC_DRV_R9701)	+= rtc-r9701.o

obj-$(CONFIG_RTC_DRV_RC5T583)	+= rtc-rc5t583.o

obj-$(CONFIG_RTC_DRV_RC5T619)	+= rtc-rc5t619.o

obj-$(CONFIG_RTC_DRV_RK808)	+= rtc-rk808.o

obj-$(CONFIG_RTC_DRV_RP5C01)	+= rtc-rp5c01.o

obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o

drivers/rtc/rtc-rc5t619.c

0 → 100644
+444 −0
Original line number Diff line number Diff line 
// 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, &reg_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");

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