[v2,5/5] rtc: rtc-rc5t619: add ricoh rc5t619 RTC driver
diff mbox series

Message ID 20191031213835.11390-6-andreas@kemnade.info
State Superseded
Headers show
Series
  • Add rtc support for rn5t618 mfd
Related show

Commit Message

Andreas Kemnade Oct. 31, 2019, 9:38 p.m. UTC
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: Andreas Kemnade <andreas@kemnade.info>
---
Changes in v2:
- correct subject line
- reset pon flag not at probe but later
- initialize things only on pon
- 12h handling
- ranges
- style cleanup
- less magic values

 drivers/rtc/Kconfig       |  10 +
 drivers/rtc/Makefile      |   1 +
 drivers/rtc/rtc-rc5t619.c | 488 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 499 insertions(+)
 create mode 100644 drivers/rtc/rtc-rc5t619.c

Comments

Alexandre Belloni Nov. 28, 2019, 10:57 a.m. UTC | #1
Hello,

checkpatch.pl --strict complains about multiple blank lines and alignment.

On 31/10/2019 22:38:35+0100, Andreas Kemnade wrote:
> +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;
> +	uint8_t alarm_flag;
> +	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) {
> +		dev_err(dev, "no irq specified, wakeup is disabled\n");

I don't think it is worth having an error message here, especially since
you have a second one later.

> +		rtc->irq = -1;
> +	}
> +
> +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
> +	if (err < 0)
> +		return err;
> +
> +	/* get interrupt flag */
> +	err = rc5t619_rtc_alarm_is_enabled(dev, &alarm_flag);
> +	if (err)
> +		return err;
> +
> +	/* disable rtc periodic function */
> +	err = rc5t619_rtc_periodic_disable(&pdev->dev);
> +	if (err)
> +		return err;
> +
> +	/* disable interrupt */
> +	err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> +	if (err)
> +		return err;

Is it really useful to disable the alarm to reenable them later?

> +
> +	if (ctrl2 & CTRL2_PON) {
> +		alarm_flag = 0;
> +		err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
> +		if (err)
> +			return err;
> +	}
> +
> +	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
> +

Please remove this blank line.

> +	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) {
> +		device_init_wakeup(&pdev->dev, 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 */

I think you should move device_init_wakeup() here, unless your parse the
wakeup-source property.

> +			enable_irq_wake(rtc->irq);
> +			/* enable alarm_d */
> +			err = rc5t619_rtc_alarm_enable(&pdev->dev, alarm_flag);
> +			if (err) {
> +				dev_err(&pdev->dev, "failed rtc setup\n");
> +				return -EBUSY;
> +			}
> +		}
> +	} else {
> +		/* system don't want to using alarm interrupt, so close it */
> +		err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> +		if (err) {
> +			dev_err(&pdev->dev, "disable rtc alarm error\n");

I don't think this message is necessary.

> +			return err;
> +		}
> +
> +		dev_err(&pdev->dev, "ricoh61x interrupt is disabled\n");

Maybe dev_warn as the driver just continues on.

> +	}
> +
> +	return rtc_register_device(rtc->rtc);
> +}
Andreas Kemnade Nov. 29, 2019, 6:59 a.m. UTC | #2
Hi,

On Thu, 28 Nov 2019 11:57:51 +0100
Alexandre Belloni <alexandre.belloni@bootlin.com> wrote:

> Hello,
> 
> checkpatch.pl --strict complains about multiple blank lines and alignment.
> 
I have not used the strict flag there. But I think I can make
--strict happy.

> On 31/10/2019 22:38:35+0100, Andreas Kemnade wrote:
> > +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;
> > +	uint8_t alarm_flag;
> > +	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) {
> > +		dev_err(dev, "no irq specified, wakeup is disabled\n");  
> 
> I don't think it is worth having an error message here, especially since
> you have a second one later.
> 
agreed.

> > +		rtc->irq = -1;
> > +	}
> > +
> > +	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
> > +	if (err < 0)
> > +		return err;
> > +
> > +	/* get interrupt flag */
> > +	err = rc5t619_rtc_alarm_is_enabled(dev, &alarm_flag);
> > +	if (err)
> > +		return err;
> > +
> > +	/* disable rtc periodic function */
> > +	err = rc5t619_rtc_periodic_disable(&pdev->dev);
> > +	if (err)
> > +		return err;
> > +
> > +	/* disable interrupt */
> > +	err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> > +	if (err)
> > +		return err;  
> 
> Is it really useful to disable the alarm to reenable them later?
> 
Well, yes, seems to be nonsense.
Am I right that I do not need to prevent alarm irqs between
alloc() and register()?

> > +
> > +	if (ctrl2 & CTRL2_PON) {
> > +		alarm_flag = 0;
> > +		err = rc5t619_rtc_alarm_flag_clr(&pdev->dev);
> > +		if (err)
> > +			return err;
> > +	}
> > +
> > +	rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
> > +  
> 
> Please remove this blank line.
> 
Ok.

> > +	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) {
> > +		device_init_wakeup(&pdev->dev, 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 */  
> 
> I think you should move device_init_wakeup() here, unless your parse
> the wakeup-source property.
> 
yes, makes sense.

> > +			enable_irq_wake(rtc->irq);
> > +			/* enable alarm_d */
> > +			err = rc5t619_rtc_alarm_enable(&pdev->dev,
> > alarm_flag);
> > +			if (err) {
> > +				dev_err(&pdev->dev, "failed rtc
> > setup\n");
> > +				return -EBUSY;
> > +			}
> > +		}
> > +	} else {
> > +		/* system don't want to using alarm interrupt, so
> > close it */
> > +		err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> > +		if (err) {
> > +			dev_err(&pdev->dev, "disable rtc alarm
> > error\n");  
> 
> I don't think this message is necessary.
> 
yes, agreed, that would be just another symptom of an i2c problem.
> > +			return err;
> > +		}
> > +
> > +		dev_err(&pdev->dev, "ricoh61x interrupt is
> > disabled\n");  
> 
> Maybe dev_warn as the driver just continues on.
> 
Ok.

Regards,
Andreas
Alexandre Belloni Nov. 29, 2019, 8:55 a.m. UTC | #3
On 29/11/2019 07:59:40+0100, Andreas Kemnade wrote:
> > > +	/* disable interrupt */
> > > +	err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> > > +	if (err)
> > > +		return err;  
> > 
> > Is it really useful to disable the alarm to reenable them later?
> > 
> Well, yes, seems to be nonsense.
> Am I right that I do not need to prevent alarm irqs between
> alloc() and register()?
> 

That's fine, the core will be ready to handle alarms after alloc()
Andreas Kemnade Nov. 29, 2019, 11:25 a.m. UTC | #4
On Fri, 29 Nov 2019 09:55:00 +0100
Alexandre Belloni <alexandre.belloni@bootlin.com> wrote:

> On 29/11/2019 07:59:40+0100, Andreas Kemnade wrote:
> > > > +	/* disable interrupt */
> > > > +	err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
> > > > +	if (err)
> > > > +		return err;    
> > > 
> > > Is it really useful to disable the alarm to reenable them later?
> > >   
> > Well, yes, seems to be nonsense.
> > Am I right that I do not need to prevent alarm irqs between
> > alloc() and register()?
> >   
> 
> That's fine, the core will be ready to handle alarms after alloc()
> 
ok, will clean that up and probably produce a -v3 this evening.

Regards,
Andreas

Patch
diff mbox series

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 1adf9f815652..b8e5bfa8efc6 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -600,6 +600,16 @@  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
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4ac8f19fb631..7612912cdf00 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -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
diff --git a/drivers/rtc/rtc-rc5t619.c b/drivers/rtc/rtc-rc5t619.c
new file mode 100644
index 000000000000..903bb9f9d96b
--- /dev/null
+++ b/drivers/rtc/rtc-rc5t619.c
@@ -0,0 +1,488 @@ 
+// 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;
+}
+
+static int rc5t619_rtc_alarm_is_enabled(struct device *dev,  uint8_t *enabled)
+{
+	struct rc5t619_rtc *rtc = dev_get_drvdata(dev);
+	int err;
+	unsigned int reg_data;
+
+	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL1, &reg_data);
+	if (err)
+		return err;
+
+	if (reg_data & CTRL1_ALARM_ENABLED)
+		*enabled = 1;
+	else
+		*enabled = 0;
+
+	return err;
+}
+
+/* 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;
+	uint8_t alarm_flag;
+	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) {
+		dev_err(dev, "no irq specified, wakeup is disabled\n");
+		rtc->irq = -1;
+	}
+
+	err = regmap_read(rtc->rn5t618->regmap, RN5T618_RTC_CTRL2, &ctrl2);
+	if (err < 0)
+		return err;
+
+	/* get interrupt flag */
+	err = rc5t619_rtc_alarm_is_enabled(dev, &alarm_flag);
+	if (err)
+		return err;
+
+	/* disable rtc periodic function */
+	err = rc5t619_rtc_periodic_disable(&pdev->dev);
+	if (err)
+		return err;
+
+	/* disable interrupt */
+	err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
+	if (err)
+		return err;
+
+	if (ctrl2 & CTRL2_PON) {
+		alarm_flag = 0;
+		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) {
+		device_init_wakeup(&pdev->dev, 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 */
+			enable_irq_wake(rtc->irq);
+			/* enable alarm_d */
+			err = rc5t619_rtc_alarm_enable(&pdev->dev, alarm_flag);
+			if (err) {
+				dev_err(&pdev->dev, "failed rtc setup\n");
+				return -EBUSY;
+			}
+		}
+	} else {
+		/* system don't want to using alarm interrupt, so close it */
+		err = rc5t619_rtc_alarm_enable(&pdev->dev, 0);
+		if (err) {
+			dev_err(&pdev->dev, "disable rtc alarm error\n");
+			return err;
+		}
+
+		dev_err(&pdev->dev, "ricoh61x 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");