Merge branches 'ib-mfd-iio-input-5.7' and 'ib-mfd-iio-rtc-5.7' into ibs-for-mfd-merged

10 files changed, 851 insertions, 11 deletions

diff --git a/Documentation/devicetree/bindings/mfd/rn5t618.txt b/Documentation/devicetree/bindings/mfd/rn5t618.txt
index b74e5e94d1cb..16778ea00dbc 100644
--- a/Documentation/devicetree/bindings/mfd/rn5t618.txt
+++ b/Documentation/devicetree/bindings/mfd/rn5t618.txt
@@ -15,6 +15,8 @@ Required properties:
  - reg: the I2C slave address of the device
 
 Optional properties:
+ - interrupts: interrupt mapping for IRQ
+   See Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
  - system-power-controller:
    See Documentation/devicetree/bindings/power/power-controller.txt
 
@@ -32,6 +34,8 @@ Example:
 	pmic@32 {
 		compatible = "ricoh,rn5t618";
 		reg = <0x32>;
+		interrupt-parent = <&gpio5>;
+		interrupts = <11 IRQ_TYPE_EDGE_FALLING>;
 		system-power-controller;
 
 		regulators {
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 82e33082958c..300904b93656 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -783,6 +783,16 @@ config RCAR_GYRO_ADC
 	  To compile this driver as a module, choose M here: the
 	  module will be called rcar-gyroadc.
 
+config RN5T618_ADC
+	tristate "ADC for the RN5T618/RC5T619 family of chips"
+	depends on MFD_RN5T618
+	help
+	  Say yes here to build support for the integrated ADC inside the
+	  RN5T618/619 series PMICs:
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rn5t618-adc.
+
 config ROCKCHIP_SARADC
 	tristate "Rockchip SARADC driver"
 	depends on ARCH_ROCKCHIP || (ARM && COMPILE_TEST)
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 919228900df9..b182d234f45a 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -74,6 +74,7 @@ obj-$(CONFIG_QCOM_VADC_COMMON) += qcom-vadc-common.o
 obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
 obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o
 obj-$(CONFIG_RCAR_GYRO_ADC) += rcar-gyroadc.o
+obj-$(CONFIG_RN5T618_ADC) += rn5t618-adc.o
 obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
 obj-$(CONFIG_SC27XX_ADC) += sc27xx_adc.o
 obj-$(CONFIG_SPEAR_ADC) += spear_adc.o
diff --git a/drivers/iio/adc/rn5t618-adc.c b/drivers/iio/adc/rn5t618-adc.c
new file mode 100644
index 000000000000..f21027e4e26a
--- /dev/null
+++ b/drivers/iio/adc/rn5t618-adc.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * ADC driver for the RICOH RN5T618 power management chip family
+ *
+ * Copyright (C) 2019 Andreas Kemnade
+ */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mfd/rn5t618.h>
+#include <linux/platform_device.h>
+#include <linux/completion.h>
+#include <linux/regmap.h>
+#include <linux/iio/iio.h>
+#include <linux/slab.h>
+
+#define RN5T618_ADC_CONVERSION_TIMEOUT   (msecs_to_jiffies(500))
+#define RN5T618_REFERENCE_VOLT 2500
+
+/* mask for selecting channels for single conversion */
+#define RN5T618_ADCCNT3_CHANNEL_MASK 0x7
+/* average 4-time conversion mode */
+#define RN5T618_ADCCNT3_AVG BIT(3)
+/* set for starting a single conversion, gets cleared by hw when done */
+#define RN5T618_ADCCNT3_GODONE BIT(4)
+/* automatic conversion, period is in ADCCNT2, selected channels are
+ * in ADCCNT1
+ */
+#define RN5T618_ADCCNT3_AUTO BIT(5)
+#define RN5T618_ADCEND_IRQ BIT(0)
+
+struct rn5t618_adc_data {
+	struct device *dev;
+	struct rn5t618 *rn5t618;
+	struct completion conv_completion;
+	int irq;
+};
+
+struct rn5t618_channel_ratios {
+	u16 numerator;
+	u16 denominator;
+};
+
+enum rn5t618_channels {
+	LIMMON = 0,
+	VBAT,
+	VADP,
+	VUSB,
+	VSYS,
+	VTHM,
+	AIN1,
+	AIN0
+};
+
+static const struct rn5t618_channel_ratios rn5t618_ratios[8] = {
+	[LIMMON] = {50, 32}, /* measured across 20mOhm, amplified by 32 */
+	[VBAT] = {2, 1},
+	[VADP] = {3, 1},
+	[VUSB] = {3, 1},
+	[VSYS] = {3, 1},
+	[VTHM] = {1, 1},
+	[AIN1] = {1, 1},
+	[AIN0] = {1, 1},
+};
+
+static int rn5t618_read_adc_reg(struct rn5t618 *rn5t618, int reg, u16 *val)
+{
+	u8 data[2];
+	int ret;
+
+	ret = regmap_bulk_read(rn5t618->regmap, reg, data, sizeof(data));
+	if (ret < 0)
+		return ret;
+
+	*val = (data[0] << 4) | (data[1] & 0xF);
+
+	return 0;
+}
+
+static irqreturn_t rn5t618_adc_irq(int irq, void *data)
+{
+	struct rn5t618_adc_data *adc = data;
+	unsigned int r = 0;
+	int ret;
+
+	/* clear low & high threshold irqs */
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC1, 0);
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC2, 0);
+
+	ret = regmap_read(adc->rn5t618->regmap, RN5T618_IR_ADC3, &r);
+	if (ret < 0)
+		dev_err(adc->dev, "failed to read IRQ status: %d\n", ret);
+
+	regmap_write(adc->rn5t618->regmap, RN5T618_IR_ADC3, 0);
+
+	if (r & RN5T618_ADCEND_IRQ)
+		complete(&adc->conv_completion);
+
+	return IRQ_HANDLED;
+}
+
+static int rn5t618_adc_read(struct iio_dev *iio_dev,
+			    const struct iio_chan_spec *chan,
+			    int *val, int *val2, long mask)
+{
+	struct rn5t618_adc_data *adc = iio_priv(iio_dev);
+	u16 raw;
+	int ret;
+
+	if (mask == IIO_CHAN_INFO_SCALE) {
+		*val = RN5T618_REFERENCE_VOLT *
+		       rn5t618_ratios[chan->channel].numerator;
+		*val2 = rn5t618_ratios[chan->channel].denominator * 4095;
+
+		return IIO_VAL_FRACTIONAL;
+	}
+
+	/* select channel */
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_CHANNEL_MASK,
+				 chan->channel);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_write(adc->rn5t618->regmap, RN5T618_EN_ADCIR3,
+			   RN5T618_ADCEND_IRQ);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_AVG,
+				 mask == IIO_CHAN_INFO_AVERAGE_RAW ?
+				 RN5T618_ADCCNT3_AVG : 0);
+	if (ret < 0)
+		return ret;
+
+	init_completion(&adc->conv_completion);
+	/* single conversion */
+	ret = regmap_update_bits(adc->rn5t618->regmap, RN5T618_ADCCNT3,
+				 RN5T618_ADCCNT3_GODONE,
+				 RN5T618_ADCCNT3_GODONE);
+	if (ret < 0)
+		return ret;
+
+	ret = wait_for_completion_timeout(&adc->conv_completion,
+					  RN5T618_ADC_CONVERSION_TIMEOUT);
+	if (ret == 0) {
+		dev_warn(adc->dev, "timeout waiting for adc result\n");
+		return -ETIMEDOUT;
+	}
+
+	ret = rn5t618_read_adc_reg(adc->rn5t618,
+				   RN5T618_ILIMDATAH + 2 * chan->channel,
+				   &raw);
+	if (ret < 0)
+		return ret;
+
+	*val = raw;
+
+	return IIO_VAL_INT;
+}
+
+static const struct iio_info rn5t618_adc_iio_info = {
+	.read_raw = &rn5t618_adc_read,
+};
+
+#define RN5T618_ADC_CHANNEL(_channel, _type, _name) { \
+	.type = _type, \
+	.channel = _channel, \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+			      BIT(IIO_CHAN_INFO_AVERAGE_RAW) | \
+			      BIT(IIO_CHAN_INFO_SCALE), \
+	.datasheet_name = _name, \
+	.indexed = 1. \
+}
+
+static const struct iio_chan_spec rn5t618_adc_iio_channels[] = {
+	RN5T618_ADC_CHANNEL(LIMMON, IIO_CURRENT, "LIMMON"),
+	RN5T618_ADC_CHANNEL(VBAT, IIO_VOLTAGE, "VBAT"),
+	RN5T618_ADC_CHANNEL(VADP, IIO_VOLTAGE, "VADP"),
+	RN5T618_ADC_CHANNEL(VUSB, IIO_VOLTAGE, "VUSB"),
+	RN5T618_ADC_CHANNEL(VSYS, IIO_VOLTAGE, "VSYS"),
+	RN5T618_ADC_CHANNEL(VTHM, IIO_VOLTAGE, "VTHM"),
+	RN5T618_ADC_CHANNEL(AIN1, IIO_VOLTAGE, "AIN1"),
+	RN5T618_ADC_CHANNEL(AIN0, IIO_VOLTAGE, "AIN0")
+};
+
+static int rn5t618_adc_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct iio_dev *iio_dev;
+	struct rn5t618_adc_data *adc;
+	struct rn5t618 *rn5t618 = dev_get_drvdata(pdev->dev.parent);
+
+	iio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
+	if (!iio_dev) {
+		dev_err(&pdev->dev, "failed allocating iio device\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(iio_dev);
+	adc->dev = &pdev->dev;
+	adc->rn5t618 = rn5t618;
+
+	if (rn5t618->irq_data)
+		adc->irq = regmap_irq_get_virq(rn5t618->irq_data,
+					       RN5T618_IRQ_ADC);
+
+	if (adc->irq <= 0) {
+		dev_err(&pdev->dev, "get virq failed\n");
+		return -EINVAL;
+	}
+
+	init_completion(&adc->conv_completion);
+
+	iio_dev->name = dev_name(&pdev->dev);
+	iio_dev->dev.parent = &pdev->dev;
+	iio_dev->info = &rn5t618_adc_iio_info;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+	iio_dev->channels = rn5t618_adc_iio_channels;
+	iio_dev->num_channels = ARRAY_SIZE(rn5t618_adc_iio_channels);
+
+	/* stop any auto-conversion */
+	ret = regmap_write(rn5t618->regmap, RN5T618_ADCCNT3, 0);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, iio_dev);
+
+	ret = devm_request_threaded_irq(adc->dev, adc->irq, NULL,
+					rn5t618_adc_irq,
+					IRQF_ONESHOT, dev_name(adc->dev),
+					adc);
+	if (ret < 0) {
+		dev_err(adc->dev, "request irq %d failed: %d\n", adc->irq, ret);
+		return ret;
+	}
+
+	return devm_iio_device_register(adc->dev, iio_dev);
+}
+
+static struct platform_driver rn5t618_adc_driver = {
+	.driver = {
+		.name   = "rn5t618-adc",
+	},
+	.probe = rn5t618_adc_probe,
+};
+
+module_platform_driver(rn5t618_adc_driver);
+MODULE_ALIAS("platform:rn5t618-adc");
+MODULE_DESCRIPTION("RICOH RN5T618 ADC driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index daefcb6310f9..da4a9a0c5ca2 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1071,6 +1071,7 @@ config MFD_RN5T618
 	depends on OF
 	select MFD_CORE
 	select REGMAP_I2C
+	select REGMAP_IRQ
 	help
 	  Say yes here to add support for the Ricoh RN5T567,
 	  RN5T618, RC5T619 PMIC.
diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
index ead2e79036a9..232de50562f9 100644
--- a/drivers/mfd/rn5t618.c
+++ b/drivers/mfd/rn5t618.c
@@ -8,10 +8,13 @@
 
 #include <linux/delay.h>
 #include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/rn5t618.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
+#include <linux/platform_device.h>
 #include <linux/reboot.h>
 #include <linux/regmap.h>
 
@@ -20,6 +23,13 @@ static const struct mfd_cell rn5t618_cells[] = {
 	{ .name = "rn5t618-wdt" },
 };
 
+static const struct mfd_cell rc5t619_cells[] = {
+	{ .name = "rn5t618-adc" },
+	{ .name = "rn5t618-regulator" },
+	{ .name = "rc5t619-rtc" },
+	{ .name = "rn5t618-wdt" },
+};
+
 static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
@@ -32,6 +42,8 @@ static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
 	case RN5T618_IR_GPF:
 	case RN5T618_MON_IOIN:
 	case RN5T618_INTMON:
+	case RN5T618_RTC_CTRL1 ... RN5T618_RTC_CTRL2:
+	case RN5T618_RTC_SECONDS ... RN5T618_RTC_YEAR:
 		return true;
 	default:
 		return false;
@@ -46,9 +58,56 @@ static const struct regmap_config rn5t618_regmap_config = {
 	.cache_type	= REGCACHE_RBTREE,
 };
 
+static const struct regmap_irq rc5t619_irqs[] = {
+	REGMAP_IRQ_REG(RN5T618_IRQ_SYS, 0, BIT(0)),
+	REGMAP_IRQ_REG(RN5T618_IRQ_DCDC, 0, BIT(1)),
+	REGMAP_IRQ_REG(RN5T618_IRQ_RTC, 0, BIT(2)),
+	REGMAP_IRQ_REG(RN5T618_IRQ_ADC, 0, BIT(3)),
+	REGMAP_IRQ_REG(RN5T618_IRQ_GPIO, 0, BIT(4)),
+	REGMAP_IRQ_REG(RN5T618_IRQ_CHG, 0, BIT(6)),
+};
+
+static const struct regmap_irq_chip rc5t619_irq_chip = {
+	.name = "rc5t619",
+	.irqs = rc5t619_irqs,
+	.num_irqs = ARRAY_SIZE(rc5t619_irqs),
+	.num_regs = 1,
+	.status_base = RN5T618_INTMON,
+	.mask_base = RN5T618_INTEN,
+	.mask_invert = true,
+};
+
 static struct rn5t618 *rn5t618_pm_power_off;
 static struct notifier_block rn5t618_restart_handler;
 
+static int rn5t618_irq_init(struct rn5t618 *rn5t618)
+{
+	const struct regmap_irq_chip *irq_chip = NULL;
+	int ret;
+
+	if (!rn5t618->irq)
+		return 0;
+
+	switch (rn5t618->variant) {
+	case RC5T619:
+		irq_chip = &rc5t619_irq_chip;
+		break;
+	default:
+		dev_err(rn5t618->dev, "Currently no IRQ support for variant %d\n",
+			(int)rn5t618->variant);
+		return -ENOENT;
+	}
+
+	ret = devm_regmap_add_irq_chip(rn5t618->dev, rn5t618->regmap,
+				       rn5t618->irq,
+				       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+				       0, irq_chip, &rn5t618->irq_data);
+	if (ret)
+		dev_err(rn5t618->dev, "Failed to register IRQ chip\n");
+
+	return ret;
+}
+
 static void rn5t618_trigger_poweroff_sequence(bool repower)
 {
 	/* disable automatic repower-on */
@@ -87,8 +146,7 @@ static const struct of_device_id rn5t618_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, rn5t618_of_match);
 
-static int rn5t618_i2c_probe(struct i2c_client *i2c,
-			     const struct i2c_device_id *id)
+static int rn5t618_i2c_probe(struct i2c_client *i2c)
 {
 	const struct of_device_id *of_id;
 	struct rn5t618 *priv;
@@ -106,6 +164,8 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
 
 	i2c_set_clientdata(i2c, priv);
 	priv->variant = (long)of_id->data;
+	priv->irq = i2c->irq;
+	priv->dev = &i2c->dev;
 
 	priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
 	if (IS_ERR(priv->regmap)) {
@@ -114,8 +174,16 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
 		return ret;
 	}
 
-	ret = devm_mfd_add_devices(&i2c->dev, -1, rn5t618_cells,
-				   ARRAY_SIZE(rn5t618_cells), NULL, 0, NULL);
+	if (priv->variant == RC5T619)
+		ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_NONE,
+					   rc5t619_cells,
+					   ARRAY_SIZE(rc5t619_cells),
+					   NULL, 0, NULL);
+	else
+		ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_NONE,
+					   rn5t618_cells,
+					   ARRAY_SIZE(rn5t618_cells),
+					   NULL, 0, NULL);
 	if (ret) {
 		dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
 		return ret;
@@ -138,7 +206,7 @@ static int rn5t618_i2c_probe(struct i2c_client *i2c,
 		return ret;
 	}
 
-	return 0;
+	return rn5t618_irq_init(priv);
 }
 
 static int rn5t618_i2c_remove(struct i2c_client *i2c)
@@ -155,19 +223,38 @@ static int rn5t618_i2c_remove(struct i2c_client *i2c)
 	return 0;
 }
 
-static const struct i2c_device_id rn5t618_i2c_id[] = {
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, rn5t618_i2c_id);
+static int __maybe_unused rn5t618_i2c_suspend(struct device *dev)
+{
+	struct rn5t618 *priv = dev_get_drvdata(dev);
+
+	if (priv->irq)
+		disable_irq(priv->irq);
+
+	return 0;
+}
+
+static int __maybe_unused rn5t618_i2c_resume(struct device *dev)
+{
+	struct rn5t618 *priv = dev_get_drvdata(dev);
+
+	if (priv->irq)
+		enable_irq(priv->irq);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(rn5t618_i2c_dev_pm_ops,
+			rn5t618_i2c_suspend,
+			rn5t618_i2c_resume);
 
 static struct i2c_driver rn5t618_i2c_driver = {
 	.driver = {
 		.name = "rn5t618",
 		.of_match_table = of_match_ptr(rn5t618_of_match),
+		.pm = &rn5t618_i2c_dev_pm_ops,
 	},
-	.probe = rn5t618_i2c_probe,
+	.probe_new = rn5t618_i2c_probe,
 	.remove = rn5t618_i2c_remove,
-	.id_table = rn5t618_i2c_id,
 };
 
 module_i2c_driver(rn5t618_i2c_driver);
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 34c8b6c7e095..72fed8dc55e8 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -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
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..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, &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");
diff --git a/include/linux/mfd/rn5t618.h b/include/linux/mfd/rn5t618.h
index d62ef48060b5..fba0df13d9a8 100644
--- a/include/linux/mfd/rn5t618.h
+++ b/include/linux/mfd/rn5t618.h
@@ -139,6 +139,17 @@
 #define RN5T618_INTPOL			0x9c
 #define RN5T618_INTEN			0x9d
 #define RN5T618_INTMON			0x9e
+
+#define RN5T618_RTC_SECONDS     0xA0
+#define RN5T618_RTC_MDAY        0xA4
+#define RN5T618_RTC_MONTH       0xA5
+#define RN5T618_RTC_YEAR        0xA6
+#define RN5T618_RTC_ADJUST      0xA7
+#define RN5T618_RTC_ALARM_Y_SEC 0xA8
+#define RN5T618_RTC_DAL_MONTH   0xAC
+#define RN5T618_RTC_CTRL1       0xAE
+#define RN5T618_RTC_CTRL2       0xAF
+
 #define RN5T618_PREVINDAC		0xb0
 #define RN5T618_BATDAC			0xb1
 #define RN5T618_CHGCTL1			0xb3
@@ -242,9 +253,24 @@ enum {
 	RC5T619,
 };
 
+/* RN5T618 IRQ definitions */
+enum {
+	RN5T618_IRQ_SYS = 0,
+	RN5T618_IRQ_DCDC,
+	RN5T618_IRQ_RTC,
+	RN5T618_IRQ_ADC,
+	RN5T618_IRQ_GPIO,
+	RN5T618_IRQ_CHG,
+	RN5T618_NR_IRQS,
+};
+
 struct rn5t618 {
 	struct regmap *regmap;
+	struct device *dev;
 	long variant;
+
+	int irq;
+	struct regmap_irq_chip_data *irq_data;
 };
 
 #endif /* __LINUX_MFD_RN5T618_H */