iio:adc: add iio driver for Palmas (twl6035/7) gpadc

This driver code was found as:

https://android.googlesource.com/kernel/tegra/+/aaabb2e045f31e5a970109ffdaae900dd403d17e/drivers/staging/iio/adc

Fixed various compilation issues and test this driver on omap5 evm.

Signed-off-by: Pradeep Goudagunta <pgoudagunta@nvidia.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Marek Belisko <marek@goldelico.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 826 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7868c744fd4b..daad72e1266d 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -275,6 +275,14 @@ config NAU7802
 	  To compile this driver as a module, choose M here: the
 	  module will be called nau7802.
 
+config PALMAS_GPADC
+	tristate "TI Palmas General Purpose ADC"
+	depends on MFD_PALMAS
+	help
+	  Palmas series pmic chip by Texas Instruments (twl6035/6037)
+	  is used in smartphones and tablets and supports a 16 channel
+	  general purpose ADC.
+
 config QCOM_SPMI_IADC
 	tristate "Qualcomm SPMI PMIC current ADC"
 	depends on SPMI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 99b37a963a1e..11cfdfd76798 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
 obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
+obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
 obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
 obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-spmi-vadc.o
 obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
diff --git a/drivers/iio/adc/palmas_gpadc.c b/drivers/iio/adc/palmas_gpadc.c
new file mode 100644
index 000000000000..71763c5da2ab
--- /dev/null
+++ b/drivers/iio/adc/palmas_gpadc.c
@@ -0,0 +1,817 @@
+/*
+ * palmas-adc.c -- TI PALMAS GPADC.
+ *
+ * Copyright (c) 2013, NVIDIA Corporation. All rights reserved.
+ *
+ * Author: Pradeep Goudagunta <pgoudagunta@nvidia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ */
+
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/pm.h>
+#include <linux/mfd/palmas.h>
+#include <linux/completion.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/machine.h>
+#include <linux/iio/driver.h>
+
+#define MOD_NAME "palmas-gpadc"
+#define PALMAS_ADC_CONVERSION_TIMEOUT	(msecs_to_jiffies(5000))
+#define PALMAS_TO_BE_CALCULATED 0
+#define PALMAS_GPADC_TRIMINVALID	-1
+
+struct palmas_gpadc_info {
+/* calibration codes and regs */
+	int x1;	/* lower ideal code */
+	int x2;	/* higher ideal code */
+	int v1;	/* expected lower volt reading */
+	int v2;	/* expected higher volt reading */
+	u8 trim1_reg;	/* register number for lower trim */
+	u8 trim2_reg;	/* register number for upper trim */
+	int gain;	/* calculated from above (after reading trim regs) */
+	int offset;	/* calculated from above (after reading trim regs) */
+	int gain_error;	/* calculated from above (after reading trim regs) */
+	bool is_uncalibrated;	/* if channel has calibration data */
+};
+
+#define PALMAS_ADC_INFO(_chan, _x1, _x2, _v1, _v2, _t1, _t2, _is_uncalibrated) \
+	[PALMAS_ADC_CH_##_chan] = { \
+		.x1 = _x1, \
+		.x2 = _x2, \
+		.v1 = _v1, \
+		.v2 = _v2, \
+		.gain = PALMAS_TO_BE_CALCULATED, \
+		.offset = PALMAS_TO_BE_CALCULATED, \
+		.gain_error = PALMAS_TO_BE_CALCULATED, \
+		.trim1_reg = PALMAS_GPADC_TRIM##_t1, \
+		.trim2_reg = PALMAS_GPADC_TRIM##_t2,  \
+		.is_uncalibrated = _is_uncalibrated \
+	}
+
+static struct palmas_gpadc_info palmas_gpadc_info[] = {
+	PALMAS_ADC_INFO(IN0, 2064, 3112, 630, 950, 1, 2, false),
+	PALMAS_ADC_INFO(IN1, 2064, 3112, 630, 950, 1, 2, false),
+	PALMAS_ADC_INFO(IN2, 2064, 3112, 1260, 1900, 3, 4, false),
+	PALMAS_ADC_INFO(IN3, 2064, 3112, 630, 950, 1, 2, false),
+	PALMAS_ADC_INFO(IN4, 2064, 3112, 630, 950, 1, 2, false),
+	PALMAS_ADC_INFO(IN5, 2064, 3112, 630, 950, 1, 2, false),
+	PALMAS_ADC_INFO(IN6, 2064, 3112, 2520, 3800, 5, 6, false),
+	PALMAS_ADC_INFO(IN7, 2064, 3112, 2520, 3800, 7, 8, false),
+	PALMAS_ADC_INFO(IN8, 2064, 3112, 3150, 4750, 9, 10, false),
+	PALMAS_ADC_INFO(IN9, 2064, 3112, 5670, 8550, 11, 12, false),
+	PALMAS_ADC_INFO(IN10, 2064, 3112, 3465, 5225, 13, 14, false),
+	PALMAS_ADC_INFO(IN11, 0, 0, 0, 0, INVALID, INVALID, true),
+	PALMAS_ADC_INFO(IN12, 0, 0, 0, 0, INVALID, INVALID, true),
+	PALMAS_ADC_INFO(IN13, 0, 0, 0, 0, INVALID, INVALID, true),
+	PALMAS_ADC_INFO(IN14, 2064, 3112, 3645, 5225, 15, 16, false),
+	PALMAS_ADC_INFO(IN15, 0, 0, 0, 0, INVALID, INVALID, true),
+};
+
+/**
+ * struct palmas_gpadc - the palmas_gpadc structure
+ * @ch0_current:	channel 0 current source setting
+ *			0: 0 uA
+ *			1: 5 uA
+ *			2: 15 uA
+ *			3: 20 uA
+ * @ch3_current:	channel 0 current source setting
+ *			0: 0 uA
+ *			1: 10 uA
+ *			2: 400 uA
+ *			3: 800 uA
+ * @extended_delay:	enable the gpadc extended delay mode
+ * @auto_conversion_period:	define the auto_conversion_period
+ *
+ * This is the palmas_gpadc structure to store run-time information
+ * and pointers for this driver instance.
+ */
+
+struct palmas_gpadc {
+	struct device			*dev;
+	struct palmas			*palmas;
+	u8				ch0_current;
+	u8				ch3_current;
+	bool				extended_delay;
+	int				irq;
+	int				irq_auto_0;
+	int				irq_auto_1;
+	struct palmas_gpadc_info	*adc_info;
+	struct completion		conv_completion;
+	struct palmas_adc_wakeup_property wakeup1_data;
+	struct palmas_adc_wakeup_property wakeup2_data;
+	bool				wakeup1_enable;
+	bool				wakeup2_enable;
+	int				auto_conversion_period;
+};
+
+/*
+ * GPADC lock issue in AUTO mode.
+ * Impact: In AUTO mode, GPADC conversion can be locked after disabling AUTO
+ *	   mode feature.
+ * Details:
+ *	When the AUTO mode is the only conversion mode enabled, if the AUTO
+ *	mode feature is disabled with bit GPADC_AUTO_CTRL.  AUTO_CONV1_EN = 0
+ *	or bit GPADC_AUTO_CTRL.  AUTO_CONV0_EN = 0 during a conversion, the
+ *	conversion mechanism can be seen as locked meaning that all following
+ *	conversion will give 0 as a result.  Bit GPADC_STATUS.GPADC_AVAILABLE
+ *	will stay at 0 meaning that GPADC is busy.  An RT conversion can unlock
+ *	the GPADC.
+ *
+ * Workaround(s):
+ *	To avoid the lock mechanism, the workaround to follow before any stop
+ *	conversion request is:
+ *	Force the GPADC state machine to be ON by using the GPADC_CTRL1.
+ *		GPADC_FORCE bit = 1
+ *	Shutdown the GPADC AUTO conversion using
+ *		GPADC_AUTO_CTRL.SHUTDOWN_CONV[01] = 0.
+ *	After 100us, force the GPADC state machine to be OFF by using the
+ *		GPADC_CTRL1.  GPADC_FORCE bit = 0
+ */
+
+static int palmas_disable_auto_conversion(struct palmas_gpadc *adc)
+{
+	int ret;
+
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_CTRL1,
+			PALMAS_GPADC_CTRL1_GPADC_FORCE,
+			PALMAS_GPADC_CTRL1_GPADC_FORCE);
+	if (ret < 0) {
+		dev_err(adc->dev, "GPADC_CTRL1 update failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_AUTO_CTRL,
+			PALMAS_GPADC_AUTO_CTRL_SHUTDOWN_CONV1 |
+			PALMAS_GPADC_AUTO_CTRL_SHUTDOWN_CONV0,
+			0);
+	if (ret < 0) {
+		dev_err(adc->dev, "AUTO_CTRL update failed: %d\n", ret);
+		return ret;
+	}
+
+	udelay(100);
+
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_CTRL1,
+			PALMAS_GPADC_CTRL1_GPADC_FORCE, 0);
+	if (ret < 0)
+		dev_err(adc->dev, "GPADC_CTRL1 update failed: %d\n", ret);
+
+	return ret;
+}
+
+static irqreturn_t palmas_gpadc_irq(int irq, void *data)
+{
+	struct palmas_gpadc *adc = data;
+
+	complete(&adc->conv_completion);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t palmas_gpadc_irq_auto(int irq, void *data)
+{
+	struct palmas_gpadc *adc = data;
+
+	dev_dbg(adc->dev, "Threshold interrupt %d occurs\n", irq);
+	palmas_disable_auto_conversion(adc);
+
+	return IRQ_HANDLED;
+}
+
+static int palmas_gpadc_start_mask_interrupt(struct palmas_gpadc *adc,
+						bool mask)
+{
+	int ret;
+
+	if (!mask)
+		ret = palmas_update_bits(adc->palmas, PALMAS_INTERRUPT_BASE,
+					PALMAS_INT3_MASK,
+					PALMAS_INT3_MASK_GPADC_EOC_SW, 0);
+	else
+		ret = palmas_update_bits(adc->palmas, PALMAS_INTERRUPT_BASE,
+					PALMAS_INT3_MASK,
+					PALMAS_INT3_MASK_GPADC_EOC_SW,
+					PALMAS_INT3_MASK_GPADC_EOC_SW);
+	if (ret < 0)
+		dev_err(adc->dev, "GPADC INT MASK update failed: %d\n", ret);
+
+	return ret;
+}
+
+static int palmas_gpadc_enable(struct palmas_gpadc *adc, int adc_chan,
+			       int enable)
+{
+	unsigned int mask, val;
+	int ret;
+
+	if (enable) {
+		val = (adc->extended_delay
+			<< PALMAS_GPADC_RT_CTRL_EXTEND_DELAY_SHIFT);
+		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+					PALMAS_GPADC_RT_CTRL,
+					PALMAS_GPADC_RT_CTRL_EXTEND_DELAY, val);
+		if (ret < 0) {
+			dev_err(adc->dev, "RT_CTRL update failed: %d\n", ret);
+			return ret;
+		}
+
+		mask = (PALMAS_GPADC_CTRL1_CURRENT_SRC_CH0_MASK |
+			PALMAS_GPADC_CTRL1_CURRENT_SRC_CH3_MASK |
+			PALMAS_GPADC_CTRL1_GPADC_FORCE);
+		val = (adc->ch0_current
+			<< PALMAS_GPADC_CTRL1_CURRENT_SRC_CH0_SHIFT);
+		val |= (adc->ch3_current
+			<< PALMAS_GPADC_CTRL1_CURRENT_SRC_CH3_SHIFT);
+		val |= PALMAS_GPADC_CTRL1_GPADC_FORCE;
+		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_CTRL1, mask, val);
+		if (ret < 0) {
+			dev_err(adc->dev,
+				"Failed to update current setting: %d\n", ret);
+			return ret;
+		}
+
+		mask = (PALMAS_GPADC_SW_SELECT_SW_CONV0_SEL_MASK |
+			PALMAS_GPADC_SW_SELECT_SW_CONV_EN);
+		val = (adc_chan | PALMAS_GPADC_SW_SELECT_SW_CONV_EN);
+		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_SW_SELECT, mask, val);
+		if (ret < 0) {
+			dev_err(adc->dev, "SW_SELECT update failed: %d\n", ret);
+			return ret;
+		}
+	} else {
+		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_SW_SELECT, 0);
+		if (ret < 0)
+			dev_err(adc->dev, "SW_SELECT write failed: %d\n", ret);
+
+		ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_CTRL1,
+				PALMAS_GPADC_CTRL1_GPADC_FORCE, 0);
+		if (ret < 0) {
+			dev_err(adc->dev, "CTRL1 update failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
+static int palmas_gpadc_read_prepare(struct palmas_gpadc *adc, int adc_chan)
+{
+	int ret;
+
+	ret = palmas_gpadc_enable(adc, adc_chan, true);
+	if (ret < 0)
+		return ret;
+
+	return palmas_gpadc_start_mask_interrupt(adc, 0);
+}
+
+static void palmas_gpadc_read_done(struct palmas_gpadc *adc, int adc_chan)
+{
+	palmas_gpadc_start_mask_interrupt(adc, 1);
+	palmas_gpadc_enable(adc, adc_chan, false);
+}
+
+static int palmas_gpadc_calibrate(struct palmas_gpadc *adc, int adc_chan)
+{
+	int k;
+	int d1;
+	int d2;
+	int ret;
+	int gain;
+	int x1 =  adc->adc_info[adc_chan].x1;
+	int x2 =  adc->adc_info[adc_chan].x2;
+	int v1 = adc->adc_info[adc_chan].v1;
+	int v2 = adc->adc_info[adc_chan].v2;
+
+	ret = palmas_read(adc->palmas, PALMAS_TRIM_GPADC_BASE,
+				adc->adc_info[adc_chan].trim1_reg, &d1);
+	if (ret < 0) {
+		dev_err(adc->dev, "TRIM read failed: %d\n", ret);
+		goto scrub;
+	}
+
+	ret = palmas_read(adc->palmas, PALMAS_TRIM_GPADC_BASE,
+				adc->adc_info[adc_chan].trim2_reg, &d2);
+	if (ret < 0) {
+		dev_err(adc->dev, "TRIM read failed: %d\n", ret);
+		goto scrub;
+	}
+
+	/* gain error calculation */
+	k = (1000 + (1000 * (d2 - d1)) / (x2 - x1));
+
+	/* gain calculation */
+	gain = ((v2 - v1) * 1000) / (x2 - x1);
+
+	adc->adc_info[adc_chan].gain_error = k;
+	adc->adc_info[adc_chan].gain = gain;
+	/* offset Calculation */
+	adc->adc_info[adc_chan].offset = (d1 * 1000) - ((k - 1000) * x1);
+
+scrub:
+	return ret;
+}
+
+static int palmas_gpadc_start_conversion(struct palmas_gpadc *adc, int adc_chan)
+{
+	unsigned int val;
+	int ret;
+
+	init_completion(&adc->conv_completion);
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_SW_SELECT,
+				PALMAS_GPADC_SW_SELECT_SW_START_CONV0,
+				PALMAS_GPADC_SW_SELECT_SW_START_CONV0);
+	if (ret < 0) {
+		dev_err(adc->dev, "SELECT_SW_START write failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = wait_for_completion_timeout(&adc->conv_completion,
+				PALMAS_ADC_CONVERSION_TIMEOUT);
+	if (ret == 0) {
+		dev_err(adc->dev, "conversion not completed\n");
+		return -ETIMEDOUT;
+	}
+
+	ret = palmas_bulk_read(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_SW_CONV0_LSB, &val, 2);
+	if (ret < 0) {
+		dev_err(adc->dev, "SW_CONV0_LSB read failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = val & 0xFFF;
+
+	return ret;
+}
+
+static int palmas_gpadc_get_calibrated_code(struct palmas_gpadc *adc,
+						int adc_chan, int val)
+{
+	if (!adc->adc_info[adc_chan].is_uncalibrated)
+		val  = (val*1000 - adc->adc_info[adc_chan].offset) /
+					adc->adc_info[adc_chan].gain_error;
+
+	if (val < 0) {
+		dev_err(adc->dev, "Mismatch with calibration\n");
+		return 0;
+	}
+
+	val = (val * adc->adc_info[adc_chan].gain) / 1000;
+
+	return val;
+}
+
+static int palmas_gpadc_read_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
+{
+	struct  palmas_gpadc *adc = iio_priv(indio_dev);
+	int adc_chan = chan->channel;
+	int ret = 0;
+
+	if (adc_chan > PALMAS_ADC_CH_MAX)
+		return -EINVAL;
+
+	mutex_lock(&indio_dev->mlock);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = palmas_gpadc_read_prepare(adc, adc_chan);
+		if (ret < 0)
+			goto out;
+
+		ret = palmas_gpadc_start_conversion(adc, adc_chan);
+		if (ret < 0) {
+			dev_err(adc->dev,
+			"ADC start conversion failed\n");
+			goto out;
+		}
+
+		if (mask == IIO_CHAN_INFO_PROCESSED)
+			ret = palmas_gpadc_get_calibrated_code(
+							adc, adc_chan, ret);
+
+		*val = ret;
+
+		ret = IIO_VAL_INT;
+		goto out;
+	}
+
+	mutex_unlock(&indio_dev->mlock);
+	return ret;
+
+out:
+	palmas_gpadc_read_done(adc, adc_chan);
+	mutex_unlock(&indio_dev->mlock);
+
+	return ret;
+}
+
+static const struct iio_info palmas_gpadc_iio_info = {
+	.read_raw = palmas_gpadc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+#define PALMAS_ADC_CHAN_IIO(chan, _type, chan_info)	\
+{							\
+	.datasheet_name = PALMAS_DATASHEET_NAME(chan),	\
+	.type = _type,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
+			BIT(chan_info),			\
+	.indexed = 1,					\
+	.channel = PALMAS_ADC_CH_##chan,		\
+}
+
+static const struct iio_chan_spec palmas_gpadc_iio_channel[] = {
+	PALMAS_ADC_CHAN_IIO(IN0, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN1, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	PALMAS_ADC_CHAN_IIO(IN2, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN3, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	PALMAS_ADC_CHAN_IIO(IN4, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN5, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN6, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN7, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN8, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN9, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN10, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN11, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN12, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	PALMAS_ADC_CHAN_IIO(IN13, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	PALMAS_ADC_CHAN_IIO(IN14, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	PALMAS_ADC_CHAN_IIO(IN15, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+};
+
+static int palmas_gpadc_probe(struct platform_device *pdev)
+{
+	struct palmas_gpadc *adc;
+	struct palmas_platform_data *pdata;
+	struct palmas_gpadc_platform_data *gpadc_pdata = NULL;
+	struct iio_dev *indio_dev;
+	int ret, i;
+
+	pdata = dev_get_platdata(pdev->dev.parent);
+	if (!pdata || !pdata->gpadc_pdata) {
+		dev_err(&pdev->dev, "No platform data\n");
+		return -ENODEV;
+	}
+
+	gpadc_pdata = pdata->gpadc_pdata;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
+	if (!indio_dev) {
+		dev_err(&pdev->dev, "iio_device_alloc failed\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(indio_dev);
+	adc->dev = &pdev->dev;
+	adc->palmas = dev_get_drvdata(pdev->dev.parent);
+	adc->adc_info = palmas_gpadc_info;
+	init_completion(&adc->conv_completion);
+	dev_set_drvdata(&pdev->dev, indio_dev);
+
+	adc->auto_conversion_period = gpadc_pdata->auto_conversion_period_ms;
+	adc->irq = palmas_irq_get_virq(adc->palmas, PALMAS_GPADC_EOC_SW_IRQ);
+	if (adc->irq < 0) {
+		dev_err(adc->dev,
+			"get virq failed: %d\n", adc->irq);
+		ret = adc->irq;
+		goto out;
+	}
+	ret = request_threaded_irq(adc->irq, NULL,
+		palmas_gpadc_irq,
+		IRQF_ONESHOT | IRQF_EARLY_RESUME, dev_name(adc->dev),
+		adc);
+	if (ret < 0) {
+		dev_err(adc->dev,
+			"request irq %d failed: %d\n", adc->irq, ret);
+		goto out;
+	}
+
+	if (gpadc_pdata->adc_wakeup1_data) {
+		memcpy(&adc->wakeup1_data, gpadc_pdata->adc_wakeup1_data,
+			sizeof(adc->wakeup1_data));
+		adc->wakeup1_enable = true;
+		adc->irq_auto_0 =  platform_get_irq(pdev, 1);
+		ret = request_threaded_irq(adc->irq_auto_0, NULL,
+				palmas_gpadc_irq_auto,
+				IRQF_ONESHOT | IRQF_EARLY_RESUME,
+				"palmas-adc-auto-0", adc);
+		if (ret < 0) {
+			dev_err(adc->dev, "request auto0 irq %d failed: %d\n",
+				adc->irq_auto_0, ret);
+			goto out_irq_free;
+		}
+	}
+
+	if (gpadc_pdata->adc_wakeup2_data) {
+		memcpy(&adc->wakeup2_data, gpadc_pdata->adc_wakeup2_data,
+				sizeof(adc->wakeup2_data));
+		adc->wakeup2_enable = true;
+		adc->irq_auto_1 =  platform_get_irq(pdev, 2);
+		ret = request_threaded_irq(adc->irq_auto_1, NULL,
+				palmas_gpadc_irq_auto,
+				IRQF_ONESHOT | IRQF_EARLY_RESUME,
+				"palmas-adc-auto-1", adc);
+		if (ret < 0) {
+			dev_err(adc->dev, "request auto1 irq %d failed: %d\n",
+				adc->irq_auto_1, ret);
+			goto out_irq_auto0_free;
+		}
+	}
+
+	/* set the current source 0 (value 0/5/15/20 uA => 0..3) */
+	if (gpadc_pdata->ch0_current <= 1)
+		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_0;
+	else if (gpadc_pdata->ch0_current <= 5)
+		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_5;
+	else if (gpadc_pdata->ch0_current <= 15)
+		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_15;
+	else
+		adc->ch0_current = PALMAS_ADC_CH0_CURRENT_SRC_20;
+
+	/* set the current source 3 (value 0/10/400/800 uA => 0..3) */
+	if (gpadc_pdata->ch3_current <= 1)
+		adc->ch3_current = PALMAS_ADC_CH3_CURRENT_SRC_0;
+	else if (gpadc_pdata->ch3_current <= 10)
+		adc->ch3_current = PALMAS_ADC_CH3_CURRENT_SRC_10;
+	else if (gpadc_pdata->ch3_current <= 400)
+		adc->ch3_current = PALMAS_ADC_CH3_CURRENT_SRC_400;
+	else
+		adc->ch3_current = PALMAS_ADC_CH3_CURRENT_SRC_800;
+
+	adc->extended_delay = gpadc_pdata->extended_delay;
+
+	indio_dev->name = MOD_NAME;
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->info = &palmas_gpadc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = palmas_gpadc_iio_channel;
+	indio_dev->num_channels = ARRAY_SIZE(palmas_gpadc_iio_channel);
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(adc->dev, "iio_device_register() failed: %d\n", ret);
+		goto out_irq_auto1_free;
+	}
+
+	device_set_wakeup_capable(&pdev->dev, 1);
+	for (i = 0; i < PALMAS_ADC_CH_MAX; i++) {
+		if (!(adc->adc_info[i].is_uncalibrated))
+			palmas_gpadc_calibrate(adc, i);
+	}
+
+	if (adc->wakeup1_enable || adc->wakeup2_enable)
+		device_wakeup_enable(&pdev->dev);
+
+	return 0;
+
+out_irq_auto1_free:
+	if (gpadc_pdata->adc_wakeup2_data)
+		free_irq(adc->irq_auto_1, adc);
+out_irq_auto0_free:
+	if (gpadc_pdata->adc_wakeup1_data)
+		free_irq(adc->irq_auto_0, adc);
+out_irq_free:
+	free_irq(adc->irq, adc);
+out:
+	return ret;
+}
+
+static int palmas_gpadc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(&pdev->dev);
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+
+	if (adc->wakeup1_enable || adc->wakeup2_enable)
+		device_wakeup_disable(&pdev->dev);
+	iio_device_unregister(indio_dev);
+	free_irq(adc->irq, adc);
+	if (adc->wakeup1_enable)
+		free_irq(adc->irq_auto_0, adc);
+	if (adc->wakeup2_enable)
+		free_irq(adc->irq_auto_1, adc);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int palmas_adc_wakeup_configure(struct palmas_gpadc *adc)
+{
+	int adc_period, conv;
+	int i;
+	int ch0 = 0, ch1 = 0;
+	int thres;
+	int ret;
+
+	adc_period = adc->auto_conversion_period;
+	for (i = 0; i < 16; ++i) {
+		if (((1000 * (1 << i)) / 32) < adc_period)
+			continue;
+	}
+	if (i > 0)
+		i--;
+	adc_period = i;
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_AUTO_CTRL,
+			PALMAS_GPADC_AUTO_CTRL_COUNTER_CONV_MASK,
+			adc_period);
+	if (ret < 0) {
+		dev_err(adc->dev, "AUTO_CTRL write failed: %d\n", ret);
+		return ret;
+	}
+
+	conv = 0;
+	if (adc->wakeup1_enable) {
+		int polarity;
+
+		ch0 = adc->wakeup1_data.adc_channel_number;
+		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN;
+		if (adc->wakeup1_data.adc_high_threshold > 0) {
+			thres = adc->wakeup1_data.adc_high_threshold;
+			polarity = 0;
+		} else {
+			thres = adc->wakeup1_data.adc_low_threshold;
+			polarity = PALMAS_GPADC_THRES_CONV0_MSB_THRES_CONV0_POL;
+		}
+
+		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_THRES_CONV0_LSB, thres & 0xFF);
+		if (ret < 0) {
+			dev_err(adc->dev,
+				"THRES_CONV0_LSB write failed: %d\n", ret);
+			return ret;
+		}
+
+		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_THRES_CONV0_MSB,
+				((thres >> 8) & 0xF) | polarity);
+		if (ret < 0) {
+			dev_err(adc->dev,
+				"THRES_CONV0_MSB write failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	if (adc->wakeup2_enable) {
+		int polarity;
+
+		ch1 = adc->wakeup2_data.adc_channel_number;
+		conv |= PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN;
+		if (adc->wakeup2_data.adc_high_threshold > 0) {
+			thres = adc->wakeup2_data.adc_high_threshold;
+			polarity = 0;
+		} else {
+			thres = adc->wakeup2_data.adc_low_threshold;
+			polarity = PALMAS_GPADC_THRES_CONV1_MSB_THRES_CONV1_POL;
+		}
+
+		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_THRES_CONV1_LSB, thres & 0xFF);
+		if (ret < 0) {
+			dev_err(adc->dev,
+				"THRES_CONV1_LSB write failed: %d\n", ret);
+			return ret;
+		}
+
+		ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+				PALMAS_GPADC_THRES_CONV1_MSB,
+				((thres >> 8) & 0xF) | polarity);
+		if (ret < 0) {
+			dev_err(adc->dev,
+				"THRES_CONV1_MSB write failed: %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_AUTO_SELECT, (ch1 << 4) | ch0);
+	if (ret < 0) {
+		dev_err(adc->dev, "AUTO_SELECT write failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = palmas_update_bits(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_AUTO_CTRL,
+			PALMAS_GPADC_AUTO_CTRL_AUTO_CONV1_EN |
+			PALMAS_GPADC_AUTO_CTRL_AUTO_CONV0_EN, conv);
+	if (ret < 0)
+		dev_err(adc->dev, "AUTO_CTRL write failed: %d\n", ret);
+
+	return ret;
+}
+
+static int palmas_adc_wakeup_reset(struct palmas_gpadc *adc)
+{
+	int ret;
+
+	ret = palmas_write(adc->palmas, PALMAS_GPADC_BASE,
+			PALMAS_GPADC_AUTO_SELECT, 0);
+	if (ret < 0) {
+		dev_err(adc->dev, "AUTO_SELECT write failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = palmas_disable_auto_conversion(adc);
+	if (ret < 0)
+		dev_err(adc->dev, "Disable auto conversion failed: %d\n", ret);
+
+	return ret;
+}
+
+static int palmas_gpadc_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int wakeup = adc->wakeup1_enable || adc->wakeup2_enable;
+	int ret;
+
+	if (!device_may_wakeup(dev) || !wakeup)
+		return 0;
+
+	ret = palmas_adc_wakeup_configure(adc);
+	if (ret < 0)
+		return ret;
+
+	if (adc->wakeup1_enable)
+		enable_irq_wake(adc->irq_auto_0);
+
+	if (adc->wakeup2_enable)
+		enable_irq_wake(adc->irq_auto_1);
+
+	return 0;
+}
+
+static int palmas_gpadc_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct palmas_gpadc *adc = iio_priv(indio_dev);
+	int wakeup = adc->wakeup1_enable || adc->wakeup2_enable;
+	int ret;
+
+	if (!device_may_wakeup(dev) || !wakeup)
+		return 0;
+
+	ret = palmas_adc_wakeup_reset(adc);
+	if (ret < 0)
+		return ret;
+
+	if (adc->wakeup1_enable)
+		disable_irq_wake(adc->irq_auto_0);
+
+	if (adc->wakeup2_enable)
+		disable_irq_wake(adc->irq_auto_1);
+
+	return 0;
+};
+#endif
+
+static const struct dev_pm_ops palmas_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(palmas_gpadc_suspend,
+				palmas_gpadc_resume)
+};
+
+static struct platform_driver palmas_gpadc_driver = {
+	.probe = palmas_gpadc_probe,
+	.remove = palmas_gpadc_remove,
+	.driver = {
+		.name = MOD_NAME,
+		.pm = &palmas_pm_ops,
+	},
+};
+
+static int __init palmas_gpadc_init(void)
+{
+	return platform_driver_register(&palmas_gpadc_driver);
+}
+module_init(palmas_gpadc_init);
+
+static void __exit palmas_gpadc_exit(void)
+{
+	platform_driver_unregister(&palmas_gpadc_driver);
+}
+module_exit(palmas_gpadc_exit);
+
+MODULE_DESCRIPTION("palmas GPADC driver");
+MODULE_AUTHOR("Pradeep Goudagunta<pgoudagunta@nvidia.com>");
+MODULE_ALIAS("platform:palmas-gpadc");
+MODULE_LICENSE("GPL v2");