[Feature]add MT2731_MP2_MR2_SVN388 baseline version

Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/iio/adc/twl6030-gpadc.c b/src/kernel/linux/v4.14/drivers/iio/adc/twl6030-gpadc.c
new file mode 100644
index 0000000..bc0e60b
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/iio/adc/twl6030-gpadc.c
@@ -0,0 +1,1010 @@
+/*
+ * TWL6030 GPADC module driver
+ *
+ * Copyright (C) 2009-2013 Texas Instruments Inc.
+ * Nishant Kamat <nskamat@ti.com>
+ * Balaji T K <balajitk@ti.com>
+ * Graeme Gregory <gg@slimlogic.co.uk>
+ * Girish S Ghongdemath <girishsg@ti.com>
+ * Ambresh K <ambresh@ti.com>
+ * Oleksandr Kozaruk <oleksandr.kozaruk@ti.com
+ *
+ * Based on twl4030-madc.c
+ * Copyright (C) 2008 Nokia Corporation
+ * Mikko Ylinen <mikko.k.ylinen@nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/mfd/twl.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define DRIVER_NAME		"twl6030_gpadc"
+
+/*
+ * twl6030 per TRM has 17 channels, and twl6032 has 19 channels
+ * 2 test network channels are not used,
+ * 2 die temperature channels are not used either, as it is not
+ * defined how to convert ADC value to temperature
+ */
+#define TWL6030_GPADC_USED_CHANNELS		13
+#define TWL6030_GPADC_MAX_CHANNELS		15
+#define TWL6032_GPADC_USED_CHANNELS		15
+#define TWL6032_GPADC_MAX_CHANNELS		19
+#define TWL6030_GPADC_NUM_TRIM_REGS		16
+
+#define TWL6030_GPADC_CTRL_P1			0x05
+
+#define TWL6032_GPADC_GPSELECT_ISB		0x07
+#define TWL6032_GPADC_CTRL_P1			0x08
+
+#define TWL6032_GPADC_GPCH0_LSB			0x0d
+#define TWL6032_GPADC_GPCH0_MSB			0x0e
+
+#define TWL6030_GPADC_CTRL_P1_SP1		BIT(3)
+
+#define TWL6030_GPADC_GPCH0_LSB			(0x29)
+
+#define TWL6030_GPADC_RT_SW1_EOC_MASK		BIT(5)
+
+#define TWL6030_GPADC_TRIM1			0xCD
+
+#define TWL6030_REG_TOGGLE1			0x90
+#define TWL6030_GPADCS				BIT(1)
+#define TWL6030_GPADCR				BIT(0)
+
+/**
+ * struct twl6030_chnl_calib - channel calibration
+ * @gain:		slope coefficient for ideal curve
+ * @gain_error:		gain error
+ * @offset_error:	offset of the real curve
+ */
+struct twl6030_chnl_calib {
+	s32 gain;
+	s32 gain_error;
+	s32 offset_error;
+};
+
+/**
+ * struct twl6030_ideal_code - GPADC calibration parameters
+ * GPADC is calibrated in two points: close to the beginning and
+ * to the and of the measurable input range
+ *
+ * @channel:	channel number
+ * @code1:	ideal code for the input at the beginning
+ * @code2:	ideal code for at the end of the range
+ * @volt1:	voltage input at the beginning(low voltage)
+ * @volt2:	voltage input at the end(high voltage)
+ */
+struct twl6030_ideal_code {
+	int channel;
+	u16 code1;
+	u16 code2;
+	u16 volt1;
+	u16 volt2;
+};
+
+struct twl6030_gpadc_data;
+
+/**
+ * struct twl6030_gpadc_platform_data - platform specific data
+ * @nchannels:		number of GPADC channels
+ * @iio_channels:	iio channels
+ * @twl6030_ideal:	pointer to calibration parameters
+ * @start_conversion:	pointer to ADC start conversion function
+ * @channel_to_reg	pointer to ADC function to convert channel to
+ *			register address for reading conversion result
+ * @calibrate:		pointer to calibration function
+ */
+struct twl6030_gpadc_platform_data {
+	const int nchannels;
+	const struct iio_chan_spec *iio_channels;
+	const struct twl6030_ideal_code *ideal;
+	int (*start_conversion)(int channel);
+	u8 (*channel_to_reg)(int channel);
+	int (*calibrate)(struct twl6030_gpadc_data *gpadc);
+};
+
+/**
+ * struct twl6030_gpadc_data - GPADC data
+ * @dev:		device pointer
+ * @lock:		mutual exclusion lock for the structure
+ * @irq_complete:	completion to signal end of conversion
+ * @twl6030_cal_tbl:	pointer to calibration data for each
+ *			channel with gain error and offset
+ * @pdata:		pointer to device specific data
+ */
+struct twl6030_gpadc_data {
+	struct device	*dev;
+	struct mutex	lock;
+	struct completion	irq_complete;
+	struct twl6030_chnl_calib	*twl6030_cal_tbl;
+	const struct twl6030_gpadc_platform_data *pdata;
+};
+
+/*
+ * channels 11, 12, 13, 15 and 16 have no calibration data
+ * calibration offset is same for channels 1, 3, 4, 5
+ *
+ * The data is taken from GPADC_TRIM registers description.
+ * GPADC_TRIM registers keep difference between the code measured
+ * at volt1 and volt2 input voltages and corresponding code1 and code2
+ */
+static const struct twl6030_ideal_code
+	twl6030_ideal[TWL6030_GPADC_USED_CHANNELS] = {
+	[0] = { /* ch 0, external, battery type, resistor value */
+		.channel = 0,
+		.code1 = 116,
+		.code2 = 745,
+		.volt1 = 141,
+		.volt2 = 910,
+	},
+	[1] = { /* ch 1, external, battery temperature, NTC resistor value */
+		.channel = 1,
+		.code1 = 82,
+		.code2 = 900,
+		.volt1 = 100,
+		.volt2 = 1100,
+	},
+	[2] = { /* ch 2, external, audio accessory/general purpose */
+		.channel = 2,
+		.code1 = 55,
+		.code2 = 818,
+		.volt1 = 101,
+		.volt2 = 1499,
+	},
+	[3] = { /* ch 3, external, general purpose */
+		.channel = 3,
+		.code1 = 82,
+		.code2 = 900,
+		.volt1 = 100,
+		.volt2 = 1100,
+	},
+	[4] = { /* ch 4, external, temperature measurement/general purpose */
+		.channel = 4,
+		.code1 = 82,
+		.code2 = 900,
+		.volt1 = 100,
+		.volt2 = 1100,
+	},
+	[5] = { /* ch 5, external, general purpose */
+		.channel = 5,
+		.code1 = 82,
+		.code2 = 900,
+		.volt1 = 100,
+		.volt2 = 1100,
+	},
+	[6] = { /* ch 6, external, general purpose */
+		.channel = 6,
+		.code1 = 82,
+		.code2 = 900,
+		.volt1 = 100,
+		.volt2 = 1100,
+	},
+	[7] = { /* ch 7, internal, main battery */
+		.channel = 7,
+		.code1 = 614,
+		.code2 = 941,
+		.volt1 = 3001,
+		.volt2 = 4599,
+	},
+	[8] = { /* ch 8, internal, backup battery */
+		.channel = 8,
+		.code1 = 82,
+		.code2 = 688,
+		.volt1 = 501,
+		.volt2 = 4203,
+	},
+	[9] = { /* ch 9, internal, external charger input */
+		.channel = 9,
+		.code1 = 182,
+		.code2 = 818,
+		.volt1 = 2001,
+		.volt2 = 8996,
+	},
+	[10] = { /* ch 10, internal, VBUS */
+		.channel = 10,
+		.code1 = 149,
+		.code2 = 818,
+		.volt1 = 1001,
+		.volt2 = 5497,
+	},
+	[11] = { /* ch 11, internal, VBUS charging current */
+		.channel = 11,
+	},
+		/* ch 12, internal, Die temperature */
+		/* ch 13, internal, Die temperature */
+	[12] = { /* ch 14, internal, USB ID line */
+		.channel = 14,
+		.code1 = 48,
+		.code2 = 714,
+		.volt1 = 323,
+		.volt2 = 4800,
+	},
+};
+
+static const struct twl6030_ideal_code
+			twl6032_ideal[TWL6032_GPADC_USED_CHANNELS] = {
+	[0] = { /* ch 0, external, battery type, resistor value */
+		.channel = 0,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[1] = { /* ch 1, external, battery temperature, NTC resistor value */
+		.channel = 1,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[2] = { /* ch 2, external, audio accessory/general purpose */
+		.channel = 2,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 660,
+		.volt2 = 1500,
+	},
+	[3] = { /* ch 3, external, temperature with external diode/general
+								purpose */
+		.channel = 3,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[4] = { /* ch 4, external, temperature measurement/general purpose */
+		.channel = 4,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[5] = { /* ch 5, external, general purpose */
+		.channel = 5,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[6] = { /* ch 6, external, general purpose */
+		.channel = 6,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 440,
+		.volt2 = 1000,
+	},
+	[7] = { /* ch7, internal, system supply */
+		.channel = 7,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 2200,
+		.volt2 = 5000,
+	},
+	[8] = { /* ch8, internal, backup battery */
+		.channel = 8,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 2200,
+		.volt2 = 5000,
+	},
+	[9] = { /* ch 9, internal, external charger input */
+		.channel = 9,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 3960,
+		.volt2 = 9000,
+	},
+	[10] = { /* ch10, internal, VBUS */
+		.channel = 10,
+		.code1 = 150,
+		.code2 = 751,
+		.volt1 = 1000,
+		.volt2 = 5000,
+	},
+	[11] = { /* ch 11, internal, VBUS DC-DC output current */
+		.channel = 11,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 660,
+		.volt2 = 1500,
+	},
+		/* ch 12, internal, Die temperature */
+		/* ch 13, internal, Die temperature */
+	[12] = { /* ch 14, internal, USB ID line */
+		.channel = 14,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 2420,
+		.volt2 = 5500,
+	},
+		/* ch 15, internal, test network */
+		/* ch 16, internal, test network */
+	[13] = { /* ch 17, internal, battery charging current */
+		.channel = 17,
+	},
+	[14] = { /* ch 18, internal, battery voltage */
+		.channel = 18,
+		.code1 = 1441,
+		.code2 = 3276,
+		.volt1 = 2200,
+		.volt2 = 5000,
+	},
+};
+
+static inline int twl6030_gpadc_write(u8 reg, u8 val)
+{
+	return twl_i2c_write_u8(TWL6030_MODULE_GPADC, val, reg);
+}
+
+static inline int twl6030_gpadc_read(u8 reg, u8 *val)
+{
+
+	return twl_i2c_read(TWL6030_MODULE_GPADC, val, reg, 2);
+}
+
+static int twl6030_gpadc_enable_irq(u8 mask)
+{
+	int ret;
+
+	ret = twl6030_interrupt_unmask(mask, REG_INT_MSK_LINE_B);
+	if (ret < 0)
+		return ret;
+
+	ret = twl6030_interrupt_unmask(mask, REG_INT_MSK_STS_B);
+
+	return ret;
+}
+
+static void twl6030_gpadc_disable_irq(u8 mask)
+{
+	twl6030_interrupt_mask(mask, REG_INT_MSK_LINE_B);
+	twl6030_interrupt_mask(mask, REG_INT_MSK_STS_B);
+}
+
+static irqreturn_t twl6030_gpadc_irq_handler(int irq, void *indio_dev)
+{
+	struct twl6030_gpadc_data *gpadc = iio_priv(indio_dev);
+
+	complete(&gpadc->irq_complete);
+
+	return IRQ_HANDLED;
+}
+
+static int twl6030_start_conversion(int channel)
+{
+	return twl6030_gpadc_write(TWL6030_GPADC_CTRL_P1,
+					TWL6030_GPADC_CTRL_P1_SP1);
+}
+
+static int twl6032_start_conversion(int channel)
+{
+	int ret;
+
+	ret = twl6030_gpadc_write(TWL6032_GPADC_GPSELECT_ISB, channel);
+	if (ret)
+		return ret;
+
+	return twl6030_gpadc_write(TWL6032_GPADC_CTRL_P1,
+						TWL6030_GPADC_CTRL_P1_SP1);
+}
+
+static u8 twl6030_channel_to_reg(int channel)
+{
+	return TWL6030_GPADC_GPCH0_LSB + 2 * channel;
+}
+
+static u8 twl6032_channel_to_reg(int channel)
+{
+	/*
+	 * for any prior chosen channel, when the conversion is ready
+	 * the result is avalable in GPCH0_LSB, GPCH0_MSB.
+	 */
+
+	return TWL6032_GPADC_GPCH0_LSB;
+}
+
+static int twl6030_gpadc_lookup(const struct twl6030_ideal_code *ideal,
+		int channel, int size)
+{
+	int i;
+
+	for (i = 0; i < size; i++)
+		if (ideal[i].channel == channel)
+			break;
+
+	return i;
+}
+
+static int twl6030_channel_calibrated(const struct twl6030_gpadc_platform_data
+		*pdata, int channel)
+{
+	const struct twl6030_ideal_code *ideal = pdata->ideal;
+	int i;
+
+	i = twl6030_gpadc_lookup(ideal, channel, pdata->nchannels);
+	/* not calibrated channels have 0 in all structure members */
+	return pdata->ideal[i].code2;
+}
+
+static int twl6030_gpadc_make_correction(struct twl6030_gpadc_data *gpadc,
+		int channel, int raw_code)
+{
+	const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
+	int corrected_code;
+	int i;
+
+	i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);
+	corrected_code = ((raw_code * 1000) -
+		gpadc->twl6030_cal_tbl[i].offset_error) /
+		gpadc->twl6030_cal_tbl[i].gain_error;
+
+	return corrected_code;
+}
+
+static int twl6030_gpadc_get_raw(struct twl6030_gpadc_data *gpadc,
+		int channel, int *res)
+{
+	u8 reg = gpadc->pdata->channel_to_reg(channel);
+	__le16 val;
+	int raw_code;
+	int ret;
+
+	ret = twl6030_gpadc_read(reg, (u8 *)&val);
+	if (ret) {
+		dev_dbg(gpadc->dev, "unable to read register 0x%X\n", reg);
+		return ret;
+	}
+
+	raw_code = le16_to_cpu(val);
+	dev_dbg(gpadc->dev, "GPADC raw code: %d", raw_code);
+
+	if (twl6030_channel_calibrated(gpadc->pdata, channel))
+		*res = twl6030_gpadc_make_correction(gpadc, channel, raw_code);
+	else
+		*res = raw_code;
+
+	return ret;
+}
+
+static int twl6030_gpadc_get_processed(struct twl6030_gpadc_data *gpadc,
+		int channel, int *val)
+{
+	const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
+	int corrected_code;
+	int channel_value;
+	int i;
+	int ret;
+
+	ret = twl6030_gpadc_get_raw(gpadc, channel, &corrected_code);
+	if (ret)
+		return ret;
+
+	i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);
+	channel_value = corrected_code *
+			gpadc->twl6030_cal_tbl[i].gain;
+
+	/* Shift back into mV range */
+	channel_value /= 1000;
+
+	dev_dbg(gpadc->dev, "GPADC corrected code: %d", corrected_code);
+	dev_dbg(gpadc->dev, "GPADC value: %d", channel_value);
+
+	*val = channel_value;
+
+	return ret;
+}
+
+static int twl6030_gpadc_read_raw(struct iio_dev *indio_dev,
+			     const struct iio_chan_spec *chan,
+			     int *val, int *val2, long mask)
+{
+	struct twl6030_gpadc_data *gpadc = iio_priv(indio_dev);
+	int ret;
+	long timeout;
+
+	mutex_lock(&gpadc->lock);
+
+	ret = gpadc->pdata->start_conversion(chan->channel);
+	if (ret) {
+		dev_err(gpadc->dev, "failed to start conversion\n");
+		goto err;
+	}
+	/* wait for conversion to complete */
+	timeout = wait_for_completion_interruptible_timeout(
+				&gpadc->irq_complete, msecs_to_jiffies(5000));
+	if (timeout == 0) {
+		ret = -ETIMEDOUT;
+		goto err;
+	} else if (timeout < 0) {
+		ret = -EINTR;
+		goto err;
+	}
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = twl6030_gpadc_get_raw(gpadc, chan->channel, val);
+		ret = ret ? -EIO : IIO_VAL_INT;
+		break;
+
+	case IIO_CHAN_INFO_PROCESSED:
+		ret = twl6030_gpadc_get_processed(gpadc, chan->channel, val);
+		ret = ret ? -EIO : IIO_VAL_INT;
+		break;
+
+	default:
+		break;
+	}
+err:
+	mutex_unlock(&gpadc->lock);
+
+	return ret;
+}
+
+/*
+ * The GPADC channels are calibrated using a two point calibration method.
+ * The channels measured with two known values: volt1 and volt2, and
+ * ideal corresponding output codes are known: code1, code2.
+ * The difference(d1, d2) between ideal and measured codes stored in trim
+ * registers.
+ * The goal is to find offset and gain of the real curve for each calibrated
+ * channel.
+ * gain: k = 1 + ((d2 - d1) / (x2 - x1))
+ * offset: b = d1 + (k - 1) * x1
+ */
+static void twl6030_calibrate_channel(struct twl6030_gpadc_data *gpadc,
+		int channel, int d1, int d2)
+{
+	int b, k, gain, x1, x2, i;
+	const struct twl6030_ideal_code *ideal = gpadc->pdata->ideal;
+
+	i = twl6030_gpadc_lookup(ideal, channel, gpadc->pdata->nchannels);
+
+	/* Gain */
+	gain = ((ideal[i].volt2 - ideal[i].volt1) * 1000) /
+		(ideal[i].code2 - ideal[i].code1);
+
+	x1 = ideal[i].code1;
+	x2 = ideal[i].code2;
+
+	/* k - real curve gain */
+	k = 1000 + (((d2 - d1) * 1000) / (x2 - x1));
+
+	/* b - offset of the real curve gain */
+	b = (d1 * 1000) - (k - 1000) * x1;
+
+	gpadc->twl6030_cal_tbl[i].gain = gain;
+	gpadc->twl6030_cal_tbl[i].gain_error = k;
+	gpadc->twl6030_cal_tbl[i].offset_error = b;
+
+	dev_dbg(gpadc->dev, "GPADC d1   for Chn: %d = %d\n", channel, d1);
+	dev_dbg(gpadc->dev, "GPADC d2   for Chn: %d = %d\n", channel, d2);
+	dev_dbg(gpadc->dev, "GPADC x1   for Chn: %d = %d\n", channel, x1);
+	dev_dbg(gpadc->dev, "GPADC x2   for Chn: %d = %d\n", channel, x2);
+	dev_dbg(gpadc->dev, "GPADC Gain for Chn: %d = %d\n", channel, gain);
+	dev_dbg(gpadc->dev, "GPADC k    for Chn: %d = %d\n", channel, k);
+	dev_dbg(gpadc->dev, "GPADC b    for Chn: %d = %d\n", channel, b);
+}
+
+static inline int twl6030_gpadc_get_trim_offset(s8 d)
+{
+	/*
+	 * XXX NOTE!
+	 * bit 0 - sign, bit 7 - reserved, 6..1 - trim value
+	 * though, the documentation states that trim value
+	 * is absolute value, the correct conversion results are
+	 * obtained if the value is interpreted as 2's complement.
+	 */
+	__u32 temp = ((d & 0x7f) >> 1) | ((d & 1) << 6);
+
+	return sign_extend32(temp, 6);
+}
+
+static int twl6030_calibration(struct twl6030_gpadc_data *gpadc)
+{
+	int ret;
+	int chn;
+	u8 trim_regs[TWL6030_GPADC_NUM_TRIM_REGS];
+	s8 d1, d2;
+
+	/*
+	 * for calibration two measurements have been performed at
+	 * factory, for some channels, during the production test and
+	 * have been stored in registers. This two stored values are
+	 * used to correct the measurements. The values represent
+	 * offsets for the given input from the output on ideal curve.
+	 */
+	ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs,
+			TWL6030_GPADC_TRIM1, TWL6030_GPADC_NUM_TRIM_REGS);
+	if (ret < 0) {
+		dev_err(gpadc->dev, "calibration failed\n");
+		return ret;
+	}
+
+	for (chn = 0; chn < TWL6030_GPADC_MAX_CHANNELS; chn++) {
+
+		switch (chn) {
+		case 0:
+			d1 = trim_regs[0];
+			d2 = trim_regs[1];
+			break;
+		case 1:
+		case 3:
+		case 4:
+		case 5:
+		case 6:
+			d1 = trim_regs[4];
+			d2 = trim_regs[5];
+			break;
+		case 2:
+			d1 = trim_regs[12];
+			d2 = trim_regs[13];
+			break;
+		case 7:
+			d1 = trim_regs[6];
+			d2 = trim_regs[7];
+			break;
+		case 8:
+			d1 = trim_regs[2];
+			d2 = trim_regs[3];
+			break;
+		case 9:
+			d1 = trim_regs[8];
+			d2 = trim_regs[9];
+			break;
+		case 10:
+			d1 = trim_regs[10];
+			d2 = trim_regs[11];
+			break;
+		case 14:
+			d1 = trim_regs[14];
+			d2 = trim_regs[15];
+			break;
+		default:
+			continue;
+		}
+
+		d1 = twl6030_gpadc_get_trim_offset(d1);
+		d2 = twl6030_gpadc_get_trim_offset(d2);
+
+		twl6030_calibrate_channel(gpadc, chn, d1, d2);
+	}
+
+	return 0;
+}
+
+static int twl6032_get_trim_value(u8 *trim_regs, unsigned int reg0,
+		unsigned int reg1, unsigned int mask0, unsigned int mask1,
+		unsigned int shift0)
+{
+	int val;
+
+	val = (trim_regs[reg0] & mask0) << shift0;
+	val |= (trim_regs[reg1] & mask1) >> 1;
+	if (trim_regs[reg1] & 0x01)
+		val = -val;
+
+	return val;
+}
+
+static int twl6032_calibration(struct twl6030_gpadc_data *gpadc)
+{
+	int chn, d1 = 0, d2 = 0, temp;
+	u8 trim_regs[TWL6030_GPADC_NUM_TRIM_REGS];
+	int ret;
+
+	ret = twl_i2c_read(TWL6030_MODULE_ID2, trim_regs,
+			TWL6030_GPADC_TRIM1, TWL6030_GPADC_NUM_TRIM_REGS);
+	if (ret < 0) {
+		dev_err(gpadc->dev, "calibration failed\n");
+		return ret;
+	}
+
+	/*
+	 * Loop to calculate the value needed for returning voltages from
+	 * GPADC not values.
+	 *
+	 * gain is calculated to 3 decimal places fixed point.
+	 */
+	for (chn = 0; chn < TWL6032_GPADC_MAX_CHANNELS; chn++) {
+
+		switch (chn) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+		case 5:
+		case 6:
+		case 11:
+		case 14:
+			d1 = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
+								0x06, 2);
+			d2 = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
+								0x06, 2);
+			break;
+		case 8:
+			temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
+								0x06, 2);
+			d1 = temp + twl6032_get_trim_value(trim_regs, 7, 6,
+								0x18, 0x1E, 1);
+
+			temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3F,
+								0x06, 2);
+			d2 = temp + twl6032_get_trim_value(trim_regs, 9, 7,
+								0x1F, 0x06, 2);
+			break;
+		case 9:
+			temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
+								0x06, 2);
+			d1 = temp + twl6032_get_trim_value(trim_regs, 13, 11,
+								0x18, 0x1E, 1);
+
+			temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
+								0x06, 2);
+			d2 = temp + twl6032_get_trim_value(trim_regs, 15, 13,
+								0x1F, 0x06, 1);
+			break;
+		case 10:
+			d1 = twl6032_get_trim_value(trim_regs, 10, 8, 0x0f,
+								0x0E, 3);
+			d2 = twl6032_get_trim_value(trim_regs, 14, 12, 0x0f,
+								0x0E, 3);
+			break;
+		case 7:
+		case 18:
+			temp = twl6032_get_trim_value(trim_regs, 2, 0, 0x1f,
+								0x06, 2);
+
+			d1 = (trim_regs[4] & 0x7E) >> 1;
+			if (trim_regs[4] & 0x01)
+				d1 = -d1;
+			d1 += temp;
+
+			temp = twl6032_get_trim_value(trim_regs, 3, 1, 0x3f,
+								0x06, 2);
+
+			d2 = (trim_regs[5] & 0xFE) >> 1;
+			if (trim_regs[5] & 0x01)
+				d2 = -d2;
+
+			d2 += temp;
+			break;
+		default:
+			/* No data for other channels */
+			continue;
+		}
+
+		twl6030_calibrate_channel(gpadc, chn, d1, d2);
+	}
+
+	return 0;
+}
+
+#define TWL6030_GPADC_CHAN(chn, _type, chan_info) {	\
+	.type = _type,					\
+	.channel = chn,					\
+	.info_mask_separate = BIT(chan_info),		\
+	.indexed = 1,					\
+}
+
+static const struct iio_chan_spec twl6030_gpadc_iio_channels[] = {
+	TWL6030_GPADC_CHAN(0, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(1, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(2, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(3, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(4, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(5, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(6, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(7, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(8, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(9, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(10, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(11, IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(14, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+};
+
+static const struct iio_chan_spec twl6032_gpadc_iio_channels[] = {
+	TWL6030_GPADC_CHAN(0, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(1, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(2, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(3, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(4, IIO_TEMP, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(5, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(6, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(7, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(8, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(9, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(10, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(11, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(14, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+	TWL6030_GPADC_CHAN(17, IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
+	TWL6030_GPADC_CHAN(18, IIO_VOLTAGE, IIO_CHAN_INFO_PROCESSED),
+};
+
+static const struct iio_info twl6030_gpadc_iio_info = {
+	.read_raw = &twl6030_gpadc_read_raw,
+	.driver_module = THIS_MODULE,
+};
+
+static const struct twl6030_gpadc_platform_data twl6030_pdata = {
+	.iio_channels = twl6030_gpadc_iio_channels,
+	.nchannels = TWL6030_GPADC_USED_CHANNELS,
+	.ideal = twl6030_ideal,
+	.start_conversion = twl6030_start_conversion,
+	.channel_to_reg = twl6030_channel_to_reg,
+	.calibrate = twl6030_calibration,
+};
+
+static const struct twl6030_gpadc_platform_data twl6032_pdata = {
+	.iio_channels = twl6032_gpadc_iio_channels,
+	.nchannels = TWL6032_GPADC_USED_CHANNELS,
+	.ideal = twl6032_ideal,
+	.start_conversion = twl6032_start_conversion,
+	.channel_to_reg = twl6032_channel_to_reg,
+	.calibrate = twl6032_calibration,
+};
+
+static const struct of_device_id of_twl6030_match_tbl[] = {
+	{
+		.compatible = "ti,twl6030-gpadc",
+		.data = &twl6030_pdata,
+	},
+	{
+		.compatible = "ti,twl6032-gpadc",
+		.data = &twl6032_pdata,
+	},
+	{ /* end */ }
+};
+MODULE_DEVICE_TABLE(of, of_twl6030_match_tbl);
+
+static int twl6030_gpadc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct twl6030_gpadc_data *gpadc;
+	const struct twl6030_gpadc_platform_data *pdata;
+	const struct of_device_id *match;
+	struct iio_dev *indio_dev;
+	int irq;
+	int ret;
+
+	match = of_match_device(of_twl6030_match_tbl, dev);
+	if (!match)
+		return -EINVAL;
+
+	pdata = match->data;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*gpadc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	gpadc = iio_priv(indio_dev);
+
+	gpadc->twl6030_cal_tbl = devm_kzalloc(dev,
+					sizeof(*gpadc->twl6030_cal_tbl) *
+					pdata->nchannels, GFP_KERNEL);
+	if (!gpadc->twl6030_cal_tbl)
+		return -ENOMEM;
+
+	gpadc->dev = dev;
+	gpadc->pdata = pdata;
+
+	platform_set_drvdata(pdev, indio_dev);
+	mutex_init(&gpadc->lock);
+	init_completion(&gpadc->irq_complete);
+
+	ret = pdata->calibrate(gpadc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to read calibration registers\n");
+		return ret;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "failed to get irq\n");
+		return irq;
+	}
+
+	ret = devm_request_threaded_irq(dev, irq, NULL,
+				twl6030_gpadc_irq_handler,
+				IRQF_ONESHOT, "twl6030_gpadc", indio_dev);
+
+	ret = twl6030_gpadc_enable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to enable GPADC interrupt\n");
+		return ret;
+	}
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
+					TWL6030_REG_TOGGLE1);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to enable GPADC module\n");
+		return ret;
+	}
+
+	indio_dev->name = DRIVER_NAME;
+	indio_dev->dev.parent = dev;
+	indio_dev->info = &twl6030_gpadc_iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = pdata->iio_channels;
+	indio_dev->num_channels = pdata->nchannels;
+
+	return iio_device_register(indio_dev);
+}
+
+static int twl6030_gpadc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+	twl6030_gpadc_disable_irq(TWL6030_GPADC_RT_SW1_EOC_MASK);
+	iio_device_unregister(indio_dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int twl6030_gpadc_suspend(struct device *pdev)
+{
+	int ret;
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCR,
+				TWL6030_REG_TOGGLE1);
+	if (ret)
+		dev_err(pdev, "error resetting GPADC (%d)!\n", ret);
+
+	return 0;
+};
+
+static int twl6030_gpadc_resume(struct device *pdev)
+{
+	int ret;
+
+	ret = twl_i2c_write_u8(TWL6030_MODULE_ID1, TWL6030_GPADCS,
+				TWL6030_REG_TOGGLE1);
+	if (ret)
+		dev_err(pdev, "error setting GPADC (%d)!\n", ret);
+
+	return 0;
+};
+#endif
+
+static SIMPLE_DEV_PM_OPS(twl6030_gpadc_pm_ops, twl6030_gpadc_suspend,
+					twl6030_gpadc_resume);
+
+static struct platform_driver twl6030_gpadc_driver = {
+	.probe		= twl6030_gpadc_probe,
+	.remove		= twl6030_gpadc_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.pm	= &twl6030_gpadc_pm_ops,
+		.of_match_table = of_twl6030_match_tbl,
+	},
+};
+
+module_platform_driver(twl6030_gpadc_driver);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("Balaji T K <balajitk@ti.com>");
+MODULE_AUTHOR("Graeme Gregory <gg@slimlogic.co.uk>");
+MODULE_AUTHOR("Oleksandr Kozaruk <oleksandr.kozaruk@ti.com");
+MODULE_DESCRIPTION("twl6030 ADC driver");
+MODULE_LICENSE("GPL");