/*
 * 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/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>
#include <linux/i2c/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 */ }
};

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,
		.owner	= THIS_MODULE,
		.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");