/*
 * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only 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.
 */

#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <linux/log2.h>
#include <linux/thermal.h>

#include <dt-bindings/iio/qcom,spmi-vadc.h>

/* VADC bit definitions */
#define VADC_REVISION2_SUPPORTED_VADC		1
#define VADC_PERPH_TYPE_ADC			8
#define VADC_PERPH_SUBTYPE_VADC			1
#define VADC_STATUS1_OP_MODE			4
#define VADC_STATUS1_REQ_STS			BIT(1)
#define VADC_STATUS1_EOC			BIT(0)
#define VADC_STATUS1_REQ_STS_EOC_MASK		0x3
#define VADC_OP_MODE_SHIFT			3
#define VADC_OP_MODE_NORMAL			0
#define VADC_AMUX_TRIM_EN			BIT(1)
#define VADC_ADC_TRIM_EN			BIT(0)
#define VADC_EN_CTL1_SET			BIT(7)
#define VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT	2
#define VADC_CONV_REQ_SET			BIT(7)
#define VADC_FAST_AVG_EN_SET			BIT(7)
#define VADC_FOLLOW_WARM_RB			BIT(2)
#define VADC_CONV_TIME_MIN_US			2000
#define VADC_CONV_TIME_MAX_US			2100

#define VADC_ABSOLUTE_RANGE_UV			625000
#define VADC_RATIOMETRIC_RANGE_UV		1800000

#define VADC_DEF_PRESCALING			0 /* 1:1 */
#define VADC_DEF_DECIMATION			0 /* 512 */
#define VADC_DEF_HW_SETTLE_TIME			0 /* 0 us */
#define VADC_DEF_AVG_SAMPLES			0 /* 1 sample */
#define VADC_DEF_CALIB_TYPE			VADC_CALIB_ABSOLUTE

#define VADC_DECIMATION_MIN			512
#define VADC_DECIMATION_MAX			4096

#define VADC_HW_SETTLE_DELAY_MAX		10000
#define VADC_AVG_SAMPLES_MAX			512

#define KELVINMIL_CELSIUSMIL			273150

#define PMP8074_DIE_TEMP_SLOPE_NUM		10
#define PMP8074_DIE_TEMP_SLOPE_DEN		171
#define PMP8074_DIE_TEMP_OFFSET			286

#define PMP8074_PA_THERM_SLOPE			2397
#define PMP8074_PA_THERM_BASE			506
#define PMP8074_PA_THERM_FACTOR			100


enum vadc_reg {
	VADC_REVISION2,
	VADC_PERPH_TYPE,
	VADC_PERPH_SUBTYPE,
	VADC_STATUS1,
	VADC_MODE_CTL,
	VADC_EN_CTL1,
	VADC_ADC_DIG_PARAM,
	VADC_FAST_AVG_CTL,
	VADC_FAST_AVG_EN,
	VADC_ADC_CH_SEL_CTL,
	VADC_HW_SETTLE_DELAY,
	VADC_CONV_REQ,
	VADC_DATA,
	VADC_ACCESS,
	VADC_ACCESS_DATA,
	VADC_PERH_RESET_CTL3,
	VADC_REG_MAX
};

static u32 reg_offset_default[] = {
	[VADC_REVISION2] = 0x1,
	[VADC_PERPH_TYPE] = 0x4,
	[VADC_PERPH_SUBTYPE] = 0x5,
	[VADC_STATUS1] = 0x8,
	[VADC_MODE_CTL] = 0x40,
	[VADC_EN_CTL1] = 0x46,
	[VADC_ADC_DIG_PARAM] = 0x50,
	[VADC_FAST_AVG_CTL] = 0x5a,
	[VADC_FAST_AVG_EN] = 0x5b,
	[VADC_ADC_CH_SEL_CTL] = 0x48,
	[VADC_HW_SETTLE_DELAY] = 0x51,
	[VADC_CONV_REQ] = 0x52,
	[VADC_DATA] = 0x60,
	[VADC_ACCESS] = 0xd0,
	[VADC_ACCESS_DATA] = 0xa5,
	[VADC_PERH_RESET_CTL3] = 0xda
};

static u32 reg_offset_pmp8074[] = {
	[VADC_REVISION2] = 0x1,
	[VADC_PERPH_TYPE] = 0x4,
	[VADC_PERPH_SUBTYPE] = 0x5,
	[VADC_STATUS1] = 0x8,
	[VADC_EN_CTL1] = 0x46,
	[VADC_ADC_DIG_PARAM] = 0x42,
	[VADC_FAST_AVG_CTL] = 0x43,
	[VADC_FAST_AVG_EN] = 0x43,
	[VADC_ADC_CH_SEL_CTL] = 0x44,
	[VADC_HW_SETTLE_DELAY] = 0x45,
	[VADC_CONV_REQ] = 0x47,
	[VADC_DATA] = 0x50,
	[VADC_ACCESS] = 0xd0,
	[VADC_ACCESS_DATA] = 0xa5,
	[VADC_PERH_RESET_CTL3] = 0xda
};

struct vadc_priv;

struct device_data {
	struct vadc_channels *vadc_chans;
	u32 *reg;
	bool mode_ctl;
	bool dynamic_calib;
	bool force_decimation;
	u16 ch_min;
	u16 ch_max;
	u32 decimation_mask;
	u32 adc_min;
	u32 adc_max;
	u32 uV_max;
	u32 (*adc_to_uV)(struct vadc_priv *, u16);
	int (*adc_to_degc)(struct vadc_priv *, u16);
	struct thermal_zone_device_ops *thermal_ops;
};

struct vadc_thermal_data {
	int thermal_chan;
	struct thermal_zone_device *tz_dev;
	struct vadc_priv *vadc_dev;
};

/*
 * VADC_CALIB_ABSOLUTE: uses the 625mV and 1.25V as reference channels.
 * VADC_CALIB_RATIOMETRIC: uses the reference voltage (1.8V) and GND for
 * calibration.
 */
enum vadc_calibration {
	VADC_CALIB_ABSOLUTE = 0,
	VADC_CALIB_RATIOMETRIC
};

/**
 * struct vadc_linear_graph - Represent ADC characteristics.
 * @dy: numerator slope to calculate the gain.
 * @dx: denominator slope to calculate the gain.
 * @gnd: A/D word of the ground reference used for the channel.
 *
 * Each ADC device has different offset and gain parameters which are
 * computed to calibrate the device.
 */
struct vadc_linear_graph {
	s32 dy;
	s32 dx;
	s32 gnd;
};

/**
 * struct vadc_prescale_ratio - Represent scaling ratio for ADC input.
 * @num: the inverse numerator of the gain applied to the input channel.
 * @den: the inverse denominator of the gain applied to the input channel.
 */
struct vadc_prescale_ratio {
	u32 num;
	u32 den;
};

/**
 * struct vadc_channel_prop - VADC channel property.
 * @channel: channel number, refer to the channel list.
 * @calibration: calibration type.
 * @decimation: sampling rate supported for the channel.
 * @prescale: channel scaling performed on the input signal.
 * @hw_settle_time: the time between AMUX being configured and the
 *	start of conversion.
 * @avg_samples: ability to provide single result from the ADC
 *	that is an average of multiple measurements.
 */
struct vadc_channel_prop {
	unsigned int channel;
	enum vadc_calibration calibration;
	unsigned int decimation;
	unsigned int prescale;
	unsigned int hw_settle_time;
	unsigned int avg_samples;
};

/**
 * struct vadc_priv - VADC private structure.
 * @regmap: pointer to struct regmap.
 * @dev: pointer to struct device.
 * @base: base address for the ADC peripheral.
 * @nchannels: number of VADC channels.
 * @chan_props: array of VADC channel properties.
 * @iio_chans: array of IIO channels specification.
 * @are_ref_measured: are reference points measured.
 * @poll_eoc: use polling instead of interrupt.
 * @complete: VADC result notification after interrupt is received.
 * @graph: store parameters for calibration.
 * @lock: ADC lock for access to the peripheral.
 */
struct vadc_priv {
	struct regmap		 *regmap;
	struct device		 *dev;
	u16			 base;
	unsigned int		 nchannels;
	struct vadc_channel_prop *chan_props;
	struct iio_chan_spec	 *iio_chans;
	bool			 are_ref_measured;
	bool			 poll_eoc;
	struct completion	 complete;
	struct vadc_linear_graph graph[2];
	struct mutex		 lock;
	struct device_data	 *dev_data;
	struct vadc_thermal_data *vadc_therm_chan;
};

static const struct vadc_prescale_ratio vadc_prescale_ratios[] = {
	{.num =  1, .den =  1},
	{.num =  1, .den =  3},
	{.num =  1, .den =  4},
	{.num =  1, .den =  6},
	{.num =  1, .den = 20},
	{.num =  1, .den =  8},
	{.num = 10, .den = 81},
	{.num =  1, .den = 10}
};

static int vadc_read(struct vadc_priv *vadc, enum vadc_reg reg, u8 *data)
{
	u32 reg_offset = vadc->dev_data->reg[reg];
	return regmap_bulk_read(vadc->regmap, vadc->base + reg_offset, data, 1);
}

static int vadc_write(struct vadc_priv *vadc, enum vadc_reg reg, u8 data)
{
	u32 reg_offset = vadc->dev_data->reg[reg];
	return regmap_write(vadc->regmap, vadc->base + reg_offset, data);
}

static int vadc_reset(struct vadc_priv *vadc)
{
	u8 data;
	int ret;

	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
	if (ret)
		return ret;

	ret = vadc_read(vadc, VADC_PERH_RESET_CTL3, &data);
	if (ret)
		return ret;

	ret = vadc_write(vadc, VADC_ACCESS, VADC_ACCESS_DATA);
	if (ret)
		return ret;

	data |= VADC_FOLLOW_WARM_RB;

	return vadc_write(vadc, VADC_PERH_RESET_CTL3, data);
}

static int vadc_set_state(struct vadc_priv *vadc, bool state)
{
	return vadc_write(vadc, VADC_EN_CTL1, state ? VADC_EN_CTL1_SET : 0);
}

static void vadc_show_status(struct vadc_priv *vadc)
{
	u8 mode = 0, sta1, chan, dig, en, req;
	int ret;

	if (vadc->dev_data->mode_ctl) {
		ret = vadc_read(vadc, VADC_MODE_CTL, &mode);
		if (ret)
			return;
	}

	ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &dig);
	if (ret)
		return;

	ret = vadc_read(vadc, VADC_ADC_CH_SEL_CTL, &chan);
	if (ret)
		return;

	ret = vadc_read(vadc, VADC_CONV_REQ, &req);
	if (ret)
		return;

	ret = vadc_read(vadc, VADC_STATUS1, &sta1);
	if (ret)
		return;

	ret = vadc_read(vadc, VADC_EN_CTL1, &en);
	if (ret)
		return;

	dev_err(vadc->dev,
		"mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n",
		mode, en, chan, dig, req, sta1);
}

static int vadc_configure(struct vadc_priv *vadc,
			  struct vadc_channel_prop *prop)
{
	u8 decimation, mode_ctrl, val;
	int ret;

	if (vadc->dev_data->mode_ctl) {
		/* Mode selection */
		mode_ctrl = (VADC_OP_MODE_NORMAL << VADC_OP_MODE_SHIFT) |
			     VADC_ADC_TRIM_EN | VADC_AMUX_TRIM_EN;
		ret = vadc_write(vadc, VADC_MODE_CTL, mode_ctrl);
		if (ret)
			return ret;
	}

	/* Channel selection */
	ret = vadc_write(vadc, VADC_ADC_CH_SEL_CTL, prop->channel);
	if (ret)
		return ret;

	/* Digital parameter setup */
	decimation = prop->decimation << VADC_ADC_DIG_DEC_RATIO_SEL_SHIFT;
	if (!vadc->dev_data->force_decimation) {
		ret = vadc_read(vadc, VADC_ADC_DIG_PARAM, &val);
		if (ret)
			return ret;
		val &= (~vadc->dev_data->decimation_mask);
		decimation |= val;
	}
	ret = vadc_write(vadc, VADC_ADC_DIG_PARAM, decimation);
	if (ret)
		return ret;

	/* HW settle time delay */
	ret = vadc_write(vadc, VADC_HW_SETTLE_DELAY, prop->hw_settle_time);
	if (ret)
		return ret;

	ret = vadc_write(vadc, VADC_FAST_AVG_CTL, prop->avg_samples);
	if (ret)
		return ret;

	if (prop->avg_samples)
		ret = vadc_write(vadc, VADC_FAST_AVG_EN, VADC_FAST_AVG_EN_SET);
	else
		ret = vadc_write(vadc, VADC_FAST_AVG_EN, 0);

	return ret;
}

static int vadc_poll_wait_eoc(struct vadc_priv *vadc, unsigned int interval_us)
{
	unsigned int count, retry;
	u8 sta1;
	int ret;

	retry = interval_us / VADC_CONV_TIME_MIN_US;

	for (count = 0; count < retry; count++) {
		ret = vadc_read(vadc, VADC_STATUS1, &sta1);
		if (ret)
			return ret;

		sta1 &= VADC_STATUS1_REQ_STS_EOC_MASK;
		if (sta1 == VADC_STATUS1_EOC)
			return 0;

		usleep_range(VADC_CONV_TIME_MIN_US, VADC_CONV_TIME_MAX_US);
	}

	vadc_show_status(vadc);

	return -ETIMEDOUT;
}

static int vadc_read_result(struct vadc_priv *vadc, u16 *data)
{
	int ret;

	ret = regmap_bulk_read(vadc->regmap, vadc->base
			+ vadc->dev_data->reg[VADC_DATA], data, 2);
	if (ret)
		return ret;

	*data = clamp_t(u16, *data,
			vadc->dev_data->adc_min, vadc->dev_data->adc_max);

	return 0;
}

/*
 * Convert ADC to voltage using the formula
 * voltage = (adc_code * max uV)/Max ADC
 *
 */
static u32 pmp8074_adc_to_uV(struct vadc_priv *vadc, u16 adc_code)
{
	u32 voltage, quot, reminder;

	pr_info("Raw ADC: %d\n", adc_code);

	quot = (adc_code * (vadc->dev_data->uV_max/1000))
				/vadc->dev_data->adc_max;
	reminder = (adc_code * (vadc->dev_data->uV_max/1000))
				%vadc->dev_data->adc_max;

	/* Convert into mV to uV without losing granuality */
	reminder = (reminder * 1000)/vadc->dev_data->adc_max;
	voltage = (quot * 1000) + reminder;

	return voltage;
}

/*
 * Convert ADC to temperature in deg.C
 * PMIC_CaseTemp(deg.C) = (10/171) * (RawADCval) - 286
 *
 */
static int pmp8074_adc_to_degc(struct vadc_priv *vadc, u16 adc_code)
{
	int degc;

	pr_info("Raw ADC: %d\n", adc_code);
	degc = ((PMP8074_DIE_TEMP_SLOPE_NUM * adc_code)
		/PMP8074_DIE_TEMP_SLOPE_DEN) - PMP8074_DIE_TEMP_OFFSET;

	return degc;
}

static struct vadc_channel_prop *vadc_get_channel(struct vadc_priv *vadc,
						  unsigned int num)
{
	unsigned int i;

	for (i = 0; i < vadc->nchannels; i++)
		if (vadc->chan_props[i].channel == num)
			return &vadc->chan_props[i];

	dev_dbg(vadc->dev, "no such channel %02x\n", num);

	return NULL;
}

static int vadc_do_conversion(struct vadc_priv *vadc,
			      struct vadc_channel_prop *prop, u16 *data)
{
	unsigned int timeout;
	int ret;

	mutex_lock(&vadc->lock);

	ret = vadc_configure(vadc, prop);
	if (ret)
		goto unlock;

	if (!vadc->poll_eoc)
		reinit_completion(&vadc->complete);

	ret = vadc_set_state(vadc, true);
	if (ret)
		goto unlock;

	ret = vadc_write(vadc, VADC_CONV_REQ, VADC_CONV_REQ_SET);
	if (ret)
		goto err_disable;

	timeout = BIT(prop->avg_samples) * VADC_CONV_TIME_MIN_US * 2;

	if (vadc->poll_eoc) {
		ret = vadc_poll_wait_eoc(vadc, timeout);
	} else {
		ret = wait_for_completion_timeout(&vadc->complete, timeout);
		if (!ret) {
			ret = -ETIMEDOUT;
			goto err_disable;
		}

		/* Double check conversion status */
		ret = vadc_poll_wait_eoc(vadc, VADC_CONV_TIME_MIN_US);
		if (ret)
			goto err_disable;
	}

	ret = vadc_read_result(vadc, data);

err_disable:
	vadc_set_state(vadc, false);
	if (ret)
		dev_err(vadc->dev, "conversion failed\n");
unlock:
	mutex_unlock(&vadc->lock);
	return ret;
}

static int vadc_measure_ref_points(struct vadc_priv *vadc)
{
	struct vadc_channel_prop *prop;
	u16 read_1, read_2;
	int ret;

	vadc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
	vadc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;

	prop = vadc_get_channel(vadc, VADC_REF_1250MV);
	if (!prop) {
		ret = -EINVAL;
		goto err;
	}
	ret = vadc_do_conversion(vadc, prop, &read_1);
	if (ret)
		goto err;

	/* Try with buffered 625mV channel first */
	prop = vadc_get_channel(vadc, VADC_SPARE1);
	if (!prop)
		prop = vadc_get_channel(vadc, VADC_REF_625MV);

	if (!prop) {
		ret = -EINVAL;
		goto err;
	}
	ret = vadc_do_conversion(vadc, prop, &read_2);
	if (ret)
		goto err;

	if (read_1 == read_2) {
		ret = -EINVAL;
		goto err;
	}

	vadc->graph[VADC_CALIB_ABSOLUTE].dy = read_1 - read_2;
	vadc->graph[VADC_CALIB_ABSOLUTE].gnd = read_2;

	/* Ratiometric calibration */
	prop = vadc_get_channel(vadc, VADC_VDD_VADC);
	if (!prop) {
		ret = -EINVAL;
		goto err;
	}
	ret = vadc_do_conversion(vadc, prop, &read_1);
	if (ret)
		goto err;

	prop = vadc_get_channel(vadc, VADC_GND_REF);
	if (!prop) {
		ret = -EINVAL;
		goto err;
	}
	ret = vadc_do_conversion(vadc, prop, &read_2);
	if (ret)
		goto err;

	if (read_1 == read_2) {
		ret = -EINVAL;
		goto err;
	}

	vadc->graph[VADC_CALIB_RATIOMETRIC].dy = read_1 - read_2;
	vadc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_2;
err:
	if (ret)
		dev_err(vadc->dev, "measure reference points failed\n");

	return ret;
}

static s32 vadc_calibrate(struct vadc_priv *vadc,
			  const struct vadc_channel_prop *prop, u16 adc_code)
{
	const struct vadc_prescale_ratio *prescale;
	s64 voltage;

	voltage = adc_code - vadc->graph[prop->calibration].gnd;
	voltage *= vadc->graph[prop->calibration].dx;
	voltage = div64_s64(voltage, vadc->graph[prop->calibration].dy);

	if (prop->calibration == VADC_CALIB_ABSOLUTE)
		voltage += vadc->graph[prop->calibration].dx;

	if (voltage < 0)
		voltage = 0;

	prescale = &vadc_prescale_ratios[prop->prescale];

	voltage = voltage * prescale->den;

	return div64_s64(voltage, prescale->num);
}

static int vadc_decimation_from_dt(u32 value)
{
	if (!is_power_of_2(value) || value < VADC_DECIMATION_MIN ||
	    value > VADC_DECIMATION_MAX)
		return -EINVAL;

	return __ffs64(value / VADC_DECIMATION_MIN);
}

static int vadc_prescaling_from_dt(u32 num, u32 den)
{
	unsigned int pre;

	for (pre = 0; pre < ARRAY_SIZE(vadc_prescale_ratios); pre++)
		if (vadc_prescale_ratios[pre].num == num &&
		    vadc_prescale_ratios[pre].den == den)
			break;

	if (pre == ARRAY_SIZE(vadc_prescale_ratios))
		return -EINVAL;

	return pre;
}

static int vadc_hw_settle_time_from_dt(u32 value)
{
	if ((value <= 1000 && value % 100) || (value > 1000 && value % 2000))
		return -EINVAL;

	if (value <= 1000)
		value /= 100;
	else
		value = value / 2000 + 10;

	return value;
}

static int vadc_avg_samples_from_dt(u32 value)
{
	if (!is_power_of_2(value) || value > VADC_AVG_SAMPLES_MAX)
		return -EINVAL;

	return __ffs64(value);
}

static int vadc_read_raw(struct iio_dev *indio_dev,
			 struct iio_chan_spec const *chan, int *val, int *val2,
			 long mask)
{
	struct vadc_priv *vadc = iio_priv(indio_dev);
	struct vadc_channel_prop *prop;
	u16 adc_code;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
		prop = &vadc->chan_props[chan->address];
		ret = vadc_do_conversion(vadc, prop, &adc_code);
		if (ret)
			break;

		if (!vadc->dev_data->dynamic_calib) {
			if (vadc->dev_data->adc_to_degc)
				*val = vadc->dev_data->adc_to_degc(vadc,
								adc_code);
			else
				return -EINVAL;
		}
		else {
			*val = vadc_calibrate(vadc, prop, adc_code);

			/* 2mV/K, return milli Celsius */
			*val /= 2;
			*val -= KELVINMIL_CELSIUSMIL;
		}

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_RAW:
		prop = &vadc->chan_props[chan->address];
		ret = vadc_do_conversion(vadc, prop, &adc_code);
		if (ret)
			break;

		if (!vadc->dev_data->dynamic_calib) {
			if (vadc->dev_data->adc_to_uV)
				*val = vadc->dev_data->adc_to_uV(vadc,
								adc_code);
			else
				return -EINVAL;
		} else
			*val = vadc_calibrate(vadc, prop, adc_code);

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	default:
		ret = -EINVAL;
		break;
	}

	return ret;
}

static int vadc_of_xlate(struct iio_dev *indio_dev,
			 const struct of_phandle_args *iiospec)
{
	struct vadc_priv *vadc = iio_priv(indio_dev);
	unsigned int i;

	for (i = 0; i < vadc->nchannels; i++)
		if (vadc->iio_chans[i].channel == iiospec->args[0])
			return i;

	return -EINVAL;
}

static const struct iio_info vadc_info = {
	.read_raw = vadc_read_raw,
	.of_xlate = vadc_of_xlate,
	.driver_module = THIS_MODULE,
};

struct vadc_channels {
	const char *datasheet_name;
	unsigned int prescale_index;
	enum iio_chan_type type;
	long info_mask;
};

#define VADC_CHAN(_dname, _type, _mask, _pre)				\
	[VADC_##_dname] = {						\
		.datasheet_name = __stringify(_dname),			\
		.prescale_index = _pre,					\
		.type = _type,						\
		.info_mask = _mask					\
	},								\

#define VADC_CHAN_TEMP(_dname, _pre)					\
	VADC_CHAN(_dname, IIO_TEMP, BIT(IIO_CHAN_INFO_PROCESSED), _pre)	\

#define VADC_CHAN_VOLT(_dname, _pre)					\
	VADC_CHAN(_dname, IIO_VOLTAGE,					\
		  BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),	\
		  _pre)							\

/*
 * The array represents all possible ADC channels found in the supported PMICs.
 * Every index in the array is equal to the channel number per datasheet. The
 * gaps in the array should be treated as reserved channels.
 */
static struct vadc_channels default_vadc_chans[] = {
	VADC_CHAN_VOLT(USBIN, 4)
	VADC_CHAN_VOLT(DCIN, 4)
	VADC_CHAN_VOLT(VCHG_SNS, 3)
	VADC_CHAN_VOLT(SPARE1_03, 1)
	VADC_CHAN_VOLT(USB_ID_MV, 1)
	VADC_CHAN_VOLT(VCOIN, 1)
	VADC_CHAN_VOLT(VBAT_SNS, 1)
	VADC_CHAN_VOLT(VSYS, 1)
	VADC_CHAN_TEMP(DIE_TEMP, 0)
	VADC_CHAN_VOLT(REF_625MV, 0)
	VADC_CHAN_VOLT(REF_1250MV, 0)
	VADC_CHAN_VOLT(CHG_TEMP, 0)
	VADC_CHAN_VOLT(SPARE1, 0)
	VADC_CHAN_VOLT(SPARE2, 0)
	VADC_CHAN_VOLT(GND_REF, 0)
	VADC_CHAN_VOLT(VDD_VADC, 0)

	VADC_CHAN_VOLT(P_MUX1_1_1, 0)
	VADC_CHAN_VOLT(P_MUX2_1_1, 0)
	VADC_CHAN_VOLT(P_MUX3_1_1, 0)
	VADC_CHAN_VOLT(P_MUX4_1_1, 0)
	VADC_CHAN_VOLT(P_MUX5_1_1, 0)
	VADC_CHAN_VOLT(P_MUX6_1_1, 0)
	VADC_CHAN_VOLT(P_MUX7_1_1, 0)
	VADC_CHAN_VOLT(P_MUX8_1_1, 0)
	VADC_CHAN_VOLT(P_MUX9_1_1, 0)
	VADC_CHAN_VOLT(P_MUX10_1_1, 0)
	VADC_CHAN_VOLT(P_MUX11_1_1, 0)
	VADC_CHAN_VOLT(P_MUX12_1_1, 0)
	VADC_CHAN_VOLT(P_MUX13_1_1, 0)
	VADC_CHAN_VOLT(P_MUX14_1_1, 0)
	VADC_CHAN_VOLT(P_MUX15_1_1, 0)
	VADC_CHAN_VOLT(P_MUX16_1_1, 0)

	VADC_CHAN_VOLT(P_MUX1_1_3, 1)
	VADC_CHAN_VOLT(P_MUX2_1_3, 1)
	VADC_CHAN_VOLT(P_MUX3_1_3, 1)
	VADC_CHAN_VOLT(P_MUX4_1_3, 1)
	VADC_CHAN_VOLT(P_MUX5_1_3, 1)
	VADC_CHAN_VOLT(P_MUX6_1_3, 1)
	VADC_CHAN_VOLT(P_MUX7_1_3, 1)
	VADC_CHAN_VOLT(P_MUX8_1_3, 1)
	VADC_CHAN_VOLT(P_MUX9_1_3, 1)
	VADC_CHAN_VOLT(P_MUX10_1_3, 1)
	VADC_CHAN_VOLT(P_MUX11_1_3, 1)
	VADC_CHAN_VOLT(P_MUX12_1_3, 1)
	VADC_CHAN_VOLT(P_MUX13_1_3, 1)
	VADC_CHAN_VOLT(P_MUX14_1_3, 1)
	VADC_CHAN_VOLT(P_MUX15_1_3, 1)
	VADC_CHAN_VOLT(P_MUX16_1_3, 1)

	VADC_CHAN_VOLT(LR_MUX1_BAT_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX2_BAT_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_XO_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX4_AMUX_THM1, 0)
	VADC_CHAN_VOLT(LR_MUX5_AMUX_THM2, 0)
	VADC_CHAN_VOLT(LR_MUX6_AMUX_THM3, 0)
	VADC_CHAN_VOLT(LR_MUX7_HW_ID, 0)
	VADC_CHAN_VOLT(LR_MUX8_AMUX_THM4, 0)
	VADC_CHAN_VOLT(LR_MUX9_AMUX_THM5, 0)
	VADC_CHAN_VOLT(LR_MUX10_USB_ID, 0)
	VADC_CHAN_VOLT(AMUX_PU1, 0)
	VADC_CHAN_VOLT(AMUX_PU2, 0)
	VADC_CHAN_VOLT(LR_MUX3_BUF_XO_THERM, 0)

	VADC_CHAN_VOLT(LR_MUX1_PU1_BAT_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX2_PU1_BAT_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_PU1_XO_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX4_PU1_AMUX_THM1, 0)
	VADC_CHAN_VOLT(LR_MUX5_PU1_AMUX_THM2, 0)
	VADC_CHAN_VOLT(LR_MUX6_PU1_AMUX_THM3, 0)
	VADC_CHAN_VOLT(LR_MUX7_PU1_AMUX_HW_ID, 0)
	VADC_CHAN_VOLT(LR_MUX8_PU1_AMUX_THM4, 0)
	VADC_CHAN_VOLT(LR_MUX9_PU1_AMUX_THM5, 0)
	VADC_CHAN_VOLT(LR_MUX10_PU1_AMUX_USB_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_XO_THERM, 0)

	VADC_CHAN_VOLT(LR_MUX1_PU2_BAT_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX2_PU2_BAT_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_PU2_XO_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX4_PU2_AMUX_THM1, 0)
	VADC_CHAN_VOLT(LR_MUX5_PU2_AMUX_THM2, 0)
	VADC_CHAN_VOLT(LR_MUX6_PU2_AMUX_THM3, 0)
	VADC_CHAN_VOLT(LR_MUX7_PU2_AMUX_HW_ID, 0)
	VADC_CHAN_VOLT(LR_MUX8_PU2_AMUX_THM4, 0)
	VADC_CHAN_VOLT(LR_MUX9_PU2_AMUX_THM5, 0)
	VADC_CHAN_VOLT(LR_MUX10_PU2_AMUX_USB_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_BUF_PU2_XO_THERM, 0)

	VADC_CHAN_VOLT(LR_MUX1_PU1_PU2_BAT_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX2_PU1_PU2_BAT_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_PU1_PU2_XO_THERM, 0)
	VADC_CHAN_VOLT(LR_MUX4_PU1_PU2_AMUX_THM1, 0)
	VADC_CHAN_VOLT(LR_MUX5_PU1_PU2_AMUX_THM2, 0)
	VADC_CHAN_VOLT(LR_MUX6_PU1_PU2_AMUX_THM3, 0)
	VADC_CHAN_VOLT(LR_MUX7_PU1_PU2_AMUX_HW_ID, 0)
	VADC_CHAN_VOLT(LR_MUX8_PU1_PU2_AMUX_THM4, 0)
	VADC_CHAN_VOLT(LR_MUX9_PU1_PU2_AMUX_THM5, 0)
	VADC_CHAN_VOLT(LR_MUX10_PU1_PU2_AMUX_USB_ID, 0)
	VADC_CHAN_VOLT(LR_MUX3_BUF_PU1_PU2_XO_THERM, 0)
};

static struct vadc_channels pmp8074_vadc_chans[] = {
	VADC_CHAN_VOLT(PMP8074_GND_REF, 0)
	VADC_CHAN_VOLT(PMP8074_REF_1250MV, 0)
	VADC_CHAN_VOLT(PMP8074_VDD_VADC, 0)
	VADC_CHAN_VOLT(PMP8074_RESERVED1, 0)
	VADC_CHAN_VOLT(PMP8074_RESERVED2, 0)
	VADC_CHAN_VOLT(PMP8074_RESERVED3, 0)
	VADC_CHAN_TEMP(PMP8074_DIE_TEMP, 0)
	VADC_CHAN_TEMP(PMP8074_CHG_TEMP, 0)
	VADC_CHAN_VOLT(PMP8074_USBIN, 0)
	VADC_CHAN_VOLT(PMP8074_IREG_FB, 0)
	VADC_CHAN_VOLT(PMP8074_BAT_THERM, 0)
	VADC_CHAN_VOLT(PMP8074_BAT_ID, 0)
	VADC_CHAN_VOLT(PMP8074_XOTHERM, 0)
	VADC_CHAN_VOLT(PMP8074_AMUX_THM1, 0)
	VADC_CHAN_VOLT(PMP8074_AMUX_THM2, 0)
	VADC_CHAN_VOLT(PMP8074_AMUX_THM3, 0)
};

static int vadc_get_dt_channel_data(struct device *dev,
				    struct vadc_channel_prop *prop,
				    struct device_node *node,
				    struct vadc_channels *vadc_chans,
				    int ch_min, int ch_max)
{
	const char *name = node->name;
	u32 chan, value, varr[2];
	int ret;

	ret = of_property_read_u32(node, "reg", &chan);
	if (ret) {
		dev_err(dev, "invalid channel number %s\n", name);
		return ret;
	}

	if (!vadc_chans) {
		dev_err(dev, "%s No channels specified.\n", name);
		return -EINVAL;
	}

	if (chan < ch_min || chan > ch_max) {
		dev_err(dev, "%s invalid channel number %d\n", name, chan);
		return -EINVAL;
	}

	/* the channel has DT description */
	prop->channel = chan;

	ret = of_property_read_u32(node, "qcom,decimation", &value);
	if (!ret) {
		ret = vadc_decimation_from_dt(value);
		if (ret < 0) {
			dev_err(dev, "%02x invalid decimation %d\n",
				chan, value);
			return ret;
		}
		prop->decimation = ret;
	} else {
		prop->decimation = VADC_DEF_DECIMATION;
	}

	ret = of_property_read_u32_array(node, "qcom,pre-scaling", varr, 2);
	if (!ret) {
		ret = vadc_prescaling_from_dt(varr[0], varr[1]);
		if (ret < 0) {
			dev_err(dev, "%02x invalid pre-scaling <%d %d>\n",
				chan, varr[0], varr[1]);
			return ret;
		}
		prop->prescale = ret;
	} else {
		prop->prescale = vadc_chans[prop->channel].prescale_index;
	}

	ret = of_property_read_u32(node, "qcom,hw-settle-time", &value);
	if (!ret) {
		ret = vadc_hw_settle_time_from_dt(value);
		if (ret < 0) {
			dev_err(dev, "%02x invalid hw-settle-time %d us\n",
				chan, value);
			return ret;
		}
		prop->hw_settle_time = ret;
	} else {
		prop->hw_settle_time = VADC_DEF_HW_SETTLE_TIME;
	}

	ret = of_property_read_u32(node, "qcom,avg-samples", &value);
	if (!ret) {
		ret = vadc_avg_samples_from_dt(value);
		if (ret < 0) {
			dev_err(dev, "%02x invalid avg-samples %d\n",
				chan, value);
			return ret;
		}
		prop->avg_samples = ret;
	} else {
		prop->avg_samples = VADC_DEF_AVG_SAMPLES;
	}

	if (of_property_read_bool(node, "qcom,ratiometric"))
		prop->calibration = VADC_CALIB_RATIOMETRIC;
	else
		prop->calibration = VADC_CALIB_ABSOLUTE;

	dev_dbg(dev, "%02x name %s\n", chan, name);

	return 0;
}

static int vadc_get_dt_data(struct vadc_priv *vadc, struct device_node *node)
{
	struct vadc_channels *vadc_chan;
	struct iio_chan_spec *iio_chan;
	struct vadc_channel_prop prop;
	struct device_node *child;
	struct vadc_channels *vadc_chans;
	unsigned int index = 0;
	int ret;

	vadc->nchannels = of_get_available_child_count(node);
	if (!vadc->nchannels)
		return -EINVAL;

	vadc->iio_chans = devm_kcalloc(vadc->dev, vadc->nchannels,
				       sizeof(*vadc->iio_chans), GFP_KERNEL);
	if (!vadc->iio_chans)
		return -ENOMEM;

	vadc->chan_props = devm_kcalloc(vadc->dev, vadc->nchannels,
					sizeof(*vadc->chan_props), GFP_KERNEL);
	if (!vadc->chan_props)
		return -ENOMEM;

	iio_chan = vadc->iio_chans;

	vadc_chans = vadc->dev_data->vadc_chans;
	if (!vadc_chans)
		return -EINVAL;

	for_each_available_child_of_node(node, child) {
		ret = vadc_get_dt_channel_data(vadc->dev, &prop, child,
					vadc_chans, vadc->dev_data->ch_min,
						vadc->dev_data->ch_max);
		if (ret) {
			of_node_put(child);
			return ret;
		}

		vadc->chan_props[index] = prop;

		vadc_chan = &vadc_chans[prop.channel];

		iio_chan->channel = prop.channel;
		iio_chan->datasheet_name = vadc_chan->datasheet_name;
		iio_chan->info_mask_separate = vadc_chan->info_mask;
		iio_chan->type = vadc_chan->type;
		iio_chan->indexed = 1;
		iio_chan->address = index++;

		iio_chan++;
	}

	if (vadc->dev_data->dynamic_calib) {
		/* These channels are mandatory, they are used as reference points */
		if (!vadc_get_channel(vadc, VADC_REF_1250MV)) {
			dev_err(vadc->dev, "Please define 1.25V channel\n");
			return -ENODEV;
		}

		if (!vadc_get_channel(vadc, VADC_REF_625MV)) {
			dev_err(vadc->dev, "Please define 0.625V channel\n");
			return -ENODEV;
		}

		if (!vadc_get_channel(vadc, VADC_VDD_VADC)) {
			dev_err(vadc->dev, "Please define VDD channel\n");
			return -ENODEV;
		}

		if (!vadc_get_channel(vadc, VADC_GND_REF)) {
			dev_err(vadc->dev, "Please define GND channel\n");
			return -ENODEV;
		}
	}

	return 0;
}

static irqreturn_t vadc_isr(int irq, void *dev_id)
{
	struct vadc_priv *vadc = dev_id;

	complete(&vadc->complete);

	return IRQ_HANDLED;
}

static int vadc_check_revision(struct vadc_priv *vadc)
{
	u8 val;
	int ret;

	ret = vadc_read(vadc, VADC_PERPH_TYPE, &val);
	if (ret)
		return ret;

	if (val < VADC_PERPH_TYPE_ADC) {
		dev_err(vadc->dev, "%d is not ADC\n", val);
		return -ENODEV;
	}

	ret = vadc_read(vadc, VADC_PERPH_SUBTYPE, &val);
	if (ret)
		return ret;

	if (val < VADC_PERPH_SUBTYPE_VADC) {
		dev_err(vadc->dev, "%d is not VADC\n", val);
		return -ENODEV;
	}

	ret = vadc_read(vadc, VADC_REVISION2, &val);
	if (ret)
		return ret;

	if (val < VADC_REVISION2_SUPPORTED_VADC) {
		dev_err(vadc->dev, "revision %d not supported\n", val);
		return -ENODEV;
	}

	return 0;
}

static int pmp8074_get_temp(struct thermal_zone_device *thermal,
			     int *temp)
{
	struct vadc_thermal_data *vadc_therm = thermal->devdata;
	struct vadc_priv *vadc;
	struct vadc_channel_prop *prop;
	u16 adc_code;
	int rc = 0;

	if (!vadc_therm)
		return -EINVAL;

	vadc = vadc_therm->vadc_dev;
	if (!vadc)
		return -EINVAL;

	prop = &(vadc->chan_props[vadc_therm->thermal_chan]);
	if (!prop)
		return -EINVAL;

	rc = vadc_do_conversion(vadc, prop, &adc_code);
	if (rc) {
		pr_err("VADC read error with %d\n", rc);
		return rc;
	}

	/*
	 * Temperature = 506 – (ADC_Counts * 100 /2397)
	 */
	*temp = PMP8074_PA_THERM_BASE
	- ((adc_code * PMP8074_PA_THERM_FACTOR) / PMP8074_PA_THERM_SLOPE);

	return rc;
}

static struct thermal_zone_device_ops pmp8074_thermal_ops = {
	.get_temp = pmp8074_get_temp,
};

#define THERMALNODE_NAME_LENGTH	25
static int32_t vadc_init_thermal(struct vadc_priv *vadc,
					struct platform_device *pdev)
{
	struct device_node *child;
	struct device_node *node = pdev->dev.of_node;
	int i = 0;
	bool thermal_node = false;

	if (node == NULL)
		goto thermal_err_sens;

	if (!vadc->dev_data->thermal_ops) {
		pr_info("No thermal ops to initialize.\n");
		return 0;
	}

	for_each_child_of_node(node, child) {
		char name[THERMALNODE_NAME_LENGTH];

		vadc->vadc_therm_chan[i].thermal_chan = i;
		thermal_node = of_property_read_bool(child,
					"qcom,vadc-thermal-node");
		if (thermal_node) {
			/* Register with the thermal zone */
			snprintf(name, sizeof(name), "%s", child->name);
			vadc->vadc_therm_chan[i].vadc_dev = vadc;
			vadc->vadc_therm_chan[i].tz_dev =
				thermal_zone_device_register(name,
				0, 0, &vadc->vadc_therm_chan[i],
				vadc->dev_data->thermal_ops, NULL, 0, 0);
			if (IS_ERR(vadc->vadc_therm_chan[i].tz_dev)) {
				pr_err("vadc thermal device register failed.\n");
				goto thermal_err_sens;
			}
		}
		i++;
		thermal_node = false;
	}
	return 0;
thermal_err_sens:
	pr_err("VADC thermal init failed.\n");
	return -EINVAL;
}

static struct device_data default_data  = {
	.vadc_chans = default_vadc_chans,
	.reg = reg_offset_default,
	.mode_ctl = true,
	.dynamic_calib = true,
	.force_decimation = true,
	.decimation_mask = 0,
	.ch_min = VADC_USBIN,
	.ch_max = VADC_LR_MUX3_BUF_PU1_PU2_XO_THERM,
	.adc_min = 0x6000,
	.adc_max = 0xa800,
	.uV_max = 1800000,
	.adc_to_uV = NULL,
	.adc_to_degc = NULL,
	.thermal_ops = NULL,
};

static struct device_data pmp8064_data = {
	.vadc_chans = pmp8074_vadc_chans,
	.reg = reg_offset_pmp8074,
	.mode_ctl = false,
	.dynamic_calib = false,
	.force_decimation = false,
	.decimation_mask = 0xc,
	.ch_min = VADC_PMP8074_GND_REF,
	.ch_max = VADC_PMP8074_AMUX_THM3,
	.adc_min = 0x0,
	.adc_max = 0x4000,
	.uV_max = 1875000,
	.adc_to_uV = pmp8074_adc_to_uV,
	.adc_to_degc = pmp8074_adc_to_degc,
	.thermal_ops = &pmp8074_thermal_ops,
};

static const struct of_device_id vadc_match_table[] = {
	{ .compatible = "qcom,spmi-vadc", .data = (void*)&default_data },
	{ .compatible = "qcom,pmp8074-spmi-vadc", .data = (void*)&pmp8064_data },
	{ }
};
MODULE_DEVICE_TABLE(of, vadc_match_table);

static int vadc_probe(struct platform_device *pdev)
{
	const struct of_device_id *id;
	struct device_node *node = pdev->dev.of_node;
	struct device_node *child;
	struct device *dev = &pdev->dev;
	struct iio_dev *indio_dev;
	struct vadc_priv *vadc;
	struct regmap *regmap;
	struct vadc_thermal_data *adc_thermal;
	int ret, irq_eoc, count_adc_channel_list = 0;
	u32 reg;

	id = of_match_device(vadc_match_table, &pdev->dev);
        if (!id || !id->data)
                return -ENODEV;

	regmap = dev_get_regmap(dev->parent, NULL);
	if (!regmap)
		return -ENODEV;

	ret = of_property_read_u32(node, "reg", &reg);
	if (ret < 0)
		return ret;

	for_each_child_of_node(node, child)
		count_adc_channel_list++;

	if (!count_adc_channel_list) {
		pr_err("No channel listing\n");
		return -EINVAL;
	}

	indio_dev = devm_iio_device_alloc(dev, sizeof(*vadc));
	if (!indio_dev)
		return -ENOMEM;

	vadc = iio_priv(indio_dev);

	adc_thermal = devm_kzalloc(dev, (sizeof(struct vadc_thermal_data) *
					count_adc_channel_list), GFP_KERNEL);
	if (!adc_thermal)
		return -ENOMEM;

	vadc->vadc_therm_chan = adc_thermal;

	vadc->dev_data = (struct device_data*)id->data;
	pr_info("SPMI VADC - Min ch: %d Max ch: %d\n",
			vadc->dev_data->ch_min, vadc->dev_data->ch_max);
	vadc->regmap = regmap;
	vadc->dev = dev;
	vadc->base = reg;
	vadc->are_ref_measured = false;
	init_completion(&vadc->complete);
	mutex_init(&vadc->lock);

	ret = vadc_check_revision(vadc);
	if (ret)
		return ret;

	ret = vadc_get_dt_data(vadc, node);
	if (ret)
		return ret;

	irq_eoc = platform_get_irq(pdev, 0);
	if (irq_eoc < 0) {
		if (irq_eoc == -EPROBE_DEFER || irq_eoc == -EINVAL)
			return irq_eoc;
		vadc->poll_eoc = true;
	} else {
		ret = devm_request_irq(dev, irq_eoc, vadc_isr, 0,
				       "spmi-vadc", vadc);
		if (ret)
			return ret;
	}

	ret = vadc_reset(vadc);
	if (ret) {
		dev_err(dev, "reset failed\n");
		return ret;
	}

	if ( vadc->dev_data->dynamic_calib) {
		ret = vadc_measure_ref_points(vadc);
		if (ret)
			return ret;
	}

	indio_dev->dev.parent = dev;
	indio_dev->dev.of_node = node;
	indio_dev->name = pdev->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->info = &vadc_info;
	indio_dev->channels = vadc->iio_chans;
	indio_dev->num_channels = vadc->nchannels;

	ret = devm_iio_device_register(dev, indio_dev);
	if (ret) {
		dev_err(dev, "failed to register iio device - %d\n", ret);
		return ret;
	}

	ret = vadc_init_thermal(vadc, pdev);
	if (ret) {
		dev_err(dev, "failed to initialize thermal adc\n");
		return ret;
	}

	return 0;
}

static struct platform_driver vadc_driver = {
	.driver = {
		   .name = "qcom-spmi-vadc",
		   .of_match_table = vadc_match_table,
	},
	.probe = vadc_probe,
};
module_platform_driver(vadc_driver);

MODULE_ALIAS("platform:qcom-spmi-vadc");
MODULE_DESCRIPTION("Qualcomm SPMI PMIC voltage ADC driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Stanimir Varbanov <svarbanov@mm-sol.com>");
MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");