drivers/iio/adc/ti-ads1100.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * ADS1100 - Texas Instruments Analog-to-Digital Converter
  *
  * Copyright (c) 2023, Topic Embedded Products
  *
  * Datasheet: https://www.ti.com/lit/gpn/ads1100
  * IIO driver for ADS1100 and ADS1000 ADC 16-bit I2C
  */

 #include <linux/bitfield.h>
 #include <linux/bits.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
 #include <linux/mutex.h>
 #include <linux/property.h>
 #include <linux/pm_runtime.h>
 #include <linux/regulator/consumer.h>
 #include <linux/units.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/types.h>

 /* The ADS1100 has a single byte config register */

 /* Conversion in progress bit */
 #define ADS1100_CFG_ST_BSY	BIT(7)
 /* Single conversion bit */
 #define ADS1100_CFG_SC		BIT(4)
 /* Data rate */
 #define ADS1100_DR_MASK		GENMASK(3, 2)
 /* Gain */
 #define ADS1100_PGA_MASK	GENMASK(1, 0)

 #define ADS1100_CONTINUOUS	0
 #define	ADS1100_SINGLESHOT	ADS1100_CFG_SC

 #define ADS1100_SLEEP_DELAY_MS	2000

 static const int ads1100_data_rate[] = { 128, 32, 16, 8 };
 static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 };

 struct ads1100_data {
 	struct i2c_client *client;
 	struct regulator *reg_vdd;
 	struct mutex lock;
 	int scale_avail[2 * 4]; /* 4 gain settings */
 	u8 config;
 	bool supports_data_rate; /* Only the ADS1100 can select the rate */
 };

 static const struct iio_chan_spec ads1100_channel = {
 	.type = IIO_VOLTAGE,
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 	.info_mask_shared_by_all =
 	    BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.info_mask_shared_by_all_available =
 	    BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 	.scan_type = {
 		      .sign = 's',
 		      .realbits = 16,
 		      .storagebits = 16,
 		      .endianness = IIO_CPU,
 		       },
 	.datasheet_name = "AIN",
 };

 static int ads1100_set_config_bits(struct ads1100_data *data, u8 mask, u8 value)
 {
 	int ret;
 	u8 config = (data->config & ~mask) | (value & mask);

 	if (data->config == config)
 		return 0;	/* Already done */

 	ret = i2c_master_send(data->client, &config, 1);
 	if (ret < 0)
 		return ret;

 	data->config = config;

 	return 0;
 };

 static int ads1100_data_bits(struct ads1100_data *data)
 {
 	return ads1100_data_rate_bits[FIELD_GET(ADS1100_DR_MASK, data->config)];
 }

 static int ads1100_get_adc_result(struct ads1100_data *data, int chan, int *val)
 {
 	int ret;
 	__be16 buffer;
 	s16 value;

 	if (chan != 0)
 		return -EINVAL;

 	ret = pm_runtime_resume_and_get(&data->client->dev);
 	if (ret < 0)
 		return ret;

 	ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));

 	pm_runtime_mark_last_busy(&data->client->dev);
 	pm_runtime_put_autosuspend(&data->client->dev);

 	if (ret < 0) {
 		dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
 		return ret;
 	}

 	/* Value is always 16-bit 2's complement */
 	value = be16_to_cpu(buffer);

 	/* Shift result to compensate for bit resolution vs. sample rate */
 	value <<= 16 - ads1100_data_bits(data);

 	*val = sign_extend32(value, 15);

 	return 0;
 }

 static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
 {
 	int microvolts;
 	int gain;

 	/* With Vdd between 2.7 and 5V, the scale is always below 1 */
 	if (val)
 		return -EINVAL;

 	if (!val2)
 		return -EINVAL;

 	microvolts = regulator_get_voltage(data->reg_vdd);
 	/*
 	 * val2 is in 'micro' units, n = val2 / 1000000
 	 * result must be millivolts, d = microvolts / 1000
 	 * the full-scale value is d/n, corresponds to 2^15,
 	 * hence the gain = (d / n) >> 15, factoring out the 1000 and moving the
 	 * bitshift so everything fits in 32-bits yields this formula.
 	 */
 	gain = DIV_ROUND_CLOSEST(microvolts, BIT(15)) * MILLI / val2;
 	if (gain < BIT(0) || gain > BIT(3))
 		return -EINVAL;

 	ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1);

 	return 0;
 }

 static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate)
 {
 	unsigned int i;
 	unsigned int size;

 	size = data->supports_data_rate ? ARRAY_SIZE(ads1100_data_rate) : 1;
 	for (i = 0; i < size; i++) {
 		if (ads1100_data_rate[i] == rate)
 			return ads1100_set_config_bits(data, ADS1100_DR_MASK,
 						       FIELD_PREP(ADS1100_DR_MASK, i));
 	}

 	return -EINVAL;
 }

 static int ads1100_get_vdd_millivolts(struct ads1100_data *data)
 {
 	return regulator_get_voltage(data->reg_vdd) / (MICRO / MILLI);
 }

 static void ads1100_calc_scale_avail(struct ads1100_data *data)
 {
 	int millivolts = ads1100_get_vdd_millivolts(data);
 	unsigned int i;

 	for (i = 0; i < ARRAY_SIZE(data->scale_avail) / 2; i++) {
 		data->scale_avail[i * 2 + 0] = millivolts;
 		data->scale_avail[i * 2 + 1] = 15 + i;
 	}
 }

 static int ads1100_read_avail(struct iio_dev *indio_dev,
 			      struct iio_chan_spec const *chan,
 			      const int **vals, int *type, int *length,
 			      long mask)
 {
 	struct ads1100_data *data = iio_priv(indio_dev);

 	if (chan->type != IIO_VOLTAGE)
 		return -EINVAL;

 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*type = IIO_VAL_INT;
 		*vals = ads1100_data_rate;
 		if (data->supports_data_rate)
 			*length = ARRAY_SIZE(ads1100_data_rate);
 		else
 			*length = 1;
 		return IIO_AVAIL_LIST;
 	case IIO_CHAN_INFO_SCALE:
 		*type = IIO_VAL_FRACTIONAL_LOG2;
 		*vals = data->scale_avail;
 		*length = ARRAY_SIZE(data->scale_avail);
 		return IIO_AVAIL_LIST;
 	default:
 		return -EINVAL;
 	}
 }

 static int ads1100_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan, int *val,
 			    int *val2, long mask)
 {
 	int ret;
 	struct ads1100_data *data = iio_priv(indio_dev);

 	mutex_lock(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
 			break;

 		ret = ads1100_get_adc_result(data, chan->address, val);
 		if (ret >= 0)
 			ret = IIO_VAL_INT;
 		iio_device_release_direct_mode(indio_dev);
 		break;
 	case IIO_CHAN_INFO_SCALE:
 		/* full-scale is the supply voltage in millivolts */
 		*val = ads1100_get_vdd_millivolts(data);
 		*val2 = 15 + FIELD_GET(ADS1100_PGA_MASK, data->config);
 		ret = IIO_VAL_FRACTIONAL_LOG2;
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*val = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK,
 						   data->config)];
 		ret = IIO_VAL_INT;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
 	mutex_unlock(&data->lock);

 	return ret;
 }

 static int ads1100_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan, int val,
 			     int val2, long mask)
 {
 	struct ads1100_data *data = iio_priv(indio_dev);
 	int ret;

 	mutex_lock(&data->lock);
 	switch (mask) {
 	case IIO_CHAN_INFO_SCALE:
 		ret = ads1100_set_scale(data, val, val2);
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		ret = ads1100_set_data_rate(data, chan->address, val);
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
 	mutex_unlock(&data->lock);

 	return ret;
 }

 static const struct iio_info ads1100_info = {
 	.read_avail = ads1100_read_avail,
 	.read_raw = ads1100_read_raw,
 	.write_raw = ads1100_write_raw,
 };

 static int ads1100_setup(struct ads1100_data *data)
 {
 	int ret;
 	u8 buffer[3];

 	/* Setup continuous sampling mode at 8sps */
 	buffer[0] = ADS1100_DR_MASK | ADS1100_CONTINUOUS;
 	ret = i2c_master_send(data->client, buffer, 1);
 	if (ret < 0)
 		return ret;

 	ret = i2c_master_recv(data->client, buffer, sizeof(buffer));
 	if (ret < 0)
 		return ret;

 	/* Config register returned in third byte, strip away the busy status */
 	data->config = buffer[2] & ~ADS1100_CFG_ST_BSY;

 	/* Detect the sample rate capability by checking the DR bits */
 	data->supports_data_rate = FIELD_GET(ADS1100_DR_MASK, buffer[2]) != 0;

 	return 0;
 }

 static void ads1100_reg_disable(void *reg)
 {
 	regulator_disable(reg);
 }

 static void ads1100_disable_continuous(void *data)
 {
 	ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
 }

 static int ads1100_probe(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev;
 	struct ads1100_data *data;
 	struct device *dev = &client->dev;
 	int ret;

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

 	data = iio_priv(indio_dev);
 	dev_set_drvdata(dev, data);
 	data->client = client;
 	mutex_init(&data->lock);

 	indio_dev->name = "ads1100";
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = &ads1100_channel;
 	indio_dev->num_channels = 1;
 	indio_dev->info = &ads1100_info;

 	data->reg_vdd = devm_regulator_get(dev, "vdd");
 	if (IS_ERR(data->reg_vdd))
 		return dev_err_probe(dev, PTR_ERR(data->reg_vdd),
 				     "Failed to get vdd regulator\n");

 	ret = regulator_enable(data->reg_vdd);
 	if (ret < 0)
 		return dev_err_probe(dev, ret,
 				     "Failed to enable vdd regulator\n");

 	ret = devm_add_action_or_reset(dev, ads1100_reg_disable, data->reg_vdd);
 	if (ret)
 		return ret;

 	ret = ads1100_setup(data);
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "Failed to communicate with device\n");

 	ret = devm_add_action_or_reset(dev, ads1100_disable_continuous, data);
 	if (ret)
 		return ret;

 	ads1100_calc_scale_avail(data);

 	pm_runtime_set_autosuspend_delay(dev, ADS1100_SLEEP_DELAY_MS);
 	pm_runtime_use_autosuspend(dev);
 	pm_runtime_set_active(dev);
 	ret = devm_pm_runtime_enable(dev);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to enable pm_runtime\n");

 	ret = devm_iio_device_register(dev, indio_dev);
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "Failed to register IIO device\n");

 	return 0;
 }

 static int ads1100_runtime_suspend(struct device *dev)
 {
 	struct ads1100_data *data = dev_get_drvdata(dev);

 	ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
 	regulator_disable(data->reg_vdd);

 	return 0;
 }

 static int ads1100_runtime_resume(struct device *dev)
 {
 	struct ads1100_data *data = dev_get_drvdata(dev);
 	int ret;

 	ret = regulator_enable(data->reg_vdd);
 	if (ret) {
 		dev_err(&data->client->dev, "Failed to enable Vdd\n");
 		return ret;
 	}

 	/*
 	 * We'll always change the mode bit in the config register, so there is
 	 * no need here to "force" a write to the config register. If the device
 	 * has been power-cycled, we'll re-write its config register now.
 	 */
 	return ads1100_set_config_bits(data, ADS1100_CFG_SC,
 				       ADS1100_CONTINUOUS);
 }

 static DEFINE_RUNTIME_DEV_PM_OPS(ads1100_pm_ops,
 				 ads1100_runtime_suspend,
 				 ads1100_runtime_resume,
 				 NULL);

 static const struct i2c_device_id ads1100_id[] = {
 	{ "ads1100" },
 	{ "ads1000" },
 	{ }
 };

 MODULE_DEVICE_TABLE(i2c, ads1100_id);

 static const struct of_device_id ads1100_of_match[] = {
 	{.compatible = "ti,ads1100" },
 	{.compatible = "ti,ads1000" },
 	{ }
 };

 MODULE_DEVICE_TABLE(of, ads1100_of_match);

 static struct i2c_driver ads1100_driver = {
 	.driver = {
 		   .name = "ads1100",
 		   .of_match_table = ads1100_of_match,
 		   .pm = pm_ptr(&ads1100_pm_ops),
 	},
 	.probe_new = ads1100_probe,
 	.id_table = ads1100_id,
 };

 module_i2c_driver(ads1100_driver);

 MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
 MODULE_DESCRIPTION("Texas Instruments ADS1100 ADC driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* ADS1100 - Texas Instruments Analog-to-Digital Converter
	*
	* Copyright (c) 2023, Topic Embedded Products
	*
	* Datasheet: https://www.ti.com/lit/gpn/ads1100
	* IIO driver for ADS1100 and ADS1000 ADC 16-bit I2C
	*/

	#include <linux/bitfield.h>
	#include <linux/bits.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/i2c.h>
	#include <linux/mutex.h>
	#include <linux/property.h>
	#include <linux/pm_runtime.h>
	#include <linux/regulator/consumer.h>
	#include <linux/units.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/types.h>

	/* The ADS1100 has a single byte config register */

	/* Conversion in progress bit */
	#define ADS1100_CFG_ST_BSY BIT(7)
	/* Single conversion bit */
	#define ADS1100_CFG_SC BIT(4)
	/* Data rate */
	#define ADS1100_DR_MASK GENMASK(3, 2)
	/* Gain */
	#define ADS1100_PGA_MASK GENMASK(1, 0)

	#define ADS1100_CONTINUOUS 0
	#define ADS1100_SINGLESHOT ADS1100_CFG_SC

	#define ADS1100_SLEEP_DELAY_MS 2000

	static const int ads1100_data_rate[] = { 128, 32, 16, 8 };
	static const int ads1100_data_rate_bits[] = { 12, 14, 15, 16 };

	struct ads1100_data {
	struct i2c_client *client;
	struct regulator *reg_vdd;
	struct mutex lock;
	int scale_avail[2 * 4]; /* 4 gain settings */
	u8 config;
	bool supports_data_rate; /* Only the ADS1100 can select the rate */
	};

	static const struct iio_chan_spec ads1100_channel = {
	.type = IIO_VOLTAGE,
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	.info_mask_shared_by_all =
	BIT(IIO_CHAN_INFO_SCALE) \| BIT(IIO_CHAN_INFO_SAMP_FREQ),
	.info_mask_shared_by_all_available =
	BIT(IIO_CHAN_INFO_SCALE) \| BIT(IIO_CHAN_INFO_SAMP_FREQ),
	.scan_type = {
	.sign = 's',
	.realbits = 16,
	.storagebits = 16,
	.endianness = IIO_CPU,
	},
	.datasheet_name = "AIN",
	};

	static int ads1100_set_config_bits(struct ads1100_data *data, u8 mask, u8 value)
	{
	int ret;
	u8 config = (data->config & ~mask) \| (value & mask);

	if (data->config == config)
	return 0; /* Already done */

	ret = i2c_master_send(data->client, &config, 1);
	if (ret < 0)
	return ret;

	data->config = config;

	return 0;
	};

	static int ads1100_data_bits(struct ads1100_data *data)
	{
	return ads1100_data_rate_bits[FIELD_GET(ADS1100_DR_MASK, data->config)];
	}

	static int ads1100_get_adc_result(struct ads1100_data data, int chan, int val)
	{
	int ret;
	__be16 buffer;
	s16 value;

	if (chan != 0)
	return -EINVAL;

	ret = pm_runtime_resume_and_get(&data->client->dev);
	if (ret < 0)
	return ret;

	ret = i2c_master_recv(data->client, (char *)&buffer, sizeof(buffer));

	pm_runtime_mark_last_busy(&data->client->dev);
	pm_runtime_put_autosuspend(&data->client->dev);

	if (ret < 0) {
	dev_err(&data->client->dev, "I2C read fail: %d\n", ret);
	return ret;
	}

	/* Value is always 16-bit 2's complement */
	value = be16_to_cpu(buffer);

	/* Shift result to compensate for bit resolution vs. sample rate */
	value <<= 16 - ads1100_data_bits(data);

	*val = sign_extend32(value, 15);

	return 0;
	}

	static int ads1100_set_scale(struct ads1100_data *data, int val, int val2)
	{
	int microvolts;
	int gain;

	/* With Vdd between 2.7 and 5V, the scale is always below 1 */
	if (val)
	return -EINVAL;

	if (!val2)
	return -EINVAL;

	microvolts = regulator_get_voltage(data->reg_vdd);
	/*
	* val2 is in 'micro' units, n = val2 / 1000000
	* result must be millivolts, d = microvolts / 1000
	* the full-scale value is d/n, corresponds to 2^15,
	* hence the gain = (d / n) >> 15, factoring out the 1000 and moving the
	* bitshift so everything fits in 32-bits yields this formula.
	*/
	gain = DIV_ROUND_CLOSEST(microvolts, BIT(15)) * MILLI / val2;
	if (gain < BIT(0) \|\| gain > BIT(3))
	return -EINVAL;

	ads1100_set_config_bits(data, ADS1100_PGA_MASK, ffs(gain) - 1);

	return 0;
	}

	static int ads1100_set_data_rate(struct ads1100_data *data, int chan, int rate)
	{
	unsigned int i;
	unsigned int size;

	size = data->supports_data_rate ? ARRAY_SIZE(ads1100_data_rate) : 1;
	for (i = 0; i < size; i++) {
	if (ads1100_data_rate[i] == rate)
	return ads1100_set_config_bits(data, ADS1100_DR_MASK,
	FIELD_PREP(ADS1100_DR_MASK, i));
	}

	return -EINVAL;
	}

	static int ads1100_get_vdd_millivolts(struct ads1100_data *data)
	{
	return regulator_get_voltage(data->reg_vdd) / (MICRO / MILLI);
	}

	static void ads1100_calc_scale_avail(struct ads1100_data *data)
	{
	int millivolts = ads1100_get_vdd_millivolts(data);
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(data->scale_avail) / 2; i++) {
	data->scale_avail[i * 2 + 0] = millivolts;
	data->scale_avail[i * 2 + 1] = 15 + i;
	}
	}

	static int ads1100_read_avail(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	const int *vals, int type, int *length,
	long mask)
	{
	struct ads1100_data *data = iio_priv(indio_dev);

	if (chan->type != IIO_VOLTAGE)
	return -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
	*type = IIO_VAL_INT;
	*vals = ads1100_data_rate;
	if (data->supports_data_rate)
	*length = ARRAY_SIZE(ads1100_data_rate);
	else
	*length = 1;
	return IIO_AVAIL_LIST;
	case IIO_CHAN_INFO_SCALE:
	*type = IIO_VAL_FRACTIONAL_LOG2;
	*vals = data->scale_avail;
	*length = ARRAY_SIZE(data->scale_avail);
	return IIO_AVAIL_LIST;
	default:
	return -EINVAL;
	}
	}

	static int ads1100_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const chan, int val,
	int *val2, long mask)
	{
	int ret;
	struct ads1100_data *data = iio_priv(indio_dev);

	mutex_lock(&data->lock);
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	ret = iio_device_claim_direct_mode(indio_dev);
	if (ret)
	break;

	ret = ads1100_get_adc_result(data, chan->address, val);
	if (ret >= 0)
	ret = IIO_VAL_INT;
	iio_device_release_direct_mode(indio_dev);
	break;
	case IIO_CHAN_INFO_SCALE:
	/* full-scale is the supply voltage in millivolts */
	*val = ads1100_get_vdd_millivolts(data);
	*val2 = 15 + FIELD_GET(ADS1100_PGA_MASK, data->config);
	ret = IIO_VAL_FRACTIONAL_LOG2;
	break;
	case IIO_CHAN_INFO_SAMP_FREQ:
	*val = ads1100_data_rate[FIELD_GET(ADS1100_DR_MASK,
	data->config)];
	ret = IIO_VAL_INT;
	break;
	default:
	ret = -EINVAL;
	break;
	}
	mutex_unlock(&data->lock);

	return ret;
	}

	static int ads1100_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan, int val,
	int val2, long mask)
	{
	struct ads1100_data *data = iio_priv(indio_dev);
	int ret;

	mutex_lock(&data->lock);
	switch (mask) {
	case IIO_CHAN_INFO_SCALE:
	ret = ads1100_set_scale(data, val, val2);
	break;
	case IIO_CHAN_INFO_SAMP_FREQ:
	ret = ads1100_set_data_rate(data, chan->address, val);
	break;
	default:
	ret = -EINVAL;
	break;
	}
	mutex_unlock(&data->lock);

	return ret;
	}

	static const struct iio_info ads1100_info = {
	.read_avail = ads1100_read_avail,
	.read_raw = ads1100_read_raw,
	.write_raw = ads1100_write_raw,
	};

	static int ads1100_setup(struct ads1100_data *data)
	{
	int ret;
	u8 buffer[3];

	/* Setup continuous sampling mode at 8sps */
	buffer[0] = ADS1100_DR_MASK \| ADS1100_CONTINUOUS;
	ret = i2c_master_send(data->client, buffer, 1);
	if (ret < 0)
	return ret;

	ret = i2c_master_recv(data->client, buffer, sizeof(buffer));
	if (ret < 0)
	return ret;

	/* Config register returned in third byte, strip away the busy status */
	data->config = buffer[2] & ~ADS1100_CFG_ST_BSY;

	/* Detect the sample rate capability by checking the DR bits */
	data->supports_data_rate = FIELD_GET(ADS1100_DR_MASK, buffer[2]) != 0;

	return 0;
	}

	static void ads1100_reg_disable(void *reg)
	{
	regulator_disable(reg);
	}

	static void ads1100_disable_continuous(void *data)
	{
	ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
	}

	static int ads1100_probe(struct i2c_client *client)
	{
	struct iio_dev *indio_dev;
	struct ads1100_data *data;
	struct device *dev = &client->dev;
	int ret;

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

	data = iio_priv(indio_dev);
	dev_set_drvdata(dev, data);
	data->client = client;
	mutex_init(&data->lock);

	indio_dev->name = "ads1100";
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = &ads1100_channel;
	indio_dev->num_channels = 1;
	indio_dev->info = &ads1100_info;

	data->reg_vdd = devm_regulator_get(dev, "vdd");
	if (IS_ERR(data->reg_vdd))
	return dev_err_probe(dev, PTR_ERR(data->reg_vdd),
	"Failed to get vdd regulator\n");

	ret = regulator_enable(data->reg_vdd);
	if (ret < 0)
	return dev_err_probe(dev, ret,
	"Failed to enable vdd regulator\n");

	ret = devm_add_action_or_reset(dev, ads1100_reg_disable, data->reg_vdd);
	if (ret)
	return ret;

	ret = ads1100_setup(data);
	if (ret)
	return dev_err_probe(dev, ret,
	"Failed to communicate with device\n");

	ret = devm_add_action_or_reset(dev, ads1100_disable_continuous, data);
	if (ret)
	return ret;

	ads1100_calc_scale_avail(data);

	pm_runtime_set_autosuspend_delay(dev, ADS1100_SLEEP_DELAY_MS);
	pm_runtime_use_autosuspend(dev);
	pm_runtime_set_active(dev);
	ret = devm_pm_runtime_enable(dev);
	if (ret)
	return dev_err_probe(dev, ret, "Failed to enable pm_runtime\n");

	ret = devm_iio_device_register(dev, indio_dev);
	if (ret)
	return dev_err_probe(dev, ret,
	"Failed to register IIO device\n");

	return 0;
	}

	static int ads1100_runtime_suspend(struct device *dev)
	{
	struct ads1100_data *data = dev_get_drvdata(dev);

	ads1100_set_config_bits(data, ADS1100_CFG_SC, ADS1100_SINGLESHOT);
	regulator_disable(data->reg_vdd);

	return 0;
	}

	static int ads1100_runtime_resume(struct device *dev)
	{
	struct ads1100_data *data = dev_get_drvdata(dev);
	int ret;

	ret = regulator_enable(data->reg_vdd);
	if (ret) {
	dev_err(&data->client->dev, "Failed to enable Vdd\n");
	return ret;
	}

	/*
	* We'll always change the mode bit in the config register, so there is
	* no need here to "force" a write to the config register. If the device
	* has been power-cycled, we'll re-write its config register now.
	*/
	return ads1100_set_config_bits(data, ADS1100_CFG_SC,
	ADS1100_CONTINUOUS);
	}

	static DEFINE_RUNTIME_DEV_PM_OPS(ads1100_pm_ops,
	ads1100_runtime_suspend,
	ads1100_runtime_resume,
	NULL);

	static const struct i2c_device_id ads1100_id[] = {
	{ "ads1100" },
	{ "ads1000" },
	{ }
	};

	MODULE_DEVICE_TABLE(i2c, ads1100_id);

	static const struct of_device_id ads1100_of_match[] = {
	{.compatible = "ti,ads1100" },
	{.compatible = "ti,ads1000" },
	{ }
	};

	MODULE_DEVICE_TABLE(of, ads1100_of_match);

	static struct i2c_driver ads1100_driver = {
	.driver = {
	.name = "ads1100",
	.of_match_table = ads1100_of_match,
	.pm = pm_ptr(&ads1100_pm_ops),
	},
	.probe_new = ads1100_probe,
	.id_table = ads1100_id,
	};

	module_i2c_driver(ads1100_driver);

	MODULE_AUTHOR("Mike Looijmans <mike.looijmans@topic.nl>");
	MODULE_DESCRIPTION("Texas Instruments ADS1100 ADC driver");
	MODULE_LICENSE("GPL");