drivers/iio/health/afe4404.c - LeafOS-Devices/android_kernel_samsung_gta4xl - Gitiles

 /*
  * AFE4404 Heart Rate Monitors and Low-Cost Pulse Oximeters
  *
  * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
  *	Andrew F. Davis <afd@ti.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.
  */

 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/sysfs.h>
 #include <linux/regulator/consumer.h>

 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/trigger.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>

 #include "afe440x.h"

 #define AFE4404_DRIVER_NAME		"afe4404"

 /* AFE4404 registers */
 #define AFE4404_TIA_GAIN_SEP		0x20
 #define AFE4404_TIA_GAIN		0x21
 #define AFE4404_PROG_TG_STC		0x34
 #define AFE4404_PROG_TG_ENDC		0x35
 #define AFE4404_LED3LEDSTC		0x36
 #define AFE4404_LED3LEDENDC		0x37
 #define AFE4404_CLKDIV_PRF		0x39
 #define AFE4404_OFFDAC			0x3a
 #define AFE4404_DEC			0x3d
 #define AFE4404_AVG_LED2_ALED2VAL	0x3f
 #define AFE4404_AVG_LED1_ALED1VAL	0x40

 /* AFE4404 CONTROL2 register fields */
 #define AFE440X_CONTROL2_OSC_ENABLE	BIT(9)

 enum afe4404_fields {
 	/* Gains */
 	F_TIA_GAIN_SEP, F_TIA_CF_SEP,
 	F_TIA_GAIN, TIA_CF,

 	/* LED Current */
 	F_ILED1, F_ILED2, F_ILED3,

 	/* Offset DAC */
 	F_OFFDAC_AMB2, F_OFFDAC_LED1, F_OFFDAC_AMB1, F_OFFDAC_LED2,

 	/* sentinel */
 	F_MAX_FIELDS
 };

 static const struct reg_field afe4404_reg_fields[] = {
 	/* Gains */
 	[F_TIA_GAIN_SEP]	= REG_FIELD(AFE4404_TIA_GAIN_SEP, 0, 2),
 	[F_TIA_CF_SEP]		= REG_FIELD(AFE4404_TIA_GAIN_SEP, 3, 5),
 	[F_TIA_GAIN]		= REG_FIELD(AFE4404_TIA_GAIN, 0, 2),
 	[TIA_CF]		= REG_FIELD(AFE4404_TIA_GAIN, 3, 5),
 	/* LED Current */
 	[F_ILED1]		= REG_FIELD(AFE440X_LEDCNTRL, 0, 5),
 	[F_ILED2]		= REG_FIELD(AFE440X_LEDCNTRL, 6, 11),
 	[F_ILED3]		= REG_FIELD(AFE440X_LEDCNTRL, 12, 17),
 	/* Offset DAC */
 	[F_OFFDAC_AMB2]		= REG_FIELD(AFE4404_OFFDAC, 0, 4),
 	[F_OFFDAC_LED1]		= REG_FIELD(AFE4404_OFFDAC, 5, 9),
 	[F_OFFDAC_AMB1]		= REG_FIELD(AFE4404_OFFDAC, 10, 14),
 	[F_OFFDAC_LED2]		= REG_FIELD(AFE4404_OFFDAC, 15, 19),
 };

 /**
  * struct afe4404_data - AFE4404 device instance data
  * @dev: Device structure
  * @regmap: Register map of the device
  * @fields: Register fields of the device
  * @regulator: Pointer to the regulator for the IC
  * @trig: IIO trigger for this device
  * @irq: ADC_RDY line interrupt number
  */
 struct afe4404_data {
 	struct device *dev;
 	struct regmap *regmap;
 	struct regmap_field *fields[F_MAX_FIELDS];
 	struct regulator *regulator;
 	struct iio_trigger *trig;
 	int irq;
 };

 enum afe4404_chan_id {
 	LED2 = 1,
 	ALED2,
 	LED1,
 	ALED1,
 	LED2_ALED2,
 	LED1_ALED1,
 };

 static const unsigned int afe4404_channel_values[] = {
 	[LED2] = AFE440X_LED2VAL,
 	[ALED2] = AFE440X_ALED2VAL,
 	[LED1] = AFE440X_LED1VAL,
 	[ALED1] = AFE440X_ALED1VAL,
 	[LED2_ALED2] = AFE440X_LED2_ALED2VAL,
 	[LED1_ALED1] = AFE440X_LED1_ALED1VAL,
 };

 static const unsigned int afe4404_channel_leds[] = {
 	[LED2] = F_ILED2,
 	[ALED2] = F_ILED3,
 	[LED1] = F_ILED1,
 };

 static const unsigned int afe4404_channel_offdacs[] = {
 	[LED2] = F_OFFDAC_LED2,
 	[ALED2] = F_OFFDAC_AMB2,
 	[LED1] = F_OFFDAC_LED1,
 	[ALED1] = F_OFFDAC_AMB1,
 };

 static const struct iio_chan_spec afe4404_channels[] = {
 	/* ADC values */
 	AFE440X_INTENSITY_CHAN(LED2, BIT(IIO_CHAN_INFO_OFFSET)),
 	AFE440X_INTENSITY_CHAN(ALED2, BIT(IIO_CHAN_INFO_OFFSET)),
 	AFE440X_INTENSITY_CHAN(LED1, BIT(IIO_CHAN_INFO_OFFSET)),
 	AFE440X_INTENSITY_CHAN(ALED1, BIT(IIO_CHAN_INFO_OFFSET)),
 	AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
 	AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
 	/* LED current */
 	AFE440X_CURRENT_CHAN(LED2),
 	AFE440X_CURRENT_CHAN(ALED2),
 	AFE440X_CURRENT_CHAN(LED1),
 };

 static const struct afe440x_val_table afe4404_res_table[] = {
 	{ .integer = 500000, .fract = 0 },
 	{ .integer = 250000, .fract = 0 },
 	{ .integer = 100000, .fract = 0 },
 	{ .integer = 50000, .fract = 0 },
 	{ .integer = 25000, .fract = 0 },
 	{ .integer = 10000, .fract = 0 },
 	{ .integer = 1000000, .fract = 0 },
 	{ .integer = 2000000, .fract = 0 },
 };
 AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4404_res_table);

 static const struct afe440x_val_table afe4404_cap_table[] = {
 	{ .integer = 0, .fract = 5000 },
 	{ .integer = 0, .fract = 2500 },
 	{ .integer = 0, .fract = 10000 },
 	{ .integer = 0, .fract = 7500 },
 	{ .integer = 0, .fract = 20000 },
 	{ .integer = 0, .fract = 17500 },
 	{ .integer = 0, .fract = 25000 },
 	{ .integer = 0, .fract = 22500 },
 };
 AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4404_cap_table);

 static ssize_t afe440x_show_register(struct device *dev,
 				     struct device_attribute *attr,
 				     char *buf)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 	unsigned int reg_val;
 	int vals[2];
 	int ret;

 	ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
 	if (ret)
 		return ret;

 	if (reg_val >= afe440x_attr->table_size)
 		return -EINVAL;

 	vals[0] = afe440x_attr->val_table[reg_val].integer;
 	vals[1] = afe440x_attr->val_table[reg_val].fract;

 	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
 }

 static ssize_t afe440x_store_register(struct device *dev,
 				      struct device_attribute *attr,
 				      const char *buf, size_t count)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
 	int val, integer, fract, ret;

 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
 	if (ret)
 		return ret;

 	for (val = 0; val < afe440x_attr->table_size; val++)
 		if (afe440x_attr->val_table[val].integer == integer &&
 		    afe440x_attr->val_table[val].fract == fract)
 			break;
 	if (val == afe440x_attr->table_size)
 		return -EINVAL;

 	ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
 	if (ret)
 		return ret;

 	return count;
 }

 static AFE440X_ATTR(in_intensity1_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
 static AFE440X_ATTR(in_intensity1_capacitance, F_TIA_CF_SEP, afe4404_cap_table);

 static AFE440X_ATTR(in_intensity2_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
 static AFE440X_ATTR(in_intensity2_capacitance, F_TIA_CF_SEP, afe4404_cap_table);

 static AFE440X_ATTR(in_intensity3_resistance, F_TIA_GAIN, afe4404_res_table);
 static AFE440X_ATTR(in_intensity3_capacitance, TIA_CF, afe4404_cap_table);

 static AFE440X_ATTR(in_intensity4_resistance, F_TIA_GAIN, afe4404_res_table);
 static AFE440X_ATTR(in_intensity4_capacitance, TIA_CF, afe4404_cap_table);

 static struct attribute *afe440x_attributes[] = {
 	&dev_attr_in_intensity_resistance_available.attr,
 	&dev_attr_in_intensity_capacitance_available.attr,
 	&afe440x_attr_in_intensity1_resistance.dev_attr.attr,
 	&afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
 	&afe440x_attr_in_intensity2_resistance.dev_attr.attr,
 	&afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
 	&afe440x_attr_in_intensity3_resistance.dev_attr.attr,
 	&afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
 	&afe440x_attr_in_intensity4_resistance.dev_attr.attr,
 	&afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group afe440x_attribute_group = {
 	.attrs = afe440x_attributes
 };

 static int afe4404_read_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int *val, int *val2, long mask)
 {
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	unsigned int value_reg = afe4404_channel_values[chan->address];
 	unsigned int led_field = afe4404_channel_leds[chan->address];
 	unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
 	int ret;

 	switch (chan->type) {
 	case IIO_INTENSITY:
 		switch (mask) {
 		case IIO_CHAN_INFO_RAW:
 			ret = regmap_read(afe->regmap, value_reg, val);
 			if (ret)
 				return ret;
 			return IIO_VAL_INT;
 		case IIO_CHAN_INFO_OFFSET:
 			ret = regmap_field_read(afe->fields[offdac_field], val);
 			if (ret)
 				return ret;
 			return IIO_VAL_INT;
 		}
 		break;
 	case IIO_CURRENT:
 		switch (mask) {
 		case IIO_CHAN_INFO_RAW:
 			ret = regmap_field_read(afe->fields[led_field], val);
 			if (ret)
 				return ret;
 			return IIO_VAL_INT;
 		case IIO_CHAN_INFO_SCALE:
 			*val = 0;
 			*val2 = 800000;
 			return IIO_VAL_INT_PLUS_MICRO;
 		}
 		break;
 	default:
 		break;
 	}

 	return -EINVAL;
 }

 static int afe4404_write_raw(struct iio_dev *indio_dev,
 			     struct iio_chan_spec const *chan,
 			     int val, int val2, long mask)
 {
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	unsigned int led_field = afe4404_channel_leds[chan->address];
 	unsigned int offdac_field = afe4404_channel_offdacs[chan->address];

 	switch (chan->type) {
 	case IIO_INTENSITY:
 		switch (mask) {
 		case IIO_CHAN_INFO_OFFSET:
 			return regmap_field_write(afe->fields[offdac_field], val);
 		}
 		break;
 	case IIO_CURRENT:
 		switch (mask) {
 		case IIO_CHAN_INFO_RAW:
 			return regmap_field_write(afe->fields[led_field], val);
 		}
 		break;
 	default:
 		break;
 	}

 	return -EINVAL;
 }

 static const struct iio_info afe4404_iio_info = {
 	.attrs = &afe440x_attribute_group,
 	.read_raw = afe4404_read_raw,
 	.write_raw = afe4404_write_raw,
 	.driver_module = THIS_MODULE,
 };

 static irqreturn_t afe4404_trigger_handler(int irq, void *private)
 {
 	struct iio_poll_func *pf = private;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	int ret, bit, i = 0;
 	s32 buffer[10];

 	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
 		ret = regmap_read(afe->regmap, afe4404_channel_values[bit],
 				  &buffer[i++]);
 		if (ret)
 			goto err;
 	}

 	iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
 err:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static const struct iio_trigger_ops afe4404_trigger_ops = {
 	.owner = THIS_MODULE,
 };

 /* Default timings from data-sheet */
 #define AFE4404_TIMING_PAIRS			\
 	{ AFE440X_PRPCOUNT,	39999	},	\
 	{ AFE440X_LED2LEDSTC,	0	},	\
 	{ AFE440X_LED2LEDENDC,	398	},	\
 	{ AFE440X_LED2STC,	80	},	\
 	{ AFE440X_LED2ENDC,	398	},	\
 	{ AFE440X_ADCRSTSTCT0,	5600	},	\
 	{ AFE440X_ADCRSTENDCT0,	5606	},	\
 	{ AFE440X_LED2CONVST,	5607	},	\
 	{ AFE440X_LED2CONVEND,	6066	},	\
 	{ AFE4404_LED3LEDSTC,	400	},	\
 	{ AFE4404_LED3LEDENDC,	798	},	\
 	{ AFE440X_ALED2STC,	480	},	\
 	{ AFE440X_ALED2ENDC,	798	},	\
 	{ AFE440X_ADCRSTSTCT1,	6068	},	\
 	{ AFE440X_ADCRSTENDCT1,	6074	},	\
 	{ AFE440X_ALED2CONVST,	6075	},	\
 	{ AFE440X_ALED2CONVEND,	6534	},	\
 	{ AFE440X_LED1LEDSTC,	800	},	\
 	{ AFE440X_LED1LEDENDC,	1198	},	\
 	{ AFE440X_LED1STC,	880	},	\
 	{ AFE440X_LED1ENDC,	1198	},	\
 	{ AFE440X_ADCRSTSTCT2,	6536	},	\
 	{ AFE440X_ADCRSTENDCT2,	6542	},	\
 	{ AFE440X_LED1CONVST,	6543	},	\
 	{ AFE440X_LED1CONVEND,	7003	},	\
 	{ AFE440X_ALED1STC,	1280	},	\
 	{ AFE440X_ALED1ENDC,	1598	},	\
 	{ AFE440X_ADCRSTSTCT3,	7005	},	\
 	{ AFE440X_ADCRSTENDCT3,	7011	},	\
 	{ AFE440X_ALED1CONVST,	7012	},	\
 	{ AFE440X_ALED1CONVEND,	7471	},	\
 	{ AFE440X_PDNCYCLESTC,	7671	},	\
 	{ AFE440X_PDNCYCLEENDC,	39199	}

 static const struct reg_sequence afe4404_reg_sequences[] = {
 	AFE4404_TIMING_PAIRS,
 	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
 	{ AFE4404_TIA_GAIN_SEP, AFE440X_TIAGAIN_ENSEPGAIN },
 	{ AFE440X_CONTROL2, AFE440X_CONTROL2_OSC_ENABLE	},
 };

 static const struct regmap_range afe4404_yes_ranges[] = {
 	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
 	regmap_reg_range(AFE4404_AVG_LED2_ALED2VAL, AFE4404_AVG_LED1_ALED1VAL),
 };

 static const struct regmap_access_table afe4404_volatile_table = {
 	.yes_ranges = afe4404_yes_ranges,
 	.n_yes_ranges = ARRAY_SIZE(afe4404_yes_ranges),
 };

 static const struct regmap_config afe4404_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 24,

 	.max_register = AFE4404_AVG_LED1_ALED1VAL,
 	.cache_type = REGCACHE_RBTREE,
 	.volatile_table = &afe4404_volatile_table,
 };

 static const struct of_device_id afe4404_of_match[] = {
 	{ .compatible = "ti,afe4404", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, afe4404_of_match);

 static int __maybe_unused afe4404_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	int ret;

 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 				 AFE440X_CONTROL2_PDN_AFE,
 				 AFE440X_CONTROL2_PDN_AFE);
 	if (ret)
 		return ret;

 	ret = regulator_disable(afe->regulator);
 	if (ret) {
 		dev_err(dev, "Unable to disable regulator\n");
 		return ret;
 	}

 	return 0;
 }

 static int __maybe_unused afe4404_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	int ret;

 	ret = regulator_enable(afe->regulator);
 	if (ret) {
 		dev_err(dev, "Unable to enable regulator\n");
 		return ret;
 	}

 	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
 				 AFE440X_CONTROL2_PDN_AFE, 0);
 	if (ret)
 		return ret;

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(afe4404_pm_ops, afe4404_suspend, afe4404_resume);

 static int afe4404_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct iio_dev *indio_dev;
 	struct afe4404_data *afe;
 	int i, ret;

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*afe));
 	if (!indio_dev)
 		return -ENOMEM;

 	afe = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);

 	afe->dev = &client->dev;
 	afe->irq = client->irq;

 	afe->regmap = devm_regmap_init_i2c(client, &afe4404_regmap_config);
 	if (IS_ERR(afe->regmap)) {
 		dev_err(afe->dev, "Unable to allocate register map\n");
 		return PTR_ERR(afe->regmap);
 	}

 	for (i = 0; i < F_MAX_FIELDS; i++) {
 		afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
 							 afe4404_reg_fields[i]);
 		if (IS_ERR(afe->fields[i])) {
 			dev_err(afe->dev, "Unable to allocate regmap fields\n");
 			return PTR_ERR(afe->fields[i]);
 		}
 	}

 	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
 	if (IS_ERR(afe->regulator)) {
 		dev_err(afe->dev, "Unable to get regulator\n");
 		return PTR_ERR(afe->regulator);
 	}
 	ret = regulator_enable(afe->regulator);
 	if (ret) {
 		dev_err(afe->dev, "Unable to enable regulator\n");
 		return ret;
 	}

 	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
 			   AFE440X_CONTROL0_SW_RESET);
 	if (ret) {
 		dev_err(afe->dev, "Unable to reset device\n");
 		goto disable_reg;
 	}

 	ret = regmap_multi_reg_write(afe->regmap, afe4404_reg_sequences,
 				     ARRAY_SIZE(afe4404_reg_sequences));
 	if (ret) {
 		dev_err(afe->dev, "Unable to set register defaults\n");
 		goto disable_reg;
 	}

 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->dev.parent = afe->dev;
 	indio_dev->channels = afe4404_channels;
 	indio_dev->num_channels = ARRAY_SIZE(afe4404_channels);
 	indio_dev->name = AFE4404_DRIVER_NAME;
 	indio_dev->info = &afe4404_iio_info;

 	if (afe->irq > 0) {
 		afe->trig = devm_iio_trigger_alloc(afe->dev,
 						   "%s-dev%d",
 						   indio_dev->name,
 						   indio_dev->id);
 		if (!afe->trig) {
 			dev_err(afe->dev, "Unable to allocate IIO trigger\n");
 			ret = -ENOMEM;
 			goto disable_reg;
 		}

 		iio_trigger_set_drvdata(afe->trig, indio_dev);

 		afe->trig->ops = &afe4404_trigger_ops;
 		afe->trig->dev.parent = afe->dev;

 		ret = iio_trigger_register(afe->trig);
 		if (ret) {
 			dev_err(afe->dev, "Unable to register IIO trigger\n");
 			goto disable_reg;
 		}

 		ret = devm_request_threaded_irq(afe->dev, afe->irq,
 						iio_trigger_generic_data_rdy_poll,
 						NULL, IRQF_ONESHOT,
 						AFE4404_DRIVER_NAME,
 						afe->trig);
 		if (ret) {
 			dev_err(afe->dev, "Unable to request IRQ\n");
 			goto disable_reg;
 		}
 	}

 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 					 afe4404_trigger_handler, NULL);
 	if (ret) {
 		dev_err(afe->dev, "Unable to setup buffer\n");
 		goto unregister_trigger;
 	}

 	ret = iio_device_register(indio_dev);
 	if (ret) {
 		dev_err(afe->dev, "Unable to register IIO device\n");
 		goto unregister_triggered_buffer;
 	}

 	return 0;

 unregister_triggered_buffer:
 	iio_triggered_buffer_cleanup(indio_dev);
 unregister_trigger:
 	if (afe->irq > 0)
 		iio_trigger_unregister(afe->trig);
 disable_reg:
 	regulator_disable(afe->regulator);

 	return ret;
 }

 static int afe4404_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
 	struct afe4404_data *afe = iio_priv(indio_dev);
 	int ret;

 	iio_device_unregister(indio_dev);

 	iio_triggered_buffer_cleanup(indio_dev);

 	if (afe->irq > 0)
 		iio_trigger_unregister(afe->trig);

 	ret = regulator_disable(afe->regulator);
 	if (ret) {
 		dev_err(afe->dev, "Unable to disable regulator\n");
 		return ret;
 	}

 	return 0;
 }

 static const struct i2c_device_id afe4404_ids[] = {
 	{ "afe4404", 0 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(i2c, afe4404_ids);

 static struct i2c_driver afe4404_i2c_driver = {
 	.driver = {
 		.name = AFE4404_DRIVER_NAME,
 		.of_match_table = afe4404_of_match,
 		.pm = &afe4404_pm_ops,
 	},
 	.probe = afe4404_probe,
 	.remove = afe4404_remove,
 	.id_table = afe4404_ids,
 };
 module_i2c_driver(afe4404_i2c_driver);

 MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
 MODULE_DESCRIPTION("TI AFE4404 Heart Rate Monitor and Pulse Oximeter AFE");
 MODULE_LICENSE("GPL v2");
	/*
	* AFE4404 Heart Rate Monitors and Low-Cost Pulse Oximeters
	*
	* Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/
	* Andrew F. Davis <afd@ti.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.
	*/

	#include <linux/device.h>
	#include <linux/err.h>
	#include <linux/interrupt.h>
	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/regmap.h>
	#include <linux/sysfs.h>
	#include <linux/regulator/consumer.h>

	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/trigger.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/trigger_consumer.h>

	#include "afe440x.h"

	#define AFE4404_DRIVER_NAME "afe4404"

	/* AFE4404 registers */
	#define AFE4404_TIA_GAIN_SEP 0x20
	#define AFE4404_TIA_GAIN 0x21
	#define AFE4404_PROG_TG_STC 0x34
	#define AFE4404_PROG_TG_ENDC 0x35
	#define AFE4404_LED3LEDSTC 0x36
	#define AFE4404_LED3LEDENDC 0x37
	#define AFE4404_CLKDIV_PRF 0x39
	#define AFE4404_OFFDAC 0x3a
	#define AFE4404_DEC 0x3d
	#define AFE4404_AVG_LED2_ALED2VAL 0x3f
	#define AFE4404_AVG_LED1_ALED1VAL 0x40

	/* AFE4404 CONTROL2 register fields */
	#define AFE440X_CONTROL2_OSC_ENABLE BIT(9)

	enum afe4404_fields {
	/* Gains */
	F_TIA_GAIN_SEP, F_TIA_CF_SEP,
	F_TIA_GAIN, TIA_CF,

	/* LED Current */
	F_ILED1, F_ILED2, F_ILED3,

	/* Offset DAC */
	F_OFFDAC_AMB2, F_OFFDAC_LED1, F_OFFDAC_AMB1, F_OFFDAC_LED2,

	/* sentinel */
	F_MAX_FIELDS
	};

	static const struct reg_field afe4404_reg_fields[] = {
	/* Gains */
	[F_TIA_GAIN_SEP] = REG_FIELD(AFE4404_TIA_GAIN_SEP, 0, 2),
	[F_TIA_CF_SEP] = REG_FIELD(AFE4404_TIA_GAIN_SEP, 3, 5),
	[F_TIA_GAIN] = REG_FIELD(AFE4404_TIA_GAIN, 0, 2),
	[TIA_CF] = REG_FIELD(AFE4404_TIA_GAIN, 3, 5),
	/* LED Current */
	[F_ILED1] = REG_FIELD(AFE440X_LEDCNTRL, 0, 5),
	[F_ILED2] = REG_FIELD(AFE440X_LEDCNTRL, 6, 11),
	[F_ILED3] = REG_FIELD(AFE440X_LEDCNTRL, 12, 17),
	/* Offset DAC */
	[F_OFFDAC_AMB2] = REG_FIELD(AFE4404_OFFDAC, 0, 4),
	[F_OFFDAC_LED1] = REG_FIELD(AFE4404_OFFDAC, 5, 9),
	[F_OFFDAC_AMB1] = REG_FIELD(AFE4404_OFFDAC, 10, 14),
	[F_OFFDAC_LED2] = REG_FIELD(AFE4404_OFFDAC, 15, 19),
	};

	/**
	* struct afe4404_data - AFE4404 device instance data
	* @dev: Device structure
	* @regmap: Register map of the device
	* @fields: Register fields of the device
	* @regulator: Pointer to the regulator for the IC
	* @trig: IIO trigger for this device
	* @irq: ADC_RDY line interrupt number
	*/
	struct afe4404_data {
	struct device *dev;
	struct regmap *regmap;
	struct regmap_field *fields[F_MAX_FIELDS];
	struct regulator *regulator;
	struct iio_trigger *trig;
	int irq;
	};

	enum afe4404_chan_id {
	LED2 = 1,
	ALED2,
	LED1,
	ALED1,
	LED2_ALED2,
	LED1_ALED1,
	};

	static const unsigned int afe4404_channel_values[] = {
	[LED2] = AFE440X_LED2VAL,
	[ALED2] = AFE440X_ALED2VAL,
	[LED1] = AFE440X_LED1VAL,
	[ALED1] = AFE440X_ALED1VAL,
	[LED2_ALED2] = AFE440X_LED2_ALED2VAL,
	[LED1_ALED1] = AFE440X_LED1_ALED1VAL,
	};

	static const unsigned int afe4404_channel_leds[] = {
	[LED2] = F_ILED2,
	[ALED2] = F_ILED3,
	[LED1] = F_ILED1,
	};

	static const unsigned int afe4404_channel_offdacs[] = {
	[LED2] = F_OFFDAC_LED2,
	[ALED2] = F_OFFDAC_AMB2,
	[LED1] = F_OFFDAC_LED1,
	[ALED1] = F_OFFDAC_AMB1,
	};

	static const struct iio_chan_spec afe4404_channels[] = {
	/* ADC values */
	AFE440X_INTENSITY_CHAN(LED2, BIT(IIO_CHAN_INFO_OFFSET)),
	AFE440X_INTENSITY_CHAN(ALED2, BIT(IIO_CHAN_INFO_OFFSET)),
	AFE440X_INTENSITY_CHAN(LED1, BIT(IIO_CHAN_INFO_OFFSET)),
	AFE440X_INTENSITY_CHAN(ALED1, BIT(IIO_CHAN_INFO_OFFSET)),
	AFE440X_INTENSITY_CHAN(LED2_ALED2, 0),
	AFE440X_INTENSITY_CHAN(LED1_ALED1, 0),
	/* LED current */
	AFE440X_CURRENT_CHAN(LED2),
	AFE440X_CURRENT_CHAN(ALED2),
	AFE440X_CURRENT_CHAN(LED1),
	};

	static const struct afe440x_val_table afe4404_res_table[] = {
	{ .integer = 500000, .fract = 0 },
	{ .integer = 250000, .fract = 0 },
	{ .integer = 100000, .fract = 0 },
	{ .integer = 50000, .fract = 0 },
	{ .integer = 25000, .fract = 0 },
	{ .integer = 10000, .fract = 0 },
	{ .integer = 1000000, .fract = 0 },
	{ .integer = 2000000, .fract = 0 },
	};
	AFE440X_TABLE_ATTR(in_intensity_resistance_available, afe4404_res_table);

	static const struct afe440x_val_table afe4404_cap_table[] = {
	{ .integer = 0, .fract = 5000 },
	{ .integer = 0, .fract = 2500 },
	{ .integer = 0, .fract = 10000 },
	{ .integer = 0, .fract = 7500 },
	{ .integer = 0, .fract = 20000 },
	{ .integer = 0, .fract = 17500 },
	{ .integer = 0, .fract = 25000 },
	{ .integer = 0, .fract = 22500 },
	};
	AFE440X_TABLE_ATTR(in_intensity_capacitance_available, afe4404_cap_table);

	static ssize_t afe440x_show_register(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct afe4404_data *afe = iio_priv(indio_dev);
	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
	unsigned int reg_val;
	int vals[2];
	int ret;

	ret = regmap_field_read(afe->fields[afe440x_attr->field], &reg_val);
	if (ret)
	return ret;

	if (reg_val >= afe440x_attr->table_size)
	return -EINVAL;

	vals[0] = afe440x_attr->val_table[reg_val].integer;
	vals[1] = afe440x_attr->val_table[reg_val].fract;

	return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO, 2, vals);
	}

	static ssize_t afe440x_store_register(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct afe4404_data *afe = iio_priv(indio_dev);
	struct afe440x_attr *afe440x_attr = to_afe440x_attr(attr);
	int val, integer, fract, ret;

	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
	if (ret)
	return ret;

	for (val = 0; val < afe440x_attr->table_size; val++)
	if (afe440x_attr->val_table[val].integer == integer &&
	afe440x_attr->val_table[val].fract == fract)
	break;
	if (val == afe440x_attr->table_size)
	return -EINVAL;

	ret = regmap_field_write(afe->fields[afe440x_attr->field], val);
	if (ret)
	return ret;

	return count;
	}

	static AFE440X_ATTR(in_intensity1_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
	static AFE440X_ATTR(in_intensity1_capacitance, F_TIA_CF_SEP, afe4404_cap_table);

	static AFE440X_ATTR(in_intensity2_resistance, F_TIA_GAIN_SEP, afe4404_res_table);
	static AFE440X_ATTR(in_intensity2_capacitance, F_TIA_CF_SEP, afe4404_cap_table);

	static AFE440X_ATTR(in_intensity3_resistance, F_TIA_GAIN, afe4404_res_table);
	static AFE440X_ATTR(in_intensity3_capacitance, TIA_CF, afe4404_cap_table);

	static AFE440X_ATTR(in_intensity4_resistance, F_TIA_GAIN, afe4404_res_table);
	static AFE440X_ATTR(in_intensity4_capacitance, TIA_CF, afe4404_cap_table);

	static struct attribute *afe440x_attributes[] = {
	&dev_attr_in_intensity_resistance_available.attr,
	&dev_attr_in_intensity_capacitance_available.attr,
	&afe440x_attr_in_intensity1_resistance.dev_attr.attr,
	&afe440x_attr_in_intensity1_capacitance.dev_attr.attr,
	&afe440x_attr_in_intensity2_resistance.dev_attr.attr,
	&afe440x_attr_in_intensity2_capacitance.dev_attr.attr,
	&afe440x_attr_in_intensity3_resistance.dev_attr.attr,
	&afe440x_attr_in_intensity3_capacitance.dev_attr.attr,
	&afe440x_attr_in_intensity4_resistance.dev_attr.attr,
	&afe440x_attr_in_intensity4_capacitance.dev_attr.attr,
	NULL
	};

	static const struct attribute_group afe440x_attribute_group = {
	.attrs = afe440x_attributes
	};

	static int afe4404_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct afe4404_data *afe = iio_priv(indio_dev);
	unsigned int value_reg = afe4404_channel_values[chan->address];
	unsigned int led_field = afe4404_channel_leds[chan->address];
	unsigned int offdac_field = afe4404_channel_offdacs[chan->address];
	int ret;

	switch (chan->type) {
	case IIO_INTENSITY:
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	ret = regmap_read(afe->regmap, value_reg, val);
	if (ret)
	return ret;
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_OFFSET:
	ret = regmap_field_read(afe->fields[offdac_field], val);
	if (ret)
	return ret;
	return IIO_VAL_INT;
	}
	break;
	case IIO_CURRENT:
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	ret = regmap_field_read(afe->fields[led_field], val);
	if (ret)
	return ret;
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	*val = 0;
	*val2 = 800000;
	return IIO_VAL_INT_PLUS_MICRO;
	}
	break;
	default:
	break;
	}

	return -EINVAL;
	}

	static int afe4404_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct afe4404_data *afe = iio_priv(indio_dev);
	unsigned int led_field = afe4404_channel_leds[chan->address];
	unsigned int offdac_field = afe4404_channel_offdacs[chan->address];

	switch (chan->type) {
	case IIO_INTENSITY:
	switch (mask) {
	case IIO_CHAN_INFO_OFFSET:
	return regmap_field_write(afe->fields[offdac_field], val);
	}
	break;
	case IIO_CURRENT:
	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	return regmap_field_write(afe->fields[led_field], val);
	}
	break;
	default:
	break;
	}

	return -EINVAL;
	}

	static const struct iio_info afe4404_iio_info = {
	.attrs = &afe440x_attribute_group,
	.read_raw = afe4404_read_raw,
	.write_raw = afe4404_write_raw,
	.driver_module = THIS_MODULE,
	};

	static irqreturn_t afe4404_trigger_handler(int irq, void *private)
	{
	struct iio_poll_func *pf = private;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct afe4404_data *afe = iio_priv(indio_dev);
	int ret, bit, i = 0;
	s32 buffer[10];

	for_each_set_bit(bit, indio_dev->active_scan_mask,
	indio_dev->masklength) {
	ret = regmap_read(afe->regmap, afe4404_channel_values[bit],
	&buffer[i++]);
	if (ret)
	goto err;
	}

	iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
	err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static const struct iio_trigger_ops afe4404_trigger_ops = {
	.owner = THIS_MODULE,
	};

	/* Default timings from data-sheet */
	#define AFE4404_TIMING_PAIRS \
	{ AFE440X_PRPCOUNT, 39999 }, \
	{ AFE440X_LED2LEDSTC, 0 }, \
	{ AFE440X_LED2LEDENDC, 398 }, \
	{ AFE440X_LED2STC, 80 }, \
	{ AFE440X_LED2ENDC, 398 }, \
	{ AFE440X_ADCRSTSTCT0, 5600 }, \
	{ AFE440X_ADCRSTENDCT0, 5606 }, \
	{ AFE440X_LED2CONVST, 5607 }, \
	{ AFE440X_LED2CONVEND, 6066 }, \
	{ AFE4404_LED3LEDSTC, 400 }, \
	{ AFE4404_LED3LEDENDC, 798 }, \
	{ AFE440X_ALED2STC, 480 }, \
	{ AFE440X_ALED2ENDC, 798 }, \
	{ AFE440X_ADCRSTSTCT1, 6068 }, \
	{ AFE440X_ADCRSTENDCT1, 6074 }, \
	{ AFE440X_ALED2CONVST, 6075 }, \
	{ AFE440X_ALED2CONVEND, 6534 }, \
	{ AFE440X_LED1LEDSTC, 800 }, \
	{ AFE440X_LED1LEDENDC, 1198 }, \
	{ AFE440X_LED1STC, 880 }, \
	{ AFE440X_LED1ENDC, 1198 }, \
	{ AFE440X_ADCRSTSTCT2, 6536 }, \
	{ AFE440X_ADCRSTENDCT2, 6542 }, \
	{ AFE440X_LED1CONVST, 6543 }, \
	{ AFE440X_LED1CONVEND, 7003 }, \
	{ AFE440X_ALED1STC, 1280 }, \
	{ AFE440X_ALED1ENDC, 1598 }, \
	{ AFE440X_ADCRSTSTCT3, 7005 }, \
	{ AFE440X_ADCRSTENDCT3, 7011 }, \
	{ AFE440X_ALED1CONVST, 7012 }, \
	{ AFE440X_ALED1CONVEND, 7471 }, \
	{ AFE440X_PDNCYCLESTC, 7671 }, \
	{ AFE440X_PDNCYCLEENDC, 39199 }

	static const struct reg_sequence afe4404_reg_sequences[] = {
	AFE4404_TIMING_PAIRS,
	{ AFE440X_CONTROL1, AFE440X_CONTROL1_TIMEREN },
	{ AFE4404_TIA_GAIN_SEP, AFE440X_TIAGAIN_ENSEPGAIN },
	{ AFE440X_CONTROL2, AFE440X_CONTROL2_OSC_ENABLE },
	};

	static const struct regmap_range afe4404_yes_ranges[] = {
	regmap_reg_range(AFE440X_LED2VAL, AFE440X_LED1_ALED1VAL),
	regmap_reg_range(AFE4404_AVG_LED2_ALED2VAL, AFE4404_AVG_LED1_ALED1VAL),
	};

	static const struct regmap_access_table afe4404_volatile_table = {
	.yes_ranges = afe4404_yes_ranges,
	.n_yes_ranges = ARRAY_SIZE(afe4404_yes_ranges),
	};

	static const struct regmap_config afe4404_regmap_config = {
	.reg_bits = 8,
	.val_bits = 24,

	.max_register = AFE4404_AVG_LED1_ALED1VAL,
	.cache_type = REGCACHE_RBTREE,
	.volatile_table = &afe4404_volatile_table,
	};

	static const struct of_device_id afe4404_of_match[] = {
	{ .compatible = "ti,afe4404", },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(of, afe4404_of_match);

	static int __maybe_unused afe4404_suspend(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct afe4404_data *afe = iio_priv(indio_dev);
	int ret;

	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
	AFE440X_CONTROL2_PDN_AFE,
	AFE440X_CONTROL2_PDN_AFE);
	if (ret)
	return ret;

	ret = regulator_disable(afe->regulator);
	if (ret) {
	dev_err(dev, "Unable to disable regulator\n");
	return ret;
	}

	return 0;
	}

	static int __maybe_unused afe4404_resume(struct device *dev)
	{
	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
	struct afe4404_data *afe = iio_priv(indio_dev);
	int ret;

	ret = regulator_enable(afe->regulator);
	if (ret) {
	dev_err(dev, "Unable to enable regulator\n");
	return ret;
	}

	ret = regmap_update_bits(afe->regmap, AFE440X_CONTROL2,
	AFE440X_CONTROL2_PDN_AFE, 0);
	if (ret)
	return ret;

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(afe4404_pm_ops, afe4404_suspend, afe4404_resume);

	static int afe4404_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct iio_dev *indio_dev;
	struct afe4404_data *afe;
	int i, ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*afe));
	if (!indio_dev)
	return -ENOMEM;

	afe = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);

	afe->dev = &client->dev;
	afe->irq = client->irq;

	afe->regmap = devm_regmap_init_i2c(client, &afe4404_regmap_config);
	if (IS_ERR(afe->regmap)) {
	dev_err(afe->dev, "Unable to allocate register map\n");
	return PTR_ERR(afe->regmap);
	}

	for (i = 0; i < F_MAX_FIELDS; i++) {
	afe->fields[i] = devm_regmap_field_alloc(afe->dev, afe->regmap,
	afe4404_reg_fields[i]);
	if (IS_ERR(afe->fields[i])) {
	dev_err(afe->dev, "Unable to allocate regmap fields\n");
	return PTR_ERR(afe->fields[i]);
	}
	}

	afe->regulator = devm_regulator_get(afe->dev, "tx_sup");
	if (IS_ERR(afe->regulator)) {
	dev_err(afe->dev, "Unable to get regulator\n");
	return PTR_ERR(afe->regulator);
	}
	ret = regulator_enable(afe->regulator);
	if (ret) {
	dev_err(afe->dev, "Unable to enable regulator\n");
	return ret;
	}

	ret = regmap_write(afe->regmap, AFE440X_CONTROL0,
	AFE440X_CONTROL0_SW_RESET);
	if (ret) {
	dev_err(afe->dev, "Unable to reset device\n");
	goto disable_reg;
	}

	ret = regmap_multi_reg_write(afe->regmap, afe4404_reg_sequences,
	ARRAY_SIZE(afe4404_reg_sequences));
	if (ret) {
	dev_err(afe->dev, "Unable to set register defaults\n");
	goto disable_reg;
	}

	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->dev.parent = afe->dev;
	indio_dev->channels = afe4404_channels;
	indio_dev->num_channels = ARRAY_SIZE(afe4404_channels);
	indio_dev->name = AFE4404_DRIVER_NAME;
	indio_dev->info = &afe4404_iio_info;

	if (afe->irq > 0) {
	afe->trig = devm_iio_trigger_alloc(afe->dev,
	"%s-dev%d",
	indio_dev->name,
	indio_dev->id);
	if (!afe->trig) {
	dev_err(afe->dev, "Unable to allocate IIO trigger\n");
	ret = -ENOMEM;
	goto disable_reg;
	}

	iio_trigger_set_drvdata(afe->trig, indio_dev);

	afe->trig->ops = &afe4404_trigger_ops;
	afe->trig->dev.parent = afe->dev;

	ret = iio_trigger_register(afe->trig);
	if (ret) {
	dev_err(afe->dev, "Unable to register IIO trigger\n");
	goto disable_reg;
	}

	ret = devm_request_threaded_irq(afe->dev, afe->irq,
	iio_trigger_generic_data_rdy_poll,
	NULL, IRQF_ONESHOT,
	AFE4404_DRIVER_NAME,
	afe->trig);
	if (ret) {
	dev_err(afe->dev, "Unable to request IRQ\n");
	goto disable_reg;
	}
	}

	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
	afe4404_trigger_handler, NULL);
	if (ret) {
	dev_err(afe->dev, "Unable to setup buffer\n");
	goto unregister_trigger;
	}

	ret = iio_device_register(indio_dev);
	if (ret) {
	dev_err(afe->dev, "Unable to register IIO device\n");
	goto unregister_triggered_buffer;
	}

	return 0;

	unregister_triggered_buffer:
	iio_triggered_buffer_cleanup(indio_dev);
	unregister_trigger:
	if (afe->irq > 0)
	iio_trigger_unregister(afe->trig);
	disable_reg:
	regulator_disable(afe->regulator);

	return ret;
	}

	static int afe4404_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct afe4404_data *afe = iio_priv(indio_dev);
	int ret;

	iio_device_unregister(indio_dev);

	iio_triggered_buffer_cleanup(indio_dev);

	if (afe->irq > 0)
	iio_trigger_unregister(afe->trig);

	ret = regulator_disable(afe->regulator);
	if (ret) {
	dev_err(afe->dev, "Unable to disable regulator\n");
	return ret;
	}

	return 0;
	}

	static const struct i2c_device_id afe4404_ids[] = {
	{ "afe4404", 0 },
	{ /* sentinel */ }
	};
	MODULE_DEVICE_TABLE(i2c, afe4404_ids);

	static struct i2c_driver afe4404_i2c_driver = {
	.driver = {
	.name = AFE4404_DRIVER_NAME,
	.of_match_table = afe4404_of_match,
	.pm = &afe4404_pm_ops,
	},
	.probe = afe4404_probe,
	.remove = afe4404_remove,
	.id_table = afe4404_ids,
	};
	module_i2c_driver(afe4404_i2c_driver);

	MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
	MODULE_DESCRIPTION("TI AFE4404 Heart Rate Monitor and Pulse Oximeter AFE");
	MODULE_LICENSE("GPL v2");