[linux-block.git] / drivers / iio / health / max30100.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor
 *
 * Copyright (C) 2015, 2018
 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
 *
 * TODO: enable pulse length controls via device tree properties
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/kfifo_buf.h>

#define MAX30100_REGMAP_NAME	"max30100_regmap"
#define MAX30100_DRV_NAME	"max30100"

#define MAX30100_REG_INT_STATUS			0x00
#define MAX30100_REG_INT_STATUS_PWR_RDY		BIT(0)
#define MAX30100_REG_INT_STATUS_SPO2_RDY	BIT(4)
#define MAX30100_REG_INT_STATUS_HR_RDY		BIT(5)
#define MAX30100_REG_INT_STATUS_FIFO_RDY	BIT(7)

#define MAX30100_REG_INT_ENABLE			0x01
#define MAX30100_REG_INT_ENABLE_SPO2_EN		BIT(0)
#define MAX30100_REG_INT_ENABLE_HR_EN		BIT(1)
#define MAX30100_REG_INT_ENABLE_FIFO_EN		BIT(3)
#define MAX30100_REG_INT_ENABLE_MASK		0xf0
#define MAX30100_REG_INT_ENABLE_MASK_SHIFT	4

#define MAX30100_REG_FIFO_WR_PTR		0x02
#define MAX30100_REG_FIFO_OVR_CTR		0x03
#define MAX30100_REG_FIFO_RD_PTR		0x04
#define MAX30100_REG_FIFO_DATA			0x05
#define MAX30100_REG_FIFO_DATA_ENTRY_COUNT	16
#define MAX30100_REG_FIFO_DATA_ENTRY_LEN	4

#define MAX30100_REG_MODE_CONFIG		0x06
#define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN	BIT(0)
#define MAX30100_REG_MODE_CONFIG_MODE_HR_EN	BIT(1)
#define MAX30100_REG_MODE_CONFIG_MODE_MASK	0x03
#define MAX30100_REG_MODE_CONFIG_TEMP_EN	BIT(3)
#define MAX30100_REG_MODE_CONFIG_PWR		BIT(7)

#define MAX30100_REG_SPO2_CONFIG		0x07
#define MAX30100_REG_SPO2_CONFIG_100HZ		BIT(2)
#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN	BIT(6)
#define MAX30100_REG_SPO2_CONFIG_1600US		0x3

#define MAX30100_REG_LED_CONFIG			0x09
#define MAX30100_REG_LED_CONFIG_LED_MASK	0x0f
#define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT	4

#define MAX30100_REG_LED_CONFIG_24MA		0x07
#define MAX30100_REG_LED_CONFIG_50MA		0x0f

#define MAX30100_REG_TEMP_INTEGER		0x16
#define MAX30100_REG_TEMP_FRACTION		0x17

struct max30100_data {
	struct i2c_client *client;
	struct iio_dev *indio_dev;
	struct mutex lock;
	struct regmap *regmap;

	__be16 buffer[2]; /* 2 16-bit channels */
};

static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case MAX30100_REG_INT_STATUS:
	case MAX30100_REG_MODE_CONFIG:
	case MAX30100_REG_FIFO_WR_PTR:
	case MAX30100_REG_FIFO_OVR_CTR:
	case MAX30100_REG_FIFO_RD_PTR:
	case MAX30100_REG_FIFO_DATA:
	case MAX30100_REG_TEMP_INTEGER:
	case MAX30100_REG_TEMP_FRACTION:
		return true;
	default:
		return false;
	}
}

static const struct regmap_config max30100_regmap_config = {
	.name = MAX30100_REGMAP_NAME,

	.reg_bits = 8,
	.val_bits = 8,

	.max_register = MAX30100_REG_TEMP_FRACTION,
	.cache_type = REGCACHE_FLAT,

	.volatile_reg = max30100_is_volatile_reg,
};

static const unsigned int max30100_led_current_mapping[] = {
	4400, 7600, 11000, 14200, 17400,
	20800, 24000, 27100, 30600, 33800,
	37000, 40200, 43600, 46800, 50000
};

static const unsigned long max30100_scan_masks[] = {0x3, 0};

static const struct iio_chan_spec max30100_channels[] = {
	{
		.type = IIO_INTENSITY,
		.channel2 = IIO_MOD_LIGHT_IR,
		.modified = 1,

		.scan_index = 0,
		.scan_type = {
			.sign = 'u',
			.realbits = 16,
			.storagebits = 16,
			.endianness = IIO_BE,
		},
	},
	{
		.type = IIO_INTENSITY,
		.channel2 = IIO_MOD_LIGHT_RED,
		.modified = 1,

		.scan_index = 1,
		.scan_type = {
			.sign = 'u',
			.realbits = 16,
			.storagebits = 16,
			.endianness = IIO_BE,
		},
	},
	{
		.type = IIO_TEMP,
		.info_mask_separate =
			BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
		.scan_index = -1,
	},
};

static int max30100_set_powermode(struct max30100_data *data, bool state)
{
	return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
				  MAX30100_REG_MODE_CONFIG_PWR,
				  state ? 0 : MAX30100_REG_MODE_CONFIG_PWR);
}

static int max30100_clear_fifo(struct max30100_data *data)
{
	int ret;

	ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0);
	if (ret)
		return ret;

	ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0);
	if (ret)
		return ret;

	return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0);
}

static int max30100_buffer_postenable(struct iio_dev *indio_dev)
{
	struct max30100_data *data = iio_priv(indio_dev);
	int ret;

	ret = max30100_set_powermode(data, true);
	if (ret)
		return ret;

	return max30100_clear_fifo(data);
}

static int max30100_buffer_predisable(struct iio_dev *indio_dev)
{
	struct max30100_data *data = iio_priv(indio_dev);

	return max30100_set_powermode(data, false);
}

static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = {
	.postenable = max30100_buffer_postenable,
	.predisable = max30100_buffer_predisable,
};

static inline int max30100_fifo_count(struct max30100_data *data)
{
	unsigned int val;
	int ret;

	ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val);
	if (ret)
		return ret;

	/* FIFO is almost full */
	if (val & MAX30100_REG_INT_STATUS_FIFO_RDY)
		return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1;

	return 0;
}

static int max30100_read_measurement(struct max30100_data *data)
{
	int ret;

	ret = i2c_smbus_read_i2c_block_data(data->client,
					    MAX30100_REG_FIFO_DATA,
					    MAX30100_REG_FIFO_DATA_ENTRY_LEN,
					    (u8 *) &data->buffer);

	return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret;
}

static irqreturn_t max30100_interrupt_handler(int irq, void *private)
{
	struct iio_dev *indio_dev = private;
	struct max30100_data *data = iio_priv(indio_dev);
	int ret, cnt = 0;

	mutex_lock(&data->lock);

	while (cnt || (cnt = max30100_fifo_count(data)) > 0) {
		ret = max30100_read_measurement(data);
		if (ret)
			break;

		iio_push_to_buffers(data->indio_dev, data->buffer);
		cnt--;
	}

	mutex_unlock(&data->lock);

	return IRQ_HANDLED;
}

static int max30100_get_current_idx(unsigned int val, int *reg)
{
	int idx;

	/* LED turned off */
	if (val == 0) {
		*reg = 0;
		return 0;
	}

	for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) {
		if (max30100_led_current_mapping[idx] == val) {
			*reg = idx + 1;
			return 0;
		}
	}

	return -EINVAL;
}

static int max30100_led_init(struct max30100_data *data)
{
	struct device *dev = &data->client->dev;
	struct device_node *np = dev->of_node;
	unsigned int val[2];
	int reg, ret;

	ret = of_property_read_u32_array(np, "maxim,led-current-microamp",
					(unsigned int *) &val, 2);
	if (ret) {
		/* Default to 24 mA RED LED, 50 mA IR LED */
		reg = (MAX30100_REG_LED_CONFIG_24MA <<
			MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) |
			MAX30100_REG_LED_CONFIG_50MA;
		dev_warn(dev, "no led-current-microamp set");

		return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg);
	}

	/* RED LED current */
	ret = max30100_get_current_idx(val[0], &reg);
	if (ret) {
		dev_err(dev, "invalid RED current setting %d", val[0]);
		return ret;
	}

	ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
		MAX30100_REG_LED_CONFIG_LED_MASK <<
		MAX30100_REG_LED_CONFIG_RED_LED_SHIFT,
		reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT);
	if (ret)
		return ret;

	/* IR LED current */
	ret = max30100_get_current_idx(val[1], &reg);
	if (ret) {
		dev_err(dev, "invalid IR current setting %d", val[1]);
		return ret;
	}

	return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
		MAX30100_REG_LED_CONFIG_LED_MASK, reg);
}

static int max30100_chip_init(struct max30100_data *data)
{
	int ret;

	/* setup LED current settings */
	ret = max30100_led_init(data);
	if (ret)
		return ret;

	/* enable hi-res SPO2 readings at 100Hz */
	ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG,
				 MAX30100_REG_SPO2_CONFIG_HI_RES_EN |
				 MAX30100_REG_SPO2_CONFIG_100HZ);
	if (ret)
		return ret;

	/* enable SPO2 mode */
	ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
				 MAX30100_REG_MODE_CONFIG_MODE_MASK,
				 MAX30100_REG_MODE_CONFIG_MODE_HR_EN |
				 MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN);
	if (ret)
		return ret;

	/* enable FIFO interrupt */
	return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE,
				 MAX30100_REG_INT_ENABLE_MASK,
				 MAX30100_REG_INT_ENABLE_FIFO_EN
				 << MAX30100_REG_INT_ENABLE_MASK_SHIFT);
}

static int max30100_read_temp(struct max30100_data *data, int *val)
{
	int ret;
	unsigned int reg;

	ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, &reg);
	if (ret < 0)
		return ret;
	*val = reg << 4;

	ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, &reg);
	if (ret < 0)
		return ret;

	*val |= reg & 0xf;
	*val = sign_extend32(*val, 11);

	return 0;
}

static int max30100_get_temp(struct max30100_data *data, int *val)
{
	int ret;

	/* start acquisition */
	ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
				 MAX30100_REG_MODE_CONFIG_TEMP_EN,
				 MAX30100_REG_MODE_CONFIG_TEMP_EN);
	if (ret)
		return ret;

	msleep(35);

	return max30100_read_temp(data, val);
}

static int max30100_read_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int *val, int *val2, long mask)
{
	struct max30100_data *data = iio_priv(indio_dev);
	int ret = -EINVAL;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		/*
		 * Temperature reading can only be acquired while engine
		 * is running
		 */
		mutex_lock(&indio_dev->mlock);

		if (!iio_buffer_enabled(indio_dev))
			ret = -EAGAIN;
		else {
			ret = max30100_get_temp(data, val);
			if (!ret)
				ret = IIO_VAL_INT;

		}

		mutex_unlock(&indio_dev->mlock);
		break;
	case IIO_CHAN_INFO_SCALE:
		*val = 1;  /* 0.0625 */
		*val2 = 16;
		ret = IIO_VAL_FRACTIONAL;
		break;
	}

	return ret;
}

static const struct iio_info max30100_info = {
	.read_raw = max30100_read_raw,
};

static int max30100_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct max30100_data *data;
	struct iio_buffer *buffer;
	struct iio_dev *indio_dev;
	int ret;

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

	buffer = devm_iio_kfifo_allocate(&client->dev);
	if (!buffer)
		return -ENOMEM;

	iio_device_attach_buffer(indio_dev, buffer);

	indio_dev->name = MAX30100_DRV_NAME;
	indio_dev->channels = max30100_channels;
	indio_dev->info = &max30100_info;
	indio_dev->num_channels = ARRAY_SIZE(max30100_channels);
	indio_dev->available_scan_masks = max30100_scan_masks;
	indio_dev->modes = (INDIO_BUFFER_SOFTWARE | INDIO_DIRECT_MODE);
	indio_dev->setup_ops = &max30100_buffer_setup_ops;
	indio_dev->dev.parent = &client->dev;

	data = iio_priv(indio_dev);
	data->indio_dev = indio_dev;
	data->client = client;

	mutex_init(&data->lock);
	i2c_set_clientdata(client, indio_dev);

	data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config);
	if (IS_ERR(data->regmap)) {
		dev_err(&client->dev, "regmap initialization failed.\n");
		return PTR_ERR(data->regmap);
	}
	max30100_set_powermode(data, false);

	ret = max30100_chip_init(data);
	if (ret)
		return ret;

	if (client->irq <= 0) {
		dev_err(&client->dev, "no valid irq defined\n");
		return -EINVAL;
	}
	ret = devm_request_threaded_irq(&client->dev, client->irq,
					NULL, max30100_interrupt_handler,
					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
					"max30100_irq", indio_dev);
	if (ret) {
		dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
		return ret;
	}

	return iio_device_register(indio_dev);
}

static int max30100_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct max30100_data *data = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	max30100_set_powermode(data, false);

	return 0;
}

static const struct i2c_device_id max30100_id[] = {
	{ "max30100", 0 },
	{}
};
MODULE_DEVICE_TABLE(i2c, max30100_id);

static const struct of_device_id max30100_dt_ids[] = {
	{ .compatible = "maxim,max30100" },
	{ }
};
MODULE_DEVICE_TABLE(of, max30100_dt_ids);

static struct i2c_driver max30100_driver = {
	.driver = {
		.name	= MAX30100_DRV_NAME,
		.of_match_table	= of_match_ptr(max30100_dt_ids),
	},
	.probe		= max30100_probe,
	.remove		= max30100_remove,
	.id_table	= max30100_id,
};
module_i2c_driver(max30100_driver);

MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor");
MODULE_LICENSE("GPL");
Commit	Line	Data
d6ad8058	1	// SPDX-License-Identifier: GPL-2.0+
4d33615d MR	2	/*
	3	* max30100.c - Support for MAX30100 heart rate and pulse oximeter sensor
	4	*
d6ad8058 MR	5	* Copyright (C) 2015, 2018
d6ad8058 MR	6	* Author: Matt Ranostay <matt.ranostay@konsulko.com>
4d33615d	7	*
b11a3460	8	* TODO: enable pulse length controls via device tree properties
4d33615d MR	9	*/
	10
	11	#include <linux/module.h>
	12	#include <linux/init.h>
	13	#include <linux/interrupt.h>
	14	#include <linux/delay.h>
	15	#include <linux/err.h>
	16	#include <linux/irq.h>
	17	#include <linux/i2c.h>
	18	#include <linux/mutex.h>
b11a3460	19	#include <linux/of.h>
4d33615d MR	20	#include <linux/regmap.h>
	21	#include <linux/iio/iio.h>
	22	#include <linux/iio/buffer.h>
	23	#include <linux/iio/kfifo_buf.h>
	24
	25	#define MAX30100_REGMAP_NAME "max30100_regmap"
	26	#define MAX30100_DRV_NAME "max30100"
	27
	28	#define MAX30100_REG_INT_STATUS 0x00
	29	#define MAX30100_REG_INT_STATUS_PWR_RDY BIT(0)
	30	#define MAX30100_REG_INT_STATUS_SPO2_RDY BIT(4)
	31	#define MAX30100_REG_INT_STATUS_HR_RDY BIT(5)
	32	#define MAX30100_REG_INT_STATUS_FIFO_RDY BIT(7)
	33
	34	#define MAX30100_REG_INT_ENABLE 0x01
	35	#define MAX30100_REG_INT_ENABLE_SPO2_EN BIT(0)
	36	#define MAX30100_REG_INT_ENABLE_HR_EN BIT(1)
	37	#define MAX30100_REG_INT_ENABLE_FIFO_EN BIT(3)
	38	#define MAX30100_REG_INT_ENABLE_MASK 0xf0
	39	#define MAX30100_REG_INT_ENABLE_MASK_SHIFT 4
	40
	41	#define MAX30100_REG_FIFO_WR_PTR 0x02
	42	#define MAX30100_REG_FIFO_OVR_CTR 0x03
	43	#define MAX30100_REG_FIFO_RD_PTR 0x04
	44	#define MAX30100_REG_FIFO_DATA 0x05
	45	#define MAX30100_REG_FIFO_DATA_ENTRY_COUNT 16
	46	#define MAX30100_REG_FIFO_DATA_ENTRY_LEN 4
	47
	48	#define MAX30100_REG_MODE_CONFIG 0x06
	49	#define MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN BIT(0)
	50	#define MAX30100_REG_MODE_CONFIG_MODE_HR_EN BIT(1)
	51	#define MAX30100_REG_MODE_CONFIG_MODE_MASK 0x03
	52	#define MAX30100_REG_MODE_CONFIG_TEMP_EN BIT(3)
	53	#define MAX30100_REG_MODE_CONFIG_PWR BIT(7)
	54
	55	#define MAX30100_REG_SPO2_CONFIG 0x07
	56	#define MAX30100_REG_SPO2_CONFIG_100HZ BIT(2)
	57	#define MAX30100_REG_SPO2_CONFIG_HI_RES_EN BIT(6)
	58	#define MAX30100_REG_SPO2_CONFIG_1600US 0x3
	59
	60	#define MAX30100_REG_LED_CONFIG 0x09
b11a3460	61	#define MAX30100_REG_LED_CONFIG_LED_MASK 0x0f
4d33615d MR	62	#define MAX30100_REG_LED_CONFIG_RED_LED_SHIFT 4
	63
	64	#define MAX30100_REG_LED_CONFIG_24MA 0x07
	65	#define MAX30100_REG_LED_CONFIG_50MA 0x0f
	66
	67	#define MAX30100_REG_TEMP_INTEGER 0x16
	68	#define MAX30100_REG_TEMP_FRACTION 0x17
	69
	70	struct max30100_data {
	71	struct i2c_client *client;
	72	struct iio_dev *indio_dev;
	73	struct mutex lock;
	74	struct regmap *regmap;
	75
	76	__be16 buffer[2]; /* 2 16-bit channels */
	77	};
	78
	79	static bool max30100_is_volatile_reg(struct device *dev, unsigned int reg)
	80	{
	81	switch (reg) {
	82	case MAX30100_REG_INT_STATUS:
	83	case MAX30100_REG_MODE_CONFIG:
	84	case MAX30100_REG_FIFO_WR_PTR:
	85	case MAX30100_REG_FIFO_OVR_CTR:
	86	case MAX30100_REG_FIFO_RD_PTR:
	87	case MAX30100_REG_FIFO_DATA:
	88	case MAX30100_REG_TEMP_INTEGER:
	89	case MAX30100_REG_TEMP_FRACTION:
	90	return true;
	91	default:
	92	return false;
	93	}
	94	}
	95
	96	static const struct regmap_config max30100_regmap_config = {
	97	.name = MAX30100_REGMAP_NAME,
	98
	99	.reg_bits = 8,
	100	.val_bits = 8,
	101
	102	.max_register = MAX30100_REG_TEMP_FRACTION,
	103	.cache_type = REGCACHE_FLAT,
	104
	105	.volatile_reg = max30100_is_volatile_reg,
	106	};
	107
b11a3460 MR	108	static const unsigned int max30100_led_current_mapping[] = {
	109	4400, 7600, 11000, 14200, 17400,
	110	20800, 24000, 27100, 30600, 33800,
	111	37000, 40200, 43600, 46800, 50000
	112	};
	113
4d33615d MR	114	static const unsigned long max30100_scan_masks[] = {0x3, 0};
	115
	116	static const struct iio_chan_spec max30100_channels[] = {
	117	{
	118	.type = IIO_INTENSITY,
	119	.channel2 = IIO_MOD_LIGHT_IR,
	120	.modified = 1,
	121
	122	.scan_index = 0,
	123	.scan_type = {
	124	.sign = 'u',
	125	.realbits = 16,
	126	.storagebits = 16,
	127	.endianness = IIO_BE,
	128	},
	129	},
	130	{
	131	.type = IIO_INTENSITY,
	132	.channel2 = IIO_MOD_LIGHT_RED,
	133	.modified = 1,
	134
	135	.scan_index = 1,
	136	.scan_type = {
	137	.sign = 'u',
	138	.realbits = 16,
	139	.storagebits = 16,
	140	.endianness = IIO_BE,
	141	},
	142	},
	143	{
	144	.type = IIO_TEMP,
	145	.info_mask_separate =
	146	BIT(IIO_CHAN_INFO_RAW) \| BIT(IIO_CHAN_INFO_SCALE),
	147	.scan_index = -1,
	148	},
	149	};
	150
	151	static int max30100_set_powermode(struct max30100_data *data, bool state)
	152	{
	153	return regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
	154	MAX30100_REG_MODE_CONFIG_PWR,
	155	state ? 0 : MAX30100_REG_MODE_CONFIG_PWR);
	156	}
	157
	158	static int max30100_clear_fifo(struct max30100_data *data)
	159	{
	160	int ret;
	161
	162	ret = regmap_write(data->regmap, MAX30100_REG_FIFO_WR_PTR, 0);
	163	if (ret)
	164	return ret;
	165
	166	ret = regmap_write(data->regmap, MAX30100_REG_FIFO_OVR_CTR, 0);
	167	if (ret)
	168	return ret;
	169
	170	return regmap_write(data->regmap, MAX30100_REG_FIFO_RD_PTR, 0);
	171	}
	172
	173	static int max30100_buffer_postenable(struct iio_dev *indio_dev)
	174	{
	175	struct max30100_data *data = iio_priv(indio_dev);
	176	int ret;
	177
178	ret = max30100_set_powermode(data, true);
179	if (ret)
180	return ret;
181
182	return max30100_clear_fifo(data);
183	}
184
185	static int max30100_buffer_predisable(struct iio_dev *indio_dev)
186	{
187	struct max30100_data *data = iio_priv(indio_dev);
188
189	return max30100_set_powermode(data, false);
190	}
191
192	static const struct iio_buffer_setup_ops max30100_buffer_setup_ops = {
193	.postenable = max30100_buffer_postenable,
194	.predisable = max30100_buffer_predisable,
195	};
196
197	static inline int max30100_fifo_count(struct max30100_data *data)
198	{
199	unsigned int val;
200	int ret;
201
202	ret = regmap_read(data->regmap, MAX30100_REG_INT_STATUS, &val);
203	if (ret)
204	return ret;
205
206	/* FIFO is almost full */
207	if (val & MAX30100_REG_INT_STATUS_FIFO_RDY)
208	return MAX30100_REG_FIFO_DATA_ENTRY_COUNT - 1;
209
210	return 0;
211	}
212
213	static int max30100_read_measurement(struct max30100_data *data)
214	{
215	int ret;
216
217	ret = i2c_smbus_read_i2c_block_data(data->client,
218	MAX30100_REG_FIFO_DATA,
219	MAX30100_REG_FIFO_DATA_ENTRY_LEN,
220	(u8 *) &data->buffer);
221
222	return (ret == MAX30100_REG_FIFO_DATA_ENTRY_LEN) ? 0 : ret;
223	}
224
225	static irqreturn_t max30100_interrupt_handler(int irq, void *private)
226	{
227	struct iio_dev *indio_dev = private;
228	struct max30100_data *data = iio_priv(indio_dev);
229	int ret, cnt = 0;
230
231	mutex_lock(&data->lock);
232
828f84ee	233	while (cnt \|\| (cnt = max30100_fifo_count(data)) > 0) {
4d33615d MR	234	ret = max30100_read_measurement(data);
	235	if (ret)
	236	break;
	237
	238	iio_push_to_buffers(data->indio_dev, data->buffer);
b74fccad	239	cnt--;
4d33615d MR	240	}
	241
	242	mutex_unlock(&data->lock);
	243
	244	return IRQ_HANDLED;
	245	}
	246
b11a3460 MR	247	static int max30100_get_current_idx(unsigned int val, int *reg)
	248	{
	249	int idx;
	250
	251	/* LED turned off */
	252	if (val == 0) {
	253	*reg = 0;
	254	return 0;
	255	}
	256
	257	for (idx = 0; idx < ARRAY_SIZE(max30100_led_current_mapping); idx++) {
	258	if (max30100_led_current_mapping[idx] == val) {
	259	*reg = idx + 1;
	260	return 0;
	261	}
	262	}
	263
	264	return -EINVAL;
	265	}
	266
	267	static int max30100_led_init(struct max30100_data *data)
	268	{
	269	struct device *dev = &data->client->dev;
	270	struct device_node *np = dev->of_node;
	271	unsigned int val[2];
	272	int reg, ret;
	273
	274	ret = of_property_read_u32_array(np, "maxim,led-current-microamp",
	275	(unsigned int *) &val, 2);
	276	if (ret) {
	277	/* Default to 24 mA RED LED, 50 mA IR LED */
	278	reg = (MAX30100_REG_LED_CONFIG_24MA <<
	279	MAX30100_REG_LED_CONFIG_RED_LED_SHIFT) \|
	280	MAX30100_REG_LED_CONFIG_50MA;
	281	dev_warn(dev, "no led-current-microamp set");
	282
	283	return regmap_write(data->regmap, MAX30100_REG_LED_CONFIG, reg);
	284	}
	285
	286	/* RED LED current */
	287	ret = max30100_get_current_idx(val[0], &reg);
	288	if (ret) {
	289	dev_err(dev, "invalid RED current setting %d", val[0]);
	290	return ret;
	291	}
	292
	293	ret = regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
	294	MAX30100_REG_LED_CONFIG_LED_MASK <<
	295	MAX30100_REG_LED_CONFIG_RED_LED_SHIFT,
	296	reg << MAX30100_REG_LED_CONFIG_RED_LED_SHIFT);
	297	if (ret)
	298	return ret;
	299
	300	/* IR LED current */
	301	ret = max30100_get_current_idx(val[1], &reg);
	302	if (ret) {
	303	dev_err(dev, "invalid IR current setting %d", val[1]);
	304	return ret;
	305	}
	306
	307	return regmap_update_bits(data->regmap, MAX30100_REG_LED_CONFIG,
	308	MAX30100_REG_LED_CONFIG_LED_MASK, reg);
	309	}
	310
4d33615d MR	311	static int max30100_chip_init(struct max30100_data *data)
	312	{
	313	int ret;
	314
b11a3460 MR	315	/* setup LED current settings */
b11a3460 MR	316	ret = max30100_led_init(data);
4d33615d MR	317	if (ret)
	318	return ret;
	319
	320	/* enable hi-res SPO2 readings at 100Hz */
	321	ret = regmap_write(data->regmap, MAX30100_REG_SPO2_CONFIG,
	322	MAX30100_REG_SPO2_CONFIG_HI_RES_EN \|
	323	MAX30100_REG_SPO2_CONFIG_100HZ);
	324	if (ret)
	325	return ret;
	326
	327	/* enable SPO2 mode */
	328	ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
	329	MAX30100_REG_MODE_CONFIG_MODE_MASK,
	330	MAX30100_REG_MODE_CONFIG_MODE_HR_EN \|
	331	MAX30100_REG_MODE_CONFIG_MODE_SPO2_EN);
	332	if (ret)
	333	return ret;
	334
	335	/* enable FIFO interrupt */
	336	return regmap_update_bits(data->regmap, MAX30100_REG_INT_ENABLE,
	337	MAX30100_REG_INT_ENABLE_MASK,
	338	MAX30100_REG_INT_ENABLE_FIFO_EN
	339	<< MAX30100_REG_INT_ENABLE_MASK_SHIFT);
	340	}
	341
	342	static int max30100_read_temp(struct max30100_data data, int val)
	343	{
	344	int ret;
	345	unsigned int reg;
	346
	347	ret = regmap_read(data->regmap, MAX30100_REG_TEMP_INTEGER, &reg);
	348	if (ret < 0)
	349	return ret;
	350	*val = reg << 4;
	351
	352	ret = regmap_read(data->regmap, MAX30100_REG_TEMP_FRACTION, &reg);
	353	if (ret < 0)
	354	return ret;
	355
	356	*val \|= reg & 0xf;
	357	val = sign_extend32(val, 11);
	358
	359	return 0;
	360	}
	361
	362	static int max30100_get_temp(struct max30100_data data, int val)
	363	{
	364	int ret;
	365
	366	/* start acquisition */
	367	ret = regmap_update_bits(data->regmap, MAX30100_REG_MODE_CONFIG,
	368	MAX30100_REG_MODE_CONFIG_TEMP_EN,
	369	MAX30100_REG_MODE_CONFIG_TEMP_EN);
	370	if (ret)
	371	return ret;
	372
18e2452a	373	msleep(35);
4d33615d MR	374
	375	return max30100_read_temp(data, val);
	376	}
	377
	378	static int max30100_read_raw(struct iio_dev *indio_dev,
	379	struct iio_chan_spec const *chan,
	380	int val, int val2, long mask)
	381	{
	382	struct max30100_data *data = iio_priv(indio_dev);
	383	int ret = -EINVAL;
	384
	385	switch (mask) {
	386	case IIO_CHAN_INFO_RAW:
	387	/*
	388	* Temperature reading can only be acquired while engine
	389	* is running
	390	*/
	391	mutex_lock(&indio_dev->mlock);
	392
	393	if (!iio_buffer_enabled(indio_dev))
	394	ret = -EAGAIN;
	395	else {
	396	ret = max30100_get_temp(data, val);
	397	if (!ret)
	398	ret = IIO_VAL_INT;
	399
	400	}
	401
	402	mutex_unlock(&indio_dev->mlock);
	403	break;
	404	case IIO_CHAN_INFO_SCALE:
	405	val = 1; / 0.0625 */
	406	*val2 = 16;
	407	ret = IIO_VAL_FRACTIONAL;
	408	break;
	409	}
	410
	411	return ret;
	412	}
	413
	414	static const struct iio_info max30100_info = {
4d33615d MR	415	.read_raw = max30100_read_raw,
	416	};
	417
	418	static int max30100_probe(struct i2c_client *client,
	419	const struct i2c_device_id *id)
	420	{
	421	struct max30100_data *data;
	422	struct iio_buffer *buffer;
	423	struct iio_dev *indio_dev;
	424	int ret;
	425
	426	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	427	if (!indio_dev)
	428	return -ENOMEM;
	429
	430	buffer = devm_iio_kfifo_allocate(&client->dev);
	431	if (!buffer)
	432	return -ENOMEM;
	433
	434	iio_device_attach_buffer(indio_dev, buffer);
	435
	436	indio_dev->name = MAX30100_DRV_NAME;
	437	indio_dev->channels = max30100_channels;
	438	indio_dev->info = &max30100_info;
	439	indio_dev->num_channels = ARRAY_SIZE(max30100_channels);
	440	indio_dev->available_scan_masks = max30100_scan_masks;
	441	indio_dev->modes = (INDIO_BUFFER_SOFTWARE \| INDIO_DIRECT_MODE);
	442	indio_dev->setup_ops = &max30100_buffer_setup_ops;
5d548b73	443	indio_dev->dev.parent = &client->dev;
4d33615d MR	444
	445	data = iio_priv(indio_dev);
	446	data->indio_dev = indio_dev;
	447	data->client = client;
	448
	449	mutex_init(&data->lock);
	450	i2c_set_clientdata(client, indio_dev);
	451
	452	data->regmap = devm_regmap_init_i2c(client, &max30100_regmap_config);
	453	if (IS_ERR(data->regmap)) {
	454	dev_err(&client->dev, "regmap initialization failed.\n");
	455	return PTR_ERR(data->regmap);
	456	}
	457	max30100_set_powermode(data, false);
	458
	459	ret = max30100_chip_init(data);
	460	if (ret)
	461	return ret;
	462
	463	if (client->irq <= 0) {
	464	dev_err(&client->dev, "no valid irq defined\n");
	465	return -EINVAL;
	466	}
	467	ret = devm_request_threaded_irq(&client->dev, client->irq,
	468	NULL, max30100_interrupt_handler,
	469	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	470	"max30100_irq", indio_dev);
	471	if (ret) {
	472	dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
	473	return ret;
	474	}
	475
	476	return iio_device_register(indio_dev);
	477	}
	478
	479	static int max30100_remove(struct i2c_client *client)
	480	{
	481	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	482	struct max30100_data *data = iio_priv(indio_dev);
	483
	484	iio_device_unregister(indio_dev);
	485	max30100_set_powermode(data, false);
	486
	487	return 0;
	488	}
	489
	490	static const struct i2c_device_id max30100_id[] = {
	491	{ "max30100", 0 },
	492	{}
	493	};
	494	MODULE_DEVICE_TABLE(i2c, max30100_id);
	495
	496	static const struct of_device_id max30100_dt_ids[] = {
	497	{ .compatible = "maxim,max30100" },
	498	{ }
	499	};
	500	MODULE_DEVICE_TABLE(of, max30100_dt_ids);
	501
	502	static struct i2c_driver max30100_driver = {
	503	.driver = {
	504	.name = MAX30100_DRV_NAME,
	505	.of_match_table = of_match_ptr(max30100_dt_ids),
	506	},
	507	.probe = max30100_probe,
508	.remove = max30100_remove,
509	.id_table = max30100_id,
510	};
511	module_i2c_driver(max30100_driver);
512
d6ad8058	513	MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
4d33615d MR	514	MODULE_DESCRIPTION("MAX30100 heart rate and pulse oximeter sensor");
4d33615d MR	515	MODULE_LICENSE("GPL");