[mirror_ubuntu-bionic-kernel.git] / drivers / iio / light / vl6180.c

/*
 * vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity
 * sensor
 *
 * Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
 * Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * IIO driver for VL6180 (7-bit I2C slave address 0x29)
 *
 * Range: 0 to 100mm
 * ALS: < 1 Lux up to 100 kLux
 * IR: 850nm
 *
 * TODO: irq, threshold events, continuous mode, hardware buffer
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/util_macros.h>

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

#define VL6180_DRV_NAME "vl6180"

/* Device identification register and value */
#define VL6180_MODEL_ID	0x000
#define VL6180_MODEL_ID_VAL 0xb4

/* Configuration registers */
#define VL6180_INTR_CONFIG 0x014
#define VL6180_INTR_CLEAR 0x015
#define VL6180_OUT_OF_RESET 0x016
#define VL6180_HOLD 0x017
#define VL6180_RANGE_START 0x018
#define VL6180_ALS_START 0x038
#define VL6180_ALS_GAIN 0x03f
#define VL6180_ALS_IT 0x040

/* Status registers */
#define VL6180_RANGE_STATUS 0x04d
#define VL6180_ALS_STATUS 0x04e
#define VL6180_INTR_STATUS 0x04f

/* Result value registers */
#define VL6180_ALS_VALUE 0x050
#define VL6180_RANGE_VALUE 0x062
#define VL6180_RANGE_RATE 0x066

/* bits of the RANGE_START and ALS_START register */
#define VL6180_MODE_CONT BIT(1) /* continuous mode */
#define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */

/* bits of the INTR_STATUS and INTR_CONFIG register */
#define VL6180_ALS_READY BIT(5)
#define VL6180_RANGE_READY BIT(2)

/* bits of the INTR_CLEAR register */
#define VL6180_CLEAR_ERROR BIT(2)
#define VL6180_CLEAR_ALS BIT(1)
#define VL6180_CLEAR_RANGE BIT(0)

/* bits of the HOLD register */
#define VL6180_HOLD_ON BIT(0)

/* default value for the ALS_IT register */
#define VL6180_ALS_IT_100 0x63 /* 100 ms */

/* values for the ALS_GAIN register */
#define VL6180_ALS_GAIN_1 0x46
#define VL6180_ALS_GAIN_1_25 0x45
#define VL6180_ALS_GAIN_1_67 0x44
#define VL6180_ALS_GAIN_2_5 0x43
#define VL6180_ALS_GAIN_5 0x42
#define VL6180_ALS_GAIN_10 0x41
#define VL6180_ALS_GAIN_20 0x40
#define VL6180_ALS_GAIN_40 0x47

struct vl6180_data {
	struct i2c_client *client;
	struct mutex lock;
	unsigned int als_gain_milli;
	unsigned int als_it_ms;
};

enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };

/**
 * struct vl6180_chan_regs - Registers for accessing channels
 * @drdy_mask:			Data ready bit in status register
 * @start_reg:			Conversion start register
 * @value_reg:			Result value register
 * @word:			Register word length
 */
struct vl6180_chan_regs {
	u8 drdy_mask;
	u16 start_reg, value_reg;
	bool word;
};

static const struct vl6180_chan_regs vl6180_chan_regs_table[] = {
	[VL6180_ALS] = {
		.drdy_mask = VL6180_ALS_READY,
		.start_reg = VL6180_ALS_START,
		.value_reg = VL6180_ALS_VALUE,
		.word = true,
	},
	[VL6180_RANGE] = {
		.drdy_mask = VL6180_RANGE_READY,
		.start_reg = VL6180_RANGE_START,
		.value_reg = VL6180_RANGE_VALUE,
		.word = false,
	},
	[VL6180_PROX] = {
		.drdy_mask = VL6180_RANGE_READY,
		.start_reg = VL6180_RANGE_START,
		.value_reg = VL6180_RANGE_RATE,
		.word = true,
	},
};

static int vl6180_read(struct i2c_client *client, u16 cmd, void *databuf,
		       u8 len)
{
	__be16 cmdbuf = cpu_to_be16(cmd);
	struct i2c_msg msgs[2] = {
		{ .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf },
		{ .addr = client->addr, .len = len, .buf = databuf,
		  .flags = I2C_M_RD } };
	int ret;

	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret < 0)
		dev_err(&client->dev, "failed reading register 0x%04x\n", cmd);

	return ret;
}

static int vl6180_read_byte(struct i2c_client *client, u16 cmd)
{
	u8 data;
	int ret;

	ret = vl6180_read(client, cmd, &data, sizeof(data));
	if (ret < 0)
		return ret;

	return data;
}

static int vl6180_read_word(struct i2c_client *client, u16 cmd)
{
	__be16 data;
	int ret;

	ret = vl6180_read(client, cmd, &data, sizeof(data));
	if (ret < 0)
		return ret;

	return be16_to_cpu(data);
}

static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val)
{
	u8 buf[3];
	struct i2c_msg msgs[1] = {
		{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
	int ret;

	buf[0] = cmd >> 8;
	buf[1] = cmd & 0xff;
	buf[2] = val;

	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret < 0) {
		dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
		return ret;
	}

	return 0;
}

static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val)
{
	__be16 buf[2];
	struct i2c_msg msgs[1] = {
		{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
	int ret;

	buf[0] = cpu_to_be16(cmd);
	buf[1] = cpu_to_be16(val);

	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret < 0) {
		dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
		return ret;
	}

	return 0;
}

static int vl6180_measure(struct vl6180_data *data, int addr)
{
	struct i2c_client *client = data->client;
	int tries = 20, ret;
	u16 value;

	mutex_lock(&data->lock);
	/* Start single shot measurement */
	ret = vl6180_write_byte(client,
		vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP);
	if (ret < 0)
		goto fail;

	while (tries--) {
		ret = vl6180_read_byte(client, VL6180_INTR_STATUS);
		if (ret < 0)
			goto fail;

		if (ret & vl6180_chan_regs_table[addr].drdy_mask)
			break;
		msleep(20);
	}

	if (tries < 0) {
		ret = -EIO;
		goto fail;
	}

	/* Read result value from appropriate registers */
	ret = vl6180_chan_regs_table[addr].word ?
		vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) :
		vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg);
	if (ret < 0)
		goto fail;
	value = ret;

	/* Clear the interrupt flag after data read */
	ret = vl6180_write_byte(client, VL6180_INTR_CLEAR,
		VL6180_CLEAR_ERROR | VL6180_CLEAR_ALS | VL6180_CLEAR_RANGE);
	if (ret < 0)
		goto fail;

	ret = value;

fail:
	mutex_unlock(&data->lock);

	return ret;
}

static const struct iio_chan_spec vl6180_channels[] = {
	{
		.type = IIO_LIGHT,
		.address = VL6180_ALS,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_INT_TIME) |
			BIT(IIO_CHAN_INFO_SCALE) |
			BIT(IIO_CHAN_INFO_HARDWAREGAIN),
	}, {
		.type = IIO_DISTANCE,
		.address = VL6180_RANGE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
			BIT(IIO_CHAN_INFO_SCALE),
	}, {
		.type = IIO_PROXIMITY,
		.address = VL6180_PROX,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
	}
};

/*
 * Available Ambient Light Sensor gain settings, 1/1000th, and
 * corresponding setting for the VL6180_ALS_GAIN register
 */
static const int vl6180_als_gain_tab[8] = {
	1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000
};
static const u8 vl6180_als_gain_tab_bits[8] = {
	VL6180_ALS_GAIN_1,    VL6180_ALS_GAIN_1_25,
	VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5,
	VL6180_ALS_GAIN_5,    VL6180_ALS_GAIN_10,
	VL6180_ALS_GAIN_20,   VL6180_ALS_GAIN_40
};

static int vl6180_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct vl6180_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = vl6180_measure(data, chan->address);
		if (ret < 0)
			return ret;
		*val = ret;

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_INT_TIME:
		*val = data->als_it_ms;
		*val2 = 1000;

		return IIO_VAL_FRACTIONAL;

	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_LIGHT:
			/* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
			*val = 32000; /* 0.32 * 1000 * 100 */
			*val2 = data->als_gain_milli * data->als_it_ms;

			return IIO_VAL_FRACTIONAL;

		case IIO_DISTANCE:
			*val = 0; /* sensor reports mm, scale to meter */
			*val2 = 1000;
			break;
		default:
			return -EINVAL;
		}

		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_HARDWAREGAIN:
		*val = data->als_gain_milli;
		*val2 = 1000;

		return IIO_VAL_FRACTIONAL;

	default:
		return -EINVAL;
	}
}

static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40");

static struct attribute *vl6180_attributes[] = {
	&iio_const_attr_als_gain_available.dev_attr.attr,
	NULL
};

static const struct attribute_group vl6180_attribute_group = {
	.attrs = vl6180_attributes,
};

/* HOLD is needed before updating any config registers */
static int vl6180_hold(struct vl6180_data *data, bool hold)
{
	return vl6180_write_byte(data->client, VL6180_HOLD,
		hold ? VL6180_HOLD_ON : 0);
}

static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2)
{
	int i, ret, gain;

	if (val < 1 || val > 40)
		return -EINVAL;

	gain = (val * 1000000 + val2) / 1000;
	if (gain < 1 || gain > 40000)
		return -EINVAL;

	i = find_closest(gain, vl6180_als_gain_tab,
			 ARRAY_SIZE(vl6180_als_gain_tab));

	mutex_lock(&data->lock);
	ret = vl6180_hold(data, true);
	if (ret < 0)
		goto fail;

	ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN,
				vl6180_als_gain_tab_bits[i]);

	if (ret >= 0)
		data->als_gain_milli = vl6180_als_gain_tab[i];

fail:
	vl6180_hold(data, false);
	mutex_unlock(&data->lock);
	return ret;
}

static int vl6180_set_it(struct vl6180_data *data, int val, int val2)
{
	int ret, it_ms;

	it_ms = (val2 + 500) / 1000; /* round to ms */
	if (val != 0 || it_ms < 1 || it_ms > 512)
		return -EINVAL;

	mutex_lock(&data->lock);
	ret = vl6180_hold(data, true);
	if (ret < 0)
		goto fail;

	ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1);

	if (ret >= 0)
		data->als_it_ms = it_ms;

fail:
	vl6180_hold(data, false);
	mutex_unlock(&data->lock);

	return ret;
}

static int vl6180_write_raw(struct iio_dev *indio_dev,
			     struct iio_chan_spec const *chan,
			     int val, int val2, long mask)
{
	struct vl6180_data *data = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_INT_TIME:
		return vl6180_set_it(data, val, val2);

	case IIO_CHAN_INFO_HARDWAREGAIN:
		if (chan->type != IIO_LIGHT)
			return -EINVAL;

		return vl6180_set_als_gain(data, val, val2);
	default:
		return -EINVAL;
	}
}

static const struct iio_info vl6180_info = {
	.read_raw = vl6180_read_raw,
	.write_raw = vl6180_write_raw,
	.attrs = &vl6180_attribute_group,
};

static int vl6180_init(struct vl6180_data *data)
{
	struct i2c_client *client = data->client;
	int ret;

	ret = vl6180_read_byte(client, VL6180_MODEL_ID);
	if (ret < 0)
		return ret;

	if (ret != VL6180_MODEL_ID_VAL) {
		dev_err(&client->dev, "invalid model ID %02x\n", ret);
		return -ENODEV;
	}

	ret = vl6180_hold(data, true);
	if (ret < 0)
		return ret;

	ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET);
	if (ret < 0)
		return ret;

	/*
	 * Detect false reset condition here. This bit is always set when the
	 * system comes out of reset.
	 */
	if (ret != 0x01)
		dev_info(&client->dev, "device is not fresh out of reset\n");

	/* Enable ALS and Range ready interrupts */
	ret = vl6180_write_byte(client, VL6180_INTR_CONFIG,
				VL6180_ALS_READY | VL6180_RANGE_READY);
	if (ret < 0)
		return ret;

	/* ALS integration time: 100ms */
	data->als_it_ms = 100;
	ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
	if (ret < 0)
		return ret;

	/* ALS gain: 1 */
	data->als_gain_milli = 1000;
	ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1);
	if (ret < 0)
		return ret;

	ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00);
	if (ret < 0)
		return ret;

	return vl6180_hold(data, false);
}

static int vl6180_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct vl6180_data *data;
	struct iio_dev *indio_dev;
	int ret;

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

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

	indio_dev->dev.parent = &client->dev;
	indio_dev->info = &vl6180_info;
	indio_dev->channels = vl6180_channels;
	indio_dev->num_channels = ARRAY_SIZE(vl6180_channels);
	indio_dev->name = VL6180_DRV_NAME;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = vl6180_init(data);
	if (ret < 0)
		return ret;

	return devm_iio_device_register(&client->dev, indio_dev);
}

static const struct of_device_id vl6180_of_match[] = {
	{ .compatible = "st,vl6180", },
	{ },
};
MODULE_DEVICE_TABLE(of, vl6180_of_match);

static const struct i2c_device_id vl6180_id[] = {
	{ "vl6180", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, vl6180_id);

static struct i2c_driver vl6180_driver = {
	.driver = {
		.name   = VL6180_DRV_NAME,
		.of_match_table = of_match_ptr(vl6180_of_match),
	},
	.probe  = vl6180_probe,
	.id_table = vl6180_id,
};

module_i2c_driver(vl6180_driver);

MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
5e7f47e4 MS	1	/*
	2	* vl6180.c - Support for STMicroelectronics VL6180 ALS, range and proximity
	3	* sensor
	4	*
	5	* Copyright 2017 Peter Meerwald-Stadler <pmeerw@pmeerw.net>
	6	* Copyright 2017 Manivannan Sadhasivam <manivannanece23@gmail.com>
	7	*
	8	* This file is subject to the terms and conditions of version 2 of
	9	* the GNU General Public License. See the file COPYING in the main
	10	* directory of this archive for more details.
	11	*
	12	* IIO driver for VL6180 (7-bit I2C slave address 0x29)
	13	*
	14	* Range: 0 to 100mm
	15	* ALS: < 1 Lux up to 100 kLux
	16	* IR: 850nm
	17	*
	18	* TODO: irq, threshold events, continuous mode, hardware buffer
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/i2c.h>
	23	#include <linux/mutex.h>
	24	#include <linux/err.h>
	25	#include <linux/of.h>
	26	#include <linux/delay.h>
e794bf67	27	#include <linux/util_macros.h>
5e7f47e4 MS	28
	29	#include <linux/iio/iio.h>
	30	#include <linux/iio/sysfs.h>
	31
	32	#define VL6180_DRV_NAME "vl6180"
	33
	34	/* Device identification register and value */
	35	#define VL6180_MODEL_ID 0x000
	36	#define VL6180_MODEL_ID_VAL 0xb4
	37
	38	/* Configuration registers */
	39	#define VL6180_INTR_CONFIG 0x014
	40	#define VL6180_INTR_CLEAR 0x015
	41	#define VL6180_OUT_OF_RESET 0x016
	42	#define VL6180_HOLD 0x017
	43	#define VL6180_RANGE_START 0x018
	44	#define VL6180_ALS_START 0x038
	45	#define VL6180_ALS_GAIN 0x03f
	46	#define VL6180_ALS_IT 0x040
	47
	48	/* Status registers */
	49	#define VL6180_RANGE_STATUS 0x04d
	50	#define VL6180_ALS_STATUS 0x04e
	51	#define VL6180_INTR_STATUS 0x04f
	52
	53	/* Result value registers */
	54	#define VL6180_ALS_VALUE 0x050
	55	#define VL6180_RANGE_VALUE 0x062
	56	#define VL6180_RANGE_RATE 0x066
	57
	58	/* bits of the RANGE_START and ALS_START register */
	59	#define VL6180_MODE_CONT BIT(1) /* continuous mode */
	60	#define VL6180_STARTSTOP BIT(0) /* start measurement, auto-reset */
	61
	62	/* bits of the INTR_STATUS and INTR_CONFIG register */
	63	#define VL6180_ALS_READY BIT(5)
	64	#define VL6180_RANGE_READY BIT(2)
	65
	66	/* bits of the INTR_CLEAR register */
	67	#define VL6180_CLEAR_ERROR BIT(2)
	68	#define VL6180_CLEAR_ALS BIT(1)
	69	#define VL6180_CLEAR_RANGE BIT(0)
	70
	71	/* bits of the HOLD register */
	72	#define VL6180_HOLD_ON BIT(0)
	73
	74	/* default value for the ALS_IT register */
	75	#define VL6180_ALS_IT_100 0x63 /* 100 ms */
	76
	77	/* values for the ALS_GAIN register */
	78	#define VL6180_ALS_GAIN_1 0x46
	79	#define VL6180_ALS_GAIN_1_25 0x45
	80	#define VL6180_ALS_GAIN_1_67 0x44
	81	#define VL6180_ALS_GAIN_2_5 0x43
	82	#define VL6180_ALS_GAIN_5 0x42
	83	#define VL6180_ALS_GAIN_10 0x41
	84	#define VL6180_ALS_GAIN_20 0x40
	85	#define VL6180_ALS_GAIN_40 0x47
	86
	87	struct vl6180_data {
	88	struct i2c_client *client;
	89	struct mutex lock;
e794bf67	90	unsigned int als_gain_milli;
df698c04	91	unsigned int als_it_ms;
5e7f47e4 MS	92	};
	93
	94	enum { VL6180_ALS, VL6180_RANGE, VL6180_PROX };
	95
	96	/**
	97	* struct vl6180_chan_regs - Registers for accessing channels
	98	* @drdy_mask: Data ready bit in status register
	99	* @start_reg: Conversion start register
	100	* @value_reg: Result value register
	101	* @word: Register word length
	102	*/
	103	struct vl6180_chan_regs {
	104	u8 drdy_mask;
	105	u16 start_reg, value_reg;
	106	bool word;
	107	};
	108
	109	static const struct vl6180_chan_regs vl6180_chan_regs_table[] = {
	110	[VL6180_ALS] = {
	111	.drdy_mask = VL6180_ALS_READY,
	112	.start_reg = VL6180_ALS_START,
	113	.value_reg = VL6180_ALS_VALUE,
	114	.word = true,
	115	},
	116	[VL6180_RANGE] = {
	117	.drdy_mask = VL6180_RANGE_READY,
	118	.start_reg = VL6180_RANGE_START,
	119	.value_reg = VL6180_RANGE_VALUE,
	120	.word = false,
	121	},
	122	[VL6180_PROX] = {
	123	.drdy_mask = VL6180_RANGE_READY,
	124	.start_reg = VL6180_RANGE_START,
	125	.value_reg = VL6180_RANGE_RATE,
	126	.word = true,
	127	},
	128	};
	129
	130	static int vl6180_read(struct i2c_client client, u16 cmd, void databuf,
	131	u8 len)
	132	{
	133	__be16 cmdbuf = cpu_to_be16(cmd);
	134	struct i2c_msg msgs[2] = {
	135	{ .addr = client->addr, .len = sizeof(cmdbuf), .buf = (u8 *) &cmdbuf },
	136	{ .addr = client->addr, .len = len, .buf = databuf,
	137	.flags = I2C_M_RD } };
	138	int ret;
	139
	140	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	141	if (ret < 0)
	142	dev_err(&client->dev, "failed reading register 0x%04x\n", cmd);
	143
	144	return ret;
	145	}
	146
	147	static int vl6180_read_byte(struct i2c_client *client, u16 cmd)
	148	{
	149	u8 data;
	150	int ret;
	151
	152	ret = vl6180_read(client, cmd, &data, sizeof(data));
	153	if (ret < 0)
	154	return ret;
	155
156	return data;
157	}
158
159	static int vl6180_read_word(struct i2c_client *client, u16 cmd)
160	{
161	__be16 data;
162	int ret;
163
164	ret = vl6180_read(client, cmd, &data, sizeof(data));
165	if (ret < 0)
166	return ret;
167
168	return be16_to_cpu(data);
169	}
170
171	static int vl6180_write_byte(struct i2c_client *client, u16 cmd, u8 val)
172	{
173	u8 buf[3];
174	struct i2c_msg msgs[1] = {
175	{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
176	int ret;
177
178	buf[0] = cmd >> 8;
179	buf[1] = cmd & 0xff;
180	buf[2] = val;
181
182	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
183	if (ret < 0) {
184	dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
185	return ret;
186	}
187
188	return 0;
189	}
190
191	static int vl6180_write_word(struct i2c_client *client, u16 cmd, u16 val)
192	{
193	__be16 buf[2];
194	struct i2c_msg msgs[1] = {
195	{ .addr = client->addr, .len = sizeof(buf), .buf = (u8 *) &buf } };
196	int ret;
197
198	buf[0] = cpu_to_be16(cmd);
199	buf[1] = cpu_to_be16(val);
200
201	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
202	if (ret < 0) {
203	dev_err(&client->dev, "failed writing register 0x%04x\n", cmd);
204	return ret;
205	}
206
207	return 0;
208	}
209
210	static int vl6180_measure(struct vl6180_data *data, int addr)
211	{
212	struct i2c_client *client = data->client;
213	int tries = 20, ret;
214	u16 value;
215
216	mutex_lock(&data->lock);
217	/* Start single shot measurement */
218	ret = vl6180_write_byte(client,
219	vl6180_chan_regs_table[addr].start_reg, VL6180_STARTSTOP);
220	if (ret < 0)
221	goto fail;
222
223	while (tries--) {
224	ret = vl6180_read_byte(client, VL6180_INTR_STATUS);
225	if (ret < 0)
226	goto fail;
227
228	if (ret & vl6180_chan_regs_table[addr].drdy_mask)
229	break;
230	msleep(20);
231	}
232
233	if (tries < 0) {
234	ret = -EIO;
235	goto fail;
236	}
237
238	/* Read result value from appropriate registers */
239	ret = vl6180_chan_regs_table[addr].word ?
240	vl6180_read_word(client, vl6180_chan_regs_table[addr].value_reg) :
241	vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg);
242	if (ret < 0)
243	goto fail;
244	value = ret;
245
246	/* Clear the interrupt flag after data read */
247	ret = vl6180_write_byte(client, VL6180_INTR_CLEAR,
248	VL6180_CLEAR_ERROR \| VL6180_CLEAR_ALS \| VL6180_CLEAR_RANGE);
249	if (ret < 0)
250	goto fail;
251
252	ret = value;
253
254	fail:
255	mutex_unlock(&data->lock);
256
257	return ret;
258	}
259
260	static const struct iio_chan_spec vl6180_channels[] = {
261	{
262	.type = IIO_LIGHT,
263	.address = VL6180_ALS,
264	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
265	BIT(IIO_CHAN_INFO_INT_TIME) \|
266	BIT(IIO_CHAN_INFO_SCALE) \|
267	BIT(IIO_CHAN_INFO_HARDWAREGAIN),
268	}, {
269	.type = IIO_DISTANCE,
270	.address = VL6180_RANGE,
271	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \|
272	BIT(IIO_CHAN_INFO_SCALE),
273	}, {
274	.type = IIO_PROXIMITY,
275	.address = VL6180_PROX,
276	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
277	}
278	};
279
280	/*
e794bf67 SB	281	* Available Ambient Light Sensor gain settings, 1/1000th, and
e794bf67 SB	282	* corresponding setting for the VL6180_ALS_GAIN register
5e7f47e4	283	*/
e794bf67 SB	284	static const int vl6180_als_gain_tab[8] = {
	285	1000, 1250, 1670, 2500, 5000, 10000, 20000, 40000
	286	};
	287	static const u8 vl6180_als_gain_tab_bits[8] = {
	288	VL6180_ALS_GAIN_1, VL6180_ALS_GAIN_1_25,
	289	VL6180_ALS_GAIN_1_67, VL6180_ALS_GAIN_2_5,
	290	VL6180_ALS_GAIN_5, VL6180_ALS_GAIN_10,
	291	VL6180_ALS_GAIN_20, VL6180_ALS_GAIN_40
5e7f47e4 MS	292	};
	293
	294	static int vl6180_read_raw(struct iio_dev *indio_dev,
	295	struct iio_chan_spec const *chan,
	296	int val, int val2, long mask)
	297	{
	298	struct vl6180_data *data = iio_priv(indio_dev);
e794bf67	299	int ret;
5e7f47e4 MS	300
	301	switch (mask) {
	302	case IIO_CHAN_INFO_RAW:
	303	ret = vl6180_measure(data, chan->address);
	304	if (ret < 0)
	305	return ret;
	306	*val = ret;
	307
	308	return IIO_VAL_INT;
	309	case IIO_CHAN_INFO_INT_TIME:
df698c04 SB	310	*val = data->als_it_ms;
	311	*val2 = 1000;
	312
	313	return IIO_VAL_FRACTIONAL;
5e7f47e4	314
5e7f47e4 MS	315	case IIO_CHAN_INFO_SCALE:
	316	switch (chan->type) {
	317	case IIO_LIGHT:
3525d7cf SB	318	/* one ALS count is 0.32 Lux @ gain 1, IT 100 ms */
	319	val = 32000; / 0.32 * 1000 * 100 */
	320	val2 = data->als_gain_milli data->als_it_ms;
	321
	322	return IIO_VAL_FRACTIONAL;
	323
5e7f47e4 MS	324	case IIO_DISTANCE:
	325	val = 0; / sensor reports mm, scale to meter */
	326	*val2 = 1000;
	327	break;
	328	default:
	329	return -EINVAL;
	330	}
	331
	332	return IIO_VAL_INT_PLUS_MICRO;
	333	case IIO_CHAN_INFO_HARDWAREGAIN:
e794bf67 SB	334	*val = data->als_gain_milli;
	335	*val2 = 1000;
	336
	337	return IIO_VAL_FRACTIONAL;
5e7f47e4	338
5e7f47e4 MS	339	default:
	340	return -EINVAL;
	341	}
	342	}
	343
	344	static IIO_CONST_ATTR(als_gain_available, "1 1.25 1.67 2.5 5 10 20 40");
	345
	346	static struct attribute *vl6180_attributes[] = {
	347	&iio_const_attr_als_gain_available.dev_attr.attr,
	348	NULL
	349	};
	350
	351	static const struct attribute_group vl6180_attribute_group = {
	352	.attrs = vl6180_attributes,
	353	};
	354
	355	/* HOLD is needed before updating any config registers */
	356	static int vl6180_hold(struct vl6180_data *data, bool hold)
	357	{
	358	return vl6180_write_byte(data->client, VL6180_HOLD,
	359	hold ? VL6180_HOLD_ON : 0);
	360	}
	361
	362	static int vl6180_set_als_gain(struct vl6180_data *data, int val, int val2)
	363	{
e794bf67 SB	364	int i, ret, gain;
	365
	366	if (val < 1 \|\| val > 40)
	367	return -EINVAL;
5e7f47e4	368
e794bf67 SB	369	gain = (val * 1000000 + val2) / 1000;
	370	if (gain < 1 \|\| gain > 40000)
	371	return -EINVAL;
	372
	373	i = find_closest(gain, vl6180_als_gain_tab,
	374	ARRAY_SIZE(vl6180_als_gain_tab));
	375
	376	mutex_lock(&data->lock);
	377	ret = vl6180_hold(data, true);
	378	if (ret < 0)
	379	goto fail;
	380
	381	ret = vl6180_write_byte(data->client, VL6180_ALS_GAIN,
	382	vl6180_als_gain_tab_bits[i]);
	383
	384	if (ret >= 0)
	385	data->als_gain_milli = vl6180_als_gain_tab[i];
	386
	387	fail:
	388	vl6180_hold(data, false);
	389	mutex_unlock(&data->lock);
	390	return ret;
5e7f47e4 MS	391	}
5e7f47e4 MS	392
1e2ed3d0	393	static int vl6180_set_it(struct vl6180_data *data, int val, int val2)
5e7f47e4	394	{
1e2ed3d0 SB	395	int ret, it_ms;
	396
	397	it_ms = (val2 + 500) / 1000; /* round to ms */
	398	if (val != 0 \|\| it_ms < 1 \|\| it_ms > 512)
	399	return -EINVAL;
5e7f47e4 MS	400
	401	mutex_lock(&data->lock);
	402	ret = vl6180_hold(data, true);
	403	if (ret < 0)
	404	goto fail;
1e2ed3d0 SB	405
	406	ret = vl6180_write_word(data->client, VL6180_ALS_IT, it_ms - 1);
	407
df698c04 SB	408	if (ret >= 0)
	409	data->als_it_ms = it_ms;
	410
5e7f47e4 MS	411	fail:
	412	vl6180_hold(data, false);
	413	mutex_unlock(&data->lock);
	414
	415	return ret;
	416	}
	417
	418	static int vl6180_write_raw(struct iio_dev *indio_dev,
	419	struct iio_chan_spec const *chan,
	420	int val, int val2, long mask)
	421	{
	422	struct vl6180_data *data = iio_priv(indio_dev);
	423
	424	switch (mask) {
	425	case IIO_CHAN_INFO_INT_TIME:
1e2ed3d0	426	return vl6180_set_it(data, val, val2);
5e7f47e4	427
5e7f47e4 MS	428	case IIO_CHAN_INFO_HARDWAREGAIN:
	429	if (chan->type != IIO_LIGHT)
	430	return -EINVAL;
	431
	432	return vl6180_set_als_gain(data, val, val2);
	433	default:
	434	return -EINVAL;
	435	}
	436	}
	437
	438	static const struct iio_info vl6180_info = {
	439	.read_raw = vl6180_read_raw,
	440	.write_raw = vl6180_write_raw,
	441	.attrs = &vl6180_attribute_group,
5e7f47e4 MS	442	};
	443
	444	static int vl6180_init(struct vl6180_data *data)
	445	{
	446	struct i2c_client *client = data->client;
	447	int ret;
	448
	449	ret = vl6180_read_byte(client, VL6180_MODEL_ID);
	450	if (ret < 0)
	451	return ret;
	452
	453	if (ret != VL6180_MODEL_ID_VAL) {
	454	dev_err(&client->dev, "invalid model ID %02x\n", ret);
	455	return -ENODEV;
	456	}
	457
	458	ret = vl6180_hold(data, true);
	459	if (ret < 0)
	460	return ret;
	461
	462	ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET);
	463	if (ret < 0)
	464	return ret;
	465
	466	/*
	467	* Detect false reset condition here. This bit is always set when the
	468	* system comes out of reset.
	469	*/
	470	if (ret != 0x01)
	471	dev_info(&client->dev, "device is not fresh out of reset\n");
	472
	473	/* Enable ALS and Range ready interrupts */
	474	ret = vl6180_write_byte(client, VL6180_INTR_CONFIG,
	475	VL6180_ALS_READY \| VL6180_RANGE_READY);
	476	if (ret < 0)
	477	return ret;
	478
	479	/* ALS integration time: 100ms */
df698c04	480	data->als_it_ms = 100;
5e7f47e4 MS	481	ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
	482	if (ret < 0)
	483	return ret;
	484
	485	/* ALS gain: 1 */
e794bf67	486	data->als_gain_milli = 1000;
5e7f47e4 MS	487	ret = vl6180_write_byte(client, VL6180_ALS_GAIN, VL6180_ALS_GAIN_1);
	488	if (ret < 0)
	489	return ret;
	490
	491	ret = vl6180_write_byte(client, VL6180_OUT_OF_RESET, 0x00);
	492	if (ret < 0)
	493	return ret;
	494
	495	return vl6180_hold(data, false);
	496	}
	497
	498	static int vl6180_probe(struct i2c_client *client,
	499	const struct i2c_device_id *id)
	500	{
	501	struct vl6180_data *data;
	502	struct iio_dev *indio_dev;
	503	int ret;
	504
	505	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
	506	if (!indio_dev)
	507	return -ENOMEM;
	508
	509	data = iio_priv(indio_dev);
	510	i2c_set_clientdata(client, indio_dev);
	511	data->client = client;
	512	mutex_init(&data->lock);
	513
	514	indio_dev->dev.parent = &client->dev;
	515	indio_dev->info = &vl6180_info;
	516	indio_dev->channels = vl6180_channels;
	517	indio_dev->num_channels = ARRAY_SIZE(vl6180_channels);
	518	indio_dev->name = VL6180_DRV_NAME;
	519	indio_dev->modes = INDIO_DIRECT_MODE;
	520
	521	ret = vl6180_init(data);
	522	if (ret < 0)
	523	return ret;
	524
	525	return devm_iio_device_register(&client->dev, indio_dev);
	526	}
	527
	528	static const struct of_device_id vl6180_of_match[] = {
	529	{ .compatible = "st,vl6180", },
	530	{ },
	531	};
	532	MODULE_DEVICE_TABLE(of, vl6180_of_match);
	533
	534	static const struct i2c_device_id vl6180_id[] = {
	535	{ "vl6180", 0 },
	536	{ }
	537	};
	538	MODULE_DEVICE_TABLE(i2c, vl6180_id);
	539
	540	static struct i2c_driver vl6180_driver = {
	541	.driver = {
	542	.name = VL6180_DRV_NAME,
	543	.of_match_table = of_match_ptr(vl6180_of_match),
	544	},
	545	.probe = vl6180_probe,
	546	.id_table = vl6180_id,
	547	};
	548
	549	module_i2c_driver(vl6180_driver);
	550
551	MODULE_AUTHOR("Peter Meerwald-Stadler <pmeerw@pmeerw.net>");
552	MODULE_AUTHOR("Manivannan Sadhasivam <manivannanece23@gmail.com>");
553	MODULE_DESCRIPTION("STMicro VL6180 ALS, range and proximity sensor driver");
554	MODULE_LICENSE("GPL");