iio:light: Add support for STMicro VL6180 sensor (5e7f47e4) · Commits · e / devices / android_kernel_fairphone_FP4

Documentation/devicetree/bindings/iio/light/vl6180.txt

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		STMicro VL6180 - ALS, range and proximity sensor

		Link to datasheet: http://www.st.com/resource/en/datasheet/vl6180x.pdf

		Required properties:

		-compatible: should be "st,vl6180"
		-reg: the I2C address of the sensor

		Example:

		vl6180@29 {
		compatible = "st,vl6180";
		reg = <0x29>;
		};

drivers/iio/light/Kconfig

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		@@ -405,4 +405,14 @@ config VEML6070
		To compile this driver as a module, choose M here: the
		module will be called veml6070.

		config VL6180
		tristate "VL6180 ALS, range and proximity sensor"
		depends on I2C
		help
		Say Y here if you want to build a driver for the STMicroelectronics
		VL6180 combined ambient light, range and proximity sensor.

		To compile this driver as a module, choose M here: the
		module will be called vl6180.

		endmenu

drivers/iio/light/Makefile

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		@@ -38,3 +38,4 @@ obj-$(CONFIG_TSL4531) += tsl4531.o
		obj-$(CONFIG_US5182D) += us5182d.o
		obj-$(CONFIG_VCNL4000) += vcnl4000.o
		obj-$(CONFIG_VEML6070) += veml6070.o
		obj-$(CONFIG_VL6180) += vl6180.o

drivers/iio/light/vl6180.c

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		/*
		* 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/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;
		};

		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),
		}
		};

		/*
		* Columns 3 & 4 represent the same value in decimal and hex notations.
		* Kept in order to avoid the datatype conversion while reading the
		* hardware_gain.
		*/
		static const int vl6180_als_gain[8][4] = {
		{ 1, 0, 70, VL6180_ALS_GAIN_1 },
		{ 1, 250000, 69, VL6180_ALS_GAIN_1_25 },
		{ 1, 670000, 68, VL6180_ALS_GAIN_1_67 },
		{ 2, 500000, 67, VL6180_ALS_GAIN_2_5 },
		{ 5, 0, 66, VL6180_ALS_GAIN_5 },
		{ 10, 0, 65, VL6180_ALS_GAIN_10 },
		{ 20, 0, 64, VL6180_ALS_GAIN_20 },
		{ 40, 0, 71, 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, i;

		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:
		ret = vl6180_read_word(data->client, VL6180_ALS_IT);
		if (ret < 0)
		return ret;
		val = 0; / 1 count = 1ms (0 = 1ms) */
		val2 = (ret + 1) 1000; /* convert to seconds */

		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_LIGHT:
		val = 0; / one ALS count is 0.32 Lux */
		*val2 = 320000;
		break;
		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:
		ret = vl6180_read_byte(data->client, VL6180_ALS_GAIN);
		if (ret < 0)
		return -EINVAL;
		for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) {
		if (ret == vl6180_als_gain[i][2]) {
		*val = vl6180_als_gain[i][0];
		*val2 = vl6180_als_gain[i][1];
		}
		}

		return IIO_VAL_INT_PLUS_MICRO;
		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;

		for (i = 0; i < ARRAY_SIZE(vl6180_als_gain); i++) {
		if (val == vl6180_als_gain[i][0] &&
		val2 == vl6180_als_gain[i][1]) {
		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[i][3]);
		fail:
		vl6180_hold(data, false);
		mutex_unlock(&data->lock);
		return ret;
		}
		}

		return -EINVAL;
		}

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

		mutex_lock(&data->lock);
		ret = vl6180_hold(data, true);
		if (ret < 0)
		goto fail;
		ret = vl6180_write_word(data->client, VL6180_ALS_IT,
		(val2 - 500) / 1000); /* write value in 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:
		if (val != 0 \|\| val2 < 500 \|\| val2 >= 512500)
		return -EINVAL;

		return vl6180_set_it(data, 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,
		.driver_module = THIS_MODULE,
		};

		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 */
		ret = vl6180_write_word(client, VL6180_ALS_IT, VL6180_ALS_IT_100);
		if (ret < 0)
		return ret;

		/* ALS gain: 1 */
		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");