max44000: Initial support (b9567e66) · Commits · e / devices / android_kernel_teracube_2e

drivers/iio/light/Kconfig

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		@@ -234,6 +234,17 @@ config LTR501
		This driver can also be built as a module. If so, the module
		will be called ltr501.

		config MAX44000
		tristate "MAX44000 Ambient and Infrared Proximity Sensor"
		depends on I2C
		select REGMAP_I2C
		help
		Say Y here if you want to build support for Maxim Integrated's
		MAX44000 ambient and infrared proximity sensor device.

		To compile this driver as a module, choose M here:
		the module will be called max44000.

		config OPT3001
		tristate "Texas Instruments OPT3001 Light Sensor"
		depends on I2C

drivers/iio/light/Makefile

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		@@ -21,6 +21,7 @@ obj-$(CONFIG_ISL29125) += isl29125.o
		obj-$(CONFIG_JSA1212) += jsa1212.o
		obj-$(CONFIG_SENSORS_LM3533) += lm3533-als.o
		obj-$(CONFIG_LTR501) += ltr501.o
		obj-$(CONFIG_MAX44000) += max44000.o
		obj-$(CONFIG_OPT3001) += opt3001.o
		obj-$(CONFIG_PA12203001) += pa12203001.o
		obj-$(CONFIG_RPR0521) += rpr0521.o

drivers/iio/light/max44000.c

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+324 −0

Original line number	Diff line number	Diff line
		/*
		* MAX44000 Ambient and Infrared Proximity Sensor
		*
		* Copyright (c) 2016, Intel Corporation.
		*
		* 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.
		*
		* Data sheet: https://datasheets.maximintegrated.com/en/ds/MAX44000.pdf
		*
		* 7-bit I2C slave address 0x4a
		*/

		#include <linux/module.h>
		#include <linux/init.h>
		#include <linux/i2c.h>
		#include <linux/regmap.h>
		#include <linux/util_macros.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>
		#include <linux/acpi.h>

		#define MAX44000_DRV_NAME "max44000"

		/* Registers in datasheet order */
		#define MAX44000_REG_STATUS 0x00
		#define MAX44000_REG_CFG_MAIN 0x01
		#define MAX44000_REG_CFG_RX 0x02
		#define MAX44000_REG_CFG_TX 0x03
		#define MAX44000_REG_ALS_DATA_HI 0x04
		#define MAX44000_REG_ALS_DATA_LO 0x05
		#define MAX44000_REG_PRX_DATA 0x16
		#define MAX44000_REG_ALS_UPTHR_HI 0x06
		#define MAX44000_REG_ALS_UPTHR_LO 0x07
		#define MAX44000_REG_ALS_LOTHR_HI 0x08
		#define MAX44000_REG_ALS_LOTHR_LO 0x09
		#define MAX44000_REG_PST 0x0a
		#define MAX44000_REG_PRX_IND 0x0b
		#define MAX44000_REG_PRX_THR 0x0c
		#define MAX44000_REG_TRIM_GAIN_GREEN 0x0f
		#define MAX44000_REG_TRIM_GAIN_IR 0x10

		/* REG_CFG bits */
		#define MAX44000_CFG_ALSINTE 0x01
		#define MAX44000_CFG_PRXINTE 0x02
		#define MAX44000_CFG_MASK 0x1c
		#define MAX44000_CFG_MODE_SHUTDOWN 0x00
		#define MAX44000_CFG_MODE_ALS_GIR 0x04
		#define MAX44000_CFG_MODE_ALS_G 0x08
		#define MAX44000_CFG_MODE_ALS_IR 0x0c
		#define MAX44000_CFG_MODE_ALS_PRX 0x10
		#define MAX44000_CFG_MODE_PRX 0x14
		#define MAX44000_CFG_TRIM 0x20

		/*
		* Upper 4 bits are not documented but start as 1 on powerup
		* Setting them to 0 causes proximity to misbehave so set them to 1
		*/
		#define MAX44000_REG_CFG_RX_DEFAULT 0xf0

		#define MAX44000_ALSDATA_OVERFLOW 0x4000

		struct max44000_data {
		struct mutex lock;
		struct regmap *regmap;
		};

		/* Default scale is set to the minimum of 0.03125 or 1 / (1 << 5) lux */
		#define MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2 5

		static const struct iio_chan_spec max44000_channels[] = {
		{
		.type = IIO_LIGHT,
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
		},
		};

		static int max44000_read_alsval(struct max44000_data *data)
		{
		u16 regval;
		int ret;

		ret = regmap_bulk_read(data->regmap, MAX44000_REG_ALS_DATA_HI,
		&regval, sizeof(regval));
		if (ret < 0)
		return ret;

		regval = be16_to_cpu(regval);

		/*
		* Overflow is explained on datasheet page 17.
		*
		* It's a warning that either the G or IR channel has become saturated
		* and that the value in the register is likely incorrect.
		*
		* The recommendation is to change the scale (ALSPGA).
		* The driver just returns the max representable value.
		*/
		if (regval & MAX44000_ALSDATA_OVERFLOW)
		return 0x3FFF;

		return regval;
		}

		static int max44000_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct max44000_data *data = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		switch (chan->type) {
		case IIO_LIGHT:
		mutex_lock(&data->lock);
		ret = max44000_read_alsval(data);
		mutex_unlock(&data->lock);
		if (ret < 0)
		return ret;
		*val = ret;
		return IIO_VAL_INT;

		default:
		return -EINVAL;
		}

		case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_LIGHT:
		*val = 1;
		*val2 = MAX44000_ALS_TO_LUX_DEFAULT_FRACTION_LOG2;
		return IIO_VAL_FRACTIONAL_LOG2;

		default:
		return -EINVAL;
		}

		default:
		return -EINVAL;
		}
		}

		static const struct iio_info max44000_info = {
		.driver_module = THIS_MODULE,
		.read_raw = max44000_read_raw,
		};

		static bool max44000_readable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case MAX44000_REG_STATUS:
		case MAX44000_REG_CFG_MAIN:
		case MAX44000_REG_CFG_RX:
		case MAX44000_REG_CFG_TX:
		case MAX44000_REG_ALS_DATA_HI:
		case MAX44000_REG_ALS_DATA_LO:
		case MAX44000_REG_PRX_DATA:
		case MAX44000_REG_ALS_UPTHR_HI:
		case MAX44000_REG_ALS_UPTHR_LO:
		case MAX44000_REG_ALS_LOTHR_HI:
		case MAX44000_REG_ALS_LOTHR_LO:
		case MAX44000_REG_PST:
		case MAX44000_REG_PRX_IND:
		case MAX44000_REG_PRX_THR:
		case MAX44000_REG_TRIM_GAIN_GREEN:
		case MAX44000_REG_TRIM_GAIN_IR:
		return true;
		default:
		return false;
		}
		}

		static bool max44000_writeable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case MAX44000_REG_CFG_MAIN:
		case MAX44000_REG_CFG_RX:
		case MAX44000_REG_CFG_TX:
		case MAX44000_REG_ALS_UPTHR_HI:
		case MAX44000_REG_ALS_UPTHR_LO:
		case MAX44000_REG_ALS_LOTHR_HI:
		case MAX44000_REG_ALS_LOTHR_LO:
		case MAX44000_REG_PST:
		case MAX44000_REG_PRX_IND:
		case MAX44000_REG_PRX_THR:
		case MAX44000_REG_TRIM_GAIN_GREEN:
		case MAX44000_REG_TRIM_GAIN_IR:
		return true;
		default:
		return false;
		}
		}

		static bool max44000_volatile_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case MAX44000_REG_STATUS:
		case MAX44000_REG_ALS_DATA_HI:
		case MAX44000_REG_ALS_DATA_LO:
		case MAX44000_REG_PRX_DATA:
		return true;
		default:
		return false;
		}
		}

		static bool max44000_precious_reg(struct device *dev, unsigned int reg)
		{
		return reg == MAX44000_REG_STATUS;
		}

		static const struct regmap_config max44000_regmap_config = {
		.reg_bits = 8,
		.val_bits = 8,

		.max_register = MAX44000_REG_PRX_DATA,
		.readable_reg = max44000_readable_reg,
		.writeable_reg = max44000_writeable_reg,
		.volatile_reg = max44000_volatile_reg,
		.precious_reg = max44000_precious_reg,

		.use_single_rw = 1,
		.cache_type = REGCACHE_RBTREE,
		};

		static int max44000_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct max44000_data *data;
		struct iio_dev *indio_dev;
		int ret, reg;

		indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
		if (!indio_dev)
		return -ENOMEM;
		data = iio_priv(indio_dev);
		data->regmap = devm_regmap_init_i2c(client, &max44000_regmap_config);
		if (IS_ERR(data->regmap)) {
		dev_err(&client->dev, "regmap_init failed!\n");
		return PTR_ERR(data->regmap);
		}

		i2c_set_clientdata(client, indio_dev);
		mutex_init(&data->lock);
		indio_dev->dev.parent = &client->dev;
		indio_dev->info = &max44000_info;
		indio_dev->name = MAX44000_DRV_NAME;
		indio_dev->channels = max44000_channels;
		indio_dev->num_channels = ARRAY_SIZE(max44000_channels);

		/*
		* The device doesn't have a reset function so we just clear some
		* important bits at probe time to ensure sane operation.
		*
		* Since we don't support interrupts/events the threshold values are
		* not important. We also don't touch trim values.
		*/

		/* Reset ALS scaling bits */
		ret = regmap_write(data->regmap, MAX44000_REG_CFG_RX, MAX44000_REG_CFG_RX_DEFAULT);
		if (ret < 0) {
		dev_err(&client->dev, "failed to write default CFG_RX: %d\n", ret);
		return ret;
		}

		/* Reset CFG bits to ALS-only mode and no interrupts */
		reg = MAX44000_CFG_TRIM \| MAX44000_CFG_MODE_ALS_GIR;
		ret = regmap_write(data->regmap, MAX44000_REG_CFG_MAIN, reg);
		if (ret < 0) {
		dev_err(&client->dev, "failed to write init config: %d\n", ret);
		return ret;
		}

		/* Read status at least once to clear any stale interrupt bits. */
		ret = regmap_read(data->regmap, MAX44000_REG_STATUS, &reg);
		if (ret < 0) {
		dev_err(&client->dev, "failed to read init status: %d\n", ret);
		return ret;
		}

		return iio_device_register(indio_dev);
		}

		static int max44000_remove(struct i2c_client *client)
		{
		struct iio_dev *indio_dev = i2c_get_clientdata(client);

		iio_device_unregister(indio_dev);

		return 0;
		}

		static const struct i2c_device_id max44000_id[] = {
		{"max44000", 0},
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, max44000_id);

		#ifdef CONFIG_ACPI
		static const struct acpi_device_id max44000_acpi_match[] = {
		{"MAX44000", 0},
		{ }
		};
		MODULE_DEVICE_TABLE(acpi, max44000_acpi_match);
		#endif

		static struct i2c_driver max44000_driver = {
		.driver = {
		.name = MAX44000_DRV_NAME,
		.acpi_match_table = ACPI_PTR(max44000_acpi_match),
		},
		.probe = max44000_probe,
		.remove = max44000_remove,
		.id_table = max44000_id,
		};

		module_i2c_driver(max44000_driver);

		MODULE_AUTHOR("Crestez Dan Leonard <leonard.crestez@intel.com>");
		MODULE_DESCRIPTION("MAX44000 Ambient and Infrared Proximity Sensor");
		MODULE_LICENSE("GPL v2");