iio: accel: add support for Memsic MXC6255XC sensor (75b6548f) · Commits · e / devices / android_kernel_teracube_emerald

drivers/iio/accel/Kconfig

+11 −0

Original line number	Diff line number	Diff line
		@@ -158,6 +158,17 @@ config MXC4005
		To compile this driver as a module, choose M. The module will be
		called mxc4005.

		config MXC6255
		tristate "Memsic MXC6255 Orientation Sensing Accelerometer Driver"
		depends on I2C
		select REGMAP_I2C
		help
		Say yes here to build support for the Memsic MXC6255 Orientation
		Sensing Accelerometer Driver.

		To compile this driver as a module, choose M here: the module will be
		called mxc6255.

		config STK8312
		tristate "Sensortek STK8312 3-Axis Accelerometer Driver"
		depends on I2C

drivers/iio/accel/Makefile

+1 −0

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		@@ -17,6 +17,7 @@ obj-$(CONFIG_MMA9551) += mma9551.o
		obj-$(CONFIG_MMA9553) += mma9553.o

		obj-$(CONFIG_MXC4005) += mxc4005.o
		obj-$(CONFIG_MXC6255) += mxc6255.o

		obj-$(CONFIG_STK8312) += stk8312.o
		obj-$(CONFIG_STK8BA50) += stk8ba50.o

drivers/iio/accel/mxc6255.c

0 → 100644

+198 −0

Original line number	Diff line number	Diff line
		/*
		* MXC6255 - MEMSIC orientation sensing accelerometer
		*
		* Copyright (c) 2015, 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.
		*
		* IIO driver for MXC6255 (7-bit I2C slave address 0x15).
		*/

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

		#define MXC6255_DRV_NAME "mxc6255"
		#define MXC6255_REGMAP_NAME "mxc6255_regmap"

		#define MXC6255_REG_XOUT 0x00
		#define MXC6255_REG_YOUT 0x01
		#define MXC6255_REG_CHIP_ID 0x08

		#define MXC6255_CHIP_ID 0x05

		/*
		* MXC6255 has only one measurement range: +/- 2G.
		* The acceleration output is an 8-bit value.
		*
		* Scale is calculated as follows:
		* (2 + 2) * 9.80665 / (2^8 - 1) = 0.153829
		*
		* Scale value for +/- 2G measurement range
		*/
		#define MXC6255_SCALE 153829

		enum mxc6255_axis {
		AXIS_X,
		AXIS_Y,
		};

		struct mxc6255_data {
		struct i2c_client *client;
		struct regmap *regmap;
		};

		static int mxc6255_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct mxc6255_data *data = iio_priv(indio_dev);
		unsigned int reg;
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		ret = regmap_read(data->regmap, chan->address, &reg);
		if (ret < 0) {
		dev_err(&data->client->dev,
		"Error reading reg %lu\n", chan->address);
		return ret;
		}

		*val = sign_extend32(reg, 7);
		return IIO_VAL_INT;
		case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = MXC6255_SCALE;
		return IIO_VAL_INT_PLUS_MICRO;
		default:
		return -EINVAL;
		}
		}

		static const struct iio_info mxc6255_info = {
		.driver_module = THIS_MODULE,
		.read_raw = mxc6255_read_raw,
		};

		#define MXC6255_CHANNEL(_axis, reg) { \
		.type = IIO_ACCEL, \
		.modified = 1, \
		.channel2 = IIO_MOD_##_axis, \
		.address = reg, \
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
		}

		static const struct iio_chan_spec mxc6255_channels[] = {
		MXC6255_CHANNEL(X, MXC6255_REG_XOUT),
		MXC6255_CHANNEL(Y, MXC6255_REG_YOUT),
		};

		static bool mxc6255_is_readable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case MXC6255_REG_XOUT:
		case MXC6255_REG_YOUT:
		case MXC6255_REG_CHIP_ID:
		return true;
		default:
		return false;
		}
		}

		static const struct regmap_config mxc6255_regmap_config = {
		.name = MXC6255_REGMAP_NAME,

		.reg_bits = 8,
		.val_bits = 8,

		.readable_reg = mxc6255_is_readable_reg,
		};

		static int mxc6255_probe(struct i2c_client *client,
		const struct i2c_device_id *id)
		{
		struct mxc6255_data *data;
		struct iio_dev *indio_dev;
		struct regmap *regmap;
		unsigned int chip_id;
		int ret;

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

		regmap = devm_regmap_init_i2c(client, &mxc6255_regmap_config);
		if (IS_ERR(regmap)) {
		dev_err(&client->dev, "Error initializing regmap\n");
		return PTR_ERR(regmap);
		}

		data = iio_priv(indio_dev);
		i2c_set_clientdata(client, indio_dev);
		data->client = client;
		data->regmap = regmap;

		indio_dev->name = MXC6255_DRV_NAME;
		indio_dev->dev.parent = &client->dev;
		indio_dev->channels = mxc6255_channels;
		indio_dev->num_channels = ARRAY_SIZE(mxc6255_channels);
		indio_dev->modes = INDIO_DIRECT_MODE;
		indio_dev->info = &mxc6255_info;

		ret = regmap_read(data->regmap, MXC6255_REG_CHIP_ID, &chip_id);
		if (ret < 0) {
		dev_err(&client->dev, "Error reading chip id %d\n", ret);
		return ret;
		}

		if (chip_id != MXC6255_CHIP_ID) {
		dev_err(&client->dev, "Invalid chip id %x\n", chip_id);
		return -ENODEV;
		}

		dev_dbg(&client->dev, "Chip id %x\n", chip_id);

		ret = devm_iio_device_register(&client->dev, indio_dev);
		if (ret < 0) {
		dev_err(&client->dev, "Could not register IIO device\n");
		return ret;
		}

		return 0;
		}

		static const struct acpi_device_id mxc6255_acpi_match[] = {
		{"MXC6255", 0},
		{ }
		};
		MODULE_DEVICE_TABLE(acpi, mxc6255_acpi_match);

		static const struct i2c_device_id mxc6255_id[] = {
		{"mxc6255", 0},
		{ }
		};
		MODULE_DEVICE_TABLE(i2c, mxc6255_id);

		static struct i2c_driver mxc6255_driver = {
		.driver = {
		.name = MXC6255_DRV_NAME,
		.acpi_match_table = ACPI_PTR(mxc6255_acpi_match),
		},
		.probe = mxc6255_probe,
		.id_table = mxc6255_id,
		};

		module_i2c_driver(mxc6255_driver);

		MODULE_AUTHOR("Teodora Baluta <teodora.baluta@intel.com>");
		MODULE_DESCRIPTION("MEMSIC MXC6255 orientation sensing accelerometer driver");
		MODULE_LICENSE("GPL v2");