drivers/iio/accel/mc3230.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * mCube MC3230 3-Axis Accelerometer
 *
 * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
 *
 * IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>

#define MC3230_REG_XOUT			0x00
#define MC3230_REG_YOUT			0x01
#define MC3230_REG_ZOUT			0x02

#define MC3230_REG_MODE			0x07
#define MC3230_MODE_OPCON_MASK		0x03
#define MC3230_MODE_OPCON_WAKE		0x01
#define MC3230_MODE_OPCON_STANDBY	0x03

#define MC3230_REG_CHIP_ID		0x18
#define MC3230_REG_PRODUCT_CODE		0x3b

/*
 * The accelerometer has one measurement range:
 *
 * -1.5g - +1.5g (8-bit, signed)
 *
 */

struct mc3230_chip_info {
	const char *name;
	const u8 chip_id;
	const u8 product_code;
	const int scale;
};

static const struct mc3230_chip_info mc3230_chip_info = {
	.name = "mc3230",
	.chip_id = 0x01,
	.product_code = 0x19,
	/* (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765 */
	.scale = 115411765,
};

static const struct mc3230_chip_info mc3510c_chip_info = {
	.name = "mc3510c",
	.chip_id = 0x23,
	.product_code = 0x10,
	/* Was obtained empirically */
	.scale = 625000000,
};

#define MC3230_CHANNEL(reg, axis) {	\
	.type = IIO_ACCEL,	\
	.address = reg,	\
	.modified = 1,	\
	.channel2 = IIO_MOD_##axis,	\
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
	.ext_info = mc3230_ext_info, \
}

struct mc3230_data {
	const struct mc3230_chip_info *chip_info;
	struct i2c_client *client;
	struct iio_mount_matrix orientation;
};

static const struct iio_mount_matrix *
mc3230_get_mount_matrix(const struct iio_dev *indio_dev,
			const struct iio_chan_spec *chan)
{
	struct mc3230_data *data = iio_priv(indio_dev);

	return &data->orientation;
}

static const struct iio_chan_spec_ext_info mc3230_ext_info[] = {
	IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, mc3230_get_mount_matrix),
	{ }
};

static const struct iio_chan_spec mc3230_channels[] = {
	MC3230_CHANNEL(MC3230_REG_XOUT, X),
	MC3230_CHANNEL(MC3230_REG_YOUT, Y),
	MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
};

static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
{
	int ret;
	struct i2c_client *client = data->client;

	ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
	if (ret < 0) {
		dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
		return ret;
	}

	ret &= ~MC3230_MODE_OPCON_MASK;
	ret |= opcon;

	ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret);
	if (ret < 0) {
		dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
		return ret;
	}

	return 0;
}

static int mc3230_read_raw(struct iio_dev *indio_dev,
				struct iio_chan_spec const *chan,
				int *val, int *val2, long mask)
{
	struct mc3230_data *data = iio_priv(indio_dev);
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		ret = i2c_smbus_read_byte_data(data->client, chan->address);
		if (ret < 0)
			return ret;
		*val = sign_extend32(ret, 7);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = data->chip_info->scale;
		return IIO_VAL_INT_PLUS_NANO;
	default:
		return -EINVAL;
	}
}

static const struct iio_info mc3230_info = {
	.read_raw	= mc3230_read_raw,
};

static int mc3230_probe(struct i2c_client *client)
{
	int ret;
	struct iio_dev *indio_dev;
	struct mc3230_data *data;
	const struct mc3230_chip_info *chip_info;

	chip_info = i2c_get_match_data(client);
	if (chip_info == NULL) {
		dev_err(&client->dev, "failed to get match data");
		return -ENODATA;
	}

	/* First check chip-id and product-id */
	ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
	if (ret != chip_info->chip_id) {
		dev_info(&client->dev,
			"chip id check fail: 0x%x != 0x%x !\n",
			ret, chip_info->chip_id);
	}

	ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
	if (ret != chip_info->product_code) {
		dev_info(&client->dev,
			"product code check fail: 0x%x != 0x%x !\n",
			ret, chip_info->product_code);
	}

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

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

	indio_dev->info = &mc3230_info;
	indio_dev->name = chip_info->name;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = mc3230_channels;
	indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);

	ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
	if (ret < 0)
		return ret;

	ret = iio_read_mount_matrix(&client->dev, &data->orientation);
	if (ret)
		return ret;

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(&client->dev, "device_register failed\n");
		mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
	}

	return ret;
}

static void mc3230_remove(struct i2c_client *client)
{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	iio_device_unregister(indio_dev);

	mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
}

static int mc3230_suspend(struct device *dev)
{
	struct mc3230_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
}

static int mc3230_resume(struct device *dev)
{
	struct mc3230_data *data;

	data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));

	return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
}

static DEFINE_SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);

static const struct i2c_device_id mc3230_i2c_id[] = {
	{ "mc3230", (kernel_ulong_t)&mc3230_chip_info },
	{ "mc3510c", (kernel_ulong_t)&mc3510c_chip_info },
	{ }
};
MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);

static const struct of_device_id mc3230_of_match[] = {
	{ .compatible = "mcube,mc3230", &mc3230_chip_info },
	{ .compatible = "mcube,mc3510c", &mc3510c_chip_info },
	{ }
};
MODULE_DEVICE_TABLE(of, mc3230_of_match);

static struct i2c_driver mc3230_driver = {
	.driver = {
		.name = "mc3230",
		.of_match_table = mc3230_of_match,
		.pm = pm_sleep_ptr(&mc3230_pm_ops),
	},
	.probe		= mc3230_probe,
	.remove		= mc3230_remove,
	.id_table	= mc3230_i2c_id,
};

module_i2c_driver(mc3230_driver);

MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");