/* * 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, ®); 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 = { .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 & 0x1f) != 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[] = { {"MXC6225", 0}, {"MXC6255", 0}, { } }; MODULE_DEVICE_TABLE(acpi, mxc6255_acpi_match); static const struct i2c_device_id mxc6255_id[] = { {"mxc6225", 0}, {"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");