diff options
Diffstat (limited to 'drivers/iio/accel/mc3230.c')
| -rw-r--r-- | drivers/iio/accel/mc3230.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/drivers/iio/accel/mc3230.c b/drivers/iio/accel/mc3230.c new file mode 100644 index 0000000..4ea2ff6 --- /dev/null +++ b/drivers/iio/accel/mc3230.c @@ -0,0 +1,211 @@ +/** + * mCube MC3230 3-Axis Accelerometer + * + * Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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_CHIP_ID 0x01 + +#define MC3230_REG_PRODUCT_CODE 0x3b +#define MC3230_PRODUCT_CODE 0x19 + +/* + * The accelerometer has one measurement range: + * + * -1.5g - +1.5g (8-bit, signed) + * + * scale = (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765 + */ + +static const int mc3230_nscale = 115411765; + +#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), \ +} + +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), +}; + +struct mc3230_data { + struct i2c_client *client; +}; + +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 = mc3230_nscale; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } +} + +static const struct iio_info mc3230_info = { + .driver_module = THIS_MODULE, + .read_raw = mc3230_read_raw, +}; + +static int mc3230_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct iio_dev *indio_dev; + struct mc3230_data *data; + + /* First check chip-id and product-id */ + ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID); + if (ret != MC3230_CHIP_ID) + return (ret < 0) ? ret : -ENODEV; + + ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE); + if (ret != MC3230_PRODUCT_CODE) + return (ret < 0) ? ret : -ENODEV; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) { + dev_err(&client->dev, "iio allocation failed!\n"); + return -ENOMEM; + } + + data = iio_priv(indio_dev); + data->client = client; + i2c_set_clientdata(client, indio_dev); + + indio_dev->dev.parent = &client->dev; + indio_dev->info = &mc3230_info; + indio_dev->name = "mc3230"; + 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_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 int mc3230_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + + return mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY); +} + +#ifdef CONFIG_PM_SLEEP +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); +} +#endif + +static SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume); + +static const struct i2c_device_id mc3230_i2c_id[] = { + {"mc3230", 0}, + {} +}; +MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id); + +static struct i2c_driver mc3230_driver = { + .driver = { + .name = "mc3230", + .pm = &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"); |
