diff options
Diffstat (limited to 'drivers/iio/accel/da280.c')
| -rw-r--r-- | drivers/iio/accel/da280.c | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/drivers/iio/accel/da280.c b/drivers/iio/accel/da280.c new file mode 100644 index 000000000..d4b555203 --- /dev/null +++ b/drivers/iio/accel/da280.c @@ -0,0 +1,209 @@ +/** + * IIO driver for the MiraMEMS DA280 3-axis accelerometer and + * IIO driver for the MiraMEMS DA226 2-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 and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/acpi.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/byteorder/generic.h> + +#define DA280_REG_CHIP_ID 0x01 +#define DA280_REG_ACC_X_LSB 0x02 +#define DA280_REG_ACC_Y_LSB 0x04 +#define DA280_REG_ACC_Z_LSB 0x06 +#define DA280_REG_MODE_BW 0x11 + +#define DA280_CHIP_ID 0x13 +#define DA280_MODE_ENABLE 0x1e +#define DA280_MODE_DISABLE 0x9e + +enum da280_chipset { da226, da280 }; + +/* + * a value of + or -4096 corresponds to + or - 1G + * scale = 9.81 / 4096 = 0.002395019 + */ + +static const int da280_nscale = 2395019; + +#define DA280_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 da280_channels[] = { + DA280_CHANNEL(DA280_REG_ACC_X_LSB, X), + DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y), + DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z), +}; + +struct da280_data { + struct i2c_client *client; +}; + +static int da280_enable(struct i2c_client *client, bool enable) +{ + u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE; + + return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data); +} + +static int da280_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct da280_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = i2c_smbus_read_word_data(data->client, chan->address); + if (ret < 0) + return ret; + /* + * Values are 14 bits, stored as 16 bits with the 2 + * least significant bits always 0. + */ + *val = (short)ret >> 2; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = da280_nscale; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } +} + +static const struct iio_info da280_info = { + .read_raw = da280_read_raw, +}; + +static enum da280_chipset da280_match_acpi_device(struct device *dev) +{ + const struct acpi_device_id *id; + + id = acpi_match_device(dev->driver->acpi_match_table, dev); + if (!id) + return -EINVAL; + + return (enum da280_chipset) id->driver_data; +} + +static int da280_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct iio_dev *indio_dev; + struct da280_data *data; + enum da280_chipset chip; + + ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID); + if (ret != DA280_CHIP_ID) + return (ret < 0) ? ret : -ENODEV; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + 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 = &da280_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = da280_channels; + + if (ACPI_HANDLE(&client->dev)) { + chip = da280_match_acpi_device(&client->dev); + } else { + chip = id->driver_data; + } + + if (chip == da226) { + indio_dev->name = "da226"; + indio_dev->num_channels = 2; + } else { + indio_dev->name = "da280"; + indio_dev->num_channels = 3; + } + + ret = da280_enable(client, true); + if (ret < 0) + return ret; + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, "device_register failed\n"); + da280_enable(client, false); + } + + return ret; +} + +static int da280_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + + return da280_enable(client, false); +} + +#ifdef CONFIG_PM_SLEEP +static int da280_suspend(struct device *dev) +{ + return da280_enable(to_i2c_client(dev), false); +} + +static int da280_resume(struct device *dev) +{ + return da280_enable(to_i2c_client(dev), true); +} +#endif + +static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume); + +static const struct acpi_device_id da280_acpi_match[] = { + {"MIRAACC", da280}, + {}, +}; +MODULE_DEVICE_TABLE(acpi, da280_acpi_match); + +static const struct i2c_device_id da280_i2c_id[] = { + { "da226", da226 }, + { "da280", da280 }, + {} +}; +MODULE_DEVICE_TABLE(i2c, da280_i2c_id); + +static struct i2c_driver da280_driver = { + .driver = { + .name = "da280", + .acpi_match_table = ACPI_PTR(da280_acpi_match), + .pm = &da280_pm_ops, + }, + .probe = da280_probe, + .remove = da280_remove, + .id_table = da280_i2c_id, +}; + +module_i2c_driver(da280_driver); + +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver"); +MODULE_LICENSE("GPL v2"); |