Minimal implementation of an IIO driver for the Freescale MMA7660FC 3-axis accelerometer. Datasheet: http://www.freescale.com.cn/files/sensors/doc/data_sheet/MMA7660FC.pdf Includes: - ACPI support; - read_raw for x,y,z axes; - reading and setting the scale (range) parameter. - power management Signed-off-by: Constantin Musca <constantin.musca@xxxxxxxxx> --- drivers/iio/accel/Kconfig | 10 ++ drivers/iio/accel/Makefile | 2 + drivers/iio/accel/mma7660.c | 275 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 287 insertions(+) create mode 100644 drivers/iio/accel/mma7660.c diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig index e4a758c..2e6a0e6 100644 --- a/drivers/iio/accel/Kconfig +++ b/drivers/iio/accel/Kconfig @@ -54,6 +54,16 @@ config HID_SENSOR_ACCEL_3D To compile this driver as a module, choose M here: the module will be called hid-sensor-accel-3d. +config MMA7660 + tristate "Freescale MMA7660FC 3-Axis Accelerometer Driver" + depends on I2C + help + Say yes here to get support for the Freescale MMA7660FC 3-Axis + accelerometer. + + Choosing M will build the driver as a module. If so, the module + will be called mma7660. + config IIO_ST_ACCEL_3AXIS tristate "STMicroelectronics accelerometers 3-Axis Driver" depends on (I2C || SPI_MASTER) && SYSFS diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile index 71b6794..ba1165f 100644 --- a/drivers/iio/accel/Makefile +++ b/drivers/iio/accel/Makefile @@ -15,6 +15,8 @@ obj-$(CONFIG_MMA7455) += mma7455_core.o obj-$(CONFIG_MMA7455_I2C) += mma7455_i2c.o obj-$(CONFIG_MMA7455_SPI) += mma7455_spi.o +obj-$(CONFIG_MMA7660) += mma7660.o + obj-$(CONFIG_MMA8452) += mma8452.o obj-$(CONFIG_MMA9551_CORE) += mma9551_core.o diff --git a/drivers/iio/accel/mma7660.c b/drivers/iio/accel/mma7660.c new file mode 100644 index 0000000..9aad91d --- /dev/null +++ b/drivers/iio/accel/mma7660.c @@ -0,0 +1,275 @@ +/** + * Freescale MMA7660FC 3-Axis Accelerometer + * + * Copyright (c) 2016, 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 Freescale MMA7660FC; 7-bit I2C address: 0x4c. + */ + +#include <linux/acpi.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> + +#define MMA7660_DRIVER_NAME "mma7660" + +#define MMA7660_REG_XOUT 0x00 +#define MMA7660_REG_YOUT 0x01 +#define MMA7660_REG_ZOUT 0x02 +#define MMA7660_REG_OUT_BIT_ALERT BIT(6) + +#define MMA7660_REG_MODE 0x07 +#define MMA7660_REG_MODE_BIT_MODE BIT(0) +#define MMA7660_REG_MODE_BIT_TON BIT(2) + +#define MMA7660_MODE_STANDBY 0 +#define MMA7660_MODE_ACTIVE 1 + +#define MMA7660_I2C_READ_RETRIES 5 + +/* + * The accelerometer has one measurement range: + * + * -1.5g - +1.5g (6-bit, signed) + * + * scale1 = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857 + */ + +#define MMA7660_SCALE_AVAIL "0.467142857" + +const int mma7660_nscale = 467142857; + +#define MMA7660_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 mma7660_channels[] = { + MMA7660_CHANNEL(MMA7660_REG_XOUT, X), + MMA7660_CHANNEL(MMA7660_REG_YOUT, Y), + MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z), +}; + +struct mma7660_data { + struct i2c_client *client; + struct mutex lock; + u8 mode; +}; + +static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL); + +static struct attribute *mma7660_attributes[] = { + &iio_const_attr_in_accel_scale_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group mma7660_attribute_group = { + .attrs = mma7660_attributes +}; + +static int mma7660_set_mode(struct mma7660_data *data, u8 mode) +{ + int ret; + struct i2c_client *client = data->client; + + if (mode > 1) + return -EINVAL; + + if (mode == data->mode) + return 0; + + ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE); + if (ret < 0) { + dev_err(&client->dev, "failed to change sensor mode\n"); + return ret; + } + + if (mode == MMA7660_MODE_ACTIVE) { + ret &= ~MMA7660_REG_MODE_BIT_TON; + ret |= MMA7660_REG_MODE_BIT_MODE; + } else { + ret &= ~MMA7660_REG_MODE_BIT_TON; + ret &= ~MMA7660_REG_MODE_BIT_MODE; + } + + ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret); + if (ret < 0) { + dev_err(&client->dev, "failed to change sensor mode\n"); + return ret; + } + + data->mode = mode; + return ret; +} + +static int mma7660_read_accel(struct mma7660_data *data, u8 address) +{ + int ret, retries = MMA7660_I2C_READ_RETRIES; + struct i2c_client *client = data->client; + + if (address > 2) + return -EINVAL; + + do { + ret = i2c_smbus_read_byte_data(client, address); + if (ret < 0) { + dev_err(&client->dev, "register read failed\n"); + return ret; + } + } while (--retries > 0 && ret & MMA7660_REG_OUT_BIT_ALERT); + + if (retries == 0) { + dev_err(&client->dev, "all register read retries failed"); + return -ETIMEDOUT; + } + + return ret; +} + +static int mma7660_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct mma7660_data *data = iio_priv(indio_dev); + int ret; + + if (chan->type != IIO_ACCEL) + return -EINVAL; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + mutex_lock(&data->lock); + ret = mma7660_read_accel(data, chan->address); + mutex_unlock(&data->lock); + if (ret < 0) + return ret; + *val = sign_extend32(ret, 5); + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = mma7660_nscale; + return IIO_VAL_INT_PLUS_MICRO; + default: + return -EINVAL; + } + + return -EINVAL; +} + +static const struct iio_info mma7660_info = { + .driver_module = THIS_MODULE, + .read_raw = mma7660_read_raw, + .attrs = &mma7660_attribute_group, +}; + +static int mma7660_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int ret; + struct iio_dev *indio_dev; + struct mma7660_data *data; + + indio_dev = iio_device_alloc(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); + mutex_init(&data->lock); + data->mode = -1; + + indio_dev->dev.parent = &client->dev; + indio_dev->info = &mma7660_info; + indio_dev->name = MMA7660_DRIVER_NAME; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = mma7660_channels; + indio_dev->num_channels = ARRAY_SIZE(mma7660_channels); + + ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE); + if (ret < 0) + return ret; + + ret = iio_device_register(indio_dev); + if (ret < 0) { + dev_err(&client->dev, "device_register failed\n"); + mma7660_set_mode(data, MMA7660_MODE_STANDBY); + } + + return ret; +} + +static int mma7660_remove(struct i2c_client *client) +{ + struct iio_dev *indio_dev = i2c_get_clientdata(client); + + iio_device_unregister(indio_dev); + + return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY); +} + +#ifdef CONFIG_PM_SLEEP +static int mma7660_suspend(struct device *dev) +{ + struct mma7660_data *data; + + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + + return mma7660_set_mode(data, MMA7660_MODE_STANDBY); +} + +static int mma7660_resume(struct device *dev) +{ + struct mma7660_data *data; + + data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); + + return mma7660_set_mode(data, MMA7660_MODE_ACTIVE); +} + +static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume); + +#define MMA7660_PM_OPS (&mma7660_pm_ops) +#else +#define MMA7660_PM_OPS NULL +#endif + +static const struct i2c_device_id mma7660_i2c_id[] = { + {"MMA7660", 0}, + {} +}; + +static const struct acpi_device_id mma7660_acpi_id[] = { + {"MMA7660", 0}, + {} +}; + +MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id); + +static struct i2c_driver mma7660_driver = { + .driver = { + .name = "mma7660", + .pm = MMA7660_PM_OPS, + .acpi_match_table = ACPI_PTR(mma7660_acpi_id), + }, + .probe = mma7660_probe, + .remove = mma7660_remove, + .id_table = mma7660_i2c_id, +}; + +module_i2c_driver(mma7660_driver); + +MODULE_AUTHOR("Constantin Musca <constantin.musca@xxxxxxxxx>"); +MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
