| /** |
| * 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_I2C_READ_RETRIES 5 |
| |
| /* |
| * The accelerometer has one measurement range: |
| * |
| * -1.5g - +1.5g (6-bit, signed) |
| * |
| * scale = (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), |
| }; |
| |
| enum mma7660_mode { |
| MMA7660_MODE_STANDBY, |
| MMA7660_MODE_ACTIVE |
| }; |
| |
| struct mma7660_data { |
| struct i2c_client *client; |
| struct mutex lock; |
| enum mma7660_mode 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, |
| enum mma7660_mode mode) |
| { |
| int ret; |
| struct i2c_client *client = data->client; |
| |
| 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 read 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; |
| |
| /* |
| * Read data. If the Alert bit is set, the register was read at |
| * the same time as the device was attempting to update the content. |
| * The solution is to read the register again. Do this only |
| * MMA7660_I2C_READ_RETRIES times to avoid spending too much time |
| * in the kernel. |
| */ |
| 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 (ret & MMA7660_REG_OUT_BIT_ALERT) { |
| dev_err(&client->dev, "all register read retries failed\n"); |
| 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; |
| |
| 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_NANO; |
| 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 = 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); |
| mutex_init(&data->lock); |
| data->mode = MMA7660_MODE_STANDBY; |
| |
| 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@intel.com>"); |
| MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver"); |
| MODULE_LICENSE("GPL v2"); |