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280 lines
6.4 KiB
280 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Freescale MMA7660FC 3-Axis Accelerometer |
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* |
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* Copyright (c) 2016, Intel Corporation. |
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* |
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* IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c. |
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*/ |
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#include <linux/acpi.h> |
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#include <linux/i2c.h> |
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#include <linux/module.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#define MMA7660_DRIVER_NAME "mma7660" |
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#define MMA7660_REG_XOUT 0x00 |
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#define MMA7660_REG_YOUT 0x01 |
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#define MMA7660_REG_ZOUT 0x02 |
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#define MMA7660_REG_OUT_BIT_ALERT BIT(6) |
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#define MMA7660_REG_MODE 0x07 |
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#define MMA7660_REG_MODE_BIT_MODE BIT(0) |
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#define MMA7660_REG_MODE_BIT_TON BIT(2) |
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#define MMA7660_I2C_READ_RETRIES 5 |
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/* |
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* The accelerometer has one measurement range: |
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* |
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* -1.5g - +1.5g (6-bit, signed) |
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* |
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* scale = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857 |
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*/ |
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#define MMA7660_SCALE_AVAIL "0.467142857" |
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static const int mma7660_nscale = 467142857; |
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#define MMA7660_CHANNEL(reg, axis) { \ |
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.type = IIO_ACCEL, \ |
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.address = reg, \ |
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.modified = 1, \ |
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.channel2 = IIO_MOD_##axis, \ |
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
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} |
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static const struct iio_chan_spec mma7660_channels[] = { |
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MMA7660_CHANNEL(MMA7660_REG_XOUT, X), |
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MMA7660_CHANNEL(MMA7660_REG_YOUT, Y), |
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MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z), |
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}; |
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enum mma7660_mode { |
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MMA7660_MODE_STANDBY, |
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MMA7660_MODE_ACTIVE |
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}; |
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struct mma7660_data { |
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struct i2c_client *client; |
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struct mutex lock; |
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enum mma7660_mode mode; |
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}; |
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static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL); |
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static struct attribute *mma7660_attributes[] = { |
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&iio_const_attr_in_accel_scale_available.dev_attr.attr, |
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NULL, |
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}; |
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static const struct attribute_group mma7660_attribute_group = { |
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.attrs = mma7660_attributes |
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}; |
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static int mma7660_set_mode(struct mma7660_data *data, |
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enum mma7660_mode mode) |
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{ |
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int ret; |
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struct i2c_client *client = data->client; |
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if (mode == data->mode) |
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return 0; |
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ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE); |
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if (ret < 0) { |
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dev_err(&client->dev, "failed to read sensor mode\n"); |
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return ret; |
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} |
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if (mode == MMA7660_MODE_ACTIVE) { |
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ret &= ~MMA7660_REG_MODE_BIT_TON; |
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ret |= MMA7660_REG_MODE_BIT_MODE; |
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} else { |
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ret &= ~MMA7660_REG_MODE_BIT_TON; |
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ret &= ~MMA7660_REG_MODE_BIT_MODE; |
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} |
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ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret); |
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if (ret < 0) { |
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dev_err(&client->dev, "failed to change sensor mode\n"); |
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return ret; |
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} |
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data->mode = mode; |
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return ret; |
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} |
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static int mma7660_read_accel(struct mma7660_data *data, u8 address) |
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{ |
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int ret, retries = MMA7660_I2C_READ_RETRIES; |
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struct i2c_client *client = data->client; |
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/* |
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* Read data. If the Alert bit is set, the register was read at |
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* the same time as the device was attempting to update the content. |
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* The solution is to read the register again. Do this only |
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* MMA7660_I2C_READ_RETRIES times to avoid spending too much time |
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* in the kernel. |
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*/ |
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do { |
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ret = i2c_smbus_read_byte_data(client, address); |
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if (ret < 0) { |
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dev_err(&client->dev, "register read failed\n"); |
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return ret; |
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} |
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} while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT); |
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if (ret & MMA7660_REG_OUT_BIT_ALERT) { |
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dev_err(&client->dev, "all register read retries failed\n"); |
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return -ETIMEDOUT; |
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} |
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return ret; |
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} |
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static int mma7660_read_raw(struct iio_dev *indio_dev, |
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struct iio_chan_spec const *chan, |
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int *val, int *val2, long mask) |
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{ |
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struct mma7660_data *data = iio_priv(indio_dev); |
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int ret; |
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switch (mask) { |
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case IIO_CHAN_INFO_RAW: |
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mutex_lock(&data->lock); |
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ret = mma7660_read_accel(data, chan->address); |
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mutex_unlock(&data->lock); |
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if (ret < 0) |
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return ret; |
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*val = sign_extend32(ret, 5); |
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return IIO_VAL_INT; |
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case IIO_CHAN_INFO_SCALE: |
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*val = 0; |
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*val2 = mma7660_nscale; |
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return IIO_VAL_INT_PLUS_NANO; |
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default: |
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return -EINVAL; |
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} |
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return -EINVAL; |
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} |
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static const struct iio_info mma7660_info = { |
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.read_raw = mma7660_read_raw, |
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.attrs = &mma7660_attribute_group, |
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}; |
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static int mma7660_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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int ret; |
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struct iio_dev *indio_dev; |
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struct mma7660_data *data; |
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indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); |
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if (!indio_dev) { |
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dev_err(&client->dev, "iio allocation failed!\n"); |
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return -ENOMEM; |
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} |
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data = iio_priv(indio_dev); |
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data->client = client; |
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i2c_set_clientdata(client, indio_dev); |
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mutex_init(&data->lock); |
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data->mode = MMA7660_MODE_STANDBY; |
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indio_dev->info = &mma7660_info; |
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indio_dev->name = MMA7660_DRIVER_NAME; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = mma7660_channels; |
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indio_dev->num_channels = ARRAY_SIZE(mma7660_channels); |
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ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE); |
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if (ret < 0) |
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return ret; |
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ret = iio_device_register(indio_dev); |
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if (ret < 0) { |
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dev_err(&client->dev, "device_register failed\n"); |
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mma7660_set_mode(data, MMA7660_MODE_STANDBY); |
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} |
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return ret; |
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} |
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static int mma7660_remove(struct i2c_client *client) |
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{ |
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struct iio_dev *indio_dev = i2c_get_clientdata(client); |
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iio_device_unregister(indio_dev); |
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return mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY); |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int mma7660_suspend(struct device *dev) |
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{ |
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struct mma7660_data *data; |
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data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); |
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return mma7660_set_mode(data, MMA7660_MODE_STANDBY); |
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} |
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static int mma7660_resume(struct device *dev) |
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{ |
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struct mma7660_data *data; |
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data = iio_priv(i2c_get_clientdata(to_i2c_client(dev))); |
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return mma7660_set_mode(data, MMA7660_MODE_ACTIVE); |
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} |
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static SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend, mma7660_resume); |
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#define MMA7660_PM_OPS (&mma7660_pm_ops) |
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#else |
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#define MMA7660_PM_OPS NULL |
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#endif |
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static const struct i2c_device_id mma7660_i2c_id[] = { |
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{"mma7660", 0}, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id); |
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static const struct of_device_id mma7660_of_match[] = { |
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{ .compatible = "fsl,mma7660" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, mma7660_of_match); |
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static const struct acpi_device_id mma7660_acpi_id[] = { |
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{"MMA7660", 0}, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id); |
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static struct i2c_driver mma7660_driver = { |
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.driver = { |
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.name = "mma7660", |
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.pm = MMA7660_PM_OPS, |
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.of_match_table = mma7660_of_match, |
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.acpi_match_table = ACPI_PTR(mma7660_acpi_id), |
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}, |
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.probe = mma7660_probe, |
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.remove = mma7660_remove, |
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.id_table = mma7660_i2c_id, |
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}; |
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module_i2c_driver(mma7660_driver); |
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MODULE_AUTHOR("Constantin Musca <[email protected]>"); |
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MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver"); |
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MODULE_LICENSE("GPL v2");
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