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346 lines
8.1 KiB
346 lines
8.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* mpl3115.c - Support for Freescale MPL3115A2 pressure/temperature sensor |
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* |
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* Copyright (c) 2013 Peter Meerwald <[email protected]> |
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* |
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* (7-bit I2C slave address 0x60) |
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* |
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* TODO: FIFO buffer, altimeter mode, oversampling, continuous mode, |
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* interrupts, user offset correction, raw mode |
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*/ |
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#include <linux/module.h> |
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#include <linux/i2c.h> |
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#include <linux/iio/iio.h> |
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#include <linux/iio/sysfs.h> |
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#include <linux/iio/trigger_consumer.h> |
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#include <linux/iio/buffer.h> |
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#include <linux/iio/triggered_buffer.h> |
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#include <linux/delay.h> |
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#define MPL3115_STATUS 0x00 |
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#define MPL3115_OUT_PRESS 0x01 /* MSB first, 20 bit */ |
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#define MPL3115_OUT_TEMP 0x04 /* MSB first, 12 bit */ |
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#define MPL3115_WHO_AM_I 0x0c |
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#define MPL3115_CTRL_REG1 0x26 |
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#define MPL3115_DEVICE_ID 0xc4 |
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#define MPL3115_STATUS_PRESS_RDY BIT(2) |
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#define MPL3115_STATUS_TEMP_RDY BIT(1) |
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#define MPL3115_CTRL_RESET BIT(2) /* software reset */ |
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#define MPL3115_CTRL_OST BIT(1) /* initiate measurement */ |
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#define MPL3115_CTRL_ACTIVE BIT(0) /* continuous measurement */ |
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#define MPL3115_CTRL_OS_258MS (BIT(5) | BIT(4)) /* 64x oversampling */ |
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struct mpl3115_data { |
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struct i2c_client *client; |
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struct mutex lock; |
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u8 ctrl_reg1; |
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}; |
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static int mpl3115_request(struct mpl3115_data *data) |
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{ |
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int ret, tries = 15; |
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/* trigger measurement */ |
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ret = i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
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data->ctrl_reg1 | MPL3115_CTRL_OST); |
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if (ret < 0) |
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return ret; |
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while (tries-- > 0) { |
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ret = i2c_smbus_read_byte_data(data->client, MPL3115_CTRL_REG1); |
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if (ret < 0) |
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return ret; |
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/* wait for data ready, i.e. OST cleared */ |
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if (!(ret & MPL3115_CTRL_OST)) |
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break; |
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msleep(20); |
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} |
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if (tries < 0) { |
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dev_err(&data->client->dev, "data not ready\n"); |
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return -EIO; |
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} |
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return 0; |
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} |
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static int mpl3115_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 mpl3115_data *data = iio_priv(indio_dev); |
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__be32 tmp = 0; |
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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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ret = iio_device_claim_direct_mode(indio_dev); |
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if (ret) |
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return ret; |
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switch (chan->type) { |
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case IIO_PRESSURE: /* in 0.25 pascal / LSB */ |
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mutex_lock(&data->lock); |
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ret = mpl3115_request(data); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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break; |
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} |
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ret = i2c_smbus_read_i2c_block_data(data->client, |
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MPL3115_OUT_PRESS, 3, (u8 *) &tmp); |
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mutex_unlock(&data->lock); |
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if (ret < 0) |
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break; |
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*val = be32_to_cpu(tmp) >> 12; |
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ret = IIO_VAL_INT; |
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break; |
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case IIO_TEMP: /* in 0.0625 celsius / LSB */ |
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mutex_lock(&data->lock); |
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ret = mpl3115_request(data); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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break; |
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} |
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ret = i2c_smbus_read_i2c_block_data(data->client, |
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MPL3115_OUT_TEMP, 2, (u8 *) &tmp); |
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mutex_unlock(&data->lock); |
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if (ret < 0) |
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break; |
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*val = sign_extend32(be32_to_cpu(tmp) >> 20, 11); |
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ret = IIO_VAL_INT; |
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break; |
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default: |
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ret = -EINVAL; |
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break; |
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} |
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iio_device_release_direct_mode(indio_dev); |
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return ret; |
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case IIO_CHAN_INFO_SCALE: |
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switch (chan->type) { |
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case IIO_PRESSURE: |
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*val = 0; |
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*val2 = 250; /* want kilopascal */ |
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return IIO_VAL_INT_PLUS_MICRO; |
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case IIO_TEMP: |
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*val = 0; |
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*val2 = 62500; |
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return IIO_VAL_INT_PLUS_MICRO; |
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default: |
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return -EINVAL; |
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} |
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} |
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return -EINVAL; |
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} |
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static irqreturn_t mpl3115_trigger_handler(int irq, void *p) |
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{ |
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struct iio_poll_func *pf = p; |
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struct iio_dev *indio_dev = pf->indio_dev; |
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struct mpl3115_data *data = iio_priv(indio_dev); |
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/* |
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* 32-bit channel + 16-bit channel + padding + ts |
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* Note that it is possible for only one of the first 2 |
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* channels to be enabled. If that happens, the first element |
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* of the buffer may be either 16 or 32-bits. As such we cannot |
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* use a simple structure definition to express this data layout. |
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*/ |
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u8 buffer[16] __aligned(8); |
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int ret, pos = 0; |
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mutex_lock(&data->lock); |
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ret = mpl3115_request(data); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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goto done; |
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} |
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memset(buffer, 0, sizeof(buffer)); |
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if (test_bit(0, indio_dev->active_scan_mask)) { |
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ret = i2c_smbus_read_i2c_block_data(data->client, |
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MPL3115_OUT_PRESS, 3, &buffer[pos]); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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goto done; |
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} |
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pos += 4; |
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} |
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if (test_bit(1, indio_dev->active_scan_mask)) { |
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ret = i2c_smbus_read_i2c_block_data(data->client, |
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MPL3115_OUT_TEMP, 2, &buffer[pos]); |
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if (ret < 0) { |
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mutex_unlock(&data->lock); |
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goto done; |
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} |
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} |
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mutex_unlock(&data->lock); |
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iio_push_to_buffers_with_timestamp(indio_dev, buffer, |
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iio_get_time_ns(indio_dev)); |
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done: |
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iio_trigger_notify_done(indio_dev->trig); |
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return IRQ_HANDLED; |
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} |
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static const struct iio_chan_spec mpl3115_channels[] = { |
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{ |
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.type = IIO_PRESSURE, |
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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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.scan_index = 0, |
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.scan_type = { |
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.sign = 'u', |
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.realbits = 20, |
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.storagebits = 32, |
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.shift = 12, |
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.endianness = IIO_BE, |
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} |
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}, |
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{ |
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.type = IIO_TEMP, |
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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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.scan_index = 1, |
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.scan_type = { |
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.sign = 's', |
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.realbits = 12, |
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.storagebits = 16, |
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.shift = 4, |
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.endianness = IIO_BE, |
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} |
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}, |
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IIO_CHAN_SOFT_TIMESTAMP(2), |
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}; |
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static const struct iio_info mpl3115_info = { |
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.read_raw = &mpl3115_read_raw, |
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}; |
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static int mpl3115_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct mpl3115_data *data; |
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struct iio_dev *indio_dev; |
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int ret; |
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ret = i2c_smbus_read_byte_data(client, MPL3115_WHO_AM_I); |
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if (ret < 0) |
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return ret; |
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if (ret != MPL3115_DEVICE_ID) |
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return -ENODEV; |
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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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return -ENOMEM; |
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data = iio_priv(indio_dev); |
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data->client = client; |
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mutex_init(&data->lock); |
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i2c_set_clientdata(client, indio_dev); |
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indio_dev->info = &mpl3115_info; |
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indio_dev->name = id->name; |
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indio_dev->modes = INDIO_DIRECT_MODE; |
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indio_dev->channels = mpl3115_channels; |
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indio_dev->num_channels = ARRAY_SIZE(mpl3115_channels); |
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/* software reset, I2C transfer is aborted (fails) */ |
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i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, |
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MPL3115_CTRL_RESET); |
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msleep(50); |
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data->ctrl_reg1 = MPL3115_CTRL_OS_258MS; |
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ret = i2c_smbus_write_byte_data(client, MPL3115_CTRL_REG1, |
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data->ctrl_reg1); |
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if (ret < 0) |
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return ret; |
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ret = iio_triggered_buffer_setup(indio_dev, NULL, |
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mpl3115_trigger_handler, NULL); |
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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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goto buffer_cleanup; |
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return 0; |
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buffer_cleanup: |
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iio_triggered_buffer_cleanup(indio_dev); |
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return ret; |
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} |
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static int mpl3115_standby(struct mpl3115_data *data) |
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{ |
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return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
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data->ctrl_reg1 & ~MPL3115_CTRL_ACTIVE); |
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} |
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static int mpl3115_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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iio_triggered_buffer_cleanup(indio_dev); |
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mpl3115_standby(iio_priv(indio_dev)); |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int mpl3115_suspend(struct device *dev) |
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{ |
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return mpl3115_standby(iio_priv(i2c_get_clientdata( |
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to_i2c_client(dev)))); |
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} |
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static int mpl3115_resume(struct device *dev) |
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{ |
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struct mpl3115_data *data = iio_priv(i2c_get_clientdata( |
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to_i2c_client(dev))); |
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return i2c_smbus_write_byte_data(data->client, MPL3115_CTRL_REG1, |
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data->ctrl_reg1); |
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} |
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static SIMPLE_DEV_PM_OPS(mpl3115_pm_ops, mpl3115_suspend, mpl3115_resume); |
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#define MPL3115_PM_OPS (&mpl3115_pm_ops) |
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#else |
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#define MPL3115_PM_OPS NULL |
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#endif |
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static const struct i2c_device_id mpl3115_id[] = { |
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{ "mpl3115", 0 }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(i2c, mpl3115_id); |
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static const struct of_device_id mpl3115_of_match[] = { |
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{ .compatible = "fsl,mpl3115" }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(of, mpl3115_of_match); |
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static struct i2c_driver mpl3115_driver = { |
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.driver = { |
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.name = "mpl3115", |
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.of_match_table = mpl3115_of_match, |
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.pm = MPL3115_PM_OPS, |
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}, |
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.probe = mpl3115_probe, |
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.remove = mpl3115_remove, |
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.id_table = mpl3115_id, |
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}; |
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module_i2c_driver(mpl3115_driver); |
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MODULE_AUTHOR("Peter Meerwald <[email protected]>"); |
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MODULE_DESCRIPTION("Freescale MPL3115 pressure/temperature driver"); |
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MODULE_LICENSE("GPL");
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