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103 lines
2.2 KiB
103 lines
2.2 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Freescale MPL115A1 pressure/temperature sensor |
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* |
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* Copyright (c) 2016 Akinobu Mita <[email protected]> |
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* |
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* Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf |
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*/ |
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#include <linux/module.h> |
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#include <linux/spi/spi.h> |
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#include "mpl115.h" |
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#define MPL115_SPI_WRITE(address) ((address) << 1) |
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#define MPL115_SPI_READ(address) (0x80 | (address) << 1) |
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struct mpl115_spi_buf { |
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u8 tx[4]; |
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u8 rx[4]; |
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}; |
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static int mpl115_spi_init(struct device *dev) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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struct mpl115_spi_buf *buf; |
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buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL); |
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if (!buf) |
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return -ENOMEM; |
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spi_set_drvdata(spi, buf); |
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return 0; |
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} |
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static int mpl115_spi_read(struct device *dev, u8 address) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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struct mpl115_spi_buf *buf = spi_get_drvdata(spi); |
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struct spi_transfer xfer = { |
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.tx_buf = buf->tx, |
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.rx_buf = buf->rx, |
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.len = 4, |
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}; |
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int ret; |
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buf->tx[0] = MPL115_SPI_READ(address); |
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buf->tx[2] = MPL115_SPI_READ(address + 1); |
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ret = spi_sync_transfer(spi, &xfer, 1); |
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if (ret) |
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return ret; |
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return (buf->rx[1] << 8) | buf->rx[3]; |
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} |
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static int mpl115_spi_write(struct device *dev, u8 address, u8 value) |
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{ |
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struct spi_device *spi = to_spi_device(dev); |
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struct mpl115_spi_buf *buf = spi_get_drvdata(spi); |
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struct spi_transfer xfer = { |
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.tx_buf = buf->tx, |
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.len = 2, |
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}; |
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buf->tx[0] = MPL115_SPI_WRITE(address); |
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buf->tx[1] = value; |
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return spi_sync_transfer(spi, &xfer, 1); |
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} |
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static const struct mpl115_ops mpl115_spi_ops = { |
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.init = mpl115_spi_init, |
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.read = mpl115_spi_read, |
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.write = mpl115_spi_write, |
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}; |
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static int mpl115_spi_probe(struct spi_device *spi) |
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{ |
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const struct spi_device_id *id = spi_get_device_id(spi); |
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return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops); |
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} |
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static const struct spi_device_id mpl115_spi_ids[] = { |
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{ "mpl115", 0 }, |
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{} |
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}; |
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MODULE_DEVICE_TABLE(spi, mpl115_spi_ids); |
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static struct spi_driver mpl115_spi_driver = { |
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.driver = { |
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.name = "mpl115", |
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}, |
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.probe = mpl115_spi_probe, |
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.id_table = mpl115_spi_ids, |
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}; |
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module_spi_driver(mpl115_spi_driver); |
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MODULE_AUTHOR("Akinobu Mita <[email protected]>"); |
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MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver"); |
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MODULE_LICENSE("GPL");
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