106 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Freescale MPL115A1 pressure/temperature sensor4 *5 * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>6 *7 * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf8 */9 10#include <linux/module.h>11#include <linux/spi/spi.h>12 13#include "mpl115.h"14 15#define MPL115_SPI_WRITE(address) ((address) << 1)16#define MPL115_SPI_READ(address) (0x80 | (address) << 1)17 18struct mpl115_spi_buf {19 u8 tx[4];20 u8 rx[4];21};22 23static int mpl115_spi_init(struct device *dev)24{25 struct spi_device *spi = to_spi_device(dev);26 struct mpl115_spi_buf *buf;27 28 buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL);29 if (!buf)30 return -ENOMEM;31 32 spi_set_drvdata(spi, buf);33 34 return 0;35}36 37static int mpl115_spi_read(struct device *dev, u8 address)38{39 struct spi_device *spi = to_spi_device(dev);40 struct mpl115_spi_buf *buf = spi_get_drvdata(spi);41 struct spi_transfer xfer = {42 .tx_buf = buf->tx,43 .rx_buf = buf->rx,44 .len = 4,45 };46 int ret;47 48 buf->tx[0] = MPL115_SPI_READ(address);49 buf->tx[2] = MPL115_SPI_READ(address + 1);50 51 ret = spi_sync_transfer(spi, &xfer, 1);52 if (ret)53 return ret;54 55 return (buf->rx[1] << 8) | buf->rx[3];56}57 58static int mpl115_spi_write(struct device *dev, u8 address, u8 value)59{60 struct spi_device *spi = to_spi_device(dev);61 struct mpl115_spi_buf *buf = spi_get_drvdata(spi);62 struct spi_transfer xfer = {63 .tx_buf = buf->tx,64 .len = 2,65 };66 67 buf->tx[0] = MPL115_SPI_WRITE(address);68 buf->tx[1] = value;69 70 return spi_sync_transfer(spi, &xfer, 1);71}72 73static const struct mpl115_ops mpl115_spi_ops = {74 .init = mpl115_spi_init,75 .read = mpl115_spi_read,76 .write = mpl115_spi_write,77};78 79static int mpl115_spi_probe(struct spi_device *spi)80{81 const struct spi_device_id *id = spi_get_device_id(spi);82 83 return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops);84}85 86static const struct spi_device_id mpl115_spi_ids[] = {87 { "mpl115", 0 },88 {}89};90MODULE_DEVICE_TABLE(spi, mpl115_spi_ids);91 92static struct spi_driver mpl115_spi_driver = {93 .driver = {94 .name = "mpl115",95 .pm = pm_ptr(&mpl115_dev_pm_ops),96 },97 .probe = mpl115_spi_probe,98 .id_table = mpl115_spi_ids,99};100module_spi_driver(mpl115_spi_driver);101 102MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");103MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver");104MODULE_LICENSE("GPL");105MODULE_IMPORT_NS(IIO_MPL115);106