diff options
Diffstat (limited to 'drivers/iio/pressure/mpl115_spi.c')
-rw-r--r-- | drivers/iio/pressure/mpl115_spi.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/iio/pressure/mpl115_spi.c b/drivers/iio/pressure/mpl115_spi.c new file mode 100644 index 0000000000..58d218fd90 --- /dev/null +++ b/drivers/iio/pressure/mpl115_spi.c @@ -0,0 +1,105 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Freescale MPL115A1 pressure/temperature sensor + * + * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com> + * + * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf + */ + +#include <linux/module.h> +#include <linux/spi/spi.h> + +#include "mpl115.h" + +#define MPL115_SPI_WRITE(address) ((address) << 1) +#define MPL115_SPI_READ(address) (0x80 | (address) << 1) + +struct mpl115_spi_buf { + u8 tx[4]; + u8 rx[4]; +}; + +static int mpl115_spi_init(struct device *dev) +{ + struct spi_device *spi = to_spi_device(dev); + struct mpl115_spi_buf *buf; + + buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL); + if (!buf) + return -ENOMEM; + + spi_set_drvdata(spi, buf); + + return 0; +} + +static int mpl115_spi_read(struct device *dev, u8 address) +{ + struct spi_device *spi = to_spi_device(dev); + struct mpl115_spi_buf *buf = spi_get_drvdata(spi); + struct spi_transfer xfer = { + .tx_buf = buf->tx, + .rx_buf = buf->rx, + .len = 4, + }; + int ret; + + buf->tx[0] = MPL115_SPI_READ(address); + buf->tx[2] = MPL115_SPI_READ(address + 1); + + ret = spi_sync_transfer(spi, &xfer, 1); + if (ret) + return ret; + + return (buf->rx[1] << 8) | buf->rx[3]; +} + +static int mpl115_spi_write(struct device *dev, u8 address, u8 value) +{ + struct spi_device *spi = to_spi_device(dev); + struct mpl115_spi_buf *buf = spi_get_drvdata(spi); + struct spi_transfer xfer = { + .tx_buf = buf->tx, + .len = 2, + }; + + buf->tx[0] = MPL115_SPI_WRITE(address); + buf->tx[1] = value; + + return spi_sync_transfer(spi, &xfer, 1); +} + +static const struct mpl115_ops mpl115_spi_ops = { + .init = mpl115_spi_init, + .read = mpl115_spi_read, + .write = mpl115_spi_write, +}; + +static int mpl115_spi_probe(struct spi_device *spi) +{ + const struct spi_device_id *id = spi_get_device_id(spi); + + return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops); +} + +static const struct spi_device_id mpl115_spi_ids[] = { + { "mpl115", 0 }, + {} +}; +MODULE_DEVICE_TABLE(spi, mpl115_spi_ids); + +static struct spi_driver mpl115_spi_driver = { + .driver = { + .name = "mpl115", + .pm = pm_ptr(&mpl115_dev_pm_ops), + }, + .probe = mpl115_spi_probe, + .id_table = mpl115_spi_ids, +}; +module_spi_driver(mpl115_spi_driver); + +MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>"); +MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(IIO_MPL115); |