projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| c984b9cb AM |
1 | /* |
| 2 | * Freescale MPL115A1 pressure/temperature sensor | |
| 3 | * | |
| 4 | * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com> | |
| 5 | * | |
| 6 | * This file is subject to the terms and conditions of version 2 of | |
| 7 | * the GNU General Public License. See the file COPYING in the main | |
| 8 | * directory of this archive for more details. | |
| 9 | * | |
| 10 | * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf | |
| 11 | */ | |
| 12 | ||
| 13 | #include <linux/module.h> | |
| 14 | #include <linux/spi/spi.h> | |
| 15 | ||
| 16 | #include "mpl115.h" | |
| 17 | ||
| 18 | #define MPL115_SPI_WRITE(address) ((address) << 1) | |
| 19 | #define MPL115_SPI_READ(address) (0x80 | (address) << 1) | |
| 20 | ||
| 21 | struct mpl115_spi_buf { | |
| 22 | u8 tx[4]; | |
| 23 | u8 rx[4]; | |
| 24 | }; | |
| 25 | ||
| 26 | static int mpl115_spi_init(struct device *dev) | |
| 27 | { | |
| 28 | struct spi_device *spi = to_spi_device(dev); | |
| 29 | struct mpl115_spi_buf *buf; | |
| 30 | ||
| 31 | buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL); | |
| 32 | if (!buf) | |
| 33 | return -ENOMEM; | |
| 34 | ||
| 35 | spi_set_drvdata(spi, buf); | |
| 36 | ||
| 37 | return 0; | |
| 38 | } | |
| 39 | ||
| 40 | static int mpl115_spi_read(struct device *dev, u8 address) | |
| 41 | { | |
| 42 | struct spi_device *spi = to_spi_device(dev); | |
| 43 | struct mpl115_spi_buf *buf = spi_get_drvdata(spi); | |
| 44 | struct spi_transfer xfer = { | |
| 45 | .tx_buf = buf->tx, | |
| 46 | .rx_buf = buf->rx, | |
| 47 | .len = 4, | |
| 48 | }; | |
| 49 | int ret; | |
| 50 | ||
| 51 | buf->tx[0] = MPL115_SPI_READ(address); | |
| 52 | buf->tx[2] = MPL115_SPI_READ(address + 1); | |
| 53 | ||
| 54 | ret = spi_sync_transfer(spi, &xfer, 1); | |
| 55 | if (ret) | |
| 56 | return ret; | |
| 57 | ||
| 58 | return (buf->rx[1] << 8) | buf->rx[3]; | |
| 59 | } | |
| 60 | ||
| 61 | static int mpl115_spi_write(struct device *dev, u8 address, u8 value) | |
| 62 | { | |
| 63 | struct spi_device *spi = to_spi_device(dev); | |
| 64 | struct mpl115_spi_buf *buf = spi_get_drvdata(spi); | |
| 65 | struct spi_transfer xfer = { | |
| 66 | .tx_buf = buf->tx, | |
| 67 | .len = 2, | |
| 68 | }; | |
| 69 | ||
| 70 | buf->tx[0] = MPL115_SPI_WRITE(address); | |
| 71 | buf->tx[1] = value; | |
| 72 | ||
| 73 | return spi_sync_transfer(spi, &xfer, 1); | |
| 74 | } | |
| 75 | ||
| 76 | static const struct mpl115_ops mpl115_spi_ops = { | |
| 77 | .init = mpl115_spi_init, | |
| 78 | .read = mpl115_spi_read, | |
| 79 | .write = mpl115_spi_write, | |
| 80 | }; | |
| 81 | ||
| 82 | static int mpl115_spi_probe(struct spi_device *spi) | |
| 83 | { | |
| 84 | const struct spi_device_id *id = spi_get_device_id(spi); | |
| 85 | ||
| 86 | return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops); | |
| 87 | } | |
| 88 | ||
| 89 | static const struct spi_device_id mpl115_spi_ids[] = { | |
| 90 | { "mpl115", 0 }, | |
| 91 | {} | |
| 92 | }; | |
| 93 | MODULE_DEVICE_TABLE(spi, mpl115_spi_ids); | |
| 94 | ||
| 95 | static struct spi_driver mpl115_spi_driver = { | |
| 96 | .driver = { | |
| 97 | .name = "mpl115", | |
| 98 | }, | |
| 99 | .probe = mpl115_spi_probe, | |
| 100 | .id_table = mpl115_spi_ids, | |
| 101 | }; | |
| 102 | module_spi_driver(mpl115_spi_driver); | |
| 103 | ||
| 104 | MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>"); | |
| 105 | MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver"); | |
| 106 | MODULE_LICENSE("GPL"); |