1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Freescale MPL115A1 pressure/temperature sensor
4 *
5 * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
6 *
7 * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf
8 */
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, size: sizeof(*buf), GFP_KERNEL);
29 if (!buf)
30 return -ENOMEM;
31
32 spi_set_drvdata(spi, data: 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, xfers: &xfer, num_xfers: 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, xfers: &xfer, num_xfers: 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(sdev: spi);
82
83 return mpl115_probe(dev: &spi->dev, name: id->name, ops: &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

source code of linux/drivers/iio/pressure/mpl115_spi.c