1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Freescale MPL115A1 pressure/temperature sensor
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Datasheet: http://www.nxp.com/files/sensors/doc/data_sheet/MPL115A1.pdf
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/module.h>
11*4882a593Smuzhiyun #include <linux/spi/spi.h>
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun #include "mpl115.h"
14*4882a593Smuzhiyun
15*4882a593Smuzhiyun #define MPL115_SPI_WRITE(address) ((address) << 1)
16*4882a593Smuzhiyun #define MPL115_SPI_READ(address) (0x80 | (address) << 1)
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun struct mpl115_spi_buf {
19*4882a593Smuzhiyun u8 tx[4];
20*4882a593Smuzhiyun u8 rx[4];
21*4882a593Smuzhiyun };
22*4882a593Smuzhiyun
mpl115_spi_init(struct device * dev)23*4882a593Smuzhiyun static int mpl115_spi_init(struct device *dev)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun struct spi_device *spi = to_spi_device(dev);
26*4882a593Smuzhiyun struct mpl115_spi_buf *buf;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun buf = devm_kzalloc(dev, sizeof(*buf), GFP_KERNEL);
29*4882a593Smuzhiyun if (!buf)
30*4882a593Smuzhiyun return -ENOMEM;
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun spi_set_drvdata(spi, buf);
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun return 0;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
mpl115_spi_read(struct device * dev,u8 address)37*4882a593Smuzhiyun static int mpl115_spi_read(struct device *dev, u8 address)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun struct spi_device *spi = to_spi_device(dev);
40*4882a593Smuzhiyun struct mpl115_spi_buf *buf = spi_get_drvdata(spi);
41*4882a593Smuzhiyun struct spi_transfer xfer = {
42*4882a593Smuzhiyun .tx_buf = buf->tx,
43*4882a593Smuzhiyun .rx_buf = buf->rx,
44*4882a593Smuzhiyun .len = 4,
45*4882a593Smuzhiyun };
46*4882a593Smuzhiyun int ret;
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun buf->tx[0] = MPL115_SPI_READ(address);
49*4882a593Smuzhiyun buf->tx[2] = MPL115_SPI_READ(address + 1);
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun ret = spi_sync_transfer(spi, &xfer, 1);
52*4882a593Smuzhiyun if (ret)
53*4882a593Smuzhiyun return ret;
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun return (buf->rx[1] << 8) | buf->rx[3];
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
mpl115_spi_write(struct device * dev,u8 address,u8 value)58*4882a593Smuzhiyun static int mpl115_spi_write(struct device *dev, u8 address, u8 value)
59*4882a593Smuzhiyun {
60*4882a593Smuzhiyun struct spi_device *spi = to_spi_device(dev);
61*4882a593Smuzhiyun struct mpl115_spi_buf *buf = spi_get_drvdata(spi);
62*4882a593Smuzhiyun struct spi_transfer xfer = {
63*4882a593Smuzhiyun .tx_buf = buf->tx,
64*4882a593Smuzhiyun .len = 2,
65*4882a593Smuzhiyun };
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun buf->tx[0] = MPL115_SPI_WRITE(address);
68*4882a593Smuzhiyun buf->tx[1] = value;
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun return spi_sync_transfer(spi, &xfer, 1);
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun static const struct mpl115_ops mpl115_spi_ops = {
74*4882a593Smuzhiyun .init = mpl115_spi_init,
75*4882a593Smuzhiyun .read = mpl115_spi_read,
76*4882a593Smuzhiyun .write = mpl115_spi_write,
77*4882a593Smuzhiyun };
78*4882a593Smuzhiyun
mpl115_spi_probe(struct spi_device * spi)79*4882a593Smuzhiyun static int mpl115_spi_probe(struct spi_device *spi)
80*4882a593Smuzhiyun {
81*4882a593Smuzhiyun const struct spi_device_id *id = spi_get_device_id(spi);
82*4882a593Smuzhiyun
83*4882a593Smuzhiyun return mpl115_probe(&spi->dev, id->name, &mpl115_spi_ops);
84*4882a593Smuzhiyun }
85*4882a593Smuzhiyun
86*4882a593Smuzhiyun static const struct spi_device_id mpl115_spi_ids[] = {
87*4882a593Smuzhiyun { "mpl115", 0 },
88*4882a593Smuzhiyun {}
89*4882a593Smuzhiyun };
90*4882a593Smuzhiyun MODULE_DEVICE_TABLE(spi, mpl115_spi_ids);
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun static struct spi_driver mpl115_spi_driver = {
93*4882a593Smuzhiyun .driver = {
94*4882a593Smuzhiyun .name = "mpl115",
95*4882a593Smuzhiyun },
96*4882a593Smuzhiyun .probe = mpl115_spi_probe,
97*4882a593Smuzhiyun .id_table = mpl115_spi_ids,
98*4882a593Smuzhiyun };
99*4882a593Smuzhiyun module_spi_driver(mpl115_spi_driver);
100*4882a593Smuzhiyun
101*4882a593Smuzhiyun MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
102*4882a593Smuzhiyun MODULE_DESCRIPTION("Freescale MPL115A1 pressure/temperature driver");
103*4882a593Smuzhiyun MODULE_LICENSE("GPL");
104