tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
4 *
5 * Copyright 2010 Analog Devices Inc.
6 */
7
8#include <linux/mutex.h>
9#include <linux/kernel.h>
10#include <linux/spi/spi.h>
11#include <linux/module.h>
12
13#include <linux/iio/iio.h>
14
15#define ADIS16130_CON 0x0
16#define ADIS16130_CON_RD (1 << 6)
17#define ADIS16130_IOP 0x1
18
19/* 1 = data-ready signal low when unread data on all channels; */
20#define ADIS16130_IOP_ALL_RDY (1 << 3)
21#define ADIS16130_IOP_SYNC (1 << 0) /* 1 = synchronization enabled */
22#define ADIS16130_RATEDATA 0x8 /* Gyroscope output, rate of rotation */
23#define ADIS16130_TEMPDATA 0xA /* Temperature output */
24#define ADIS16130_RATECS 0x28 /* Gyroscope channel setup */
25#define ADIS16130_RATECS_EN (1 << 3) /* 1 = channel enable; */
26#define ADIS16130_TEMPCS 0x2A /* Temperature channel setup */
27#define ADIS16130_TEMPCS_EN (1 << 3)
28#define ADIS16130_RATECONV 0x30
29#define ADIS16130_TEMPCONV 0x32
30#define ADIS16130_MODE 0x38
31#define ADIS16130_MODE_24BIT (1 << 1) /* 1 = 24-bit resolution; */
32
33/**
34 * struct adis16130_state - device instance specific data
35 * @us: actual spi_device to write data
36 * @buf_lock: mutex to protect tx and rx
37 * @buf: unified tx/rx buffer
38 **/
39struct adis16130_state {
40 struct spi_device *us;
41 struct mutex buf_lock;
42 u8 buf[4] ____cacheline_aligned;
43};
44
45static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
46{
47 int ret;
48 struct adis16130_state *st = iio_priv(indio_dev);
49 struct spi_transfer xfer = {
50 .tx_buf = st->buf,
51 .rx_buf = st->buf,
52 .len = 4,
53 };
54
55 mutex_lock(&st->buf_lock);
56
57 st->buf[0] = ADIS16130_CON_RD | reg_addr;
58 st->buf[1] = st->buf[2] = st->buf[3] = 0;
59
60 ret = spi_sync_transfer(st->us, &xfer, 1);
61 if (ret == 0)
62 *val = (st->buf[1] << 16) | (st->buf[2] << 8) | st->buf[3];
63 mutex_unlock(&st->buf_lock);
64
65 return ret;
66}
67
68static int adis16130_read_raw(struct iio_dev *indio_dev,
69 struct iio_chan_spec const *chan,
70 int *val, int *val2,
71 long mask)
72{
73 int ret;
74 u32 temp;
75
76 switch (mask) {
77 case IIO_CHAN_INFO_RAW:
78 /* Take the iio_dev status lock */
79 ret = adis16130_spi_read(indio_dev, chan->address, &temp);
80 if (ret)
81 return ret;
82 *val = temp;
83 return IIO_VAL_INT;
84 case IIO_CHAN_INFO_SCALE:
85 switch (chan->type) {
86 case IIO_ANGL_VEL:
87 /* 0 degree = 838860, 250 degree = 14260608 */
88 *val = 250;
89 *val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
90 return IIO_VAL_FRACTIONAL;
91 case IIO_TEMP:
92 /* 0C = 8036283, 105C = 9516048 */
93 *val = 105000;
94 *val2 = 9516048 - 8036283;
95 return IIO_VAL_FRACTIONAL;
96 default:
97 return -EINVAL;
98 }
99 case IIO_CHAN_INFO_OFFSET:
100 switch (chan->type) {
101 case IIO_ANGL_VEL:
102 *val = -8388608;
103 return IIO_VAL_INT;
104 case IIO_TEMP:
105 *val = -8036283;
106 return IIO_VAL_INT;
107 default:
108 return -EINVAL;
109 }
110 }
111
112 return -EINVAL;
113}
114
115static const struct iio_chan_spec adis16130_channels[] = {
116 {
117 .type = IIO_ANGL_VEL,
118 .modified = 1,
119 .channel2 = IIO_MOD_Z,
120 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
121 BIT(IIO_CHAN_INFO_SCALE) |
122 BIT(IIO_CHAN_INFO_OFFSET),
123 .address = ADIS16130_RATEDATA,
124 }, {
125 .type = IIO_TEMP,
126 .indexed = 1,
127 .channel = 0,
128 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
129 BIT(IIO_CHAN_INFO_SCALE) |
130 BIT(IIO_CHAN_INFO_OFFSET),
131 .address = ADIS16130_TEMPDATA,
132 }
133};
134
135static const struct iio_info adis16130_info = {
136 .read_raw = &adis16130_read_raw,
137};
138
139static int adis16130_probe(struct spi_device *spi)
140{
141 struct adis16130_state *st;
142 struct iio_dev *indio_dev;
143
144 /* setup the industrialio driver allocated elements */
145 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
146 if (!indio_dev)
147 return -ENOMEM;
148 st = iio_priv(indio_dev);
149 /* this is only used for removal purposes */
150 spi_set_drvdata(spi, indio_dev);
151 st->us = spi;
152 mutex_init(&st->buf_lock);
153 indio_dev->name = spi->dev.driver->name;
154 indio_dev->channels = adis16130_channels;
155 indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
156 indio_dev->dev.parent = &spi->dev;
157 indio_dev->info = &adis16130_info;
158 indio_dev->modes = INDIO_DIRECT_MODE;
159
160 return devm_iio_device_register(&spi->dev, indio_dev);
161}
162
163static struct spi_driver adis16130_driver = {
164 .driver = {
165 .name = "adis16130",
166 },
167 .probe = adis16130_probe,
168};
169module_spi_driver(adis16130_driver);
170
171MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
172MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
173MODULE_LICENSE("GPL v2");
174MODULE_ALIAS("spi:adis16130");