1/*
2 * ADIS16130 Digital Output, High Precision Angular Rate Sensor driver
3 *
4 * Copyright 2010 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#include <linux/mutex.h>
10#include <linux/kernel.h>
11#include <linux/spi/spi.h>
12#include <linux/module.h>
13
14#include <linux/iio/iio.h>
15
16#define ADIS16130_CON         0x0
17#define ADIS16130_CON_RD      (1 << 6)
18#define ADIS16130_IOP         0x1
19
20/* 1 = data-ready signal low when unread data on all channels; */
21#define ADIS16130_IOP_ALL_RDY (1 << 3)
22#define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
23#define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
24#define ADIS16130_TEMPDATA    0xA /* Temperature output */
25#define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
26#define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
27#define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
28#define ADIS16130_TEMPCS_EN   (1 << 3)
29#define ADIS16130_RATECONV    0x30
30#define ADIS16130_TEMPCONV    0x32
31#define ADIS16130_MODE        0x38
32#define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
33
34/**
35 * struct adis16130_state - device instance specific data
36 * @us:			actual spi_device to write data
37 * @buf_lock:		mutex to protect tx and rx
38 * @buf:		unified tx/rx buffer
39 **/
40struct adis16130_state {
41	struct spi_device		*us;
42	struct mutex			buf_lock;
43	u8				buf[4] ____cacheline_aligned;
44};
45
46static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
47{
48	int ret;
49	struct adis16130_state *st = iio_priv(indio_dev);
50	struct spi_transfer xfer = {
51		.tx_buf = st->buf,
52		.rx_buf = st->buf,
53		.len = 4,
54	};
55
56	mutex_lock(&st->buf_lock);
57
58	st->buf[0] = ADIS16130_CON_RD | reg_addr;
59	st->buf[1] = st->buf[2] = st->buf[3] = 0;
60
61	ret = spi_sync_transfer(st->us, &xfer, 1);
62	if (ret == 0)
63		*val = (st->buf[1] << 16) | (st->buf[2] << 8) | st->buf[3];
64	mutex_unlock(&st->buf_lock);
65
66	return ret;
67}
68
69static int adis16130_read_raw(struct iio_dev *indio_dev,
70			      struct iio_chan_spec const *chan,
71			      int *val, int *val2,
72			      long mask)
73{
74	int ret;
75	u32 temp;
76
77	switch (mask) {
78	case IIO_CHAN_INFO_RAW:
79		/* Take the iio_dev status lock */
80		mutex_lock(&indio_dev->mlock);
81		ret = adis16130_spi_read(indio_dev, chan->address, &temp);
82		mutex_unlock(&indio_dev->mlock);
83		if (ret)
84			return ret;
85		*val = temp;
86		return IIO_VAL_INT;
87	case IIO_CHAN_INFO_SCALE:
88		switch (chan->type) {
89		case IIO_ANGL_VEL:
90			/* 0 degree = 838860, 250 degree = 14260608 */
91			*val = 250;
92			*val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
93			return IIO_VAL_FRACTIONAL;
94		case IIO_TEMP:
95			/* 0C = 8036283, 105C = 9516048 */
96			*val = 105000;
97			*val2 = 9516048 - 8036283;
98			return IIO_VAL_FRACTIONAL;
99		default:
100			return -EINVAL;
101		}
102	case IIO_CHAN_INFO_OFFSET:
103		switch (chan->type) {
104		case IIO_ANGL_VEL:
105			*val = -8388608;
106			return IIO_VAL_INT;
107		case IIO_TEMP:
108			*val = -8036283;
109			return IIO_VAL_INT;
110		default:
111			return -EINVAL;
112		}
113	}
114
115	return -EINVAL;
116}
117
118static const struct iio_chan_spec adis16130_channels[] = {
119	{
120		.type = IIO_ANGL_VEL,
121		.modified = 1,
122		.channel2 = IIO_MOD_Z,
123		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
124			BIT(IIO_CHAN_INFO_SCALE) |
125			BIT(IIO_CHAN_INFO_OFFSET),
126		.address = ADIS16130_RATEDATA,
127	}, {
128		.type = IIO_TEMP,
129		.indexed = 1,
130		.channel = 0,
131		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
132			BIT(IIO_CHAN_INFO_SCALE) |
133			BIT(IIO_CHAN_INFO_OFFSET),
134		.address = ADIS16130_TEMPDATA,
135	}
136};
137
138static const struct iio_info adis16130_info = {
139	.read_raw = &adis16130_read_raw,
140	.driver_module = THIS_MODULE,
141};
142
143static int adis16130_probe(struct spi_device *spi)
144{
145	struct adis16130_state *st;
146	struct iio_dev *indio_dev;
147
148	/* setup the industrialio driver allocated elements */
149	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
150	if (!indio_dev)
151		return -ENOMEM;
152	st = iio_priv(indio_dev);
153	/* this is only used for removal purposes */
154	spi_set_drvdata(spi, indio_dev);
155	st->us = spi;
156	mutex_init(&st->buf_lock);
157	indio_dev->name = spi->dev.driver->name;
158	indio_dev->channels = adis16130_channels;
159	indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
160	indio_dev->dev.parent = &spi->dev;
161	indio_dev->info = &adis16130_info;
162	indio_dev->modes = INDIO_DIRECT_MODE;
163
164	return devm_iio_device_register(&spi->dev, indio_dev);
165}
166
167static struct spi_driver adis16130_driver = {
168	.driver = {
169		.name = "adis16130",
170		.owner = THIS_MODULE,
171	},
172	.probe = adis16130_probe,
173};
174module_spi_driver(adis16130_driver);
175
176MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
177MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
178MODULE_LICENSE("GPL v2");
179MODULE_ALIAS("spi:adis16130");
180