xref: /openbmc/linux/drivers/iio/gyro/adis16130.c (revision a44e4f3a)
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  **/
39 struct adis16130_state {
40 	struct spi_device		*us;
41 	struct mutex			buf_lock;
42 	u8				buf[4] ____cacheline_aligned;
43 };
44 
45 static 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 
68 static 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 		mutex_lock(&indio_dev->mlock);
80 		ret = adis16130_spi_read(indio_dev, chan->address, &temp);
81 		mutex_unlock(&indio_dev->mlock);
82 		if (ret)
83 			return ret;
84 		*val = temp;
85 		return IIO_VAL_INT;
86 	case IIO_CHAN_INFO_SCALE:
87 		switch (chan->type) {
88 		case IIO_ANGL_VEL:
89 			/* 0 degree = 838860, 250 degree = 14260608 */
90 			*val = 250;
91 			*val2 = 336440817; /* RAD_TO_DEGREE(14260608 - 8388608) */
92 			return IIO_VAL_FRACTIONAL;
93 		case IIO_TEMP:
94 			/* 0C = 8036283, 105C = 9516048 */
95 			*val = 105000;
96 			*val2 = 9516048 - 8036283;
97 			return IIO_VAL_FRACTIONAL;
98 		default:
99 			return -EINVAL;
100 		}
101 	case IIO_CHAN_INFO_OFFSET:
102 		switch (chan->type) {
103 		case IIO_ANGL_VEL:
104 			*val = -8388608;
105 			return IIO_VAL_INT;
106 		case IIO_TEMP:
107 			*val = -8036283;
108 			return IIO_VAL_INT;
109 		default:
110 			return -EINVAL;
111 		}
112 	}
113 
114 	return -EINVAL;
115 }
116 
117 static const struct iio_chan_spec adis16130_channels[] = {
118 	{
119 		.type = IIO_ANGL_VEL,
120 		.modified = 1,
121 		.channel2 = IIO_MOD_Z,
122 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
123 			BIT(IIO_CHAN_INFO_SCALE) |
124 			BIT(IIO_CHAN_INFO_OFFSET),
125 		.address = ADIS16130_RATEDATA,
126 	}, {
127 		.type = IIO_TEMP,
128 		.indexed = 1,
129 		.channel = 0,
130 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
131 			BIT(IIO_CHAN_INFO_SCALE) |
132 			BIT(IIO_CHAN_INFO_OFFSET),
133 		.address = ADIS16130_TEMPDATA,
134 	}
135 };
136 
137 static const struct iio_info adis16130_info = {
138 	.read_raw = &adis16130_read_raw,
139 };
140 
141 static int adis16130_probe(struct spi_device *spi)
142 {
143 	struct adis16130_state *st;
144 	struct iio_dev *indio_dev;
145 
146 	/* setup the industrialio driver allocated elements */
147 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
148 	if (!indio_dev)
149 		return -ENOMEM;
150 	st = iio_priv(indio_dev);
151 	/* this is only used for removal purposes */
152 	spi_set_drvdata(spi, indio_dev);
153 	st->us = spi;
154 	mutex_init(&st->buf_lock);
155 	indio_dev->name = spi->dev.driver->name;
156 	indio_dev->channels = adis16130_channels;
157 	indio_dev->num_channels = ARRAY_SIZE(adis16130_channels);
158 	indio_dev->dev.parent = &spi->dev;
159 	indio_dev->info = &adis16130_info;
160 	indio_dev->modes = INDIO_DIRECT_MODE;
161 
162 	return devm_iio_device_register(&spi->dev, indio_dev);
163 }
164 
165 static struct spi_driver adis16130_driver = {
166 	.driver = {
167 		.name = "adis16130",
168 	},
169 	.probe = adis16130_probe,
170 };
171 module_spi_driver(adis16130_driver);
172 
173 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
174 MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
175 MODULE_LICENSE("GPL v2");
176 MODULE_ALIAS("spi:adis16130");
177