adis16130.c

  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#include <linux/unaligned.h>
 16
 17#define ADIS16130_CON         0x0
 18#define ADIS16130_CON_RD      (1 << 6)
 19#define ADIS16130_IOP         0x1
 20
 21/* 1 = data-ready signal low when unread data on all channels; */
 22#define ADIS16130_IOP_ALL_RDY (1 << 3)
 23#define ADIS16130_IOP_SYNC    (1 << 0) /* 1 = synchronization enabled */
 24#define ADIS16130_RATEDATA    0x8 /* Gyroscope output, rate of rotation */
 25#define ADIS16130_TEMPDATA    0xA /* Temperature output */
 26#define ADIS16130_RATECS      0x28 /* Gyroscope channel setup */
 27#define ADIS16130_RATECS_EN   (1 << 3) /* 1 = channel enable; */
 28#define ADIS16130_TEMPCS      0x2A /* Temperature channel setup */
 29#define ADIS16130_TEMPCS_EN   (1 << 3)
 30#define ADIS16130_RATECONV    0x30
 31#define ADIS16130_TEMPCONV    0x32
 32#define ADIS16130_MODE        0x38
 33#define ADIS16130_MODE_24BIT  (1 << 1) /* 1 = 24-bit resolution; */
 34
 35/**
 36 * struct adis16130_state - device instance specific data
 37 * @us:			actual spi_device to write data
 38 * @buf_lock:		mutex to protect tx and rx
 39 * @buf:		unified tx/rx buffer
 40 **/
 41struct adis16130_state {
 42	struct spi_device		*us;
 43	struct mutex			buf_lock;
 44	u8				buf[4] __aligned(IIO_DMA_MINALIGN);
 45};
 46
 47static int adis16130_spi_read(struct iio_dev *indio_dev, u8 reg_addr, u32 *val)
 48{
 49	int ret;
 50	struct adis16130_state *st = iio_priv(indio_dev);
 51	struct spi_transfer xfer = {
 52		.tx_buf = st->buf,
 53		.rx_buf = st->buf,
 54		.len = 4,
 55	};
 56
 57	mutex_lock(&st->buf_lock);
 58
 59	st->buf[0] = ADIS16130_CON_RD | reg_addr;
 60	st->buf[1] = st->buf[2] = st->buf[3] = 0;
 61
 62	ret = spi_sync_transfer(st->us, &xfer, 1);
 63	if (ret == 0)
 64		*val = get_unaligned_be24(&st->buf[1]);
 65	mutex_unlock(&st->buf_lock);
 66
 67	return ret;
 68}
 69
 70static int adis16130_read_raw(struct iio_dev *indio_dev,
 71			      struct iio_chan_spec const *chan,
 72			      int *val, int *val2,
 73			      long mask)
 74{
 75	int ret;
 76	u32 temp;
 77
 78	switch (mask) {
 79	case IIO_CHAN_INFO_RAW:
 80		/* Take the iio_dev status lock */
 81		ret = adis16130_spi_read(indio_dev, chan->address, &temp);
 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
117static 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
137static const struct iio_info adis16130_info = {
138	.read_raw = &adis16130_read_raw,
139};
140
141static 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->info = &adis16130_info;
159	indio_dev->modes = INDIO_DIRECT_MODE;
160
161	return devm_iio_device_register(&spi->dev, indio_dev);
162}
163
164static struct spi_driver adis16130_driver = {
165	.driver = {
166		.name = "adis16130",
167	},
168	.probe = adis16130_probe,
169};
170module_spi_driver(adis16130_driver);
171
172MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
173MODULE_DESCRIPTION("Analog Devices ADIS16130 High Precision Angular Rate");
174MODULE_LICENSE("GPL v2");
175MODULE_ALIAS("spi:adis16130");