1/*
2 * ADIS16080/100 Yaw Rate Gyroscope with SPI driver
3 *
4 * Copyright 2010 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8#include <linux/delay.h>
9#include <linux/mutex.h>
10#include <linux/device.h>
11#include <linux/kernel.h>
12#include <linux/spi/spi.h>
13#include <linux/slab.h>
14#include <linux/sysfs.h>
15#include <linux/module.h>
16
17#include <linux/iio/iio.h>
18#include <linux/iio/sysfs.h>
19
20#define ADIS16080_DIN_GYRO   (0 << 10) /* Gyroscope output */
21#define ADIS16080_DIN_TEMP   (1 << 10) /* Temperature output */
22#define ADIS16080_DIN_AIN1   (2 << 10)
23#define ADIS16080_DIN_AIN2   (3 << 10)
24
25/*
26 * 1: Write contents on DIN to control register.
27 * 0: No changes to control register.
28 */
29
30#define ADIS16080_DIN_WRITE  (1 << 15)
31
32struct adis16080_chip_info {
33	int scale_val;
34	int scale_val2;
35};
36
37/**
38 * struct adis16080_state - device instance specific data
39 * @us:			actual spi_device to write data
40 * @info:		chip specific parameters
41 * @buf:		transmit or receive buffer
42 **/
43struct adis16080_state {
44	struct spi_device		*us;
45	const struct adis16080_chip_info *info;
46
47	__be16 buf ____cacheline_aligned;
48};
49
50static int adis16080_read_sample(struct iio_dev *indio_dev,
51		u16 addr, int *val)
52{
53	struct adis16080_state *st = iio_priv(indio_dev);
54	int ret;
55	struct spi_transfer	t[] = {
56		{
57			.tx_buf		= &st->buf,
58			.len		= 2,
59			.cs_change	= 1,
60		}, {
61			.rx_buf		= &st->buf,
62			.len		= 2,
63		},
64	};
65
66	st->buf = cpu_to_be16(addr | ADIS16080_DIN_WRITE);
67
68	ret = spi_sync_transfer(st->us, t, ARRAY_SIZE(t));
69	if (ret == 0)
70		*val = sign_extend32(be16_to_cpu(st->buf), 11);
71
72	return ret;
73}
74
75static int adis16080_read_raw(struct iio_dev *indio_dev,
76			     struct iio_chan_spec const *chan,
77			     int *val,
78			     int *val2,
79			     long mask)
80{
81	struct adis16080_state *st = iio_priv(indio_dev);
82	int ret;
83
84	switch (mask) {
85	case IIO_CHAN_INFO_RAW:
86		mutex_lock(&indio_dev->mlock);
87		ret = adis16080_read_sample(indio_dev, chan->address, val);
88		mutex_unlock(&indio_dev->mlock);
89		return ret ? ret : IIO_VAL_INT;
90	case IIO_CHAN_INFO_SCALE:
91		switch (chan->type) {
92		case IIO_ANGL_VEL:
93			*val = st->info->scale_val;
94			*val2 = st->info->scale_val2;
95			return IIO_VAL_FRACTIONAL;
96		case IIO_VOLTAGE:
97			/* VREF = 5V, 12 bits */
98			*val = 5000;
99			*val2 = 12;
100			return IIO_VAL_FRACTIONAL_LOG2;
101		case IIO_TEMP:
102			/* 85 C = 585, 25 C = 0 */
103			*val = 85000 - 25000;
104			*val2 = 585;
105			return IIO_VAL_FRACTIONAL;
106		default:
107			return -EINVAL;
108		}
109	case IIO_CHAN_INFO_OFFSET:
110		switch (chan->type) {
111		case IIO_VOLTAGE:
112			/* 2.5 V = 0 */
113			*val = 2048;
114			return IIO_VAL_INT;
115		case IIO_TEMP:
116			/* 85 C = 585, 25 C = 0 */
117			*val = DIV_ROUND_CLOSEST(25 * 585, 85 - 25);
118			return IIO_VAL_INT;
119		default:
120			return -EINVAL;
121		}
122	default:
123		break;
124	}
125
126	return -EINVAL;
127}
128
129static const struct iio_chan_spec adis16080_channels[] = {
130	{
131		.type = IIO_ANGL_VEL,
132		.modified = 1,
133		.channel2 = IIO_MOD_Z,
134		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
135			BIT(IIO_CHAN_INFO_SCALE),
136		.address = ADIS16080_DIN_GYRO,
137	}, {
138		.type = IIO_VOLTAGE,
139		.indexed = 1,
140		.channel = 0,
141		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
142			BIT(IIO_CHAN_INFO_SCALE) |
143			BIT(IIO_CHAN_INFO_OFFSET),
144		.address = ADIS16080_DIN_AIN1,
145	}, {
146		.type = IIO_VOLTAGE,
147		.indexed = 1,
148		.channel = 1,
149		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
150			BIT(IIO_CHAN_INFO_SCALE) |
151			BIT(IIO_CHAN_INFO_OFFSET),
152		.address = ADIS16080_DIN_AIN2,
153	}, {
154		.type = IIO_TEMP,
155		.indexed = 1,
156		.channel = 0,
157		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
158			BIT(IIO_CHAN_INFO_SCALE) |
159			BIT(IIO_CHAN_INFO_OFFSET),
160		.address = ADIS16080_DIN_TEMP,
161	}
162};
163
164static const struct iio_info adis16080_info = {
165	.read_raw = &adis16080_read_raw,
166	.driver_module = THIS_MODULE,
167};
168
169enum {
170	ID_ADIS16080,
171	ID_ADIS16100,
172};
173
174static const struct adis16080_chip_info adis16080_chip_info[] = {
175	[ID_ADIS16080] = {
176		/* 80 degree = 819, 819 rad = 46925 degree */
177		.scale_val = 80,
178		.scale_val2 = 46925,
179	},
180	[ID_ADIS16100] = {
181		/* 300 degree = 1230, 1230 rad = 70474 degree */
182		.scale_val = 300,
183		.scale_val2 = 70474,
184	},
185};
186
187static int adis16080_probe(struct spi_device *spi)
188{
189	const struct spi_device_id *id = spi_get_device_id(spi);
190	struct adis16080_state *st;
191	struct iio_dev *indio_dev;
192
193	/* setup the industrialio driver allocated elements */
194	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
195	if (!indio_dev)
196		return -ENOMEM;
197	st = iio_priv(indio_dev);
198	/* this is only used for removal purposes */
199	spi_set_drvdata(spi, indio_dev);
200
201	/* Allocate the comms buffers */
202	st->us = spi;
203	st->info = &adis16080_chip_info[id->driver_data];
204
205	indio_dev->name = spi->dev.driver->name;
206	indio_dev->channels = adis16080_channels;
207	indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
208	indio_dev->dev.parent = &spi->dev;
209	indio_dev->info = &adis16080_info;
210	indio_dev->modes = INDIO_DIRECT_MODE;
211
212	return iio_device_register(indio_dev);
213}
214
215static int adis16080_remove(struct spi_device *spi)
216{
217	iio_device_unregister(spi_get_drvdata(spi));
218	return 0;
219}
220
221static const struct spi_device_id adis16080_ids[] = {
222	{ "adis16080", ID_ADIS16080 },
223	{ "adis16100", ID_ADIS16100 },
224	{},
225};
226MODULE_DEVICE_TABLE(spi, adis16080_ids);
227
228static struct spi_driver adis16080_driver = {
229	.driver = {
230		.name = "adis16080",
231		.owner = THIS_MODULE,
232	},
233	.probe = adis16080_probe,
234	.remove = adis16080_remove,
235	.id_table = adis16080_ids,
236};
237module_spi_driver(adis16080_driver);
238
239MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
240MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
241MODULE_LICENSE("GPL v2");
242