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 "../iio.h"
18#include "../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
32/**
33 * struct adis16080_state - device instance specific data
34 * @us:			actual spi_device to write data
35 * @buf:		transmit or receive buffer
36 * @buf_lock:		mutex to protect tx and rx
37 **/
38struct adis16080_state {
39	struct spi_device		*us;
40	struct mutex			buf_lock;
41
42	u8 buf[2] ____cacheline_aligned;
43};
44
45static int adis16080_spi_write(struct iio_dev *indio_dev,
46		u16 val)
47{
48	int ret;
49	struct adis16080_state *st = iio_priv(indio_dev);
50
51	mutex_lock(&st->buf_lock);
52	st->buf[0] = val >> 8;
53	st->buf[1] = val;
54
55	ret = spi_write(st->us, st->buf, 2);
56	mutex_unlock(&st->buf_lock);
57
58	return ret;
59}
60
61static int adis16080_spi_read(struct iio_dev *indio_dev,
62			      u16 *val)
63{
64	int ret;
65	struct adis16080_state *st = iio_priv(indio_dev);
66
67	mutex_lock(&st->buf_lock);
68
69	ret = spi_read(st->us, st->buf, 2);
70
71	if (ret == 0)
72		*val = ((st->buf[0] & 0xF) << 8) | st->buf[1];
73	mutex_unlock(&st->buf_lock);
74
75	return ret;
76}
77
78static int adis16080_read_raw(struct iio_dev *indio_dev,
79			     struct iio_chan_spec const *chan,
80			     int *val,
81			     int *val2,
82			     long mask)
83{
84	int ret = -EINVAL;
85	u16 ut;
86	/* Take the iio_dev status lock */
87
88	mutex_lock(&indio_dev->mlock);
89	switch (mask) {
90	case 0:
91		ret = adis16080_spi_write(indio_dev,
92					  chan->address |
93					  ADIS16080_DIN_WRITE);
94		if (ret < 0)
95			break;
96		ret = adis16080_spi_read(indio_dev, &ut);
97		if (ret < 0)
98			break;
99		*val = ut;
100		ret = IIO_VAL_INT;
101		break;
102	}
103	mutex_unlock(&indio_dev->mlock);
104
105	return ret;
106}
107
108static const struct iio_chan_spec adis16080_channels[] = {
109	{
110		.type = IIO_ANGL_VEL,
111		.modified = 1,
112		.channel2 = IIO_MOD_Z,
113		.address = ADIS16080_DIN_GYRO,
114	}, {
115		.type = IIO_VOLTAGE,
116		.indexed = 1,
117		.channel = 0,
118		.address = ADIS16080_DIN_AIN1,
119	}, {
120		.type = IIO_VOLTAGE,
121		.indexed = 1,
122		.channel = 1,
123		.address = ADIS16080_DIN_AIN2,
124	}, {
125		.type = IIO_TEMP,
126		.indexed = 1,
127		.channel = 0,
128		.address = ADIS16080_DIN_TEMP,
129	}
130};
131
132static const struct iio_info adis16080_info = {
133	.read_raw = &adis16080_read_raw,
134	.driver_module = THIS_MODULE,
135};
136
137static int __devinit adis16080_probe(struct spi_device *spi)
138{
139	int ret;
140	struct adis16080_state *st;
141	struct iio_dev *indio_dev;
142
143	/* setup the industrialio driver allocated elements */
144	indio_dev = iio_allocate_device(sizeof(*st));
145	if (indio_dev == NULL) {
146		ret = -ENOMEM;
147		goto error_ret;
148	}
149	st = iio_priv(indio_dev);
150	/* this is only used for removal purposes */
151	spi_set_drvdata(spi, indio_dev);
152
153	/* Allocate the comms buffers */
154	st->us = spi;
155	mutex_init(&st->buf_lock);
156
157	indio_dev->name = spi->dev.driver->name;
158	indio_dev->channels = adis16080_channels;
159	indio_dev->num_channels = ARRAY_SIZE(adis16080_channels);
160	indio_dev->dev.parent = &spi->dev;
161	indio_dev->info = &adis16080_info;
162	indio_dev->modes = INDIO_DIRECT_MODE;
163
164	ret = iio_device_register(indio_dev);
165	if (ret)
166		goto error_free_dev;
167	return 0;
168
169error_free_dev:
170	iio_free_device(indio_dev);
171error_ret:
172	return ret;
173}
174
175/* fixme, confirm ordering in this function */
176static int adis16080_remove(struct spi_device *spi)
177{
178	iio_device_unregister(spi_get_drvdata(spi));
179	iio_free_device(spi_get_drvdata(spi));
180
181	return 0;
182}
183
184static struct spi_driver adis16080_driver = {
185	.driver = {
186		.name = "adis16080",
187		.owner = THIS_MODULE,
188	},
189	.probe = adis16080_probe,
190	.remove = __devexit_p(adis16080_remove),
191};
192module_spi_driver(adis16080_driver);
193
194MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
195MODULE_DESCRIPTION("Analog Devices ADIS16080/100 Yaw Rate Gyroscope Driver");
196MODULE_LICENSE("GPL v2");
197MODULE_ALIAS("spi:adis16080");
198