1/*
2 * ADIS16060 Wide Bandwidth Yaw Rate Gyroscope with SPI driver
3 *
4 * Copyright 2010 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2 or later.
7 */
8
9#include <linux/module.h>
10#include <linux/delay.h>
11#include <linux/mutex.h>
12#include <linux/device.h>
13#include <linux/kernel.h>
14#include <linux/spi/spi.h>
15#include <linux/slab.h>
16#include <linux/sysfs.h>
17
18#include <linux/iio/iio.h>
19#include <linux/iio/sysfs.h>
20
21#define ADIS16060_GYRO		0x20 /* Measure Angular Rate (Gyro) */
22#define ADIS16060_TEMP_OUT	0x10 /* Measure Temperature */
23#define ADIS16060_AIN2		0x80 /* Measure AIN2 */
24#define ADIS16060_AIN1		0x40 /* Measure AIN1 */
25
26/**
27 * struct adis16060_state - device instance specific data
28 * @us_w:		actual spi_device to write config
29 * @us_r:		actual spi_device to read back data
30 * @buf:		transmit or receive buffer
31 * @buf_lock:		mutex to protect tx and rx
32 **/
33struct adis16060_state {
34	struct spi_device		*us_w;
35	struct spi_device		*us_r;
36	struct mutex			buf_lock;
37
38	u8 buf[3] ____cacheline_aligned;
39};
40
41static struct iio_dev *adis16060_iio_dev;
42
43static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
44{
45	int ret;
46	struct adis16060_state *st = iio_priv(indio_dev);
47
48	mutex_lock(&st->buf_lock);
49	st->buf[2] = val; /* The last 8 bits clocked in are latched */
50	ret = spi_write(st->us_w, st->buf, 3);
51	mutex_unlock(&st->buf_lock);
52
53	return ret;
54}
55
56static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
57{
58	int ret;
59	struct adis16060_state *st = iio_priv(indio_dev);
60
61	mutex_lock(&st->buf_lock);
62
63	ret = spi_read(st->us_r, st->buf, 3);
64
65	/* The internal successive approximation ADC begins the
66	 * conversion process on the falling edge of MSEL1 and
67	 * starts to place data MSB first on the DOUT line at
68	 * the 6th falling edge of SCLK
69	 */
70	if (ret == 0)
71		*val = ((st->buf[0] & 0x3) << 12) |
72			(st->buf[1] << 4) |
73			((st->buf[2] >> 4) & 0xF);
74	mutex_unlock(&st->buf_lock);
75
76	return ret;
77}
78
79static int adis16060_read_raw(struct iio_dev *indio_dev,
80			      struct iio_chan_spec const *chan,
81			      int *val, int *val2,
82			      long mask)
83{
84	u16 tval = 0;
85	int ret;
86
87	switch (mask) {
88	case IIO_CHAN_INFO_RAW:
89		/* Take the iio_dev status lock */
90		mutex_lock(&indio_dev->mlock);
91		ret = adis16060_spi_write(indio_dev, chan->address);
92		if (ret < 0) {
93			mutex_unlock(&indio_dev->mlock);
94			return ret;
95		}
96		ret = adis16060_spi_read(indio_dev, &tval);
97		mutex_unlock(&indio_dev->mlock);
98		*val = tval;
99		return IIO_VAL_INT;
100	case IIO_CHAN_INFO_OFFSET:
101		*val = -7;
102		*val2 = 461117;
103		return IIO_VAL_INT_PLUS_MICRO;
104	case IIO_CHAN_INFO_SCALE:
105		*val = 0;
106		*val2 = 34000;
107		return IIO_VAL_INT_PLUS_MICRO;
108	}
109
110	return -EINVAL;
111}
112
113static const struct iio_info adis16060_info = {
114	.read_raw = &adis16060_read_raw,
115	.driver_module = THIS_MODULE,
116};
117
118static const struct iio_chan_spec adis16060_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		.address = ADIS16060_GYRO,
125	}, {
126		.type = IIO_VOLTAGE,
127		.indexed = 1,
128		.channel = 0,
129		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
130		.address = ADIS16060_AIN1,
131	}, {
132		.type = IIO_VOLTAGE,
133		.indexed = 1,
134		.channel = 1,
135		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
136		.address = ADIS16060_AIN2,
137	}, {
138		.type = IIO_TEMP,
139		.indexed = 1,
140		.channel = 0,
141		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
142		BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE),
143		.address = ADIS16060_TEMP_OUT,
144	}
145};
146
147static int adis16060_r_probe(struct spi_device *spi)
148{
149	int ret;
150	struct adis16060_state *st;
151	struct iio_dev *indio_dev;
152
153	/* setup the industrialio driver allocated elements */
154	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
155	if (!indio_dev)
156		return -ENOMEM;
157	/* this is only used for removal purposes */
158	spi_set_drvdata(spi, indio_dev);
159	st = iio_priv(indio_dev);
160	st->us_r = spi;
161	mutex_init(&st->buf_lock);
162
163	indio_dev->name = spi->dev.driver->name;
164	indio_dev->dev.parent = &spi->dev;
165	indio_dev->info = &adis16060_info;
166	indio_dev->modes = INDIO_DIRECT_MODE;
167	indio_dev->channels = adis16060_channels;
168	indio_dev->num_channels = ARRAY_SIZE(adis16060_channels);
169
170	ret = devm_iio_device_register(&spi->dev, indio_dev);
171	if (ret)
172		return ret;
173
174	adis16060_iio_dev = indio_dev;
175	return 0;
176}
177
178static int adis16060_w_probe(struct spi_device *spi)
179{
180	int ret;
181	struct iio_dev *indio_dev = adis16060_iio_dev;
182	struct adis16060_state *st;
183
184	if (!indio_dev) {
185		ret =  -ENODEV;
186		goto error_ret;
187	}
188	st = iio_priv(indio_dev);
189	spi_set_drvdata(spi, indio_dev);
190	st->us_w = spi;
191	return 0;
192
193error_ret:
194	return ret;
195}
196
197static int adis16060_w_remove(struct spi_device *spi)
198{
199	return 0;
200}
201
202static struct spi_driver adis16060_r_driver = {
203	.driver = {
204		.name = "adis16060_r",
205		.owner = THIS_MODULE,
206	},
207	.probe = adis16060_r_probe,
208};
209
210static struct spi_driver adis16060_w_driver = {
211	.driver = {
212		.name = "adis16060_w",
213		.owner = THIS_MODULE,
214	},
215	.probe = adis16060_w_probe,
216	.remove = adis16060_w_remove,
217};
218
219static __init int adis16060_init(void)
220{
221	int ret;
222
223	ret = spi_register_driver(&adis16060_r_driver);
224	if (ret < 0)
225		return ret;
226
227	ret = spi_register_driver(&adis16060_w_driver);
228	if (ret < 0) {
229		spi_unregister_driver(&adis16060_r_driver);
230		return ret;
231	}
232
233	return 0;
234}
235module_init(adis16060_init);
236
237static __exit void adis16060_exit(void)
238{
239	spi_unregister_driver(&adis16060_w_driver);
240	spi_unregister_driver(&adis16060_r_driver);
241}
242module_exit(adis16060_exit);
243
244MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
245MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
246MODULE_LICENSE("GPL v2");
247