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 **/
33 struct 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
41 static struct iio_dev *adis16060_iio_dev;
42
adis16060_spi_write(struct iio_dev * indio_dev,u8 val)43 static 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
adis16060_spi_read(struct iio_dev * indio_dev,u16 * val)56 static 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
adis16060_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)79 static 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
113 static const struct iio_info adis16060_info = {
114 .read_raw = &adis16060_read_raw,
115 .driver_module = THIS_MODULE,
116 };
117
118 static 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
adis16060_r_probe(struct spi_device * spi)147 static 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
adis16060_w_probe(struct spi_device * spi)178 static 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
193 error_ret:
194 return ret;
195 }
196
adis16060_w_remove(struct spi_device * spi)197 static int adis16060_w_remove(struct spi_device *spi)
198 {
199 return 0;
200 }
201
202 static struct spi_driver adis16060_r_driver = {
203 .driver = {
204 .name = "adis16060_r",
205 .owner = THIS_MODULE,
206 },
207 .probe = adis16060_r_probe,
208 };
209
210 static 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
adis16060_init(void)219 static __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 }
235 module_init(adis16060_init);
236
adis16060_exit(void)237 static __exit void adis16060_exit(void)
238 {
239 spi_unregister_driver(&adis16060_w_driver);
240 spi_unregister_driver(&adis16060_r_driver);
241 }
242 module_exit(adis16060_exit);
243
244 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
245 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
246 MODULE_LICENSE("GPL v2");
247