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 #include <linux/module.h>
18
19 #include "../iio.h"
20 #include "../sysfs.h"
21
22 #define ADIS16060_GYRO 0x20 /* Measure Angular Rate (Gyro) */
23 #define ADIS16060_TEMP_OUT 0x10 /* Measure Temperature */
24 #define ADIS16060_AIN2 0x80 /* Measure AIN2 */
25 #define ADIS16060_AIN1 0x40 /* Measure AIN1 */
26
27 /**
28 * struct adis16060_state - device instance specific data
29 * @us_w: actual spi_device to write config
30 * @us_r: actual spi_device to read back data
31 * @buf: transmit or receive buffer
32 * @buf_lock: mutex to protect tx and rx
33 **/
34 struct adis16060_state {
35 struct spi_device *us_w;
36 struct spi_device *us_r;
37 struct mutex buf_lock;
38
39 u8 buf[3] ____cacheline_aligned;
40 };
41
42 static struct iio_dev *adis16060_iio_dev;
43
adis16060_spi_write(struct iio_dev * indio_dev,u8 val)44 static int adis16060_spi_write(struct iio_dev *indio_dev, u8 val)
45 {
46 int ret;
47 struct adis16060_state *st = iio_priv(indio_dev);
48
49 mutex_lock(&st->buf_lock);
50 st->buf[2] = val; /* The last 8 bits clocked in are latched */
51 ret = spi_write(st->us_w, st->buf, 3);
52 mutex_unlock(&st->buf_lock);
53
54 return ret;
55 }
56
adis16060_spi_read(struct iio_dev * indio_dev,u16 * val)57 static int adis16060_spi_read(struct iio_dev *indio_dev, u16 *val)
58 {
59 int ret;
60 struct adis16060_state *st = iio_priv(indio_dev);
61
62 mutex_lock(&st->buf_lock);
63
64 ret = spi_read(st->us_r, st->buf, 3);
65
66 /* The internal successive approximation ADC begins the
67 * conversion process on the falling edge of MSEL1 and
68 * starts to place data MSB first on the DOUT line at
69 * the 6th falling edge of SCLK
70 */
71 if (ret == 0)
72 *val = ((st->buf[0] & 0x3) << 12) |
73 (st->buf[1] << 4) |
74 ((st->buf[2] >> 4) & 0xF);
75 mutex_unlock(&st->buf_lock);
76
77 return ret;
78 }
79
adis16060_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)80 static int adis16060_read_raw(struct iio_dev *indio_dev,
81 struct iio_chan_spec const *chan,
82 int *val, int *val2,
83 long mask)
84 {
85 u16 tval = 0;
86 int ret;
87
88 switch (mask) {
89 case 0:
90 /* Take the iio_dev status lock */
91 mutex_lock(&indio_dev->mlock);
92 ret = adis16060_spi_write(indio_dev, chan->address);
93 if (ret < 0) {
94 mutex_unlock(&indio_dev->mlock);
95 return ret;
96 }
97 ret = adis16060_spi_read(indio_dev, &tval);
98 mutex_unlock(&indio_dev->mlock);
99 *val = tval;
100 return IIO_VAL_INT;
101 case IIO_CHAN_INFO_OFFSET:
102 *val = -7;
103 *val2 = 461117;
104 return IIO_VAL_INT_PLUS_MICRO;
105 case IIO_CHAN_INFO_SCALE:
106 *val = 0;
107 *val2 = 34000;
108 return IIO_VAL_INT_PLUS_MICRO;
109 }
110
111 return -EINVAL;
112 }
113
114 static const struct iio_info adis16060_info = {
115 .read_raw = &adis16060_read_raw,
116 .driver_module = THIS_MODULE,
117 };
118
119 static const struct iio_chan_spec adis16060_channels[] = {
120 {
121 .type = IIO_ANGL_VEL,
122 .modified = 1,
123 .channel2 = IIO_MOD_Z,
124 .address = ADIS16060_GYRO,
125 }, {
126 .type = IIO_VOLTAGE,
127 .indexed = 1,
128 .channel = 0,
129 .address = ADIS16060_AIN1,
130 }, {
131 .type = IIO_VOLTAGE,
132 .indexed = 1,
133 .channel = 1,
134 .address = ADIS16060_AIN2,
135 }, {
136 .type = IIO_TEMP,
137 .indexed = 1,
138 .channel = 0,
139 .info_mask = IIO_CHAN_INFO_OFFSET_SEPARATE_BIT |
140 IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
141 .address = ADIS16060_TEMP_OUT,
142 }
143 };
144
adis16060_r_probe(struct spi_device * spi)145 static int __devinit adis16060_r_probe(struct spi_device *spi)
146 {
147 int ret;
148 struct adis16060_state *st;
149 struct iio_dev *indio_dev;
150
151 /* setup the industrialio driver allocated elements */
152 indio_dev = iio_allocate_device(sizeof(*st));
153 if (indio_dev == NULL) {
154 ret = -ENOMEM;
155 goto error_ret;
156 }
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 = iio_device_register(indio_dev);
171 if (ret)
172 goto error_free_dev;
173
174 adis16060_iio_dev = indio_dev;
175 return 0;
176
177 error_free_dev:
178 iio_free_device(indio_dev);
179 error_ret:
180 return ret;
181 }
182
183 /* fixme, confirm ordering in this function */
adis16060_r_remove(struct spi_device * spi)184 static int adis16060_r_remove(struct spi_device *spi)
185 {
186 iio_device_unregister(spi_get_drvdata(spi));
187 iio_free_device(spi_get_drvdata(spi));
188
189 return 0;
190 }
191
adis16060_w_probe(struct spi_device * spi)192 static int __devinit adis16060_w_probe(struct spi_device *spi)
193 {
194 int ret;
195 struct iio_dev *indio_dev = adis16060_iio_dev;
196 struct adis16060_state *st;
197 if (!indio_dev) {
198 ret = -ENODEV;
199 goto error_ret;
200 }
201 st = iio_priv(indio_dev);
202 spi_set_drvdata(spi, indio_dev);
203 st->us_w = spi;
204 return 0;
205
206 error_ret:
207 return ret;
208 }
209
adis16060_w_remove(struct spi_device * spi)210 static int adis16060_w_remove(struct spi_device *spi)
211 {
212 return 0;
213 }
214
215 static struct spi_driver adis16060_r_driver = {
216 .driver = {
217 .name = "adis16060_r",
218 .owner = THIS_MODULE,
219 },
220 .probe = adis16060_r_probe,
221 .remove = __devexit_p(adis16060_r_remove),
222 };
223
224 static struct spi_driver adis16060_w_driver = {
225 .driver = {
226 .name = "adis16060_w",
227 .owner = THIS_MODULE,
228 },
229 .probe = adis16060_w_probe,
230 .remove = __devexit_p(adis16060_w_remove),
231 };
232
adis16060_init(void)233 static __init int adis16060_init(void)
234 {
235 int ret;
236
237 ret = spi_register_driver(&adis16060_r_driver);
238 if (ret < 0)
239 return ret;
240
241 ret = spi_register_driver(&adis16060_w_driver);
242 if (ret < 0) {
243 spi_unregister_driver(&adis16060_r_driver);
244 return ret;
245 }
246
247 return 0;
248 }
249 module_init(adis16060_init);
250
adis16060_exit(void)251 static __exit void adis16060_exit(void)
252 {
253 spi_unregister_driver(&adis16060_w_driver);
254 spi_unregister_driver(&adis16060_r_driver);
255 }
256 module_exit(adis16060_exit);
257
258 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
259 MODULE_DESCRIPTION("Analog Devices ADIS16060 Yaw Rate Gyroscope Driver");
260 MODULE_LICENSE("GPL v2");
261