1
2
3
4
5
6
7
8
9
10#include <linux/bitops.h>
11#include <linux/delay.h>
12#include <linux/device.h>
13#include <linux/gpio/consumer.h>
14#include <linux/module.h>
15#include <linux/mod_devicetable.h>
16#include <linux/mutex.h>
17#include <linux/spi/spi.h>
18#include <linux/sysfs.h>
19#include <linux/types.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23
24#define DRV_NAME "ad2s1200"
25
26
27#define AD2S1200_HZ 8192000
28
29#define AD2S1200_TSCLK (1000000000 / AD2S1200_HZ)
30
31
32
33
34
35
36
37
38
39struct ad2s1200_state {
40 struct mutex lock;
41 struct spi_device *sdev;
42 struct gpio_desc *sample;
43 struct gpio_desc *rdvel;
44 __be16 rx ____cacheline_aligned;
45};
46
47static int ad2s1200_read_raw(struct iio_dev *indio_dev,
48 struct iio_chan_spec const *chan,
49 int *val,
50 int *val2,
51 long m)
52{
53 struct ad2s1200_state *st = iio_priv(indio_dev);
54 int ret;
55
56 switch (m) {
57 case IIO_CHAN_INFO_SCALE:
58 switch (chan->type) {
59 case IIO_ANGL:
60
61 *val = 0;
62 *val2 = 1534355;
63 return IIO_VAL_INT_PLUS_NANO;
64 case IIO_ANGL_VEL:
65
66 *val = 6;
67 *val2 = 283185;
68 return IIO_VAL_INT_PLUS_MICRO;
69 default:
70 return -EINVAL;
71 }
72 break;
73 case IIO_CHAN_INFO_RAW:
74 mutex_lock(&st->lock);
75 gpiod_set_value(st->sample, 0);
76
77
78 udelay(1);
79 gpiod_set_value(st->sample, 1);
80 gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
81
82 ret = spi_read(st->sdev, &st->rx, 2);
83 if (ret < 0) {
84 mutex_unlock(&st->lock);
85 return ret;
86 }
87
88 switch (chan->type) {
89 case IIO_ANGL:
90 *val = be16_to_cpup(&st->rx) >> 4;
91 break;
92 case IIO_ANGL_VEL:
93 *val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
94 break;
95 default:
96 mutex_unlock(&st->lock);
97 return -EINVAL;
98 }
99
100
101 udelay(1);
102 mutex_unlock(&st->lock);
103
104 return IIO_VAL_INT;
105 default:
106 break;
107 }
108
109 return -EINVAL;
110}
111
112static const struct iio_chan_spec ad2s1200_channels[] = {
113 {
114 .type = IIO_ANGL,
115 .indexed = 1,
116 .channel = 0,
117 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
118 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
119 }, {
120 .type = IIO_ANGL_VEL,
121 .indexed = 1,
122 .channel = 0,
123 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
124 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
125 }
126};
127
128static const struct iio_info ad2s1200_info = {
129 .read_raw = ad2s1200_read_raw,
130};
131
132static int ad2s1200_probe(struct spi_device *spi)
133{
134 struct ad2s1200_state *st;
135 struct iio_dev *indio_dev;
136 int ret;
137
138 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
139 if (!indio_dev)
140 return -ENOMEM;
141
142 spi_set_drvdata(spi, indio_dev);
143 st = iio_priv(indio_dev);
144 mutex_init(&st->lock);
145 st->sdev = spi;
146
147 st->sample = devm_gpiod_get(&spi->dev, "adi,sample", GPIOD_OUT_LOW);
148 if (IS_ERR(st->sample)) {
149 dev_err(&spi->dev, "Failed to claim SAMPLE gpio: err=%ld\n",
150 PTR_ERR(st->sample));
151 return PTR_ERR(st->sample);
152 }
153
154 st->rdvel = devm_gpiod_get(&spi->dev, "adi,rdvel", GPIOD_OUT_LOW);
155 if (IS_ERR(st->rdvel)) {
156 dev_err(&spi->dev, "Failed to claim RDVEL gpio: err=%ld\n",
157 PTR_ERR(st->rdvel));
158 return PTR_ERR(st->rdvel);
159 }
160
161 indio_dev->info = &ad2s1200_info;
162 indio_dev->modes = INDIO_DIRECT_MODE;
163 indio_dev->channels = ad2s1200_channels;
164 indio_dev->num_channels = ARRAY_SIZE(ad2s1200_channels);
165 indio_dev->name = spi_get_device_id(spi)->name;
166
167 spi->max_speed_hz = AD2S1200_HZ;
168 spi->mode = SPI_MODE_3;
169 ret = spi_setup(spi);
170
171 if (ret < 0) {
172 dev_err(&spi->dev, "spi_setup failed!\n");
173 return ret;
174 }
175
176 return devm_iio_device_register(&spi->dev, indio_dev);
177}
178
179static const struct of_device_id ad2s1200_of_match[] = {
180 { .compatible = "adi,ad2s1200", },
181 { .compatible = "adi,ad2s1205", },
182 { }
183};
184MODULE_DEVICE_TABLE(of, ad2s1200_of_match);
185
186static const struct spi_device_id ad2s1200_id[] = {
187 { "ad2s1200" },
188 { "ad2s1205" },
189 {}
190};
191MODULE_DEVICE_TABLE(spi, ad2s1200_id);
192
193static struct spi_driver ad2s1200_driver = {
194 .driver = {
195 .name = DRV_NAME,
196 .of_match_table = ad2s1200_of_match,
197 },
198 .probe = ad2s1200_probe,
199 .id_table = ad2s1200_id,
200};
201module_spi_driver(ad2s1200_driver);
202
203MODULE_AUTHOR("David Veenstra <davidjulianveenstra@gmail.com>");
204MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
205MODULE_DESCRIPTION("Analog Devices AD2S1200/1205 Resolver to Digital SPI driver");
206MODULE_LICENSE("GPL v2");
207
