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9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/slab.h>
12#include <linux/sysfs.h>
13#include <linux/spi/spi.h>
14#include <linux/regulator/consumer.h>
15#include <linux/err.h>
16#include <linux/module.h>
17#include <linux/bitops.h>
18
19#include <linux/iio/iio.h>
20#include <linux/iio/sysfs.h>
21#include <linux/iio/buffer.h>
22#include <linux/iio/trigger_consumer.h>
23#include <linux/iio/triggered_buffer.h>
24
25struct ad7476_state;
26
27struct ad7476_chip_info {
28 unsigned int int_vref_uv;
29 struct iio_chan_spec channel[2];
30 void (*reset)(struct ad7476_state *);
31};
32
33struct ad7476_state {
34 struct spi_device *spi;
35 const struct ad7476_chip_info *chip_info;
36 struct regulator *reg;
37 struct spi_transfer xfer;
38 struct spi_message msg;
39
40
41
42
43
44
45 unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
46 ____cacheline_aligned;
47};
48
49enum ad7476_supported_device_ids {
50 ID_AD7091R,
51 ID_AD7276,
52 ID_AD7277,
53 ID_AD7278,
54 ID_AD7466,
55 ID_AD7467,
56 ID_AD7468,
57 ID_AD7495,
58 ID_AD7940,
59};
60
61static irqreturn_t ad7476_trigger_handler(int irq, void *p)
62{
63 struct iio_poll_func *pf = p;
64 struct iio_dev *indio_dev = pf->indio_dev;
65 struct ad7476_state *st = iio_priv(indio_dev);
66 int b_sent;
67
68 b_sent = spi_sync(st->spi, &st->msg);
69 if (b_sent < 0)
70 goto done;
71
72 iio_push_to_buffers_with_timestamp(indio_dev, st->data,
73 iio_get_time_ns());
74done:
75 iio_trigger_notify_done(indio_dev->trig);
76
77 return IRQ_HANDLED;
78}
79
80static void ad7091_reset(struct ad7476_state *st)
81{
82
83 spi_read(st->spi, st->data, 1);
84}
85
86static int ad7476_scan_direct(struct ad7476_state *st)
87{
88 int ret;
89
90 ret = spi_sync(st->spi, &st->msg);
91 if (ret)
92 return ret;
93
94 return be16_to_cpup((__be16 *)st->data);
95}
96
97static int ad7476_read_raw(struct iio_dev *indio_dev,
98 struct iio_chan_spec const *chan,
99 int *val,
100 int *val2,
101 long m)
102{
103 int ret;
104 struct ad7476_state *st = iio_priv(indio_dev);
105 int scale_uv;
106
107 switch (m) {
108 case IIO_CHAN_INFO_RAW:
109 mutex_lock(&indio_dev->mlock);
110 if (iio_buffer_enabled(indio_dev))
111 ret = -EBUSY;
112 else
113 ret = ad7476_scan_direct(st);
114 mutex_unlock(&indio_dev->mlock);
115
116 if (ret < 0)
117 return ret;
118 *val = (ret >> st->chip_info->channel[0].scan_type.shift) &
119 GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0);
120 return IIO_VAL_INT;
121 case IIO_CHAN_INFO_SCALE:
122 if (!st->chip_info->int_vref_uv) {
123 scale_uv = regulator_get_voltage(st->reg);
124 if (scale_uv < 0)
125 return scale_uv;
126 } else {
127 scale_uv = st->chip_info->int_vref_uv;
128 }
129 *val = scale_uv / 1000;
130 *val2 = chan->scan_type.realbits;
131 return IIO_VAL_FRACTIONAL_LOG2;
132 }
133 return -EINVAL;
134}
135
136#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
137 { \
138 .type = IIO_VOLTAGE, \
139 .indexed = 1, \
140 .info_mask_separate = _info_mask_sep, \
141 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
142 .scan_type = { \
143 .sign = 'u', \
144 .realbits = (bits), \
145 .storagebits = 16, \
146 .shift = (_shift), \
147 .endianness = IIO_BE, \
148 }, \
149}
150
151#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
152 BIT(IIO_CHAN_INFO_RAW))
153#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
154 BIT(IIO_CHAN_INFO_RAW))
155#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
156
157static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
158 [ID_AD7091R] = {
159 .channel[0] = AD7091R_CHAN(12),
160 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
161 .reset = ad7091_reset,
162 },
163 [ID_AD7276] = {
164 .channel[0] = AD7940_CHAN(12),
165 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
166 },
167 [ID_AD7277] = {
168 .channel[0] = AD7940_CHAN(10),
169 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
170 },
171 [ID_AD7278] = {
172 .channel[0] = AD7940_CHAN(8),
173 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
174 },
175 [ID_AD7466] = {
176 .channel[0] = AD7476_CHAN(12),
177 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
178 },
179 [ID_AD7467] = {
180 .channel[0] = AD7476_CHAN(10),
181 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
182 },
183 [ID_AD7468] = {
184 .channel[0] = AD7476_CHAN(8),
185 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
186 },
187 [ID_AD7495] = {
188 .channel[0] = AD7476_CHAN(12),
189 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
190 .int_vref_uv = 2500000,
191 },
192 [ID_AD7940] = {
193 .channel[0] = AD7940_CHAN(14),
194 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
195 },
196};
197
198static const struct iio_info ad7476_info = {
199 .driver_module = THIS_MODULE,
200 .read_raw = &ad7476_read_raw,
201};
202
203static int ad7476_probe(struct spi_device *spi)
204{
205 struct ad7476_state *st;
206 struct iio_dev *indio_dev;
207 int ret;
208
209 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
210 if (!indio_dev)
211 return -ENOMEM;
212
213 st = iio_priv(indio_dev);
214 st->chip_info =
215 &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
216
217 st->reg = devm_regulator_get(&spi->dev, "vcc");
218 if (IS_ERR(st->reg))
219 return PTR_ERR(st->reg);
220
221 ret = regulator_enable(st->reg);
222 if (ret)
223 return ret;
224
225 spi_set_drvdata(spi, indio_dev);
226
227 st->spi = spi;
228
229
230 indio_dev->dev.parent = &spi->dev;
231 indio_dev->name = spi_get_device_id(spi)->name;
232 indio_dev->modes = INDIO_DIRECT_MODE;
233 indio_dev->channels = st->chip_info->channel;
234 indio_dev->num_channels = 2;
235 indio_dev->info = &ad7476_info;
236
237
238 st->xfer.rx_buf = &st->data;
239 st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
240
241 spi_message_init(&st->msg);
242 spi_message_add_tail(&st->xfer, &st->msg);
243
244 ret = iio_triggered_buffer_setup(indio_dev, NULL,
245 &ad7476_trigger_handler, NULL);
246 if (ret)
247 goto error_disable_reg;
248
249 if (st->chip_info->reset)
250 st->chip_info->reset(st);
251
252 ret = iio_device_register(indio_dev);
253 if (ret)
254 goto error_ring_unregister;
255 return 0;
256
257error_ring_unregister:
258 iio_triggered_buffer_cleanup(indio_dev);
259error_disable_reg:
260 regulator_disable(st->reg);
261
262 return ret;
263}
264
265static int ad7476_remove(struct spi_device *spi)
266{
267 struct iio_dev *indio_dev = spi_get_drvdata(spi);
268 struct ad7476_state *st = iio_priv(indio_dev);
269
270 iio_device_unregister(indio_dev);
271 iio_triggered_buffer_cleanup(indio_dev);
272 regulator_disable(st->reg);
273
274 return 0;
275}
276
277static const struct spi_device_id ad7476_id[] = {
278 {"ad7091r", ID_AD7091R},
279 {"ad7273", ID_AD7277},
280 {"ad7274", ID_AD7276},
281 {"ad7276", ID_AD7276},
282 {"ad7277", ID_AD7277},
283 {"ad7278", ID_AD7278},
284 {"ad7466", ID_AD7466},
285 {"ad7467", ID_AD7467},
286 {"ad7468", ID_AD7468},
287 {"ad7475", ID_AD7466},
288 {"ad7476", ID_AD7466},
289 {"ad7476a", ID_AD7466},
290 {"ad7477", ID_AD7467},
291 {"ad7477a", ID_AD7467},
292 {"ad7478", ID_AD7468},
293 {"ad7478a", ID_AD7468},
294 {"ad7495", ID_AD7495},
295 {"ad7910", ID_AD7467},
296 {"ad7920", ID_AD7466},
297 {"ad7940", ID_AD7940},
298 {}
299};
300MODULE_DEVICE_TABLE(spi, ad7476_id);
301
302static struct spi_driver ad7476_driver = {
303 .driver = {
304 .name = "ad7476",
305 },
306 .probe = ad7476_probe,
307 .remove = ad7476_remove,
308 .id_table = ad7476_id,
309};
310module_spi_driver(ad7476_driver);
311
312MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
313MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
314MODULE_LICENSE("GPL v2");
315
