1
2
3
4
5
6
7
8#include <linux/device.h>
9#include <linux/kernel.h>
10#include <linux/slab.h>
11#include <linux/sysfs.h>
12#include <linux/spi/spi.h>
13#include <linux/regulator/consumer.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <linux/interrupt.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
23#include <linux/iio/trigger_consumer.h>
24#include <linux/iio/triggered_buffer.h>
25
26#include <linux/platform_data/ad7887.h>
27
28#define AD7887_REF_DIS BIT(5)
29#define AD7887_DUAL BIT(4)
30#define AD7887_CH_AIN1 BIT(3)
31#define AD7887_CH_AIN0 0
32#define AD7887_PM_MODE1 0
33#define AD7887_PM_MODE2 1
34#define AD7887_PM_MODE3 2
35#define AD7887_PM_MODE4 3
36
37enum ad7887_channels {
38 AD7887_CH0,
39 AD7887_CH0_CH1,
40 AD7887_CH1,
41};
42
43
44
45
46
47
48
49
50
51struct ad7887_chip_info {
52 u16 int_vref_mv;
53 const struct iio_chan_spec *channels;
54 unsigned int num_channels;
55 const struct iio_chan_spec *dual_channels;
56 unsigned int num_dual_channels;
57};
58
59struct ad7887_state {
60 struct spi_device *spi;
61 const struct ad7887_chip_info *chip_info;
62 struct regulator *reg;
63 struct spi_transfer xfer[4];
64 struct spi_message msg[3];
65 struct spi_message *ring_msg;
66 unsigned char tx_cmd_buf[4];
67
68
69
70
71
72
73
74 unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)]
75 ____cacheline_aligned;
76};
77
78enum ad7887_supported_device_ids {
79 ID_AD7887
80};
81
82static int ad7887_ring_preenable(struct iio_dev *indio_dev)
83{
84 struct ad7887_state *st = iio_priv(indio_dev);
85
86
87 switch (*indio_dev->active_scan_mask) {
88 case (1 << 0):
89 st->ring_msg = &st->msg[AD7887_CH0];
90 break;
91 case (1 << 1):
92 st->ring_msg = &st->msg[AD7887_CH1];
93
94 spi_sync(st->spi, st->ring_msg);
95 break;
96 case ((1 << 1) | (1 << 0)):
97 st->ring_msg = &st->msg[AD7887_CH0_CH1];
98 break;
99 }
100
101 return 0;
102}
103
104static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
105{
106 struct ad7887_state *st = iio_priv(indio_dev);
107
108
109 return spi_sync(st->spi, &st->msg[AD7887_CH0]);
110}
111
112static irqreturn_t ad7887_trigger_handler(int irq, void *p)
113{
114 struct iio_poll_func *pf = p;
115 struct iio_dev *indio_dev = pf->indio_dev;
116 struct ad7887_state *st = iio_priv(indio_dev);
117 int b_sent;
118
119 b_sent = spi_sync(st->spi, st->ring_msg);
120 if (b_sent)
121 goto done;
122
123 iio_push_to_buffers_with_timestamp(indio_dev, st->data,
124 iio_get_time_ns(indio_dev));
125done:
126 iio_trigger_notify_done(indio_dev->trig);
127
128 return IRQ_HANDLED;
129}
130
131static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = {
132 .preenable = &ad7887_ring_preenable,
133 .postdisable = &ad7887_ring_postdisable,
134};
135
136static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
137{
138 int ret = spi_sync(st->spi, &st->msg[ch]);
139 if (ret)
140 return ret;
141
142 return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
143}
144
145static int ad7887_read_raw(struct iio_dev *indio_dev,
146 struct iio_chan_spec const *chan,
147 int *val,
148 int *val2,
149 long m)
150{
151 int ret;
152 struct ad7887_state *st = iio_priv(indio_dev);
153
154 switch (m) {
155 case IIO_CHAN_INFO_RAW:
156 ret = iio_device_claim_direct_mode(indio_dev);
157 if (ret)
158 return ret;
159 ret = ad7887_scan_direct(st, chan->address);
160 iio_device_release_direct_mode(indio_dev);
161
162 if (ret < 0)
163 return ret;
164 *val = ret >> chan->scan_type.shift;
165 *val &= GENMASK(chan->scan_type.realbits - 1, 0);
166 return IIO_VAL_INT;
167 case IIO_CHAN_INFO_SCALE:
168 if (st->reg) {
169 *val = regulator_get_voltage(st->reg);
170 if (*val < 0)
171 return *val;
172 *val /= 1000;
173 } else {
174 *val = st->chip_info->int_vref_mv;
175 }
176
177 *val2 = chan->scan_type.realbits;
178
179 return IIO_VAL_FRACTIONAL_LOG2;
180 }
181 return -EINVAL;
182}
183
184#define AD7887_CHANNEL(x) { \
185 .type = IIO_VOLTAGE, \
186 .indexed = 1, \
187 .channel = (x), \
188 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
189 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
190 .address = (x), \
191 .scan_index = (x), \
192 .scan_type = { \
193 .sign = 'u', \
194 .realbits = 12, \
195 .storagebits = 16, \
196 .shift = 0, \
197 .endianness = IIO_BE, \
198 }, \
199}
200
201static const struct iio_chan_spec ad7887_channels[] = {
202 AD7887_CHANNEL(0),
203 IIO_CHAN_SOFT_TIMESTAMP(1),
204};
205
206static const struct iio_chan_spec ad7887_dual_channels[] = {
207 AD7887_CHANNEL(0),
208 AD7887_CHANNEL(1),
209 IIO_CHAN_SOFT_TIMESTAMP(2),
210};
211
212static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
213
214
215
216 [ID_AD7887] = {
217 .channels = ad7887_channels,
218 .num_channels = ARRAY_SIZE(ad7887_channels),
219 .dual_channels = ad7887_dual_channels,
220 .num_dual_channels = ARRAY_SIZE(ad7887_dual_channels),
221 .int_vref_mv = 2500,
222 },
223};
224
225static const struct iio_info ad7887_info = {
226 .read_raw = &ad7887_read_raw,
227};
228
229static void ad7887_reg_disable(void *data)
230{
231 struct regulator *reg = data;
232
233 regulator_disable(reg);
234}
235
236static int ad7887_probe(struct spi_device *spi)
237{
238 struct ad7887_platform_data *pdata = spi->dev.platform_data;
239 struct ad7887_state *st;
240 struct iio_dev *indio_dev;
241 uint8_t mode;
242 int ret;
243
244 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
245 if (indio_dev == NULL)
246 return -ENOMEM;
247
248 st = iio_priv(indio_dev);
249
250 st->reg = devm_regulator_get_optional(&spi->dev, "vref");
251 if (IS_ERR(st->reg)) {
252 if (PTR_ERR(st->reg) != -ENODEV)
253 return PTR_ERR(st->reg);
254
255 st->reg = NULL;
256 }
257
258 if (st->reg) {
259 ret = regulator_enable(st->reg);
260 if (ret)
261 return ret;
262
263 ret = devm_add_action_or_reset(&spi->dev, ad7887_reg_disable, st->reg);
264 if (ret)
265 return ret;
266 }
267
268 st->chip_info =
269 &ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
270
271 st->spi = spi;
272
273 indio_dev->name = spi_get_device_id(spi)->name;
274 indio_dev->info = &ad7887_info;
275 indio_dev->modes = INDIO_DIRECT_MODE;
276
277
278
279 mode = AD7887_PM_MODE4;
280 if (!st->reg)
281 mode |= AD7887_REF_DIS;
282 if (pdata && pdata->en_dual)
283 mode |= AD7887_DUAL;
284
285 st->tx_cmd_buf[0] = AD7887_CH_AIN0 | mode;
286
287 st->xfer[0].rx_buf = &st->data[0];
288 st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
289 st->xfer[0].len = 2;
290
291 spi_message_init(&st->msg[AD7887_CH0]);
292 spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
293
294 if (pdata && pdata->en_dual) {
295 st->tx_cmd_buf[2] = AD7887_CH_AIN1 | mode;
296
297 st->xfer[1].rx_buf = &st->data[0];
298 st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
299 st->xfer[1].len = 2;
300
301 st->xfer[2].rx_buf = &st->data[2];
302 st->xfer[2].tx_buf = &st->tx_cmd_buf[0];
303 st->xfer[2].len = 2;
304
305 spi_message_init(&st->msg[AD7887_CH0_CH1]);
306 spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
307 spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
308
309 st->xfer[3].rx_buf = &st->data[2];
310 st->xfer[3].tx_buf = &st->tx_cmd_buf[2];
311 st->xfer[3].len = 2;
312
313 spi_message_init(&st->msg[AD7887_CH1]);
314 spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
315
316 indio_dev->channels = st->chip_info->dual_channels;
317 indio_dev->num_channels = st->chip_info->num_dual_channels;
318 } else {
319 indio_dev->channels = st->chip_info->channels;
320 indio_dev->num_channels = st->chip_info->num_channels;
321 }
322
323 ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
324 &iio_pollfunc_store_time,
325 &ad7887_trigger_handler, &ad7887_ring_setup_ops);
326 if (ret)
327 return ret;
328
329 return devm_iio_device_register(&spi->dev, indio_dev);
330}
331
332static const struct spi_device_id ad7887_id[] = {
333 {"ad7887", ID_AD7887},
334 {}
335};
336MODULE_DEVICE_TABLE(spi, ad7887_id);
337
338static struct spi_driver ad7887_driver = {
339 .driver = {
340 .name = "ad7887",
341 },
342 .probe = ad7887_probe,
343 .id_table = ad7887_id,
344};
345module_spi_driver(ad7887_driver);
346
347MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
348MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
349MODULE_LICENSE("GPL v2");
350