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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/delay.h>
17#include <linux/module.h>
18#include <linux/interrupt.h>
19#include <linux/bitops.h>
20
21#include <linux/iio/iio.h>
22#include <linux/iio/sysfs.h>
23#include <linux/iio/buffer.h>
24#include <linux/iio/trigger_consumer.h>
25#include <linux/iio/triggered_buffer.h>
26
27#include <linux/platform_data/ad7298.h>
28
29#define AD7298_WRITE BIT(15)
30#define AD7298_REPEAT BIT(14)
31#define AD7298_CH(x) BIT(13 - (x))
32#define AD7298_TSENSE BIT(5)
33#define AD7298_EXTREF BIT(2)
34#define AD7298_TAVG BIT(1)
35#define AD7298_PDD BIT(0)
36
37#define AD7298_MAX_CHAN 8
38#define AD7298_INTREF_mV 2500
39
40#define AD7298_CH_TEMP 9
41
42struct ad7298_state {
43 struct spi_device *spi;
44 struct regulator *reg;
45 unsigned ext_ref;
46 struct spi_transfer ring_xfer[10];
47 struct spi_transfer scan_single_xfer[3];
48 struct spi_message ring_msg;
49 struct spi_message scan_single_msg;
50
51
52
53
54 __be16 rx_buf[12] ____cacheline_aligned;
55 __be16 tx_buf[2];
56};
57
58#define AD7298_V_CHAN(index) \
59 { \
60 .type = IIO_VOLTAGE, \
61 .indexed = 1, \
62 .channel = index, \
63 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
64 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
65 .address = index, \
66 .scan_index = index, \
67 .scan_type = { \
68 .sign = 'u', \
69 .realbits = 12, \
70 .storagebits = 16, \
71 .endianness = IIO_BE, \
72 }, \
73 }
74
75static const struct iio_chan_spec ad7298_channels[] = {
76 {
77 .type = IIO_TEMP,
78 .indexed = 1,
79 .channel = 0,
80 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
81 BIT(IIO_CHAN_INFO_SCALE) |
82 BIT(IIO_CHAN_INFO_OFFSET),
83 .address = AD7298_CH_TEMP,
84 .scan_index = -1,
85 .scan_type = {
86 .sign = 's',
87 .realbits = 32,
88 .storagebits = 32,
89 },
90 },
91 AD7298_V_CHAN(0),
92 AD7298_V_CHAN(1),
93 AD7298_V_CHAN(2),
94 AD7298_V_CHAN(3),
95 AD7298_V_CHAN(4),
96 AD7298_V_CHAN(5),
97 AD7298_V_CHAN(6),
98 AD7298_V_CHAN(7),
99 IIO_CHAN_SOFT_TIMESTAMP(8),
100};
101
102
103
104
105static int ad7298_update_scan_mode(struct iio_dev *indio_dev,
106 const unsigned long *active_scan_mask)
107{
108 struct ad7298_state *st = iio_priv(indio_dev);
109 int i, m;
110 unsigned short command;
111 int scan_count;
112
113
114 scan_count = bitmap_weight(active_scan_mask, indio_dev->masklength);
115
116 command = AD7298_WRITE | st->ext_ref;
117
118 for (i = 0, m = AD7298_CH(0); i < AD7298_MAX_CHAN; i++, m >>= 1)
119 if (test_bit(i, active_scan_mask))
120 command |= m;
121
122 st->tx_buf[0] = cpu_to_be16(command);
123
124
125 st->ring_xfer[0].tx_buf = &st->tx_buf[0];
126 st->ring_xfer[0].len = 2;
127 st->ring_xfer[0].cs_change = 1;
128 st->ring_xfer[1].tx_buf = &st->tx_buf[1];
129 st->ring_xfer[1].len = 2;
130 st->ring_xfer[1].cs_change = 1;
131
132 spi_message_init(&st->ring_msg);
133 spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
134 spi_message_add_tail(&st->ring_xfer[1], &st->ring_msg);
135
136 for (i = 0; i < scan_count; i++) {
137 st->ring_xfer[i + 2].rx_buf = &st->rx_buf[i];
138 st->ring_xfer[i + 2].len = 2;
139 st->ring_xfer[i + 2].cs_change = 1;
140 spi_message_add_tail(&st->ring_xfer[i + 2], &st->ring_msg);
141 }
142
143 st->ring_xfer[i + 1].cs_change = 0;
144
145 return 0;
146}
147
148
149
150
151
152
153
154static irqreturn_t ad7298_trigger_handler(int irq, void *p)
155{
156 struct iio_poll_func *pf = p;
157 struct iio_dev *indio_dev = pf->indio_dev;
158 struct ad7298_state *st = iio_priv(indio_dev);
159 int b_sent;
160
161 b_sent = spi_sync(st->spi, &st->ring_msg);
162 if (b_sent)
163 goto done;
164
165 iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
166 iio_get_time_ns());
167
168done:
169 iio_trigger_notify_done(indio_dev->trig);
170
171 return IRQ_HANDLED;
172}
173
174static int ad7298_scan_direct(struct ad7298_state *st, unsigned ch)
175{
176 int ret;
177 st->tx_buf[0] = cpu_to_be16(AD7298_WRITE | st->ext_ref |
178 (AD7298_CH(0) >> ch));
179
180 ret = spi_sync(st->spi, &st->scan_single_msg);
181 if (ret)
182 return ret;
183
184 return be16_to_cpu(st->rx_buf[0]);
185}
186
187static int ad7298_scan_temp(struct ad7298_state *st, int *val)
188{
189 int ret;
190 __be16 buf;
191
192 buf = cpu_to_be16(AD7298_WRITE | AD7298_TSENSE |
193 AD7298_TAVG | st->ext_ref);
194
195 ret = spi_write(st->spi, (u8 *)&buf, 2);
196 if (ret)
197 return ret;
198
199 buf = cpu_to_be16(0);
200
201 ret = spi_write(st->spi, (u8 *)&buf, 2);
202 if (ret)
203 return ret;
204
205 usleep_range(101, 1000);
206
207 ret = spi_read(st->spi, (u8 *)&buf, 2);
208 if (ret)
209 return ret;
210
211 *val = sign_extend32(be16_to_cpu(buf), 11);
212
213 return 0;
214}
215
216static int ad7298_get_ref_voltage(struct ad7298_state *st)
217{
218 int vref;
219
220 if (st->ext_ref) {
221 vref = regulator_get_voltage(st->reg);
222 if (vref < 0)
223 return vref;
224
225 return vref / 1000;
226 } else {
227 return AD7298_INTREF_mV;
228 }
229}
230
231static int ad7298_read_raw(struct iio_dev *indio_dev,
232 struct iio_chan_spec const *chan,
233 int *val,
234 int *val2,
235 long m)
236{
237 int ret;
238 struct ad7298_state *st = iio_priv(indio_dev);
239
240 switch (m) {
241 case IIO_CHAN_INFO_RAW:
242 mutex_lock(&indio_dev->mlock);
243 if (indio_dev->currentmode == INDIO_BUFFER_TRIGGERED) {
244 ret = -EBUSY;
245 } else {
246 if (chan->address == AD7298_CH_TEMP)
247 ret = ad7298_scan_temp(st, val);
248 else
249 ret = ad7298_scan_direct(st, chan->address);
250 }
251 mutex_unlock(&indio_dev->mlock);
252
253 if (ret < 0)
254 return ret;
255
256 if (chan->address != AD7298_CH_TEMP)
257 *val = ret & GENMASK(chan->scan_type.realbits - 1, 0);
258
259 return IIO_VAL_INT;
260 case IIO_CHAN_INFO_SCALE:
261 switch (chan->type) {
262 case IIO_VOLTAGE:
263 *val = ad7298_get_ref_voltage(st);
264 *val2 = chan->scan_type.realbits;
265 return IIO_VAL_FRACTIONAL_LOG2;
266 case IIO_TEMP:
267 *val = ad7298_get_ref_voltage(st);
268 *val2 = 10;
269 return IIO_VAL_FRACTIONAL;
270 default:
271 return -EINVAL;
272 }
273 case IIO_CHAN_INFO_OFFSET:
274 *val = 1093 - 2732500 / ad7298_get_ref_voltage(st);
275 return IIO_VAL_INT;
276 }
277 return -EINVAL;
278}
279
280static const struct iio_info ad7298_info = {
281 .read_raw = &ad7298_read_raw,
282 .update_scan_mode = ad7298_update_scan_mode,
283 .driver_module = THIS_MODULE,
284};
285
286static int ad7298_probe(struct spi_device *spi)
287{
288 struct ad7298_platform_data *pdata = spi->dev.platform_data;
289 struct ad7298_state *st;
290 struct iio_dev *indio_dev;
291 int ret;
292
293 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
294 if (indio_dev == NULL)
295 return -ENOMEM;
296
297 st = iio_priv(indio_dev);
298
299 if (pdata && pdata->ext_ref)
300 st->ext_ref = AD7298_EXTREF;
301
302 if (st->ext_ref) {
303 st->reg = devm_regulator_get(&spi->dev, "vref");
304 if (IS_ERR(st->reg))
305 return PTR_ERR(st->reg);
306
307 ret = regulator_enable(st->reg);
308 if (ret)
309 return ret;
310 }
311
312 spi_set_drvdata(spi, indio_dev);
313
314 st->spi = spi;
315
316 indio_dev->name = spi_get_device_id(spi)->name;
317 indio_dev->dev.parent = &spi->dev;
318 indio_dev->modes = INDIO_DIRECT_MODE;
319 indio_dev->channels = ad7298_channels;
320 indio_dev->num_channels = ARRAY_SIZE(ad7298_channels);
321 indio_dev->info = &ad7298_info;
322
323
324
325 st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
326 st->scan_single_xfer[0].len = 2;
327 st->scan_single_xfer[0].cs_change = 1;
328 st->scan_single_xfer[1].tx_buf = &st->tx_buf[1];
329 st->scan_single_xfer[1].len = 2;
330 st->scan_single_xfer[1].cs_change = 1;
331 st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
332 st->scan_single_xfer[2].len = 2;
333
334 spi_message_init(&st->scan_single_msg);
335 spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
336 spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
337 spi_message_add_tail(&st->scan_single_xfer[2], &st->scan_single_msg);
338
339 ret = iio_triggered_buffer_setup(indio_dev, NULL,
340 &ad7298_trigger_handler, NULL);
341 if (ret)
342 goto error_disable_reg;
343
344 ret = iio_device_register(indio_dev);
345 if (ret)
346 goto error_cleanup_ring;
347
348 return 0;
349
350error_cleanup_ring:
351 iio_triggered_buffer_cleanup(indio_dev);
352error_disable_reg:
353 if (st->ext_ref)
354 regulator_disable(st->reg);
355
356 return ret;
357}
358
359static int ad7298_remove(struct spi_device *spi)
360{
361 struct iio_dev *indio_dev = spi_get_drvdata(spi);
362 struct ad7298_state *st = iio_priv(indio_dev);
363
364 iio_device_unregister(indio_dev);
365 iio_triggered_buffer_cleanup(indio_dev);
366 if (st->ext_ref)
367 regulator_disable(st->reg);
368
369 return 0;
370}
371
372static const struct spi_device_id ad7298_id[] = {
373 {"ad7298", 0},
374 {}
375};
376MODULE_DEVICE_TABLE(spi, ad7298_id);
377
378static struct spi_driver ad7298_driver = {
379 .driver = {
380 .name = "ad7298",
381 .owner = THIS_MODULE,
382 },
383 .probe = ad7298_probe,
384 .remove = ad7298_remove,
385 .id_table = ad7298_id,
386};
387module_spi_driver(ad7298_driver);
388
389MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
390MODULE_DESCRIPTION("Analog Devices AD7298 ADC");
391MODULE_LICENSE("GPL v2");
392
