1 /*
2 * AD7606 SPI ADC driver
3 *
4 * Copyright 2011 Analog Devices Inc.
5 *
6 * Licensed under the GPL-2.
7 */
8
9 #include <linux/interrupt.h>
10 #include <linux/device.h>
11 #include <linux/kernel.h>
12 #include <linux/slab.h>
13 #include <linux/sysfs.h>
14 #include <linux/regulator/consumer.h>
15 #include <linux/err.h>
16 #include <linux/gpio.h>
17 #include <linux/delay.h>
18 #include <linux/sched.h>
19 #include <linux/module.h>
20
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24
25 #include "ad7606.h"
26
ad7606_reset(struct ad7606_state * st)27 int ad7606_reset(struct ad7606_state *st)
28 {
29 if (gpio_is_valid(st->pdata->gpio_reset)) {
30 gpio_set_value(st->pdata->gpio_reset, 1);
31 ndelay(100); /* t_reset >= 100ns */
32 gpio_set_value(st->pdata->gpio_reset, 0);
33 return 0;
34 }
35
36 return -ENODEV;
37 }
38
ad7606_scan_direct(struct iio_dev * indio_dev,unsigned ch)39 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned ch)
40 {
41 struct ad7606_state *st = iio_priv(indio_dev);
42 int ret;
43
44 st->done = false;
45 gpio_set_value(st->pdata->gpio_convst, 1);
46
47 ret = wait_event_interruptible(st->wq_data_avail, st->done);
48 if (ret)
49 goto error_ret;
50
51 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
52 ret = st->bops->read_block(st->dev, 1, st->data);
53 if (ret)
54 goto error_ret;
55 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
56 /* This should never happen */
57 ad7606_reset(st);
58 ret = -EIO;
59 goto error_ret;
60 }
61 ret = st->bops->read_block(st->dev,
62 st->chip_info->num_channels - 1, &st->data[1]);
63 if (ret)
64 goto error_ret;
65 } else {
66 ret = st->bops->read_block(st->dev,
67 st->chip_info->num_channels, st->data);
68 if (ret)
69 goto error_ret;
70 }
71
72 ret = st->data[ch];
73
74 error_ret:
75 gpio_set_value(st->pdata->gpio_convst, 0);
76
77 return ret;
78 }
79
ad7606_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long m)80 static int ad7606_read_raw(struct iio_dev *indio_dev,
81 struct iio_chan_spec const *chan,
82 int *val,
83 int *val2,
84 long m)
85 {
86 int ret;
87 struct ad7606_state *st = iio_priv(indio_dev);
88
89 switch (m) {
90 case IIO_CHAN_INFO_RAW:
91 mutex_lock(&indio_dev->mlock);
92 if (iio_buffer_enabled(indio_dev))
93 ret = -EBUSY;
94 else
95 ret = ad7606_scan_direct(indio_dev, chan->address);
96 mutex_unlock(&indio_dev->mlock);
97
98 if (ret < 0)
99 return ret;
100 *val = (short) ret;
101 return IIO_VAL_INT;
102 case IIO_CHAN_INFO_SCALE:
103 *val = st->range * 2;
104 *val2 = st->chip_info->channels[0].scan_type.realbits;
105 return IIO_VAL_FRACTIONAL_LOG2;
106 }
107 return -EINVAL;
108 }
109
ad7606_show_range(struct device * dev,struct device_attribute * attr,char * buf)110 static ssize_t ad7606_show_range(struct device *dev,
111 struct device_attribute *attr, char *buf)
112 {
113 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
114 struct ad7606_state *st = iio_priv(indio_dev);
115
116 return sprintf(buf, "%u\n", st->range);
117 }
118
ad7606_store_range(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)119 static ssize_t ad7606_store_range(struct device *dev,
120 struct device_attribute *attr, const char *buf, size_t count)
121 {
122 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
123 struct ad7606_state *st = iio_priv(indio_dev);
124 unsigned long lval;
125 int ret;
126
127 ret = kstrtoul(buf, 10, &lval);
128 if (ret)
129 return ret;
130
131 if (!(lval == 5000 || lval == 10000)) {
132 dev_err(dev, "range is not supported\n");
133 return -EINVAL;
134 }
135 mutex_lock(&indio_dev->mlock);
136 gpio_set_value(st->pdata->gpio_range, lval == 10000);
137 st->range = lval;
138 mutex_unlock(&indio_dev->mlock);
139
140 return count;
141 }
142
143 static IIO_DEVICE_ATTR(in_voltage_range, S_IRUGO | S_IWUSR,
144 ad7606_show_range, ad7606_store_range, 0);
145 static IIO_CONST_ATTR(in_voltage_range_available, "5000 10000");
146
ad7606_show_oversampling_ratio(struct device * dev,struct device_attribute * attr,char * buf)147 static ssize_t ad7606_show_oversampling_ratio(struct device *dev,
148 struct device_attribute *attr, char *buf)
149 {
150 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
151 struct ad7606_state *st = iio_priv(indio_dev);
152
153 return sprintf(buf, "%u\n", st->oversampling);
154 }
155
ad7606_oversampling_get_index(unsigned val)156 static int ad7606_oversampling_get_index(unsigned val)
157 {
158 unsigned char supported[] = {0, 2, 4, 8, 16, 32, 64};
159 int i;
160
161 for (i = 0; i < ARRAY_SIZE(supported); i++)
162 if (val == supported[i])
163 return i;
164
165 return -EINVAL;
166 }
167
ad7606_store_oversampling_ratio(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)168 static ssize_t ad7606_store_oversampling_ratio(struct device *dev,
169 struct device_attribute *attr, const char *buf, size_t count)
170 {
171 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
172 struct ad7606_state *st = iio_priv(indio_dev);
173 unsigned long lval;
174 int ret;
175
176 ret = kstrtoul(buf, 10, &lval);
177 if (ret)
178 return ret;
179
180 ret = ad7606_oversampling_get_index(lval);
181 if (ret < 0) {
182 dev_err(dev, "oversampling %lu is not supported\n", lval);
183 return ret;
184 }
185
186 mutex_lock(&indio_dev->mlock);
187 gpio_set_value(st->pdata->gpio_os0, (ret >> 0) & 1);
188 gpio_set_value(st->pdata->gpio_os1, (ret >> 1) & 1);
189 gpio_set_value(st->pdata->gpio_os1, (ret >> 2) & 1);
190 st->oversampling = lval;
191 mutex_unlock(&indio_dev->mlock);
192
193 return count;
194 }
195
196 static IIO_DEVICE_ATTR(oversampling_ratio, S_IRUGO | S_IWUSR,
197 ad7606_show_oversampling_ratio,
198 ad7606_store_oversampling_ratio, 0);
199 static IIO_CONST_ATTR(oversampling_ratio_available, "0 2 4 8 16 32 64");
200
201 static struct attribute *ad7606_attributes_os_and_range[] = {
202 &iio_dev_attr_in_voltage_range.dev_attr.attr,
203 &iio_const_attr_in_voltage_range_available.dev_attr.attr,
204 &iio_dev_attr_oversampling_ratio.dev_attr.attr,
205 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
206 NULL,
207 };
208
209 static const struct attribute_group ad7606_attribute_group_os_and_range = {
210 .attrs = ad7606_attributes_os_and_range,
211 };
212
213 static struct attribute *ad7606_attributes_os[] = {
214 &iio_dev_attr_oversampling_ratio.dev_attr.attr,
215 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
216 NULL,
217 };
218
219 static const struct attribute_group ad7606_attribute_group_os = {
220 .attrs = ad7606_attributes_os,
221 };
222
223 static struct attribute *ad7606_attributes_range[] = {
224 &iio_dev_attr_in_voltage_range.dev_attr.attr,
225 &iio_const_attr_in_voltage_range_available.dev_attr.attr,
226 NULL,
227 };
228
229 static const struct attribute_group ad7606_attribute_group_range = {
230 .attrs = ad7606_attributes_range,
231 };
232
233 #define AD7606_CHANNEL(num) \
234 { \
235 .type = IIO_VOLTAGE, \
236 .indexed = 1, \
237 .channel = num, \
238 .address = num, \
239 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
240 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
241 .scan_index = num, \
242 .scan_type = { \
243 .sign = 's', \
244 .realbits = 16, \
245 .storagebits = 16, \
246 .endianness = IIO_CPU, \
247 }, \
248 }
249
250 static const struct iio_chan_spec ad7606_8_channels[] = {
251 AD7606_CHANNEL(0),
252 AD7606_CHANNEL(1),
253 AD7606_CHANNEL(2),
254 AD7606_CHANNEL(3),
255 AD7606_CHANNEL(4),
256 AD7606_CHANNEL(5),
257 AD7606_CHANNEL(6),
258 AD7606_CHANNEL(7),
259 IIO_CHAN_SOFT_TIMESTAMP(8),
260 };
261
262 static const struct iio_chan_spec ad7606_6_channels[] = {
263 AD7606_CHANNEL(0),
264 AD7606_CHANNEL(1),
265 AD7606_CHANNEL(2),
266 AD7606_CHANNEL(3),
267 AD7606_CHANNEL(4),
268 AD7606_CHANNEL(5),
269 IIO_CHAN_SOFT_TIMESTAMP(6),
270 };
271
272 static const struct iio_chan_spec ad7606_4_channels[] = {
273 AD7606_CHANNEL(0),
274 AD7606_CHANNEL(1),
275 AD7606_CHANNEL(2),
276 AD7606_CHANNEL(3),
277 IIO_CHAN_SOFT_TIMESTAMP(4),
278 };
279
280 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
281 /*
282 * More devices added in future
283 */
284 [ID_AD7606_8] = {
285 .name = "ad7606",
286 .int_vref_mv = 2500,
287 .channels = ad7606_8_channels,
288 .num_channels = 8,
289 },
290 [ID_AD7606_6] = {
291 .name = "ad7606-6",
292 .int_vref_mv = 2500,
293 .channels = ad7606_6_channels,
294 .num_channels = 6,
295 },
296 [ID_AD7606_4] = {
297 .name = "ad7606-4",
298 .int_vref_mv = 2500,
299 .channels = ad7606_4_channels,
300 .num_channels = 4,
301 },
302 };
303
ad7606_request_gpios(struct ad7606_state * st)304 static int ad7606_request_gpios(struct ad7606_state *st)
305 {
306 struct gpio gpio_array[3] = {
307 [0] = {
308 .gpio = st->pdata->gpio_os0,
309 .flags = GPIOF_DIR_OUT | ((st->oversampling & 1) ?
310 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
311 .label = "AD7606_OS0",
312 },
313 [1] = {
314 .gpio = st->pdata->gpio_os1,
315 .flags = GPIOF_DIR_OUT | ((st->oversampling & 2) ?
316 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
317 .label = "AD7606_OS1",
318 },
319 [2] = {
320 .gpio = st->pdata->gpio_os2,
321 .flags = GPIOF_DIR_OUT | ((st->oversampling & 4) ?
322 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
323 .label = "AD7606_OS2",
324 },
325 };
326 int ret;
327
328 if (gpio_is_valid(st->pdata->gpio_convst)) {
329 ret = gpio_request_one(st->pdata->gpio_convst,
330 GPIOF_OUT_INIT_LOW,
331 "AD7606_CONVST");
332 if (ret) {
333 dev_err(st->dev, "failed to request GPIO CONVST\n");
334 goto error_ret;
335 }
336 } else {
337 ret = -EIO;
338 goto error_ret;
339 }
340
341 if (gpio_is_valid(st->pdata->gpio_os0) &&
342 gpio_is_valid(st->pdata->gpio_os1) &&
343 gpio_is_valid(st->pdata->gpio_os2)) {
344 ret = gpio_request_array(gpio_array, ARRAY_SIZE(gpio_array));
345 if (ret < 0)
346 goto error_free_convst;
347 }
348
349 if (gpio_is_valid(st->pdata->gpio_reset)) {
350 ret = gpio_request_one(st->pdata->gpio_reset,
351 GPIOF_OUT_INIT_LOW,
352 "AD7606_RESET");
353 if (ret < 0)
354 goto error_free_os;
355 }
356
357 if (gpio_is_valid(st->pdata->gpio_range)) {
358 ret = gpio_request_one(st->pdata->gpio_range, GPIOF_DIR_OUT |
359 ((st->range == 10000) ? GPIOF_INIT_HIGH :
360 GPIOF_INIT_LOW), "AD7606_RANGE");
361 if (ret < 0)
362 goto error_free_reset;
363 }
364 if (gpio_is_valid(st->pdata->gpio_stby)) {
365 ret = gpio_request_one(st->pdata->gpio_stby,
366 GPIOF_OUT_INIT_HIGH,
367 "AD7606_STBY");
368 if (ret < 0)
369 goto error_free_range;
370 }
371
372 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
373 ret = gpio_request_one(st->pdata->gpio_frstdata, GPIOF_IN,
374 "AD7606_FRSTDATA");
375 if (ret < 0)
376 goto error_free_stby;
377 }
378
379 return 0;
380
381 error_free_stby:
382 if (gpio_is_valid(st->pdata->gpio_stby))
383 gpio_free(st->pdata->gpio_stby);
384 error_free_range:
385 if (gpio_is_valid(st->pdata->gpio_range))
386 gpio_free(st->pdata->gpio_range);
387 error_free_reset:
388 if (gpio_is_valid(st->pdata->gpio_reset))
389 gpio_free(st->pdata->gpio_reset);
390 error_free_os:
391 if (gpio_is_valid(st->pdata->gpio_os0) &&
392 gpio_is_valid(st->pdata->gpio_os1) &&
393 gpio_is_valid(st->pdata->gpio_os2))
394 gpio_free_array(gpio_array, ARRAY_SIZE(gpio_array));
395 error_free_convst:
396 gpio_free(st->pdata->gpio_convst);
397 error_ret:
398 return ret;
399 }
400
ad7606_free_gpios(struct ad7606_state * st)401 static void ad7606_free_gpios(struct ad7606_state *st)
402 {
403 if (gpio_is_valid(st->pdata->gpio_frstdata))
404 gpio_free(st->pdata->gpio_frstdata);
405 if (gpio_is_valid(st->pdata->gpio_stby))
406 gpio_free(st->pdata->gpio_stby);
407 if (gpio_is_valid(st->pdata->gpio_range))
408 gpio_free(st->pdata->gpio_range);
409 if (gpio_is_valid(st->pdata->gpio_reset))
410 gpio_free(st->pdata->gpio_reset);
411 if (gpio_is_valid(st->pdata->gpio_os0) &&
412 gpio_is_valid(st->pdata->gpio_os1) &&
413 gpio_is_valid(st->pdata->gpio_os2)) {
414 gpio_free(st->pdata->gpio_os2);
415 gpio_free(st->pdata->gpio_os1);
416 gpio_free(st->pdata->gpio_os0);
417 }
418 gpio_free(st->pdata->gpio_convst);
419 }
420
421 /**
422 * Interrupt handler
423 */
ad7606_interrupt(int irq,void * dev_id)424 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
425 {
426 struct iio_dev *indio_dev = dev_id;
427 struct ad7606_state *st = iio_priv(indio_dev);
428
429 if (iio_buffer_enabled(indio_dev)) {
430 schedule_work(&st->poll_work);
431 } else {
432 st->done = true;
433 wake_up_interruptible(&st->wq_data_avail);
434 }
435
436 return IRQ_HANDLED;
437 };
438
439 static const struct iio_info ad7606_info_no_os_or_range = {
440 .driver_module = THIS_MODULE,
441 .read_raw = &ad7606_read_raw,
442 };
443
444 static const struct iio_info ad7606_info_os_and_range = {
445 .driver_module = THIS_MODULE,
446 .read_raw = &ad7606_read_raw,
447 .attrs = &ad7606_attribute_group_os_and_range,
448 };
449
450 static const struct iio_info ad7606_info_os = {
451 .driver_module = THIS_MODULE,
452 .read_raw = &ad7606_read_raw,
453 .attrs = &ad7606_attribute_group_os,
454 };
455
456 static const struct iio_info ad7606_info_range = {
457 .driver_module = THIS_MODULE,
458 .read_raw = &ad7606_read_raw,
459 .attrs = &ad7606_attribute_group_range,
460 };
461
ad7606_probe(struct device * dev,int irq,void __iomem * base_address,unsigned id,const struct ad7606_bus_ops * bops)462 struct iio_dev *ad7606_probe(struct device *dev, int irq,
463 void __iomem *base_address,
464 unsigned id,
465 const struct ad7606_bus_ops *bops)
466 {
467 struct ad7606_platform_data *pdata = dev->platform_data;
468 struct ad7606_state *st;
469 int ret;
470 struct iio_dev *indio_dev;
471
472 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
473 if (!indio_dev)
474 return ERR_PTR(-ENOMEM);
475
476 st = iio_priv(indio_dev);
477
478 st->dev = dev;
479 st->bops = bops;
480 st->base_address = base_address;
481 st->range = pdata->default_range == 10000 ? 10000 : 5000;
482
483 ret = ad7606_oversampling_get_index(pdata->default_os);
484 if (ret < 0) {
485 dev_warn(dev, "oversampling %d is not supported\n",
486 pdata->default_os);
487 st->oversampling = 0;
488 } else {
489 st->oversampling = pdata->default_os;
490 }
491
492 st->reg = devm_regulator_get(dev, "vcc");
493 if (!IS_ERR(st->reg)) {
494 ret = regulator_enable(st->reg);
495 if (ret)
496 return ERR_PTR(ret);
497 }
498
499 st->pdata = pdata;
500 st->chip_info = &ad7606_chip_info_tbl[id];
501
502 indio_dev->dev.parent = dev;
503 if (gpio_is_valid(st->pdata->gpio_os0) &&
504 gpio_is_valid(st->pdata->gpio_os1) &&
505 gpio_is_valid(st->pdata->gpio_os2)) {
506 if (gpio_is_valid(st->pdata->gpio_range))
507 indio_dev->info = &ad7606_info_os_and_range;
508 else
509 indio_dev->info = &ad7606_info_os;
510 } else {
511 if (gpio_is_valid(st->pdata->gpio_range))
512 indio_dev->info = &ad7606_info_range;
513 else
514 indio_dev->info = &ad7606_info_no_os_or_range;
515 }
516 indio_dev->modes = INDIO_DIRECT_MODE;
517 indio_dev->name = st->chip_info->name;
518 indio_dev->channels = st->chip_info->channels;
519 indio_dev->num_channels = st->chip_info->num_channels;
520
521 init_waitqueue_head(&st->wq_data_avail);
522
523 ret = ad7606_request_gpios(st);
524 if (ret)
525 goto error_disable_reg;
526
527 ret = ad7606_reset(st);
528 if (ret)
529 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
530
531 ret = request_irq(irq, ad7606_interrupt,
532 IRQF_TRIGGER_FALLING, st->chip_info->name, indio_dev);
533 if (ret)
534 goto error_free_gpios;
535
536 ret = ad7606_register_ring_funcs_and_init(indio_dev);
537 if (ret)
538 goto error_free_irq;
539
540 ret = iio_device_register(indio_dev);
541 if (ret)
542 goto error_unregister_ring;
543
544 return indio_dev;
545 error_unregister_ring:
546 ad7606_ring_cleanup(indio_dev);
547
548 error_free_irq:
549 free_irq(irq, indio_dev);
550
551 error_free_gpios:
552 ad7606_free_gpios(st);
553
554 error_disable_reg:
555 if (!IS_ERR(st->reg))
556 regulator_disable(st->reg);
557 return ERR_PTR(ret);
558 }
559
ad7606_remove(struct iio_dev * indio_dev,int irq)560 int ad7606_remove(struct iio_dev *indio_dev, int irq)
561 {
562 struct ad7606_state *st = iio_priv(indio_dev);
563
564 iio_device_unregister(indio_dev);
565 ad7606_ring_cleanup(indio_dev);
566
567 free_irq(irq, indio_dev);
568 if (!IS_ERR(st->reg))
569 regulator_disable(st->reg);
570
571 ad7606_free_gpios(st);
572
573 return 0;
574 }
575
ad7606_suspend(struct iio_dev * indio_dev)576 void ad7606_suspend(struct iio_dev *indio_dev)
577 {
578 struct ad7606_state *st = iio_priv(indio_dev);
579
580 if (gpio_is_valid(st->pdata->gpio_stby)) {
581 if (gpio_is_valid(st->pdata->gpio_range))
582 gpio_set_value(st->pdata->gpio_range, 1);
583 gpio_set_value(st->pdata->gpio_stby, 0);
584 }
585 }
586
ad7606_resume(struct iio_dev * indio_dev)587 void ad7606_resume(struct iio_dev *indio_dev)
588 {
589 struct ad7606_state *st = iio_priv(indio_dev);
590
591 if (gpio_is_valid(st->pdata->gpio_stby)) {
592 if (gpio_is_valid(st->pdata->gpio_range))
593 gpio_set_value(st->pdata->gpio_range,
594 st->range == 10000);
595
596 gpio_set_value(st->pdata->gpio_stby, 1);
597 ad7606_reset(st);
598 }
599 }
600
601 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
602 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
603 MODULE_LICENSE("GPL v2");
604