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 "../iio.h"
22 #include "../sysfs.h"
23 #include "../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 unsigned int scale_uv;
89
90 switch (m) {
91 case 0:
92 mutex_lock(&indio_dev->mlock);
93 if (iio_buffer_enabled(indio_dev))
94 ret = -EBUSY;
95 else
96 ret = ad7606_scan_direct(indio_dev, chan->address);
97 mutex_unlock(&indio_dev->mlock);
98
99 if (ret < 0)
100 return ret;
101 *val = (short) ret;
102 return IIO_VAL_INT;
103 case IIO_CHAN_INFO_SCALE:
104 scale_uv = (st->range * 1000 * 2)
105 >> st->chip_info->channels[0].scan_type.realbits;
106 *val = scale_uv / 1000;
107 *val2 = (scale_uv % 1000) * 1000;
108 return IIO_VAL_INT_PLUS_MICRO;
109 }
110 return -EINVAL;
111 }
112
ad7606_show_range(struct device * dev,struct device_attribute * attr,char * buf)113 static ssize_t ad7606_show_range(struct device *dev,
114 struct device_attribute *attr, char *buf)
115 {
116 struct iio_dev *indio_dev = dev_get_drvdata(dev);
117 struct ad7606_state *st = iio_priv(indio_dev);
118
119 return sprintf(buf, "%u\n", st->range);
120 }
121
ad7606_store_range(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)122 static ssize_t ad7606_store_range(struct device *dev,
123 struct device_attribute *attr, const char *buf, size_t count)
124 {
125 struct iio_dev *indio_dev = dev_get_drvdata(dev);
126 struct ad7606_state *st = iio_priv(indio_dev);
127 unsigned long lval;
128
129 if (strict_strtoul(buf, 10, &lval))
130 return -EINVAL;
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_get_drvdata(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_get_drvdata(dev);
172 struct ad7606_state *st = iio_priv(indio_dev);
173 unsigned long lval;
174 int ret;
175
176 if (strict_strtoul(buf, 10, &lval))
177 return -EINVAL;
178
179 ret = ad7606_oversampling_get_index(lval);
180 if (ret < 0) {
181 dev_err(dev, "oversampling %lu is not supported\n", lval);
182 return ret;
183 }
184
185 mutex_lock(&indio_dev->mlock);
186 gpio_set_value(st->pdata->gpio_os0, (ret >> 0) & 1);
187 gpio_set_value(st->pdata->gpio_os1, (ret >> 1) & 1);
188 gpio_set_value(st->pdata->gpio_os1, (ret >> 2) & 1);
189 st->oversampling = lval;
190 mutex_unlock(&indio_dev->mlock);
191
192 return count;
193 }
194
195 static IIO_DEVICE_ATTR(oversampling_ratio, S_IRUGO | S_IWUSR,
196 ad7606_show_oversampling_ratio,
197 ad7606_store_oversampling_ratio, 0);
198 static IIO_CONST_ATTR(oversampling_ratio_available, "0 2 4 8 16 32 64");
199
200 static struct attribute *ad7606_attributes[] = {
201 &iio_dev_attr_in_voltage_range.dev_attr.attr,
202 &iio_const_attr_in_voltage_range_available.dev_attr.attr,
203 &iio_dev_attr_oversampling_ratio.dev_attr.attr,
204 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
205 NULL,
206 };
207
ad7606_attr_is_visible(struct kobject * kobj,struct attribute * attr,int n)208 static umode_t ad7606_attr_is_visible(struct kobject *kobj,
209 struct attribute *attr, int n)
210 {
211 struct device *dev = container_of(kobj, struct device, kobj);
212 struct iio_dev *indio_dev = dev_get_drvdata(dev);
213 struct ad7606_state *st = iio_priv(indio_dev);
214
215 umode_t mode = attr->mode;
216
217 if (!(gpio_is_valid(st->pdata->gpio_os0) &&
218 gpio_is_valid(st->pdata->gpio_os1) &&
219 gpio_is_valid(st->pdata->gpio_os2)) &&
220 (attr == &iio_dev_attr_oversampling_ratio.dev_attr.attr ||
221 attr ==
222 &iio_const_attr_oversampling_ratio_available.dev_attr.attr))
223 mode = 0;
224 else if (!gpio_is_valid(st->pdata->gpio_range) &&
225 (attr == &iio_dev_attr_in_voltage_range.dev_attr.attr ||
226 attr ==
227 &iio_const_attr_in_voltage_range_available.dev_attr.attr))
228 mode = 0;
229
230 return mode;
231 }
232
233 static const struct attribute_group ad7606_attribute_group = {
234 .attrs = ad7606_attributes,
235 .is_visible = ad7606_attr_is_visible,
236 };
237
238 #define AD7606_CHANNEL(num) \
239 { \
240 .type = IIO_VOLTAGE, \
241 .indexed = 1, \
242 .channel = num, \
243 .address = num, \
244 .scan_index = num, \
245 .scan_type = IIO_ST('s', 16, 16, 0), \
246 }
247
248 static struct iio_chan_spec ad7606_8_channels[] = {
249 AD7606_CHANNEL(0),
250 AD7606_CHANNEL(1),
251 AD7606_CHANNEL(2),
252 AD7606_CHANNEL(3),
253 AD7606_CHANNEL(4),
254 AD7606_CHANNEL(5),
255 AD7606_CHANNEL(6),
256 AD7606_CHANNEL(7),
257 IIO_CHAN_SOFT_TIMESTAMP(8),
258 };
259
260 static struct iio_chan_spec ad7606_6_channels[] = {
261 AD7606_CHANNEL(0),
262 AD7606_CHANNEL(1),
263 AD7606_CHANNEL(2),
264 AD7606_CHANNEL(3),
265 AD7606_CHANNEL(4),
266 AD7606_CHANNEL(5),
267 IIO_CHAN_SOFT_TIMESTAMP(6),
268 };
269
270 static struct iio_chan_spec ad7606_4_channels[] = {
271 AD7606_CHANNEL(0),
272 AD7606_CHANNEL(1),
273 AD7606_CHANNEL(2),
274 AD7606_CHANNEL(3),
275 IIO_CHAN_SOFT_TIMESTAMP(4),
276 };
277
278 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
279 /*
280 * More devices added in future
281 */
282 [ID_AD7606_8] = {
283 .name = "ad7606",
284 .int_vref_mv = 2500,
285 .channels = ad7606_8_channels,
286 .num_channels = 8,
287 },
288 [ID_AD7606_6] = {
289 .name = "ad7606-6",
290 .int_vref_mv = 2500,
291 .channels = ad7606_6_channels,
292 .num_channels = 6,
293 },
294 [ID_AD7606_4] = {
295 .name = "ad7606-4",
296 .int_vref_mv = 2500,
297 .channels = ad7606_4_channels,
298 .num_channels = 4,
299 },
300 };
301
ad7606_request_gpios(struct ad7606_state * st)302 static int ad7606_request_gpios(struct ad7606_state *st)
303 {
304 struct gpio gpio_array[3] = {
305 [0] = {
306 .gpio = st->pdata->gpio_os0,
307 .flags = GPIOF_DIR_OUT | ((st->oversampling & 1) ?
308 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
309 .label = "AD7606_OS0",
310 },
311 [1] = {
312 .gpio = st->pdata->gpio_os1,
313 .flags = GPIOF_DIR_OUT | ((st->oversampling & 2) ?
314 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
315 .label = "AD7606_OS1",
316 },
317 [2] = {
318 .gpio = st->pdata->gpio_os2,
319 .flags = GPIOF_DIR_OUT | ((st->oversampling & 4) ?
320 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
321 .label = "AD7606_OS2",
322 },
323 };
324 int ret;
325
326 if (gpio_is_valid(st->pdata->gpio_convst)) {
327 ret = gpio_request_one(st->pdata->gpio_convst,
328 GPIOF_OUT_INIT_LOW,
329 "AD7606_CONVST");
330 if (ret) {
331 dev_err(st->dev, "failed to request GPIO CONVST\n");
332 goto error_ret;
333 }
334 } else {
335 ret = -EIO;
336 goto error_ret;
337 }
338
339 if (gpio_is_valid(st->pdata->gpio_os0) &&
340 gpio_is_valid(st->pdata->gpio_os1) &&
341 gpio_is_valid(st->pdata->gpio_os2)) {
342 ret = gpio_request_array(gpio_array, ARRAY_SIZE(gpio_array));
343 if (ret < 0)
344 goto error_free_convst;
345 }
346
347 if (gpio_is_valid(st->pdata->gpio_reset)) {
348 ret = gpio_request_one(st->pdata->gpio_reset,
349 GPIOF_OUT_INIT_LOW,
350 "AD7606_RESET");
351 if (ret < 0)
352 goto error_free_os;
353 }
354
355 if (gpio_is_valid(st->pdata->gpio_range)) {
356 ret = gpio_request_one(st->pdata->gpio_range, GPIOF_DIR_OUT |
357 ((st->range == 10000) ? GPIOF_INIT_HIGH :
358 GPIOF_INIT_LOW), "AD7606_RANGE");
359 if (ret < 0)
360 goto error_free_reset;
361 }
362 if (gpio_is_valid(st->pdata->gpio_stby)) {
363 ret = gpio_request_one(st->pdata->gpio_stby,
364 GPIOF_OUT_INIT_HIGH,
365 "AD7606_STBY");
366 if (ret < 0)
367 goto error_free_range;
368 }
369
370 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
371 ret = gpio_request_one(st->pdata->gpio_frstdata, GPIOF_IN,
372 "AD7606_FRSTDATA");
373 if (ret < 0)
374 goto error_free_stby;
375 }
376
377 return 0;
378
379 error_free_stby:
380 if (gpio_is_valid(st->pdata->gpio_stby))
381 gpio_free(st->pdata->gpio_stby);
382 error_free_range:
383 if (gpio_is_valid(st->pdata->gpio_range))
384 gpio_free(st->pdata->gpio_range);
385 error_free_reset:
386 if (gpio_is_valid(st->pdata->gpio_reset))
387 gpio_free(st->pdata->gpio_reset);
388 error_free_os:
389 if (gpio_is_valid(st->pdata->gpio_os0) &&
390 gpio_is_valid(st->pdata->gpio_os1) &&
391 gpio_is_valid(st->pdata->gpio_os2))
392 gpio_free_array(gpio_array, ARRAY_SIZE(gpio_array));
393 error_free_convst:
394 gpio_free(st->pdata->gpio_convst);
395 error_ret:
396 return ret;
397 }
398
ad7606_free_gpios(struct ad7606_state * st)399 static void ad7606_free_gpios(struct ad7606_state *st)
400 {
401 if (gpio_is_valid(st->pdata->gpio_frstdata))
402 gpio_free(st->pdata->gpio_frstdata);
403 if (gpio_is_valid(st->pdata->gpio_stby))
404 gpio_free(st->pdata->gpio_stby);
405 if (gpio_is_valid(st->pdata->gpio_range))
406 gpio_free(st->pdata->gpio_range);
407 if (gpio_is_valid(st->pdata->gpio_reset))
408 gpio_free(st->pdata->gpio_reset);
409 if (gpio_is_valid(st->pdata->gpio_os0) &&
410 gpio_is_valid(st->pdata->gpio_os1) &&
411 gpio_is_valid(st->pdata->gpio_os2)) {
412 gpio_free(st->pdata->gpio_os2);
413 gpio_free(st->pdata->gpio_os1);
414 gpio_free(st->pdata->gpio_os0);
415 }
416 gpio_free(st->pdata->gpio_convst);
417 }
418
419 /**
420 * Interrupt handler
421 */
ad7606_interrupt(int irq,void * dev_id)422 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
423 {
424 struct iio_dev *indio_dev = dev_id;
425 struct ad7606_state *st = iio_priv(indio_dev);
426
427 if (iio_buffer_enabled(indio_dev)) {
428 if (!work_pending(&st->poll_work))
429 schedule_work(&st->poll_work);
430 } else {
431 st->done = true;
432 wake_up_interruptible(&st->wq_data_avail);
433 }
434
435 return IRQ_HANDLED;
436 };
437
438 static const struct iio_info ad7606_info = {
439 .driver_module = THIS_MODULE,
440 .read_raw = &ad7606_read_raw,
441 .attrs = &ad7606_attribute_group,
442 };
443
ad7606_probe(struct device * dev,int irq,void __iomem * base_address,unsigned id,const struct ad7606_bus_ops * bops)444 struct iio_dev *ad7606_probe(struct device *dev, int irq,
445 void __iomem *base_address,
446 unsigned id,
447 const struct ad7606_bus_ops *bops)
448 {
449 struct ad7606_platform_data *pdata = dev->platform_data;
450 struct ad7606_state *st;
451 int ret;
452 struct iio_dev *indio_dev = iio_allocate_device(sizeof(*st));
453
454 if (indio_dev == NULL) {
455 ret = -ENOMEM;
456 goto error_ret;
457 }
458
459 st = iio_priv(indio_dev);
460
461 st->dev = dev;
462 st->bops = bops;
463 st->base_address = base_address;
464 st->range = pdata->default_range == 10000 ? 10000 : 5000;
465
466 ret = ad7606_oversampling_get_index(pdata->default_os);
467 if (ret < 0) {
468 dev_warn(dev, "oversampling %d is not supported\n",
469 pdata->default_os);
470 st->oversampling = 0;
471 } else {
472 st->oversampling = pdata->default_os;
473 }
474
475 st->reg = regulator_get(dev, "vcc");
476 if (!IS_ERR(st->reg)) {
477 ret = regulator_enable(st->reg);
478 if (ret)
479 goto error_put_reg;
480 }
481
482 st->pdata = pdata;
483 st->chip_info = &ad7606_chip_info_tbl[id];
484
485 indio_dev->dev.parent = dev;
486 indio_dev->info = &ad7606_info;
487 indio_dev->modes = INDIO_DIRECT_MODE;
488 indio_dev->name = st->chip_info->name;
489 indio_dev->channels = st->chip_info->channels;
490 indio_dev->num_channels = st->chip_info->num_channels;
491
492 init_waitqueue_head(&st->wq_data_avail);
493
494 ret = ad7606_request_gpios(st);
495 if (ret)
496 goto error_disable_reg;
497
498 ret = ad7606_reset(st);
499 if (ret)
500 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
501
502 ret = request_irq(irq, ad7606_interrupt,
503 IRQF_TRIGGER_FALLING, st->chip_info->name, indio_dev);
504 if (ret)
505 goto error_free_gpios;
506
507 ret = ad7606_register_ring_funcs_and_init(indio_dev);
508 if (ret)
509 goto error_free_irq;
510
511 ret = iio_buffer_register(indio_dev,
512 indio_dev->channels,
513 indio_dev->num_channels);
514 if (ret)
515 goto error_cleanup_ring;
516 ret = iio_device_register(indio_dev);
517 if (ret)
518 goto error_unregister_ring;
519
520 return indio_dev;
521 error_unregister_ring:
522 iio_buffer_unregister(indio_dev);
523
524 error_cleanup_ring:
525 ad7606_ring_cleanup(indio_dev);
526
527 error_free_irq:
528 free_irq(irq, indio_dev);
529
530 error_free_gpios:
531 ad7606_free_gpios(st);
532
533 error_disable_reg:
534 if (!IS_ERR(st->reg))
535 regulator_disable(st->reg);
536 error_put_reg:
537 if (!IS_ERR(st->reg))
538 regulator_put(st->reg);
539 iio_free_device(indio_dev);
540 error_ret:
541 return ERR_PTR(ret);
542 }
543
ad7606_remove(struct iio_dev * indio_dev,int irq)544 int ad7606_remove(struct iio_dev *indio_dev, int irq)
545 {
546 struct ad7606_state *st = iio_priv(indio_dev);
547
548 iio_device_unregister(indio_dev);
549 iio_buffer_unregister(indio_dev);
550 ad7606_ring_cleanup(indio_dev);
551
552 free_irq(irq, indio_dev);
553 if (!IS_ERR(st->reg)) {
554 regulator_disable(st->reg);
555 regulator_put(st->reg);
556 }
557
558 ad7606_free_gpios(st);
559 iio_free_device(indio_dev);
560
561 return 0;
562 }
563
ad7606_suspend(struct iio_dev * indio_dev)564 void ad7606_suspend(struct iio_dev *indio_dev)
565 {
566 struct ad7606_state *st = iio_priv(indio_dev);
567
568 if (gpio_is_valid(st->pdata->gpio_stby)) {
569 if (gpio_is_valid(st->pdata->gpio_range))
570 gpio_set_value(st->pdata->gpio_range, 1);
571 gpio_set_value(st->pdata->gpio_stby, 0);
572 }
573 }
574
ad7606_resume(struct iio_dev * indio_dev)575 void ad7606_resume(struct iio_dev *indio_dev)
576 {
577 struct ad7606_state *st = iio_priv(indio_dev);
578
579 if (gpio_is_valid(st->pdata->gpio_stby)) {
580 if (gpio_is_valid(st->pdata->gpio_range))
581 gpio_set_value(st->pdata->gpio_range,
582 st->range == 10000);
583
584 gpio_set_value(st->pdata->gpio_stby, 1);
585 ad7606_reset(st);
586 }
587 }
588
589 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
590 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
591 MODULE_LICENSE("GPL v2");
592