2 * AD7606 SPI ADC driver
4 * Copyright 2011 Analog Devices Inc.
6 * Licensed under the GPL-2.
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>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
27 int ad7606_reset(struct ad7606_state *st)
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);
39 int ad7606_read_samples(struct ad7606_state *st)
41 unsigned int num = st->chip_info->num_channels;
46 * The frstdata signal is set to high while and after reading the sample
47 * of the first channel and low for all other channels. This can be used
48 * to check that the incoming data is correctly aligned. During normal
49 * operation the data should never become unaligned, but some glitch or
50 * electrostatic discharge might cause an extra read or clock cycle.
51 * Monitoring the frstdata signal allows to recover from such failure
55 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
56 ret = st->bops->read_block(st->dev, 1, data);
60 if (!gpio_get_value(st->pdata->gpio_frstdata)) {
69 return st->bops->read_block(st->dev, num, data);
72 static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
74 struct ad7606_state *st = iio_priv(indio_dev);
78 gpio_set_value(st->pdata->gpio_convst, 1);
80 ret = wait_event_interruptible(st->wq_data_avail, st->done);
84 ret = ad7606_read_samples(st);
89 gpio_set_value(st->pdata->gpio_convst, 0);
94 static int ad7606_read_raw(struct iio_dev *indio_dev,
95 struct iio_chan_spec const *chan,
101 struct ad7606_state *st = iio_priv(indio_dev);
104 case IIO_CHAN_INFO_RAW:
105 ret = iio_device_claim_direct_mode(indio_dev);
109 ret = ad7606_scan_direct(indio_dev, chan->address);
110 iio_device_release_direct_mode(indio_dev);
116 case IIO_CHAN_INFO_SCALE:
117 *val = st->range * 2;
118 *val2 = st->chip_info->channels[0].scan_type.realbits;
119 return IIO_VAL_FRACTIONAL_LOG2;
120 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
121 *val = st->oversampling;
127 static ssize_t ad7606_show_range(struct device *dev,
128 struct device_attribute *attr, char *buf)
130 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
131 struct ad7606_state *st = iio_priv(indio_dev);
133 return sprintf(buf, "%u\n", st->range);
136 static ssize_t ad7606_store_range(struct device *dev,
137 struct device_attribute *attr,
138 const char *buf, size_t count)
140 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
141 struct ad7606_state *st = iio_priv(indio_dev);
145 ret = kstrtoul(buf, 10, &lval);
149 if (!(lval == 5000 || lval == 10000))
152 mutex_lock(&indio_dev->mlock);
153 gpio_set_value(st->pdata->gpio_range, lval == 10000);
155 mutex_unlock(&indio_dev->mlock);
160 static IIO_DEVICE_ATTR(in_voltage_range, S_IRUGO | S_IWUSR,
161 ad7606_show_range, ad7606_store_range, 0);
162 static IIO_CONST_ATTR(in_voltage_range_available, "5000 10000");
164 static int ad7606_oversampling_get_index(unsigned int val)
166 unsigned char supported[] = {1, 2, 4, 8, 16, 32, 64};
169 for (i = 0; i < ARRAY_SIZE(supported); i++)
170 if (val == supported[i])
176 static int ad7606_write_raw(struct iio_dev *indio_dev,
177 struct iio_chan_spec const *chan,
182 struct ad7606_state *st = iio_priv(indio_dev);
186 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
189 ret = ad7606_oversampling_get_index(val);
193 mutex_lock(&indio_dev->mlock);
194 gpio_set_value(st->pdata->gpio_os0, (ret >> 0) & 1);
195 gpio_set_value(st->pdata->gpio_os1, (ret >> 1) & 1);
196 gpio_set_value(st->pdata->gpio_os2, (ret >> 2) & 1);
197 st->oversampling = val;
198 mutex_unlock(&indio_dev->mlock);
205 static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64");
207 static struct attribute *ad7606_attributes_os_and_range[] = {
208 &iio_dev_attr_in_voltage_range.dev_attr.attr,
209 &iio_const_attr_in_voltage_range_available.dev_attr.attr,
210 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
214 static const struct attribute_group ad7606_attribute_group_os_and_range = {
215 .attrs = ad7606_attributes_os_and_range,
218 static struct attribute *ad7606_attributes_os[] = {
219 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
223 static const struct attribute_group ad7606_attribute_group_os = {
224 .attrs = ad7606_attributes_os,
227 static struct attribute *ad7606_attributes_range[] = {
228 &iio_dev_attr_in_voltage_range.dev_attr.attr,
229 &iio_const_attr_in_voltage_range_available.dev_attr.attr,
233 static const struct attribute_group ad7606_attribute_group_range = {
234 .attrs = ad7606_attributes_range,
237 #define AD7606_CHANNEL(num) \
239 .type = IIO_VOLTAGE, \
243 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
244 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
245 .info_mask_shared_by_all = \
246 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
252 .endianness = IIO_CPU, \
256 static const struct iio_chan_spec ad7606_channels[] = {
257 IIO_CHAN_SOFT_TIMESTAMP(8),
268 static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
270 * More devices added in future
273 .channels = ad7606_channels,
277 .channels = ad7606_channels,
281 .channels = ad7606_channels,
286 static int ad7606_request_gpios(struct ad7606_state *st)
288 struct gpio gpio_array[3] = {
290 .gpio = st->pdata->gpio_os0,
291 .flags = GPIOF_DIR_OUT | ((st->oversampling & 1) ?
292 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
293 .label = "AD7606_OS0",
296 .gpio = st->pdata->gpio_os1,
297 .flags = GPIOF_DIR_OUT | ((st->oversampling & 2) ?
298 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
299 .label = "AD7606_OS1",
302 .gpio = st->pdata->gpio_os2,
303 .flags = GPIOF_DIR_OUT | ((st->oversampling & 4) ?
304 GPIOF_INIT_HIGH : GPIOF_INIT_LOW),
305 .label = "AD7606_OS2",
310 if (gpio_is_valid(st->pdata->gpio_convst)) {
311 ret = gpio_request_one(st->pdata->gpio_convst,
315 dev_err(st->dev, "failed to request GPIO CONVST\n");
323 if (gpio_is_valid(st->pdata->gpio_os0) &&
324 gpio_is_valid(st->pdata->gpio_os1) &&
325 gpio_is_valid(st->pdata->gpio_os2)) {
326 ret = gpio_request_array(gpio_array, ARRAY_SIZE(gpio_array));
328 goto error_free_convst;
331 if (gpio_is_valid(st->pdata->gpio_reset)) {
332 ret = gpio_request_one(st->pdata->gpio_reset,
339 if (gpio_is_valid(st->pdata->gpio_range)) {
340 ret = gpio_request_one(st->pdata->gpio_range, GPIOF_DIR_OUT |
341 ((st->range == 10000) ? GPIOF_INIT_HIGH :
342 GPIOF_INIT_LOW), "AD7606_RANGE");
344 goto error_free_reset;
346 if (gpio_is_valid(st->pdata->gpio_stby)) {
347 ret = gpio_request_one(st->pdata->gpio_stby,
351 goto error_free_range;
354 if (gpio_is_valid(st->pdata->gpio_frstdata)) {
355 ret = gpio_request_one(st->pdata->gpio_frstdata, GPIOF_IN,
358 goto error_free_stby;
364 if (gpio_is_valid(st->pdata->gpio_stby))
365 gpio_free(st->pdata->gpio_stby);
367 if (gpio_is_valid(st->pdata->gpio_range))
368 gpio_free(st->pdata->gpio_range);
370 if (gpio_is_valid(st->pdata->gpio_reset))
371 gpio_free(st->pdata->gpio_reset);
373 if (gpio_is_valid(st->pdata->gpio_os0) &&
374 gpio_is_valid(st->pdata->gpio_os1) &&
375 gpio_is_valid(st->pdata->gpio_os2))
376 gpio_free_array(gpio_array, ARRAY_SIZE(gpio_array));
378 gpio_free(st->pdata->gpio_convst);
383 static void ad7606_free_gpios(struct ad7606_state *st)
385 if (gpio_is_valid(st->pdata->gpio_frstdata))
386 gpio_free(st->pdata->gpio_frstdata);
387 if (gpio_is_valid(st->pdata->gpio_stby))
388 gpio_free(st->pdata->gpio_stby);
389 if (gpio_is_valid(st->pdata->gpio_range))
390 gpio_free(st->pdata->gpio_range);
391 if (gpio_is_valid(st->pdata->gpio_reset))
392 gpio_free(st->pdata->gpio_reset);
393 if (gpio_is_valid(st->pdata->gpio_os0) &&
394 gpio_is_valid(st->pdata->gpio_os1) &&
395 gpio_is_valid(st->pdata->gpio_os2)) {
396 gpio_free(st->pdata->gpio_os2);
397 gpio_free(st->pdata->gpio_os1);
398 gpio_free(st->pdata->gpio_os0);
400 gpio_free(st->pdata->gpio_convst);
406 static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
408 struct iio_dev *indio_dev = dev_id;
409 struct ad7606_state *st = iio_priv(indio_dev);
411 if (iio_buffer_enabled(indio_dev)) {
412 schedule_work(&st->poll_work);
415 wake_up_interruptible(&st->wq_data_avail);
421 static const struct iio_info ad7606_info_no_os_or_range = {
422 .driver_module = THIS_MODULE,
423 .read_raw = &ad7606_read_raw,
426 static const struct iio_info ad7606_info_os_and_range = {
427 .driver_module = THIS_MODULE,
428 .read_raw = &ad7606_read_raw,
429 .write_raw = &ad7606_write_raw,
430 .attrs = &ad7606_attribute_group_os_and_range,
433 static const struct iio_info ad7606_info_os = {
434 .driver_module = THIS_MODULE,
435 .read_raw = &ad7606_read_raw,
436 .write_raw = &ad7606_write_raw,
437 .attrs = &ad7606_attribute_group_os,
440 static const struct iio_info ad7606_info_range = {
441 .driver_module = THIS_MODULE,
442 .read_raw = &ad7606_read_raw,
443 .attrs = &ad7606_attribute_group_range,
446 struct iio_dev *ad7606_probe(struct device *dev, int irq,
447 void __iomem *base_address,
448 const char *name, unsigned int id,
449 const struct ad7606_bus_ops *bops)
451 struct ad7606_platform_data *pdata = dev->platform_data;
452 struct ad7606_state *st;
454 struct iio_dev *indio_dev;
456 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
458 return ERR_PTR(-ENOMEM);
460 st = iio_priv(indio_dev);
464 st->base_address = base_address;
466 st->oversampling = 1;
468 st->reg = devm_regulator_get(dev, "vcc");
469 if (!IS_ERR(st->reg)) {
470 ret = regulator_enable(st->reg);
476 st->chip_info = &ad7606_chip_info_tbl[id];
478 indio_dev->dev.parent = dev;
479 if (gpio_is_valid(st->pdata->gpio_os0) &&
480 gpio_is_valid(st->pdata->gpio_os1) &&
481 gpio_is_valid(st->pdata->gpio_os2)) {
482 if (gpio_is_valid(st->pdata->gpio_range))
483 indio_dev->info = &ad7606_info_os_and_range;
485 indio_dev->info = &ad7606_info_os;
487 if (gpio_is_valid(st->pdata->gpio_range))
488 indio_dev->info = &ad7606_info_range;
490 indio_dev->info = &ad7606_info_no_os_or_range;
492 indio_dev->modes = INDIO_DIRECT_MODE;
493 indio_dev->name = name;
494 indio_dev->channels = st->chip_info->channels;
495 indio_dev->num_channels = st->chip_info->num_channels;
497 init_waitqueue_head(&st->wq_data_avail);
499 ret = ad7606_request_gpios(st);
501 goto error_disable_reg;
503 ret = ad7606_reset(st);
505 dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
507 ret = request_irq(irq, ad7606_interrupt, IRQF_TRIGGER_FALLING, name,
510 goto error_free_gpios;
512 ret = ad7606_register_ring_funcs_and_init(indio_dev);
516 ret = iio_device_register(indio_dev);
518 goto error_unregister_ring;
521 error_unregister_ring:
522 ad7606_ring_cleanup(indio_dev);
525 free_irq(irq, indio_dev);
528 ad7606_free_gpios(st);
531 if (!IS_ERR(st->reg))
532 regulator_disable(st->reg);
535 EXPORT_SYMBOL_GPL(ad7606_probe);
537 int ad7606_remove(struct iio_dev *indio_dev, int irq)
539 struct ad7606_state *st = iio_priv(indio_dev);
541 iio_device_unregister(indio_dev);
542 ad7606_ring_cleanup(indio_dev);
544 free_irq(irq, indio_dev);
545 if (!IS_ERR(st->reg))
546 regulator_disable(st->reg);
548 ad7606_free_gpios(st);
552 EXPORT_SYMBOL_GPL(ad7606_remove);
554 #ifdef CONFIG_PM_SLEEP
556 static int ad7606_suspend(struct device *dev)
558 struct iio_dev *indio_dev = dev_get_drvdata(dev);
559 struct ad7606_state *st = iio_priv(indio_dev);
561 if (gpio_is_valid(st->pdata->gpio_stby)) {
562 if (gpio_is_valid(st->pdata->gpio_range))
563 gpio_set_value(st->pdata->gpio_range, 1);
564 gpio_set_value(st->pdata->gpio_stby, 0);
570 static int ad7606_resume(struct device *dev)
572 struct iio_dev *indio_dev = dev_get_drvdata(dev);
573 struct ad7606_state *st = iio_priv(indio_dev);
575 if (gpio_is_valid(st->pdata->gpio_stby)) {
576 if (gpio_is_valid(st->pdata->gpio_range))
577 gpio_set_value(st->pdata->gpio_range,
580 gpio_set_value(st->pdata->gpio_stby, 1);
587 SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
588 EXPORT_SYMBOL_GPL(ad7606_pm_ops);
592 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
593 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
594 MODULE_LICENSE("GPL v2");