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1/*
2 * Driver for the ADC present in the Atmel AT91 evaluation boards.
3 *
4 * Copyright 2011 Free Electrons
5 *
6 * Licensed under the GPLv2 or later.
7 */
8
9#include <linux/bitmap.h>
10#include <linux/bitops.h>
11#include <linux/clk.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/interrupt.h>
15#include <linux/jiffies.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/of.h>
19#include <linux/of_device.h>
20#include <linux/platform_device.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/wait.h>
24
25#include <linux/platform_data/at91_adc.h>
26
27#include <linux/iio/iio.h>
28#include <linux/iio/buffer.h>
29#include <linux/iio/kfifo_buf.h>
30#include <linux/iio/trigger.h>
31#include <linux/iio/trigger_consumer.h>
32
33#include <mach/at91_adc.h>
34
35#define AT91_ADC_CHAN(st, ch) \
36 (st->registers->channel_base + (ch * 4))
37#define at91_adc_readl(st, reg) \
38 (readl_relaxed(st->reg_base + reg))
39#define at91_adc_writel(st, reg, val) \
40 (writel_relaxed(val, st->reg_base + reg))
41
42struct at91_adc_state {
43 struct clk *adc_clk;
44 u16 *buffer;
45 unsigned long channels_mask;
46 struct clk *clk;
47 bool done;
48 int irq;
49 bool irq_enabled;
50 u16 last_value;
51 struct mutex lock;
52 u8 num_channels;
53 void __iomem *reg_base;
54 struct at91_adc_reg_desc *registers;
55 u8 startup_time;
56 struct iio_trigger **trig;
57 struct at91_adc_trigger *trigger_list;
58 u32 trigger_number;
59 bool use_external;
60 u32 vref_mv;
61 wait_queue_head_t wq_data_avail;
62};
63
64static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
65{
66 struct iio_poll_func *pf = p;
67 struct iio_dev *idev = pf->indio_dev;
68 struct at91_adc_state *st = iio_priv(idev);
69 struct iio_buffer *buffer = idev->buffer;
70 int i, j = 0;
71
72 for (i = 0; i < idev->masklength; i++) {
73 if (!test_bit(i, idev->active_scan_mask))
74 continue;
75 st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
76 j++;
77 }
78
79 if (idev->scan_timestamp) {
80 s64 *timestamp = (s64 *)((u8 *)st->buffer +
81 ALIGN(j, sizeof(s64)));
82 *timestamp = pf->timestamp;
83 }
84
85 buffer->access->store_to(buffer, (u8 *)st->buffer, pf->timestamp);
86
87 iio_trigger_notify_done(idev->trig);
88 st->irq_enabled = true;
89
90 /* Needed to ACK the DRDY interruption */
91 at91_adc_readl(st, AT91_ADC_LCDR);
92
93 enable_irq(st->irq);
94
95 return IRQ_HANDLED;
96}
97
98static irqreturn_t at91_adc_eoc_trigger(int irq, void *private)
99{
100 struct iio_dev *idev = private;
101 struct at91_adc_state *st = iio_priv(idev);
102 u32 status = at91_adc_readl(st, st->registers->status_register);
103
104 if (!(status & st->registers->drdy_mask))
105 return IRQ_HANDLED;
106
107 if (iio_buffer_enabled(idev)) {
108 disable_irq_nosync(irq);
109 st->irq_enabled = false;
110 iio_trigger_poll(idev->trig, iio_get_time_ns());
111 } else {
112 st->last_value = at91_adc_readl(st, AT91_ADC_LCDR);
113 st->done = true;
114 wake_up_interruptible(&st->wq_data_avail);
115 }
116
117 return IRQ_HANDLED;
118}
119
120static int at91_adc_channel_init(struct iio_dev *idev)
121{
122 struct at91_adc_state *st = iio_priv(idev);
123 struct iio_chan_spec *chan_array, *timestamp;
124 int bit, idx = 0;
125
126 idev->num_channels = bitmap_weight(&st->channels_mask,
127 st->num_channels) + 1;
128
129 chan_array = devm_kzalloc(&idev->dev,
130 ((idev->num_channels + 1) *
131 sizeof(struct iio_chan_spec)),
132 GFP_KERNEL);
133
134 if (!chan_array)
135 return -ENOMEM;
136
137 for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
138 struct iio_chan_spec *chan = chan_array + idx;
139
140 chan->type = IIO_VOLTAGE;
141 chan->indexed = 1;
142 chan->channel = bit;
143 chan->scan_index = idx;
144 chan->scan_type.sign = 'u';
145 chan->scan_type.realbits = 10;
146 chan->scan_type.storagebits = 16;
147 chan->info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT |
148 IIO_CHAN_INFO_RAW_SEPARATE_BIT;
149 idx++;
150 }
151 timestamp = chan_array + idx;
152
153 timestamp->type = IIO_TIMESTAMP;
154 timestamp->channel = -1;
155 timestamp->scan_index = idx;
156 timestamp->scan_type.sign = 's';
157 timestamp->scan_type.realbits = 64;
158 timestamp->scan_type.storagebits = 64;
159
160 idev->channels = chan_array;
161 return idev->num_channels;
162}
163
164static u8 at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
165 struct at91_adc_trigger *triggers,
166 const char *trigger_name)
167{
168 struct at91_adc_state *st = iio_priv(idev);
169 u8 value = 0;
170 int i;
171
172 for (i = 0; i < st->trigger_number; i++) {
173 char *name = kasprintf(GFP_KERNEL,
174 "%s-dev%d-%s",
175 idev->name,
176 idev->id,
177 triggers[i].name);
178 if (!name)
179 return -ENOMEM;
180
181 if (strcmp(trigger_name, name) == 0) {
182 value = triggers[i].value;
183 kfree(name);
184 break;
185 }
186
187 kfree(name);
188 }
189
190 return value;
191}
192
193static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
194{
195 struct iio_dev *idev = trig->private_data;
196 struct at91_adc_state *st = iio_priv(idev);
197 struct iio_buffer *buffer = idev->buffer;
198 struct at91_adc_reg_desc *reg = st->registers;
199 u32 status = at91_adc_readl(st, reg->trigger_register);
200 u8 value;
201 u8 bit;
202
203 value = at91_adc_get_trigger_value_by_name(idev,
204 st->trigger_list,
205 idev->trig->name);
206 if (value == 0)
207 return -EINVAL;
208
209 if (state) {
210 st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
211 if (st->buffer == NULL)
212 return -ENOMEM;
213
214 at91_adc_writel(st, reg->trigger_register,
215 status | value);
216
217 for_each_set_bit(bit, buffer->scan_mask,
218 st->num_channels) {
219 struct iio_chan_spec const *chan = idev->channels + bit;
220 at91_adc_writel(st, AT91_ADC_CHER,
221 AT91_ADC_CH(chan->channel));
222 }
223
224 at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
225
226 } else {
227 at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
228
229 at91_adc_writel(st, reg->trigger_register,
230 status & ~value);
231
232 for_each_set_bit(bit, buffer->scan_mask,
233 st->num_channels) {
234 struct iio_chan_spec const *chan = idev->channels + bit;
235 at91_adc_writel(st, AT91_ADC_CHDR,
236 AT91_ADC_CH(chan->channel));
237 }
238 kfree(st->buffer);
239 }
240
241 return 0;
242}
243
244static const struct iio_trigger_ops at91_adc_trigger_ops = {
245 .owner = THIS_MODULE,
246 .set_trigger_state = &at91_adc_configure_trigger,
247};
248
249static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
250 struct at91_adc_trigger *trigger)
251{
252 struct iio_trigger *trig;
253 int ret;
254
255 trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
256 idev->id, trigger->name);
257 if (trig == NULL)
258 return NULL;
259
260 trig->dev.parent = idev->dev.parent;
261 trig->private_data = idev;
262 trig->ops = &at91_adc_trigger_ops;
263
264 ret = iio_trigger_register(trig);
265 if (ret)
266 return NULL;
267
268 return trig;
269}
270
271static int at91_adc_trigger_init(struct iio_dev *idev)
272{
273 struct at91_adc_state *st = iio_priv(idev);
274 int i, ret;
275
276 st->trig = devm_kzalloc(&idev->dev,
277 st->trigger_number * sizeof(st->trig),
278 GFP_KERNEL);
279
280 if (st->trig == NULL) {
281 ret = -ENOMEM;
282 goto error_ret;
283 }
284
285 for (i = 0; i < st->trigger_number; i++) {
286 if (st->trigger_list[i].is_external && !(st->use_external))
287 continue;
288
289 st->trig[i] = at91_adc_allocate_trigger(idev,
290 st->trigger_list + i);
291 if (st->trig[i] == NULL) {
292 dev_err(&idev->dev,
293 "Could not allocate trigger %d\n", i);
294 ret = -ENOMEM;
295 goto error_trigger;
296 }
297 }
298
299 return 0;
300
301error_trigger:
302 for (i--; i >= 0; i--) {
303 iio_trigger_unregister(st->trig[i]);
304 iio_trigger_free(st->trig[i]);
305 }
306error_ret:
307 return ret;
308}
309
310static void at91_adc_trigger_remove(struct iio_dev *idev)
311{
312 struct at91_adc_state *st = iio_priv(idev);
313 int i;
314
315 for (i = 0; i < st->trigger_number; i++) {
316 iio_trigger_unregister(st->trig[i]);
317 iio_trigger_free(st->trig[i]);
318 }
319}
320
321static const struct iio_buffer_setup_ops at91_adc_buffer_ops = {
322 .preenable = &iio_sw_buffer_preenable,
323 .postenable = &iio_triggered_buffer_postenable,
324 .predisable = &iio_triggered_buffer_predisable,
325};
326
327static int at91_adc_buffer_init(struct iio_dev *idev)
328{
329 int ret;
330
331 idev->buffer = iio_kfifo_allocate(idev);
332 if (!idev->buffer) {
333 ret = -ENOMEM;
334 goto error_ret;
335 }
336
337 idev->pollfunc = iio_alloc_pollfunc(&iio_pollfunc_store_time,
338 &at91_adc_trigger_handler,
339 IRQF_ONESHOT,
340 idev,
341 "%s-consumer%d",
342 idev->name,
343 idev->id);
344 if (idev->pollfunc == NULL) {
345 ret = -ENOMEM;
346 goto error_pollfunc;
347 }
348
349 idev->setup_ops = &at91_adc_buffer_ops;
350 idev->modes |= INDIO_BUFFER_TRIGGERED;
351
352 ret = iio_buffer_register(idev,
353 idev->channels,
354 idev->num_channels);
355 if (ret)
356 goto error_register;
357
358 return 0;
359
360error_register:
361 iio_dealloc_pollfunc(idev->pollfunc);
362error_pollfunc:
363 iio_kfifo_free(idev->buffer);
364error_ret:
365 return ret;
366}
367
368static void at91_adc_buffer_remove(struct iio_dev *idev)
369{
370 iio_buffer_unregister(idev);
371 iio_dealloc_pollfunc(idev->pollfunc);
372 iio_kfifo_free(idev->buffer);
373}
374
375static int at91_adc_read_raw(struct iio_dev *idev,
376 struct iio_chan_spec const *chan,
377 int *val, int *val2, long mask)
378{
379 struct at91_adc_state *st = iio_priv(idev);
380 int ret;
381
382 switch (mask) {
383 case IIO_CHAN_INFO_RAW:
384 mutex_lock(&st->lock);
385
386 at91_adc_writel(st, AT91_ADC_CHER,
387 AT91_ADC_CH(chan->channel));
388 at91_adc_writel(st, AT91_ADC_IER, st->registers->drdy_mask);
389 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
390
391 ret = wait_event_interruptible_timeout(st->wq_data_avail,
392 st->done,
393 msecs_to_jiffies(1000));
394 if (ret == 0)
395 return -ETIMEDOUT;
396 else if (ret < 0)
397 return ret;
398
399 *val = st->last_value;
400
401 at91_adc_writel(st, AT91_ADC_CHDR,
402 AT91_ADC_CH(chan->channel));
403 at91_adc_writel(st, AT91_ADC_IDR, st->registers->drdy_mask);
404
405 st->last_value = 0;
406 st->done = false;
407 mutex_unlock(&st->lock);
408 return IIO_VAL_INT;
409
410 case IIO_CHAN_INFO_SCALE:
411 *val = (st->vref_mv * 1000) >> chan->scan_type.realbits;
412 *val2 = 0;
413 return IIO_VAL_INT_PLUS_MICRO;
414 default:
415 break;
416 }
417 return -EINVAL;
418}
419
420static int at91_adc_probe_dt(struct at91_adc_state *st,
421 struct platform_device *pdev)
422{
423 struct iio_dev *idev = iio_priv_to_dev(st);
424 struct device_node *node = pdev->dev.of_node;
425 struct device_node *trig_node;
426 int i = 0, ret;
427 u32 prop;
428
429 if (!node)
430 return -EINVAL;
431
432 st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
433
434 if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
435 dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
436 ret = -EINVAL;
437 goto error_ret;
438 }
439 st->channels_mask = prop;
440
441 if (of_property_read_u32(node, "atmel,adc-num-channels", &prop)) {
442 dev_err(&idev->dev, "Missing adc-num-channels property in the DT.\n");
443 ret = -EINVAL;
444 goto error_ret;
445 }
446 st->num_channels = prop;
447
448 if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
449 dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
450 ret = -EINVAL;
451 goto error_ret;
452 }
453 st->startup_time = prop;
454
455
456 if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
457 dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
458 ret = -EINVAL;
459 goto error_ret;
460 }
461 st->vref_mv = prop;
462
463 st->registers = devm_kzalloc(&idev->dev,
464 sizeof(struct at91_adc_reg_desc),
465 GFP_KERNEL);
466 if (!st->registers) {
467 dev_err(&idev->dev, "Could not allocate register memory.\n");
468 ret = -ENOMEM;
469 goto error_ret;
470 }
471
472 if (of_property_read_u32(node, "atmel,adc-channel-base", &prop)) {
473 dev_err(&idev->dev, "Missing adc-channel-base property in the DT.\n");
474 ret = -EINVAL;
475 goto error_ret;
476 }
477 st->registers->channel_base = prop;
478
479 if (of_property_read_u32(node, "atmel,adc-drdy-mask", &prop)) {
480 dev_err(&idev->dev, "Missing adc-drdy-mask property in the DT.\n");
481 ret = -EINVAL;
482 goto error_ret;
483 }
484 st->registers->drdy_mask = prop;
485
486 if (of_property_read_u32(node, "atmel,adc-status-register", &prop)) {
487 dev_err(&idev->dev, "Missing adc-status-register property in the DT.\n");
488 ret = -EINVAL;
489 goto error_ret;
490 }
491 st->registers->status_register = prop;
492
493 if (of_property_read_u32(node, "atmel,adc-trigger-register", &prop)) {
494 dev_err(&idev->dev, "Missing adc-trigger-register property in the DT.\n");
495 ret = -EINVAL;
496 goto error_ret;
497 }
498 st->registers->trigger_register = prop;
499
500 st->trigger_number = of_get_child_count(node);
501 st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
502 sizeof(struct at91_adc_trigger),
503 GFP_KERNEL);
504 if (!st->trigger_list) {
505 dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
506 ret = -ENOMEM;
507 goto error_ret;
508 }
509
510 for_each_child_of_node(node, trig_node) {
511 struct at91_adc_trigger *trig = st->trigger_list + i;
512 const char *name;
513
514 if (of_property_read_string(trig_node, "trigger-name", &name)) {
515 dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
516 ret = -EINVAL;
517 goto error_ret;
518 }
519 trig->name = name;
520
521 if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
522 dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
523 ret = -EINVAL;
524 goto error_ret;
525 }
526 trig->value = prop;
527 trig->is_external = of_property_read_bool(trig_node, "trigger-external");
528 i++;
529 }
530
531 return 0;
532
533error_ret:
534 return ret;
535}
536
537static int at91_adc_probe_pdata(struct at91_adc_state *st,
538 struct platform_device *pdev)
539{
540 struct at91_adc_data *pdata = pdev->dev.platform_data;
541
542 if (!pdata)
543 return -EINVAL;
544
545 st->use_external = pdata->use_external_triggers;
546 st->vref_mv = pdata->vref;
547 st->channels_mask = pdata->channels_used;
548 st->num_channels = pdata->num_channels;
549 st->startup_time = pdata->startup_time;
550 st->trigger_number = pdata->trigger_number;
551 st->trigger_list = pdata->trigger_list;
552 st->registers = pdata->registers;
553
554 return 0;
555}
556
557static const struct iio_info at91_adc_info = {
558 .driver_module = THIS_MODULE,
559 .read_raw = &at91_adc_read_raw,
560};
561
562static int __devinit at91_adc_probe(struct platform_device *pdev)
563{
564 unsigned int prsc, mstrclk, ticks, adc_clk;
565 int ret;
566 struct iio_dev *idev;
567 struct at91_adc_state *st;
568 struct resource *res;
569
570 idev = iio_device_alloc(sizeof(struct at91_adc_state));
571 if (idev == NULL) {
572 ret = -ENOMEM;
573 goto error_ret;
574 }
575
576 st = iio_priv(idev);
577
578 if (pdev->dev.of_node)
579 ret = at91_adc_probe_dt(st, pdev);
580 else
581 ret = at91_adc_probe_pdata(st, pdev);
582
583 if (ret) {
584 dev_err(&pdev->dev, "No platform data available.\n");
585 ret = -EINVAL;
586 goto error_free_device;
587 }
588
589 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
590 if (!res) {
591 dev_err(&pdev->dev, "No resource defined\n");
592 ret = -ENXIO;
593 goto error_ret;
594 }
595
596 platform_set_drvdata(pdev, idev);
597
598 idev->dev.parent = &pdev->dev;
599 idev->name = dev_name(&pdev->dev);
600 idev->modes = INDIO_DIRECT_MODE;
601 idev->info = &at91_adc_info;
602
603 st->irq = platform_get_irq(pdev, 0);
604 if (st->irq < 0) {
605 dev_err(&pdev->dev, "No IRQ ID is designated\n");
606 ret = -ENODEV;
607 goto error_free_device;
608 }
609
610 if (!request_mem_region(res->start, resource_size(res),
611 "AT91 adc registers")) {
612 dev_err(&pdev->dev, "Resources are unavailable.\n");
613 ret = -EBUSY;
614 goto error_free_device;
615 }
616
617 st->reg_base = ioremap(res->start, resource_size(res));
618 if (!st->reg_base) {
619 dev_err(&pdev->dev, "Failed to map registers.\n");
620 ret = -ENOMEM;
621 goto error_release_mem;
622 }
623
624 /*
625 * Disable all IRQs before setting up the handler
626 */
627 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
628 at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
629 ret = request_irq(st->irq,
630 at91_adc_eoc_trigger,
631 0,
632 pdev->dev.driver->name,
633 idev);
634 if (ret) {
635 dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
636 goto error_unmap_reg;
637 }
638
639 st->clk = clk_get(&pdev->dev, "adc_clk");
640 if (IS_ERR(st->clk)) {
641 dev_err(&pdev->dev, "Failed to get the clock.\n");
642 ret = PTR_ERR(st->clk);
643 goto error_free_irq;
644 }
645
646 ret = clk_prepare(st->clk);
647 if (ret) {
648 dev_err(&pdev->dev, "Could not prepare the clock.\n");
649 goto error_free_clk;
650 }
651
652 ret = clk_enable(st->clk);
653 if (ret) {
654 dev_err(&pdev->dev, "Could not enable the clock.\n");
655 goto error_unprepare_clk;
656 }
657
658 st->adc_clk = clk_get(&pdev->dev, "adc_op_clk");
659 if (IS_ERR(st->adc_clk)) {
660 dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
661 ret = PTR_ERR(st->clk);
662 goto error_disable_clk;
663 }
664
665 ret = clk_prepare(st->adc_clk);
666 if (ret) {
667 dev_err(&pdev->dev, "Could not prepare the ADC clock.\n");
668 goto error_free_adc_clk;
669 }
670
671 ret = clk_enable(st->adc_clk);
672 if (ret) {
673 dev_err(&pdev->dev, "Could not enable the ADC clock.\n");
674 goto error_unprepare_adc_clk;
675 }
676
677 /*
678 * Prescaler rate computation using the formula from the Atmel's
679 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
680 * specified by the electrical characteristics of the board.
681 */
682 mstrclk = clk_get_rate(st->clk);
683 adc_clk = clk_get_rate(st->adc_clk);
684 prsc = (mstrclk / (2 * adc_clk)) - 1;
685
686 if (!st->startup_time) {
687 dev_err(&pdev->dev, "No startup time available.\n");
688 ret = -EINVAL;
689 goto error_disable_adc_clk;
690 }
691
692 /*
693 * Number of ticks needed to cover the startup time of the ADC as
694 * defined in the electrical characteristics of the board, divided by 8.
695 * The formula thus is : Startup Time = (ticks + 1) * 8 / ADC Clock
696 */
697 ticks = round_up((st->startup_time * adc_clk /
698 1000000) - 1, 8) / 8;
699 at91_adc_writel(st, AT91_ADC_MR,
700 (AT91_ADC_PRESCAL_(prsc) & AT91_ADC_PRESCAL) |
701 (AT91_ADC_STARTUP_(ticks) & AT91_ADC_STARTUP));
702
703 /* Setup the ADC channels available on the board */
704 ret = at91_adc_channel_init(idev);
705 if (ret < 0) {
706 dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
707 goto error_disable_adc_clk;
708 }
709
710 init_waitqueue_head(&st->wq_data_avail);
711 mutex_init(&st->lock);
712
713 ret = at91_adc_buffer_init(idev);
714 if (ret < 0) {
715 dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
716 goto error_disable_adc_clk;
717 }
718
719 ret = at91_adc_trigger_init(idev);
720 if (ret < 0) {
721 dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
722 goto error_unregister_buffer;
723 }
724
725 ret = iio_device_register(idev);
726 if (ret < 0) {
727 dev_err(&pdev->dev, "Couldn't register the device.\n");
728 goto error_remove_triggers;
729 }
730
731 return 0;
732
733error_remove_triggers:
734 at91_adc_trigger_remove(idev);
735error_unregister_buffer:
736 at91_adc_buffer_remove(idev);
737error_disable_adc_clk:
738 clk_disable(st->adc_clk);
739error_unprepare_adc_clk:
740 clk_unprepare(st->adc_clk);
741error_free_adc_clk:
742 clk_put(st->adc_clk);
743error_disable_clk:
744 clk_disable(st->clk);
745error_unprepare_clk:
746 clk_unprepare(st->clk);
747error_free_clk:
748 clk_put(st->clk);
749error_free_irq:
750 free_irq(st->irq, idev);
751error_unmap_reg:
752 iounmap(st->reg_base);
753error_release_mem:
754 release_mem_region(res->start, resource_size(res));
755error_free_device:
756 iio_device_free(idev);
757error_ret:
758 return ret;
759}
760
761static int __devexit at91_adc_remove(struct platform_device *pdev)
762{
763 struct iio_dev *idev = platform_get_drvdata(pdev);
764 struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
765 struct at91_adc_state *st = iio_priv(idev);
766
767 iio_device_unregister(idev);
768 at91_adc_trigger_remove(idev);
769 at91_adc_buffer_remove(idev);
770 clk_disable_unprepare(st->adc_clk);
771 clk_put(st->adc_clk);
772 clk_disable(st->clk);
773 clk_unprepare(st->clk);
774 clk_put(st->clk);
775 free_irq(st->irq, idev);
776 iounmap(st->reg_base);
777 release_mem_region(res->start, resource_size(res));
778 iio_device_free(idev);
779
780 return 0;
781}
782
783static const struct of_device_id at91_adc_dt_ids[] = {
784 { .compatible = "atmel,at91sam9260-adc" },
785 {},
786};
787MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
788
789static struct platform_driver at91_adc_driver = {
790 .probe = at91_adc_probe,
791 .remove = __devexit_p(at91_adc_remove),
792 .driver = {
793 .name = "at91_adc",
794 .of_match_table = of_match_ptr(at91_adc_dt_ids),
795 },
796};
797
798module_platform_driver(at91_adc_driver);
799
800MODULE_LICENSE("GPL");
801MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
802MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");