ACPI: processor idle: Practically limit "Dummy wait" workaround to old Intel systems
[platform/kernel/linux-rpi.git] / drivers / mfd / wm831x-irq.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * wm831x-irq.c  --  Interrupt controller support for Wolfson WM831x PMICs
4  *
5  * Copyright 2009 Wolfson Microelectronics PLC.
6  *
7  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/i2c.h>
13 #include <linux/irq.h>
14 #include <linux/mfd/core.h>
15 #include <linux/interrupt.h>
16 #include <linux/irqdomain.h>
17
18 #include <linux/mfd/wm831x/core.h>
19 #include <linux/mfd/wm831x/pdata.h>
20 #include <linux/mfd/wm831x/gpio.h>
21 #include <linux/mfd/wm831x/irq.h>
22
23 #include <linux/delay.h>
24
25 struct wm831x_irq_data {
26         int primary;
27         int reg;
28         int mask;
29 };
30
31 static struct wm831x_irq_data wm831x_irqs[] = {
32         [WM831X_IRQ_TEMP_THW] = {
33                 .primary = WM831X_TEMP_INT,
34                 .reg = 1,
35                 .mask = WM831X_TEMP_THW_EINT,
36         },
37         [WM831X_IRQ_GPIO_1] = {
38                 .primary = WM831X_GP_INT,
39                 .reg = 5,
40                 .mask = WM831X_GP1_EINT,
41         },
42         [WM831X_IRQ_GPIO_2] = {
43                 .primary = WM831X_GP_INT,
44                 .reg = 5,
45                 .mask = WM831X_GP2_EINT,
46         },
47         [WM831X_IRQ_GPIO_3] = {
48                 .primary = WM831X_GP_INT,
49                 .reg = 5,
50                 .mask = WM831X_GP3_EINT,
51         },
52         [WM831X_IRQ_GPIO_4] = {
53                 .primary = WM831X_GP_INT,
54                 .reg = 5,
55                 .mask = WM831X_GP4_EINT,
56         },
57         [WM831X_IRQ_GPIO_5] = {
58                 .primary = WM831X_GP_INT,
59                 .reg = 5,
60                 .mask = WM831X_GP5_EINT,
61         },
62         [WM831X_IRQ_GPIO_6] = {
63                 .primary = WM831X_GP_INT,
64                 .reg = 5,
65                 .mask = WM831X_GP6_EINT,
66         },
67         [WM831X_IRQ_GPIO_7] = {
68                 .primary = WM831X_GP_INT,
69                 .reg = 5,
70                 .mask = WM831X_GP7_EINT,
71         },
72         [WM831X_IRQ_GPIO_8] = {
73                 .primary = WM831X_GP_INT,
74                 .reg = 5,
75                 .mask = WM831X_GP8_EINT,
76         },
77         [WM831X_IRQ_GPIO_9] = {
78                 .primary = WM831X_GP_INT,
79                 .reg = 5,
80                 .mask = WM831X_GP9_EINT,
81         },
82         [WM831X_IRQ_GPIO_10] = {
83                 .primary = WM831X_GP_INT,
84                 .reg = 5,
85                 .mask = WM831X_GP10_EINT,
86         },
87         [WM831X_IRQ_GPIO_11] = {
88                 .primary = WM831X_GP_INT,
89                 .reg = 5,
90                 .mask = WM831X_GP11_EINT,
91         },
92         [WM831X_IRQ_GPIO_12] = {
93                 .primary = WM831X_GP_INT,
94                 .reg = 5,
95                 .mask = WM831X_GP12_EINT,
96         },
97         [WM831X_IRQ_GPIO_13] = {
98                 .primary = WM831X_GP_INT,
99                 .reg = 5,
100                 .mask = WM831X_GP13_EINT,
101         },
102         [WM831X_IRQ_GPIO_14] = {
103                 .primary = WM831X_GP_INT,
104                 .reg = 5,
105                 .mask = WM831X_GP14_EINT,
106         },
107         [WM831X_IRQ_GPIO_15] = {
108                 .primary = WM831X_GP_INT,
109                 .reg = 5,
110                 .mask = WM831X_GP15_EINT,
111         },
112         [WM831X_IRQ_GPIO_16] = {
113                 .primary = WM831X_GP_INT,
114                 .reg = 5,
115                 .mask = WM831X_GP16_EINT,
116         },
117         [WM831X_IRQ_ON] = {
118                 .primary = WM831X_ON_PIN_INT,
119                 .reg = 1,
120                 .mask = WM831X_ON_PIN_EINT,
121         },
122         [WM831X_IRQ_PPM_SYSLO] = {
123                 .primary = WM831X_PPM_INT,
124                 .reg = 1,
125                 .mask = WM831X_PPM_SYSLO_EINT,
126         },
127         [WM831X_IRQ_PPM_PWR_SRC] = {
128                 .primary = WM831X_PPM_INT,
129                 .reg = 1,
130                 .mask = WM831X_PPM_PWR_SRC_EINT,
131         },
132         [WM831X_IRQ_PPM_USB_CURR] = {
133                 .primary = WM831X_PPM_INT,
134                 .reg = 1,
135                 .mask = WM831X_PPM_USB_CURR_EINT,
136         },
137         [WM831X_IRQ_WDOG_TO] = {
138                 .primary = WM831X_WDOG_INT,
139                 .reg = 1,
140                 .mask = WM831X_WDOG_TO_EINT,
141         },
142         [WM831X_IRQ_RTC_PER] = {
143                 .primary = WM831X_RTC_INT,
144                 .reg = 1,
145                 .mask = WM831X_RTC_PER_EINT,
146         },
147         [WM831X_IRQ_RTC_ALM] = {
148                 .primary = WM831X_RTC_INT,
149                 .reg = 1,
150                 .mask = WM831X_RTC_ALM_EINT,
151         },
152         [WM831X_IRQ_CHG_BATT_HOT] = {
153                 .primary = WM831X_CHG_INT,
154                 .reg = 2,
155                 .mask = WM831X_CHG_BATT_HOT_EINT,
156         },
157         [WM831X_IRQ_CHG_BATT_COLD] = {
158                 .primary = WM831X_CHG_INT,
159                 .reg = 2,
160                 .mask = WM831X_CHG_BATT_COLD_EINT,
161         },
162         [WM831X_IRQ_CHG_BATT_FAIL] = {
163                 .primary = WM831X_CHG_INT,
164                 .reg = 2,
165                 .mask = WM831X_CHG_BATT_FAIL_EINT,
166         },
167         [WM831X_IRQ_CHG_OV] = {
168                 .primary = WM831X_CHG_INT,
169                 .reg = 2,
170                 .mask = WM831X_CHG_OV_EINT,
171         },
172         [WM831X_IRQ_CHG_END] = {
173                 .primary = WM831X_CHG_INT,
174                 .reg = 2,
175                 .mask = WM831X_CHG_END_EINT,
176         },
177         [WM831X_IRQ_CHG_TO] = {
178                 .primary = WM831X_CHG_INT,
179                 .reg = 2,
180                 .mask = WM831X_CHG_TO_EINT,
181         },
182         [WM831X_IRQ_CHG_MODE] = {
183                 .primary = WM831X_CHG_INT,
184                 .reg = 2,
185                 .mask = WM831X_CHG_MODE_EINT,
186         },
187         [WM831X_IRQ_CHG_START] = {
188                 .primary = WM831X_CHG_INT,
189                 .reg = 2,
190                 .mask = WM831X_CHG_START_EINT,
191         },
192         [WM831X_IRQ_TCHDATA] = {
193                 .primary = WM831X_TCHDATA_INT,
194                 .reg = 1,
195                 .mask = WM831X_TCHDATA_EINT,
196         },
197         [WM831X_IRQ_TCHPD] = {
198                 .primary = WM831X_TCHPD_INT,
199                 .reg = 1,
200                 .mask = WM831X_TCHPD_EINT,
201         },
202         [WM831X_IRQ_AUXADC_DATA] = {
203                 .primary = WM831X_AUXADC_INT,
204                 .reg = 1,
205                 .mask = WM831X_AUXADC_DATA_EINT,
206         },
207         [WM831X_IRQ_AUXADC_DCOMP1] = {
208                 .primary = WM831X_AUXADC_INT,
209                 .reg = 1,
210                 .mask = WM831X_AUXADC_DCOMP1_EINT,
211         },
212         [WM831X_IRQ_AUXADC_DCOMP2] = {
213                 .primary = WM831X_AUXADC_INT,
214                 .reg = 1,
215                 .mask = WM831X_AUXADC_DCOMP2_EINT,
216         },
217         [WM831X_IRQ_AUXADC_DCOMP3] = {
218                 .primary = WM831X_AUXADC_INT,
219                 .reg = 1,
220                 .mask = WM831X_AUXADC_DCOMP3_EINT,
221         },
222         [WM831X_IRQ_AUXADC_DCOMP4] = {
223                 .primary = WM831X_AUXADC_INT,
224                 .reg = 1,
225                 .mask = WM831X_AUXADC_DCOMP4_EINT,
226         },
227         [WM831X_IRQ_CS1] = {
228                 .primary = WM831X_CS_INT,
229                 .reg = 2,
230                 .mask = WM831X_CS1_EINT,
231         },
232         [WM831X_IRQ_CS2] = {
233                 .primary = WM831X_CS_INT,
234                 .reg = 2,
235                 .mask = WM831X_CS2_EINT,
236         },
237         [WM831X_IRQ_HC_DC1] = {
238                 .primary = WM831X_HC_INT,
239                 .reg = 4,
240                 .mask = WM831X_HC_DC1_EINT,
241         },
242         [WM831X_IRQ_HC_DC2] = {
243                 .primary = WM831X_HC_INT,
244                 .reg = 4,
245                 .mask = WM831X_HC_DC2_EINT,
246         },
247         [WM831X_IRQ_UV_LDO1] = {
248                 .primary = WM831X_UV_INT,
249                 .reg = 3,
250                 .mask = WM831X_UV_LDO1_EINT,
251         },
252         [WM831X_IRQ_UV_LDO2] = {
253                 .primary = WM831X_UV_INT,
254                 .reg = 3,
255                 .mask = WM831X_UV_LDO2_EINT,
256         },
257         [WM831X_IRQ_UV_LDO3] = {
258                 .primary = WM831X_UV_INT,
259                 .reg = 3,
260                 .mask = WM831X_UV_LDO3_EINT,
261         },
262         [WM831X_IRQ_UV_LDO4] = {
263                 .primary = WM831X_UV_INT,
264                 .reg = 3,
265                 .mask = WM831X_UV_LDO4_EINT,
266         },
267         [WM831X_IRQ_UV_LDO5] = {
268                 .primary = WM831X_UV_INT,
269                 .reg = 3,
270                 .mask = WM831X_UV_LDO5_EINT,
271         },
272         [WM831X_IRQ_UV_LDO6] = {
273                 .primary = WM831X_UV_INT,
274                 .reg = 3,
275                 .mask = WM831X_UV_LDO6_EINT,
276         },
277         [WM831X_IRQ_UV_LDO7] = {
278                 .primary = WM831X_UV_INT,
279                 .reg = 3,
280                 .mask = WM831X_UV_LDO7_EINT,
281         },
282         [WM831X_IRQ_UV_LDO8] = {
283                 .primary = WM831X_UV_INT,
284                 .reg = 3,
285                 .mask = WM831X_UV_LDO8_EINT,
286         },
287         [WM831X_IRQ_UV_LDO9] = {
288                 .primary = WM831X_UV_INT,
289                 .reg = 3,
290                 .mask = WM831X_UV_LDO9_EINT,
291         },
292         [WM831X_IRQ_UV_LDO10] = {
293                 .primary = WM831X_UV_INT,
294                 .reg = 3,
295                 .mask = WM831X_UV_LDO10_EINT,
296         },
297         [WM831X_IRQ_UV_DC1] = {
298                 .primary = WM831X_UV_INT,
299                 .reg = 4,
300                 .mask = WM831X_UV_DC1_EINT,
301         },
302         [WM831X_IRQ_UV_DC2] = {
303                 .primary = WM831X_UV_INT,
304                 .reg = 4,
305                 .mask = WM831X_UV_DC2_EINT,
306         },
307         [WM831X_IRQ_UV_DC3] = {
308                 .primary = WM831X_UV_INT,
309                 .reg = 4,
310                 .mask = WM831X_UV_DC3_EINT,
311         },
312         [WM831X_IRQ_UV_DC4] = {
313                 .primary = WM831X_UV_INT,
314                 .reg = 4,
315                 .mask = WM831X_UV_DC4_EINT,
316         },
317 };
318
319 static inline int irq_data_to_status_reg(struct wm831x_irq_data *irq_data)
320 {
321         return WM831X_INTERRUPT_STATUS_1 - 1 + irq_data->reg;
322 }
323
324 static inline struct wm831x_irq_data *irq_to_wm831x_irq(struct wm831x *wm831x,
325                                                         int irq)
326 {
327         return &wm831x_irqs[irq];
328 }
329
330 static void wm831x_irq_lock(struct irq_data *data)
331 {
332         struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
333
334         mutex_lock(&wm831x->irq_lock);
335 }
336
337 static void wm831x_irq_sync_unlock(struct irq_data *data)
338 {
339         struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
340         int i;
341
342         for (i = 0; i < ARRAY_SIZE(wm831x->gpio_update); i++) {
343                 if (wm831x->gpio_update[i]) {
344                         wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + i,
345                                         WM831X_GPN_INT_MODE | WM831X_GPN_POL,
346                                         wm831x->gpio_update[i]);
347                         wm831x->gpio_update[i] = 0;
348                 }
349         }
350
351         for (i = 0; i < ARRAY_SIZE(wm831x->irq_masks_cur); i++) {
352                 /* If there's been a change in the mask write it back
353                  * to the hardware. */
354                 if (wm831x->irq_masks_cur[i] != wm831x->irq_masks_cache[i]) {
355                         dev_dbg(wm831x->dev, "IRQ mask sync: %x = %x\n",
356                                 WM831X_INTERRUPT_STATUS_1_MASK + i,
357                                 wm831x->irq_masks_cur[i]);
358
359                         wm831x->irq_masks_cache[i] = wm831x->irq_masks_cur[i];
360                         wm831x_reg_write(wm831x,
361                                          WM831X_INTERRUPT_STATUS_1_MASK + i,
362                                          wm831x->irq_masks_cur[i]);
363                 }
364         }
365
366         mutex_unlock(&wm831x->irq_lock);
367 }
368
369 static void wm831x_irq_enable(struct irq_data *data)
370 {
371         struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
372         struct wm831x_irq_data *irq_data = irq_to_wm831x_irq(wm831x,
373                                                              data->hwirq);
374
375         wm831x->irq_masks_cur[irq_data->reg - 1] &= ~irq_data->mask;
376 }
377
378 static void wm831x_irq_disable(struct irq_data *data)
379 {
380         struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
381         struct wm831x_irq_data *irq_data = irq_to_wm831x_irq(wm831x,
382                                                              data->hwirq);
383
384         wm831x->irq_masks_cur[irq_data->reg - 1] |= irq_data->mask;
385 }
386
387 static int wm831x_irq_set_type(struct irq_data *data, unsigned int type)
388 {
389         struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
390         int irq;
391
392         irq = data->hwirq;
393
394         if (irq < WM831X_IRQ_GPIO_1 || irq > WM831X_IRQ_GPIO_11) {
395                 /* Ignore internal-only IRQs */
396                 if (irq >= 0 && irq < WM831X_NUM_IRQS)
397                         return 0;
398                 else
399                         return -EINVAL;
400         }
401
402         /* Rebase the IRQ into the GPIO range so we've got a sensible array
403          * index.
404          */
405         irq -= WM831X_IRQ_GPIO_1;
406
407         /* We set the high bit to flag that we need an update; don't
408          * do the update here as we can be called with the bus lock
409          * held.
410          */
411         wm831x->gpio_level_low[irq] = false;
412         wm831x->gpio_level_high[irq] = false;
413         switch (type) {
414         case IRQ_TYPE_EDGE_BOTH:
415                 wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_INT_MODE;
416                 break;
417         case IRQ_TYPE_EDGE_RISING:
418                 wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_POL;
419                 break;
420         case IRQ_TYPE_EDGE_FALLING:
421                 wm831x->gpio_update[irq] = 0x10000;
422                 break;
423         case IRQ_TYPE_LEVEL_HIGH:
424                 wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_POL;
425                 wm831x->gpio_level_high[irq] = true;
426                 break;
427         case IRQ_TYPE_LEVEL_LOW:
428                 wm831x->gpio_update[irq] = 0x10000;
429                 wm831x->gpio_level_low[irq] = true;
430                 break;
431         default:
432                 return -EINVAL;
433         }
434
435         return 0;
436 }
437
438 static struct irq_chip wm831x_irq_chip = {
439         .name                   = "wm831x",
440         .irq_bus_lock           = wm831x_irq_lock,
441         .irq_bus_sync_unlock    = wm831x_irq_sync_unlock,
442         .irq_disable            = wm831x_irq_disable,
443         .irq_enable             = wm831x_irq_enable,
444         .irq_set_type           = wm831x_irq_set_type,
445 };
446
447 /* The processing of the primary interrupt occurs in a thread so that
448  * we can interact with the device over I2C or SPI. */
449 static irqreturn_t wm831x_irq_thread(int irq, void *data)
450 {
451         struct wm831x *wm831x = data;
452         unsigned int i;
453         int primary, status_addr, ret;
454         int status_regs[WM831X_NUM_IRQ_REGS] = { 0 };
455         int read[WM831X_NUM_IRQ_REGS] = { 0 };
456         int *status;
457
458         primary = wm831x_reg_read(wm831x, WM831X_SYSTEM_INTERRUPTS);
459         if (primary < 0) {
460                 dev_err(wm831x->dev, "Failed to read system interrupt: %d\n",
461                         primary);
462                 goto out;
463         }
464
465         /* The touch interrupts are visible in the primary register as
466          * an optimisation; open code this to avoid complicating the
467          * main handling loop and so we can also skip iterating the
468          * descriptors.
469          */
470         if (primary & WM831X_TCHPD_INT)
471                 handle_nested_irq(irq_find_mapping(wm831x->irq_domain,
472                                                    WM831X_IRQ_TCHPD));
473         if (primary & WM831X_TCHDATA_INT)
474                 handle_nested_irq(irq_find_mapping(wm831x->irq_domain,
475                                                    WM831X_IRQ_TCHDATA));
476         primary &= ~(WM831X_TCHDATA_EINT | WM831X_TCHPD_EINT);
477
478         for (i = 0; i < ARRAY_SIZE(wm831x_irqs); i++) {
479                 int offset = wm831x_irqs[i].reg - 1;
480
481                 if (!(primary & wm831x_irqs[i].primary))
482                         continue;
483
484                 status = &status_regs[offset];
485
486                 /* Hopefully there should only be one register to read
487                  * each time otherwise we ought to do a block read. */
488                 if (!read[offset]) {
489                         status_addr = irq_data_to_status_reg(&wm831x_irqs[i]);
490
491                         *status = wm831x_reg_read(wm831x, status_addr);
492                         if (*status < 0) {
493                                 dev_err(wm831x->dev,
494                                         "Failed to read IRQ status: %d\n",
495                                         *status);
496                                 goto out;
497                         }
498
499                         read[offset] = 1;
500
501                         /* Ignore any bits that we don't think are masked */
502                         *status &= ~wm831x->irq_masks_cur[offset];
503
504                         /* Acknowledge now so we don't miss
505                          * notifications while we handle.
506                          */
507                         wm831x_reg_write(wm831x, status_addr, *status);
508                 }
509
510                 if (*status & wm831x_irqs[i].mask)
511                         handle_nested_irq(irq_find_mapping(wm831x->irq_domain,
512                                                            i));
513
514                 /* Simulate an edge triggered IRQ by polling the input
515                  * status.  This is sucky but improves interoperability.
516                  */
517                 if (primary == WM831X_GP_INT &&
518                     wm831x->gpio_level_high[i - WM831X_IRQ_GPIO_1]) {
519                         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
520                         while (ret & 1 << (i - WM831X_IRQ_GPIO_1)) {
521                                 handle_nested_irq(irq_find_mapping(wm831x->irq_domain,
522                                                                    i));
523                                 ret = wm831x_reg_read(wm831x,
524                                                       WM831X_GPIO_LEVEL);
525                         }
526                 }
527
528                 if (primary == WM831X_GP_INT &&
529                     wm831x->gpio_level_low[i - WM831X_IRQ_GPIO_1]) {
530                         ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
531                         while (!(ret & 1 << (i - WM831X_IRQ_GPIO_1))) {
532                                 handle_nested_irq(irq_find_mapping(wm831x->irq_domain,
533                                                                    i));
534                                 ret = wm831x_reg_read(wm831x,
535                                                       WM831X_GPIO_LEVEL);
536                         }
537                 }
538         }
539
540 out:
541         return IRQ_HANDLED;
542 }
543
544 static int wm831x_irq_map(struct irq_domain *h, unsigned int virq,
545                           irq_hw_number_t hw)
546 {
547         irq_set_chip_data(virq, h->host_data);
548         irq_set_chip_and_handler(virq, &wm831x_irq_chip, handle_edge_irq);
549         irq_set_nested_thread(virq, 1);
550         irq_set_noprobe(virq);
551
552         return 0;
553 }
554
555 static const struct irq_domain_ops wm831x_irq_domain_ops = {
556         .map    = wm831x_irq_map,
557         .xlate  = irq_domain_xlate_twocell,
558 };
559
560 int wm831x_irq_init(struct wm831x *wm831x, int irq)
561 {
562         struct wm831x_pdata *pdata = &wm831x->pdata;
563         struct irq_domain *domain;
564         int i, ret, irq_base;
565
566         mutex_init(&wm831x->irq_lock);
567
568         /* Mask the individual interrupt sources */
569         for (i = 0; i < ARRAY_SIZE(wm831x->irq_masks_cur); i++) {
570                 wm831x->irq_masks_cur[i] = 0xffff;
571                 wm831x->irq_masks_cache[i] = 0xffff;
572                 wm831x_reg_write(wm831x, WM831X_INTERRUPT_STATUS_1_MASK + i,
573                                  0xffff);
574         }
575
576         /* Try to dynamically allocate IRQs if no base is specified */
577         if (pdata->irq_base) {
578                 irq_base = irq_alloc_descs(pdata->irq_base, 0,
579                                            WM831X_NUM_IRQS, 0);
580                 if (irq_base < 0) {
581                         dev_warn(wm831x->dev, "Failed to allocate IRQs: %d\n",
582                                  irq_base);
583                         irq_base = 0;
584                 }
585         } else {
586                 irq_base = 0;
587         }
588
589         if (irq_base)
590                 domain = irq_domain_add_legacy(wm831x->dev->of_node,
591                                                ARRAY_SIZE(wm831x_irqs),
592                                                irq_base, 0,
593                                                &wm831x_irq_domain_ops,
594                                                wm831x);
595         else
596                 domain = irq_domain_add_linear(wm831x->dev->of_node,
597                                                ARRAY_SIZE(wm831x_irqs),
598                                                &wm831x_irq_domain_ops,
599                                                wm831x);
600
601         if (!domain) {
602                 dev_warn(wm831x->dev, "Failed to allocate IRQ domain\n");
603                 return -EINVAL;
604         }
605
606         if (pdata->irq_cmos)
607                 i = 0;
608         else
609                 i = WM831X_IRQ_OD;
610
611         wm831x_set_bits(wm831x, WM831X_IRQ_CONFIG,
612                         WM831X_IRQ_OD, i);
613
614         wm831x->irq = irq;
615         wm831x->irq_domain = domain;
616
617         if (irq) {
618                 /* Try to flag /IRQ as a wake source; there are a number of
619                  * unconditional wake sources in the PMIC so this isn't
620                  * conditional but we don't actually care *too* much if it
621                  * fails.
622                  */
623                 ret = enable_irq_wake(irq);
624                 if (ret != 0) {
625                         dev_warn(wm831x->dev,
626                                  "Can't enable IRQ as wake source: %d\n",
627                                  ret);
628                 }
629
630                 ret = request_threaded_irq(irq, NULL, wm831x_irq_thread,
631                                            IRQF_TRIGGER_LOW | IRQF_ONESHOT,
632                                            "wm831x", wm831x);
633                 if (ret != 0) {
634                         dev_err(wm831x->dev, "Failed to request IRQ %d: %d\n",
635                                 irq, ret);
636                         return ret;
637                 }
638         } else {
639                 dev_warn(wm831x->dev,
640                          "No interrupt specified - functionality limited\n");
641         }
642
643         /* Enable top level interrupts, we mask at secondary level */
644         wm831x_reg_write(wm831x, WM831X_SYSTEM_INTERRUPTS_MASK, 0);
645
646         return 0;
647 }
648
649 void wm831x_irq_exit(struct wm831x *wm831x)
650 {
651         if (wm831x->irq)
652                 free_irq(wm831x->irq, wm831x);
653 }