xref: /openbmc/linux/drivers/mfd/wm831x-irq.c (revision 251f39fe42dae863bd24e30864e6b66076ba076d)
1 /*
2  * wm831x-irq.c  --  Interrupt controller support for Wolfson WM831x PMICs
3  *
4  * Copyright 2009 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/i2c.h>
18 #include <linux/irq.h>
19 #include <linux/mfd/core.h>
20 #include <linux/interrupt.h>
21 
22 #include <linux/mfd/wm831x/core.h>
23 #include <linux/mfd/wm831x/pdata.h>
24 #include <linux/mfd/wm831x/gpio.h>
25 #include <linux/mfd/wm831x/irq.h>
26 
27 #include <linux/delay.h>
28 
29 struct wm831x_irq_data {
30 	int primary;
31 	int reg;
32 	int mask;
33 };
34 
35 static struct wm831x_irq_data wm831x_irqs[] = {
36 	[WM831X_IRQ_TEMP_THW] = {
37 		.primary = WM831X_TEMP_INT,
38 		.reg = 1,
39 		.mask = WM831X_TEMP_THW_EINT,
40 	},
41 	[WM831X_IRQ_GPIO_1] = {
42 		.primary = WM831X_GP_INT,
43 		.reg = 5,
44 		.mask = WM831X_GP1_EINT,
45 	},
46 	[WM831X_IRQ_GPIO_2] = {
47 		.primary = WM831X_GP_INT,
48 		.reg = 5,
49 		.mask = WM831X_GP2_EINT,
50 	},
51 	[WM831X_IRQ_GPIO_3] = {
52 		.primary = WM831X_GP_INT,
53 		.reg = 5,
54 		.mask = WM831X_GP3_EINT,
55 	},
56 	[WM831X_IRQ_GPIO_4] = {
57 		.primary = WM831X_GP_INT,
58 		.reg = 5,
59 		.mask = WM831X_GP4_EINT,
60 	},
61 	[WM831X_IRQ_GPIO_5] = {
62 		.primary = WM831X_GP_INT,
63 		.reg = 5,
64 		.mask = WM831X_GP5_EINT,
65 	},
66 	[WM831X_IRQ_GPIO_6] = {
67 		.primary = WM831X_GP_INT,
68 		.reg = 5,
69 		.mask = WM831X_GP6_EINT,
70 	},
71 	[WM831X_IRQ_GPIO_7] = {
72 		.primary = WM831X_GP_INT,
73 		.reg = 5,
74 		.mask = WM831X_GP7_EINT,
75 	},
76 	[WM831X_IRQ_GPIO_8] = {
77 		.primary = WM831X_GP_INT,
78 		.reg = 5,
79 		.mask = WM831X_GP8_EINT,
80 	},
81 	[WM831X_IRQ_GPIO_9] = {
82 		.primary = WM831X_GP_INT,
83 		.reg = 5,
84 		.mask = WM831X_GP9_EINT,
85 	},
86 	[WM831X_IRQ_GPIO_10] = {
87 		.primary = WM831X_GP_INT,
88 		.reg = 5,
89 		.mask = WM831X_GP10_EINT,
90 	},
91 	[WM831X_IRQ_GPIO_11] = {
92 		.primary = WM831X_GP_INT,
93 		.reg = 5,
94 		.mask = WM831X_GP11_EINT,
95 	},
96 	[WM831X_IRQ_GPIO_12] = {
97 		.primary = WM831X_GP_INT,
98 		.reg = 5,
99 		.mask = WM831X_GP12_EINT,
100 	},
101 	[WM831X_IRQ_GPIO_13] = {
102 		.primary = WM831X_GP_INT,
103 		.reg = 5,
104 		.mask = WM831X_GP13_EINT,
105 	},
106 	[WM831X_IRQ_GPIO_14] = {
107 		.primary = WM831X_GP_INT,
108 		.reg = 5,
109 		.mask = WM831X_GP14_EINT,
110 	},
111 	[WM831X_IRQ_GPIO_15] = {
112 		.primary = WM831X_GP_INT,
113 		.reg = 5,
114 		.mask = WM831X_GP15_EINT,
115 	},
116 	[WM831X_IRQ_GPIO_16] = {
117 		.primary = WM831X_GP_INT,
118 		.reg = 5,
119 		.mask = WM831X_GP16_EINT,
120 	},
121 	[WM831X_IRQ_ON] = {
122 		.primary = WM831X_ON_PIN_INT,
123 		.reg = 1,
124 		.mask = WM831X_ON_PIN_EINT,
125 	},
126 	[WM831X_IRQ_PPM_SYSLO] = {
127 		.primary = WM831X_PPM_INT,
128 		.reg = 1,
129 		.mask = WM831X_PPM_SYSLO_EINT,
130 	},
131 	[WM831X_IRQ_PPM_PWR_SRC] = {
132 		.primary = WM831X_PPM_INT,
133 		.reg = 1,
134 		.mask = WM831X_PPM_PWR_SRC_EINT,
135 	},
136 	[WM831X_IRQ_PPM_USB_CURR] = {
137 		.primary = WM831X_PPM_INT,
138 		.reg = 1,
139 		.mask = WM831X_PPM_USB_CURR_EINT,
140 	},
141 	[WM831X_IRQ_WDOG_TO] = {
142 		.primary = WM831X_WDOG_INT,
143 		.reg = 1,
144 		.mask = WM831X_WDOG_TO_EINT,
145 	},
146 	[WM831X_IRQ_RTC_PER] = {
147 		.primary = WM831X_RTC_INT,
148 		.reg = 1,
149 		.mask = WM831X_RTC_PER_EINT,
150 	},
151 	[WM831X_IRQ_RTC_ALM] = {
152 		.primary = WM831X_RTC_INT,
153 		.reg = 1,
154 		.mask = WM831X_RTC_ALM_EINT,
155 	},
156 	[WM831X_IRQ_CHG_BATT_HOT] = {
157 		.primary = WM831X_CHG_INT,
158 		.reg = 2,
159 		.mask = WM831X_CHG_BATT_HOT_EINT,
160 	},
161 	[WM831X_IRQ_CHG_BATT_COLD] = {
162 		.primary = WM831X_CHG_INT,
163 		.reg = 2,
164 		.mask = WM831X_CHG_BATT_COLD_EINT,
165 	},
166 	[WM831X_IRQ_CHG_BATT_FAIL] = {
167 		.primary = WM831X_CHG_INT,
168 		.reg = 2,
169 		.mask = WM831X_CHG_BATT_FAIL_EINT,
170 	},
171 	[WM831X_IRQ_CHG_OV] = {
172 		.primary = WM831X_CHG_INT,
173 		.reg = 2,
174 		.mask = WM831X_CHG_OV_EINT,
175 	},
176 	[WM831X_IRQ_CHG_END] = {
177 		.primary = WM831X_CHG_INT,
178 		.reg = 2,
179 		.mask = WM831X_CHG_END_EINT,
180 	},
181 	[WM831X_IRQ_CHG_TO] = {
182 		.primary = WM831X_CHG_INT,
183 		.reg = 2,
184 		.mask = WM831X_CHG_TO_EINT,
185 	},
186 	[WM831X_IRQ_CHG_MODE] = {
187 		.primary = WM831X_CHG_INT,
188 		.reg = 2,
189 		.mask = WM831X_CHG_MODE_EINT,
190 	},
191 	[WM831X_IRQ_CHG_START] = {
192 		.primary = WM831X_CHG_INT,
193 		.reg = 2,
194 		.mask = WM831X_CHG_START_EINT,
195 	},
196 	[WM831X_IRQ_TCHDATA] = {
197 		.primary = WM831X_TCHDATA_INT,
198 		.reg = 1,
199 		.mask = WM831X_TCHDATA_EINT,
200 	},
201 	[WM831X_IRQ_TCHPD] = {
202 		.primary = WM831X_TCHPD_INT,
203 		.reg = 1,
204 		.mask = WM831X_TCHPD_EINT,
205 	},
206 	[WM831X_IRQ_AUXADC_DATA] = {
207 		.primary = WM831X_AUXADC_INT,
208 		.reg = 1,
209 		.mask = WM831X_AUXADC_DATA_EINT,
210 	},
211 	[WM831X_IRQ_AUXADC_DCOMP1] = {
212 		.primary = WM831X_AUXADC_INT,
213 		.reg = 1,
214 		.mask = WM831X_AUXADC_DCOMP1_EINT,
215 	},
216 	[WM831X_IRQ_AUXADC_DCOMP2] = {
217 		.primary = WM831X_AUXADC_INT,
218 		.reg = 1,
219 		.mask = WM831X_AUXADC_DCOMP2_EINT,
220 	},
221 	[WM831X_IRQ_AUXADC_DCOMP3] = {
222 		.primary = WM831X_AUXADC_INT,
223 		.reg = 1,
224 		.mask = WM831X_AUXADC_DCOMP3_EINT,
225 	},
226 	[WM831X_IRQ_AUXADC_DCOMP4] = {
227 		.primary = WM831X_AUXADC_INT,
228 		.reg = 1,
229 		.mask = WM831X_AUXADC_DCOMP4_EINT,
230 	},
231 	[WM831X_IRQ_CS1] = {
232 		.primary = WM831X_CS_INT,
233 		.reg = 2,
234 		.mask = WM831X_CS1_EINT,
235 	},
236 	[WM831X_IRQ_CS2] = {
237 		.primary = WM831X_CS_INT,
238 		.reg = 2,
239 		.mask = WM831X_CS2_EINT,
240 	},
241 	[WM831X_IRQ_HC_DC1] = {
242 		.primary = WM831X_HC_INT,
243 		.reg = 4,
244 		.mask = WM831X_HC_DC1_EINT,
245 	},
246 	[WM831X_IRQ_HC_DC2] = {
247 		.primary = WM831X_HC_INT,
248 		.reg = 4,
249 		.mask = WM831X_HC_DC2_EINT,
250 	},
251 	[WM831X_IRQ_UV_LDO1] = {
252 		.primary = WM831X_UV_INT,
253 		.reg = 3,
254 		.mask = WM831X_UV_LDO1_EINT,
255 	},
256 	[WM831X_IRQ_UV_LDO2] = {
257 		.primary = WM831X_UV_INT,
258 		.reg = 3,
259 		.mask = WM831X_UV_LDO2_EINT,
260 	},
261 	[WM831X_IRQ_UV_LDO3] = {
262 		.primary = WM831X_UV_INT,
263 		.reg = 3,
264 		.mask = WM831X_UV_LDO3_EINT,
265 	},
266 	[WM831X_IRQ_UV_LDO4] = {
267 		.primary = WM831X_UV_INT,
268 		.reg = 3,
269 		.mask = WM831X_UV_LDO4_EINT,
270 	},
271 	[WM831X_IRQ_UV_LDO5] = {
272 		.primary = WM831X_UV_INT,
273 		.reg = 3,
274 		.mask = WM831X_UV_LDO5_EINT,
275 	},
276 	[WM831X_IRQ_UV_LDO6] = {
277 		.primary = WM831X_UV_INT,
278 		.reg = 3,
279 		.mask = WM831X_UV_LDO6_EINT,
280 	},
281 	[WM831X_IRQ_UV_LDO7] = {
282 		.primary = WM831X_UV_INT,
283 		.reg = 3,
284 		.mask = WM831X_UV_LDO7_EINT,
285 	},
286 	[WM831X_IRQ_UV_LDO8] = {
287 		.primary = WM831X_UV_INT,
288 		.reg = 3,
289 		.mask = WM831X_UV_LDO8_EINT,
290 	},
291 	[WM831X_IRQ_UV_LDO9] = {
292 		.primary = WM831X_UV_INT,
293 		.reg = 3,
294 		.mask = WM831X_UV_LDO9_EINT,
295 	},
296 	[WM831X_IRQ_UV_LDO10] = {
297 		.primary = WM831X_UV_INT,
298 		.reg = 3,
299 		.mask = WM831X_UV_LDO10_EINT,
300 	},
301 	[WM831X_IRQ_UV_DC1] = {
302 		.primary = WM831X_UV_INT,
303 		.reg = 4,
304 		.mask = WM831X_UV_DC1_EINT,
305 	},
306 	[WM831X_IRQ_UV_DC2] = {
307 		.primary = WM831X_UV_INT,
308 		.reg = 4,
309 		.mask = WM831X_UV_DC2_EINT,
310 	},
311 	[WM831X_IRQ_UV_DC3] = {
312 		.primary = WM831X_UV_INT,
313 		.reg = 4,
314 		.mask = WM831X_UV_DC3_EINT,
315 	},
316 	[WM831X_IRQ_UV_DC4] = {
317 		.primary = WM831X_UV_INT,
318 		.reg = 4,
319 		.mask = WM831X_UV_DC4_EINT,
320 	},
321 };
322 
323 static inline int irq_data_to_status_reg(struct wm831x_irq_data *irq_data)
324 {
325 	return WM831X_INTERRUPT_STATUS_1 - 1 + irq_data->reg;
326 }
327 
328 static inline int irq_data_to_mask_reg(struct wm831x_irq_data *irq_data)
329 {
330 	return WM831X_INTERRUPT_STATUS_1_MASK - 1 + irq_data->reg;
331 }
332 
333 static inline struct wm831x_irq_data *irq_to_wm831x_irq(struct wm831x *wm831x,
334 							int irq)
335 {
336 	return &wm831x_irqs[irq - wm831x->irq_base];
337 }
338 
339 static void wm831x_irq_lock(struct irq_data *data)
340 {
341 	struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
342 
343 	mutex_lock(&wm831x->irq_lock);
344 }
345 
346 static void wm831x_irq_sync_unlock(struct irq_data *data)
347 {
348 	struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
349 	int i;
350 
351 	for (i = 0; i < ARRAY_SIZE(wm831x->gpio_update); i++) {
352 		if (wm831x->gpio_update[i]) {
353 			wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + i,
354 					WM831X_GPN_INT_MODE | WM831X_GPN_POL,
355 					wm831x->gpio_update[i]);
356 			wm831x->gpio_update[i] = 0;
357 		}
358 	}
359 
360 	for (i = 0; i < ARRAY_SIZE(wm831x->irq_masks_cur); i++) {
361 		/* If there's been a change in the mask write it back
362 		 * to the hardware. */
363 		if (wm831x->irq_masks_cur[i] != wm831x->irq_masks_cache[i]) {
364 			dev_dbg(wm831x->dev, "IRQ mask sync: %x = %x\n",
365 				WM831X_INTERRUPT_STATUS_1_MASK + i,
366 				wm831x->irq_masks_cur[i]);
367 
368 			wm831x->irq_masks_cache[i] = wm831x->irq_masks_cur[i];
369 			wm831x_reg_write(wm831x,
370 					 WM831X_INTERRUPT_STATUS_1_MASK + i,
371 					 wm831x->irq_masks_cur[i]);
372 		}
373 	}
374 
375 	mutex_unlock(&wm831x->irq_lock);
376 }
377 
378 static void wm831x_irq_enable(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->irq);
383 
384 	wm831x->irq_masks_cur[irq_data->reg - 1] &= ~irq_data->mask;
385 }
386 
387 static void wm831x_irq_disable(struct irq_data *data)
388 {
389 	struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
390 	struct wm831x_irq_data *irq_data = irq_to_wm831x_irq(wm831x,
391 							     data->irq);
392 
393 	wm831x->irq_masks_cur[irq_data->reg - 1] |= irq_data->mask;
394 }
395 
396 static int wm831x_irq_set_type(struct irq_data *data, unsigned int type)
397 {
398 	struct wm831x *wm831x = irq_data_get_irq_chip_data(data);
399 	int irq;
400 
401 	irq = data->irq - wm831x->irq_base;
402 
403 	if (irq < WM831X_IRQ_GPIO_1 || irq > WM831X_IRQ_GPIO_11) {
404 		/* Ignore internal-only IRQs */
405 		if (irq >= 0 && irq < WM831X_NUM_IRQS)
406 			return 0;
407 		else
408 			return -EINVAL;
409 	}
410 
411 	/* Rebase the IRQ into the GPIO range so we've got a sensible array
412 	 * index.
413 	 */
414 	irq -= WM831X_IRQ_GPIO_1;
415 
416 	/* We set the high bit to flag that we need an update; don't
417 	 * do the update here as we can be called with the bus lock
418 	 * held.
419 	 */
420 	switch (type) {
421 	case IRQ_TYPE_EDGE_BOTH:
422 		wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_INT_MODE;
423 		wm831x->gpio_level[irq] = false;
424 		break;
425 	case IRQ_TYPE_EDGE_RISING:
426 		wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_POL;
427 		wm831x->gpio_level[irq] = false;
428 		break;
429 	case IRQ_TYPE_EDGE_FALLING:
430 		wm831x->gpio_update[irq] = 0x10000;
431 		wm831x->gpio_level[irq] = false;
432 		break;
433 	case IRQ_TYPE_LEVEL_HIGH:
434 		wm831x->gpio_update[irq] = 0x10000 | WM831X_GPN_POL;
435 		wm831x->gpio_level[irq] = true;
436 		break;
437 	default:
438 		return -EINVAL;
439 	}
440 
441 	return 0;
442 }
443 
444 static struct irq_chip wm831x_irq_chip = {
445 	.name			= "wm831x",
446 	.irq_bus_lock		= wm831x_irq_lock,
447 	.irq_bus_sync_unlock	= wm831x_irq_sync_unlock,
448 	.irq_disable		= wm831x_irq_disable,
449 	.irq_enable		= wm831x_irq_enable,
450 	.irq_set_type		= wm831x_irq_set_type,
451 };
452 
453 /* The processing of the primary interrupt occurs in a thread so that
454  * we can interact with the device over I2C or SPI. */
455 static irqreturn_t wm831x_irq_thread(int irq, void *data)
456 {
457 	struct wm831x *wm831x = data;
458 	unsigned int i;
459 	int primary, status_addr, ret;
460 	int status_regs[WM831X_NUM_IRQ_REGS] = { 0 };
461 	int read[WM831X_NUM_IRQ_REGS] = { 0 };
462 	int *status;
463 
464 	primary = wm831x_reg_read(wm831x, WM831X_SYSTEM_INTERRUPTS);
465 	if (primary < 0) {
466 		dev_err(wm831x->dev, "Failed to read system interrupt: %d\n",
467 			primary);
468 		goto out;
469 	}
470 
471 	/* The touch interrupts are visible in the primary register as
472 	 * an optimisation; open code this to avoid complicating the
473 	 * main handling loop and so we can also skip iterating the
474 	 * descriptors.
475 	 */
476 	if (primary & WM831X_TCHPD_INT)
477 		handle_nested_irq(wm831x->irq_base + WM831X_IRQ_TCHPD);
478 	if (primary & WM831X_TCHDATA_INT)
479 		handle_nested_irq(wm831x->irq_base + WM831X_IRQ_TCHDATA);
480 	if (primary & (WM831X_TCHDATA_EINT | WM831X_TCHPD_EINT))
481 		goto out;
482 
483 	for (i = 0; i < ARRAY_SIZE(wm831x_irqs); i++) {
484 		int offset = wm831x_irqs[i].reg - 1;
485 
486 		if (!(primary & wm831x_irqs[i].primary))
487 			continue;
488 
489 		status = &status_regs[offset];
490 
491 		/* Hopefully there should only be one register to read
492 		 * each time otherwise we ought to do a block read. */
493 		if (!read[offset]) {
494 			status_addr = irq_data_to_status_reg(&wm831x_irqs[i]);
495 
496 			*status = wm831x_reg_read(wm831x, status_addr);
497 			if (*status < 0) {
498 				dev_err(wm831x->dev,
499 					"Failed to read IRQ status: %d\n",
500 					*status);
501 				goto out;
502 			}
503 
504 			read[offset] = 1;
505 
506 			/* Ignore any bits that we don't think are masked */
507 			*status &= ~wm831x->irq_masks_cur[offset];
508 
509 			/* Acknowledge now so we don't miss
510 			 * notifications while we handle.
511 			 */
512 			wm831x_reg_write(wm831x, status_addr, *status);
513 		}
514 
515 		if (*status & wm831x_irqs[i].mask)
516 			handle_nested_irq(wm831x->irq_base + i);
517 
518 		/* Simulate an edge triggered IRQ by polling the input
519 		 * status.  This is sucky but improves interoperability.
520 		 */
521 		if (primary == WM831X_GP_INT &&
522 		    wm831x->gpio_level[i - WM831X_IRQ_GPIO_1]) {
523 			ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
524 			while (ret & 1 << (i - WM831X_IRQ_GPIO_1)) {
525 				handle_nested_irq(wm831x->irq_base + i);
526 				ret = wm831x_reg_read(wm831x,
527 						      WM831X_GPIO_LEVEL);
528 			}
529 		}
530 	}
531 
532 out:
533 	return IRQ_HANDLED;
534 }
535 
536 int wm831x_irq_init(struct wm831x *wm831x, int irq)
537 {
538 	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
539 	int i, cur_irq, ret;
540 
541 	mutex_init(&wm831x->irq_lock);
542 
543 	/* Mask the individual interrupt sources */
544 	for (i = 0; i < ARRAY_SIZE(wm831x->irq_masks_cur); i++) {
545 		wm831x->irq_masks_cur[i] = 0xffff;
546 		wm831x->irq_masks_cache[i] = 0xffff;
547 		wm831x_reg_write(wm831x, WM831X_INTERRUPT_STATUS_1_MASK + i,
548 				 0xffff);
549 	}
550 
551 	/* Try to dynamically allocate IRQs if no base is specified */
552 	if (!pdata || !pdata->irq_base)
553 		wm831x->irq_base = -1;
554 	else
555 		wm831x->irq_base = pdata->irq_base;
556 
557 	wm831x->irq_base = irq_alloc_descs(wm831x->irq_base, 0,
558 					   WM831X_NUM_IRQS, 0);
559 	if (wm831x->irq_base < 0) {
560 		dev_warn(wm831x->dev, "Failed to allocate IRQs: %d\n",
561 			 wm831x->irq_base);
562 		wm831x->irq_base = 0;
563 		return 0;
564 	}
565 
566 	if (pdata && pdata->irq_cmos)
567 		i = 0;
568 	else
569 		i = WM831X_IRQ_OD;
570 
571 	wm831x_set_bits(wm831x, WM831X_IRQ_CONFIG,
572 			WM831X_IRQ_OD, i);
573 
574 	/* Try to flag /IRQ as a wake source; there are a number of
575 	 * unconditional wake sources in the PMIC so this isn't
576 	 * conditional but we don't actually care *too* much if it
577 	 * fails.
578 	 */
579 	ret = enable_irq_wake(irq);
580 	if (ret != 0) {
581 		dev_warn(wm831x->dev, "Can't enable IRQ as wake source: %d\n",
582 			 ret);
583 	}
584 
585 	wm831x->irq = irq;
586 
587 	/* Register them with genirq */
588 	for (cur_irq = wm831x->irq_base;
589 	     cur_irq < ARRAY_SIZE(wm831x_irqs) + wm831x->irq_base;
590 	     cur_irq++) {
591 		irq_set_chip_data(cur_irq, wm831x);
592 		irq_set_chip_and_handler(cur_irq, &wm831x_irq_chip,
593 					 handle_edge_irq);
594 		irq_set_nested_thread(cur_irq, 1);
595 
596 		/* ARM needs us to explicitly flag the IRQ as valid
597 		 * and will set them noprobe when we do so. */
598 #ifdef CONFIG_ARM
599 		set_irq_flags(cur_irq, IRQF_VALID);
600 #else
601 		irq_set_noprobe(cur_irq);
602 #endif
603 	}
604 
605 	if (irq) {
606 		ret = request_threaded_irq(irq, NULL, wm831x_irq_thread,
607 					   IRQF_TRIGGER_LOW | IRQF_ONESHOT,
608 					   "wm831x", wm831x);
609 		if (ret != 0) {
610 			dev_err(wm831x->dev, "Failed to request IRQ %d: %d\n",
611 				irq, ret);
612 			return ret;
613 		}
614 	} else {
615 		dev_warn(wm831x->dev,
616 			 "No interrupt specified - functionality limited\n");
617 	}
618 
619 	/* Enable top level interrupts, we mask at secondary level */
620 	wm831x_reg_write(wm831x, WM831X_SYSTEM_INTERRUPTS_MASK, 0);
621 
622 	return 0;
623 }
624 
625 void wm831x_irq_exit(struct wm831x *wm831x)
626 {
627 	if (wm831x->irq)
628 		free_irq(wm831x->irq, wm831x);
629 }
630