xref: /openbmc/linux/drivers/mfd/twl4030-irq.c (revision fd589a8f)
1 /*
2  * twl4030-irq.c - TWL4030/TPS659x0 irq support
3  *
4  * Copyright (C) 2005-2006 Texas Instruments, Inc.
5  *
6  * Modifications to defer interrupt handling to a kernel thread:
7  * Copyright (C) 2006 MontaVista Software, Inc.
8  *
9  * Based on tlv320aic23.c:
10  * Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
11  *
12  * Code cleanup and modifications to IRQ handler.
13  * by syed khasim <x0khasim@ti.com>
14  *
15  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
28  */
29 
30 #include <linux/init.h>
31 #include <linux/interrupt.h>
32 #include <linux/irq.h>
33 #include <linux/kthread.h>
34 
35 #include <linux/i2c/twl4030.h>
36 
37 
38 /*
39  * TWL4030 IRQ handling has two stages in hardware, and thus in software.
40  * The Primary Interrupt Handler (PIH) stage exposes status bits saying
41  * which Secondary Interrupt Handler (SIH) stage is raising an interrupt.
42  * SIH modules are more traditional IRQ components, which support per-IRQ
43  * enable/disable and trigger controls; they do most of the work.
44  *
45  * These chips are designed to support IRQ handling from two different
46  * I2C masters.  Each has a dedicated IRQ line, and dedicated IRQ status
47  * and mask registers in the PIH and SIH modules.
48  *
49  * We set up IRQs starting at a platform-specified base, always starting
50  * with PIH and the SIH for PWR_INT and then usually adding GPIO:
51  *	base + 0  .. base + 7	PIH
52  *	base + 8  .. base + 15	SIH for PWR_INT
53  *	base + 16 .. base + 33	SIH for GPIO
54  */
55 
56 /* PIH register offsets */
57 #define REG_PIH_ISR_P1			0x01
58 #define REG_PIH_ISR_P2			0x02
59 #define REG_PIH_SIR			0x03	/* for testing */
60 
61 
62 /* Linux could (eventually) use either IRQ line */
63 static int irq_line;
64 
65 struct sih {
66 	char	name[8];
67 	u8	module;			/* module id */
68 	u8	control_offset;		/* for SIH_CTRL */
69 	bool	set_cor;
70 
71 	u8	bits;			/* valid in isr/imr */
72 	u8	bytes_ixr;		/* bytelen of ISR/IMR/SIR */
73 
74 	u8	edr_offset;
75 	u8	bytes_edr;		/* bytelen of EDR */
76 
77 	/* SIR ignored -- set interrupt, for testing only */
78 	struct irq_data {
79 		u8	isr_offset;
80 		u8	imr_offset;
81 	} mask[2];
82 	/* + 2 bytes padding */
83 };
84 
85 #define SIH_INITIALIZER(modname, nbits) \
86 	.module		= TWL4030_MODULE_ ## modname, \
87 	.control_offset = TWL4030_ ## modname ## _SIH_CTRL, \
88 	.bits		= nbits, \
89 	.bytes_ixr	= DIV_ROUND_UP(nbits, 8), \
90 	.edr_offset	= TWL4030_ ## modname ## _EDR, \
91 	.bytes_edr	= DIV_ROUND_UP((2*(nbits)), 8), \
92 	.mask = { { \
93 		.isr_offset	= TWL4030_ ## modname ## _ISR1, \
94 		.imr_offset	= TWL4030_ ## modname ## _IMR1, \
95 	}, \
96 	{ \
97 		.isr_offset	= TWL4030_ ## modname ## _ISR2, \
98 		.imr_offset	= TWL4030_ ## modname ## _IMR2, \
99 	}, },
100 
101 /* register naming policies are inconsistent ... */
102 #define TWL4030_INT_PWR_EDR		TWL4030_INT_PWR_EDR1
103 #define TWL4030_MODULE_KEYPAD_KEYP	TWL4030_MODULE_KEYPAD
104 #define TWL4030_MODULE_INT_PWR		TWL4030_MODULE_INT
105 
106 
107 /* Order in this table matches order in PIH_ISR.  That is,
108  * BIT(n) in PIH_ISR is sih_modules[n].
109  */
110 static const struct sih sih_modules[6] = {
111 	[0] = {
112 		.name		= "gpio",
113 		.module		= TWL4030_MODULE_GPIO,
114 		.control_offset	= REG_GPIO_SIH_CTRL,
115 		.set_cor	= true,
116 		.bits		= TWL4030_GPIO_MAX,
117 		.bytes_ixr	= 3,
118 		/* Note: *all* of these IRQs default to no-trigger */
119 		.edr_offset	= REG_GPIO_EDR1,
120 		.bytes_edr	= 5,
121 		.mask = { {
122 			.isr_offset	= REG_GPIO_ISR1A,
123 			.imr_offset	= REG_GPIO_IMR1A,
124 		}, {
125 			.isr_offset	= REG_GPIO_ISR1B,
126 			.imr_offset	= REG_GPIO_IMR1B,
127 		}, },
128 	},
129 	[1] = {
130 		.name		= "keypad",
131 		.set_cor	= true,
132 		SIH_INITIALIZER(KEYPAD_KEYP, 4)
133 	},
134 	[2] = {
135 		.name		= "bci",
136 		.module		= TWL4030_MODULE_INTERRUPTS,
137 		.control_offset	= TWL4030_INTERRUPTS_BCISIHCTRL,
138 		.bits		= 12,
139 		.bytes_ixr	= 2,
140 		.edr_offset	= TWL4030_INTERRUPTS_BCIEDR1,
141 		/* Note: most of these IRQs default to no-trigger */
142 		.bytes_edr	= 3,
143 		.mask = { {
144 			.isr_offset	= TWL4030_INTERRUPTS_BCIISR1A,
145 			.imr_offset	= TWL4030_INTERRUPTS_BCIIMR1A,
146 		}, {
147 			.isr_offset	= TWL4030_INTERRUPTS_BCIISR1B,
148 			.imr_offset	= TWL4030_INTERRUPTS_BCIIMR1B,
149 		}, },
150 	},
151 	[3] = {
152 		.name		= "madc",
153 		SIH_INITIALIZER(MADC, 4)
154 	},
155 	[4] = {
156 		/* USB doesn't use the same SIH organization */
157 		.name		= "usb",
158 	},
159 	[5] = {
160 		.name		= "power",
161 		.set_cor	= true,
162 		SIH_INITIALIZER(INT_PWR, 8)
163 	},
164 		/* there are no SIH modules #6 or #7 ... */
165 };
166 
167 #undef TWL4030_MODULE_KEYPAD_KEYP
168 #undef TWL4030_MODULE_INT_PWR
169 #undef TWL4030_INT_PWR_EDR
170 
171 /*----------------------------------------------------------------------*/
172 
173 static unsigned twl4030_irq_base;
174 
175 static struct completion irq_event;
176 
177 /*
178  * This thread processes interrupts reported by the Primary Interrupt Handler.
179  */
180 static int twl4030_irq_thread(void *data)
181 {
182 	long irq = (long)data;
183 	static unsigned i2c_errors;
184 	static const unsigned max_i2c_errors = 100;
185 
186 
187 	current->flags |= PF_NOFREEZE;
188 
189 	while (!kthread_should_stop()) {
190 		int ret;
191 		int module_irq;
192 		u8 pih_isr;
193 
194 		/* Wait for IRQ, then read PIH irq status (also blocking) */
195 		wait_for_completion_interruptible(&irq_event);
196 
197 		ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr,
198 					  REG_PIH_ISR_P1);
199 		if (ret) {
200 			pr_warning("twl4030: I2C error %d reading PIH ISR\n",
201 					ret);
202 			if (++i2c_errors >= max_i2c_errors) {
203 				printk(KERN_ERR "Maximum I2C error count"
204 						" exceeded.  Terminating %s.\n",
205 						__func__);
206 				break;
207 			}
208 			complete(&irq_event);
209 			continue;
210 		}
211 
212 		/* these handlers deal with the relevant SIH irq status */
213 		local_irq_disable();
214 		for (module_irq = twl4030_irq_base;
215 				pih_isr;
216 				pih_isr >>= 1, module_irq++) {
217 			if (pih_isr & 0x1) {
218 				struct irq_desc *d = irq_to_desc(module_irq);
219 
220 				if (!d) {
221 					pr_err("twl4030: Invalid SIH IRQ: %d\n",
222 					       module_irq);
223 					return -EINVAL;
224 				}
225 
226 				/* These can't be masked ... always warn
227 				 * if we get any surprises.
228 				 */
229 				if (d->status & IRQ_DISABLED)
230 					note_interrupt(module_irq, d,
231 							IRQ_NONE);
232 				else
233 					d->handle_irq(module_irq, d);
234 			}
235 		}
236 		local_irq_enable();
237 
238 		enable_irq(irq);
239 	}
240 
241 	return 0;
242 }
243 
244 /*
245  * handle_twl4030_pih() is the desc->handle method for the twl4030 interrupt.
246  * This is a chained interrupt, so there is no desc->action method for it.
247  * Now we need to query the interrupt controller in the twl4030 to determine
248  * which module is generating the interrupt request.  However, we can't do i2c
249  * transactions in interrupt context, so we must defer that work to a kernel
250  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
251  * the kernel thread.
252  */
253 static irqreturn_t handle_twl4030_pih(int irq, void *devid)
254 {
255 	/* Acknowledge, clear *AND* mask the interrupt... */
256 	disable_irq_nosync(irq);
257 	complete(devid);
258 	return IRQ_HANDLED;
259 }
260 /*----------------------------------------------------------------------*/
261 
262 /*
263  * twl4030_init_sih_modules() ... start from a known state where no
264  * IRQs will be coming in, and where we can quickly enable them then
265  * handle them as they arrive.  Mask all IRQs: maybe init SIH_CTRL.
266  *
267  * NOTE:  we don't touch EDR registers here; they stay with hardware
268  * defaults or whatever the last value was.  Note that when both EDR
269  * bits for an IRQ are clear, that's as if its IMR bit is set...
270  */
271 static int twl4030_init_sih_modules(unsigned line)
272 {
273 	const struct sih *sih;
274 	u8 buf[4];
275 	int i;
276 	int status;
277 
278 	/* line 0 == int1_n signal; line 1 == int2_n signal */
279 	if (line > 1)
280 		return -EINVAL;
281 
282 	irq_line = line;
283 
284 	/* disable all interrupts on our line */
285 	memset(buf, 0xff, sizeof buf);
286 	sih = sih_modules;
287 	for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
288 
289 		/* skip USB -- it's funky */
290 		if (!sih->bytes_ixr)
291 			continue;
292 
293 		status = twl4030_i2c_write(sih->module, buf,
294 				sih->mask[line].imr_offset, sih->bytes_ixr);
295 		if (status < 0)
296 			pr_err("twl4030: err %d initializing %s %s\n",
297 					status, sih->name, "IMR");
298 
299 		/* Maybe disable "exclusive" mode; buffer second pending irq;
300 		 * set Clear-On-Read (COR) bit.
301 		 *
302 		 * NOTE that sometimes COR polarity is documented as being
303 		 * inverted:  for MADC and BCI, COR=1 means "clear on write".
304 		 * And for PWR_INT it's not documented...
305 		 */
306 		if (sih->set_cor) {
307 			status = twl4030_i2c_write_u8(sih->module,
308 					TWL4030_SIH_CTRL_COR_MASK,
309 					sih->control_offset);
310 			if (status < 0)
311 				pr_err("twl4030: err %d initializing %s %s\n",
312 						status, sih->name, "SIH_CTRL");
313 		}
314 	}
315 
316 	sih = sih_modules;
317 	for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
318 		u8 rxbuf[4];
319 		int j;
320 
321 		/* skip USB */
322 		if (!sih->bytes_ixr)
323 			continue;
324 
325 		/* Clear pending interrupt status.  Either the read was
326 		 * enough, or we need to write those bits.  Repeat, in
327 		 * case an IRQ is pending (PENDDIS=0) ... that's not
328 		 * uncommon with PWR_INT.PWRON.
329 		 */
330 		for (j = 0; j < 2; j++) {
331 			status = twl4030_i2c_read(sih->module, rxbuf,
332 				sih->mask[line].isr_offset, sih->bytes_ixr);
333 			if (status < 0)
334 				pr_err("twl4030: err %d initializing %s %s\n",
335 					status, sih->name, "ISR");
336 
337 			if (!sih->set_cor)
338 				status = twl4030_i2c_write(sih->module, buf,
339 					sih->mask[line].isr_offset,
340 					sih->bytes_ixr);
341 			/* else COR=1 means read sufficed.
342 			 * (for most SIH modules...)
343 			 */
344 		}
345 	}
346 
347 	return 0;
348 }
349 
350 static inline void activate_irq(int irq)
351 {
352 #ifdef CONFIG_ARM
353 	/* ARM requires an extra step to clear IRQ_NOREQUEST, which it
354 	 * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
355 	 */
356 	set_irq_flags(irq, IRQF_VALID);
357 #else
358 	/* same effect on other architectures */
359 	set_irq_noprobe(irq);
360 #endif
361 }
362 
363 /*----------------------------------------------------------------------*/
364 
365 static DEFINE_SPINLOCK(sih_agent_lock);
366 
367 static struct workqueue_struct *wq;
368 
369 struct sih_agent {
370 	int			irq_base;
371 	const struct sih	*sih;
372 
373 	u32			imr;
374 	bool			imr_change_pending;
375 	struct work_struct	mask_work;
376 
377 	u32			edge_change;
378 	struct work_struct	edge_work;
379 };
380 
381 static void twl4030_sih_do_mask(struct work_struct *work)
382 {
383 	struct sih_agent	*agent;
384 	const struct sih	*sih;
385 	union {
386 		u8	bytes[4];
387 		u32	word;
388 	}			imr;
389 	int			status;
390 
391 	agent = container_of(work, struct sih_agent, mask_work);
392 
393 	/* see what work we have */
394 	spin_lock_irq(&sih_agent_lock);
395 	if (agent->imr_change_pending) {
396 		sih = agent->sih;
397 		/* byte[0] gets overwritten as we write ... */
398 		imr.word = cpu_to_le32(agent->imr << 8);
399 		agent->imr_change_pending = false;
400 	} else
401 		sih = NULL;
402 	spin_unlock_irq(&sih_agent_lock);
403 	if (!sih)
404 		return;
405 
406 	/* write the whole mask ... simpler than subsetting it */
407 	status = twl4030_i2c_write(sih->module, imr.bytes,
408 			sih->mask[irq_line].imr_offset, sih->bytes_ixr);
409 	if (status)
410 		pr_err("twl4030: %s, %s --> %d\n", __func__,
411 				"write", status);
412 }
413 
414 static void twl4030_sih_do_edge(struct work_struct *work)
415 {
416 	struct sih_agent	*agent;
417 	const struct sih	*sih;
418 	u8			bytes[6];
419 	u32			edge_change;
420 	int			status;
421 
422 	agent = container_of(work, struct sih_agent, edge_work);
423 
424 	/* see what work we have */
425 	spin_lock_irq(&sih_agent_lock);
426 	edge_change = agent->edge_change;
427 	agent->edge_change = 0;
428 	sih = edge_change ? agent->sih : NULL;
429 	spin_unlock_irq(&sih_agent_lock);
430 	if (!sih)
431 		return;
432 
433 	/* Read, reserving first byte for write scratch.  Yes, this
434 	 * could be cached for some speedup ... but be careful about
435 	 * any processor on the other IRQ line, EDR registers are
436 	 * shared.
437 	 */
438 	status = twl4030_i2c_read(sih->module, bytes + 1,
439 			sih->edr_offset, sih->bytes_edr);
440 	if (status) {
441 		pr_err("twl4030: %s, %s --> %d\n", __func__,
442 				"read", status);
443 		return;
444 	}
445 
446 	/* Modify only the bits we know must change */
447 	while (edge_change) {
448 		int		i = fls(edge_change) - 1;
449 		struct irq_desc	*d = irq_to_desc(i + agent->irq_base);
450 		int		byte = 1 + (i >> 2);
451 		int		off = (i & 0x3) * 2;
452 
453 		if (!d) {
454 			pr_err("twl4030: Invalid IRQ: %d\n",
455 			       i + agent->irq_base);
456 			return;
457 		}
458 
459 		bytes[byte] &= ~(0x03 << off);
460 
461 		spin_lock_irq(&d->lock);
462 		if (d->status & IRQ_TYPE_EDGE_RISING)
463 			bytes[byte] |= BIT(off + 1);
464 		if (d->status & IRQ_TYPE_EDGE_FALLING)
465 			bytes[byte] |= BIT(off + 0);
466 		spin_unlock_irq(&d->lock);
467 
468 		edge_change &= ~BIT(i);
469 	}
470 
471 	/* Write */
472 	status = twl4030_i2c_write(sih->module, bytes,
473 			sih->edr_offset, sih->bytes_edr);
474 	if (status)
475 		pr_err("twl4030: %s, %s --> %d\n", __func__,
476 				"write", status);
477 }
478 
479 /*----------------------------------------------------------------------*/
480 
481 /*
482  * All irq_chip methods get issued from code holding irq_desc[irq].lock,
483  * which can't perform the underlying I2C operations (because they sleep).
484  * So we must hand them off to a thread (workqueue) and cope with asynch
485  * completion, potentially including some re-ordering, of these requests.
486  */
487 
488 static void twl4030_sih_mask(unsigned irq)
489 {
490 	struct sih_agent *sih = get_irq_chip_data(irq);
491 	unsigned long flags;
492 
493 	spin_lock_irqsave(&sih_agent_lock, flags);
494 	sih->imr |= BIT(irq - sih->irq_base);
495 	sih->imr_change_pending = true;
496 	queue_work(wq, &sih->mask_work);
497 	spin_unlock_irqrestore(&sih_agent_lock, flags);
498 }
499 
500 static void twl4030_sih_unmask(unsigned irq)
501 {
502 	struct sih_agent *sih = get_irq_chip_data(irq);
503 	unsigned long flags;
504 
505 	spin_lock_irqsave(&sih_agent_lock, flags);
506 	sih->imr &= ~BIT(irq - sih->irq_base);
507 	sih->imr_change_pending = true;
508 	queue_work(wq, &sih->mask_work);
509 	spin_unlock_irqrestore(&sih_agent_lock, flags);
510 }
511 
512 static int twl4030_sih_set_type(unsigned irq, unsigned trigger)
513 {
514 	struct sih_agent *sih = get_irq_chip_data(irq);
515 	struct irq_desc *desc = irq_to_desc(irq);
516 	unsigned long flags;
517 
518 	if (!desc) {
519 		pr_err("twl4030: Invalid IRQ: %d\n", irq);
520 		return -EINVAL;
521 	}
522 
523 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
524 		return -EINVAL;
525 
526 	spin_lock_irqsave(&sih_agent_lock, flags);
527 	if ((desc->status & IRQ_TYPE_SENSE_MASK) != trigger) {
528 		desc->status &= ~IRQ_TYPE_SENSE_MASK;
529 		desc->status |= trigger;
530 		sih->edge_change |= BIT(irq - sih->irq_base);
531 		queue_work(wq, &sih->edge_work);
532 	}
533 	spin_unlock_irqrestore(&sih_agent_lock, flags);
534 	return 0;
535 }
536 
537 static struct irq_chip twl4030_sih_irq_chip = {
538 	.name		= "twl4030",
539 	.mask		= twl4030_sih_mask,
540 	.unmask		= twl4030_sih_unmask,
541 	.set_type	= twl4030_sih_set_type,
542 };
543 
544 /*----------------------------------------------------------------------*/
545 
546 static inline int sih_read_isr(const struct sih *sih)
547 {
548 	int status;
549 	union {
550 		u8 bytes[4];
551 		u32 word;
552 	} isr;
553 
554 	/* FIXME need retry-on-error ... */
555 
556 	isr.word = 0;
557 	status = twl4030_i2c_read(sih->module, isr.bytes,
558 			sih->mask[irq_line].isr_offset, sih->bytes_ixr);
559 
560 	return (status < 0) ? status : le32_to_cpu(isr.word);
561 }
562 
563 /*
564  * Generic handler for SIH interrupts ... we "know" this is called
565  * in task context, with IRQs enabled.
566  */
567 static void handle_twl4030_sih(unsigned irq, struct irq_desc *desc)
568 {
569 	struct sih_agent *agent = get_irq_data(irq);
570 	const struct sih *sih = agent->sih;
571 	int isr;
572 
573 	/* reading ISR acks the IRQs, using clear-on-read mode */
574 	local_irq_enable();
575 	isr = sih_read_isr(sih);
576 	local_irq_disable();
577 
578 	if (isr < 0) {
579 		pr_err("twl4030: %s SIH, read ISR error %d\n",
580 			sih->name, isr);
581 		/* REVISIT:  recover; eventually mask it all, etc */
582 		return;
583 	}
584 
585 	while (isr) {
586 		irq = fls(isr);
587 		irq--;
588 		isr &= ~BIT(irq);
589 
590 		if (irq < sih->bits)
591 			generic_handle_irq(agent->irq_base + irq);
592 		else
593 			pr_err("twl4030: %s SIH, invalid ISR bit %d\n",
594 				sih->name, irq);
595 	}
596 }
597 
598 static unsigned twl4030_irq_next;
599 
600 /* returns the first IRQ used by this SIH bank,
601  * or negative errno
602  */
603 int twl4030_sih_setup(int module)
604 {
605 	int			sih_mod;
606 	const struct sih	*sih = NULL;
607 	struct sih_agent	*agent;
608 	int			i, irq;
609 	int			status = -EINVAL;
610 	unsigned		irq_base = twl4030_irq_next;
611 
612 	/* only support modules with standard clear-on-read for now */
613 	for (sih_mod = 0, sih = sih_modules;
614 			sih_mod < ARRAY_SIZE(sih_modules);
615 			sih_mod++, sih++) {
616 		if (sih->module == module && sih->set_cor) {
617 			if (!WARN((irq_base + sih->bits) > NR_IRQS,
618 					"irq %d for %s too big\n",
619 					irq_base + sih->bits,
620 					sih->name))
621 				status = 0;
622 			break;
623 		}
624 	}
625 	if (status < 0)
626 		return status;
627 
628 	agent = kzalloc(sizeof *agent, GFP_KERNEL);
629 	if (!agent)
630 		return -ENOMEM;
631 
632 	status = 0;
633 
634 	agent->irq_base = irq_base;
635 	agent->sih = sih;
636 	agent->imr = ~0;
637 	INIT_WORK(&agent->mask_work, twl4030_sih_do_mask);
638 	INIT_WORK(&agent->edge_work, twl4030_sih_do_edge);
639 
640 	for (i = 0; i < sih->bits; i++) {
641 		irq = irq_base + i;
642 
643 		set_irq_chip_and_handler(irq, &twl4030_sih_irq_chip,
644 				handle_edge_irq);
645 		set_irq_chip_data(irq, agent);
646 		activate_irq(irq);
647 	}
648 
649 	status = irq_base;
650 	twl4030_irq_next += i;
651 
652 	/* replace generic PIH handler (handle_simple_irq) */
653 	irq = sih_mod + twl4030_irq_base;
654 	set_irq_data(irq, agent);
655 	set_irq_chained_handler(irq, handle_twl4030_sih);
656 
657 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", sih->name,
658 			irq, irq_base, twl4030_irq_next - 1);
659 
660 	return status;
661 }
662 
663 /* FIXME need a call to reverse twl4030_sih_setup() ... */
664 
665 
666 /*----------------------------------------------------------------------*/
667 
668 /* FIXME pass in which interrupt line we'll use ... */
669 #define twl_irq_line	0
670 
671 int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
672 {
673 	static struct irq_chip	twl4030_irq_chip;
674 
675 	int			status;
676 	int			i;
677 	struct task_struct	*task;
678 
679 	/*
680 	 * Mask and clear all TWL4030 interrupts since initially we do
681 	 * not have any TWL4030 module interrupt handlers present
682 	 */
683 	status = twl4030_init_sih_modules(twl_irq_line);
684 	if (status < 0)
685 		return status;
686 
687 	wq = create_singlethread_workqueue("twl4030-irqchip");
688 	if (!wq) {
689 		pr_err("twl4030: workqueue FAIL\n");
690 		return -ESRCH;
691 	}
692 
693 	twl4030_irq_base = irq_base;
694 
695 	/* install an irq handler for each of the SIH modules;
696 	 * clone dummy irq_chip since PIH can't *do* anything
697 	 */
698 	twl4030_irq_chip = dummy_irq_chip;
699 	twl4030_irq_chip.name = "twl4030";
700 
701 	twl4030_sih_irq_chip.ack = dummy_irq_chip.ack;
702 
703 	for (i = irq_base; i < irq_end; i++) {
704 		set_irq_chip_and_handler(i, &twl4030_irq_chip,
705 				handle_simple_irq);
706 		activate_irq(i);
707 	}
708 	twl4030_irq_next = i;
709 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
710 			irq_num, irq_base, twl4030_irq_next - 1);
711 
712 	/* ... and the PWR_INT module ... */
713 	status = twl4030_sih_setup(TWL4030_MODULE_INT);
714 	if (status < 0) {
715 		pr_err("twl4030: sih_setup PWR INT --> %d\n", status);
716 		goto fail;
717 	}
718 
719 	/* install an irq handler to demultiplex the TWL4030 interrupt */
720 
721 
722 	init_completion(&irq_event);
723 
724 	status = request_irq(irq_num, handle_twl4030_pih, IRQF_DISABLED,
725 				"TWL4030-PIH", &irq_event);
726 	if (status < 0) {
727 		pr_err("twl4030: could not claim irq%d: %d\n", irq_num, status);
728 		goto fail_rqirq;
729 	}
730 
731 	task = kthread_run(twl4030_irq_thread, (void *)irq_num, "twl4030-irq");
732 	if (IS_ERR(task)) {
733 		pr_err("twl4030: could not create irq %d thread!\n", irq_num);
734 		status = PTR_ERR(task);
735 		goto fail_kthread;
736 	}
737 	return status;
738 fail_kthread:
739 	free_irq(irq_num, &irq_event);
740 fail_rqirq:
741 	/* clean up twl4030_sih_setup */
742 fail:
743 	for (i = irq_base; i < irq_end; i++)
744 		set_irq_chip_and_handler(i, NULL, NULL);
745 	destroy_workqueue(wq);
746 	wq = NULL;
747 	return status;
748 }
749 
750 int twl_exit_irq(void)
751 {
752 	/* FIXME undo twl_init_irq() */
753 	if (twl4030_irq_base) {
754 		pr_err("twl4030: can't yet clean up IRQs?\n");
755 		return -ENOSYS;
756 	}
757 	return 0;
758 }
759