xref: /openbmc/linux/drivers/mfd/twl4030-irq.c (revision b8bb76713ec50df2f11efee386e16f93d51e1076)
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 	struct irq_desc *desc = irq_to_desc(irq);
184 	static unsigned i2c_errors;
185 	const static unsigned max_i2c_errors = 100;
186 
187 	if (!desc) {
188 		pr_err("twl4030: Invalid IRQ: %ld\n", irq);
189 		return -EINVAL;
190 	}
191 
192 	current->flags |= PF_NOFREEZE;
193 
194 	while (!kthread_should_stop()) {
195 		int ret;
196 		int module_irq;
197 		u8 pih_isr;
198 
199 		/* Wait for IRQ, then read PIH irq status (also blocking) */
200 		wait_for_completion_interruptible(&irq_event);
201 
202 		ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr,
203 					  REG_PIH_ISR_P1);
204 		if (ret) {
205 			pr_warning("twl4030: I2C error %d reading PIH ISR\n",
206 					ret);
207 			if (++i2c_errors >= max_i2c_errors) {
208 				printk(KERN_ERR "Maximum I2C error count"
209 						" exceeded.  Terminating %s.\n",
210 						__func__);
211 				break;
212 			}
213 			complete(&irq_event);
214 			continue;
215 		}
216 
217 		/* these handlers deal with the relevant SIH irq status */
218 		local_irq_disable();
219 		for (module_irq = twl4030_irq_base;
220 				pih_isr;
221 				pih_isr >>= 1, module_irq++) {
222 			if (pih_isr & 0x1) {
223 				struct irq_desc *d = irq_to_desc(module_irq);
224 
225 				if (!d) {
226 					pr_err("twl4030: Invalid SIH IRQ: %d\n",
227 					       module_irq);
228 					return -EINVAL;
229 				}
230 
231 				/* These can't be masked ... always warn
232 				 * if we get any surprises.
233 				 */
234 				if (d->status & IRQ_DISABLED)
235 					note_interrupt(module_irq, d,
236 							IRQ_NONE);
237 				else
238 					d->handle_irq(module_irq, d);
239 			}
240 		}
241 		local_irq_enable();
242 
243 		desc->chip->unmask(irq);
244 	}
245 
246 	return 0;
247 }
248 
249 /*
250  * handle_twl4030_pih() is the desc->handle method for the twl4030 interrupt.
251  * This is a chained interrupt, so there is no desc->action method for it.
252  * Now we need to query the interrupt controller in the twl4030 to determine
253  * which module is generating the interrupt request.  However, we can't do i2c
254  * transactions in interrupt context, so we must defer that work to a kernel
255  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
256  * the kernel thread.
257  */
258 static void handle_twl4030_pih(unsigned int irq, irq_desc_t *desc)
259 {
260 	/* Acknowledge, clear *AND* mask the interrupt... */
261 	desc->chip->ack(irq);
262 	complete(&irq_event);
263 }
264 
265 static struct task_struct *start_twl4030_irq_thread(long irq)
266 {
267 	struct task_struct *thread;
268 
269 	init_completion(&irq_event);
270 	thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq");
271 	if (!thread)
272 		pr_err("twl4030: could not create irq %ld thread!\n", irq);
273 
274 	return thread;
275 }
276 
277 /*----------------------------------------------------------------------*/
278 
279 /*
280  * twl4030_init_sih_modules() ... start from a known state where no
281  * IRQs will be coming in, and where we can quickly enable them then
282  * handle them as they arrive.  Mask all IRQs: maybe init SIH_CTRL.
283  *
284  * NOTE:  we don't touch EDR registers here; they stay with hardware
285  * defaults or whatever the last value was.  Note that when both EDR
286  * bits for an IRQ are clear, that's as if its IMR bit is set...
287  */
288 static int twl4030_init_sih_modules(unsigned line)
289 {
290 	const struct sih *sih;
291 	u8 buf[4];
292 	int i;
293 	int status;
294 
295 	/* line 0 == int1_n signal; line 1 == int2_n signal */
296 	if (line > 1)
297 		return -EINVAL;
298 
299 	irq_line = line;
300 
301 	/* disable all interrupts on our line */
302 	memset(buf, 0xff, sizeof buf);
303 	sih = sih_modules;
304 	for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
305 
306 		/* skip USB -- it's funky */
307 		if (!sih->bytes_ixr)
308 			continue;
309 
310 		status = twl4030_i2c_write(sih->module, buf,
311 				sih->mask[line].imr_offset, sih->bytes_ixr);
312 		if (status < 0)
313 			pr_err("twl4030: err %d initializing %s %s\n",
314 					status, sih->name, "IMR");
315 
316 		/* Maybe disable "exclusive" mode; buffer second pending irq;
317 		 * set Clear-On-Read (COR) bit.
318 		 *
319 		 * NOTE that sometimes COR polarity is documented as being
320 		 * inverted:  for MADC and BCI, COR=1 means "clear on write".
321 		 * And for PWR_INT it's not documented...
322 		 */
323 		if (sih->set_cor) {
324 			status = twl4030_i2c_write_u8(sih->module,
325 					TWL4030_SIH_CTRL_COR_MASK,
326 					sih->control_offset);
327 			if (status < 0)
328 				pr_err("twl4030: err %d initializing %s %s\n",
329 						status, sih->name, "SIH_CTRL");
330 		}
331 	}
332 
333 	sih = sih_modules;
334 	for (i = 0; i < ARRAY_SIZE(sih_modules); i++, sih++) {
335 		u8 rxbuf[4];
336 		int j;
337 
338 		/* skip USB */
339 		if (!sih->bytes_ixr)
340 			continue;
341 
342 		/* Clear pending interrupt status.  Either the read was
343 		 * enough, or we need to write those bits.  Repeat, in
344 		 * case an IRQ is pending (PENDDIS=0) ... that's not
345 		 * uncommon with PWR_INT.PWRON.
346 		 */
347 		for (j = 0; j < 2; j++) {
348 			status = twl4030_i2c_read(sih->module, rxbuf,
349 				sih->mask[line].isr_offset, sih->bytes_ixr);
350 			if (status < 0)
351 				pr_err("twl4030: err %d initializing %s %s\n",
352 					status, sih->name, "ISR");
353 
354 			if (!sih->set_cor)
355 				status = twl4030_i2c_write(sih->module, buf,
356 					sih->mask[line].isr_offset,
357 					sih->bytes_ixr);
358 			/* else COR=1 means read sufficed.
359 			 * (for most SIH modules...)
360 			 */
361 		}
362 	}
363 
364 	return 0;
365 }
366 
367 static inline void activate_irq(int irq)
368 {
369 #ifdef CONFIG_ARM
370 	/* ARM requires an extra step to clear IRQ_NOREQUEST, which it
371 	 * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
372 	 */
373 	set_irq_flags(irq, IRQF_VALID);
374 #else
375 	/* same effect on other architectures */
376 	set_irq_noprobe(irq);
377 #endif
378 }
379 
380 /*----------------------------------------------------------------------*/
381 
382 static DEFINE_SPINLOCK(sih_agent_lock);
383 
384 static struct workqueue_struct *wq;
385 
386 struct sih_agent {
387 	int			irq_base;
388 	const struct sih	*sih;
389 
390 	u32			imr;
391 	bool			imr_change_pending;
392 	struct work_struct	mask_work;
393 
394 	u32			edge_change;
395 	struct work_struct	edge_work;
396 };
397 
398 static void twl4030_sih_do_mask(struct work_struct *work)
399 {
400 	struct sih_agent	*agent;
401 	const struct sih	*sih;
402 	union {
403 		u8	bytes[4];
404 		u32	word;
405 	}			imr;
406 	int			status;
407 
408 	agent = container_of(work, struct sih_agent, mask_work);
409 
410 	/* see what work we have */
411 	spin_lock_irq(&sih_agent_lock);
412 	if (agent->imr_change_pending) {
413 		sih = agent->sih;
414 		/* byte[0] gets overwritten as we write ... */
415 		imr.word = cpu_to_le32(agent->imr << 8);
416 		agent->imr_change_pending = false;
417 	} else
418 		sih = NULL;
419 	spin_unlock_irq(&sih_agent_lock);
420 	if (!sih)
421 		return;
422 
423 	/* write the whole mask ... simpler than subsetting it */
424 	status = twl4030_i2c_write(sih->module, imr.bytes,
425 			sih->mask[irq_line].imr_offset, sih->bytes_ixr);
426 	if (status)
427 		pr_err("twl4030: %s, %s --> %d\n", __func__,
428 				"write", status);
429 }
430 
431 static void twl4030_sih_do_edge(struct work_struct *work)
432 {
433 	struct sih_agent	*agent;
434 	const struct sih	*sih;
435 	u8			bytes[6];
436 	u32			edge_change;
437 	int			status;
438 
439 	agent = container_of(work, struct sih_agent, edge_work);
440 
441 	/* see what work we have */
442 	spin_lock_irq(&sih_agent_lock);
443 	edge_change = agent->edge_change;
444 	agent->edge_change = 0;;
445 	sih = edge_change ? agent->sih : NULL;
446 	spin_unlock_irq(&sih_agent_lock);
447 	if (!sih)
448 		return;
449 
450 	/* Read, reserving first byte for write scratch.  Yes, this
451 	 * could be cached for some speedup ... but be careful about
452 	 * any processor on the other IRQ line, EDR registers are
453 	 * shared.
454 	 */
455 	status = twl4030_i2c_read(sih->module, bytes + 1,
456 			sih->edr_offset, sih->bytes_edr);
457 	if (status) {
458 		pr_err("twl4030: %s, %s --> %d\n", __func__,
459 				"read", status);
460 		return;
461 	}
462 
463 	/* Modify only the bits we know must change */
464 	while (edge_change) {
465 		int		i = fls(edge_change) - 1;
466 		struct irq_desc	*d = irq_to_desc(i + agent->irq_base);
467 		int		byte = 1 + (i >> 2);
468 		int		off = (i & 0x3) * 2;
469 
470 		if (!d) {
471 			pr_err("twl4030: Invalid IRQ: %d\n",
472 			       i + agent->irq_base);
473 			return;
474 		}
475 
476 		bytes[byte] &= ~(0x03 << off);
477 
478 		spin_lock_irq(&d->lock);
479 		if (d->status & IRQ_TYPE_EDGE_RISING)
480 			bytes[byte] |= BIT(off + 1);
481 		if (d->status & IRQ_TYPE_EDGE_FALLING)
482 			bytes[byte] |= BIT(off + 0);
483 		spin_unlock_irq(&d->lock);
484 
485 		edge_change &= ~BIT(i);
486 	}
487 
488 	/* Write */
489 	status = twl4030_i2c_write(sih->module, bytes,
490 			sih->edr_offset, sih->bytes_edr);
491 	if (status)
492 		pr_err("twl4030: %s, %s --> %d\n", __func__,
493 				"write", status);
494 }
495 
496 /*----------------------------------------------------------------------*/
497 
498 /*
499  * All irq_chip methods get issued from code holding irq_desc[irq].lock,
500  * which can't perform the underlying I2C operations (because they sleep).
501  * So we must hand them off to a thread (workqueue) and cope with asynch
502  * completion, potentially including some re-ordering, of these requests.
503  */
504 
505 static void twl4030_sih_mask(unsigned irq)
506 {
507 	struct sih_agent *sih = get_irq_chip_data(irq);
508 	unsigned long flags;
509 
510 	spin_lock_irqsave(&sih_agent_lock, flags);
511 	sih->imr |= BIT(irq - sih->irq_base);
512 	sih->imr_change_pending = true;
513 	queue_work(wq, &sih->mask_work);
514 	spin_unlock_irqrestore(&sih_agent_lock, flags);
515 }
516 
517 static void twl4030_sih_unmask(unsigned irq)
518 {
519 	struct sih_agent *sih = get_irq_chip_data(irq);
520 	unsigned long flags;
521 
522 	spin_lock_irqsave(&sih_agent_lock, flags);
523 	sih->imr &= ~BIT(irq - sih->irq_base);
524 	sih->imr_change_pending = true;
525 	queue_work(wq, &sih->mask_work);
526 	spin_unlock_irqrestore(&sih_agent_lock, flags);
527 }
528 
529 static int twl4030_sih_set_type(unsigned irq, unsigned trigger)
530 {
531 	struct sih_agent *sih = get_irq_chip_data(irq);
532 	struct irq_desc *desc = irq_to_desc(irq);
533 	unsigned long flags;
534 
535 	if (!desc) {
536 		pr_err("twl4030: Invalid IRQ: %d\n", irq);
537 		return -EINVAL;
538 	}
539 
540 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
541 		return -EINVAL;
542 
543 	spin_lock_irqsave(&sih_agent_lock, flags);
544 	if ((desc->status & IRQ_TYPE_SENSE_MASK) != trigger) {
545 		desc->status &= ~IRQ_TYPE_SENSE_MASK;
546 		desc->status |= trigger;
547 		sih->edge_change |= BIT(irq - sih->irq_base);
548 		queue_work(wq, &sih->edge_work);
549 	}
550 	spin_unlock_irqrestore(&sih_agent_lock, flags);
551 	return 0;
552 }
553 
554 static struct irq_chip twl4030_sih_irq_chip = {
555 	.name		= "twl4030",
556 	.mask		= twl4030_sih_mask,
557 	.unmask		= twl4030_sih_unmask,
558 	.set_type	= twl4030_sih_set_type,
559 };
560 
561 /*----------------------------------------------------------------------*/
562 
563 static inline int sih_read_isr(const struct sih *sih)
564 {
565 	int status;
566 	union {
567 		u8 bytes[4];
568 		u32 word;
569 	} isr;
570 
571 	/* FIXME need retry-on-error ... */
572 
573 	isr.word = 0;
574 	status = twl4030_i2c_read(sih->module, isr.bytes,
575 			sih->mask[irq_line].isr_offset, sih->bytes_ixr);
576 
577 	return (status < 0) ? status : le32_to_cpu(isr.word);
578 }
579 
580 /*
581  * Generic handler for SIH interrupts ... we "know" this is called
582  * in task context, with IRQs enabled.
583  */
584 static void handle_twl4030_sih(unsigned irq, struct irq_desc *desc)
585 {
586 	struct sih_agent *agent = get_irq_data(irq);
587 	const struct sih *sih = agent->sih;
588 	int isr;
589 
590 	/* reading ISR acks the IRQs, using clear-on-read mode */
591 	local_irq_enable();
592 	isr = sih_read_isr(sih);
593 	local_irq_disable();
594 
595 	if (isr < 0) {
596 		pr_err("twl4030: %s SIH, read ISR error %d\n",
597 			sih->name, isr);
598 		/* REVISIT:  recover; eventually mask it all, etc */
599 		return;
600 	}
601 
602 	while (isr) {
603 		irq = fls(isr);
604 		irq--;
605 		isr &= ~BIT(irq);
606 
607 		if (irq < sih->bits)
608 			generic_handle_irq(agent->irq_base + irq);
609 		else
610 			pr_err("twl4030: %s SIH, invalid ISR bit %d\n",
611 				sih->name, irq);
612 	}
613 }
614 
615 static unsigned twl4030_irq_next;
616 
617 /* returns the first IRQ used by this SIH bank,
618  * or negative errno
619  */
620 int twl4030_sih_setup(int module)
621 {
622 	int			sih_mod;
623 	const struct sih	*sih = NULL;
624 	struct sih_agent	*agent;
625 	int			i, irq;
626 	int			status = -EINVAL;
627 	unsigned		irq_base = twl4030_irq_next;
628 
629 	/* only support modules with standard clear-on-read for now */
630 	for (sih_mod = 0, sih = sih_modules;
631 			sih_mod < ARRAY_SIZE(sih_modules);
632 			sih_mod++, sih++) {
633 		if (sih->module == module && sih->set_cor) {
634 			if (!WARN((irq_base + sih->bits) > NR_IRQS,
635 					"irq %d for %s too big\n",
636 					irq_base + sih->bits,
637 					sih->name))
638 				status = 0;
639 			break;
640 		}
641 	}
642 	if (status < 0)
643 		return status;
644 
645 	agent = kzalloc(sizeof *agent, GFP_KERNEL);
646 	if (!agent)
647 		return -ENOMEM;
648 
649 	status = 0;
650 
651 	agent->irq_base = irq_base;
652 	agent->sih = sih;
653 	agent->imr = ~0;
654 	INIT_WORK(&agent->mask_work, twl4030_sih_do_mask);
655 	INIT_WORK(&agent->edge_work, twl4030_sih_do_edge);
656 
657 	for (i = 0; i < sih->bits; i++) {
658 		irq = irq_base + i;
659 
660 		set_irq_chip_and_handler(irq, &twl4030_sih_irq_chip,
661 				handle_edge_irq);
662 		set_irq_chip_data(irq, agent);
663 		activate_irq(irq);
664 	}
665 
666 	status = irq_base;
667 	twl4030_irq_next += i;
668 
669 	/* replace generic PIH handler (handle_simple_irq) */
670 	irq = sih_mod + twl4030_irq_base;
671 	set_irq_data(irq, agent);
672 	set_irq_chained_handler(irq, handle_twl4030_sih);
673 
674 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", sih->name,
675 			irq, irq_base, twl4030_irq_next - 1);
676 
677 	return status;
678 }
679 
680 /* FIXME need a call to reverse twl4030_sih_setup() ... */
681 
682 
683 /*----------------------------------------------------------------------*/
684 
685 /* FIXME pass in which interrupt line we'll use ... */
686 #define twl_irq_line	0
687 
688 int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
689 {
690 	static struct irq_chip	twl4030_irq_chip;
691 
692 	int			status;
693 	int			i;
694 	struct task_struct	*task;
695 
696 	/*
697 	 * Mask and clear all TWL4030 interrupts since initially we do
698 	 * not have any TWL4030 module interrupt handlers present
699 	 */
700 	status = twl4030_init_sih_modules(twl_irq_line);
701 	if (status < 0)
702 		return status;
703 
704 	wq = create_singlethread_workqueue("twl4030-irqchip");
705 	if (!wq) {
706 		pr_err("twl4030: workqueue FAIL\n");
707 		return -ESRCH;
708 	}
709 
710 	twl4030_irq_base = irq_base;
711 
712 	/* install an irq handler for each of the SIH modules;
713 	 * clone dummy irq_chip since PIH can't *do* anything
714 	 */
715 	twl4030_irq_chip = dummy_irq_chip;
716 	twl4030_irq_chip.name = "twl4030";
717 
718 	twl4030_sih_irq_chip.ack = dummy_irq_chip.ack;
719 
720 	for (i = irq_base; i < irq_end; i++) {
721 		set_irq_chip_and_handler(i, &twl4030_irq_chip,
722 				handle_simple_irq);
723 		activate_irq(i);
724 	}
725 	twl4030_irq_next = i;
726 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
727 			irq_num, irq_base, twl4030_irq_next - 1);
728 
729 	/* ... and the PWR_INT module ... */
730 	status = twl4030_sih_setup(TWL4030_MODULE_INT);
731 	if (status < 0) {
732 		pr_err("twl4030: sih_setup PWR INT --> %d\n", status);
733 		goto fail;
734 	}
735 
736 	/* install an irq handler to demultiplex the TWL4030 interrupt */
737 	task = start_twl4030_irq_thread(irq_num);
738 	if (!task) {
739 		pr_err("twl4030: irq thread FAIL\n");
740 		status = -ESRCH;
741 		goto fail;
742 	}
743 
744 	set_irq_data(irq_num, task);
745 	set_irq_chained_handler(irq_num, handle_twl4030_pih);
746 
747 	return status;
748 
749 fail:
750 	for (i = irq_base; i < irq_end; i++)
751 		set_irq_chip_and_handler(i, NULL, NULL);
752 	destroy_workqueue(wq);
753 	wq = NULL;
754 	return status;
755 }
756 
757 int twl_exit_irq(void)
758 {
759 	/* FIXME undo twl_init_irq() */
760 	if (twl4030_irq_base) {
761 		pr_err("twl4030: can't yet clean up IRQs?\n");
762 		return -ENOSYS;
763 	}
764 	return 0;
765 }
766