xref: /openbmc/linux/drivers/mfd/twl4030-irq.c (revision a09d2831)
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/twl.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 	u8	irq_lines;		/* number of supported irq lines */
78 
79 	/* SIR ignored -- set interrupt, for testing only */
80 	struct irq_data {
81 		u8	isr_offset;
82 		u8	imr_offset;
83 	} mask[2];
84 	/* + 2 bytes padding */
85 };
86 
87 static const struct sih *sih_modules;
88 static int nr_sih_modules;
89 
90 #define SIH_INITIALIZER(modname, nbits) \
91 	.module		= TWL4030_MODULE_ ## modname, \
92 	.control_offset = TWL4030_ ## modname ## _SIH_CTRL, \
93 	.bits		= nbits, \
94 	.bytes_ixr	= DIV_ROUND_UP(nbits, 8), \
95 	.edr_offset	= TWL4030_ ## modname ## _EDR, \
96 	.bytes_edr	= DIV_ROUND_UP((2*(nbits)), 8), \
97 	.irq_lines	= 2, \
98 	.mask = { { \
99 		.isr_offset	= TWL4030_ ## modname ## _ISR1, \
100 		.imr_offset	= TWL4030_ ## modname ## _IMR1, \
101 	}, \
102 	{ \
103 		.isr_offset	= TWL4030_ ## modname ## _ISR2, \
104 		.imr_offset	= TWL4030_ ## modname ## _IMR2, \
105 	}, },
106 
107 /* register naming policies are inconsistent ... */
108 #define TWL4030_INT_PWR_EDR		TWL4030_INT_PWR_EDR1
109 #define TWL4030_MODULE_KEYPAD_KEYP	TWL4030_MODULE_KEYPAD
110 #define TWL4030_MODULE_INT_PWR		TWL4030_MODULE_INT
111 
112 
113 /* Order in this table matches order in PIH_ISR.  That is,
114  * BIT(n) in PIH_ISR is sih_modules[n].
115  */
116 /* sih_modules_twl4030 is used both in twl4030 and twl5030 */
117 static const struct sih sih_modules_twl4030[6] = {
118 	[0] = {
119 		.name		= "gpio",
120 		.module		= TWL4030_MODULE_GPIO,
121 		.control_offset	= REG_GPIO_SIH_CTRL,
122 		.set_cor	= true,
123 		.bits		= TWL4030_GPIO_MAX,
124 		.bytes_ixr	= 3,
125 		/* Note: *all* of these IRQs default to no-trigger */
126 		.edr_offset	= REG_GPIO_EDR1,
127 		.bytes_edr	= 5,
128 		.irq_lines	= 2,
129 		.mask = { {
130 			.isr_offset	= REG_GPIO_ISR1A,
131 			.imr_offset	= REG_GPIO_IMR1A,
132 		}, {
133 			.isr_offset	= REG_GPIO_ISR1B,
134 			.imr_offset	= REG_GPIO_IMR1B,
135 		}, },
136 	},
137 	[1] = {
138 		.name		= "keypad",
139 		.set_cor	= true,
140 		SIH_INITIALIZER(KEYPAD_KEYP, 4)
141 	},
142 	[2] = {
143 		.name		= "bci",
144 		.module		= TWL4030_MODULE_INTERRUPTS,
145 		.control_offset	= TWL4030_INTERRUPTS_BCISIHCTRL,
146 		.bits		= 12,
147 		.bytes_ixr	= 2,
148 		.edr_offset	= TWL4030_INTERRUPTS_BCIEDR1,
149 		/* Note: most of these IRQs default to no-trigger */
150 		.bytes_edr	= 3,
151 		.irq_lines	= 2,
152 		.mask = { {
153 			.isr_offset	= TWL4030_INTERRUPTS_BCIISR1A,
154 			.imr_offset	= TWL4030_INTERRUPTS_BCIIMR1A,
155 		}, {
156 			.isr_offset	= TWL4030_INTERRUPTS_BCIISR1B,
157 			.imr_offset	= TWL4030_INTERRUPTS_BCIIMR1B,
158 		}, },
159 	},
160 	[3] = {
161 		.name		= "madc",
162 		SIH_INITIALIZER(MADC, 4)
163 	},
164 	[4] = {
165 		/* USB doesn't use the same SIH organization */
166 		.name		= "usb",
167 	},
168 	[5] = {
169 		.name		= "power",
170 		.set_cor	= true,
171 		SIH_INITIALIZER(INT_PWR, 8)
172 	},
173 		/* there are no SIH modules #6 or #7 ... */
174 };
175 
176 static const struct sih sih_modules_twl5031[8] = {
177 	[0] = {
178 		.name		= "gpio",
179 		.module		= TWL4030_MODULE_GPIO,
180 		.control_offset	= REG_GPIO_SIH_CTRL,
181 		.set_cor	= true,
182 		.bits		= TWL4030_GPIO_MAX,
183 		.bytes_ixr	= 3,
184 		/* Note: *all* of these IRQs default to no-trigger */
185 		.edr_offset	= REG_GPIO_EDR1,
186 		.bytes_edr	= 5,
187 		.irq_lines	= 2,
188 		.mask = { {
189 			.isr_offset	= REG_GPIO_ISR1A,
190 			.imr_offset	= REG_GPIO_IMR1A,
191 		}, {
192 			.isr_offset	= REG_GPIO_ISR1B,
193 			.imr_offset	= REG_GPIO_IMR1B,
194 		}, },
195 	},
196 	[1] = {
197 		.name		= "keypad",
198 		.set_cor	= true,
199 		SIH_INITIALIZER(KEYPAD_KEYP, 4)
200 	},
201 	[2] = {
202 		.name		= "bci",
203 		.module		= TWL5031_MODULE_INTERRUPTS,
204 		.control_offset	= TWL5031_INTERRUPTS_BCISIHCTRL,
205 		.bits		= 7,
206 		.bytes_ixr	= 1,
207 		.edr_offset	= TWL5031_INTERRUPTS_BCIEDR1,
208 		/* Note: most of these IRQs default to no-trigger */
209 		.bytes_edr	= 2,
210 		.irq_lines	= 2,
211 		.mask = { {
212 			.isr_offset	= TWL5031_INTERRUPTS_BCIISR1,
213 			.imr_offset	= TWL5031_INTERRUPTS_BCIIMR1,
214 		}, {
215 			.isr_offset	= TWL5031_INTERRUPTS_BCIISR2,
216 			.imr_offset	= TWL5031_INTERRUPTS_BCIIMR2,
217 		}, },
218 	},
219 	[3] = {
220 		.name		= "madc",
221 		SIH_INITIALIZER(MADC, 4)
222 	},
223 	[4] = {
224 		/* USB doesn't use the same SIH organization */
225 		.name		= "usb",
226 	},
227 	[5] = {
228 		.name		= "power",
229 		.set_cor	= true,
230 		SIH_INITIALIZER(INT_PWR, 8)
231 	},
232 	[6] = {
233 		/*
234 		 * ACI doesn't use the same SIH organization.
235 		 * For example, it supports only one interrupt line
236 		 */
237 		.name		= "aci",
238 		.module		= TWL5031_MODULE_ACCESSORY,
239 		.bits		= 9,
240 		.bytes_ixr	= 2,
241 		.irq_lines	= 1,
242 		.mask = { {
243 			.isr_offset	= TWL5031_ACIIDR_LSB,
244 			.imr_offset	= TWL5031_ACIIMR_LSB,
245 		}, },
246 
247 	},
248 	[7] = {
249 		/* Accessory */
250 		.name		= "acc",
251 		.module		= TWL5031_MODULE_ACCESSORY,
252 		.control_offset	= TWL5031_ACCSIHCTRL,
253 		.bits		= 2,
254 		.bytes_ixr	= 1,
255 		.edr_offset	= TWL5031_ACCEDR1,
256 		/* Note: most of these IRQs default to no-trigger */
257 		.bytes_edr	= 1,
258 		.irq_lines	= 2,
259 		.mask = { {
260 			.isr_offset	= TWL5031_ACCISR1,
261 			.imr_offset	= TWL5031_ACCIMR1,
262 		}, {
263 			.isr_offset	= TWL5031_ACCISR2,
264 			.imr_offset	= TWL5031_ACCIMR2,
265 		}, },
266 	},
267 };
268 
269 #undef TWL4030_MODULE_KEYPAD_KEYP
270 #undef TWL4030_MODULE_INT_PWR
271 #undef TWL4030_INT_PWR_EDR
272 
273 /*----------------------------------------------------------------------*/
274 
275 static unsigned twl4030_irq_base;
276 
277 static struct completion irq_event;
278 
279 /*
280  * This thread processes interrupts reported by the Primary Interrupt Handler.
281  */
282 static int twl4030_irq_thread(void *data)
283 {
284 	long irq = (long)data;
285 	static unsigned i2c_errors;
286 	static const unsigned max_i2c_errors = 100;
287 
288 
289 	current->flags |= PF_NOFREEZE;
290 
291 	while (!kthread_should_stop()) {
292 		int ret;
293 		int module_irq;
294 		u8 pih_isr;
295 
296 		/* Wait for IRQ, then read PIH irq status (also blocking) */
297 		wait_for_completion_interruptible(&irq_event);
298 
299 		ret = twl_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr,
300 					  REG_PIH_ISR_P1);
301 		if (ret) {
302 			pr_warning("twl4030: I2C error %d reading PIH ISR\n",
303 					ret);
304 			if (++i2c_errors >= max_i2c_errors) {
305 				printk(KERN_ERR "Maximum I2C error count"
306 						" exceeded.  Terminating %s.\n",
307 						__func__);
308 				break;
309 			}
310 			complete(&irq_event);
311 			continue;
312 		}
313 
314 		/* these handlers deal with the relevant SIH irq status */
315 		local_irq_disable();
316 		for (module_irq = twl4030_irq_base;
317 				pih_isr;
318 				pih_isr >>= 1, module_irq++) {
319 			if (pih_isr & 0x1) {
320 				struct irq_desc *d = irq_to_desc(module_irq);
321 
322 				if (!d) {
323 					pr_err("twl4030: Invalid SIH IRQ: %d\n",
324 					       module_irq);
325 					return -EINVAL;
326 				}
327 
328 				/* These can't be masked ... always warn
329 				 * if we get any surprises.
330 				 */
331 				if (d->status & IRQ_DISABLED)
332 					note_interrupt(module_irq, d,
333 							IRQ_NONE);
334 				else
335 					d->handle_irq(module_irq, d);
336 			}
337 		}
338 		local_irq_enable();
339 
340 		enable_irq(irq);
341 	}
342 
343 	return 0;
344 }
345 
346 /*
347  * handle_twl4030_pih() is the desc->handle method for the twl4030 interrupt.
348  * This is a chained interrupt, so there is no desc->action method for it.
349  * Now we need to query the interrupt controller in the twl4030 to determine
350  * which module is generating the interrupt request.  However, we can't do i2c
351  * transactions in interrupt context, so we must defer that work to a kernel
352  * thread.  All we do here is acknowledge and mask the interrupt and wakeup
353  * the kernel thread.
354  */
355 static irqreturn_t handle_twl4030_pih(int irq, void *devid)
356 {
357 	/* Acknowledge, clear *AND* mask the interrupt... */
358 	disable_irq_nosync(irq);
359 	complete(devid);
360 	return IRQ_HANDLED;
361 }
362 /*----------------------------------------------------------------------*/
363 
364 /*
365  * twl4030_init_sih_modules() ... start from a known state where no
366  * IRQs will be coming in, and where we can quickly enable them then
367  * handle them as they arrive.  Mask all IRQs: maybe init SIH_CTRL.
368  *
369  * NOTE:  we don't touch EDR registers here; they stay with hardware
370  * defaults or whatever the last value was.  Note that when both EDR
371  * bits for an IRQ are clear, that's as if its IMR bit is set...
372  */
373 static int twl4030_init_sih_modules(unsigned line)
374 {
375 	const struct sih *sih;
376 	u8 buf[4];
377 	int i;
378 	int status;
379 
380 	/* line 0 == int1_n signal; line 1 == int2_n signal */
381 	if (line > 1)
382 		return -EINVAL;
383 
384 	irq_line = line;
385 
386 	/* disable all interrupts on our line */
387 	memset(buf, 0xff, sizeof buf);
388 	sih = sih_modules;
389 	for (i = 0; i < nr_sih_modules; i++, sih++) {
390 
391 		/* skip USB -- it's funky */
392 		if (!sih->bytes_ixr)
393 			continue;
394 
395 		/* Not all the SIH modules support multiple interrupt lines */
396 		if (sih->irq_lines <= line)
397 			continue;
398 
399 		status = twl_i2c_write(sih->module, buf,
400 				sih->mask[line].imr_offset, sih->bytes_ixr);
401 		if (status < 0)
402 			pr_err("twl4030: err %d initializing %s %s\n",
403 					status, sih->name, "IMR");
404 
405 		/* Maybe disable "exclusive" mode; buffer second pending irq;
406 		 * set Clear-On-Read (COR) bit.
407 		 *
408 		 * NOTE that sometimes COR polarity is documented as being
409 		 * inverted:  for MADC and BCI, COR=1 means "clear on write".
410 		 * And for PWR_INT it's not documented...
411 		 */
412 		if (sih->set_cor) {
413 			status = twl_i2c_write_u8(sih->module,
414 					TWL4030_SIH_CTRL_COR_MASK,
415 					sih->control_offset);
416 			if (status < 0)
417 				pr_err("twl4030: err %d initializing %s %s\n",
418 						status, sih->name, "SIH_CTRL");
419 		}
420 	}
421 
422 	sih = sih_modules;
423 	for (i = 0; i < nr_sih_modules; i++, sih++) {
424 		u8 rxbuf[4];
425 		int j;
426 
427 		/* skip USB */
428 		if (!sih->bytes_ixr)
429 			continue;
430 
431 		/* Not all the SIH modules support multiple interrupt lines */
432 		if (sih->irq_lines <= line)
433 			continue;
434 
435 		/* Clear pending interrupt status.  Either the read was
436 		 * enough, or we need to write those bits.  Repeat, in
437 		 * case an IRQ is pending (PENDDIS=0) ... that's not
438 		 * uncommon with PWR_INT.PWRON.
439 		 */
440 		for (j = 0; j < 2; j++) {
441 			status = twl_i2c_read(sih->module, rxbuf,
442 				sih->mask[line].isr_offset, sih->bytes_ixr);
443 			if (status < 0)
444 				pr_err("twl4030: err %d initializing %s %s\n",
445 					status, sih->name, "ISR");
446 
447 			if (!sih->set_cor)
448 				status = twl_i2c_write(sih->module, buf,
449 					sih->mask[line].isr_offset,
450 					sih->bytes_ixr);
451 			/* else COR=1 means read sufficed.
452 			 * (for most SIH modules...)
453 			 */
454 		}
455 	}
456 
457 	return 0;
458 }
459 
460 static inline void activate_irq(int irq)
461 {
462 #ifdef CONFIG_ARM
463 	/* ARM requires an extra step to clear IRQ_NOREQUEST, which it
464 	 * sets on behalf of every irq_chip.  Also sets IRQ_NOPROBE.
465 	 */
466 	set_irq_flags(irq, IRQF_VALID);
467 #else
468 	/* same effect on other architectures */
469 	set_irq_noprobe(irq);
470 #endif
471 }
472 
473 /*----------------------------------------------------------------------*/
474 
475 static DEFINE_SPINLOCK(sih_agent_lock);
476 
477 static struct workqueue_struct *wq;
478 
479 struct sih_agent {
480 	int			irq_base;
481 	const struct sih	*sih;
482 
483 	u32			imr;
484 	bool			imr_change_pending;
485 	struct work_struct	mask_work;
486 
487 	u32			edge_change;
488 	struct work_struct	edge_work;
489 };
490 
491 static void twl4030_sih_do_mask(struct work_struct *work)
492 {
493 	struct sih_agent	*agent;
494 	const struct sih	*sih;
495 	union {
496 		u8	bytes[4];
497 		u32	word;
498 	}			imr;
499 	int			status;
500 
501 	agent = container_of(work, struct sih_agent, mask_work);
502 
503 	/* see what work we have */
504 	spin_lock_irq(&sih_agent_lock);
505 	if (agent->imr_change_pending) {
506 		sih = agent->sih;
507 		/* byte[0] gets overwritten as we write ... */
508 		imr.word = cpu_to_le32(agent->imr << 8);
509 		agent->imr_change_pending = false;
510 	} else
511 		sih = NULL;
512 	spin_unlock_irq(&sih_agent_lock);
513 	if (!sih)
514 		return;
515 
516 	/* write the whole mask ... simpler than subsetting it */
517 	status = twl_i2c_write(sih->module, imr.bytes,
518 			sih->mask[irq_line].imr_offset, sih->bytes_ixr);
519 	if (status)
520 		pr_err("twl4030: %s, %s --> %d\n", __func__,
521 				"write", status);
522 }
523 
524 static void twl4030_sih_do_edge(struct work_struct *work)
525 {
526 	struct sih_agent	*agent;
527 	const struct sih	*sih;
528 	u8			bytes[6];
529 	u32			edge_change;
530 	int			status;
531 
532 	agent = container_of(work, struct sih_agent, edge_work);
533 
534 	/* see what work we have */
535 	spin_lock_irq(&sih_agent_lock);
536 	edge_change = agent->edge_change;
537 	agent->edge_change = 0;
538 	sih = edge_change ? agent->sih : NULL;
539 	spin_unlock_irq(&sih_agent_lock);
540 	if (!sih)
541 		return;
542 
543 	/* Read, reserving first byte for write scratch.  Yes, this
544 	 * could be cached for some speedup ... but be careful about
545 	 * any processor on the other IRQ line, EDR registers are
546 	 * shared.
547 	 */
548 	status = twl_i2c_read(sih->module, bytes + 1,
549 			sih->edr_offset, sih->bytes_edr);
550 	if (status) {
551 		pr_err("twl4030: %s, %s --> %d\n", __func__,
552 				"read", status);
553 		return;
554 	}
555 
556 	/* Modify only the bits we know must change */
557 	while (edge_change) {
558 		int		i = fls(edge_change) - 1;
559 		struct irq_desc	*d = irq_to_desc(i + agent->irq_base);
560 		int		byte = 1 + (i >> 2);
561 		int		off = (i & 0x3) * 2;
562 
563 		if (!d) {
564 			pr_err("twl4030: Invalid IRQ: %d\n",
565 			       i + agent->irq_base);
566 			return;
567 		}
568 
569 		bytes[byte] &= ~(0x03 << off);
570 
571 		raw_spin_lock_irq(&d->lock);
572 		if (d->status & IRQ_TYPE_EDGE_RISING)
573 			bytes[byte] |= BIT(off + 1);
574 		if (d->status & IRQ_TYPE_EDGE_FALLING)
575 			bytes[byte] |= BIT(off + 0);
576 		raw_spin_unlock_irq(&d->lock);
577 
578 		edge_change &= ~BIT(i);
579 	}
580 
581 	/* Write */
582 	status = twl_i2c_write(sih->module, bytes,
583 			sih->edr_offset, sih->bytes_edr);
584 	if (status)
585 		pr_err("twl4030: %s, %s --> %d\n", __func__,
586 				"write", status);
587 }
588 
589 /*----------------------------------------------------------------------*/
590 
591 /*
592  * All irq_chip methods get issued from code holding irq_desc[irq].lock,
593  * which can't perform the underlying I2C operations (because they sleep).
594  * So we must hand them off to a thread (workqueue) and cope with asynch
595  * completion, potentially including some re-ordering, of these requests.
596  */
597 
598 static void twl4030_sih_mask(unsigned irq)
599 {
600 	struct sih_agent *sih = get_irq_chip_data(irq);
601 	unsigned long flags;
602 
603 	spin_lock_irqsave(&sih_agent_lock, flags);
604 	sih->imr |= BIT(irq - sih->irq_base);
605 	sih->imr_change_pending = true;
606 	queue_work(wq, &sih->mask_work);
607 	spin_unlock_irqrestore(&sih_agent_lock, flags);
608 }
609 
610 static void twl4030_sih_unmask(unsigned irq)
611 {
612 	struct sih_agent *sih = get_irq_chip_data(irq);
613 	unsigned long flags;
614 
615 	spin_lock_irqsave(&sih_agent_lock, flags);
616 	sih->imr &= ~BIT(irq - sih->irq_base);
617 	sih->imr_change_pending = true;
618 	queue_work(wq, &sih->mask_work);
619 	spin_unlock_irqrestore(&sih_agent_lock, flags);
620 }
621 
622 static int twl4030_sih_set_type(unsigned irq, unsigned trigger)
623 {
624 	struct sih_agent *sih = get_irq_chip_data(irq);
625 	struct irq_desc *desc = irq_to_desc(irq);
626 	unsigned long flags;
627 
628 	if (!desc) {
629 		pr_err("twl4030: Invalid IRQ: %d\n", irq);
630 		return -EINVAL;
631 	}
632 
633 	if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
634 		return -EINVAL;
635 
636 	spin_lock_irqsave(&sih_agent_lock, flags);
637 	if ((desc->status & IRQ_TYPE_SENSE_MASK) != trigger) {
638 		desc->status &= ~IRQ_TYPE_SENSE_MASK;
639 		desc->status |= trigger;
640 		sih->edge_change |= BIT(irq - sih->irq_base);
641 		queue_work(wq, &sih->edge_work);
642 	}
643 	spin_unlock_irqrestore(&sih_agent_lock, flags);
644 	return 0;
645 }
646 
647 static struct irq_chip twl4030_sih_irq_chip = {
648 	.name		= "twl4030",
649 	.mask		= twl4030_sih_mask,
650 	.unmask		= twl4030_sih_unmask,
651 	.set_type	= twl4030_sih_set_type,
652 };
653 
654 /*----------------------------------------------------------------------*/
655 
656 static inline int sih_read_isr(const struct sih *sih)
657 {
658 	int status;
659 	union {
660 		u8 bytes[4];
661 		u32 word;
662 	} isr;
663 
664 	/* FIXME need retry-on-error ... */
665 
666 	isr.word = 0;
667 	status = twl_i2c_read(sih->module, isr.bytes,
668 			sih->mask[irq_line].isr_offset, sih->bytes_ixr);
669 
670 	return (status < 0) ? status : le32_to_cpu(isr.word);
671 }
672 
673 /*
674  * Generic handler for SIH interrupts ... we "know" this is called
675  * in task context, with IRQs enabled.
676  */
677 static void handle_twl4030_sih(unsigned irq, struct irq_desc *desc)
678 {
679 	struct sih_agent *agent = get_irq_data(irq);
680 	const struct sih *sih = agent->sih;
681 	int isr;
682 
683 	/* reading ISR acks the IRQs, using clear-on-read mode */
684 	local_irq_enable();
685 	isr = sih_read_isr(sih);
686 	local_irq_disable();
687 
688 	if (isr < 0) {
689 		pr_err("twl4030: %s SIH, read ISR error %d\n",
690 			sih->name, isr);
691 		/* REVISIT:  recover; eventually mask it all, etc */
692 		return;
693 	}
694 
695 	while (isr) {
696 		irq = fls(isr);
697 		irq--;
698 		isr &= ~BIT(irq);
699 
700 		if (irq < sih->bits)
701 			generic_handle_irq(agent->irq_base + irq);
702 		else
703 			pr_err("twl4030: %s SIH, invalid ISR bit %d\n",
704 				sih->name, irq);
705 	}
706 }
707 
708 static unsigned twl4030_irq_next;
709 
710 /* returns the first IRQ used by this SIH bank,
711  * or negative errno
712  */
713 int twl4030_sih_setup(int module)
714 {
715 	int			sih_mod;
716 	const struct sih	*sih = NULL;
717 	struct sih_agent	*agent;
718 	int			i, irq;
719 	int			status = -EINVAL;
720 	unsigned		irq_base = twl4030_irq_next;
721 
722 	/* only support modules with standard clear-on-read for now */
723 	for (sih_mod = 0, sih = sih_modules;
724 			sih_mod < nr_sih_modules;
725 			sih_mod++, sih++) {
726 		if (sih->module == module && sih->set_cor) {
727 			if (!WARN((irq_base + sih->bits) > NR_IRQS,
728 					"irq %d for %s too big\n",
729 					irq_base + sih->bits,
730 					sih->name))
731 				status = 0;
732 			break;
733 		}
734 	}
735 	if (status < 0)
736 		return status;
737 
738 	agent = kzalloc(sizeof *agent, GFP_KERNEL);
739 	if (!agent)
740 		return -ENOMEM;
741 
742 	status = 0;
743 
744 	agent->irq_base = irq_base;
745 	agent->sih = sih;
746 	agent->imr = ~0;
747 	INIT_WORK(&agent->mask_work, twl4030_sih_do_mask);
748 	INIT_WORK(&agent->edge_work, twl4030_sih_do_edge);
749 
750 	for (i = 0; i < sih->bits; i++) {
751 		irq = irq_base + i;
752 
753 		set_irq_chip_and_handler(irq, &twl4030_sih_irq_chip,
754 				handle_edge_irq);
755 		set_irq_chip_data(irq, agent);
756 		activate_irq(irq);
757 	}
758 
759 	status = irq_base;
760 	twl4030_irq_next += i;
761 
762 	/* replace generic PIH handler (handle_simple_irq) */
763 	irq = sih_mod + twl4030_irq_base;
764 	set_irq_data(irq, agent);
765 	set_irq_chained_handler(irq, handle_twl4030_sih);
766 
767 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", sih->name,
768 			irq, irq_base, twl4030_irq_next - 1);
769 
770 	return status;
771 }
772 
773 /* FIXME need a call to reverse twl4030_sih_setup() ... */
774 
775 
776 /*----------------------------------------------------------------------*/
777 
778 /* FIXME pass in which interrupt line we'll use ... */
779 #define twl_irq_line	0
780 
781 int twl4030_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
782 {
783 	static struct irq_chip	twl4030_irq_chip;
784 
785 	int			status;
786 	int			i;
787 	struct task_struct	*task;
788 
789 	/*
790 	 * Mask and clear all TWL4030 interrupts since initially we do
791 	 * not have any TWL4030 module interrupt handlers present
792 	 */
793 	status = twl4030_init_sih_modules(twl_irq_line);
794 	if (status < 0)
795 		return status;
796 
797 	wq = create_singlethread_workqueue("twl4030-irqchip");
798 	if (!wq) {
799 		pr_err("twl4030: workqueue FAIL\n");
800 		return -ESRCH;
801 	}
802 
803 	twl4030_irq_base = irq_base;
804 
805 	/* install an irq handler for each of the SIH modules;
806 	 * clone dummy irq_chip since PIH can't *do* anything
807 	 */
808 	twl4030_irq_chip = dummy_irq_chip;
809 	twl4030_irq_chip.name = "twl4030";
810 
811 	twl4030_sih_irq_chip.ack = dummy_irq_chip.ack;
812 
813 	for (i = irq_base; i < irq_end; i++) {
814 		set_irq_chip_and_handler(i, &twl4030_irq_chip,
815 				handle_simple_irq);
816 		activate_irq(i);
817 	}
818 	twl4030_irq_next = i;
819 	pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", "PIH",
820 			irq_num, irq_base, twl4030_irq_next - 1);
821 
822 	/* ... and the PWR_INT module ... */
823 	status = twl4030_sih_setup(TWL4030_MODULE_INT);
824 	if (status < 0) {
825 		pr_err("twl4030: sih_setup PWR INT --> %d\n", status);
826 		goto fail;
827 	}
828 
829 	/* install an irq handler to demultiplex the TWL4030 interrupt */
830 
831 
832 	init_completion(&irq_event);
833 
834 	status = request_irq(irq_num, handle_twl4030_pih, IRQF_DISABLED,
835 				"TWL4030-PIH", &irq_event);
836 	if (status < 0) {
837 		pr_err("twl4030: could not claim irq%d: %d\n", irq_num, status);
838 		goto fail_rqirq;
839 	}
840 
841 	task = kthread_run(twl4030_irq_thread, (void *)(long)irq_num,
842 								"twl4030-irq");
843 	if (IS_ERR(task)) {
844 		pr_err("twl4030: could not create irq %d thread!\n", irq_num);
845 		status = PTR_ERR(task);
846 		goto fail_kthread;
847 	}
848 	return status;
849 fail_kthread:
850 	free_irq(irq_num, &irq_event);
851 fail_rqirq:
852 	/* clean up twl4030_sih_setup */
853 fail:
854 	for (i = irq_base; i < irq_end; i++)
855 		set_irq_chip_and_handler(i, NULL, NULL);
856 	destroy_workqueue(wq);
857 	wq = NULL;
858 	return status;
859 }
860 
861 int twl4030_exit_irq(void)
862 {
863 	/* FIXME undo twl_init_irq() */
864 	if (twl4030_irq_base) {
865 		pr_err("twl4030: can't yet clean up IRQs?\n");
866 		return -ENOSYS;
867 	}
868 	return 0;
869 }
870 
871 int twl4030_init_chip_irq(const char *chip)
872 {
873 	if (!strcmp(chip, "twl5031")) {
874 		sih_modules = sih_modules_twl5031;
875 		nr_sih_modules = ARRAY_SIZE(sih_modules_twl5031);
876 	} else {
877 		sih_modules = sih_modules_twl4030;
878 		nr_sih_modules = ARRAY_SIZE(sih_modules_twl4030);
879 	}
880 
881 	return 0;
882 }
883