2 * twl4030-irq.c - TWL4030/TPS659x0 irq support
4 * Copyright (C) 2005-2006 Texas Instruments, Inc.
6 * Modifications to defer interrupt handling to a kernel thread:
7 * Copyright (C) 2006 MontaVista Software, Inc.
9 * Based on tlv320aic23.c:
10 * Copyright (c) by Kai Svahn <kai.svahn@nokia.com>
12 * Code cleanup and modifications to IRQ handler.
13 * by syed khasim <x0khasim@ti.com>
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.
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.
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
30 #include <linux/init.h>
31 #include <linux/interrupt.h>
32 #include <linux/irq.h>
33 #include <linux/kthread.h>
35 #include <linux/i2c/twl4030.h>
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.
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.
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
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 */
62 /* Linux could (eventually) use either IRQ line */
67 u8 module
; /* module id */
68 u8 control_offset
; /* for SIH_CTRL */
71 u8 bits
; /* valid in isr/imr */
72 u8 bytes_ixr
; /* bytelen of ISR/IMR/SIR */
75 u8 bytes_edr
; /* bytelen of EDR */
77 /* SIR ignored -- set interrupt, for testing only */
82 /* + 2 bytes padding */
85 #define SIH_INITIALIZER(modname, nbits) \
86 .module = TWL4030_MODULE_ ## modname, \
87 .control_offset = TWL4030_ ## modname ## _SIH_CTRL, \
89 .bytes_ixr = DIV_ROUND_UP(nbits, 8), \
90 .edr_offset = TWL4030_ ## modname ## _EDR, \
91 .bytes_edr = DIV_ROUND_UP((2*(nbits)), 8), \
93 .isr_offset = TWL4030_ ## modname ## _ISR1, \
94 .imr_offset = TWL4030_ ## modname ## _IMR1, \
97 .isr_offset = TWL4030_ ## modname ## _ISR2, \
98 .imr_offset = TWL4030_ ## modname ## _IMR2, \
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
107 /* Order in this table matches order in PIH_ISR. That is,
108 * BIT(n) in PIH_ISR is sih_modules[n].
110 static const struct sih sih_modules
[6] = {
113 .module
= TWL4030_MODULE_GPIO
,
114 .control_offset
= REG_GPIO_SIH_CTRL
,
116 .bits
= TWL4030_GPIO_MAX
,
118 /* Note: *all* of these IRQs default to no-trigger */
119 .edr_offset
= REG_GPIO_EDR1
,
122 .isr_offset
= REG_GPIO_ISR1A
,
123 .imr_offset
= REG_GPIO_IMR1A
,
125 .isr_offset
= REG_GPIO_ISR1B
,
126 .imr_offset
= REG_GPIO_IMR1B
,
132 SIH_INITIALIZER(KEYPAD_KEYP
, 4)
136 .module
= TWL4030_MODULE_INTERRUPTS
,
137 .control_offset
= TWL4030_INTERRUPTS_BCISIHCTRL
,
140 .edr_offset
= TWL4030_INTERRUPTS_BCIEDR1
,
141 /* Note: most of these IRQs default to no-trigger */
144 .isr_offset
= TWL4030_INTERRUPTS_BCIISR1A
,
145 .imr_offset
= TWL4030_INTERRUPTS_BCIIMR1A
,
147 .isr_offset
= TWL4030_INTERRUPTS_BCIISR1B
,
148 .imr_offset
= TWL4030_INTERRUPTS_BCIIMR1B
,
153 SIH_INITIALIZER(MADC
, 4)
156 /* USB doesn't use the same SIH organization */
162 SIH_INITIALIZER(INT_PWR
, 8)
164 /* there are no SIH modules #6 or #7 ... */
167 #undef TWL4030_MODULE_KEYPAD_KEYP
168 #undef TWL4030_MODULE_INT_PWR
169 #undef TWL4030_INT_PWR_EDR
171 /*----------------------------------------------------------------------*/
173 static unsigned twl4030_irq_base
;
175 static struct completion irq_event
;
178 * This thread processes interrupts reported by the Primary Interrupt Handler.
180 static int twl4030_irq_thread(void *data
)
182 long irq
= (long)data
;
183 static unsigned i2c_errors
;
184 static const unsigned max_i2c_errors
= 100;
187 current
->flags
|= PF_NOFREEZE
;
189 while (!kthread_should_stop()) {
194 /* Wait for IRQ, then read PIH irq status (also blocking) */
195 wait_for_completion_interruptible(&irq_event
);
197 ret
= twl4030_i2c_read_u8(TWL4030_MODULE_PIH
, &pih_isr
,
200 pr_warning("twl4030: I2C error %d reading PIH ISR\n",
202 if (++i2c_errors
>= max_i2c_errors
) {
203 printk(KERN_ERR
"Maximum I2C error count"
204 " exceeded. Terminating %s.\n",
208 complete(&irq_event
);
212 /* these handlers deal with the relevant SIH irq status */
214 for (module_irq
= twl4030_irq_base
;
216 pih_isr
>>= 1, module_irq
++) {
218 struct irq_desc
*d
= irq_to_desc(module_irq
);
221 pr_err("twl4030: Invalid SIH IRQ: %d\n",
226 /* These can't be masked ... always warn
227 * if we get any surprises.
229 if (d
->status
& IRQ_DISABLED
)
230 note_interrupt(module_irq
, d
,
233 d
->handle_irq(module_irq
, d
);
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
253 static irqreturn_t
handle_twl4030_pih(int irq
, void *devid
)
255 /* Acknowledge, clear *AND* mask the interrupt... */
256 disable_irq_nosync(irq
);
260 /*----------------------------------------------------------------------*/
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.
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...
271 static int twl4030_init_sih_modules(unsigned line
)
273 const struct sih
*sih
;
278 /* line 0 == int1_n signal; line 1 == int2_n signal */
284 /* disable all interrupts on our line */
285 memset(buf
, 0xff, sizeof buf
);
287 for (i
= 0; i
< ARRAY_SIZE(sih_modules
); i
++, sih
++) {
289 /* skip USB -- it's funky */
293 status
= twl4030_i2c_write(sih
->module
, buf
,
294 sih
->mask
[line
].imr_offset
, sih
->bytes_ixr
);
296 pr_err("twl4030: err %d initializing %s %s\n",
297 status
, sih
->name
, "IMR");
299 /* Maybe disable "exclusive" mode; buffer second pending irq;
300 * set Clear-On-Read (COR) bit.
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...
307 status
= twl4030_i2c_write_u8(sih
->module
,
308 TWL4030_SIH_CTRL_COR_MASK
,
309 sih
->control_offset
);
311 pr_err("twl4030: err %d initializing %s %s\n",
312 status
, sih
->name
, "SIH_CTRL");
317 for (i
= 0; i
< ARRAY_SIZE(sih_modules
); i
++, sih
++) {
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.
330 for (j
= 0; j
< 2; j
++) {
331 status
= twl4030_i2c_read(sih
->module
, rxbuf
,
332 sih
->mask
[line
].isr_offset
, sih
->bytes_ixr
);
334 pr_err("twl4030: err %d initializing %s %s\n",
335 status
, sih
->name
, "ISR");
338 status
= twl4030_i2c_write(sih
->module
, buf
,
339 sih
->mask
[line
].isr_offset
,
341 /* else COR=1 means read sufficed.
342 * (for most SIH modules...)
350 static inline void activate_irq(int irq
)
353 /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
354 * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE.
356 set_irq_flags(irq
, IRQF_VALID
);
358 /* same effect on other architectures */
359 set_irq_noprobe(irq
);
363 /*----------------------------------------------------------------------*/
365 static DEFINE_SPINLOCK(sih_agent_lock
);
367 static struct workqueue_struct
*wq
;
371 const struct sih
*sih
;
374 bool imr_change_pending
;
375 struct work_struct mask_work
;
378 struct work_struct edge_work
;
381 static void twl4030_sih_do_mask(struct work_struct
*work
)
383 struct sih_agent
*agent
;
384 const struct sih
*sih
;
391 agent
= container_of(work
, struct sih_agent
, mask_work
);
393 /* see what work we have */
394 spin_lock_irq(&sih_agent_lock
);
395 if (agent
->imr_change_pending
) {
397 /* byte[0] gets overwritten as we write ... */
398 imr
.word
= cpu_to_le32(agent
->imr
<< 8);
399 agent
->imr_change_pending
= false;
402 spin_unlock_irq(&sih_agent_lock
);
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
);
410 pr_err("twl4030: %s, %s --> %d\n", __func__
,
414 static void twl4030_sih_do_edge(struct work_struct
*work
)
416 struct sih_agent
*agent
;
417 const struct sih
*sih
;
422 agent
= container_of(work
, struct sih_agent
, edge_work
);
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
);
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
438 status
= twl4030_i2c_read(sih
->module
, bytes
+ 1,
439 sih
->edr_offset
, sih
->bytes_edr
);
441 pr_err("twl4030: %s, %s --> %d\n", __func__
,
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;
454 pr_err("twl4030: Invalid IRQ: %d\n",
455 i
+ agent
->irq_base
);
459 bytes
[byte
] &= ~(0x03 << off
);
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
);
468 edge_change
&= ~BIT(i
);
472 status
= twl4030_i2c_write(sih
->module
, bytes
,
473 sih
->edr_offset
, sih
->bytes_edr
);
475 pr_err("twl4030: %s, %s --> %d\n", __func__
,
479 /*----------------------------------------------------------------------*/
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.
488 static void twl4030_sih_mask(unsigned irq
)
490 struct sih_agent
*sih
= get_irq_chip_data(irq
);
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
);
500 static void twl4030_sih_unmask(unsigned irq
)
502 struct sih_agent
*sih
= get_irq_chip_data(irq
);
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
);
512 static int twl4030_sih_set_type(unsigned irq
, unsigned trigger
)
514 struct sih_agent
*sih
= get_irq_chip_data(irq
);
515 struct irq_desc
*desc
= irq_to_desc(irq
);
519 pr_err("twl4030: Invalid IRQ: %d\n", irq
);
523 if (trigger
& ~(IRQ_TYPE_EDGE_FALLING
| IRQ_TYPE_EDGE_RISING
))
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
);
533 spin_unlock_irqrestore(&sih_agent_lock
, flags
);
537 static struct irq_chip twl4030_sih_irq_chip
= {
539 .mask
= twl4030_sih_mask
,
540 .unmask
= twl4030_sih_unmask
,
541 .set_type
= twl4030_sih_set_type
,
544 /*----------------------------------------------------------------------*/
546 static inline int sih_read_isr(const struct sih
*sih
)
554 /* FIXME need retry-on-error ... */
557 status
= twl4030_i2c_read(sih
->module
, isr
.bytes
,
558 sih
->mask
[irq_line
].isr_offset
, sih
->bytes_ixr
);
560 return (status
< 0) ? status
: le32_to_cpu(isr
.word
);
564 * Generic handler for SIH interrupts ... we "know" this is called
565 * in task context, with IRQs enabled.
567 static void handle_twl4030_sih(unsigned irq
, struct irq_desc
*desc
)
569 struct sih_agent
*agent
= get_irq_data(irq
);
570 const struct sih
*sih
= agent
->sih
;
573 /* reading ISR acks the IRQs, using clear-on-read mode */
575 isr
= sih_read_isr(sih
);
579 pr_err("twl4030: %s SIH, read ISR error %d\n",
581 /* REVISIT: recover; eventually mask it all, etc */
591 generic_handle_irq(agent
->irq_base
+ irq
);
593 pr_err("twl4030: %s SIH, invalid ISR bit %d\n",
598 static unsigned twl4030_irq_next
;
600 /* returns the first IRQ used by this SIH bank,
603 int twl4030_sih_setup(int module
)
606 const struct sih
*sih
= NULL
;
607 struct sih_agent
*agent
;
609 int status
= -EINVAL
;
610 unsigned irq_base
= twl4030_irq_next
;
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
);
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
,
628 agent
= kzalloc(sizeof *agent
, GFP_KERNEL
);
634 agent
->irq_base
= irq_base
;
637 INIT_WORK(&agent
->mask_work
, twl4030_sih_do_mask
);
638 INIT_WORK(&agent
->edge_work
, twl4030_sih_do_edge
);
640 for (i
= 0; i
< sih
->bits
; i
++) {
643 set_irq_chip_and_handler(irq
, &twl4030_sih_irq_chip
,
645 set_irq_chip_data(irq
, agent
);
650 twl4030_irq_next
+= i
;
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
);
657 pr_info("twl4030: %s (irq %d) chaining IRQs %d..%d\n", sih
->name
,
658 irq
, irq_base
, twl4030_irq_next
- 1);
663 /* FIXME need a call to reverse twl4030_sih_setup() ... */
666 /*----------------------------------------------------------------------*/
668 /* FIXME pass in which interrupt line we'll use ... */
669 #define twl_irq_line 0
671 int twl_init_irq(int irq_num
, unsigned irq_base
, unsigned irq_end
)
673 static struct irq_chip twl4030_irq_chip
;
677 struct task_struct
*task
;
680 * Mask and clear all TWL4030 interrupts since initially we do
681 * not have any TWL4030 module interrupt handlers present
683 status
= twl4030_init_sih_modules(twl_irq_line
);
687 wq
= create_singlethread_workqueue("twl4030-irqchip");
689 pr_err("twl4030: workqueue FAIL\n");
693 twl4030_irq_base
= irq_base
;
695 /* install an irq handler for each of the SIH modules;
696 * clone dummy irq_chip since PIH can't *do* anything
698 twl4030_irq_chip
= dummy_irq_chip
;
699 twl4030_irq_chip
.name
= "twl4030";
701 twl4030_sih_irq_chip
.ack
= dummy_irq_chip
.ack
;
703 for (i
= irq_base
; i
< irq_end
; i
++) {
704 set_irq_chip_and_handler(i
, &twl4030_irq_chip
,
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);
712 /* ... and the PWR_INT module ... */
713 status
= twl4030_sih_setup(TWL4030_MODULE_INT
);
715 pr_err("twl4030: sih_setup PWR INT --> %d\n", status
);
719 /* install an irq handler to demultiplex the TWL4030 interrupt */
722 init_completion(&irq_event
);
724 status
= request_irq(irq_num
, handle_twl4030_pih
, IRQF_DISABLED
,
725 "TWL4030-PIH", &irq_event
);
727 pr_err("twl4030: could not claim irq%d: %d\n", irq_num
, status
);
731 task
= kthread_run(twl4030_irq_thread
, (void *)irq_num
, "twl4030-irq");
733 pr_err("twl4030: could not create irq %d thread!\n", irq_num
);
734 status
= PTR_ERR(task
);
739 free_irq(irq_num
, &irq_event
);
741 /* clean up twl4030_sih_setup */
743 for (i
= irq_base
; i
< irq_end
; i
++)
744 set_irq_chip_and_handler(i
, NULL
, NULL
);
745 destroy_workqueue(wq
);
750 int twl_exit_irq(void)
752 /* FIXME undo twl_init_irq() */
753 if (twl4030_irq_base
) {
754 pr_err("twl4030: can't yet clean up IRQs?\n");