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1/*
2 * Renesas INTC External IRQ Pin Driver
3 *
4 * Copyright (C) 2013 Magnus Damm
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/clk.h>
21#include <linux/init.h>
22#include <linux/of.h>
23#include <linux/platform_device.h>
24#include <linux/spinlock.h>
25#include <linux/interrupt.h>
26#include <linux/ioport.h>
27#include <linux/io.h>
28#include <linux/irq.h>
29#include <linux/irqdomain.h>
30#include <linux/err.h>
31#include <linux/slab.h>
32#include <linux/module.h>
33#include <linux/of_device.h>
34#include <linux/pm_runtime.h>
35
36#define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
37
38#define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
39#define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
40#define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
41#define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
42#define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
43#define INTC_IRQPIN_REG_NR_MANDATORY 5
44#define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
45#define INTC_IRQPIN_REG_NR 6
46
47/* INTC external IRQ PIN hardware register access:
48 *
49 * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
50 * PRIO is read-write 32-bit with 4-bits per IRQ (**)
51 * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
52 * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
53 * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
54 *
55 * (*) May be accessed by more than one driver instance - lock needed
56 * (**) Read-modify-write access by one driver instance - lock needed
57 * (***) Accessed by one driver instance only - no locking needed
58 */
59
60struct intc_irqpin_iomem {
61 void __iomem *iomem;
62 unsigned long (*read)(void __iomem *iomem);
63 void (*write)(void __iomem *iomem, unsigned long data);
64 int width;
65};
66
67struct intc_irqpin_irq {
68 int hw_irq;
69 int requested_irq;
70 int domain_irq;
71 struct intc_irqpin_priv *p;
72};
73
74struct intc_irqpin_priv {
75 struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
76 struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
77 unsigned int sense_bitfield_width;
78 struct platform_device *pdev;
79 struct irq_chip irq_chip;
80 struct irq_domain *irq_domain;
81 struct clk *clk;
82 unsigned shared_irqs:1;
83 unsigned needs_clk:1;
84 u8 shared_irq_mask;
85};
86
87struct intc_irqpin_config {
88 unsigned int irlm_bit;
89 unsigned needs_irlm:1;
90 unsigned needs_clk:1;
91};
92
93static unsigned long intc_irqpin_read32(void __iomem *iomem)
94{
95 return ioread32(iomem);
96}
97
98static unsigned long intc_irqpin_read8(void __iomem *iomem)
99{
100 return ioread8(iomem);
101}
102
103static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
104{
105 iowrite32(data, iomem);
106}
107
108static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
109{
110 iowrite8(data, iomem);
111}
112
113static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
114 int reg)
115{
116 struct intc_irqpin_iomem *i = &p->iomem[reg];
117
118 return i->read(i->iomem);
119}
120
121static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
122 int reg, unsigned long data)
123{
124 struct intc_irqpin_iomem *i = &p->iomem[reg];
125
126 i->write(i->iomem, data);
127}
128
129static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
130 int reg, int hw_irq)
131{
132 return BIT((p->iomem[reg].width - 1) - hw_irq);
133}
134
135static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
136 int reg, int hw_irq)
137{
138 intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
139}
140
141static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
142
143static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
144 int reg, int shift,
145 int width, int value)
146{
147 unsigned long flags;
148 unsigned long tmp;
149
150 raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
151
152 tmp = intc_irqpin_read(p, reg);
153 tmp &= ~(((1 << width) - 1) << shift);
154 tmp |= value << shift;
155 intc_irqpin_write(p, reg, tmp);
156
157 raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
158}
159
160static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
161 int irq, int do_mask)
162{
163 /* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
164 int bitfield_width = 4;
165 int shift = 32 - (irq + 1) * bitfield_width;
166
167 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
168 shift, bitfield_width,
169 do_mask ? 0 : (1 << bitfield_width) - 1);
170}
171
172static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
173{
174 /* The SENSE register is assumed to be 32-bit. */
175 int bitfield_width = p->sense_bitfield_width;
176 int shift = 32 - (irq + 1) * bitfield_width;
177
178 dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
179
180 if (value >= (1 << bitfield_width))
181 return -EINVAL;
182
183 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
184 bitfield_width, value);
185 return 0;
186}
187
188static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
189{
190 dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
191 str, i->requested_irq, i->hw_irq, i->domain_irq);
192}
193
194static void intc_irqpin_irq_enable(struct irq_data *d)
195{
196 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
197 int hw_irq = irqd_to_hwirq(d);
198
199 intc_irqpin_dbg(&p->irq[hw_irq], "enable");
200 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
201}
202
203static void intc_irqpin_irq_disable(struct irq_data *d)
204{
205 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
206 int hw_irq = irqd_to_hwirq(d);
207
208 intc_irqpin_dbg(&p->irq[hw_irq], "disable");
209 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
210}
211
212static void intc_irqpin_shared_irq_enable(struct irq_data *d)
213{
214 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
215 int hw_irq = irqd_to_hwirq(d);
216
217 intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
218 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
219
220 p->shared_irq_mask &= ~BIT(hw_irq);
221}
222
223static void intc_irqpin_shared_irq_disable(struct irq_data *d)
224{
225 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
226 int hw_irq = irqd_to_hwirq(d);
227
228 intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
229 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
230
231 p->shared_irq_mask |= BIT(hw_irq);
232}
233
234static void intc_irqpin_irq_enable_force(struct irq_data *d)
235{
236 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
237 int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
238
239 intc_irqpin_irq_enable(d);
240
241 /* enable interrupt through parent interrupt controller,
242 * assumes non-shared interrupt with 1:1 mapping
243 * needed for busted IRQs on some SoCs like sh73a0
244 */
245 irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
246}
247
248static void intc_irqpin_irq_disable_force(struct irq_data *d)
249{
250 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
251 int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
252
253 /* disable interrupt through parent interrupt controller,
254 * assumes non-shared interrupt with 1:1 mapping
255 * needed for busted IRQs on some SoCs like sh73a0
256 */
257 irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
258 intc_irqpin_irq_disable(d);
259}
260
261#define INTC_IRQ_SENSE_VALID 0x10
262#define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
263
264static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
265 [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
266 [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
267 [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
268 [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
269 [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
270};
271
272static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
273{
274 unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
275 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
276
277 if (!(value & INTC_IRQ_SENSE_VALID))
278 return -EINVAL;
279
280 return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
281 value ^ INTC_IRQ_SENSE_VALID);
282}
283
284static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
285{
286 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
287 int hw_irq = irqd_to_hwirq(d);
288
289 irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
290
291 if (!p->clk)
292 return 0;
293
294 if (on)
295 clk_enable(p->clk);
296 else
297 clk_disable(p->clk);
298
299 return 0;
300}
301
302static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
303{
304 struct intc_irqpin_irq *i = dev_id;
305 struct intc_irqpin_priv *p = i->p;
306 unsigned long bit;
307
308 intc_irqpin_dbg(i, "demux1");
309 bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
310
311 if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
312 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
313 intc_irqpin_dbg(i, "demux2");
314 generic_handle_irq(i->domain_irq);
315 return IRQ_HANDLED;
316 }
317 return IRQ_NONE;
318}
319
320static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
321{
322 struct intc_irqpin_priv *p = dev_id;
323 unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
324 irqreturn_t status = IRQ_NONE;
325 int k;
326
327 for (k = 0; k < 8; k++) {
328 if (reg_source & BIT(7 - k)) {
329 if (BIT(k) & p->shared_irq_mask)
330 continue;
331
332 status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
333 }
334 }
335
336 return status;
337}
338
339/*
340 * This lock class tells lockdep that INTC External IRQ Pin irqs are in a
341 * different category than their parents, so it won't report false recursion.
342 */
343static struct lock_class_key intc_irqpin_irq_lock_class;
344
345static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
346 irq_hw_number_t hw)
347{
348 struct intc_irqpin_priv *p = h->host_data;
349
350 p->irq[hw].domain_irq = virq;
351 p->irq[hw].hw_irq = hw;
352
353 intc_irqpin_dbg(&p->irq[hw], "map");
354 irq_set_chip_data(virq, h->host_data);
355 irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class);
356 irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
357 return 0;
358}
359
360static const struct irq_domain_ops intc_irqpin_irq_domain_ops = {
361 .map = intc_irqpin_irq_domain_map,
362 .xlate = irq_domain_xlate_twocell,
363};
364
365static const struct intc_irqpin_config intc_irqpin_irlm_r8a777x = {
366 .irlm_bit = 23, /* ICR0.IRLM0 */
367 .needs_irlm = 1,
368 .needs_clk = 0,
369};
370
371static const struct intc_irqpin_config intc_irqpin_rmobile = {
372 .needs_irlm = 0,
373 .needs_clk = 1,
374};
375
376static const struct of_device_id intc_irqpin_dt_ids[] = {
377 { .compatible = "renesas,intc-irqpin", },
378 { .compatible = "renesas,intc-irqpin-r8a7778",
379 .data = &intc_irqpin_irlm_r8a777x },
380 { .compatible = "renesas,intc-irqpin-r8a7779",
381 .data = &intc_irqpin_irlm_r8a777x },
382 { .compatible = "renesas,intc-irqpin-r8a7740",
383 .data = &intc_irqpin_rmobile },
384 { .compatible = "renesas,intc-irqpin-sh73a0",
385 .data = &intc_irqpin_rmobile },
386 {},
387};
388MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
389
390static int intc_irqpin_probe(struct platform_device *pdev)
391{
392 const struct intc_irqpin_config *config = NULL;
393 struct device *dev = &pdev->dev;
394 const struct of_device_id *of_id;
395 struct intc_irqpin_priv *p;
396 struct intc_irqpin_iomem *i;
397 struct resource *io[INTC_IRQPIN_REG_NR];
398 struct resource *irq;
399 struct irq_chip *irq_chip;
400 void (*enable_fn)(struct irq_data *d);
401 void (*disable_fn)(struct irq_data *d);
402 const char *name = dev_name(dev);
403 bool control_parent;
404 unsigned int nirqs;
405 int ref_irq;
406 int ret;
407 int k;
408
409 p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
410 if (!p) {
411 dev_err(dev, "failed to allocate driver data\n");
412 return -ENOMEM;
413 }
414
415 /* deal with driver instance configuration */
416 of_property_read_u32(dev->of_node, "sense-bitfield-width",
417 &p->sense_bitfield_width);
418 control_parent = of_property_read_bool(dev->of_node, "control-parent");
419 if (!p->sense_bitfield_width)
420 p->sense_bitfield_width = 4; /* default to 4 bits */
421
422 p->pdev = pdev;
423 platform_set_drvdata(pdev, p);
424
425 of_id = of_match_device(intc_irqpin_dt_ids, dev);
426 if (of_id && of_id->data) {
427 config = of_id->data;
428 p->needs_clk = config->needs_clk;
429 }
430
431 p->clk = devm_clk_get(dev, NULL);
432 if (IS_ERR(p->clk)) {
433 if (p->needs_clk) {
434 dev_err(dev, "unable to get clock\n");
435 ret = PTR_ERR(p->clk);
436 goto err0;
437 }
438 p->clk = NULL;
439 }
440
441 pm_runtime_enable(dev);
442 pm_runtime_get_sync(dev);
443
444 /* get hold of register banks */
445 memset(io, 0, sizeof(io));
446 for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
447 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
448 if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
449 dev_err(dev, "not enough IOMEM resources\n");
450 ret = -EINVAL;
451 goto err0;
452 }
453 }
454
455 /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
456 for (k = 0; k < INTC_IRQPIN_MAX; k++) {
457 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
458 if (!irq)
459 break;
460
461 p->irq[k].p = p;
462 p->irq[k].requested_irq = irq->start;
463 }
464
465 nirqs = k;
466 if (nirqs < 1) {
467 dev_err(dev, "not enough IRQ resources\n");
468 ret = -EINVAL;
469 goto err0;
470 }
471
472 /* ioremap IOMEM and setup read/write callbacks */
473 for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
474 i = &p->iomem[k];
475
476 /* handle optional registers */
477 if (!io[k])
478 continue;
479
480 switch (resource_size(io[k])) {
481 case 1:
482 i->width = 8;
483 i->read = intc_irqpin_read8;
484 i->write = intc_irqpin_write8;
485 break;
486 case 4:
487 i->width = 32;
488 i->read = intc_irqpin_read32;
489 i->write = intc_irqpin_write32;
490 break;
491 default:
492 dev_err(dev, "IOMEM size mismatch\n");
493 ret = -EINVAL;
494 goto err0;
495 }
496
497 i->iomem = devm_ioremap_nocache(dev, io[k]->start,
498 resource_size(io[k]));
499 if (!i->iomem) {
500 dev_err(dev, "failed to remap IOMEM\n");
501 ret = -ENXIO;
502 goto err0;
503 }
504 }
505
506 /* configure "individual IRQ mode" where needed */
507 if (config && config->needs_irlm) {
508 if (io[INTC_IRQPIN_REG_IRLM])
509 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
510 config->irlm_bit, 1, 1);
511 else
512 dev_warn(dev, "unable to select IRLM mode\n");
513 }
514
515 /* mask all interrupts using priority */
516 for (k = 0; k < nirqs; k++)
517 intc_irqpin_mask_unmask_prio(p, k, 1);
518
519 /* clear all pending interrupts */
520 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 0x0);
521
522 /* scan for shared interrupt lines */
523 ref_irq = p->irq[0].requested_irq;
524 p->shared_irqs = 1;
525 for (k = 1; k < nirqs; k++) {
526 if (ref_irq != p->irq[k].requested_irq) {
527 p->shared_irqs = 0;
528 break;
529 }
530 }
531
532 /* use more severe masking method if requested */
533 if (control_parent) {
534 enable_fn = intc_irqpin_irq_enable_force;
535 disable_fn = intc_irqpin_irq_disable_force;
536 } else if (!p->shared_irqs) {
537 enable_fn = intc_irqpin_irq_enable;
538 disable_fn = intc_irqpin_irq_disable;
539 } else {
540 enable_fn = intc_irqpin_shared_irq_enable;
541 disable_fn = intc_irqpin_shared_irq_disable;
542 }
543
544 irq_chip = &p->irq_chip;
545 irq_chip->name = name;
546 irq_chip->irq_mask = disable_fn;
547 irq_chip->irq_unmask = enable_fn;
548 irq_chip->irq_set_type = intc_irqpin_irq_set_type;
549 irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
550 irq_chip->flags = IRQCHIP_MASK_ON_SUSPEND;
551
552 p->irq_domain = irq_domain_add_simple(dev->of_node, nirqs, 0,
553 &intc_irqpin_irq_domain_ops, p);
554 if (!p->irq_domain) {
555 ret = -ENXIO;
556 dev_err(dev, "cannot initialize irq domain\n");
557 goto err0;
558 }
559
560 if (p->shared_irqs) {
561 /* request one shared interrupt */
562 if (devm_request_irq(dev, p->irq[0].requested_irq,
563 intc_irqpin_shared_irq_handler,
564 IRQF_SHARED, name, p)) {
565 dev_err(dev, "failed to request low IRQ\n");
566 ret = -ENOENT;
567 goto err1;
568 }
569 } else {
570 /* request interrupts one by one */
571 for (k = 0; k < nirqs; k++) {
572 if (devm_request_irq(dev, p->irq[k].requested_irq,
573 intc_irqpin_irq_handler, 0, name,
574 &p->irq[k])) {
575 dev_err(dev, "failed to request low IRQ\n");
576 ret = -ENOENT;
577 goto err1;
578 }
579 }
580 }
581
582 /* unmask all interrupts on prio level */
583 for (k = 0; k < nirqs; k++)
584 intc_irqpin_mask_unmask_prio(p, k, 0);
585
586 dev_info(dev, "driving %d irqs\n", nirqs);
587
588 return 0;
589
590err1:
591 irq_domain_remove(p->irq_domain);
592err0:
593 pm_runtime_put(dev);
594 pm_runtime_disable(dev);
595 return ret;
596}
597
598static int intc_irqpin_remove(struct platform_device *pdev)
599{
600 struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
601
602 irq_domain_remove(p->irq_domain);
603 pm_runtime_put(&pdev->dev);
604 pm_runtime_disable(&pdev->dev);
605 return 0;
606}
607
608static struct platform_driver intc_irqpin_device_driver = {
609 .probe = intc_irqpin_probe,
610 .remove = intc_irqpin_remove,
611 .driver = {
612 .name = "renesas_intc_irqpin",
613 .of_match_table = intc_irqpin_dt_ids,
614 }
615};
616
617static int __init intc_irqpin_init(void)
618{
619 return platform_driver_register(&intc_irqpin_device_driver);
620}
621postcore_initcall(intc_irqpin_init);
622
623static void __exit intc_irqpin_exit(void)
624{
625 platform_driver_unregister(&intc_irqpin_device_driver);
626}
627module_exit(intc_irqpin_exit);
628
629MODULE_AUTHOR("Magnus Damm");
630MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
631MODULE_LICENSE("GPL v2");