1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Renesas INTC External IRQ Pin Driver
4 *
5 * Copyright (C) 2013 Magnus Damm
6 */
7
8#include <linux/init.h>
9#include <linux/of.h>
10#include <linux/platform_device.h>
11#include <linux/spinlock.h>
12#include <linux/interrupt.h>
13#include <linux/ioport.h>
14#include <linux/io.h>
15#include <linux/irq.h>
16#include <linux/irqdomain.h>
17#include <linux/err.h>
18#include <linux/slab.h>
19#include <linux/module.h>
20#include <linux/pm_runtime.h>
21
22#define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
23
24#define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
25#define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
26#define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
27#define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
28#define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
29#define INTC_IRQPIN_REG_NR_MANDATORY 5
30#define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
31#define INTC_IRQPIN_REG_NR 6
32
33/* INTC external IRQ PIN hardware register access:
34 *
35 * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
36 * PRIO is read-write 32-bit with 4-bits per IRQ (**)
37 * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
38 * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
39 * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
40 *
41 * (*) May be accessed by more than one driver instance - lock needed
42 * (**) Read-modify-write access by one driver instance - lock needed
43 * (***) Accessed by one driver instance only - no locking needed
44 */
45
46struct intc_irqpin_iomem {
47 void __iomem *iomem;
48 unsigned long (*read)(void __iomem *iomem);
49 void (*write)(void __iomem *iomem, unsigned long data);
50 int width;
51};
52
53struct intc_irqpin_irq {
54 int hw_irq;
55 int requested_irq;
56 int domain_irq;
57 struct intc_irqpin_priv *p;
58};
59
60struct intc_irqpin_priv {
61 struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
62 struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
63 unsigned int sense_bitfield_width;
64 struct platform_device *pdev;
65 struct irq_chip irq_chip;
66 struct irq_domain *irq_domain;
67 atomic_t wakeup_path;
68 unsigned shared_irqs:1;
69 u8 shared_irq_mask;
70};
71
72struct intc_irqpin_config {
73 int irlm_bit; /* -1 if non-existent */
74};
75
76static unsigned long intc_irqpin_read32(void __iomem *iomem)
77{
78 return ioread32(iomem);
79}
80
81static unsigned long intc_irqpin_read8(void __iomem *iomem)
82{
83 return ioread8(iomem);
84}
85
86static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
87{
88 iowrite32(data, iomem);
89}
90
91static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
92{
93 iowrite8(data, iomem);
94}
95
96static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
97 int reg)
98{
99 struct intc_irqpin_iomem *i = &p->iomem[reg];
100
101 return i->read(i->iomem);
102}
103
104static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
105 int reg, unsigned long data)
106{
107 struct intc_irqpin_iomem *i = &p->iomem[reg];
108
109 i->write(i->iomem, data);
110}
111
112static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
113 int reg, int hw_irq)
114{
115 return BIT((p->iomem[reg].width - 1) - hw_irq);
116}
117
118static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
119 int reg, int hw_irq)
120{
121 intc_irqpin_write(p, reg, data: intc_irqpin_hwirq_mask(p, reg, hw_irq));
122}
123
124static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
125
126static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
127 int reg, int shift,
128 int width, int value)
129{
130 unsigned long flags;
131 unsigned long tmp;
132
133 raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
134
135 tmp = intc_irqpin_read(p, reg);
136 tmp &= ~(((1 << width) - 1) << shift);
137 tmp |= value << shift;
138 intc_irqpin_write(p, reg, data: tmp);
139
140 raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
141}
142
143static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
144 int irq, int do_mask)
145{
146 /* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
147 int bitfield_width = 4;
148 int shift = 32 - (irq + 1) * bitfield_width;
149
150 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
151 shift, width: bitfield_width,
152 value: do_mask ? 0 : (1 << bitfield_width) - 1);
153}
154
155static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
156{
157 /* The SENSE register is assumed to be 32-bit. */
158 int bitfield_width = p->sense_bitfield_width;
159 int shift = 32 - (irq + 1) * bitfield_width;
160
161 dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
162
163 if (value >= (1 << bitfield_width))
164 return -EINVAL;
165
166 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
167 width: bitfield_width, value);
168 return 0;
169}
170
171static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
172{
173 dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
174 str, i->requested_irq, i->hw_irq, i->domain_irq);
175}
176
177static void intc_irqpin_irq_enable(struct irq_data *d)
178{
179 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
180 int hw_irq = irqd_to_hwirq(d);
181
182 intc_irqpin_dbg(i: &p->irq[hw_irq], str: "enable");
183 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
184}
185
186static void intc_irqpin_irq_disable(struct irq_data *d)
187{
188 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
189 int hw_irq = irqd_to_hwirq(d);
190
191 intc_irqpin_dbg(i: &p->irq[hw_irq], str: "disable");
192 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
193}
194
195static void intc_irqpin_shared_irq_enable(struct irq_data *d)
196{
197 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
198 int hw_irq = irqd_to_hwirq(d);
199
200 intc_irqpin_dbg(i: &p->irq[hw_irq], str: "shared enable");
201 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
202
203 p->shared_irq_mask &= ~BIT(hw_irq);
204}
205
206static void intc_irqpin_shared_irq_disable(struct irq_data *d)
207{
208 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
209 int hw_irq = irqd_to_hwirq(d);
210
211 intc_irqpin_dbg(i: &p->irq[hw_irq], str: "shared disable");
212 intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
213
214 p->shared_irq_mask |= BIT(hw_irq);
215}
216
217static void intc_irqpin_irq_enable_force(struct irq_data *d)
218{
219 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
220 int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
221
222 intc_irqpin_irq_enable(d);
223
224 /* enable interrupt through parent interrupt controller,
225 * assumes non-shared interrupt with 1:1 mapping
226 * needed for busted IRQs on some SoCs like sh73a0
227 */
228 irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
229}
230
231static void intc_irqpin_irq_disable_force(struct irq_data *d)
232{
233 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
234 int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
235
236 /* disable interrupt through parent interrupt controller,
237 * assumes non-shared interrupt with 1:1 mapping
238 * needed for busted IRQs on some SoCs like sh73a0
239 */
240 irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
241 intc_irqpin_irq_disable(d);
242}
243
244#define INTC_IRQ_SENSE_VALID 0x10
245#define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
246
247static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
248 [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
249 [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
250 [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
251 [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
252 [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
253};
254
255static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
256{
257 unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
258 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
259
260 if (!(value & INTC_IRQ_SENSE_VALID))
261 return -EINVAL;
262
263 return intc_irqpin_set_sense(p, irq: irqd_to_hwirq(d),
264 value: value ^ INTC_IRQ_SENSE_VALID);
265}
266
267static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
268{
269 struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
270 int hw_irq = irqd_to_hwirq(d);
271
272 irq_set_irq_wake(irq: p->irq[hw_irq].requested_irq, on);
273 if (on)
274 atomic_inc(v: &p->wakeup_path);
275 else
276 atomic_dec(v: &p->wakeup_path);
277
278 return 0;
279}
280
281static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
282{
283 struct intc_irqpin_irq *i = dev_id;
284 struct intc_irqpin_priv *p = i->p;
285 unsigned long bit;
286
287 intc_irqpin_dbg(i, str: "demux1");
288 bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, hw_irq: i->hw_irq);
289
290 if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
291 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, data: ~bit);
292 intc_irqpin_dbg(i, str: "demux2");
293 generic_handle_irq(irq: i->domain_irq);
294 return IRQ_HANDLED;
295 }
296 return IRQ_NONE;
297}
298
299static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
300{
301 struct intc_irqpin_priv *p = dev_id;
302 unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
303 irqreturn_t status = IRQ_NONE;
304 int k;
305
306 for (k = 0; k < 8; k++) {
307 if (reg_source & BIT(7 - k)) {
308 if (BIT(k) & p->shared_irq_mask)
309 continue;
310
311 status |= intc_irqpin_irq_handler(irq, dev_id: &p->irq[k]);
312 }
313 }
314
315 return status;
316}
317
318/*
319 * This lock class tells lockdep that INTC External IRQ Pin irqs are in a
320 * different category than their parents, so it won't report false recursion.
321 */
322static struct lock_class_key intc_irqpin_irq_lock_class;
323
324/* And this is for the request mutex */
325static struct lock_class_key intc_irqpin_irq_request_class;
326
327static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
328 irq_hw_number_t hw)
329{
330 struct intc_irqpin_priv *p = h->host_data;
331
332 p->irq[hw].domain_irq = virq;
333 p->irq[hw].hw_irq = hw;
334
335 intc_irqpin_dbg(i: &p->irq[hw], str: "map");
336 irq_set_chip_data(irq: virq, data: h->host_data);
337 irq_set_lockdep_class(irq: virq, lock_class: &intc_irqpin_irq_lock_class,
338 request_class: &intc_irqpin_irq_request_class);
339 irq_set_chip_and_handler(irq: virq, chip: &p->irq_chip, handle: handle_level_irq);
340 return 0;
341}
342
343static const struct irq_domain_ops intc_irqpin_irq_domain_ops = {
344 .map = intc_irqpin_irq_domain_map,
345 .xlate = irq_domain_xlate_twocell,
346};
347
348static const struct intc_irqpin_config intc_irqpin_irlm_r8a777x = {
349 .irlm_bit = 23, /* ICR0.IRLM0 */
350};
351
352static const struct intc_irqpin_config intc_irqpin_rmobile = {
353 .irlm_bit = -1,
354};
355
356static const struct of_device_id intc_irqpin_dt_ids[] = {
357 { .compatible = "renesas,intc-irqpin", },
358 { .compatible = "renesas,intc-irqpin-r8a7778",
359 .data = &intc_irqpin_irlm_r8a777x },
360 { .compatible = "renesas,intc-irqpin-r8a7779",
361 .data = &intc_irqpin_irlm_r8a777x },
362 { .compatible = "renesas,intc-irqpin-r8a7740",
363 .data = &intc_irqpin_rmobile },
364 { .compatible = "renesas,intc-irqpin-sh73a0",
365 .data = &intc_irqpin_rmobile },
366 {},
367};
368MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
369
370static int intc_irqpin_probe(struct platform_device *pdev)
371{
372 const struct intc_irqpin_config *config;
373 struct device *dev = &pdev->dev;
374 struct intc_irqpin_priv *p;
375 struct intc_irqpin_iomem *i;
376 struct resource *io[INTC_IRQPIN_REG_NR];
377 struct irq_chip *irq_chip;
378 void (*enable_fn)(struct irq_data *d);
379 void (*disable_fn)(struct irq_data *d);
380 const char *name = dev_name(dev);
381 bool control_parent;
382 unsigned int nirqs;
383 int ref_irq;
384 int ret;
385 int k;
386
387 p = devm_kzalloc(dev, size: sizeof(*p), GFP_KERNEL);
388 if (!p)
389 return -ENOMEM;
390
391 /* deal with driver instance configuration */
392 of_property_read_u32(np: dev->of_node, propname: "sense-bitfield-width",
393 out_value: &p->sense_bitfield_width);
394 control_parent = of_property_read_bool(np: dev->of_node, propname: "control-parent");
395 if (!p->sense_bitfield_width)
396 p->sense_bitfield_width = 4; /* default to 4 bits */
397
398 p->pdev = pdev;
399 platform_set_drvdata(pdev, data: p);
400
401 config = of_device_get_match_data(dev);
402
403 pm_runtime_enable(dev);
404 pm_runtime_get_sync(dev);
405
406 /* get hold of register banks */
407 memset(io, 0, sizeof(io));
408 for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
409 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
410 if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
411 dev_err(dev, "not enough IOMEM resources\n");
412 ret = -EINVAL;
413 goto err0;
414 }
415 }
416
417 /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
418 for (k = 0; k < INTC_IRQPIN_MAX; k++) {
419 ret = platform_get_irq_optional(pdev, k);
420 if (ret == -ENXIO)
421 break;
422 if (ret < 0)
423 goto err0;
424
425 p->irq[k].p = p;
426 p->irq[k].requested_irq = ret;
427 }
428
429 nirqs = k;
430 if (nirqs < 1) {
431 dev_err(dev, "not enough IRQ resources\n");
432 ret = -EINVAL;
433 goto err0;
434 }
435
436 /* ioremap IOMEM and setup read/write callbacks */
437 for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
438 i = &p->iomem[k];
439
440 /* handle optional registers */
441 if (!io[k])
442 continue;
443
444 switch (resource_size(res: io[k])) {
445 case 1:
446 i->width = 8;
447 i->read = intc_irqpin_read8;
448 i->write = intc_irqpin_write8;
449 break;
450 case 4:
451 i->width = 32;
452 i->read = intc_irqpin_read32;
453 i->write = intc_irqpin_write32;
454 break;
455 default:
456 dev_err(dev, "IOMEM size mismatch\n");
457 ret = -EINVAL;
458 goto err0;
459 }
460
461 i->iomem = devm_ioremap(dev, offset: io[k]->start,
462 size: resource_size(res: io[k]));
463 if (!i->iomem) {
464 dev_err(dev, "failed to remap IOMEM\n");
465 ret = -ENXIO;
466 goto err0;
467 }
468 }
469
470 /* configure "individual IRQ mode" where needed */
471 if (config && config->irlm_bit >= 0) {
472 if (io[INTC_IRQPIN_REG_IRLM])
473 intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_IRLM,
474 shift: config->irlm_bit, width: 1, value: 1);
475 else
476 dev_warn(dev, "unable to select IRLM mode\n");
477 }
478
479 /* mask all interrupts using priority */
480 for (k = 0; k < nirqs; k++)
481 intc_irqpin_mask_unmask_prio(p, irq: k, do_mask: 1);
482
483 /* clear all pending interrupts */
484 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, data: 0x0);
485
486 /* scan for shared interrupt lines */
487 ref_irq = p->irq[0].requested_irq;
488 p->shared_irqs = 1;
489 for (k = 1; k < nirqs; k++) {
490 if (ref_irq != p->irq[k].requested_irq) {
491 p->shared_irqs = 0;
492 break;
493 }
494 }
495
496 /* use more severe masking method if requested */
497 if (control_parent) {
498 enable_fn = intc_irqpin_irq_enable_force;
499 disable_fn = intc_irqpin_irq_disable_force;
500 } else if (!p->shared_irqs) {
501 enable_fn = intc_irqpin_irq_enable;
502 disable_fn = intc_irqpin_irq_disable;
503 } else {
504 enable_fn = intc_irqpin_shared_irq_enable;
505 disable_fn = intc_irqpin_shared_irq_disable;
506 }
507
508 irq_chip = &p->irq_chip;
509 irq_chip->name = "intc-irqpin";
510 irq_chip->irq_mask = disable_fn;
511 irq_chip->irq_unmask = enable_fn;
512 irq_chip->irq_set_type = intc_irqpin_irq_set_type;
513 irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
514 irq_chip->flags = IRQCHIP_MASK_ON_SUSPEND;
515
516 p->irq_domain = irq_domain_add_simple(of_node: dev->of_node, size: nirqs, first_irq: 0,
517 ops: &intc_irqpin_irq_domain_ops, host_data: p);
518 if (!p->irq_domain) {
519 ret = -ENXIO;
520 dev_err(dev, "cannot initialize irq domain\n");
521 goto err0;
522 }
523
524 irq_domain_set_pm_device(d: p->irq_domain, dev);
525
526 if (p->shared_irqs) {
527 /* request one shared interrupt */
528 if (devm_request_irq(dev, irq: p->irq[0].requested_irq,
529 handler: intc_irqpin_shared_irq_handler,
530 IRQF_SHARED, devname: name, dev_id: p)) {
531 dev_err(dev, "failed to request low IRQ\n");
532 ret = -ENOENT;
533 goto err1;
534 }
535 } else {
536 /* request interrupts one by one */
537 for (k = 0; k < nirqs; k++) {
538 if (devm_request_irq(dev, irq: p->irq[k].requested_irq,
539 handler: intc_irqpin_irq_handler, irqflags: 0, devname: name,
540 dev_id: &p->irq[k])) {
541 dev_err(dev, "failed to request low IRQ\n");
542 ret = -ENOENT;
543 goto err1;
544 }
545 }
546 }
547
548 /* unmask all interrupts on prio level */
549 for (k = 0; k < nirqs; k++)
550 intc_irqpin_mask_unmask_prio(p, irq: k, do_mask: 0);
551
552 dev_info(dev, "driving %d irqs\n", nirqs);
553
554 return 0;
555
556err1:
557 irq_domain_remove(host: p->irq_domain);
558err0:
559 pm_runtime_put(dev);
560 pm_runtime_disable(dev);
561 return ret;
562}
563
564static int intc_irqpin_remove(struct platform_device *pdev)
565{
566 struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
567
568 irq_domain_remove(host: p->irq_domain);
569 pm_runtime_put(dev: &pdev->dev);
570 pm_runtime_disable(dev: &pdev->dev);
571 return 0;
572}
573
574static int __maybe_unused intc_irqpin_suspend(struct device *dev)
575{
576 struct intc_irqpin_priv *p = dev_get_drvdata(dev);
577
578 if (atomic_read(v: &p->wakeup_path))
579 device_set_wakeup_path(dev);
580
581 return 0;
582}
583
584static SIMPLE_DEV_PM_OPS(intc_irqpin_pm_ops, intc_irqpin_suspend, NULL);
585
586static struct platform_driver intc_irqpin_device_driver = {
587 .probe = intc_irqpin_probe,
588 .remove = intc_irqpin_remove,
589 .driver = {
590 .name = "renesas_intc_irqpin",
591 .of_match_table = intc_irqpin_dt_ids,
592 .pm = &intc_irqpin_pm_ops,
593 }
594};
595
596static int __init intc_irqpin_init(void)
597{
598 return platform_driver_register(&intc_irqpin_device_driver);
599}
600postcore_initcall(intc_irqpin_init);
601
602static void __exit intc_irqpin_exit(void)
603{
604 platform_driver_unregister(&intc_irqpin_device_driver);
605}
606module_exit(intc_irqpin_exit);
607
608MODULE_AUTHOR("Magnus Damm");
609MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
610

source code of linux/drivers/irqchip/irq-renesas-intc-irqpin.c