Merge tag '5.15-rc-ksmbd-part2' of git://git.samba.org/ksmbd
[linux-2.6-microblaze.git] / drivers / irqchip / irq-renesas-intc-irqpin.c
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/of_device.h>
21 #include <linux/pm_runtime.h>
22
23 #define INTC_IRQPIN_MAX 8 /* maximum 8 interrupts per driver instance */
24
25 #define INTC_IRQPIN_REG_SENSE 0 /* ICRn */
26 #define INTC_IRQPIN_REG_PRIO 1 /* INTPRInn */
27 #define INTC_IRQPIN_REG_SOURCE 2 /* INTREQnn */
28 #define INTC_IRQPIN_REG_MASK 3 /* INTMSKnn */
29 #define INTC_IRQPIN_REG_CLEAR 4 /* INTMSKCLRnn */
30 #define INTC_IRQPIN_REG_NR_MANDATORY 5
31 #define INTC_IRQPIN_REG_IRLM 5 /* ICR0 with IRLM bit (optional) */
32 #define INTC_IRQPIN_REG_NR 6
33
34 /* INTC external IRQ PIN hardware register access:
35  *
36  * SENSE is read-write 32-bit with 2-bits or 4-bits per IRQ (*)
37  * PRIO is read-write 32-bit with 4-bits per IRQ (**)
38  * SOURCE is read-only 32-bit or 8-bit with 1-bit per IRQ (***)
39  * MASK is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
40  * CLEAR is write-only 32-bit or 8-bit with 1-bit per IRQ (***)
41  *
42  * (*) May be accessed by more than one driver instance - lock needed
43  * (**) Read-modify-write access by one driver instance - lock needed
44  * (***) Accessed by one driver instance only - no locking needed
45  */
46
47 struct intc_irqpin_iomem {
48         void __iomem *iomem;
49         unsigned long (*read)(void __iomem *iomem);
50         void (*write)(void __iomem *iomem, unsigned long data);
51         int width;
52 };
53
54 struct intc_irqpin_irq {
55         int hw_irq;
56         int requested_irq;
57         int domain_irq;
58         struct intc_irqpin_priv *p;
59 };
60
61 struct intc_irqpin_priv {
62         struct intc_irqpin_iomem iomem[INTC_IRQPIN_REG_NR];
63         struct intc_irqpin_irq irq[INTC_IRQPIN_MAX];
64         unsigned int sense_bitfield_width;
65         struct platform_device *pdev;
66         struct irq_chip irq_chip;
67         struct irq_domain *irq_domain;
68         atomic_t wakeup_path;
69         unsigned shared_irqs:1;
70         u8 shared_irq_mask;
71 };
72
73 struct intc_irqpin_config {
74         int irlm_bit;           /* -1 if non-existent */
75 };
76
77 static unsigned long intc_irqpin_read32(void __iomem *iomem)
78 {
79         return ioread32(iomem);
80 }
81
82 static unsigned long intc_irqpin_read8(void __iomem *iomem)
83 {
84         return ioread8(iomem);
85 }
86
87 static void intc_irqpin_write32(void __iomem *iomem, unsigned long data)
88 {
89         iowrite32(data, iomem);
90 }
91
92 static void intc_irqpin_write8(void __iomem *iomem, unsigned long data)
93 {
94         iowrite8(data, iomem);
95 }
96
97 static inline unsigned long intc_irqpin_read(struct intc_irqpin_priv *p,
98                                              int reg)
99 {
100         struct intc_irqpin_iomem *i = &p->iomem[reg];
101
102         return i->read(i->iomem);
103 }
104
105 static inline void intc_irqpin_write(struct intc_irqpin_priv *p,
106                                      int reg, unsigned long data)
107 {
108         struct intc_irqpin_iomem *i = &p->iomem[reg];
109
110         i->write(i->iomem, data);
111 }
112
113 static inline unsigned long intc_irqpin_hwirq_mask(struct intc_irqpin_priv *p,
114                                                    int reg, int hw_irq)
115 {
116         return BIT((p->iomem[reg].width - 1) - hw_irq);
117 }
118
119 static inline void intc_irqpin_irq_write_hwirq(struct intc_irqpin_priv *p,
120                                                int reg, int hw_irq)
121 {
122         intc_irqpin_write(p, reg, intc_irqpin_hwirq_mask(p, reg, hw_irq));
123 }
124
125 static DEFINE_RAW_SPINLOCK(intc_irqpin_lock); /* only used by slow path */
126
127 static void intc_irqpin_read_modify_write(struct intc_irqpin_priv *p,
128                                           int reg, int shift,
129                                           int width, int value)
130 {
131         unsigned long flags;
132         unsigned long tmp;
133
134         raw_spin_lock_irqsave(&intc_irqpin_lock, flags);
135
136         tmp = intc_irqpin_read(p, reg);
137         tmp &= ~(((1 << width) - 1) << shift);
138         tmp |= value << shift;
139         intc_irqpin_write(p, reg, tmp);
140
141         raw_spin_unlock_irqrestore(&intc_irqpin_lock, flags);
142 }
143
144 static void intc_irqpin_mask_unmask_prio(struct intc_irqpin_priv *p,
145                                          int irq, int do_mask)
146 {
147         /* The PRIO register is assumed to be 32-bit with fixed 4-bit fields. */
148         int bitfield_width = 4;
149         int shift = 32 - (irq + 1) * bitfield_width;
150
151         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_PRIO,
152                                       shift, bitfield_width,
153                                       do_mask ? 0 : (1 << bitfield_width) - 1);
154 }
155
156 static int intc_irqpin_set_sense(struct intc_irqpin_priv *p, int irq, int value)
157 {
158         /* The SENSE register is assumed to be 32-bit. */
159         int bitfield_width = p->sense_bitfield_width;
160         int shift = 32 - (irq + 1) * bitfield_width;
161
162         dev_dbg(&p->pdev->dev, "sense irq = %d, mode = %d\n", irq, value);
163
164         if (value >= (1 << bitfield_width))
165                 return -EINVAL;
166
167         intc_irqpin_read_modify_write(p, INTC_IRQPIN_REG_SENSE, shift,
168                                       bitfield_width, value);
169         return 0;
170 }
171
172 static void intc_irqpin_dbg(struct intc_irqpin_irq *i, char *str)
173 {
174         dev_dbg(&i->p->pdev->dev, "%s (%d:%d:%d)\n",
175                 str, i->requested_irq, i->hw_irq, i->domain_irq);
176 }
177
178 static void intc_irqpin_irq_enable(struct irq_data *d)
179 {
180         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
181         int hw_irq = irqd_to_hwirq(d);
182
183         intc_irqpin_dbg(&p->irq[hw_irq], "enable");
184         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
185 }
186
187 static void intc_irqpin_irq_disable(struct irq_data *d)
188 {
189         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
190         int hw_irq = irqd_to_hwirq(d);
191
192         intc_irqpin_dbg(&p->irq[hw_irq], "disable");
193         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
194 }
195
196 static void intc_irqpin_shared_irq_enable(struct irq_data *d)
197 {
198         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
199         int hw_irq = irqd_to_hwirq(d);
200
201         intc_irqpin_dbg(&p->irq[hw_irq], "shared enable");
202         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_CLEAR, hw_irq);
203
204         p->shared_irq_mask &= ~BIT(hw_irq);
205 }
206
207 static void intc_irqpin_shared_irq_disable(struct irq_data *d)
208 {
209         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
210         int hw_irq = irqd_to_hwirq(d);
211
212         intc_irqpin_dbg(&p->irq[hw_irq], "shared disable");
213         intc_irqpin_irq_write_hwirq(p, INTC_IRQPIN_REG_MASK, hw_irq);
214
215         p->shared_irq_mask |= BIT(hw_irq);
216 }
217
218 static void intc_irqpin_irq_enable_force(struct irq_data *d)
219 {
220         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
221         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
222
223         intc_irqpin_irq_enable(d);
224
225         /* enable interrupt through parent interrupt controller,
226          * assumes non-shared interrupt with 1:1 mapping
227          * needed for busted IRQs on some SoCs like sh73a0
228          */
229         irq_get_chip(irq)->irq_unmask(irq_get_irq_data(irq));
230 }
231
232 static void intc_irqpin_irq_disable_force(struct irq_data *d)
233 {
234         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
235         int irq = p->irq[irqd_to_hwirq(d)].requested_irq;
236
237         /* disable interrupt through parent interrupt controller,
238          * assumes non-shared interrupt with 1:1 mapping
239          * needed for busted IRQs on some SoCs like sh73a0
240          */
241         irq_get_chip(irq)->irq_mask(irq_get_irq_data(irq));
242         intc_irqpin_irq_disable(d);
243 }
244
245 #define INTC_IRQ_SENSE_VALID 0x10
246 #define INTC_IRQ_SENSE(x) (x + INTC_IRQ_SENSE_VALID)
247
248 static unsigned char intc_irqpin_sense[IRQ_TYPE_SENSE_MASK + 1] = {
249         [IRQ_TYPE_EDGE_FALLING] = INTC_IRQ_SENSE(0x00),
250         [IRQ_TYPE_EDGE_RISING] = INTC_IRQ_SENSE(0x01),
251         [IRQ_TYPE_LEVEL_LOW] = INTC_IRQ_SENSE(0x02),
252         [IRQ_TYPE_LEVEL_HIGH] = INTC_IRQ_SENSE(0x03),
253         [IRQ_TYPE_EDGE_BOTH] = INTC_IRQ_SENSE(0x04),
254 };
255
256 static int intc_irqpin_irq_set_type(struct irq_data *d, unsigned int type)
257 {
258         unsigned char value = intc_irqpin_sense[type & IRQ_TYPE_SENSE_MASK];
259         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
260
261         if (!(value & INTC_IRQ_SENSE_VALID))
262                 return -EINVAL;
263
264         return intc_irqpin_set_sense(p, irqd_to_hwirq(d),
265                                      value ^ INTC_IRQ_SENSE_VALID);
266 }
267
268 static int intc_irqpin_irq_set_wake(struct irq_data *d, unsigned int on)
269 {
270         struct intc_irqpin_priv *p = irq_data_get_irq_chip_data(d);
271         int hw_irq = irqd_to_hwirq(d);
272
273         irq_set_irq_wake(p->irq[hw_irq].requested_irq, on);
274         if (on)
275                 atomic_inc(&p->wakeup_path);
276         else
277                 atomic_dec(&p->wakeup_path);
278
279         return 0;
280 }
281
282 static irqreturn_t intc_irqpin_irq_handler(int irq, void *dev_id)
283 {
284         struct intc_irqpin_irq *i = dev_id;
285         struct intc_irqpin_priv *p = i->p;
286         unsigned long bit;
287
288         intc_irqpin_dbg(i, "demux1");
289         bit = intc_irqpin_hwirq_mask(p, INTC_IRQPIN_REG_SOURCE, i->hw_irq);
290
291         if (intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE) & bit) {
292                 intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, ~bit);
293                 intc_irqpin_dbg(i, "demux2");
294                 generic_handle_irq(i->domain_irq);
295                 return IRQ_HANDLED;
296         }
297         return IRQ_NONE;
298 }
299
300 static irqreturn_t intc_irqpin_shared_irq_handler(int irq, void *dev_id)
301 {
302         struct intc_irqpin_priv *p = dev_id;
303         unsigned int reg_source = intc_irqpin_read(p, INTC_IRQPIN_REG_SOURCE);
304         irqreturn_t status = IRQ_NONE;
305         int k;
306
307         for (k = 0; k < 8; k++) {
308                 if (reg_source & BIT(7 - k)) {
309                         if (BIT(k) & p->shared_irq_mask)
310                                 continue;
311
312                         status |= intc_irqpin_irq_handler(irq, &p->irq[k]);
313                 }
314         }
315
316         return status;
317 }
318
319 /*
320  * This lock class tells lockdep that INTC External IRQ Pin irqs are in a
321  * different category than their parents, so it won't report false recursion.
322  */
323 static struct lock_class_key intc_irqpin_irq_lock_class;
324
325 /* And this is for the request mutex */
326 static struct lock_class_key intc_irqpin_irq_request_class;
327
328 static int intc_irqpin_irq_domain_map(struct irq_domain *h, unsigned int virq,
329                                       irq_hw_number_t hw)
330 {
331         struct intc_irqpin_priv *p = h->host_data;
332
333         p->irq[hw].domain_irq = virq;
334         p->irq[hw].hw_irq = hw;
335
336         intc_irqpin_dbg(&p->irq[hw], "map");
337         irq_set_chip_data(virq, h->host_data);
338         irq_set_lockdep_class(virq, &intc_irqpin_irq_lock_class,
339                               &intc_irqpin_irq_request_class);
340         irq_set_chip_and_handler(virq, &p->irq_chip, handle_level_irq);
341         return 0;
342 }
343
344 static const struct irq_domain_ops intc_irqpin_irq_domain_ops = {
345         .map    = intc_irqpin_irq_domain_map,
346         .xlate  = irq_domain_xlate_twocell,
347 };
348
349 static const struct intc_irqpin_config intc_irqpin_irlm_r8a777x = {
350         .irlm_bit = 23, /* ICR0.IRLM0 */
351 };
352
353 static const struct intc_irqpin_config intc_irqpin_rmobile = {
354         .irlm_bit = -1,
355 };
356
357 static const struct of_device_id intc_irqpin_dt_ids[] = {
358         { .compatible = "renesas,intc-irqpin", },
359         { .compatible = "renesas,intc-irqpin-r8a7778",
360           .data = &intc_irqpin_irlm_r8a777x },
361         { .compatible = "renesas,intc-irqpin-r8a7779",
362           .data = &intc_irqpin_irlm_r8a777x },
363         { .compatible = "renesas,intc-irqpin-r8a7740",
364           .data = &intc_irqpin_rmobile },
365         { .compatible = "renesas,intc-irqpin-sh73a0",
366           .data = &intc_irqpin_rmobile },
367         {},
368 };
369 MODULE_DEVICE_TABLE(of, intc_irqpin_dt_ids);
370
371 static int intc_irqpin_probe(struct platform_device *pdev)
372 {
373         const struct intc_irqpin_config *config;
374         struct device *dev = &pdev->dev;
375         struct intc_irqpin_priv *p;
376         struct intc_irqpin_iomem *i;
377         struct resource *io[INTC_IRQPIN_REG_NR];
378         struct resource *irq;
379         struct irq_chip *irq_chip;
380         void (*enable_fn)(struct irq_data *d);
381         void (*disable_fn)(struct irq_data *d);
382         const char *name = dev_name(dev);
383         bool control_parent;
384         unsigned int nirqs;
385         int ref_irq;
386         int ret;
387         int k;
388
389         p = devm_kzalloc(dev, sizeof(*p), GFP_KERNEL);
390         if (!p)
391                 return -ENOMEM;
392
393         /* deal with driver instance configuration */
394         of_property_read_u32(dev->of_node, "sense-bitfield-width",
395                              &p->sense_bitfield_width);
396         control_parent = of_property_read_bool(dev->of_node, "control-parent");
397         if (!p->sense_bitfield_width)
398                 p->sense_bitfield_width = 4; /* default to 4 bits */
399
400         p->pdev = pdev;
401         platform_set_drvdata(pdev, p);
402
403         config = of_device_get_match_data(dev);
404
405         pm_runtime_enable(dev);
406         pm_runtime_get_sync(dev);
407
408         /* get hold of register banks */
409         memset(io, 0, sizeof(io));
410         for (k = 0; k < INTC_IRQPIN_REG_NR; k++) {
411                 io[k] = platform_get_resource(pdev, IORESOURCE_MEM, k);
412                 if (!io[k] && k < INTC_IRQPIN_REG_NR_MANDATORY) {
413                         dev_err(dev, "not enough IOMEM resources\n");
414                         ret = -EINVAL;
415                         goto err0;
416                 }
417         }
418
419         /* allow any number of IRQs between 1 and INTC_IRQPIN_MAX */
420         for (k = 0; k < INTC_IRQPIN_MAX; k++) {
421                 irq = platform_get_resource(pdev, IORESOURCE_IRQ, k);
422                 if (!irq)
423                         break;
424
425                 p->irq[k].p = p;
426                 p->irq[k].requested_irq = irq->start;
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(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, io[k]->start,
462                                         resource_size(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                                                       config->irlm_bit, 1, 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, k, 1);
482
483         /* clear all pending interrupts */
484         intc_irqpin_write(p, INTC_IRQPIN_REG_SOURCE, 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->parent_device = dev;
511         irq_chip->irq_mask = disable_fn;
512         irq_chip->irq_unmask = enable_fn;
513         irq_chip->irq_set_type = intc_irqpin_irq_set_type;
514         irq_chip->irq_set_wake = intc_irqpin_irq_set_wake;
515         irq_chip->flags = IRQCHIP_MASK_ON_SUSPEND;
516
517         p->irq_domain = irq_domain_add_simple(dev->of_node, nirqs, 0,
518                                               &intc_irqpin_irq_domain_ops, p);
519         if (!p->irq_domain) {
520                 ret = -ENXIO;
521                 dev_err(dev, "cannot initialize irq domain\n");
522                 goto err0;
523         }
524
525         if (p->shared_irqs) {
526                 /* request one shared interrupt */
527                 if (devm_request_irq(dev, p->irq[0].requested_irq,
528                                 intc_irqpin_shared_irq_handler,
529                                 IRQF_SHARED, name, p)) {
530                         dev_err(dev, "failed to request low IRQ\n");
531                         ret = -ENOENT;
532                         goto err1;
533                 }
534         } else {
535                 /* request interrupts one by one */
536                 for (k = 0; k < nirqs; k++) {
537                         if (devm_request_irq(dev, p->irq[k].requested_irq,
538                                              intc_irqpin_irq_handler, 0, name,
539                                              &p->irq[k])) {
540                                 dev_err(dev, "failed to request low IRQ\n");
541                                 ret = -ENOENT;
542                                 goto err1;
543                         }
544                 }
545         }
546
547         /* unmask all interrupts on prio level */
548         for (k = 0; k < nirqs; k++)
549                 intc_irqpin_mask_unmask_prio(p, k, 0);
550
551         dev_info(dev, "driving %d irqs\n", nirqs);
552
553         return 0;
554
555 err1:
556         irq_domain_remove(p->irq_domain);
557 err0:
558         pm_runtime_put(dev);
559         pm_runtime_disable(dev);
560         return ret;
561 }
562
563 static int intc_irqpin_remove(struct platform_device *pdev)
564 {
565         struct intc_irqpin_priv *p = platform_get_drvdata(pdev);
566
567         irq_domain_remove(p->irq_domain);
568         pm_runtime_put(&pdev->dev);
569         pm_runtime_disable(&pdev->dev);
570         return 0;
571 }
572
573 static int __maybe_unused intc_irqpin_suspend(struct device *dev)
574 {
575         struct intc_irqpin_priv *p = dev_get_drvdata(dev);
576
577         if (atomic_read(&p->wakeup_path))
578                 device_set_wakeup_path(dev);
579
580         return 0;
581 }
582
583 static SIMPLE_DEV_PM_OPS(intc_irqpin_pm_ops, intc_irqpin_suspend, NULL);
584
585 static struct platform_driver intc_irqpin_device_driver = {
586         .probe          = intc_irqpin_probe,
587         .remove         = intc_irqpin_remove,
588         .driver         = {
589                 .name   = "renesas_intc_irqpin",
590                 .of_match_table = intc_irqpin_dt_ids,
591                 .pm     = &intc_irqpin_pm_ops,
592         }
593 };
594
595 static int __init intc_irqpin_init(void)
596 {
597         return platform_driver_register(&intc_irqpin_device_driver);
598 }
599 postcore_initcall(intc_irqpin_init);
600
601 static void __exit intc_irqpin_exit(void)
602 {
603         platform_driver_unregister(&intc_irqpin_device_driver);
604 }
605 module_exit(intc_irqpin_exit);
606
607 MODULE_AUTHOR("Magnus Damm");
608 MODULE_DESCRIPTION("Renesas INTC External IRQ Pin Driver");
609 MODULE_LICENSE("GPL v2");