1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * linux/arch/arm/common/vic.c
4 *
5 * Copyright (C) 1999 - 2003 ARM Limited
6 * Copyright (C) 2000 Deep Blue Solutions Ltd
7 */
8
9 #include <linux/export.h>
10 #include <linux/init.h>
11 #include <linux/list.h>
12 #include <linux/io.h>
13 #include <linux/irq.h>
14 #include <linux/irqchip.h>
15 #include <linux/irqchip/chained_irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/of.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
20 #include <linux/syscore_ops.h>
21 #include <linux/device.h>
22 #include <linux/amba/bus.h>
23 #include <linux/irqchip/arm-vic.h>
24
25 #include <asm/exception.h>
26 #include <asm/irq.h>
27
28 #define VIC_IRQ_STATUS 0x00
29 #define VIC_FIQ_STATUS 0x04
30 #define VIC_RAW_STATUS 0x08
31 #define VIC_INT_SELECT 0x0c /* 1 = FIQ, 0 = IRQ */
32 #define VIC_INT_ENABLE 0x10 /* 1 = enable, 0 = disable */
33 #define VIC_INT_ENABLE_CLEAR 0x14
34 #define VIC_INT_SOFT 0x18
35 #define VIC_INT_SOFT_CLEAR 0x1c
36 #define VIC_PROTECT 0x20
37 #define VIC_PL190_VECT_ADDR 0x30 /* PL190 only */
38 #define VIC_PL190_DEF_VECT_ADDR 0x34 /* PL190 only */
39
40 #define VIC_VECT_ADDR0 0x100 /* 0 to 15 (0..31 PL192) */
41 #define VIC_VECT_CNTL0 0x200 /* 0 to 15 (0..31 PL192) */
42 #define VIC_ITCR 0x300 /* VIC test control register */
43
44 #define VIC_VECT_CNTL_ENABLE (1 << 5)
45
46 #define VIC_PL192_VECT_ADDR 0xF00
47
48 /**
49 * struct vic_device - VIC PM device
50 * @parent_irq: The parent IRQ number of the VIC if cascaded, or 0.
51 * @irq: The IRQ number for the base of the VIC.
52 * @base: The register base for the VIC.
53 * @valid_sources: A bitmask of valid interrupts
54 * @resume_sources: A bitmask of interrupts for resume.
55 * @resume_irqs: The IRQs enabled for resume.
56 * @int_select: Save for VIC_INT_SELECT.
57 * @int_enable: Save for VIC_INT_ENABLE.
58 * @soft_int: Save for VIC_INT_SOFT.
59 * @protect: Save for VIC_PROTECT.
60 * @domain: The IRQ domain for the VIC.
61 */
62 struct vic_device {
63 void __iomem *base;
64 int irq;
65 u32 valid_sources;
66 u32 resume_sources;
67 u32 resume_irqs;
68 u32 int_select;
69 u32 int_enable;
70 u32 soft_int;
71 u32 protect;
72 struct irq_domain *domain;
73 };
74
75 /* we cannot allocate memory when VICs are initially registered */
76 static struct vic_device vic_devices[CONFIG_ARM_VIC_NR];
77
78 static int vic_id;
79
80 static void vic_handle_irq(struct pt_regs *regs);
81
82 /**
83 * vic_init2 - common initialisation code
84 * @base: Base of the VIC.
85 *
86 * Common initialisation code for registration
87 * and resume.
88 */
vic_init2(void __iomem * base)89 static void vic_init2(void __iomem *base)
90 {
91 int i;
92
93 for (i = 0; i < 16; i++) {
94 void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
95 writel(VIC_VECT_CNTL_ENABLE | i, reg);
96 }
97
98 writel(32, base + VIC_PL190_DEF_VECT_ADDR);
99 }
100
101 #ifdef CONFIG_PM
resume_one_vic(struct vic_device * vic)102 static void resume_one_vic(struct vic_device *vic)
103 {
104 void __iomem *base = vic->base;
105
106 printk(KERN_DEBUG "%s: resuming vic at %p\n", __func__, base);
107
108 /* re-initialise static settings */
109 vic_init2(base);
110
111 writel(vic->int_select, base + VIC_INT_SELECT);
112 writel(vic->protect, base + VIC_PROTECT);
113
114 /* set the enabled ints and then clear the non-enabled */
115 writel(vic->int_enable, base + VIC_INT_ENABLE);
116 writel(~vic->int_enable, base + VIC_INT_ENABLE_CLEAR);
117
118 /* and the same for the soft-int register */
119
120 writel(vic->soft_int, base + VIC_INT_SOFT);
121 writel(~vic->soft_int, base + VIC_INT_SOFT_CLEAR);
122 }
123
vic_resume(void)124 static void vic_resume(void)
125 {
126 int id;
127
128 for (id = vic_id - 1; id >= 0; id--)
129 resume_one_vic(vic_devices + id);
130 }
131
suspend_one_vic(struct vic_device * vic)132 static void suspend_one_vic(struct vic_device *vic)
133 {
134 void __iomem *base = vic->base;
135
136 printk(KERN_DEBUG "%s: suspending vic at %p\n", __func__, base);
137
138 vic->int_select = readl(base + VIC_INT_SELECT);
139 vic->int_enable = readl(base + VIC_INT_ENABLE);
140 vic->soft_int = readl(base + VIC_INT_SOFT);
141 vic->protect = readl(base + VIC_PROTECT);
142
143 /* set the interrupts (if any) that are used for
144 * resuming the system */
145
146 writel(vic->resume_irqs, base + VIC_INT_ENABLE);
147 writel(~vic->resume_irqs, base + VIC_INT_ENABLE_CLEAR);
148 }
149
vic_suspend(void)150 static int vic_suspend(void)
151 {
152 int id;
153
154 for (id = 0; id < vic_id; id++)
155 suspend_one_vic(vic_devices + id);
156
157 return 0;
158 }
159
160 static struct syscore_ops vic_syscore_ops = {
161 .suspend = vic_suspend,
162 .resume = vic_resume,
163 };
164
165 /**
166 * vic_pm_init - initcall to register VIC pm
167 *
168 * This is called via late_initcall() to register
169 * the resources for the VICs due to the early
170 * nature of the VIC's registration.
171 */
vic_pm_init(void)172 static int __init vic_pm_init(void)
173 {
174 if (vic_id > 0)
175 register_syscore_ops(&vic_syscore_ops);
176
177 return 0;
178 }
179 late_initcall(vic_pm_init);
180 #endif /* CONFIG_PM */
181
182 static struct irq_chip vic_chip;
183
vic_irqdomain_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hwirq)184 static int vic_irqdomain_map(struct irq_domain *d, unsigned int irq,
185 irq_hw_number_t hwirq)
186 {
187 struct vic_device *v = d->host_data;
188
189 /* Skip invalid IRQs, only register handlers for the real ones */
190 if (!(v->valid_sources & (1 << hwirq)))
191 return -EPERM;
192 irq_set_chip_and_handler(irq, &vic_chip, handle_level_irq);
193 irq_set_chip_data(irq, v->base);
194 irq_set_probe(irq);
195 return 0;
196 }
197
198 /*
199 * Handle each interrupt in a single VIC. Returns non-zero if we've
200 * handled at least one interrupt. This reads the status register
201 * before handling each interrupt, which is necessary given that
202 * handle_IRQ may briefly re-enable interrupts for soft IRQ handling.
203 */
handle_one_vic(struct vic_device * vic,struct pt_regs * regs)204 static int handle_one_vic(struct vic_device *vic, struct pt_regs *regs)
205 {
206 u32 stat, irq;
207 int handled = 0;
208
209 while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) {
210 irq = ffs(stat) - 1;
211 handle_domain_irq(vic->domain, irq, regs);
212 handled = 1;
213 }
214
215 return handled;
216 }
217
vic_handle_irq_cascaded(struct irq_desc * desc)218 static void vic_handle_irq_cascaded(struct irq_desc *desc)
219 {
220 u32 stat, hwirq;
221 struct irq_chip *host_chip = irq_desc_get_chip(desc);
222 struct vic_device *vic = irq_desc_get_handler_data(desc);
223
224 chained_irq_enter(host_chip, desc);
225
226 while ((stat = readl_relaxed(vic->base + VIC_IRQ_STATUS))) {
227 hwirq = ffs(stat) - 1;
228 generic_handle_irq(irq_find_mapping(vic->domain, hwirq));
229 }
230
231 chained_irq_exit(host_chip, desc);
232 }
233
234 /*
235 * Keep iterating over all registered VIC's until there are no pending
236 * interrupts.
237 */
vic_handle_irq(struct pt_regs * regs)238 static void __exception_irq_entry vic_handle_irq(struct pt_regs *regs)
239 {
240 int i, handled;
241
242 do {
243 for (i = 0, handled = 0; i < vic_id; ++i)
244 handled |= handle_one_vic(&vic_devices[i], regs);
245 } while (handled);
246 }
247
248 static const struct irq_domain_ops vic_irqdomain_ops = {
249 .map = vic_irqdomain_map,
250 .xlate = irq_domain_xlate_onetwocell,
251 };
252
253 /**
254 * vic_register() - Register a VIC.
255 * @base: The base address of the VIC.
256 * @parent_irq: The parent IRQ if cascaded, else 0.
257 * @irq: The base IRQ for the VIC.
258 * @valid_sources: bitmask of valid interrupts
259 * @resume_sources: bitmask of interrupts allowed for resume sources.
260 * @node: The device tree node associated with the VIC.
261 *
262 * Register the VIC with the system device tree so that it can be notified
263 * of suspend and resume requests and ensure that the correct actions are
264 * taken to re-instate the settings on resume.
265 *
266 * This also configures the IRQ domain for the VIC.
267 */
vic_register(void __iomem * base,unsigned int parent_irq,unsigned int irq,u32 valid_sources,u32 resume_sources,struct device_node * node)268 static void __init vic_register(void __iomem *base, unsigned int parent_irq,
269 unsigned int irq,
270 u32 valid_sources, u32 resume_sources,
271 struct device_node *node)
272 {
273 struct vic_device *v;
274 int i;
275
276 if (vic_id >= ARRAY_SIZE(vic_devices)) {
277 printk(KERN_ERR "%s: too few VICs, increase CONFIG_ARM_VIC_NR\n", __func__);
278 return;
279 }
280
281 v = &vic_devices[vic_id];
282 v->base = base;
283 v->valid_sources = valid_sources;
284 v->resume_sources = resume_sources;
285 set_handle_irq(vic_handle_irq);
286 vic_id++;
287
288 if (parent_irq) {
289 irq_set_chained_handler_and_data(parent_irq,
290 vic_handle_irq_cascaded, v);
291 }
292
293 v->domain = irq_domain_add_simple(node, fls(valid_sources), irq,
294 &vic_irqdomain_ops, v);
295 /* create an IRQ mapping for each valid IRQ */
296 for (i = 0; i < fls(valid_sources); i++)
297 if (valid_sources & (1 << i))
298 irq_create_mapping(v->domain, i);
299 /* If no base IRQ was passed, figure out our allocated base */
300 if (irq)
301 v->irq = irq;
302 else
303 v->irq = irq_find_mapping(v->domain, 0);
304 }
305
vic_ack_irq(struct irq_data * d)306 static void vic_ack_irq(struct irq_data *d)
307 {
308 void __iomem *base = irq_data_get_irq_chip_data(d);
309 unsigned int irq = d->hwirq;
310 writel(1 << irq, base + VIC_INT_ENABLE_CLEAR);
311 /* moreover, clear the soft-triggered, in case it was the reason */
312 writel(1 << irq, base + VIC_INT_SOFT_CLEAR);
313 }
314
vic_mask_irq(struct irq_data * d)315 static void vic_mask_irq(struct irq_data *d)
316 {
317 void __iomem *base = irq_data_get_irq_chip_data(d);
318 unsigned int irq = d->hwirq;
319 writel(1 << irq, base + VIC_INT_ENABLE_CLEAR);
320 }
321
vic_unmask_irq(struct irq_data * d)322 static void vic_unmask_irq(struct irq_data *d)
323 {
324 void __iomem *base = irq_data_get_irq_chip_data(d);
325 unsigned int irq = d->hwirq;
326 writel(1 << irq, base + VIC_INT_ENABLE);
327 }
328
329 #if defined(CONFIG_PM)
vic_from_irq(unsigned int irq)330 static struct vic_device *vic_from_irq(unsigned int irq)
331 {
332 struct vic_device *v = vic_devices;
333 unsigned int base_irq = irq & ~31;
334 int id;
335
336 for (id = 0; id < vic_id; id++, v++) {
337 if (v->irq == base_irq)
338 return v;
339 }
340
341 return NULL;
342 }
343
vic_set_wake(struct irq_data * d,unsigned int on)344 static int vic_set_wake(struct irq_data *d, unsigned int on)
345 {
346 struct vic_device *v = vic_from_irq(d->irq);
347 unsigned int off = d->hwirq;
348 u32 bit = 1 << off;
349
350 if (!v)
351 return -EINVAL;
352
353 if (!(bit & v->resume_sources))
354 return -EINVAL;
355
356 if (on)
357 v->resume_irqs |= bit;
358 else
359 v->resume_irqs &= ~bit;
360
361 return 0;
362 }
363 #else
364 #define vic_set_wake NULL
365 #endif /* CONFIG_PM */
366
367 static struct irq_chip vic_chip = {
368 .name = "VIC",
369 .irq_ack = vic_ack_irq,
370 .irq_mask = vic_mask_irq,
371 .irq_unmask = vic_unmask_irq,
372 .irq_set_wake = vic_set_wake,
373 };
374
vic_disable(void __iomem * base)375 static void __init vic_disable(void __iomem *base)
376 {
377 writel(0, base + VIC_INT_SELECT);
378 writel(0, base + VIC_INT_ENABLE);
379 writel(~0, base + VIC_INT_ENABLE_CLEAR);
380 writel(0, base + VIC_ITCR);
381 writel(~0, base + VIC_INT_SOFT_CLEAR);
382 }
383
vic_clear_interrupts(void __iomem * base)384 static void __init vic_clear_interrupts(void __iomem *base)
385 {
386 unsigned int i;
387
388 writel(0, base + VIC_PL190_VECT_ADDR);
389 for (i = 0; i < 19; i++) {
390 unsigned int value;
391
392 value = readl(base + VIC_PL190_VECT_ADDR);
393 writel(value, base + VIC_PL190_VECT_ADDR);
394 }
395 }
396
397 /*
398 * The PL190 cell from ARM has been modified by ST to handle 64 interrupts.
399 * The original cell has 32 interrupts, while the modified one has 64,
400 * replicating two blocks 0x00..0x1f in 0x20..0x3f. In that case
401 * the probe function is called twice, with base set to offset 000
402 * and 020 within the page. We call this "second block".
403 */
vic_init_st(void __iomem * base,unsigned int irq_start,u32 vic_sources,struct device_node * node)404 static void __init vic_init_st(void __iomem *base, unsigned int irq_start,
405 u32 vic_sources, struct device_node *node)
406 {
407 unsigned int i;
408 int vic_2nd_block = ((unsigned long)base & ~PAGE_MASK) != 0;
409
410 /* Disable all interrupts initially. */
411 vic_disable(base);
412
413 /*
414 * Make sure we clear all existing interrupts. The vector registers
415 * in this cell are after the second block of general registers,
416 * so we can address them using standard offsets, but only from
417 * the second base address, which is 0x20 in the page
418 */
419 if (vic_2nd_block) {
420 vic_clear_interrupts(base);
421
422 /* ST has 16 vectors as well, but we don't enable them by now */
423 for (i = 0; i < 16; i++) {
424 void __iomem *reg = base + VIC_VECT_CNTL0 + (i * 4);
425 writel(0, reg);
426 }
427
428 writel(32, base + VIC_PL190_DEF_VECT_ADDR);
429 }
430
431 vic_register(base, 0, irq_start, vic_sources, 0, node);
432 }
433
__vic_init(void __iomem * base,int parent_irq,int irq_start,u32 vic_sources,u32 resume_sources,struct device_node * node)434 static void __init __vic_init(void __iomem *base, int parent_irq, int irq_start,
435 u32 vic_sources, u32 resume_sources,
436 struct device_node *node)
437 {
438 unsigned int i;
439 u32 cellid = 0;
440 enum amba_vendor vendor;
441
442 /* Identify which VIC cell this one is, by reading the ID */
443 for (i = 0; i < 4; i++) {
444 void __iomem *addr;
445 addr = (void __iomem *)((u32)base & PAGE_MASK) + 0xfe0 + (i * 4);
446 cellid |= (readl(addr) & 0xff) << (8 * i);
447 }
448 vendor = (cellid >> 12) & 0xff;
449 printk(KERN_INFO "VIC @%p: id 0x%08x, vendor 0x%02x\n",
450 base, cellid, vendor);
451
452 switch(vendor) {
453 case AMBA_VENDOR_ST:
454 vic_init_st(base, irq_start, vic_sources, node);
455 return;
456 default:
457 printk(KERN_WARNING "VIC: unknown vendor, continuing anyways\n");
458 fallthrough;
459 case AMBA_VENDOR_ARM:
460 break;
461 }
462
463 /* Disable all interrupts initially. */
464 vic_disable(base);
465
466 /* Make sure we clear all existing interrupts */
467 vic_clear_interrupts(base);
468
469 vic_init2(base);
470
471 vic_register(base, parent_irq, irq_start, vic_sources, resume_sources, node);
472 }
473
474 /**
475 * vic_init() - initialise a vectored interrupt controller
476 * @base: iomem base address
477 * @irq_start: starting interrupt number, must be muliple of 32
478 * @vic_sources: bitmask of interrupt sources to allow
479 * @resume_sources: bitmask of interrupt sources to allow for resume
480 */
vic_init(void __iomem * base,unsigned int irq_start,u32 vic_sources,u32 resume_sources)481 void __init vic_init(void __iomem *base, unsigned int irq_start,
482 u32 vic_sources, u32 resume_sources)
483 {
484 __vic_init(base, 0, irq_start, vic_sources, resume_sources, NULL);
485 }
486
487 #ifdef CONFIG_OF
vic_of_init(struct device_node * node,struct device_node * parent)488 static int __init vic_of_init(struct device_node *node,
489 struct device_node *parent)
490 {
491 void __iomem *regs;
492 u32 interrupt_mask = ~0;
493 u32 wakeup_mask = ~0;
494 int parent_irq;
495
496 regs = of_iomap(node, 0);
497 if (WARN_ON(!regs))
498 return -EIO;
499
500 of_property_read_u32(node, "valid-mask", &interrupt_mask);
501 of_property_read_u32(node, "valid-wakeup-mask", &wakeup_mask);
502 parent_irq = of_irq_get(node, 0);
503 if (parent_irq < 0)
504 parent_irq = 0;
505
506 /*
507 * Passing 0 as first IRQ makes the simple domain allocate descriptors
508 */
509 __vic_init(regs, parent_irq, 0, interrupt_mask, wakeup_mask, node);
510
511 return 0;
512 }
513 IRQCHIP_DECLARE(arm_pl190_vic, "arm,pl190-vic", vic_of_init);
514 IRQCHIP_DECLARE(arm_pl192_vic, "arm,pl192-vic", vic_of_init);
515 IRQCHIP_DECLARE(arm_versatile_vic, "arm,versatile-vic", vic_of_init);
516 #endif /* CONFIG OF */
517