xref: /linux/drivers/irqchip/irq-bcm7038-l1.c (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Broadcom BCM7038 style Level 1 interrupt controller driver
4  *
5  * Copyright (C) 2014 Broadcom Corporation
6  * Author: Kevin Cernekee
7  */
8 
9 #define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt
10 
11 #include <linux/bitops.h>
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/ioport.h>
17 #include <linux/irq.h>
18 #include <linux/irqdomain.h>
19 #include <linux/module.h>
20 #include <linux/of.h>
21 #include <linux/of_irq.h>
22 #include <linux/of_address.h>
23 #include <linux/platform_device.h>
24 #include <linux/slab.h>
25 #include <linux/smp.h>
26 #include <linux/types.h>
27 #include <linux/irqchip.h>
28 #include <linux/irqchip/chained_irq.h>
29 #include <linux/syscore_ops.h>
30 
31 #define IRQS_PER_WORD		32
32 #define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 4)
33 #define MAX_WORDS		8
34 
35 struct bcm7038_l1_cpu;
36 
37 struct bcm7038_l1_chip {
38 	raw_spinlock_t		lock;
39 	unsigned int		n_words;
40 	struct irq_domain	*domain;
41 	struct bcm7038_l1_cpu	*cpus[NR_CPUS];
42 #ifdef CONFIG_PM_SLEEP
43 	struct list_head	list;
44 	u32			wake_mask[MAX_WORDS];
45 #endif
46 	u32			irq_fwd_mask[MAX_WORDS];
47 	u8			affinity[MAX_WORDS * IRQS_PER_WORD];
48 };
49 
50 struct bcm7038_l1_cpu {
51 	void __iomem		*map_base;
52 	u32			mask_cache[];
53 };
54 
55 /*
56  * STATUS/MASK_STATUS/MASK_SET/MASK_CLEAR are packed one right after another:
57  *
58  * 7038:
59  *   0x1000_1400: W0_STATUS
60  *   0x1000_1404: W1_STATUS
61  *   0x1000_1408: W0_MASK_STATUS
62  *   0x1000_140c: W1_MASK_STATUS
63  *   0x1000_1410: W0_MASK_SET
64  *   0x1000_1414: W1_MASK_SET
65  *   0x1000_1418: W0_MASK_CLEAR
66  *   0x1000_141c: W1_MASK_CLEAR
67  *
68  * 7445:
69  *   0xf03e_1500: W0_STATUS
70  *   0xf03e_1504: W1_STATUS
71  *   0xf03e_1508: W2_STATUS
72  *   0xf03e_150c: W3_STATUS
73  *   0xf03e_1510: W4_STATUS
74  *   0xf03e_1514: W0_MASK_STATUS
75  *   0xf03e_1518: W1_MASK_STATUS
76  *   [...]
77  */
78 
79 static inline unsigned int reg_status(struct bcm7038_l1_chip *intc,
80 				      unsigned int word)
81 {
82 	return (0 * intc->n_words + word) * sizeof(u32);
83 }
84 
85 static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
86 					unsigned int word)
87 {
88 	return (2 * intc->n_words + word) * sizeof(u32);
89 }
90 
91 static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
92 					unsigned int word)
93 {
94 	return (3 * intc->n_words + word) * sizeof(u32);
95 }
96 
97 static inline u32 l1_readl(void __iomem *reg)
98 {
99 	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
100 		return ioread32be(reg);
101 	else
102 		return readl(reg);
103 }
104 
105 static inline void l1_writel(u32 val, void __iomem *reg)
106 {
107 	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
108 		iowrite32be(val, reg);
109 	else
110 		writel(val, reg);
111 }
112 
113 static void bcm7038_l1_irq_handle(struct irq_desc *desc)
114 {
115 	struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
116 	struct bcm7038_l1_cpu *cpu;
117 	struct irq_chip *chip = irq_desc_get_chip(desc);
118 	unsigned int idx;
119 
120 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
121 	cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
122 #else
123 	cpu = intc->cpus[0];
124 #endif
125 
126 	chained_irq_enter(chip, desc);
127 
128 	for (idx = 0; idx < intc->n_words; idx++) {
129 		int base = idx * IRQS_PER_WORD;
130 		unsigned long pending, flags;
131 		int hwirq;
132 
133 		raw_spin_lock_irqsave(&intc->lock, flags);
134 		pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
135 			  ~cpu->mask_cache[idx];
136 		raw_spin_unlock_irqrestore(&intc->lock, flags);
137 
138 		for_each_set_bit(hwirq, &pending, IRQS_PER_WORD)
139 			generic_handle_domain_irq(intc->domain, base + hwirq);
140 	}
141 
142 	chained_irq_exit(chip, desc);
143 }
144 
145 static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
146 {
147 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
148 	u32 word = d->hwirq / IRQS_PER_WORD;
149 	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
150 
151 	intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
152 	l1_writel(mask, intc->cpus[cpu_idx]->map_base +
153 			reg_mask_clr(intc, word));
154 }
155 
156 static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
157 {
158 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
159 	u32 word = d->hwirq / IRQS_PER_WORD;
160 	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
161 
162 	intc->cpus[cpu_idx]->mask_cache[word] |= mask;
163 	l1_writel(mask, intc->cpus[cpu_idx]->map_base +
164 			reg_mask_set(intc, word));
165 }
166 
167 static void bcm7038_l1_unmask(struct irq_data *d)
168 {
169 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
170 	unsigned long flags;
171 
172 	raw_spin_lock_irqsave(&intc->lock, flags);
173 	__bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
174 	raw_spin_unlock_irqrestore(&intc->lock, flags);
175 }
176 
177 static void bcm7038_l1_mask(struct irq_data *d)
178 {
179 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
180 	unsigned long flags;
181 
182 	raw_spin_lock_irqsave(&intc->lock, flags);
183 	__bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
184 	raw_spin_unlock_irqrestore(&intc->lock, flags);
185 }
186 
187 #if defined(CONFIG_MIPS) && defined(CONFIG_SMP)
188 static int bcm7038_l1_set_affinity(struct irq_data *d,
189 				   const struct cpumask *dest,
190 				   bool force)
191 {
192 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
193 	unsigned long flags;
194 	irq_hw_number_t hw = d->hwirq;
195 	u32 word = hw / IRQS_PER_WORD;
196 	u32 mask = BIT(hw % IRQS_PER_WORD);
197 	unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
198 	bool was_disabled;
199 
200 	raw_spin_lock_irqsave(&intc->lock, flags);
201 
202 	was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
203 			  mask);
204 	__bcm7038_l1_mask(d, intc->affinity[hw]);
205 	intc->affinity[hw] = first_cpu;
206 	if (!was_disabled)
207 		__bcm7038_l1_unmask(d, first_cpu);
208 
209 	raw_spin_unlock_irqrestore(&intc->lock, flags);
210 	irq_data_update_effective_affinity(d, cpumask_of(first_cpu));
211 
212 	return 0;
213 }
214 #endif
215 
216 static int bcm7038_l1_init_one(struct device_node *dn, unsigned int idx,
217 			       struct bcm7038_l1_chip *intc)
218 {
219 	struct resource res;
220 	resource_size_t sz;
221 	struct bcm7038_l1_cpu *cpu;
222 	unsigned int i, n_words, parent_irq;
223 	int ret;
224 
225 	if (of_address_to_resource(dn, idx, &res))
226 		return -EINVAL;
227 	sz = resource_size(&res);
228 	n_words = sz / REG_BYTES_PER_IRQ_WORD;
229 
230 	if (n_words > MAX_WORDS)
231 		return -EINVAL;
232 	else if (!intc->n_words)
233 		intc->n_words = n_words;
234 	else if (intc->n_words != n_words)
235 		return -EINVAL;
236 
237 	ret = of_property_read_u32_array(dn , "brcm,int-fwd-mask",
238 					 intc->irq_fwd_mask, n_words);
239 	if (ret != 0 && ret != -EINVAL) {
240 		/* property exists but has the wrong number of words */
241 		pr_err("invalid brcm,int-fwd-mask property\n");
242 		return -EINVAL;
243 	}
244 
245 	cpu = intc->cpus[idx] = kzalloc(struct_size(cpu, mask_cache, n_words),
246 					GFP_KERNEL);
247 	if (!cpu)
248 		return -ENOMEM;
249 
250 	cpu->map_base = ioremap(res.start, sz);
251 	if (!cpu->map_base)
252 		return -ENOMEM;
253 
254 	for (i = 0; i < n_words; i++) {
255 		l1_writel(~intc->irq_fwd_mask[i],
256 			  cpu->map_base + reg_mask_set(intc, i));
257 		l1_writel(intc->irq_fwd_mask[i],
258 			  cpu->map_base + reg_mask_clr(intc, i));
259 		cpu->mask_cache[i] = ~intc->irq_fwd_mask[i];
260 	}
261 
262 	parent_irq = irq_of_parse_and_map(dn, idx);
263 	if (!parent_irq) {
264 		pr_err("failed to map parent interrupt %d\n", parent_irq);
265 		return -EINVAL;
266 	}
267 
268 	if (of_property_read_bool(dn, "brcm,irq-can-wake"))
269 		enable_irq_wake(parent_irq);
270 
271 	irq_set_chained_handler_and_data(parent_irq, bcm7038_l1_irq_handle,
272 					 intc);
273 
274 	return 0;
275 }
276 
277 #ifdef CONFIG_PM_SLEEP
278 /*
279  * We keep a list of bcm7038_l1_chip used for suspend/resume. This hack is
280  * used because the struct chip_type suspend/resume hooks are not called
281  * unless chip_type is hooked onto a generic_chip. Since this driver does
282  * not use generic_chip, we need to manually hook our resume/suspend to
283  * syscore_ops.
284  */
285 static LIST_HEAD(bcm7038_l1_intcs_list);
286 static DEFINE_RAW_SPINLOCK(bcm7038_l1_intcs_lock);
287 
288 static int bcm7038_l1_suspend(void)
289 {
290 	struct bcm7038_l1_chip *intc;
291 	int boot_cpu, word;
292 	u32 val;
293 
294 	/* Wakeup interrupt should only come from the boot cpu */
295 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
296 	boot_cpu = cpu_logical_map(0);
297 #else
298 	boot_cpu = 0;
299 #endif
300 
301 	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
302 		for (word = 0; word < intc->n_words; word++) {
303 			val = intc->wake_mask[word] | intc->irq_fwd_mask[word];
304 			l1_writel(~val,
305 				intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
306 			l1_writel(val,
307 				intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
308 		}
309 	}
310 
311 	return 0;
312 }
313 
314 static void bcm7038_l1_resume(void)
315 {
316 	struct bcm7038_l1_chip *intc;
317 	int boot_cpu, word;
318 
319 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
320 	boot_cpu = cpu_logical_map(0);
321 #else
322 	boot_cpu = 0;
323 #endif
324 
325 	list_for_each_entry(intc, &bcm7038_l1_intcs_list, list) {
326 		for (word = 0; word < intc->n_words; word++) {
327 			l1_writel(intc->cpus[boot_cpu]->mask_cache[word],
328 				intc->cpus[boot_cpu]->map_base + reg_mask_set(intc, word));
329 			l1_writel(~intc->cpus[boot_cpu]->mask_cache[word],
330 				intc->cpus[boot_cpu]->map_base + reg_mask_clr(intc, word));
331 		}
332 	}
333 }
334 
335 static struct syscore_ops bcm7038_l1_syscore_ops = {
336 	.suspend	= bcm7038_l1_suspend,
337 	.resume		= bcm7038_l1_resume,
338 };
339 
340 static int bcm7038_l1_set_wake(struct irq_data *d, unsigned int on)
341 {
342 	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
343 	unsigned long flags;
344 	u32 word = d->hwirq / IRQS_PER_WORD;
345 	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
346 
347 	raw_spin_lock_irqsave(&intc->lock, flags);
348 	if (on)
349 		intc->wake_mask[word] |= mask;
350 	else
351 		intc->wake_mask[word] &= ~mask;
352 	raw_spin_unlock_irqrestore(&intc->lock, flags);
353 
354 	return 0;
355 }
356 #endif
357 
358 static struct irq_chip bcm7038_l1_irq_chip = {
359 	.name			= "bcm7038-l1",
360 	.irq_mask		= bcm7038_l1_mask,
361 	.irq_unmask		= bcm7038_l1_unmask,
362 #if defined(CONFIG_SMP) && defined(CONFIG_MIPS)
363 	.irq_set_affinity	= bcm7038_l1_set_affinity,
364 #endif
365 #ifdef CONFIG_PM_SLEEP
366 	.irq_set_wake		= bcm7038_l1_set_wake,
367 #endif
368 };
369 
370 static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
371 			  irq_hw_number_t hw_irq)
372 {
373 	struct bcm7038_l1_chip *intc = d->host_data;
374 	u32 mask = BIT(hw_irq % IRQS_PER_WORD);
375 	u32 word = hw_irq / IRQS_PER_WORD;
376 
377 	if (intc->irq_fwd_mask[word] & mask)
378 		return -EPERM;
379 
380 	irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
381 	irq_set_chip_data(virq, d->host_data);
382 	irqd_set_single_target(irq_get_irq_data(virq));
383 	return 0;
384 }
385 
386 static const struct irq_domain_ops bcm7038_l1_domain_ops = {
387 	.xlate			= irq_domain_xlate_onecell,
388 	.map			= bcm7038_l1_map,
389 };
390 
391 static int bcm7038_l1_probe(struct platform_device *pdev, struct device_node *parent)
392 {
393 	struct device_node *dn = pdev->dev.of_node;
394 	struct bcm7038_l1_chip *intc;
395 	int idx, ret;
396 
397 	intc = kzalloc(sizeof(*intc), GFP_KERNEL);
398 	if (!intc)
399 		return -ENOMEM;
400 
401 	raw_spin_lock_init(&intc->lock);
402 	for_each_possible_cpu(idx) {
403 		ret = bcm7038_l1_init_one(dn, idx, intc);
404 		if (ret < 0) {
405 			if (idx)
406 				break;
407 			pr_err("failed to remap intc L1 registers\n");
408 			goto out_free;
409 		}
410 	}
411 
412 	intc->domain = irq_domain_create_linear(of_fwnode_handle(dn), IRQS_PER_WORD * intc->n_words,
413 					     &bcm7038_l1_domain_ops,
414 					     intc);
415 	if (!intc->domain) {
416 		ret = -ENOMEM;
417 		goto out_unmap;
418 	}
419 
420 #ifdef CONFIG_PM_SLEEP
421 	/* Add bcm7038_l1_chip into a list */
422 	raw_spin_lock(&bcm7038_l1_intcs_lock);
423 	list_add_tail(&intc->list, &bcm7038_l1_intcs_list);
424 	raw_spin_unlock(&bcm7038_l1_intcs_lock);
425 
426 	if (list_is_singular(&bcm7038_l1_intcs_list))
427 		register_syscore_ops(&bcm7038_l1_syscore_ops);
428 #endif
429 
430 	pr_info("registered BCM7038 L1 intc (%pOF, IRQs: %d)\n",
431 		dn, IRQS_PER_WORD * intc->n_words);
432 
433 	return 0;
434 
435 out_unmap:
436 	for_each_possible_cpu(idx) {
437 		struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
438 
439 		if (cpu) {
440 			if (cpu->map_base)
441 				iounmap(cpu->map_base);
442 			kfree(cpu);
443 		}
444 	}
445 out_free:
446 	kfree(intc);
447 	return ret;
448 }
449 
450 IRQCHIP_PLATFORM_DRIVER_BEGIN(bcm7038_l1)
451 IRQCHIP_MATCH("brcm,bcm7038-l1-intc", bcm7038_l1_probe)
452 IRQCHIP_PLATFORM_DRIVER_END(bcm7038_l1)
453 MODULE_DESCRIPTION("Broadcom STB 7038-style L1/L2 interrupt controller");
454 MODULE_LICENSE("GPL v2");
455