1/*
2 * Broadcom BCM7038 style Level 1 interrupt controller driver
3 *
4 * Copyright (C) 2014 Broadcom Corporation
5 * Author: Kevin Cernekee
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12#define pr_fmt(fmt)	KBUILD_MODNAME	": " fmt
13
14#include <linux/bitops.h>
15#include <linux/kconfig.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/interrupt.h>
19#include <linux/io.h>
20#include <linux/ioport.h>
21#include <linux/irq.h>
22#include <linux/irqdomain.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/of_irq.h>
26#include <linux/of_address.h>
27#include <linux/of_platform.h>
28#include <linux/platform_device.h>
29#include <linux/slab.h>
30#include <linux/smp.h>
31#include <linux/types.h>
32#include <linux/irqchip/chained_irq.h>
33
34#include "irqchip.h"
35
36#define IRQS_PER_WORD		32
37#define REG_BYTES_PER_IRQ_WORD	(sizeof(u32) * 4)
38#define MAX_WORDS		8
39
40struct bcm7038_l1_cpu;
41
42struct bcm7038_l1_chip {
43	raw_spinlock_t		lock;
44	unsigned int		n_words;
45	struct irq_domain	*domain;
46	struct bcm7038_l1_cpu	*cpus[NR_CPUS];
47	u8			affinity[MAX_WORDS * IRQS_PER_WORD];
48};
49
50struct bcm7038_l1_cpu {
51	void __iomem		*map_base;
52	u32			mask_cache[0];
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
79static 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
85static inline unsigned int reg_mask_status(struct bcm7038_l1_chip *intc,
86					   unsigned int word)
87{
88	return (1 * intc->n_words + word) * sizeof(u32);
89}
90
91static inline unsigned int reg_mask_set(struct bcm7038_l1_chip *intc,
92					unsigned int word)
93{
94	return (2 * intc->n_words + word) * sizeof(u32);
95}
96
97static inline unsigned int reg_mask_clr(struct bcm7038_l1_chip *intc,
98					unsigned int word)
99{
100	return (3 * intc->n_words + word) * sizeof(u32);
101}
102
103static inline u32 l1_readl(void __iomem *reg)
104{
105	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
106		return ioread32be(reg);
107	else
108		return readl(reg);
109}
110
111static inline void l1_writel(u32 val, void __iomem *reg)
112{
113	if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
114		iowrite32be(val, reg);
115	else
116		writel(val, reg);
117}
118
119static void bcm7038_l1_irq_handle(unsigned int irq, struct irq_desc *desc)
120{
121	struct bcm7038_l1_chip *intc = irq_desc_get_handler_data(desc);
122	struct bcm7038_l1_cpu *cpu;
123	struct irq_chip *chip = irq_desc_get_chip(desc);
124	unsigned int idx;
125
126#ifdef CONFIG_SMP
127	cpu = intc->cpus[cpu_logical_map(smp_processor_id())];
128#else
129	cpu = intc->cpus[0];
130#endif
131
132	chained_irq_enter(chip, desc);
133
134	for (idx = 0; idx < intc->n_words; idx++) {
135		int base = idx * IRQS_PER_WORD;
136		unsigned long pending, flags;
137		int hwirq;
138
139		raw_spin_lock_irqsave(&intc->lock, flags);
140		pending = l1_readl(cpu->map_base + reg_status(intc, idx)) &
141			  ~cpu->mask_cache[idx];
142		raw_spin_unlock_irqrestore(&intc->lock, flags);
143
144		for_each_set_bit(hwirq, &pending, IRQS_PER_WORD) {
145			generic_handle_irq(irq_find_mapping(intc->domain,
146							    base + hwirq));
147		}
148	}
149
150	chained_irq_exit(chip, desc);
151}
152
153static void __bcm7038_l1_unmask(struct irq_data *d, unsigned int cpu_idx)
154{
155	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
156	u32 word = d->hwirq / IRQS_PER_WORD;
157	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
158
159	intc->cpus[cpu_idx]->mask_cache[word] &= ~mask;
160	l1_writel(mask, intc->cpus[cpu_idx]->map_base +
161			reg_mask_clr(intc, word));
162}
163
164static void __bcm7038_l1_mask(struct irq_data *d, unsigned int cpu_idx)
165{
166	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
167	u32 word = d->hwirq / IRQS_PER_WORD;
168	u32 mask = BIT(d->hwirq % IRQS_PER_WORD);
169
170	intc->cpus[cpu_idx]->mask_cache[word] |= mask;
171	l1_writel(mask, intc->cpus[cpu_idx]->map_base +
172			reg_mask_set(intc, word));
173}
174
175static void bcm7038_l1_unmask(struct irq_data *d)
176{
177	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
178	unsigned long flags;
179
180	raw_spin_lock_irqsave(&intc->lock, flags);
181	__bcm7038_l1_unmask(d, intc->affinity[d->hwirq]);
182	raw_spin_unlock_irqrestore(&intc->lock, flags);
183}
184
185static void bcm7038_l1_mask(struct irq_data *d)
186{
187	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
188	unsigned long flags;
189
190	raw_spin_lock_irqsave(&intc->lock, flags);
191	__bcm7038_l1_mask(d, intc->affinity[d->hwirq]);
192	raw_spin_unlock_irqrestore(&intc->lock, flags);
193}
194
195static int bcm7038_l1_set_affinity(struct irq_data *d,
196				   const struct cpumask *dest,
197				   bool force)
198{
199	struct bcm7038_l1_chip *intc = irq_data_get_irq_chip_data(d);
200	unsigned long flags;
201	irq_hw_number_t hw = d->hwirq;
202	u32 word = hw / IRQS_PER_WORD;
203	u32 mask = BIT(hw % IRQS_PER_WORD);
204	unsigned int first_cpu = cpumask_any_and(dest, cpu_online_mask);
205	bool was_disabled;
206
207	raw_spin_lock_irqsave(&intc->lock, flags);
208
209	was_disabled = !!(intc->cpus[intc->affinity[hw]]->mask_cache[word] &
210			  mask);
211	__bcm7038_l1_mask(d, intc->affinity[hw]);
212	intc->affinity[hw] = first_cpu;
213	if (!was_disabled)
214		__bcm7038_l1_unmask(d, first_cpu);
215
216	raw_spin_unlock_irqrestore(&intc->lock, flags);
217	return 0;
218}
219
220static int __init bcm7038_l1_init_one(struct device_node *dn,
221				      unsigned int idx,
222				      struct bcm7038_l1_chip *intc)
223{
224	struct resource res;
225	resource_size_t sz;
226	struct bcm7038_l1_cpu *cpu;
227	unsigned int i, n_words, parent_irq;
228
229	if (of_address_to_resource(dn, idx, &res))
230		return -EINVAL;
231	sz = resource_size(&res);
232	n_words = sz / REG_BYTES_PER_IRQ_WORD;
233
234	if (n_words > MAX_WORDS)
235		return -EINVAL;
236	else if (!intc->n_words)
237		intc->n_words = n_words;
238	else if (intc->n_words != n_words)
239		return -EINVAL;
240
241	cpu = intc->cpus[idx] = kzalloc(sizeof(*cpu) + n_words * sizeof(u32),
242					GFP_KERNEL);
243	if (!cpu)
244		return -ENOMEM;
245
246	cpu->map_base = ioremap(res.start, sz);
247	if (!cpu->map_base)
248		return -ENOMEM;
249
250	for (i = 0; i < n_words; i++) {
251		l1_writel(0xffffffff, cpu->map_base + reg_mask_set(intc, i));
252		cpu->mask_cache[i] = 0xffffffff;
253	}
254
255	parent_irq = irq_of_parse_and_map(dn, idx);
256	if (!parent_irq) {
257		pr_err("failed to map parent interrupt %d\n", parent_irq);
258		return -EINVAL;
259	}
260	irq_set_handler_data(parent_irq, intc);
261	irq_set_chained_handler(parent_irq, bcm7038_l1_irq_handle);
262
263	return 0;
264}
265
266static struct irq_chip bcm7038_l1_irq_chip = {
267	.name			= "bcm7038-l1",
268	.irq_mask		= bcm7038_l1_mask,
269	.irq_unmask		= bcm7038_l1_unmask,
270	.irq_set_affinity	= bcm7038_l1_set_affinity,
271};
272
273static int bcm7038_l1_map(struct irq_domain *d, unsigned int virq,
274			  irq_hw_number_t hw_irq)
275{
276	irq_set_chip_and_handler(virq, &bcm7038_l1_irq_chip, handle_level_irq);
277	irq_set_chip_data(virq, d->host_data);
278	return 0;
279}
280
281static const struct irq_domain_ops bcm7038_l1_domain_ops = {
282	.xlate			= irq_domain_xlate_onecell,
283	.map			= bcm7038_l1_map,
284};
285
286int __init bcm7038_l1_of_init(struct device_node *dn,
287			      struct device_node *parent)
288{
289	struct bcm7038_l1_chip *intc;
290	int idx, ret;
291
292	intc = kzalloc(sizeof(*intc), GFP_KERNEL);
293	if (!intc)
294		return -ENOMEM;
295
296	raw_spin_lock_init(&intc->lock);
297	for_each_possible_cpu(idx) {
298		ret = bcm7038_l1_init_one(dn, idx, intc);
299		if (ret < 0) {
300			if (idx)
301				break;
302			pr_err("failed to remap intc L1 registers\n");
303			goto out_free;
304		}
305	}
306
307	intc->domain = irq_domain_add_linear(dn, IRQS_PER_WORD * intc->n_words,
308					     &bcm7038_l1_domain_ops,
309					     intc);
310	if (!intc->domain) {
311		ret = -ENOMEM;
312		goto out_unmap;
313	}
314
315	pr_info("registered BCM7038 L1 intc (mem: 0x%p, IRQs: %d)\n",
316		intc->cpus[0]->map_base, IRQS_PER_WORD * intc->n_words);
317
318	return 0;
319
320out_unmap:
321	for_each_possible_cpu(idx) {
322		struct bcm7038_l1_cpu *cpu = intc->cpus[idx];
323
324		if (cpu) {
325			if (cpu->map_base)
326				iounmap(cpu->map_base);
327			kfree(cpu);
328		}
329	}
330out_free:
331	kfree(intc);
332	return ret;
333}
334
335IRQCHIP_DECLARE(bcm7038_l1, "brcm,bcm7038-l1-intc", bcm7038_l1_of_init);
336