1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Broadcom BCM7120 style Level 2 interrupt controller driver
4 *
5 * Copyright (C) 2014 Broadcom Corporation
6 */
7
8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9
10#include <linux/init.h>
11#include <linux/slab.h>
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/platform_device.h>
15#include <linux/of.h>
16#include <linux/of_irq.h>
17#include <linux/of_address.h>
18#include <linux/of_platform.h>
19#include <linux/interrupt.h>
20#include <linux/irq.h>
21#include <linux/io.h>
22#include <linux/irqdomain.h>
23#include <linux/reboot.h>
24#include <linux/bitops.h>
25#include <linux/irqchip.h>
26#include <linux/irqchip/chained_irq.h>
27
28/* Register offset in the L2 interrupt controller */
29#define IRQEN 0x00
30#define IRQSTAT 0x04
31
32#define MAX_WORDS 4
33#define MAX_MAPPINGS (MAX_WORDS * 2)
34#define IRQS_PER_WORD 32
35
36struct bcm7120_l1_intc_data {
37 struct bcm7120_l2_intc_data *b;
38 u32 irq_map_mask[MAX_WORDS];
39};
40
41struct bcm7120_l2_intc_data {
42 unsigned int n_words;
43 void __iomem *map_base[MAX_MAPPINGS];
44 void __iomem *pair_base[MAX_WORDS];
45 int en_offset[MAX_WORDS];
46 int stat_offset[MAX_WORDS];
47 struct irq_domain *domain;
48 bool can_wake;
49 u32 irq_fwd_mask[MAX_WORDS];
50 struct bcm7120_l1_intc_data *l1_data;
51 int num_parent_irqs;
52 const __be32 *map_mask_prop;
53};
54
55static void bcm7120_l2_intc_irq_handle(struct irq_desc *desc)
56{
57 struct bcm7120_l1_intc_data *data = irq_desc_get_handler_data(desc);
58 struct bcm7120_l2_intc_data *b = data->b;
59 struct irq_chip *chip = irq_desc_get_chip(desc);
60 unsigned int idx;
61
62 chained_irq_enter(chip, desc);
63
64 for (idx = 0; idx < b->n_words; idx++) {
65 int base = idx * IRQS_PER_WORD;
66 struct irq_chip_generic *gc =
67 irq_get_domain_generic_chip(d: b->domain, hw_irq: base);
68 unsigned long pending;
69 int hwirq;
70
71 irq_gc_lock(gc);
72 pending = irq_reg_readl(gc, reg_offset: b->stat_offset[idx]) &
73 gc->mask_cache &
74 data->irq_map_mask[idx];
75 irq_gc_unlock(gc);
76
77 for_each_set_bit(hwirq, &pending, IRQS_PER_WORD)
78 generic_handle_domain_irq(domain: b->domain, hwirq: base + hwirq);
79 }
80
81 chained_irq_exit(chip, desc);
82}
83
84static void bcm7120_l2_intc_suspend(struct irq_chip_generic *gc)
85{
86 struct bcm7120_l2_intc_data *b = gc->private;
87 struct irq_chip_type *ct = gc->chip_types;
88
89 irq_gc_lock(gc);
90 if (b->can_wake)
91 irq_reg_writel(gc, val: gc->mask_cache | gc->wake_active,
92 reg_offset: ct->regs.mask);
93 irq_gc_unlock(gc);
94}
95
96static void bcm7120_l2_intc_resume(struct irq_chip_generic *gc)
97{
98 struct irq_chip_type *ct = gc->chip_types;
99
100 /* Restore the saved mask */
101 irq_gc_lock(gc);
102 irq_reg_writel(gc, val: gc->mask_cache, reg_offset: ct->regs.mask);
103 irq_gc_unlock(gc);
104}
105
106static int bcm7120_l2_intc_init_one(struct device_node *dn,
107 struct bcm7120_l2_intc_data *data,
108 int irq, u32 *valid_mask)
109{
110 struct bcm7120_l1_intc_data *l1_data = &data->l1_data[irq];
111 int parent_irq;
112 unsigned int idx;
113
114 parent_irq = irq_of_parse_and_map(node: dn, index: irq);
115 if (!parent_irq) {
116 pr_err("failed to map interrupt %d\n", irq);
117 return -EINVAL;
118 }
119
120 /* For multiple parent IRQs with multiple words, this looks like:
121 * <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...>
122 *
123 * We need to associate a given parent interrupt with its corresponding
124 * map_mask in order to mask the status register with it because we
125 * have the same handler being called for multiple parent interrupts.
126 *
127 * This is typically something needed on BCM7xxx (STB chips).
128 */
129 for (idx = 0; idx < data->n_words; idx++) {
130 if (data->map_mask_prop) {
131 l1_data->irq_map_mask[idx] |=
132 be32_to_cpup(p: data->map_mask_prop +
133 irq * data->n_words + idx);
134 } else {
135 l1_data->irq_map_mask[idx] = 0xffffffff;
136 }
137 valid_mask[idx] |= l1_data->irq_map_mask[idx];
138 }
139
140 l1_data->b = data;
141
142 irq_set_chained_handler_and_data(irq: parent_irq,
143 handle: bcm7120_l2_intc_irq_handle, data: l1_data);
144 if (data->can_wake)
145 enable_irq_wake(irq: parent_irq);
146
147 return 0;
148}
149
150static int __init bcm7120_l2_intc_iomap_7120(struct device_node *dn,
151 struct bcm7120_l2_intc_data *data)
152{
153 int ret;
154
155 data->map_base[0] = of_iomap(node: dn, index: 0);
156 if (!data->map_base[0]) {
157 pr_err("unable to map registers\n");
158 return -ENOMEM;
159 }
160
161 data->pair_base[0] = data->map_base[0];
162 data->en_offset[0] = IRQEN;
163 data->stat_offset[0] = IRQSTAT;
164 data->n_words = 1;
165
166 ret = of_property_read_u32_array(np: dn, propname: "brcm,int-fwd-mask",
167 out_values: data->irq_fwd_mask, sz: data->n_words);
168 if (ret != 0 && ret != -EINVAL) {
169 /* property exists but has the wrong number of words */
170 pr_err("invalid brcm,int-fwd-mask property\n");
171 return -EINVAL;
172 }
173
174 data->map_mask_prop = of_get_property(node: dn, name: "brcm,int-map-mask", lenp: &ret);
175 if (!data->map_mask_prop ||
176 (ret != (sizeof(__be32) * data->num_parent_irqs * data->n_words))) {
177 pr_err("invalid brcm,int-map-mask property\n");
178 return -EINVAL;
179 }
180
181 return 0;
182}
183
184static int __init bcm7120_l2_intc_iomap_3380(struct device_node *dn,
185 struct bcm7120_l2_intc_data *data)
186{
187 unsigned int gc_idx;
188
189 for (gc_idx = 0; gc_idx < MAX_WORDS; gc_idx++) {
190 unsigned int map_idx = gc_idx * 2;
191 void __iomem *en = of_iomap(node: dn, index: map_idx + 0);
192 void __iomem *stat = of_iomap(node: dn, index: map_idx + 1);
193 void __iomem *base = min(en, stat);
194
195 data->map_base[map_idx + 0] = en;
196 data->map_base[map_idx + 1] = stat;
197
198 if (!base)
199 break;
200
201 data->pair_base[gc_idx] = base;
202 data->en_offset[gc_idx] = en - base;
203 data->stat_offset[gc_idx] = stat - base;
204 }
205
206 if (!gc_idx) {
207 pr_err("unable to map registers\n");
208 return -EINVAL;
209 }
210
211 data->n_words = gc_idx;
212 return 0;
213}
214
215static int __init bcm7120_l2_intc_probe(struct device_node *dn,
216 struct device_node *parent,
217 int (*iomap_regs_fn)(struct device_node *,
218 struct bcm7120_l2_intc_data *),
219 const char *intc_name)
220{
221 unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
222 struct bcm7120_l2_intc_data *data;
223 struct platform_device *pdev;
224 struct irq_chip_generic *gc;
225 struct irq_chip_type *ct;
226 int ret = 0;
227 unsigned int idx, irq, flags;
228 u32 valid_mask[MAX_WORDS] = { };
229
230 data = kzalloc(size: sizeof(*data), GFP_KERNEL);
231 if (!data)
232 return -ENOMEM;
233
234 pdev = of_find_device_by_node(np: dn);
235 if (!pdev) {
236 ret = -ENODEV;
237 goto out_free_data;
238 }
239
240 data->num_parent_irqs = platform_irq_count(pdev);
241 put_device(dev: &pdev->dev);
242 if (data->num_parent_irqs <= 0) {
243 pr_err("invalid number of parent interrupts\n");
244 ret = -ENOMEM;
245 goto out_unmap;
246 }
247
248 data->l1_data = kcalloc(n: data->num_parent_irqs, size: sizeof(*data->l1_data),
249 GFP_KERNEL);
250 if (!data->l1_data) {
251 ret = -ENOMEM;
252 goto out_free_l1_data;
253 }
254
255 ret = iomap_regs_fn(dn, data);
256 if (ret < 0)
257 goto out_free_l1_data;
258
259 data->can_wake = of_property_read_bool(np: dn, propname: "brcm,irq-can-wake");
260
261 for (irq = 0; irq < data->num_parent_irqs; irq++) {
262 ret = bcm7120_l2_intc_init_one(dn, data, irq, valid_mask);
263 if (ret)
264 goto out_free_l1_data;
265 }
266
267 data->domain = irq_domain_add_linear(of_node: dn, IRQS_PER_WORD * data->n_words,
268 ops: &irq_generic_chip_ops, NULL);
269 if (!data->domain) {
270 ret = -ENOMEM;
271 goto out_free_l1_data;
272 }
273
274 /* MIPS chips strapped for BE will automagically configure the
275 * peripheral registers for CPU-native byte order.
276 */
277 flags = IRQ_GC_INIT_MASK_CACHE;
278 if (IS_ENABLED(CONFIG_MIPS) && IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
279 flags |= IRQ_GC_BE_IO;
280
281 ret = irq_alloc_domain_generic_chips(data->domain, IRQS_PER_WORD, 1,
282 dn->full_name, handle_level_irq, clr,
283 IRQ_LEVEL, flags);
284 if (ret) {
285 pr_err("failed to allocate generic irq chip\n");
286 goto out_free_domain;
287 }
288
289 for (idx = 0; idx < data->n_words; idx++) {
290 irq = idx * IRQS_PER_WORD;
291 gc = irq_get_domain_generic_chip(d: data->domain, hw_irq: irq);
292
293 gc->unused = 0xffffffff & ~valid_mask[idx];
294 gc->private = data;
295 ct = gc->chip_types;
296
297 gc->reg_base = data->pair_base[idx];
298 ct->regs.mask = data->en_offset[idx];
299
300 /* gc->reg_base is defined and so is gc->writel */
301 irq_reg_writel(gc, val: data->irq_fwd_mask[idx],
302 reg_offset: data->en_offset[idx]);
303
304 ct->chip.irq_mask = irq_gc_mask_clr_bit;
305 ct->chip.irq_unmask = irq_gc_mask_set_bit;
306 ct->chip.irq_ack = irq_gc_noop;
307 gc->suspend = bcm7120_l2_intc_suspend;
308 gc->resume = bcm7120_l2_intc_resume;
309
310 /*
311 * Initialize mask-cache, in case we need it for
312 * saving/restoring fwd mask even w/o any child interrupts
313 * installed
314 */
315 gc->mask_cache = irq_reg_readl(gc, reg_offset: ct->regs.mask);
316
317 if (data->can_wake) {
318 /* This IRQ chip can wake the system, set all
319 * relevant child interrupts in wake_enabled mask
320 */
321 gc->wake_enabled = 0xffffffff;
322 gc->wake_enabled &= ~gc->unused;
323 ct->chip.irq_set_wake = irq_gc_set_wake;
324 }
325 }
326
327 pr_info("registered %s intc (%pOF, parent IRQ(s): %d)\n",
328 intc_name, dn, data->num_parent_irqs);
329
330 return 0;
331
332out_free_domain:
333 irq_domain_remove(host: data->domain);
334out_free_l1_data:
335 kfree(objp: data->l1_data);
336out_unmap:
337 for (idx = 0; idx < MAX_MAPPINGS; idx++) {
338 if (data->map_base[idx])
339 iounmap(addr: data->map_base[idx]);
340 }
341out_free_data:
342 kfree(objp: data);
343 return ret;
344}
345
346static int __init bcm7120_l2_intc_probe_7120(struct device_node *dn,
347 struct device_node *parent)
348{
349 return bcm7120_l2_intc_probe(dn, parent, iomap_regs_fn: bcm7120_l2_intc_iomap_7120,
350 intc_name: "BCM7120 L2");
351}
352
353static int __init bcm7120_l2_intc_probe_3380(struct device_node *dn,
354 struct device_node *parent)
355{
356 return bcm7120_l2_intc_probe(dn, parent, iomap_regs_fn: bcm7120_l2_intc_iomap_3380,
357 intc_name: "BCM3380 L2");
358}
359
360IRQCHIP_PLATFORM_DRIVER_BEGIN(bcm7120_l2)
361IRQCHIP_MATCH("brcm,bcm7120-l2-intc", bcm7120_l2_intc_probe_7120)
362IRQCHIP_MATCH("brcm,bcm3380-l2-intc", bcm7120_l2_intc_probe_3380)
363IRQCHIP_PLATFORM_DRIVER_END(bcm7120_l2)
364MODULE_DESCRIPTION("Broadcom STB 7120-style L2 interrupt controller driver");
365MODULE_LICENSE("GPL v2");
366

source code of linux/drivers/irqchip/irq-bcm7120-l2.c