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 
36 struct bcm7120_l1_intc_data {
37 	struct bcm7120_l2_intc_data *b;
38 	u32 irq_map_mask[MAX_WORDS];
39 };
40 
41 struct 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 
55 static 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(b->domain, base);
68 		unsigned long pending;
69 		int hwirq;
70 
71 		irq_gc_lock(gc);
72 		pending = irq_reg_readl(gc, 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(b->domain, base + hwirq);
79 	}
80 
81 	chained_irq_exit(chip, desc);
82 }
83 
84 static 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, gc->mask_cache | gc->wake_active,
92 			       ct->regs.mask);
93 	irq_gc_unlock(gc);
94 }
95 
96 static 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, gc->mask_cache, ct->regs.mask);
103 	irq_gc_unlock(gc);
104 }
105 
106 static 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(dn, 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(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(parent_irq,
143 					 bcm7120_l2_intc_irq_handle, l1_data);
144 	if (data->can_wake)
145 		enable_irq_wake(parent_irq);
146 
147 	return 0;
148 }
149 
150 static 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(dn, 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(dn, "brcm,int-fwd-mask",
167 					 data->irq_fwd_mask, 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(dn, "brcm,int-map-mask", &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 
184 static 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(dn, map_idx + 0);
192 		void __iomem *stat = of_iomap(dn, 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 
215 static 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(sizeof(*data), GFP_KERNEL);
231 	if (!data)
232 		return -ENOMEM;
233 
234 	pdev = of_find_device_by_node(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(&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(data->num_parent_irqs, 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(dn, "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(dn, IRQS_PER_WORD * data->n_words,
268 					     &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(data->domain, 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, data->irq_fwd_mask[idx],
302 			       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, 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 
332 out_free_domain:
333 	irq_domain_remove(data->domain);
334 out_free_l1_data:
335 	kfree(data->l1_data);
336 out_unmap:
337 	for (idx = 0; idx < MAX_MAPPINGS; idx++) {
338 		if (data->map_base[idx])
339 			iounmap(data->map_base[idx]);
340 	}
341 out_free_data:
342 	kfree(data);
343 	return ret;
344 }
345 
346 static 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, bcm7120_l2_intc_iomap_7120,
350 				     "BCM7120 L2");
351 }
352 
353 static 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, bcm7120_l2_intc_iomap_3380,
357 				     "BCM3380 L2");
358 }
359 
360 IRQCHIP_PLATFORM_DRIVER_BEGIN(bcm7120_l2)
361 IRQCHIP_MATCH("brcm,bcm7120-l2-intc", bcm7120_l2_intc_probe_7120)
362 IRQCHIP_MATCH("brcm,bcm3380-l2-intc", bcm7120_l2_intc_probe_3380)
363 IRQCHIP_PLATFORM_DRIVER_END(bcm7120_l2)
364 MODULE_DESCRIPTION("Broadcom STB 7120-style L2 interrupt controller driver");
365 MODULE_LICENSE("GPL v2");
366