xref: /linux/drivers/irqchip/irq-loongson-liointc.c (revision 0e9b70c1e3623fa110fb6be553e644524228ef60)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
4  *  Loongson Local IO Interrupt Controller support
5  */
6 
7 #include <linux/errno.h>
8 #include <linux/init.h>
9 #include <linux/types.h>
10 #include <linux/interrupt.h>
11 #include <linux/ioport.h>
12 #include <linux/irqchip.h>
13 #include <linux/of_address.h>
14 #include <linux/of_irq.h>
15 #include <linux/io.h>
16 #include <linux/smp.h>
17 #include <linux/irqchip/chained_irq.h>
18 
19 #ifdef CONFIG_MIPS
20 #include <loongson.h>
21 #else
22 #include <asm/loongson.h>
23 #endif
24 
25 #define LIOINTC_CHIP_IRQ	32
26 #define LIOINTC_NUM_PARENT	4
27 #define LIOINTC_NUM_CORES	4
28 
29 #define LIOINTC_INTC_CHIP_START	0x20
30 
31 #define LIOINTC_REG_INTC_STATUS	(LIOINTC_INTC_CHIP_START + 0x20)
32 #define LIOINTC_REG_INTC_EN_STATUS	(LIOINTC_INTC_CHIP_START + 0x04)
33 #define LIOINTC_REG_INTC_ENABLE	(LIOINTC_INTC_CHIP_START + 0x08)
34 #define LIOINTC_REG_INTC_DISABLE	(LIOINTC_INTC_CHIP_START + 0x0c)
35 #define LIOINTC_REG_INTC_POL	(LIOINTC_INTC_CHIP_START + 0x10)
36 #define LIOINTC_REG_INTC_EDGE	(LIOINTC_INTC_CHIP_START + 0x14)
37 
38 #define LIOINTC_SHIFT_INTx	4
39 
40 #define LIOINTC_ERRATA_IRQ	10
41 
42 #if defined(CONFIG_MIPS)
43 #define liointc_core_id get_ebase_cpunum()
44 #else
45 #define liointc_core_id get_csr_cpuid()
46 #endif
47 
48 struct liointc_handler_data {
49 	struct liointc_priv	*priv;
50 	u32			parent_int_map;
51 };
52 
53 struct liointc_priv {
54 	struct irq_chip_generic		*gc;
55 	struct liointc_handler_data	handler[LIOINTC_NUM_PARENT];
56 	void __iomem			*core_isr[LIOINTC_NUM_CORES];
57 	u8				map_cache[LIOINTC_CHIP_IRQ];
58 	u32				int_pol;
59 	u32				int_edge;
60 	bool				has_lpc_irq_errata;
61 };
62 
63 struct fwnode_handle *liointc_handle;
64 
65 static void liointc_chained_handle_irq(struct irq_desc *desc)
66 {
67 	struct liointc_handler_data *handler = irq_desc_get_handler_data(desc);
68 	struct irq_chip *chip = irq_desc_get_chip(desc);
69 	struct irq_chip_generic *gc = handler->priv->gc;
70 	int core = liointc_core_id % LIOINTC_NUM_CORES;
71 	u32 pending;
72 
73 	chained_irq_enter(chip, desc);
74 
75 	pending = readl(handler->priv->core_isr[core]);
76 
77 	if (!pending) {
78 		/* Always blame LPC IRQ if we have that bug */
79 		if (handler->priv->has_lpc_irq_errata &&
80 			(handler->parent_int_map & gc->mask_cache &
81 			BIT(LIOINTC_ERRATA_IRQ)))
82 			pending = BIT(LIOINTC_ERRATA_IRQ);
83 		else
84 			spurious_interrupt();
85 	}
86 
87 	while (pending) {
88 		int bit = __ffs(pending);
89 
90 		generic_handle_domain_irq(gc->domain, bit);
91 		pending &= ~BIT(bit);
92 	}
93 
94 	chained_irq_exit(chip, desc);
95 }
96 
97 static void liointc_set_bit(struct irq_chip_generic *gc,
98 				unsigned int offset,
99 				u32 mask, bool set)
100 {
101 	if (set)
102 		writel(readl(gc->reg_base + offset) | mask,
103 				gc->reg_base + offset);
104 	else
105 		writel(readl(gc->reg_base + offset) & ~mask,
106 				gc->reg_base + offset);
107 }
108 
109 static int liointc_set_type(struct irq_data *data, unsigned int type)
110 {
111 	struct irq_chip_generic *gc = irq_data_get_irq_chip_data(data);
112 	u32 mask = data->mask;
113 	unsigned long flags;
114 
115 	irq_gc_lock_irqsave(gc, flags);
116 	switch (type) {
117 	case IRQ_TYPE_LEVEL_HIGH:
118 		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
119 		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
120 		break;
121 	case IRQ_TYPE_LEVEL_LOW:
122 		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, false);
123 		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
124 		break;
125 	case IRQ_TYPE_EDGE_RISING:
126 		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
127 		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, true);
128 		break;
129 	case IRQ_TYPE_EDGE_FALLING:
130 		liointc_set_bit(gc, LIOINTC_REG_INTC_EDGE, mask, true);
131 		liointc_set_bit(gc, LIOINTC_REG_INTC_POL, mask, false);
132 		break;
133 	default:
134 		irq_gc_unlock_irqrestore(gc, flags);
135 		return -EINVAL;
136 	}
137 	irq_gc_unlock_irqrestore(gc, flags);
138 
139 	irqd_set_trigger_type(data, type);
140 	return 0;
141 }
142 
143 static void liointc_suspend(struct irq_chip_generic *gc)
144 {
145 	struct liointc_priv *priv = gc->private;
146 
147 	priv->int_pol = readl(gc->reg_base + LIOINTC_REG_INTC_POL);
148 	priv->int_edge = readl(gc->reg_base + LIOINTC_REG_INTC_EDGE);
149 }
150 
151 static void liointc_resume(struct irq_chip_generic *gc)
152 {
153 	struct liointc_priv *priv = gc->private;
154 	unsigned long flags;
155 	int i;
156 
157 	irq_gc_lock_irqsave(gc, flags);
158 	/* Disable all at first */
159 	writel(0xffffffff, gc->reg_base + LIOINTC_REG_INTC_DISABLE);
160 	/* Restore map cache */
161 	for (i = 0; i < LIOINTC_CHIP_IRQ; i++)
162 		writeb(priv->map_cache[i], gc->reg_base + i);
163 	writel(priv->int_pol, gc->reg_base + LIOINTC_REG_INTC_POL);
164 	writel(priv->int_edge, gc->reg_base + LIOINTC_REG_INTC_EDGE);
165 	/* Restore mask cache */
166 	writel(gc->mask_cache, gc->reg_base + LIOINTC_REG_INTC_ENABLE);
167 	irq_gc_unlock_irqrestore(gc, flags);
168 }
169 
170 static int parent_irq[LIOINTC_NUM_PARENT];
171 static u32 parent_int_map[LIOINTC_NUM_PARENT];
172 static const char *const parent_names[] = {"int0", "int1", "int2", "int3"};
173 static const char *const core_reg_names[] = {"isr0", "isr1", "isr2", "isr3"};
174 
175 static int liointc_domain_xlate(struct irq_domain *d, struct device_node *ctrlr,
176 			     const u32 *intspec, unsigned int intsize,
177 			     unsigned long *out_hwirq, unsigned int *out_type)
178 {
179 	if (WARN_ON(intsize < 1))
180 		return -EINVAL;
181 	*out_hwirq = intspec[0] - GSI_MIN_CPU_IRQ;
182 
183 	if (intsize > 1)
184 		*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
185 	else
186 		*out_type = IRQ_TYPE_NONE;
187 
188 	return 0;
189 }
190 
191 static const struct irq_domain_ops acpi_irq_gc_ops = {
192 	.map	= irq_map_generic_chip,
193 	.unmap  = irq_unmap_generic_chip,
194 	.xlate	= liointc_domain_xlate,
195 };
196 
197 static int liointc_init(phys_addr_t addr, unsigned long size, int revision,
198 		struct fwnode_handle *domain_handle, struct device_node *node)
199 {
200 	int i, err;
201 	void __iomem *base;
202 	struct irq_chip_type *ct;
203 	struct irq_chip_generic *gc;
204 	struct irq_domain *domain;
205 	struct liointc_priv *priv;
206 
207 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
208 	if (!priv)
209 		return -ENOMEM;
210 
211 	base = ioremap(addr, size);
212 	if (!base)
213 		goto out_free_priv;
214 
215 	for (i = 0; i < LIOINTC_NUM_CORES; i++)
216 		priv->core_isr[i] = base + LIOINTC_REG_INTC_STATUS;
217 
218 	for (i = 0; i < LIOINTC_NUM_PARENT; i++)
219 		priv->handler[i].parent_int_map = parent_int_map[i];
220 
221 	if (revision > 1) {
222 		for (i = 0; i < LIOINTC_NUM_CORES; i++) {
223 			int index = of_property_match_string(node,
224 					"reg-names", core_reg_names[i]);
225 
226 			if (index < 0)
227 				continue;
228 
229 			priv->core_isr[i] = of_iomap(node, index);
230 		}
231 
232 		if (!priv->core_isr[0])
233 			goto out_iounmap;
234 	}
235 
236 	/* Setup IRQ domain */
237 	if (!acpi_disabled)
238 		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
239 					&acpi_irq_gc_ops, priv);
240 	else
241 		domain = irq_domain_create_linear(domain_handle, LIOINTC_CHIP_IRQ,
242 					&irq_generic_chip_ops, priv);
243 	if (!domain) {
244 		pr_err("loongson-liointc: cannot add IRQ domain\n");
245 		goto out_iounmap;
246 	}
247 
248 	err = irq_alloc_domain_generic_chips(domain, LIOINTC_CHIP_IRQ, 1,
249 					(node ? node->full_name : "LIOINTC"),
250 					handle_level_irq, 0, IRQ_NOPROBE, 0);
251 	if (err) {
252 		pr_err("loongson-liointc: unable to register IRQ domain\n");
253 		goto out_free_domain;
254 	}
255 
256 
257 	/* Disable all IRQs */
258 	writel(0xffffffff, base + LIOINTC_REG_INTC_DISABLE);
259 	/* Set to level triggered */
260 	writel(0x0, base + LIOINTC_REG_INTC_EDGE);
261 
262 	/* Generate parent INT part of map cache */
263 	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
264 		u32 pending = priv->handler[i].parent_int_map;
265 
266 		while (pending) {
267 			int bit = __ffs(pending);
268 
269 			priv->map_cache[bit] = BIT(i) << LIOINTC_SHIFT_INTx;
270 			pending &= ~BIT(bit);
271 		}
272 	}
273 
274 	for (i = 0; i < LIOINTC_CHIP_IRQ; i++) {
275 		/* Generate core part of map cache */
276 		priv->map_cache[i] |= BIT(loongson_sysconf.boot_cpu_id);
277 		writeb(priv->map_cache[i], base + i);
278 	}
279 
280 	gc = irq_get_domain_generic_chip(domain, 0);
281 	gc->private = priv;
282 	gc->reg_base = base;
283 	gc->domain = domain;
284 	gc->suspend = liointc_suspend;
285 	gc->resume = liointc_resume;
286 
287 	ct = gc->chip_types;
288 	ct->regs.enable = LIOINTC_REG_INTC_ENABLE;
289 	ct->regs.disable = LIOINTC_REG_INTC_DISABLE;
290 	ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
291 	ct->chip.irq_mask = irq_gc_mask_disable_reg;
292 	ct->chip.irq_mask_ack = irq_gc_mask_disable_reg;
293 	ct->chip.irq_set_type = liointc_set_type;
294 
295 	gc->mask_cache = 0;
296 	priv->gc = gc;
297 
298 	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
299 		if (parent_irq[i] <= 0)
300 			continue;
301 
302 		priv->handler[i].priv = priv;
303 		irq_set_chained_handler_and_data(parent_irq[i],
304 				liointc_chained_handle_irq, &priv->handler[i]);
305 	}
306 
307 	liointc_handle = domain_handle;
308 	return 0;
309 
310 out_free_domain:
311 	irq_domain_remove(domain);
312 out_iounmap:
313 	iounmap(base);
314 out_free_priv:
315 	kfree(priv);
316 
317 	return -EINVAL;
318 }
319 
320 #ifdef CONFIG_OF
321 
322 static int __init liointc_of_init(struct device_node *node,
323 				  struct device_node *parent)
324 {
325 	bool have_parent = FALSE;
326 	int sz, i, index, revision, err = 0;
327 	struct resource res;
328 
329 	if (!of_device_is_compatible(node, "loongson,liointc-2.0")) {
330 		index = 0;
331 		revision = 1;
332 	} else {
333 		index = of_property_match_string(node, "reg-names", "main");
334 		revision = 2;
335 	}
336 
337 	if (of_address_to_resource(node, index, &res))
338 		return -EINVAL;
339 
340 	for (i = 0; i < LIOINTC_NUM_PARENT; i++) {
341 		parent_irq[i] = of_irq_get_byname(node, parent_names[i]);
342 		if (parent_irq[i] > 0)
343 			have_parent = TRUE;
344 	}
345 	if (!have_parent)
346 		return -ENODEV;
347 
348 	sz = of_property_read_variable_u32_array(node,
349 						"loongson,parent_int_map",
350 						&parent_int_map[0],
351 						LIOINTC_NUM_PARENT,
352 						LIOINTC_NUM_PARENT);
353 	if (sz < 4) {
354 		pr_err("loongson-liointc: No parent_int_map\n");
355 		return -ENODEV;
356 	}
357 
358 	err = liointc_init(res.start, resource_size(&res),
359 			revision, of_node_to_fwnode(node), node);
360 	if (err < 0)
361 		return err;
362 
363 	return 0;
364 }
365 
366 IRQCHIP_DECLARE(loongson_liointc_1_0, "loongson,liointc-1.0", liointc_of_init);
367 IRQCHIP_DECLARE(loongson_liointc_1_0a, "loongson,liointc-1.0a", liointc_of_init);
368 IRQCHIP_DECLARE(loongson_liointc_2_0, "loongson,liointc-2.0", liointc_of_init);
369 
370 #endif
371 
372 #ifdef CONFIG_ACPI
373 static int __init htintc_parse_madt(union acpi_subtable_headers *header,
374 					const unsigned long end)
375 {
376 	struct acpi_madt_ht_pic *htintc_entry = (struct acpi_madt_ht_pic *)header;
377 	struct irq_domain *parent = irq_find_matching_fwnode(liointc_handle, DOMAIN_BUS_ANY);
378 
379 	return htvec_acpi_init(parent, htintc_entry);
380 }
381 
382 static int __init acpi_cascade_irqdomain_init(void)
383 {
384 	int r;
385 
386 	r = acpi_table_parse_madt(ACPI_MADT_TYPE_HT_PIC, htintc_parse_madt, 0);
387 	if (r < 0)
388 		return r;
389 
390 	return 0;
391 }
392 
393 int __init liointc_acpi_init(struct irq_domain *parent, struct acpi_madt_lio_pic *acpi_liointc)
394 {
395 	int ret;
396 	struct fwnode_handle *domain_handle;
397 
398 	parent_int_map[0] = acpi_liointc->cascade_map[0];
399 	parent_int_map[1] = acpi_liointc->cascade_map[1];
400 
401 	parent_irq[0] = irq_create_mapping(parent, acpi_liointc->cascade[0]);
402 	parent_irq[1] = irq_create_mapping(parent, acpi_liointc->cascade[1]);
403 
404 	domain_handle = irq_domain_alloc_fwnode(&acpi_liointc->address);
405 	if (!domain_handle) {
406 		pr_err("Unable to allocate domain handle\n");
407 		return -ENOMEM;
408 	}
409 
410 	ret = liointc_init(acpi_liointc->address, acpi_liointc->size,
411 			   1, domain_handle, NULL);
412 	if (ret == 0)
413 		ret = acpi_cascade_irqdomain_init();
414 	else
415 		irq_domain_free_fwnode(domain_handle);
416 
417 	return ret;
418 }
419 #endif
420