xref: /kernel/linux/linux-5.10/arch/mips/lantiq/irq.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *
4 * Copyright (C) 2010 John Crispin <john@phrozen.org>
5 * Copyright (C) 2010 Thomas Langer <thomas.langer@lantiq.com>
6 */
7
8#include <linux/interrupt.h>
9#include <linux/ioport.h>
10#include <linux/sched.h>
11#include <linux/irqdomain.h>
12#include <linux/of_platform.h>
13#include <linux/of_address.h>
14#include <linux/of_irq.h>
15
16#include <asm/bootinfo.h>
17#include <asm/irq_cpu.h>
18
19#include <lantiq_soc.h>
20#include <irq.h>
21
22/* register definitions - internal irqs */
23#define LTQ_ICU_ISR		0x0000
24#define LTQ_ICU_IER		0x0008
25#define LTQ_ICU_IOSR		0x0010
26#define LTQ_ICU_IRSR		0x0018
27#define LTQ_ICU_IMR		0x0020
28
29#define LTQ_ICU_IM_SIZE		0x28
30
31/* register definitions - external irqs */
32#define LTQ_EIU_EXIN_C		0x0000
33#define LTQ_EIU_EXIN_INIC	0x0004
34#define LTQ_EIU_EXIN_INC	0x0008
35#define LTQ_EIU_EXIN_INEN	0x000C
36
37/* number of external interrupts */
38#define MAX_EIU			6
39
40/* the performance counter */
41#define LTQ_PERF_IRQ		(INT_NUM_IM4_IRL0 + 31)
42
43/*
44 * irqs generated by devices attached to the EBU need to be acked in
45 * a special manner
46 */
47#define LTQ_ICU_EBU_IRQ		22
48
49#define ltq_icu_w32(vpe, m, x, y)	\
50	ltq_w32((x), ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (y))
51
52#define ltq_icu_r32(vpe, m, x)		\
53	ltq_r32(ltq_icu_membase[vpe] + m*LTQ_ICU_IM_SIZE + (x))
54
55#define ltq_eiu_w32(x, y)	ltq_w32((x), ltq_eiu_membase + (y))
56#define ltq_eiu_r32(x)		ltq_r32(ltq_eiu_membase + (x))
57
58/* we have a cascade of 8 irqs */
59#define MIPS_CPU_IRQ_CASCADE		8
60
61static int exin_avail;
62static u32 ltq_eiu_irq[MAX_EIU];
63static void __iomem *ltq_icu_membase[NR_CPUS];
64static void __iomem *ltq_eiu_membase;
65static struct irq_domain *ltq_domain;
66static DEFINE_SPINLOCK(ltq_eiu_lock);
67static DEFINE_RAW_SPINLOCK(ltq_icu_lock);
68static int ltq_perfcount_irq;
69
70int ltq_eiu_get_irq(int exin)
71{
72	if (exin < exin_avail)
73		return ltq_eiu_irq[exin];
74	return -1;
75}
76
77void ltq_disable_irq(struct irq_data *d)
78{
79	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
80	unsigned long im = offset / INT_NUM_IM_OFFSET;
81	unsigned long flags;
82	int vpe;
83
84	offset %= INT_NUM_IM_OFFSET;
85
86	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
87	for_each_present_cpu(vpe) {
88		ltq_icu_w32(vpe, im,
89			    ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
90			    LTQ_ICU_IER);
91	}
92	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
93}
94
95void ltq_mask_and_ack_irq(struct irq_data *d)
96{
97	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
98	unsigned long im = offset / INT_NUM_IM_OFFSET;
99	unsigned long flags;
100	int vpe;
101
102	offset %= INT_NUM_IM_OFFSET;
103
104	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
105	for_each_present_cpu(vpe) {
106		ltq_icu_w32(vpe, im,
107			    ltq_icu_r32(vpe, im, LTQ_ICU_IER) & ~BIT(offset),
108			    LTQ_ICU_IER);
109		ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
110	}
111	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
112}
113
114static void ltq_ack_irq(struct irq_data *d)
115{
116	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
117	unsigned long im = offset / INT_NUM_IM_OFFSET;
118	unsigned long flags;
119	int vpe;
120
121	offset %= INT_NUM_IM_OFFSET;
122
123	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
124	for_each_present_cpu(vpe) {
125		ltq_icu_w32(vpe, im, BIT(offset), LTQ_ICU_ISR);
126	}
127	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
128}
129
130void ltq_enable_irq(struct irq_data *d)
131{
132	unsigned long offset = d->hwirq - MIPS_CPU_IRQ_CASCADE;
133	unsigned long im = offset / INT_NUM_IM_OFFSET;
134	unsigned long flags;
135	int vpe;
136
137	offset %= INT_NUM_IM_OFFSET;
138
139	vpe = cpumask_first(irq_data_get_effective_affinity_mask(d));
140
141	/* This shouldn't be even possible, maybe during CPU hotplug spam */
142	if (unlikely(vpe >= nr_cpu_ids))
143		vpe = smp_processor_id();
144
145	raw_spin_lock_irqsave(&ltq_icu_lock, flags);
146
147	ltq_icu_w32(vpe, im, ltq_icu_r32(vpe, im, LTQ_ICU_IER) | BIT(offset),
148		    LTQ_ICU_IER);
149
150	raw_spin_unlock_irqrestore(&ltq_icu_lock, flags);
151}
152
153static int ltq_eiu_settype(struct irq_data *d, unsigned int type)
154{
155	int i;
156	unsigned long flags;
157
158	for (i = 0; i < exin_avail; i++) {
159		if (d->hwirq == ltq_eiu_irq[i]) {
160			int val = 0;
161			int edge = 0;
162
163			switch (type) {
164			case IRQF_TRIGGER_NONE:
165				break;
166			case IRQF_TRIGGER_RISING:
167				val = 1;
168				edge = 1;
169				break;
170			case IRQF_TRIGGER_FALLING:
171				val = 2;
172				edge = 1;
173				break;
174			case IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING:
175				val = 3;
176				edge = 1;
177				break;
178			case IRQF_TRIGGER_HIGH:
179				val = 5;
180				break;
181			case IRQF_TRIGGER_LOW:
182				val = 6;
183				break;
184			default:
185				pr_err("invalid type %d for irq %ld\n",
186					type, d->hwirq);
187				return -EINVAL;
188			}
189
190			if (edge)
191				irq_set_handler(d->hwirq, handle_edge_irq);
192
193			spin_lock_irqsave(&ltq_eiu_lock, flags);
194			ltq_eiu_w32((ltq_eiu_r32(LTQ_EIU_EXIN_C) &
195				    (~(7 << (i * 4)))) | (val << (i * 4)),
196				    LTQ_EIU_EXIN_C);
197			spin_unlock_irqrestore(&ltq_eiu_lock, flags);
198		}
199	}
200
201	return 0;
202}
203
204static unsigned int ltq_startup_eiu_irq(struct irq_data *d)
205{
206	int i;
207
208	ltq_enable_irq(d);
209	for (i = 0; i < exin_avail; i++) {
210		if (d->hwirq == ltq_eiu_irq[i]) {
211			/* by default we are low level triggered */
212			ltq_eiu_settype(d, IRQF_TRIGGER_LOW);
213			/* clear all pending */
214			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INC) & ~BIT(i),
215				LTQ_EIU_EXIN_INC);
216			/* enable */
217			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) | BIT(i),
218				LTQ_EIU_EXIN_INEN);
219			break;
220		}
221	}
222
223	return 0;
224}
225
226static void ltq_shutdown_eiu_irq(struct irq_data *d)
227{
228	int i;
229
230	ltq_disable_irq(d);
231	for (i = 0; i < exin_avail; i++) {
232		if (d->hwirq == ltq_eiu_irq[i]) {
233			/* disable */
234			ltq_eiu_w32(ltq_eiu_r32(LTQ_EIU_EXIN_INEN) & ~BIT(i),
235				LTQ_EIU_EXIN_INEN);
236			break;
237		}
238	}
239}
240
241#if defined(CONFIG_SMP)
242static int ltq_icu_irq_set_affinity(struct irq_data *d,
243				    const struct cpumask *cpumask, bool force)
244{
245	struct cpumask tmask;
246
247	if (!cpumask_and(&tmask, cpumask, cpu_online_mask))
248		return -EINVAL;
249
250	irq_data_update_effective_affinity(d, &tmask);
251
252	return IRQ_SET_MASK_OK;
253}
254#endif
255
256static struct irq_chip ltq_irq_type = {
257	.name = "icu",
258	.irq_enable = ltq_enable_irq,
259	.irq_disable = ltq_disable_irq,
260	.irq_unmask = ltq_enable_irq,
261	.irq_ack = ltq_ack_irq,
262	.irq_mask = ltq_disable_irq,
263	.irq_mask_ack = ltq_mask_and_ack_irq,
264#if defined(CONFIG_SMP)
265	.irq_set_affinity = ltq_icu_irq_set_affinity,
266#endif
267};
268
269static struct irq_chip ltq_eiu_type = {
270	.name = "eiu",
271	.irq_startup = ltq_startup_eiu_irq,
272	.irq_shutdown = ltq_shutdown_eiu_irq,
273	.irq_enable = ltq_enable_irq,
274	.irq_disable = ltq_disable_irq,
275	.irq_unmask = ltq_enable_irq,
276	.irq_ack = ltq_ack_irq,
277	.irq_mask = ltq_disable_irq,
278	.irq_mask_ack = ltq_mask_and_ack_irq,
279	.irq_set_type = ltq_eiu_settype,
280#if defined(CONFIG_SMP)
281	.irq_set_affinity = ltq_icu_irq_set_affinity,
282#endif
283};
284
285static void ltq_hw_irq_handler(struct irq_desc *desc)
286{
287	unsigned int module = irq_desc_get_irq(desc) - 2;
288	u32 irq;
289	irq_hw_number_t hwirq;
290	int vpe = smp_processor_id();
291
292	irq = ltq_icu_r32(vpe, module, LTQ_ICU_IOSR);
293	if (irq == 0)
294		return;
295
296	/*
297	 * silicon bug causes only the msb set to 1 to be valid. all
298	 * other bits might be bogus
299	 */
300	irq = __fls(irq);
301	hwirq = irq + MIPS_CPU_IRQ_CASCADE + (INT_NUM_IM_OFFSET * module);
302	generic_handle_irq(irq_linear_revmap(ltq_domain, hwirq));
303
304	/* if this is a EBU irq, we need to ack it or get a deadlock */
305	if (irq == LTQ_ICU_EBU_IRQ && !module && LTQ_EBU_PCC_ISTAT != 0)
306		ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
307			LTQ_EBU_PCC_ISTAT);
308}
309
310static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
311{
312	struct irq_chip *chip = &ltq_irq_type;
313	struct irq_data *data;
314	int i;
315
316	if (hw < MIPS_CPU_IRQ_CASCADE)
317		return 0;
318
319	for (i = 0; i < exin_avail; i++)
320		if (hw == ltq_eiu_irq[i])
321			chip = &ltq_eiu_type;
322
323	data = irq_get_irq_data(irq);
324
325	irq_data_update_effective_affinity(data, cpumask_of(0));
326
327	irq_set_chip_and_handler(irq, chip, handle_level_irq);
328
329	return 0;
330}
331
332static const struct irq_domain_ops irq_domain_ops = {
333	.xlate = irq_domain_xlate_onetwocell,
334	.map = icu_map,
335};
336
337int __init icu_of_init(struct device_node *node, struct device_node *parent)
338{
339	struct device_node *eiu_node;
340	struct resource res;
341	int i, ret, vpe;
342
343	/* load register regions of available ICUs */
344	for_each_possible_cpu(vpe) {
345		if (of_address_to_resource(node, vpe, &res))
346			panic("Failed to get icu%i memory range", vpe);
347
348		if (!request_mem_region(res.start, resource_size(&res),
349					res.name))
350			pr_err("Failed to request icu%i memory\n", vpe);
351
352		ltq_icu_membase[vpe] = ioremap(res.start,
353					resource_size(&res));
354
355		if (!ltq_icu_membase[vpe])
356			panic("Failed to remap icu%i memory", vpe);
357	}
358
359	/* turn off all irqs by default */
360	for_each_possible_cpu(vpe) {
361		for (i = 0; i < MAX_IM; i++) {
362			/* make sure all irqs are turned off by default */
363			ltq_icu_w32(vpe, i, 0, LTQ_ICU_IER);
364
365			/* clear all possibly pending interrupts */
366			ltq_icu_w32(vpe, i, ~0, LTQ_ICU_ISR);
367			ltq_icu_w32(vpe, i, ~0, LTQ_ICU_IMR);
368
369			/* clear resend */
370			ltq_icu_w32(vpe, i, 0, LTQ_ICU_IRSR);
371		}
372	}
373
374	mips_cpu_irq_init();
375
376	for (i = 0; i < MAX_IM; i++)
377		irq_set_chained_handler(i + 2, ltq_hw_irq_handler);
378
379	ltq_domain = irq_domain_add_linear(node,
380		(MAX_IM * INT_NUM_IM_OFFSET) + MIPS_CPU_IRQ_CASCADE,
381		&irq_domain_ops, 0);
382
383	/* tell oprofile which irq to use */
384	ltq_perfcount_irq = irq_create_mapping(ltq_domain, LTQ_PERF_IRQ);
385
386	/* the external interrupts are optional and xway only */
387	eiu_node = of_find_compatible_node(NULL, NULL, "lantiq,eiu-xway");
388	if (eiu_node && !of_address_to_resource(eiu_node, 0, &res)) {
389		/* find out how many external irq sources we have */
390		exin_avail = of_property_count_u32_elems(eiu_node,
391							 "lantiq,eiu-irqs");
392
393		if (exin_avail > MAX_EIU)
394			exin_avail = MAX_EIU;
395
396		ret = of_property_read_u32_array(eiu_node, "lantiq,eiu-irqs",
397						ltq_eiu_irq, exin_avail);
398		if (ret)
399			panic("failed to load external irq resources");
400
401		if (!request_mem_region(res.start, resource_size(&res),
402							res.name))
403			pr_err("Failed to request eiu memory");
404
405		ltq_eiu_membase = ioremap(res.start,
406							resource_size(&res));
407		if (!ltq_eiu_membase)
408			panic("Failed to remap eiu memory");
409	}
410
411	return 0;
412}
413
414int get_c0_perfcount_int(void)
415{
416	return ltq_perfcount_irq;
417}
418EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
419
420unsigned int get_c0_compare_int(void)
421{
422	return CP0_LEGACY_COMPARE_IRQ;
423}
424
425static const struct of_device_id of_irq_ids[] __initconst = {
426	{ .compatible = "lantiq,icu", .data = icu_of_init },
427	{},
428};
429
430void __init arch_init_irq(void)
431{
432	of_irq_init(of_irq_ids);
433}
434