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
61 static int exin_avail;
62 static u32 ltq_eiu_irq[MAX_EIU];
63 static void __iomem *ltq_icu_membase[NR_CPUS];
64 static void __iomem *ltq_eiu_membase;
65 static struct irq_domain *ltq_domain;
66 static DEFINE_SPINLOCK(ltq_eiu_lock);
67 static DEFINE_RAW_SPINLOCK(ltq_icu_lock);
68 static int ltq_perfcount_irq;
69
ltq_eiu_get_irq(int exin)70 int ltq_eiu_get_irq(int exin)
71 {
72 if (exin < exin_avail)
73 return ltq_eiu_irq[exin];
74 return -1;
75 }
76
ltq_disable_irq(struct irq_data * d)77 void 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(<q_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(<q_icu_lock, flags);
93 }
94
ltq_mask_and_ack_irq(struct irq_data * d)95 void 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(<q_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(<q_icu_lock, flags);
112 }
113
ltq_ack_irq(struct irq_data * d)114 static 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(<q_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(<q_icu_lock, flags);
128 }
129
ltq_enable_irq(struct irq_data * d)130 void 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(<q_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(<q_icu_lock, flags);
151 }
152
ltq_eiu_settype(struct irq_data * d,unsigned int type)153 static 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(<q_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(<q_eiu_lock, flags);
198 }
199 }
200
201 return 0;
202 }
203
ltq_startup_eiu_irq(struct irq_data * d)204 static 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
ltq_shutdown_eiu_irq(struct irq_data * d)226 static 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)
ltq_icu_irq_set_affinity(struct irq_data * d,const struct cpumask * cpumask,bool force)242 static 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
256 static 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
269 static 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
ltq_hw_irq_handler(struct irq_desc * desc)285 static 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 == 0) && LTQ_EBU_PCC_ISTAT)
306 ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_ISTAT) | 0x10,
307 LTQ_EBU_PCC_ISTAT);
308 }
309
icu_map(struct irq_domain * d,unsigned int irq,irq_hw_number_t hw)310 static int icu_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
311 {
312 struct irq_chip *chip = <q_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 = <q_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
332 static const struct irq_domain_ops irq_domain_ops = {
333 .xlate = irq_domain_xlate_onetwocell,
334 .map = icu_map,
335 };
336
icu_of_init(struct device_node * node,struct device_node * parent)337 int __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
get_c0_perfcount_int(void)414 int get_c0_perfcount_int(void)
415 {
416 return ltq_perfcount_irq;
417 }
418 EXPORT_SYMBOL_GPL(get_c0_perfcount_int);
419
get_c0_compare_int(void)420 unsigned int get_c0_compare_int(void)
421 {
422 return CP0_LEGACY_COMPARE_IRQ;
423 }
424
425 static const struct of_device_id of_irq_ids[] __initconst = {
426 { .compatible = "lantiq,icu", .data = icu_of_init },
427 {},
428 };
429
arch_init_irq(void)430 void __init arch_init_irq(void)
431 {
432 of_irq_init(of_irq_ids);
433 }
434
