1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020, Jiaxun Yang <jiaxun.yang@flygoat.com>
4 * Loongson PCH PIC support
5 */
6
7 #define pr_fmt(fmt) "pch-pic: " fmt
8
9 #include <linux/interrupt.h>
10 #include <linux/irq.h>
11 #include <linux/irqchip.h>
12 #include <linux/irqdomain.h>
13 #include <linux/kernel.h>
14 #include <linux/platform_device.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_irq.h>
18 #include <linux/syscore_ops.h>
19
20 #include "irq-loongson.h"
21
22 /* Registers */
23 #define PCH_PIC_MASK 0x20
24 #define PCH_PIC_HTMSI_EN 0x40
25 #define PCH_PIC_EDGE 0x60
26 #define PCH_PIC_CLR 0x80
27 #define PCH_PIC_AUTO0 0xc0
28 #define PCH_PIC_AUTO1 0xe0
29 #define PCH_INT_ROUTE(irq) (0x100 + irq)
30 #define PCH_INT_HTVEC(irq) (0x200 + irq)
31 #define PCH_PIC_POL 0x3e0
32
33 #define PIC_COUNT_PER_REG 32
34 #define PIC_REG_COUNT 2
35 #define PIC_COUNT (PIC_COUNT_PER_REG * PIC_REG_COUNT)
36 #define PIC_REG_IDX(irq_id) ((irq_id) / PIC_COUNT_PER_REG)
37 #define PIC_REG_BIT(irq_id) ((irq_id) % PIC_COUNT_PER_REG)
38 #define PIC_UNDEF_VECTOR 255
39
40 static int nr_pics;
41
42 struct pch_pic {
43 void __iomem *base;
44 struct irq_domain *pic_domain;
45 u32 ht_vec_base;
46 raw_spinlock_t pic_lock;
47 u32 vec_count;
48 u32 gsi_base;
49 u32 saved_vec_en[PIC_REG_COUNT];
50 u32 saved_vec_pol[PIC_REG_COUNT];
51 u32 saved_vec_edge[PIC_REG_COUNT];
52 u8 table[PIC_COUNT];
53 int inuse;
54 };
55
56 static struct pch_pic *pch_pic_priv[MAX_IO_PICS];
57
58 struct fwnode_handle *pch_pic_handle[MAX_IO_PICS];
59
hwirq_to_bit(struct pch_pic * priv,int hirq)60 static inline u8 hwirq_to_bit(struct pch_pic *priv, int hirq)
61 {
62 return priv->table[hirq];
63 }
64
pch_pic_bitset(struct pch_pic * priv,int offset,int bit)65 static void pch_pic_bitset(struct pch_pic *priv, int offset, int bit)
66 {
67 u32 reg;
68 void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
69
70 raw_spin_lock(&priv->pic_lock);
71 reg = readl(addr);
72 reg |= BIT(PIC_REG_BIT(bit));
73 writel(reg, addr);
74 raw_spin_unlock(&priv->pic_lock);
75 }
76
pch_pic_bitclr(struct pch_pic * priv,int offset,int bit)77 static void pch_pic_bitclr(struct pch_pic *priv, int offset, int bit)
78 {
79 u32 reg;
80 void __iomem *addr = priv->base + offset + PIC_REG_IDX(bit) * 4;
81
82 raw_spin_lock(&priv->pic_lock);
83 reg = readl(addr);
84 reg &= ~BIT(PIC_REG_BIT(bit));
85 writel(reg, addr);
86 raw_spin_unlock(&priv->pic_lock);
87 }
88
pch_pic_mask_irq(struct irq_data * d)89 static void pch_pic_mask_irq(struct irq_data *d)
90 {
91 struct pch_pic *priv = irq_data_get_irq_chip_data(d);
92
93 pch_pic_bitset(priv, PCH_PIC_MASK, hwirq_to_bit(priv, d->hwirq));
94 irq_chip_mask_parent(d);
95 }
96
pch_pic_unmask_irq(struct irq_data * d)97 static void pch_pic_unmask_irq(struct irq_data *d)
98 {
99 struct pch_pic *priv = irq_data_get_irq_chip_data(d);
100 int bit = hwirq_to_bit(priv, d->hwirq);
101
102 writel(BIT(PIC_REG_BIT(bit)),
103 priv->base + PCH_PIC_CLR + PIC_REG_IDX(bit) * 4);
104
105 irq_chip_unmask_parent(d);
106 pch_pic_bitclr(priv, PCH_PIC_MASK, bit);
107 }
108
pch_pic_set_type(struct irq_data * d,unsigned int type)109 static int pch_pic_set_type(struct irq_data *d, unsigned int type)
110 {
111 struct pch_pic *priv = irq_data_get_irq_chip_data(d);
112 int bit = hwirq_to_bit(priv, d->hwirq);
113 int ret = 0;
114
115 switch (type) {
116 case IRQ_TYPE_EDGE_RISING:
117 pch_pic_bitset(priv, PCH_PIC_EDGE, bit);
118 pch_pic_bitclr(priv, PCH_PIC_POL, bit);
119 irq_set_handler_locked(d, handle_edge_irq);
120 break;
121 case IRQ_TYPE_EDGE_FALLING:
122 pch_pic_bitset(priv, PCH_PIC_EDGE, bit);
123 pch_pic_bitset(priv, PCH_PIC_POL, bit);
124 irq_set_handler_locked(d, handle_edge_irq);
125 break;
126 case IRQ_TYPE_LEVEL_HIGH:
127 pch_pic_bitclr(priv, PCH_PIC_EDGE, bit);
128 pch_pic_bitclr(priv, PCH_PIC_POL, bit);
129 irq_set_handler_locked(d, handle_level_irq);
130 break;
131 case IRQ_TYPE_LEVEL_LOW:
132 pch_pic_bitclr(priv, PCH_PIC_EDGE, bit);
133 pch_pic_bitset(priv, PCH_PIC_POL, bit);
134 irq_set_handler_locked(d, handle_level_irq);
135 break;
136 default:
137 ret = -EINVAL;
138 break;
139 }
140
141 return ret;
142 }
143
pch_pic_ack_irq(struct irq_data * d)144 static void pch_pic_ack_irq(struct irq_data *d)
145 {
146 unsigned int reg;
147 struct pch_pic *priv = irq_data_get_irq_chip_data(d);
148 int bit = hwirq_to_bit(priv, d->hwirq);
149
150 reg = readl(priv->base + PCH_PIC_EDGE + PIC_REG_IDX(bit) * 4);
151 if (reg & BIT(PIC_REG_BIT(bit))) {
152 writel(BIT(PIC_REG_BIT(bit)),
153 priv->base + PCH_PIC_CLR + PIC_REG_IDX(bit) * 4);
154 }
155 irq_chip_ack_parent(d);
156 }
157
158 static struct irq_chip pch_pic_irq_chip = {
159 .name = "PCH PIC",
160 .irq_mask = pch_pic_mask_irq,
161 .irq_unmask = pch_pic_unmask_irq,
162 .irq_ack = pch_pic_ack_irq,
163 .irq_set_affinity = irq_chip_set_affinity_parent,
164 .irq_set_type = pch_pic_set_type,
165 .flags = IRQCHIP_SKIP_SET_WAKE,
166 };
167
pch_pic_domain_translate(struct irq_domain * d,struct irq_fwspec * fwspec,unsigned long * hwirq,unsigned int * type)168 static int pch_pic_domain_translate(struct irq_domain *d,
169 struct irq_fwspec *fwspec,
170 unsigned long *hwirq,
171 unsigned int *type)
172 {
173 struct pch_pic *priv = d->host_data;
174 struct device_node *of_node = to_of_node(fwspec->fwnode);
175 unsigned long flags;
176 int i;
177
178 if (of_node) {
179 if (fwspec->param_count < 2)
180 return -EINVAL;
181
182 *hwirq = fwspec->param[0];
183 *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
184 } else {
185 if (fwspec->param_count < 1)
186 return -EINVAL;
187
188 *hwirq = fwspec->param[0] - priv->gsi_base;
189
190 if (fwspec->param_count > 1)
191 *type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
192 else
193 *type = IRQ_TYPE_NONE;
194 }
195
196 raw_spin_lock_irqsave(&priv->pic_lock, flags);
197 /* Check pic-table to confirm if the hwirq has been assigned */
198 for (i = 0; i < priv->inuse; i++) {
199 if (priv->table[i] == *hwirq) {
200 *hwirq = i;
201 break;
202 }
203 }
204 if (i == priv->inuse) {
205 /* Assign a new hwirq in pic-table */
206 if (priv->inuse >= PIC_COUNT) {
207 pr_err("pch-pic domain has no free vectors\n");
208 raw_spin_unlock_irqrestore(&priv->pic_lock, flags);
209 return -EINVAL;
210 }
211 priv->table[priv->inuse] = *hwirq;
212 *hwirq = priv->inuse++;
213 }
214 raw_spin_unlock_irqrestore(&priv->pic_lock, flags);
215
216 return 0;
217 }
218
pch_pic_alloc(struct irq_domain * domain,unsigned int virq,unsigned int nr_irqs,void * arg)219 static int pch_pic_alloc(struct irq_domain *domain, unsigned int virq,
220 unsigned int nr_irqs, void *arg)
221 {
222 int err;
223 unsigned int type;
224 unsigned long hwirq;
225 struct irq_fwspec *fwspec = arg;
226 struct irq_fwspec parent_fwspec;
227 struct pch_pic *priv = domain->host_data;
228
229 err = pch_pic_domain_translate(domain, fwspec, &hwirq, &type);
230 if (err)
231 return err;
232
233 /* Write vector ID */
234 writeb(priv->ht_vec_base + hwirq, priv->base + PCH_INT_HTVEC(hwirq_to_bit(priv, hwirq)));
235
236 parent_fwspec.fwnode = domain->parent->fwnode;
237 parent_fwspec.param_count = 1;
238 parent_fwspec.param[0] = hwirq + priv->ht_vec_base;
239
240 err = irq_domain_alloc_irqs_parent(domain, virq, 1, &parent_fwspec);
241 if (err)
242 return err;
243
244 irq_domain_set_info(domain, virq, hwirq,
245 &pch_pic_irq_chip, priv,
246 handle_level_irq, NULL, NULL);
247 irq_set_probe(virq);
248
249 return 0;
250 }
251
252 static const struct irq_domain_ops pch_pic_domain_ops = {
253 .translate = pch_pic_domain_translate,
254 .alloc = pch_pic_alloc,
255 .free = irq_domain_free_irqs_parent,
256 };
257
pch_pic_reset(struct pch_pic * priv)258 static void pch_pic_reset(struct pch_pic *priv)
259 {
260 int i;
261
262 for (i = 0; i < PIC_COUNT; i++) {
263 /* Write vector ID */
264 writeb(priv->ht_vec_base + i, priv->base + PCH_INT_HTVEC(hwirq_to_bit(priv, i)));
265 /* Hardcode route to HT0 Lo */
266 writeb(1, priv->base + PCH_INT_ROUTE(i));
267 }
268
269 for (i = 0; i < PIC_REG_COUNT; i++) {
270 /* Clear IRQ cause registers, mask all interrupts */
271 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_MASK + 4 * i);
272 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_CLR + 4 * i);
273 /* Clear auto bounce, we don't need that */
274 writel_relaxed(0, priv->base + PCH_PIC_AUTO0 + 4 * i);
275 writel_relaxed(0, priv->base + PCH_PIC_AUTO1 + 4 * i);
276 /* Enable HTMSI transformer */
277 writel_relaxed(0xFFFFFFFF, priv->base + PCH_PIC_HTMSI_EN + 4 * i);
278 }
279 }
280
pch_pic_suspend(void * data)281 static int pch_pic_suspend(void *data)
282 {
283 int i, j;
284
285 for (i = 0; i < nr_pics; i++) {
286 for (j = 0; j < PIC_REG_COUNT; j++) {
287 pch_pic_priv[i]->saved_vec_pol[j] =
288 readl(pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
289 pch_pic_priv[i]->saved_vec_edge[j] =
290 readl(pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
291 pch_pic_priv[i]->saved_vec_en[j] =
292 readl(pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
293 }
294 }
295
296 return 0;
297 }
298
pch_pic_resume(void * data)299 static void pch_pic_resume(void *data)
300 {
301 int i, j;
302
303 for (i = 0; i < nr_pics; i++) {
304 pch_pic_reset(pch_pic_priv[i]);
305 for (j = 0; j < PIC_REG_COUNT; j++) {
306 writel(pch_pic_priv[i]->saved_vec_pol[j],
307 pch_pic_priv[i]->base + PCH_PIC_POL + 4 * j);
308 writel(pch_pic_priv[i]->saved_vec_edge[j],
309 pch_pic_priv[i]->base + PCH_PIC_EDGE + 4 * j);
310 writel(pch_pic_priv[i]->saved_vec_en[j],
311 pch_pic_priv[i]->base + PCH_PIC_MASK + 4 * j);
312 }
313 }
314 }
315
316 static const struct syscore_ops pch_pic_syscore_ops = {
317 .suspend = pch_pic_suspend,
318 .resume = pch_pic_resume,
319 };
320
321 static struct syscore pch_pic_syscore = {
322 .ops = &pch_pic_syscore_ops,
323 };
324
pch_pic_init(phys_addr_t addr,unsigned long size,int vec_base,struct irq_domain * parent_domain,struct fwnode_handle * domain_handle,u32 gsi_base)325 static int pch_pic_init(phys_addr_t addr, unsigned long size, int vec_base,
326 struct irq_domain *parent_domain, struct fwnode_handle *domain_handle,
327 u32 gsi_base)
328 {
329 struct pch_pic *priv;
330 int i;
331
332 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
333 if (!priv)
334 return -ENOMEM;
335
336 raw_spin_lock_init(&priv->pic_lock);
337 priv->base = ioremap(addr, size);
338 if (!priv->base)
339 goto free_priv;
340
341 priv->inuse = 0;
342 for (i = 0; i < PIC_COUNT; i++)
343 priv->table[i] = PIC_UNDEF_VECTOR;
344
345 priv->ht_vec_base = vec_base;
346 priv->vec_count = ((readq(priv->base) >> 48) & 0xff) + 1;
347 priv->gsi_base = gsi_base;
348
349 priv->pic_domain = irq_domain_create_hierarchy(parent_domain, 0,
350 priv->vec_count, domain_handle,
351 &pch_pic_domain_ops, priv);
352
353 if (!priv->pic_domain) {
354 pr_err("Failed to create IRQ domain\n");
355 goto iounmap_base;
356 }
357
358 pch_pic_reset(priv);
359 pch_pic_handle[nr_pics] = domain_handle;
360 pch_pic_priv[nr_pics++] = priv;
361
362 if (nr_pics == 1)
363 register_syscore(&pch_pic_syscore);
364
365 return 0;
366
367 iounmap_base:
368 iounmap(priv->base);
369 free_priv:
370 kfree(priv);
371
372 return -EINVAL;
373 }
374
375 #ifdef CONFIG_OF
376
pch_pic_of_init(struct device_node * node,struct device_node * parent)377 static int pch_pic_of_init(struct device_node *node,
378 struct device_node *parent)
379 {
380 int err, vec_base;
381 struct resource res;
382 struct irq_domain *parent_domain;
383
384 if (of_address_to_resource(node, 0, &res))
385 return -EINVAL;
386
387 parent_domain = irq_find_host(parent);
388 if (!parent_domain) {
389 pr_err("Failed to find the parent domain\n");
390 return -ENXIO;
391 }
392
393 if (of_property_read_u32(node, "loongson,pic-base-vec", &vec_base)) {
394 pr_err("Failed to determine pic-base-vec\n");
395 return -EINVAL;
396 }
397
398 err = pch_pic_init(res.start, resource_size(&res), vec_base,
399 parent_domain, of_fwnode_handle(node), 0);
400 if (err < 0)
401 return err;
402
403 return 0;
404 }
405
406 IRQCHIP_DECLARE(pch_pic, "loongson,pch-pic-1.0", pch_pic_of_init);
407
408 #endif
409
410 #ifdef CONFIG_ACPI
find_pch_pic(u32 gsi)411 int find_pch_pic(u32 gsi)
412 {
413 int i;
414
415 /* Find the PCH_PIC that manages this GSI. */
416 for (i = 0; i < MAX_IO_PICS; i++) {
417 struct pch_pic *priv = pch_pic_priv[i];
418
419 if (!priv)
420 return -1;
421
422 if (gsi >= priv->gsi_base && gsi < (priv->gsi_base + priv->vec_count))
423 return i;
424 }
425
426 pr_err("ERROR: Unable to locate PCH_PIC for GSI %d\n", gsi);
427 return -1;
428 }
429
pch_lpc_parse_madt(union acpi_subtable_headers * header,const unsigned long end)430 static int __init pch_lpc_parse_madt(union acpi_subtable_headers *header,
431 const unsigned long end)
432 {
433 struct acpi_madt_lpc_pic *pchlpc_entry = (struct acpi_madt_lpc_pic *)header;
434
435 return pch_lpc_acpi_init(pch_pic_priv[0]->pic_domain, pchlpc_entry);
436 }
437
acpi_cascade_irqdomain_init(void)438 static int __init acpi_cascade_irqdomain_init(void)
439 {
440 int r;
441
442 r = acpi_table_parse_madt(ACPI_MADT_TYPE_LPC_PIC, pch_lpc_parse_madt, 0);
443 if (r < 0)
444 return r;
445
446 return 0;
447 }
448
pch_pic_acpi_init(struct irq_domain * parent,struct acpi_madt_bio_pic * acpi_pchpic)449 int __init pch_pic_acpi_init(struct irq_domain *parent,
450 struct acpi_madt_bio_pic *acpi_pchpic)
451 {
452 int ret;
453 struct fwnode_handle *domain_handle;
454
455 if (find_pch_pic(acpi_pchpic->gsi_base) >= 0)
456 return 0;
457
458 domain_handle = irq_domain_alloc_fwnode(&acpi_pchpic->address);
459 if (!domain_handle) {
460 pr_err("Unable to allocate domain handle\n");
461 return -ENOMEM;
462 }
463
464 ret = pch_pic_init(acpi_pchpic->address, acpi_pchpic->size,
465 0, parent, domain_handle, acpi_pchpic->gsi_base);
466
467 if (ret < 0) {
468 irq_domain_free_fwnode(domain_handle);
469 return ret;
470 }
471
472 if (acpi_pchpic->id == 0)
473 ret = acpi_cascade_irqdomain_init();
474
475 return ret;
476 }
477 #endif
478