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

source code of linux/drivers/irqchip/irq-loongson-pch-pic.c