1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
|
/*
* drivers/irqchip/irq-crossbar.c
*
* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
* Author: Sricharan R <r.sricharan@ti.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irqchip.h>
#include <linux/irqdomain.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/slab.h>
#define IRQ_FREE -1
#define IRQ_RESERVED -2
#define IRQ_SKIP -3
#define GIC_IRQ_START 32
/**
* struct crossbar_device - crossbar device description
* @lock: spinlock serializing access to @irq_map
* @int_max: maximum number of supported interrupts
* @safe_map: safe default value to initialize the crossbar
* @max_crossbar_sources: Maximum number of crossbar sources
* @irq_map: array of interrupts to crossbar number mapping
* @crossbar_base: crossbar base address
* @register_offsets: offsets for each irq number
* @write: register write function pointer
*/
struct crossbar_device {
raw_spinlock_t lock;
uint int_max;
uint safe_map;
uint max_crossbar_sources;
uint *irq_map;
void __iomem *crossbar_base;
int *register_offsets;
void (*write)(int, int);
};
static struct crossbar_device *cb;
static void crossbar_writel(int irq_no, int cb_no)
{
writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
}
static void crossbar_writew(int irq_no, int cb_no)
{
writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
}
static void crossbar_writeb(int irq_no, int cb_no)
{
writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
}
static struct irq_chip crossbar_chip = {
.name = "CBAR",
.irq_eoi = irq_chip_eoi_parent,
.irq_mask = irq_chip_mask_parent,
.irq_unmask = irq_chip_unmask_parent,
.irq_retrigger = irq_chip_retrigger_hierarchy,
.irq_set_type = irq_chip_set_type_parent,
.flags = IRQCHIP_MASK_ON_SUSPEND |
IRQCHIP_SKIP_SET_WAKE,
#ifdef CONFIG_SMP
.irq_set_affinity = irq_chip_set_affinity_parent,
#endif
};
static int allocate_gic_irq(struct irq_domain *domain, unsigned virq,
irq_hw_number_t hwirq)
{
struct irq_fwspec fwspec;
int i;
int err;
if (!irq_domain_get_of_node(domain->parent))
return -EINVAL;
raw_spin_lock(&cb->lock);
for (i = cb->int_max - 1; i >= 0; i--) {
if (cb->irq_map[i] == IRQ_FREE) {
cb->irq_map[i] = hwirq;
break;
}
}
raw_spin_unlock(&cb->lock);
if (i < 0)
return -ENODEV;
fwspec.fwnode = domain->parent->fwnode;
fwspec.param_count = 3;
fwspec.param[0] = 0; /* SPI */
fwspec.param[1] = i;
fwspec.param[2] = IRQ_TYPE_LEVEL_HIGH;
err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
if (err)
cb->irq_map[i] = IRQ_FREE;
else
cb->write(i, hwirq);
return err;
}
static int crossbar_domain_alloc(struct irq_domain *d, unsigned int virq,
unsigned int nr_irqs, void *data)
{
struct irq_fwspec *fwspec = data;
irq_hw_number_t hwirq;
int i;
if (fwspec->param_count != 3)
return -EINVAL; /* Not GIC compliant */
if (fwspec->param[0] != 0)
return -EINVAL; /* No PPI should point to this domain */
hwirq = fwspec->param[1];
if ((hwirq + nr_irqs) > cb->max_crossbar_sources)
return -EINVAL; /* Can't deal with this */
for (i = 0; i < nr_irqs; i++) {
int err = allocate_gic_irq(d, virq + i, hwirq + i);
if (err)
return err;
irq_domain_set_hwirq_and_chip(d, virq + i, hwirq + i,
&crossbar_chip, NULL);
}
return 0;
}
/**
* crossbar_domain_free - unmap/free a crossbar<->irq connection
* @domain: domain of irq to unmap
* @virq: virq number
* @nr_irqs: number of irqs to free
*
* We do not maintain a use count of total number of map/unmap
* calls for a particular irq to find out if a irq can be really
* unmapped. This is because unmap is called during irq_dispose_mapping(irq),
* after which irq is anyways unusable. So an explicit map has to be called
* after that.
*/
static void crossbar_domain_free(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs)
{
int i;
raw_spin_lock(&cb->lock);
for (i = 0; i < nr_irqs; i++) {
struct irq_data *d = irq_domain_get_irq_data(domain, virq + i);
irq_domain_reset_irq_data(d);
cb->irq_map[d->hwirq] = IRQ_FREE;
cb->write(d->hwirq, cb->safe_map);
}
raw_spin_unlock(&cb->lock);
}
static int crossbar_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
unsigned int *type)
{
if (is_of_node(fwspec->fwnode)) {
if (fwspec->param_count != 3)
return -EINVAL;
/* No PPI should point to this domain */
if (fwspec->param[0] != 0)
return -EINVAL;
*hwirq = fwspec->param[1];
*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
return 0;
}
return -EINVAL;
}
static const struct irq_domain_ops crossbar_domain_ops = {
.alloc = crossbar_domain_alloc,
.free = crossbar_domain_free,
.translate = crossbar_domain_translate,
};
static int __init crossbar_of_init(struct device_node *node)
{
int i, size, reserved = 0;
u32 max = 0, entry;
const __be32 *irqsr;
int ret = -ENOMEM;
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
if (!cb)
return ret;
cb->crossbar_base = of_iomap(node, 0);
if (!cb->crossbar_base)
goto err_cb;
of_property_read_u32(node, "ti,max-crossbar-sources",
&cb->max_crossbar_sources);
if (!cb->max_crossbar_sources) {
pr_err("missing 'ti,max-crossbar-sources' property\n");
ret = -EINVAL;
goto err_base;
}
of_property_read_u32(node, "ti,max-irqs", &max);
if (!max) {
pr_err("missing 'ti,max-irqs' property\n");
ret = -EINVAL;
goto err_base;
}
cb->irq_map = kcalloc(max, sizeof(int), GFP_KERNEL);
if (!cb->irq_map)
goto err_base;
cb->int_max = max;
for (i = 0; i < max; i++)
cb->irq_map[i] = IRQ_FREE;
/* Get and mark reserved irqs */
irqsr = of_get_property(node, "ti,irqs-reserved", &size);
if (irqsr) {
size /= sizeof(__be32);
for (i = 0; i < size; i++) {
of_property_read_u32_index(node,
"ti,irqs-reserved",
i, &entry);
if (entry >= max) {
pr_err("Invalid reserved entry\n");
ret = -EINVAL;
goto err_irq_map;
}
cb->irq_map[entry] = IRQ_RESERVED;
}
}
/* Skip irqs hardwired to bypass the crossbar */
irqsr = of_get_property(node, "ti,irqs-skip", &size);
if (irqsr) {
size /= sizeof(__be32);
for (i = 0; i < size; i++) {
of_property_read_u32_index(node,
"ti,irqs-skip",
i, &entry);
if (entry >= max) {
pr_err("Invalid skip entry\n");
ret = -EINVAL;
goto
|