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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Generic Event Device for ACPI.
*
* Copyright (c) 2016, The Linux Foundation. All rights reserved.
*
* Generic Event Device allows platforms to handle interrupts in ACPI
* ASL statements. It follows very similar to _EVT method approach
* from GPIO events. All interrupts are listed in _CRS and the handler
* is written in _EVT method. Here is an example.
*
* Device (GED0)
* {
*
* Name (_HID, "ACPI0013")
* Name (_UID, 0)
* Method (_CRS, 0x0, Serialized)
* {
* Name (RBUF, ResourceTemplate ()
* {
* Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )
* {123}
* }
* })
*
* Method (_EVT, 1) {
* if (Lequal(123, Arg0))
* {
* }
* }
* }
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/list.h>
#include <linux/platform_device.h>
#include <linux/acpi.h>
#define MODULE_NAME "acpi-ged"
struct acpi_ged_device {
struct device *dev;
struct list_head event_list;
};
struct acpi_ged_event {
struct list_head node;
struct device *dev;
unsigned int gsi;
unsigned int irq;
acpi_handle handle;
};
static irqreturn_t acpi_ged_irq_handler(int irq, void *data)
{
struct acpi_ged_event *event = data;
acpi_status acpi_ret;
acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);
if (ACPI_FAILURE(acpi_ret))
dev_err_once(event->dev, "IRQ method execution failed\n");
return IRQ_HANDLED;
}
static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
void *context)
{
struct acpi_ged_event *event;
unsigned int irq;
unsigned int gsi;
unsigned int irqflags = IRQF_ONESHOT;
struct acpi_ged_device *geddev = context;
struct device *dev = geddev->dev;
acpi_handle handle = ACPI_HANDLE(dev);
acpi_handle evt_handle;
struct resource r;
struct acpi_resource_irq *p = &ares->data.irq;
struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
char ev_name[5];
u8 trigger;
if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
return AE_OK;
if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
dev_err(dev, "unable to parse IRQ resource\n");
return AE_ERROR;
}
if (ares->type == ACPI_RESOURCE_TYPE_IRQ) {
gsi = p->interrupts[0];
trigger = p->triggering;
} else {
gsi = pext->interrupts[0];
trigger = pext->triggering;
}
irq = r.start;
switch (gsi) {
case 0 ... 255:
sprintf(ev_name, "_%c%02hhX",
trigger == ACPI_EDGE_SENSITIVE ? 'E' : 'L', gsi);
if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
break;
/* fall through */
default:
if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
break;
dev_err(dev, "cannot locate _EVT method\n");
return AE_ERROR;
}
event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
if (!event)
return AE_ERROR;
event->gsi = gsi;
event->dev = dev;
event->irq = irq;
event->handle = evt_handle;
if (r.flags & IORESOURCE_IRQ_SHAREABLE)
irqflags |= IRQF_SHARED;
if (request_threaded_irq(irq, NULL, acpi_ged_irq_handler,
irqflags, "ACPI:Ged", event)) {
dev_err(dev, "failed to setup event handler for irq %u\n", irq);
return AE_ERROR;
}
dev_dbg(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);
list_add_tail(&event->node, &geddev->event_list);
return AE_OK;
}
static int ged_probe(struct platform_device *pdev)
{
struct acpi_ged_device *geddev;
acpi_status acpi_ret;
geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL);
if (!geddev)
return -ENOMEM;
geddev->dev = &pdev->dev;
INIT_LIST_HEAD(&geddev->event_list);
acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
acpi_ged_request_interrupt, geddev);
if (ACPI_FAILURE(acpi_ret)) {
dev_err(&pdev->dev, "unable to parse the _CRS record\n");
return -EINVAL;
}
platform_set_drvdata(pdev, geddev);
return 0;
}
static void ged_shutdown(struct platform_device *pdev)
{
struct acpi_ged_device *geddev = platform_get_drvdata(pdev);
struct acpi_ged_event *event, *next;
list_for_each_entry_safe(event, next, &geddev->event_list, node) {
free_irq(event->irq, event);
list_del(&event->node);
dev_dbg(geddev->dev, "GED releasing GSI %u @ IRQ %u\n",
event->gsi, event->irq);
}
}
static int ged_remove(struct platform_device *pdev)
{
ged_shutdown(pdev);
return 0;
}
static const struct acpi_device_id ged_acpi_ids[] = {
{"ACPI0013"},
{},
};
static struct platform_driver ged_driver = {
.probe = ged_probe,
.remove = ged_remove,
.shutdown = ged_shutdown,
.driver = {
.name = MODULE_NAME,
.acpi_match_table = ACPI_PTR(ged_acpi_ids),
},
};
builtin_platform_driver(ged_driver);
|
