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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic Event Device for ACPI.
4 *
5 * Copyright (c) 2016, The Linux Foundation. All rights reserved.
6 *
7 * Generic Event Device allows platforms to handle interrupts in ACPI
8 * ASL statements. It follows very similar to _EVT method approach
9 * from GPIO events. All interrupts are listed in _CRS and the handler
10 * is written in _EVT method. Here is an example.
11 *
12 * Device (GED0)
13 * {
14 *
15 * Name (_HID, "ACPI0013")
16 * Name (_UID, 0)
17 * Method (_CRS, 0x0, Serialized)
18 * {
19 * Name (RBUF, ResourceTemplate ()
20 * {
21 * Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )
22 * {123}
23 * }
24 * })
25 *
26 * Method (_EVT, 1) {
27 * if (Lequal(123, Arg0))
28 * {
29 * }
30 * }
31 * }
32 */
33
34#include <linux/err.h>
35#include <linux/init.h>
36#include <linux/interrupt.h>
37#include <linux/list.h>
38#include <linux/platform_device.h>
39#include <linux/acpi.h>
40
41#define MODULE_NAME "acpi-ged"
42
43struct acpi_ged_device {
44 struct device *dev;
45 struct list_head event_list;
46};
47
48struct acpi_ged_event {
49 struct list_head node;
50 struct device *dev;
51 unsigned int gsi;
52 unsigned int irq;
53 acpi_handle handle;
54};
55
56static irqreturn_t acpi_ged_irq_handler(int irq, void *data)
57{
58 struct acpi_ged_event *event = data;
59 acpi_status acpi_ret;
60
61 acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);
62 if (ACPI_FAILURE(acpi_ret))
63 dev_err_once(event->dev, "IRQ method execution failed\n");
64
65 return IRQ_HANDLED;
66}
67
68static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
69 void *context)
70{
71 struct acpi_ged_event *event;
72 unsigned int irq;
73 unsigned int gsi;
74 unsigned int irqflags = IRQF_ONESHOT;
75 struct acpi_ged_device *geddev = context;
76 struct device *dev = geddev->dev;
77 acpi_handle handle = ACPI_HANDLE(dev);
78 acpi_handle evt_handle;
79 struct resource r;
80 struct acpi_resource_irq *p = &ares->data.irq;
81 struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
82
83 if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
84 return AE_OK;
85
86 if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
87 dev_err(dev, "unable to parse IRQ resource\n");
88 return AE_ERROR;
89 }
90 if (ares->type == ACPI_RESOURCE_TYPE_IRQ)
91 gsi = p->interrupts[0];
92 else
93 gsi = pext->interrupts[0];
94
95 irq = r.start;
96
97 if (ACPI_FAILURE(acpi_get_handle(handle, "_EVT", &evt_handle))) {
98 dev_err(dev, "cannot locate _EVT method\n");
99 return AE_ERROR;
100 }
101
102 event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
103 if (!event)
104 return AE_ERROR;
105
106 event->gsi = gsi;
107 event->dev = dev;
108 event->irq = irq;
109 event->handle = evt_handle;
110
111 if (r.flags & IORESOURCE_IRQ_SHAREABLE)
112 irqflags |= IRQF_SHARED;
113
114 if (request_threaded_irq(irq, NULL, acpi_ged_irq_handler,
115 irqflags, "ACPI:Ged", event)) {
116 dev_err(dev, "failed to setup event handler for irq %u\n", irq);
117 return AE_ERROR;
118 }
119
120 dev_dbg(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);
121 list_add_tail(&event->node, &geddev->event_list);
122 return AE_OK;
123}
124
125static int ged_probe(struct platform_device *pdev)
126{
127 struct acpi_ged_device *geddev;
128 acpi_status acpi_ret;
129
130 geddev = devm_kzalloc(&pdev->dev, sizeof(*geddev), GFP_KERNEL);
131 if (!geddev)
132 return -ENOMEM;
133
134 geddev->dev = &pdev->dev;
135 INIT_LIST_HEAD(&geddev->event_list);
136 acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
137 acpi_ged_request_interrupt, geddev);
138 if (ACPI_FAILURE(acpi_ret)) {
139 dev_err(&pdev->dev, "unable to parse the _CRS record\n");
140 return -EINVAL;
141 }
142 platform_set_drvdata(pdev, geddev);
143
144 return 0;
145}
146
147static void ged_shutdown(struct platform_device *pdev)
148{
149 struct acpi_ged_device *geddev = platform_get_drvdata(pdev);
150 struct acpi_ged_event *event, *next;
151
152 list_for_each_entry_safe(event, next, &geddev->event_list, node) {
153 free_irq(event->irq, event);
154 list_del(&event->node);
155 dev_dbg(geddev->dev, "GED releasing GSI %u @ IRQ %u\n",
156 event->gsi, event->irq);
157 }
158}
159
160static int ged_remove(struct platform_device *pdev)
161{
162 ged_shutdown(pdev);
163 return 0;
164}
165
166static const struct acpi_device_id ged_acpi_ids[] = {
167 {"ACPI0013"},
168 {},
169};
170
171static struct platform_driver ged_driver = {
172 .probe = ged_probe,
173 .remove = ged_remove,
174 .shutdown = ged_shutdown,
175 .driver = {
176 .name = MODULE_NAME,
177 .acpi_match_table = ACPI_PTR(ged_acpi_ids),
178 },
179};
180builtin_platform_driver(ged_driver);
1/*
2 * Generic Event Device for ACPI.
3 *
4 * Copyright (c) 2016, The Linux Foundation. All rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 and
8 * only version 2 as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * Generic Event Device allows platforms to handle interrupts in ACPI
16 * ASL statements. It follows very similar to _EVT method approach
17 * from GPIO events. All interrupts are listed in _CRS and the handler
18 * is written in _EVT method. Here is an example.
19 *
20 * Device (GED0)
21 * {
22 *
23 * Name (_HID, "ACPI0013")
24 * Name (_UID, 0)
25 * Method (_CRS, 0x0, Serialized)
26 * {
27 * Name (RBUF, ResourceTemplate ()
28 * {
29 * Interrupt(ResourceConsumer, Edge, ActiveHigh, Shared, , , )
30 * {123}
31 * }
32 * })
33 *
34 * Method (_EVT, 1) {
35 * if (Lequal(123, Arg0))
36 * {
37 * }
38 * }
39 * }
40 *
41 */
42
43#include <linux/err.h>
44#include <linux/init.h>
45#include <linux/interrupt.h>
46#include <linux/list.h>
47#include <linux/platform_device.h>
48#include <linux/acpi.h>
49
50#define MODULE_NAME "acpi-ged"
51
52struct acpi_ged_event {
53 struct list_head node;
54 struct device *dev;
55 unsigned int gsi;
56 unsigned int irq;
57 acpi_handle handle;
58};
59
60static irqreturn_t acpi_ged_irq_handler(int irq, void *data)
61{
62 struct acpi_ged_event *event = data;
63 acpi_status acpi_ret;
64
65 acpi_ret = acpi_execute_simple_method(event->handle, NULL, event->gsi);
66 if (ACPI_FAILURE(acpi_ret))
67 dev_err_once(event->dev, "IRQ method execution failed\n");
68
69 return IRQ_HANDLED;
70}
71
72static acpi_status acpi_ged_request_interrupt(struct acpi_resource *ares,
73 void *context)
74{
75 struct acpi_ged_event *event;
76 unsigned int irq;
77 unsigned int gsi;
78 unsigned int irqflags = IRQF_ONESHOT;
79 struct device *dev = context;
80 acpi_handle handle = ACPI_HANDLE(dev);
81 acpi_handle evt_handle;
82 struct resource r;
83 struct acpi_resource_irq *p = &ares->data.irq;
84 struct acpi_resource_extended_irq *pext = &ares->data.extended_irq;
85
86 if (ares->type == ACPI_RESOURCE_TYPE_END_TAG)
87 return AE_OK;
88
89 if (!acpi_dev_resource_interrupt(ares, 0, &r)) {
90 dev_err(dev, "unable to parse IRQ resource\n");
91 return AE_ERROR;
92 }
93 if (ares->type == ACPI_RESOURCE_TYPE_IRQ)
94 gsi = p->interrupts[0];
95 else
96 gsi = pext->interrupts[0];
97
98 irq = r.start;
99
100 if (ACPI_FAILURE(acpi_get_handle(handle, "_EVT", &evt_handle))) {
101 dev_err(dev, "cannot locate _EVT method\n");
102 return AE_ERROR;
103 }
104
105 dev_info(dev, "GED listening GSI %u @ IRQ %u\n", gsi, irq);
106
107 event = devm_kzalloc(dev, sizeof(*event), GFP_KERNEL);
108 if (!event)
109 return AE_ERROR;
110
111 event->gsi = gsi;
112 event->dev = dev;
113 event->irq = irq;
114 event->handle = evt_handle;
115
116 if (r.flags & IORESOURCE_IRQ_SHAREABLE)
117 irqflags |= IRQF_SHARED;
118
119 if (devm_request_threaded_irq(dev, irq, NULL, acpi_ged_irq_handler,
120 irqflags, "ACPI:Ged", event)) {
121 dev_err(dev, "failed to setup event handler for irq %u\n", irq);
122 return AE_ERROR;
123 }
124
125 return AE_OK;
126}
127
128static int ged_probe(struct platform_device *pdev)
129{
130 acpi_status acpi_ret;
131
132 acpi_ret = acpi_walk_resources(ACPI_HANDLE(&pdev->dev), "_CRS",
133 acpi_ged_request_interrupt, &pdev->dev);
134 if (ACPI_FAILURE(acpi_ret)) {
135 dev_err(&pdev->dev, "unable to parse the _CRS record\n");
136 return -EINVAL;
137 }
138
139 return 0;
140}
141
142static const struct acpi_device_id ged_acpi_ids[] = {
143 {"ACPI0013"},
144 {},
145};
146
147static struct platform_driver ged_driver = {
148 .probe = ged_probe,
149 .driver = {
150 .name = MODULE_NAME,
151 .acpi_match_table = ACPI_PTR(ged_acpi_ids),
152 },
153};
154builtin_platform_driver(ged_driver);