xref: /linux/drivers/acpi/container.c (revision 6ed7ffddcf61f668114edb676417e5fb33773b59)
1 /*
2  * acpi_container.c  - ACPI Generic Container Driver
3  * ($Revision: )
4  *
5  * Copyright (C) 2004 Anil S Keshavamurthy (anil.s.keshavamurthy@intel.com)
6  * Copyright (C) 2004 Keiichiro Tokunaga (tokunaga.keiich@jp.fujitsu.com)
7  * Copyright (C) 2004 Motoyuki Ito (motoyuki@soft.fujitsu.com)
8  * Copyright (C) 2004 Intel Corp.
9  * Copyright (C) 2004 FUJITSU LIMITED
10  *
11  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12  *
13  *  This program is free software; you can redistribute it and/or modify
14  *  it under the terms of the GNU General Public License as published by
15  *  the Free Software Foundation; either version 2 of the License, or (at
16  *  your option) any later version.
17  *
18  *  This program is distributed in the hope that it will be useful, but
19  *  WITHOUT ANY WARRANTY; without even the implied warranty of
20  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21  *  General Public License for more details.
22  *
23  *  You should have received a copy of the GNU General Public License along
24  *  with this program; if not, write to the Free Software Foundation, Inc.,
25  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
26  *
27  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
28  */
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/slab.h>
33 #include <linux/types.h>
34 #include <linux/acpi.h>
35 #include <acpi/acpi_bus.h>
36 #include <acpi/acpi_drivers.h>
37 
38 #define PREFIX "ACPI: "
39 
40 #define _COMPONENT			ACPI_CONTAINER_COMPONENT
41 ACPI_MODULE_NAME("container");
42 
43 static const struct acpi_device_id container_device_ids[] = {
44 	{"ACPI0004", 0},
45 	{"PNP0A05", 0},
46 	{"PNP0A06", 0},
47 	{"", 0},
48 };
49 
50 static int container_device_attach(struct acpi_device *device,
51 				   const struct acpi_device_id *not_used)
52 {
53 	/*
54 	 * FIXME: This is necessary, so that acpi_eject_store() doesn't return
55 	 * -ENODEV for containers.
56 	 */
57 	return 1;
58 }
59 
60 static struct acpi_scan_handler container_device_handler = {
61 	.ids = container_device_ids,
62 	.attach = container_device_attach,
63 };
64 
65 static int is_device_present(acpi_handle handle)
66 {
67 	acpi_handle temp;
68 	acpi_status status;
69 	unsigned long long sta;
70 
71 
72 	status = acpi_get_handle(handle, "_STA", &temp);
73 	if (ACPI_FAILURE(status))
74 		return 1;	/* _STA not found, assume device present */
75 
76 	status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
77 	if (ACPI_FAILURE(status))
78 		return 0;	/* Firmware error */
79 
80 	return ((sta & ACPI_STA_DEVICE_PRESENT) == ACPI_STA_DEVICE_PRESENT);
81 }
82 
83 static void container_notify_cb(acpi_handle handle, u32 type, void *context)
84 {
85 	struct acpi_device *device = NULL;
86 	int result;
87 	int present;
88 	acpi_status status;
89 	u32 ost_code = ACPI_OST_SC_NON_SPECIFIC_FAILURE; /* default */
90 
91 	acpi_scan_lock_acquire();
92 
93 	switch (type) {
94 	case ACPI_NOTIFY_BUS_CHECK:
95 		/* Fall through */
96 	case ACPI_NOTIFY_DEVICE_CHECK:
97 		pr_debug("Container driver received %s event\n",
98 		       (type == ACPI_NOTIFY_BUS_CHECK) ?
99 		       "ACPI_NOTIFY_BUS_CHECK" : "ACPI_NOTIFY_DEVICE_CHECK");
100 
101 		present = is_device_present(handle);
102 		status = acpi_bus_get_device(handle, &device);
103 		if (!present) {
104 			if (ACPI_SUCCESS(status)) {
105 				/* device exist and this is a remove request */
106 				device->flags.eject_pending = 1;
107 				kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
108 				goto out;
109 			}
110 			break;
111 		}
112 
113 		if (!ACPI_FAILURE(status) || device)
114 			break;
115 
116 		result = acpi_bus_scan(handle);
117 		if (result) {
118 			acpi_handle_warn(handle, "Failed to add container\n");
119 			break;
120 		}
121 		result = acpi_bus_get_device(handle, &device);
122 		if (result) {
123 			acpi_handle_warn(handle, "Missing device object\n");
124 			break;
125 		}
126 
127 		kobject_uevent(&device->dev.kobj, KOBJ_ONLINE);
128 		ost_code = ACPI_OST_SC_SUCCESS;
129 		break;
130 
131 	case ACPI_NOTIFY_EJECT_REQUEST:
132 		if (!acpi_bus_get_device(handle, &device) && device) {
133 			device->flags.eject_pending = 1;
134 			kobject_uevent(&device->dev.kobj, KOBJ_OFFLINE);
135 			goto out;
136 		}
137 		break;
138 
139 	default:
140 		/* non-hotplug event; possibly handled by other handler */
141 		goto out;
142 	}
143 
144 	/* Inform firmware that the hotplug operation has completed */
145 	(void) acpi_evaluate_hotplug_ost(handle, type, ost_code, NULL);
146 
147  out:
148 	acpi_scan_lock_release();
149 }
150 
151 static bool is_container(acpi_handle handle)
152 {
153 	struct acpi_device_info *info;
154 	bool ret = false;
155 
156 	if (ACPI_FAILURE(acpi_get_object_info(handle, &info)))
157 		return false;
158 
159 	if (info->valid & ACPI_VALID_HID) {
160 		const struct acpi_device_id *id;
161 
162 		for (id = container_device_ids; id->id[0]; id++) {
163 			ret = !strcmp((char *)id->id, info->hardware_id.string);
164 			if (ret)
165 				break;
166 		}
167 	}
168 	kfree(info);
169 	return ret;
170 }
171 
172 static acpi_status acpi_container_register_notify_handler(acpi_handle handle,
173 							  u32 lvl, void *ctxt,
174 							  void **retv)
175 {
176 	if (is_container(handle))
177 		acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
178 					    container_notify_cb, NULL);
179 
180 	return AE_OK;
181 }
182 
183 void __init acpi_container_init(void)
184 {
185 	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
186 			    acpi_container_register_notify_handler, NULL,
187 			    NULL, NULL);
188 
189 	acpi_scan_add_handler(&container_device_handler);
190 }
191