1 /* 2 * Link physical devices with ACPI devices support 3 * 4 * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com> 5 * Copyright (c) 2005 Intel Corp. 6 * 7 * This file is released under the GPLv2. 8 */ 9 #include <linux/init.h> 10 #include <linux/list.h> 11 #include <linux/device.h> 12 #include <linux/rwsem.h> 13 #include <linux/acpi.h> 14 15 #define ACPI_GLUE_DEBUG 0 16 #if ACPI_GLUE_DEBUG 17 #define DBG(x...) printk(PREFIX x) 18 #else 19 #define DBG(x...) do { } while(0) 20 #endif 21 static LIST_HEAD(bus_type_list); 22 static DECLARE_RWSEM(bus_type_sem); 23 24 int register_acpi_bus_type(struct acpi_bus_type *type) 25 { 26 if (acpi_disabled) 27 return -ENODEV; 28 if (type && type->bus && type->find_device) { 29 down_write(&bus_type_sem); 30 list_add_tail(&type->list, &bus_type_list); 31 up_write(&bus_type_sem); 32 printk(KERN_INFO PREFIX "bus type %s registered\n", 33 type->bus->name); 34 return 0; 35 } 36 return -ENODEV; 37 } 38 39 int unregister_acpi_bus_type(struct acpi_bus_type *type) 40 { 41 if (acpi_disabled) 42 return 0; 43 if (type) { 44 down_write(&bus_type_sem); 45 list_del_init(&type->list); 46 up_write(&bus_type_sem); 47 printk(KERN_INFO PREFIX "ACPI bus type %s unregistered\n", 48 type->bus->name); 49 return 0; 50 } 51 return -ENODEV; 52 } 53 54 static struct acpi_bus_type *acpi_get_bus_type(struct bus_type *type) 55 { 56 struct acpi_bus_type *tmp, *ret = NULL; 57 58 down_read(&bus_type_sem); 59 list_for_each_entry(tmp, &bus_type_list, list) { 60 if (tmp->bus == type) { 61 ret = tmp; 62 break; 63 } 64 } 65 up_read(&bus_type_sem); 66 return ret; 67 } 68 69 static int acpi_find_bridge_device(struct device *dev, acpi_handle * handle) 70 { 71 struct acpi_bus_type *tmp; 72 int ret = -ENODEV; 73 74 down_read(&bus_type_sem); 75 list_for_each_entry(tmp, &bus_type_list, list) { 76 if (tmp->find_bridge && !tmp->find_bridge(dev, handle)) { 77 ret = 0; 78 break; 79 } 80 } 81 up_read(&bus_type_sem); 82 return ret; 83 } 84 85 /* Get device's handler per its address under its parent */ 86 struct acpi_find_child { 87 acpi_handle handle; 88 acpi_integer address; 89 }; 90 91 static acpi_status 92 do_acpi_find_child(acpi_handle handle, u32 lvl, void *context, void **rv) 93 { 94 acpi_status status; 95 struct acpi_device_info *info; 96 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 97 struct acpi_find_child *find = context; 98 99 status = acpi_get_object_info(handle, &buffer); 100 if (ACPI_SUCCESS(status)) { 101 info = buffer.pointer; 102 if (info->address == find->address) 103 find->handle = handle; 104 kfree(buffer.pointer); 105 } 106 return AE_OK; 107 } 108 109 acpi_handle acpi_get_child(acpi_handle parent, acpi_integer address) 110 { 111 struct acpi_find_child find = { NULL, address }; 112 113 if (!parent) 114 return NULL; 115 acpi_walk_namespace(ACPI_TYPE_DEVICE, parent, 116 1, do_acpi_find_child, &find, NULL); 117 return find.handle; 118 } 119 120 EXPORT_SYMBOL(acpi_get_child); 121 122 /* Link ACPI devices with physical devices */ 123 static void acpi_glue_data_handler(acpi_handle handle, 124 u32 function, void *context) 125 { 126 /* we provide an empty handler */ 127 } 128 129 /* Note: a success call will increase reference count by one */ 130 struct device *acpi_get_physical_device(acpi_handle handle) 131 { 132 acpi_status status; 133 struct device *dev; 134 135 status = acpi_get_data(handle, acpi_glue_data_handler, (void **)&dev); 136 if (ACPI_SUCCESS(status)) 137 return get_device(dev); 138 return NULL; 139 } 140 141 EXPORT_SYMBOL(acpi_get_physical_device); 142 143 static int acpi_bind_one(struct device *dev, acpi_handle handle) 144 { 145 struct acpi_device *acpi_dev; 146 acpi_status status; 147 148 if (dev->archdata.acpi_handle) { 149 dev_warn(dev, "Drivers changed 'acpi_handle'\n"); 150 return -EINVAL; 151 } 152 get_device(dev); 153 status = acpi_attach_data(handle, acpi_glue_data_handler, dev); 154 if (ACPI_FAILURE(status)) { 155 put_device(dev); 156 return -EINVAL; 157 } 158 dev->archdata.acpi_handle = handle; 159 160 status = acpi_bus_get_device(handle, &acpi_dev); 161 if (!ACPI_FAILURE(status)) { 162 int ret; 163 164 ret = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, 165 "firmware_node"); 166 ret = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, 167 "physical_node"); 168 if (acpi_dev->wakeup.flags.valid) { 169 device_set_wakeup_capable(dev, true); 170 device_set_wakeup_enable(dev, 171 acpi_dev->wakeup.state.enabled); 172 } 173 } 174 175 return 0; 176 } 177 178 static int acpi_unbind_one(struct device *dev) 179 { 180 if (!dev->archdata.acpi_handle) 181 return 0; 182 if (dev == acpi_get_physical_device(dev->archdata.acpi_handle)) { 183 struct acpi_device *acpi_dev; 184 185 /* acpi_get_physical_device increase refcnt by one */ 186 put_device(dev); 187 188 if (!acpi_bus_get_device(dev->archdata.acpi_handle, 189 &acpi_dev)) { 190 sysfs_remove_link(&dev->kobj, "firmware_node"); 191 sysfs_remove_link(&acpi_dev->dev.kobj, "physical_node"); 192 } 193 194 acpi_detach_data(dev->archdata.acpi_handle, 195 acpi_glue_data_handler); 196 dev->archdata.acpi_handle = NULL; 197 /* acpi_bind_one increase refcnt by one */ 198 put_device(dev); 199 } else { 200 dev_err(dev, "Oops, 'acpi_handle' corrupt\n"); 201 } 202 return 0; 203 } 204 205 static int acpi_platform_notify(struct device *dev) 206 { 207 struct acpi_bus_type *type; 208 acpi_handle handle; 209 int ret = -EINVAL; 210 211 if (!dev->bus || !dev->parent) { 212 /* bridge devices genernally haven't bus or parent */ 213 ret = acpi_find_bridge_device(dev, &handle); 214 goto end; 215 } 216 type = acpi_get_bus_type(dev->bus); 217 if (!type) { 218 DBG("No ACPI bus support for %s\n", dev_name(dev)); 219 ret = -EINVAL; 220 goto end; 221 } 222 if ((ret = type->find_device(dev, &handle)) != 0) 223 DBG("Can't get handler for %s\n", dev_name(dev)); 224 end: 225 if (!ret) 226 acpi_bind_one(dev, handle); 227 228 #if ACPI_GLUE_DEBUG 229 if (!ret) { 230 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 231 232 acpi_get_name(dev->archdata.acpi_handle, 233 ACPI_FULL_PATHNAME, &buffer); 234 DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer); 235 kfree(buffer.pointer); 236 } else 237 DBG("Device %s -> No ACPI support\n", dev_name(dev)); 238 #endif 239 240 return ret; 241 } 242 243 static int acpi_platform_notify_remove(struct device *dev) 244 { 245 acpi_unbind_one(dev); 246 return 0; 247 } 248 249 int __init init_acpi_device_notify(void) 250 { 251 if (platform_notify || platform_notify_remove) { 252 printk(KERN_ERR PREFIX "Can't use platform_notify\n"); 253 return 0; 254 } 255 platform_notify = acpi_platform_notify; 256 platform_notify_remove = acpi_platform_notify_remove; 257 return 0; 258 } 259