drivers/acpi/system.c

   1 /*
   2  *  acpi_system.c - ACPI System Driver ($Revision: 63 $)
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License along
  20  *  with this program; if not, write to the Free Software Foundation, Inc.,
  21  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/proc_fs.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/init.h>
  29 #include <asm/uaccess.h>
  30
  31 #include <acpi/acpi_drivers.h>
  32
  33 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  34 ACPI_MODULE_NAME("system");
  35 #ifdef MODULE_PARAM_PREFIX
  36 #undef MODULE_PARAM_PREFIX
  37 #endif
  38 #define MODULE_PARAM_PREFIX "acpi."
  39
  40 #define ACPI_SYSTEM_CLASS               "system"
  41 #define ACPI_SYSTEM_DEVICE_NAME         "System"
  42
  43 /*
  44  * Make ACPICA version work as module param
  45  */
  46 static int param_get_acpica_version(char *buffer, struct kernel_param *kp)
  47 {
  48         int result;
  49
  50         result = sprintf(buffer, "%x", ACPI_CA_VERSION);
  51
  52         return result;
  53 }
  54
  55 module_param_call(acpica_version, NULL, param_get_acpica_version, NULL, 0444);
  56
  57 /* --------------------------------------------------------------------------
  58                               FS Interface (/sys)
  59    -------------------------------------------------------------------------- */
  60 static LIST_HEAD(acpi_table_attr_list);
  61 static struct kobject tables_kobj;
  62
  63 struct acpi_table_attr {
  64         struct bin_attribute attr;
  65         char name[8];
  66         int instance;
  67         struct list_head node;
  68 };
  69
  70 static ssize_t acpi_table_show(struct kobject *kobj,
  71                                struct bin_attribute *bin_attr, char *buf,
  72                                loff_t offset, size_t count)
  73 {
  74         struct acpi_table_attr *table_attr =
  75             container_of(bin_attr, struct acpi_table_attr, attr);
  76         struct acpi_table_header *table_header = NULL;
  77         acpi_status status;
  78         ssize_t ret_count = count;
  79
  80         status =
  81             acpi_get_table(table_attr->name, table_attr->instance,
  82                            &table_header);
  83         if (ACPI_FAILURE(status))
  84                 return -ENODEV;
  85
  86         if (offset >= table_header->length) {
  87                 ret_count = 0;
  88                 goto end;
  89         }
  90
  91         if (offset + ret_count > table_header->length)
  92                 ret_count = table_header->length - offset;
  93
  94         memcpy(buf, ((char *)table_header) + offset, ret_count);
  95
  96       end:
  97         return ret_count;
  98 }
  99
 100 static void acpi_table_attr_init(struct acpi_table_attr *table_attr,
 101                                  struct acpi_table_header *table_header)
 102 {
 103         struct acpi_table_header *header = NULL;
 104         struct acpi_table_attr *attr = NULL;
 105
 106         memcpy(table_attr->name, table_header->signature, ACPI_NAME_SIZE);
 107
 108         list_for_each_entry(attr, &acpi_table_attr_list, node) {
 109                 if (!memcmp(table_header->signature, attr->name,
 110                             ACPI_NAME_SIZE))
 111                         if (table_attr->instance < attr->instance)
 112                                 table_attr->instance = attr->instance;
 113         }
 114         table_attr->instance++;
 115
 116         if (table_attr->instance > 1 || (table_attr->instance == 1 &&
 117                                          !acpi_get_table(table_header->
 118                                                          signature, 2,
 119                                                          &header)))
 120                 sprintf(table_attr->name + 4, "%d", table_attr->instance);
 121
 122         table_attr->attr.size = 0;
 123         table_attr->attr.read = acpi_table_show;
 124         table_attr->attr.attr.name = table_attr->name;
 125         table_attr->attr.attr.mode = 0444;
 126         table_attr->attr.attr.owner = THIS_MODULE;
 127
 128         return;
 129 }
 130
 131 static int acpi_system_sysfs_init(void)
 132 {
 133         struct acpi_table_attr *table_attr;
 134         struct acpi_table_header *table_header = NULL;
 135         int table_index = 0;
 136         int result;
 137
 138         tables_kobj.parent = &acpi_subsys.kobj;
 139         kobject_set_name(&tables_kobj, "tables");
 140         result = kobject_register(&tables_kobj);
 141         if (result)
 142                 return result;
 143
 144         do {
 145                 result = acpi_get_table_by_index(table_index, &table_header);
 146                 if (!result) {
 147                         table_index++;
 148                         table_attr = NULL;
 149                         table_attr =
 150                             kzalloc(sizeof(struct acpi_table_attr), GFP_KERNEL);
 151                         if (!table_attr)
 152                                 return -ENOMEM;
 153
 154                         acpi_table_attr_init(table_attr, table_header);
 155                         result =
 156                             sysfs_create_bin_file(&tables_kobj,
 157                                                   &table_attr->attr);
 158                         if (result) {
 159                                 kfree(table_attr);
 160                                 return result;
 161                         } else
 162                                 list_add_tail(&table_attr->node,
 163                                               &acpi_table_attr_list);
 164                 }
 165         } while (!result);
 166
 167         return 0;
 168 }
 169
 170 /* --------------------------------------------------------------------------
 171                               FS Interface (/proc)
 172    -------------------------------------------------------------------------- */
 173 #ifdef CONFIG_ACPI_PROCFS
 174 #define ACPI_SYSTEM_FILE_INFO           "info"
 175 #define ACPI_SYSTEM_FILE_EVENT          "event"
 176 #define ACPI_SYSTEM_FILE_DSDT           "dsdt"
 177 #define ACPI_SYSTEM_FILE_FADT           "fadt"
 178
 179 static int acpi_system_read_info(struct seq_file *seq, void *offset)
 180 {
 181
 182         seq_printf(seq, "version:                 %x\n", ACPI_CA_VERSION);
 183         return 0;
 184 }
 185
 186 static int acpi_system_info_open_fs(struct inode *inode, struct file *file)
 187 {
 188         return single_open(file, acpi_system_read_info, PDE(inode)->data);
 189 }
 190
 191 static const struct file_operations acpi_system_info_ops = {
 192         .open = acpi_system_info_open_fs,
 193         .read = seq_read,
 194         .llseek = seq_lseek,
 195         .release = single_release,
 196 };
 197
 198 static ssize_t acpi_system_read_dsdt(struct file *, char __user *, size_t,
 199                                      loff_t *);
 200
 201 static const struct file_operations acpi_system_dsdt_ops = {
 202         .read = acpi_system_read_dsdt,
 203 };
 204
 205 static ssize_t
 206 acpi_system_read_dsdt(struct file *file,
 207                       char __user * buffer, size_t count, loff_t * ppos)
 208 {
 209         acpi_status status = AE_OK;
 210         struct acpi_table_header *dsdt = NULL;
 211         ssize_t res;
 212
 213         status = acpi_get_table(ACPI_SIG_DSDT, 1, &dsdt);
 214         if (ACPI_FAILURE(status))
 215                 return -ENODEV;
 216
 217         res = simple_read_from_buffer(buffer, count, ppos, dsdt, dsdt->length);
 218
 219         return res;
 220 }
 221
 222 static ssize_t acpi_system_read_fadt(struct file *, char __user *, size_t,
 223                                      loff_t *);
 224
 225 static const struct file_operations acpi_system_fadt_ops = {
 226         .read = acpi_system_read_fadt,
 227 };
 228
 229 static ssize_t
 230 acpi_system_read_fadt(struct file *file,
 231                       char __user * buffer, size_t count, loff_t * ppos)
 232 {
 233         acpi_status status = AE_OK;
 234         struct acpi_table_header *fadt = NULL;
 235         ssize_t res;
 236
 237         status = acpi_get_table(ACPI_SIG_FADT, 1, &fadt);
 238         if (ACPI_FAILURE(status))
 239                 return -ENODEV;
 240
 241         res = simple_read_from_buffer(buffer, count, ppos, fadt, fadt->length);
 242
 243         return res;
 244 }
 245
 246 static int acpi_system_procfs_init(void)
 247 {
 248         struct proc_dir_entry *entry;
 249         int error = 0;
 250         char *name;
 251
 252         /* 'info' [R] */
 253         name = ACPI_SYSTEM_FILE_INFO;
 254         entry = create_proc_entry(name, S_IRUGO, acpi_root_dir);
 255         if (!entry)
 256                 goto Error;
 257         else {
 258                 entry->proc_fops = &acpi_system_info_ops;
 259         }
 260
 261         /* 'dsdt' [R] */
 262         name = ACPI_SYSTEM_FILE_DSDT;
 263         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 264         if (entry)
 265                 entry->proc_fops = &acpi_system_dsdt_ops;
 266         else
 267                 goto Error;
 268
 269         /* 'fadt' [R] */
 270         name = ACPI_SYSTEM_FILE_FADT;
 271         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 272         if (entry)
 273                 entry->proc_fops = &acpi_system_fadt_ops;
 274         else
 275                 goto Error;
 276
 277       Done:
 278         return error;
 279
 280       Error:
 281         remove_proc_entry(ACPI_SYSTEM_FILE_FADT, acpi_root_dir);
 282         remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_root_dir);
 283         remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_root_dir);
 284
 285         error = -EFAULT;
 286         goto Done;
 287 }
 288 #else
 289 static int acpi_system_procfs_init(void)
 290 {
 291         return 0;
 292 }
 293 #endif
 294
 295 static int __init acpi_system_init(void)
 296 {
 297         int result = 0;
 298
 299         if (acpi_disabled)
 300                 return 0;
 301
 302         result = acpi_system_procfs_init();
 303         if (result)
 304                 return result;
 305
 306         result = acpi_system_sysfs_init();
 307
 308         return result;
 309 }
 310
 311 subsys_initcall(acpi_system_init);