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 = kobject_create_and_add("tables", acpi_kobj);
 139         if (!tables_kobj)
 140                 return -ENOMEM;
 141
 142         do {
 143                 result = acpi_get_table_by_index(table_index, &table_header);
 144                 if (!result) {
 145                         table_index++;
 146                         table_attr = NULL;
 147                         table_attr =
 148                             kzalloc(sizeof(struct acpi_table_attr), GFP_KERNEL);
 149                         if (!table_attr)
 150                                 return -ENOMEM;
 151
 152                         acpi_table_attr_init(table_attr, table_header);
 153                         result =
 154                             sysfs_create_bin_file(tables_kobj,
 155                                                   &table_attr->attr);
 156                         if (result) {
 157                                 kfree(table_attr);
 158                                 return result;
 159                         } else
 160                                 list_add_tail(&table_attr->node,
 161                                               &acpi_table_attr_list);
 162                 }
 163         } while (!result);
 164         kobject_uevent(tables_kobj, KOBJ_ADD);
 165
 166         return 0;
 167 }
 168
 169 /* --------------------------------------------------------------------------
 170                               FS Interface (/proc)
 171    -------------------------------------------------------------------------- */
 172 #ifdef CONFIG_ACPI_PROCFS
 173 #define ACPI_SYSTEM_FILE_INFO           "info"
 174 #define ACPI_SYSTEM_FILE_EVENT          "event"
 175 #define ACPI_SYSTEM_FILE_DSDT           "dsdt"
 176 #define ACPI_SYSTEM_FILE_FADT           "fadt"
 177
 178 static int acpi_system_read_info(struct seq_file *seq, void *offset)
 179 {
 180
 181         seq_printf(seq, "version:                 %x\n", ACPI_CA_VERSION);
 182         return 0;
 183 }
 184
 185 static int acpi_system_info_open_fs(struct inode *inode, struct file *file)
 186 {
 187         return single_open(file, acpi_system_read_info, PDE(inode)->data);
 188 }
 189
 190 static const struct file_operations acpi_system_info_ops = {
 191         .open = acpi_system_info_open_fs,
 192         .read = seq_read,
 193         .llseek = seq_lseek,
 194         .release = single_release,
 195 };
 196
 197 static ssize_t acpi_system_read_dsdt(struct file *, char __user *, size_t,
 198                                      loff_t *);
 199
 200 static const struct file_operations acpi_system_dsdt_ops = {
 201         .read = acpi_system_read_dsdt,
 202 };
 203
 204 static ssize_t
 205 acpi_system_read_dsdt(struct file *file,
 206                       char __user * buffer, size_t count, loff_t * ppos)
 207 {
 208         acpi_status status = AE_OK;
 209         struct acpi_table_header *dsdt = NULL;
 210         ssize_t res;
 211
 212         status = acpi_get_table(ACPI_SIG_DSDT, 1, &dsdt);
 213         if (ACPI_FAILURE(status))
 214                 return -ENODEV;
 215
 216         res = simple_read_from_buffer(buffer, count, ppos, dsdt, dsdt->length);
 217
 218         return res;
 219 }
 220
 221 static ssize_t acpi_system_read_fadt(struct file *, char __user *, size_t,
 222                                      loff_t *);
 223
 224 static const struct file_operations acpi_system_fadt_ops = {
 225         .read = acpi_system_read_fadt,
 226 };
 227
 228 static ssize_t
 229 acpi_system_read_fadt(struct file *file,
 230                       char __user * buffer, size_t count, loff_t * ppos)
 231 {
 232         acpi_status status = AE_OK;
 233         struct acpi_table_header *fadt = NULL;
 234         ssize_t res;
 235
 236         status = acpi_get_table(ACPI_SIG_FADT, 1, &fadt);
 237         if (ACPI_FAILURE(status))
 238                 return -ENODEV;
 239
 240         res = simple_read_from_buffer(buffer, count, ppos, fadt, fadt->length);
 241
 242         return res;
 243 }
 244
 245 static int acpi_system_procfs_init(void)
 246 {
 247         struct proc_dir_entry *entry;
 248         int error = 0;
 249         char *name;
 250
 251         /* 'info' [R] */
 252         name = ACPI_SYSTEM_FILE_INFO;
 253         entry = create_proc_entry(name, S_IRUGO, acpi_root_dir);
 254         if (!entry)
 255                 goto Error;
 256         else {
 257                 entry->proc_fops = &acpi_system_info_ops;
 258         }
 259
 260         /* 'dsdt' [R] */
 261         name = ACPI_SYSTEM_FILE_DSDT;
 262         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 263         if (entry)
 264                 entry->proc_fops = &acpi_system_dsdt_ops;
 265         else
 266                 goto Error;
 267
 268         /* 'fadt' [R] */
 269         name = ACPI_SYSTEM_FILE_FADT;
 270         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 271         if (entry)
 272                 entry->proc_fops = &acpi_system_fadt_ops;
 273         else
 274                 goto Error;
 275
 276       Done:
 277         return error;
 278
 279       Error:
 280         remove_proc_entry(ACPI_SYSTEM_FILE_FADT, acpi_root_dir);
 281         remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_root_dir);
 282         remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_root_dir);
 283
 284         error = -EFAULT;
 285         goto Done;
 286 }
 287 #else
 288 static int acpi_system_procfs_init(void)
 289 {
 290         return 0;
 291 }
 292 #endif
 293
 294 static int __init acpi_system_init(void)
 295 {
 296         int result = 0;
 297
 298         if (acpi_disabled)
 299                 return 0;
 300
 301         result = acpi_system_procfs_init();
 302         if (result)
 303                 return result;
 304
 305         result = acpi_system_sysfs_init();
 306
 307         return result;
 308 }
 309
 310 subsys_initcall(acpi_system_init);