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("acpi_system")
  35 #define ACPI_SYSTEM_CLASS               "system"
  36 #define ACPI_SYSTEM_DRIVER_NAME         "ACPI System Driver"
  37 #define ACPI_SYSTEM_DEVICE_NAME         "System"
  38 #define ACPI_SYSTEM_FILE_INFO           "info"
  39 #define ACPI_SYSTEM_FILE_EVENT          "event"
  40 #define ACPI_SYSTEM_FILE_DSDT           "dsdt"
  41 #define ACPI_SYSTEM_FILE_FADT           "fadt"
  42 extern FADT_DESCRIPTOR acpi_fadt;
  43
  44 /* --------------------------------------------------------------------------
  45                               FS Interface (/proc)
  46    -------------------------------------------------------------------------- */
  47
  48 static int acpi_system_read_info(struct seq_file *seq, void *offset)
  49 {
  50         ACPI_FUNCTION_TRACE("acpi_system_read_info");
  51
  52         seq_printf(seq, "version:                 %x\n", ACPI_CA_VERSION);
  53         return_VALUE(0);
  54 }
  55
  56 static int acpi_system_info_open_fs(struct inode *inode, struct file *file)
  57 {
  58         return single_open(file, acpi_system_read_info, PDE(inode)->data);
  59 }
  60
  61 static struct file_operations acpi_system_info_ops = {
  62         .open = acpi_system_info_open_fs,
  63         .read = seq_read,
  64         .llseek = seq_lseek,
  65         .release = single_release,
  66 };
  67
  68 static ssize_t acpi_system_read_dsdt(struct file *, char __user *, size_t,
  69                                      loff_t *);
  70
  71 static struct file_operations acpi_system_dsdt_ops = {
  72         .read = acpi_system_read_dsdt,
  73 };
  74
  75 static ssize_t
  76 acpi_system_read_dsdt(struct file *file,
  77                       char __user * buffer, size_t count, loff_t * ppos)
  78 {
  79         acpi_status status = AE_OK;
  80         struct acpi_buffer dsdt = { ACPI_ALLOCATE_BUFFER, NULL };
  81         ssize_t res;
  82
  83         ACPI_FUNCTION_TRACE("acpi_system_read_dsdt");
  84
  85         status = acpi_get_table(ACPI_TABLE_DSDT, 1, &dsdt);
  86         if (ACPI_FAILURE(status))
  87                 return_VALUE(-ENODEV);
  88
  89         res = simple_read_from_buffer(buffer, count, ppos,
  90                                       dsdt.pointer, dsdt.length);
  91         acpi_os_free(dsdt.pointer);
  92
  93         return_VALUE(res);
  94 }
  95
  96 static ssize_t acpi_system_read_fadt(struct file *, char __user *, size_t,
  97                                      loff_t *);
  98
  99 static struct file_operations acpi_system_fadt_ops = {
 100         .read = acpi_system_read_fadt,
 101 };
 102
 103 static ssize_t
 104 acpi_system_read_fadt(struct file *file,
 105                       char __user * buffer, size_t count, loff_t * ppos)
 106 {
 107         acpi_status status = AE_OK;
 108         struct acpi_buffer fadt = { ACPI_ALLOCATE_BUFFER, NULL };
 109         ssize_t res;
 110
 111         ACPI_FUNCTION_TRACE("acpi_system_read_fadt");
 112
 113         status = acpi_get_table(ACPI_TABLE_FADT, 1, &fadt);
 114         if (ACPI_FAILURE(status))
 115                 return_VALUE(-ENODEV);
 116
 117         res = simple_read_from_buffer(buffer, count, ppos,
 118                                       fadt.pointer, fadt.length);
 119         acpi_os_free(fadt.pointer);
 120
 121         return_VALUE(res);
 122 }
 123
 124 static int __init acpi_system_init(void)
 125 {
 126         struct proc_dir_entry *entry;
 127         int error = 0;
 128         char *name;
 129
 130         ACPI_FUNCTION_TRACE("acpi_system_init");
 131
 132         if (acpi_disabled)
 133                 return_VALUE(0);
 134
 135         /* 'info' [R] */
 136         name = ACPI_SYSTEM_FILE_INFO;
 137         entry = create_proc_entry(name, S_IRUGO, acpi_root_dir);
 138         if (!entry)
 139                 goto Error;
 140         else {
 141                 entry->proc_fops = &acpi_system_info_ops;
 142         }
 143
 144         /* 'dsdt' [R] */
 145         name = ACPI_SYSTEM_FILE_DSDT;
 146         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 147         if (entry)
 148                 entry->proc_fops = &acpi_system_dsdt_ops;
 149         else
 150                 goto Error;
 151
 152         /* 'fadt' [R] */
 153         name = ACPI_SYSTEM_FILE_FADT;
 154         entry = create_proc_entry(name, S_IRUSR, acpi_root_dir);
 155         if (entry)
 156                 entry->proc_fops = &acpi_system_fadt_ops;
 157         else
 158                 goto Error;
 159
 160       Done:
 161         return_VALUE(error);
 162
 163       Error:
 164         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 165                           "Unable to create '%s' proc fs entry\n", name));
 166
 167         remove_proc_entry(ACPI_SYSTEM_FILE_FADT, acpi_root_dir);
 168         remove_proc_entry(ACPI_SYSTEM_FILE_DSDT, acpi_root_dir);
 169         remove_proc_entry(ACPI_SYSTEM_FILE_INFO, acpi_root_dir);
 170
 171         error = -EFAULT;
 172         goto Done;
 173 }
 174
 175 subsys_initcall(acpi_system_init);