drivers/acpi/debug.c

   1 /*
   2  * debug.c - ACPI debug interface to userspace.
   3  */
   4
   5 #include <linux/proc_fs.h>
   6 #include <linux/init.h>
   7 #include <asm/uaccess.h>
   8 #include <acpi/acpi_drivers.h>
   9
  10 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  11 ACPI_MODULE_NAME                ("debug")
  12
  13 #define ACPI_SYSTEM_FILE_DEBUG_LAYER    "debug_layer"
  14 #define ACPI_SYSTEM_FILE_DEBUG_LEVEL    "debug_level"
  15
  16 static int
  17 acpi_system_read_debug (
  18         char                    *page,
  19         char                    **start,
  20         off_t                   off,
  21         int                     count,
  22         int                     *eof,
  23         void                    *data)
  24 {
  25         char                    *p = page;
  26         int                     size = 0;
  27
  28         if (off != 0)
  29                 goto end;
  30
  31         switch ((unsigned long) data) {
  32         case 0:
  33                 p += sprintf(p, "0x%08x\n", acpi_dbg_layer);
  34                 break;
  35         case 1:
  36                 p += sprintf(p, "0x%08x\n", acpi_dbg_level);
  37                 break;
  38         default:
  39                 p += sprintf(p, "Invalid debug option\n");
  40                 break;
  41         }
  42
  43 end:
  44         size = (p - page);
  45         if (size <= off+count) *eof = 1;
  46         *start = page + off;
  47         size -= off;
  48         if (size>count) size = count;
  49         if (size<0) size = 0;
  50
  51         return size;
  52 }
  53
  54
  55 static int
  56 acpi_system_write_debug (
  57         struct file             *file,
  58         const char              __user *buffer,
  59         unsigned long           count,
  60         void                    *data)
  61 {
  62         char                    debug_string[12] = {'\0'};
  63
  64         ACPI_FUNCTION_TRACE("acpi_system_write_debug");
  65
  66         if (count > sizeof(debug_string) - 1)
  67                 return_VALUE(-EINVAL);
  68
  69         if (copy_from_user(debug_string, buffer, count))
  70                 return_VALUE(-EFAULT);
  71
  72         debug_string[count] = '\0';
  73
  74         switch ((unsigned long) data) {
  75         case 0:
  76                 acpi_dbg_layer = simple_strtoul(debug_string, NULL, 0);
  77                 break;
  78         case 1:
  79                 acpi_dbg_level = simple_strtoul(debug_string, NULL, 0);
  80                 break;
  81         default:
  82                 return_VALUE(-EINVAL);
  83         }
  84
  85         return_VALUE(count);
  86 }
  87
  88 static int __init acpi_debug_init(void)
  89 {
  90         struct proc_dir_entry   *entry;
  91         int error = 0;
  92         char * name;
  93
  94         ACPI_FUNCTION_TRACE("acpi_debug_init");
  95
  96         if (acpi_disabled)
  97                 return_VALUE(0);
  98
  99         /* 'debug_layer' [R/W] */
 100         name = ACPI_SYSTEM_FILE_DEBUG_LAYER;
 101         entry = create_proc_read_entry(name, S_IFREG|S_IRUGO|S_IWUSR, acpi_root_dir,
 102                                        acpi_system_read_debug,(void *)0);
 103         if (entry)
 104                 entry->write_proc = acpi_system_write_debug;
 105         else
 106                 goto Error;
 107
 108         /* 'debug_level' [R/W] */
 109         name = ACPI_SYSTEM_FILE_DEBUG_LEVEL;
 110         entry = create_proc_read_entry(name, S_IFREG|S_IRUGO|S_IWUSR, acpi_root_dir,
 111                                        acpi_system_read_debug, (void *)1);
 112         if (entry)
 113                 entry->write_proc = acpi_system_write_debug;
 114         else
 115                 goto Error;
 116
 117  Done:
 118         return_VALUE(error);
 119
 120  Error:
 121         ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 122                          "Unable to create '%s' proc fs entry\n", name));
 123
 124         remove_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LEVEL, acpi_root_dir);
 125         remove_proc_entry(ACPI_SYSTEM_FILE_DEBUG_LAYER, acpi_root_dir);
 126         error = -EFAULT;
 127         goto Done;
 128 }
 129
 130 subsys_initcall(acpi_debug_init);