#include <fcntl.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include "debug.h"
#include "sysfs.h"

#define DIR_BUF_SIZE 1024

// Validate if we found a file named cpu[0-9][0-9
int cpufreq_is_cpu(char *name)
{
 if (strncmp(name,"cpu",3)!=0) return 0;
 if ((name[3]<'0') || (name[3]>'9')) return 0;
 if (name[4]==0) return 1;

 if ((name[4]<'0') || (name[4]>'9')) return 0;
 if (name[5]==0) return 1;

 return 0;
}

// Set a cpufreq parameter to a value
int cpufreq_set_str(char *parameter,char *value,long int checkdelay)
{
 int fd;
 char sysfs_file[128];
 int done=0;

 DEBUG1_CPUFREQ("Set %s to %s\n",parameter,value)

 char buf[DIR_BUF_SIZE];
 long nread;

 struct linux_dirent {
  unsigned long d_ino;
  off_t d_off;
  unsigned short d_reclen;
  char d_name[];
 };

 struct linux_dirent *d;
 size_t bpos;

// Open the CPU directory in sysfs
 fd=open("/sys/devices/system/cpu",O_RDONLY|O_DIRECTORY);
 if (fd==-1)
 {
  DEBUG1_CPUFREQ("Unable to find CPU's\n");
  return -1;
 }

 while(1)
 {
// Iterate over SYS_getdents calls
  nread=syscall(SYS_getdents,fd,buf,DIR_BUF_SIZE);

// If we can't read return an error
  if (nread==-1)
  {
   DEBUG1_CPUFREQ("Unable to find CPU's\n");
   close(fd);
   return -1;
  }

// If there are no entries left we're done
  if (nread==0) break;

// Iterate over returned file info
  for(bpos=0;bpos<nread;)
  {
   d=(struct linux_dirent *)(buf+bpos);

// If it's a CPU, set our parameter
   if (cpufreq_is_cpu(d->d_name))
   {
    DEBUG2_CPUFREQ("Found CPU %s\n",d->d_name);
    snprintf(sysfs_file,128,"/sys/devices/system/cpu/%s/cpufreq/%s",d->d_name,parameter);
    if (sysfs_write_str(sysfs_file,value,checkdelay)!=0)
    {
     DEBUG1_CPUFREQ("Failed to set %s\n",d->d_name);
     return -1;
    }
    done++;
   }
   bpos+=d->d_reclen;
  } 
 }
 close(fd);

 return done;
}

// This is just a wrapper around cpufreq_set_str with long int to string
// convertion
int cpufreq_set_long_int(char *parameter,long int value,long int checkdelay)
{
 char buf[255];

 snprintf(buf,255,"%ld",value);
 return cpufreq_set_str(parameter,buf,checkdelay);
}