From 15d9095122c0d4f9a4dab05fb0e84d84c624e1b4 Mon Sep 17 00:00:00 2001
From: PA4WDH
Date: Sat, 20 May 2023 17:17:43 +0200
Subject: Translate POC to C code

---
 cpufreq.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 cpufreq.c

(limited to 'cpufreq.c')

diff --git a/cpufreq.c b/cpufreq.c
new file mode 100644
index 0000000..d9e0e4e
--- /dev/null
+++ b/cpufreq.c
@@ -0,0 +1,82 @@
+#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
+
+int cpufreq_is_cpu(char *name)
+{
+ if (strncmp(name,"cpu",3)!=0) return 0;
+ if ((name[3]<'0') || (name[3]>'9')) return 0;
+
+ return 1;
+}
+
+int cpufreq_set_str(char *parameter,char *value,int checkdelay)
+{
+ int fd;
+ char sysfs_file[128];
+
+ 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;
+
+ 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)
+ {
+  nread=syscall(SYS_getdents,fd,buf,DIR_BUF_SIZE);
+  if (nread==-1)
+  {
+   DEBUG1_CPUFREQ("Unable to find CPU's\n");
+   close(fd);
+   return -1;
+  }
+  if (nread==0) break;
+
+  for(bpos=0;bpos<nread;)
+  {
+   d=(struct linux_dirent *)(buf+bpos);
+   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;
+    }
+   }
+   bpos+=d->d_reclen;
+  } 
+ }
+ close(fd);
+}
+
+int cpufreq_set_long_int(char *parameter,long int value,int checkdelay)
+{
+ char buf[255];
+
+ snprintf(buf,255,"%ld",value);
+ cpufreq_set_str(parameter,buf,checkdelay);
+}
-- 
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