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// SPDX-License-Identifier: GPL-2.0-only
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "cpupower_intern.h"
#include "acpi_cppc.h"
/* ACPI CPPC sysfs access ***********************************************/
static int acpi_cppc_read_file(unsigned int cpu, const char *fname,
char *buf, size_t buflen)
{
char path[SYSFS_PATH_MAX];
snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/acpi_cppc/%s",
cpu, fname);
return cpupower_read_sysfs(path, buf, buflen);
}
static const char * const acpi_cppc_value_files[] = {
[HIGHEST_PERF] = "highest_perf",
[LOWEST_PERF] = "lowest_perf",
[NOMINAL_PERF] = "nominal_perf",
[LOWEST_NONLINEAR_PERF] = "lowest_nonlinear_perf",
[LOWEST_FREQ] = "lowest_freq",
[NOMINAL_FREQ] = "nominal_freq",
[REFERENCE_PERF] = "reference_perf",
[WRAPAROUND_TIME] = "wraparound_time"
};
unsigned long acpi_cppc_get_data(unsigned int cpu, enum acpi_cppc_value which)
{
unsigned long long value;
unsigned int len;
char linebuf[MAX_LINE_LEN];
char *endp;
if (which >= MAX_CPPC_VALUE_FILES)
return 0;
len = acpi_cppc_read_file(cpu, acpi_cppc_value_files[which],
linebuf, sizeof(linebuf));
if (len == 0)
return 0;
value = strtoull(linebuf, &endp, 0);
if (endp == linebuf || errno == ERANGE)
return 0;
return value;
}
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