1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | |
3 | #include <stdio.h> |
4 | #include <errno.h> |
5 | #include <stdlib.h> |
6 | #include <string.h> |
7 | #include <sys/types.h> |
8 | #include <sys/stat.h> |
9 | #include <fcntl.h> |
10 | #include <unistd.h> |
11 | |
12 | #include "cpupower_intern.h" |
13 | #include "acpi_cppc.h" |
14 | |
15 | /* ACPI CPPC sysfs access ***********************************************/ |
16 | |
17 | static int acpi_cppc_read_file(unsigned int cpu, const char *fname, |
18 | char *buf, size_t buflen) |
19 | { |
20 | char path[SYSFS_PATH_MAX]; |
21 | |
22 | snprintf(path, sizeof(path), PATH_TO_CPU "cpu%u/acpi_cppc/%s" , |
23 | cpu, fname); |
24 | return cpupower_read_sysfs(path, buf, buflen); |
25 | } |
26 | |
27 | static const char * const acpi_cppc_value_files[] = { |
28 | [HIGHEST_PERF] = "highest_perf" , |
29 | [LOWEST_PERF] = "lowest_perf" , |
30 | [NOMINAL_PERF] = "nominal_perf" , |
31 | [LOWEST_NONLINEAR_PERF] = "lowest_nonlinear_perf" , |
32 | [LOWEST_FREQ] = "lowest_freq" , |
33 | [NOMINAL_FREQ] = "nominal_freq" , |
34 | [REFERENCE_PERF] = "reference_perf" , |
35 | [WRAPAROUND_TIME] = "wraparound_time" |
36 | }; |
37 | |
38 | unsigned long acpi_cppc_get_data(unsigned int cpu, enum acpi_cppc_value which) |
39 | { |
40 | unsigned long long value; |
41 | unsigned int len; |
42 | char linebuf[MAX_LINE_LEN]; |
43 | char *endp; |
44 | |
45 | if (which >= MAX_CPPC_VALUE_FILES) |
46 | return 0; |
47 | |
48 | len = acpi_cppc_read_file(cpu, acpi_cppc_value_files[which], |
49 | linebuf, sizeof(linebuf)); |
50 | if (len == 0) |
51 | return 0; |
52 | |
53 | value = strtoull(linebuf, &endp, 0); |
54 | |
55 | if (endp == linebuf || errno == ERANGE) |
56 | return 0; |
57 | |
58 | return value; |
59 | } |
60 | |