From a312ca1c5002f70c7e8cf9fcb802bbf7689dfca2 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Udo=20Schl=C3=A4pfer?= Date: Wed, 21 Jan 2015 20:35:03 +0100 Subject: [PATCH] CPUFreq scaling governor interface for Linux/Android hosted devices. For a usage example see http://gerrit.rockbox.org/r/#/c/1074/ Change-Id: I1d61e0eba6552a9b5d6e15a2e3169435b2f7079d --- firmware/SOURCES | 1 + firmware/target/hosted/cpufreq-linux.c | 151 +++++++++++++++++++++++++ firmware/target/hosted/cpufreq-linux.h | 58 ++++++++++ 3 files changed, 210 insertions(+) create mode 100644 firmware/target/hosted/cpufreq-linux.c create mode 100644 firmware/target/hosted/cpufreq-linux.h diff --git a/firmware/SOURCES b/firmware/SOURCES index cf8a59bd00..999d92012c 100644 --- a/firmware/SOURCES +++ b/firmware/SOURCES @@ -12,6 +12,7 @@ powermgmt.c #ifdef __linux__ target/hosted/cpuinfo-linux.c +target/hosted/cpufreq-linux.c #endif #if !defined(SAMSUNG_YPR0) || defined(SIMULATOR) /* uses as3514 rtc */ diff --git a/firmware/target/hosted/cpufreq-linux.c b/firmware/target/hosted/cpufreq-linux.c new file mode 100644 index 0000000000..55a0bf3292 --- /dev/null +++ b/firmware/target/hosted/cpufreq-linux.c @@ -0,0 +1,151 @@ +/*************************************************************************** + * __________ __ ___ + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * + * Copyright (C) 2015 by Udo Schläpfer + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + ****************************************************************************/ + + +#include +#include + +#include "config.h" +#include "cpuinfo-linux.h" +#include "debug.h" + +#include "cpufreq-linux.h" + + +static FILE* open_read(const char* file_name) +{ + FILE *f = fopen(file_name, "r"); + if(f == NULL) + { + DEBUGF("ERROR %s: Can not open %s for reading.", __func__, file_name); + } + + return f; +} + + +void cpufreq_available_governors(char* governors, int governors_size, int cpu) +{ + if(governors_size <= 0) + { + DEBUGF("ERROR %s: Invalid governors_size: %d.", __func__, governors_size); + return; + } + + if(cpu < 0) + { + DEBUGF("ERROR %s: Invalid cpu: %d.", __func__, cpu); + return; + } + + char available_governors_interface[70]; + + snprintf(available_governors_interface, + sizeof(available_governors_interface), + "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_available_governors", + cpu); + + FILE *f = open_read(available_governors_interface); + if(f == NULL) + { + return; + } + + if(fgets(governors, governors_size, f) == NULL) + { + DEBUGF("ERROR %s: Read failed for %s.", __func__, available_governors_interface); + fclose(f); + return; + } + + DEBUGF("DEBUG %s: Available governors for cpu %d: %s.", __func__, cpu, governors); + + fclose(f); +} + + +static FILE* open_write(const char* file_name) +{ + FILE *f = fopen(file_name, "w"); + if(f == NULL) + { + DEBUGF("ERROR %s: Can not open %s for writing.", __func__, file_name); + } + + return f; +} + + +static void set_governor_for_cpu(const char* governor, int cpu) +{ + DEBUGF("DEBUG %s: governor: %s, cpu: %d.", __func__, governor, cpu); + + char scaling_governor_interface[64]; + + snprintf(scaling_governor_interface, + sizeof(scaling_governor_interface), + "/sys/devices/system/cpu/cpu%d/cpufreq/scaling_governor", + cpu); + + FILE *f = open_write(scaling_governor_interface); + if(f == NULL) + { + return; + } + + if(fprintf(f, "%s", governor) < 1) + { + DEBUGF("ERROR %s: Write failed for %s.", __func__, scaling_governor_interface); + } + + fclose(f); +} + + +void cpufreq_set_governor(const char* governor, int cpu) +{ + if(governor == NULL) + { + DEBUGF("ERROR %s: Invalid governor.", __func__); + return; + } + + if(cpu < CPUFREQ_ALL_CPUS) + { + DEBUGF("ERROR %s: Invalid cpu: %d.", __func__, cpu); + return; + } + + DEBUGF("DEBUG %s: governor: %s, cpu: %d.", __func__, governor, cpu); + + if(cpu == CPUFREQ_ALL_CPUS) + { + int max_cpu = cpucount_linux(); + + for(int count = 0; count < max_cpu; ++count) + { + set_governor_for_cpu(governor, count); + } + } + else + { + set_governor_for_cpu(governor, cpu); + } +} diff --git a/firmware/target/hosted/cpufreq-linux.h b/firmware/target/hosted/cpufreq-linux.h new file mode 100644 index 0000000000..f62e0225dd --- /dev/null +++ b/firmware/target/hosted/cpufreq-linux.h @@ -0,0 +1,58 @@ +/*************************************************************************** + * __________ __ ___ + * Open \______ \ ____ ____ | | _\_ |__ _______ ___ + * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / + * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < + * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ + * \/ \/ \/ \/ \/ + * + * Copyright (C) 2015 by Udo Schläpfer + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY + * KIND, either express or implied. + * + * + * Interface for the Linux CPUFreq kernel modul. + * See https://www.kernel.org/doc/Documentation/cpu-freq/ + * + ****************************************************************************/ + + +#ifndef __CPUFREQ_LINUX_H__ +#define __CPUFREQ_LINUX_H__ + + +#include + + +/* + Get the available governors for cpu. + governors Preallocated string for the available governors. On succes this will look like + "performance ondemand powersave", each word beeing a governor that can be used with + cpufreq_set_governor. + governors_size Size of governors. + cpu The cpu, starting with 0, for which to get the available governors. CPUFREQ_ALL_CPUS is not + supported, you must supply a cpu. See cpucount_linux in cpuinfo-linux.h. +*/ +void cpufreq_available_governors(char* governors, int governors_size, int cpu); + + +/* + Set the cpufreq governor for cpu. + governor The governor to set. This must be one of the available governors returned by + cpufreq_available_governors. + cpu The cpu, starting with 0, for which to set the governor. CPUFREQ_ALL_CPUS to set + the governor for all cpus. See cpucount_linux in cpuinfo-linux.h. +*/ +void cpufreq_set_governor(const char* governor, int cpu); + + +static const int CPUFREQ_ALL_CPUS = -1; + + +#endif