CPU
Contents
1 S5P4418/S5P6818
1.1 Setting CPU's Max Clock
1.1.1 Method 1
The following command is used to temporarily limit the maximum CPU frequency to 1GHz: echo 1000000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
1.1.2 Method 2
Modify the kernel source code:
arch/arm/plat-s5p4418/nanopi2/device.c
Delete the unwanted frequencies in the following array:
static unsigned long dfs_freq_table[][2] = {
{ 1400000, 1200000, },
{ 1200000, 1120000, },
{ 1000000, 1040000, },
{ 800000, 1000000, },
{ 700000, 940000, },
{ 600000, 940000, },
{ 500000, 940000, },
{ 400000, 940000, },
};1.2 CPU thermal
Get CPU's working temperature by reading the following files:
S5P4418/S5P6818:
/sys/class/hwmon/hwmon0/device/temp_label
Allwinner H3/H5/A64:
/sys/class/thermal/thermal_zone0/temp
RK3399, get CPU's working temperature and clock:
while true; do t1=`cat /sys/class/thermal/thermal_zone0/temp` t2=`cat /sys/class/thermal/thermal_zone1/temp` f1=`cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq` f2=`cat /sys/devices/system/cpu/cpu4/cpufreq/cpuinfo_cur_freq` echo "$t1 $t2 $f1 $f2" sleep 1 #cat /sys/class/thermal/thermal_zone[01]/temp #cat /sys/devices/system/cpu/cpu[04]/cpufreq/cpuinfo_cur_freq done
2 H3
2.1 CPU DVFS
2.1.1 Linux-4.14
All H3 based boards have the same DVFS setting and the setting is in the "arch/arm/boot/dts/sun8i-h3-nanopi.dtsi" file:
&cpu0 {
operating-points = <
1008000 1300000
816000 1100000
624000 1100000
480000 1100000
312000 1100000
240000 1100000
120000 1100000
>;
#cooling-cells = <2>;
cooling-min-level = <0>;
cooling-max-level = <6>;
cpu0-supply = <&vdd_cpux>;
};
&cpu_thermal {
trips {
cpu_warm: cpu_warm {
temperature = <65000>;
hysteresis = <2000>;
type = "passive";
};
cpu_hot: cpu_hot {
temperature = <75000>;
hysteresis = <2000>;
type = "passive";
};
cpu_very_hot: cpu_very_hot {
temperature = <90000>;
hysteresis = <2000>;
type = "passive";
};
cpu_crit: cpu_crit {
temperature = <105000>;
hysteresis = <2000>;
type = "critical";
};
};
cooling-maps {
cpu_warm_limit_cpu {
trip = <&cpu_warm>;
cooling-device = <&cpu0 THERMAL_NO_LIMIT 1>;
};
cpu_hot_limit_cpu {
trip = <&cpu_hot>;
cooling-device = <&cpu0 2 3>;
};
cpu_very_hot_limit_cpu {
trip = <&cpu_very_hot>;
cooling-device = <&cpu0 5 THERMAL_NO_LIMIT>;
};
};
};2.2 CPU ID
2.2.1 Linux-4.14
As for Allwinner H2+/H3/H5/ SoCs each of these CPUs has an internal 16-btye CHIP ID which can be read by running the following commands in the Linux-4.14 kernel:
$ apt-get install bsdmainutils $ hexdump /sys/bus/nvmem/devices/sunxi-sid0/nvmem 0000000 8082 0447 0064 04c3 3650 ce0a 1e28 2202 0000010 0002 0000 0000 0000 0000 0000 0000 0000 0000020 0000 0000 0000 0000 0000 0000 0000 0000 0000030 0000 0008 0508 0000 0000 0000 0000 0000 0000040 0000 0000 0000 0000 0000 0000 0000 0000
"8082 0447 0064 04c3 3650 ce0a 1e28 2202" is the 16-byte CHIP ID.
2.3 CPU thermal
2.3.1 Linux-4.14
$ cat /sys/class/thermal/thermal_zone0/temp 30489
The reading means the working temperature is 30.489 degrees Celsius.
3 H5
3.1 CPU DVFS
3.1.1 Linux-4.14
For H5 based boards different boards have different DVFS settings. Let's take the NanoPi NEO2 as an example the setting is in the "arch/arm64/boot/dts/allwinner/sun50i-h5-nanopi-neo2.dts" file:
&cpu0 {
operating-points = <
1008000 1100000
816000 1100000
624000 1100000
480000 1100000
312000 1100000
240000 1100000
120000 1100000
>;
#cooling-cells = <2>;
cooling-min-level = <0>;
cooling-max-level = <6>;
cpu0-supply = <&vdd_cpux>;
};
&cpu_thermal {
trips {
cpu_warm: cpu_warm {
temperature = <65000>;
hysteresis = <2000>;
type = "passive";
};
cpu_hot: cpu_hot {
temperature = <75000>;
hysteresis = <2000>;
type = "passive";
};
cpu_very_hot: cpu_very_hot {
temperature = <90000>;
hysteresis = <2000>;
type = "passive";
};
cpu_crit: cpu_crit {
temperature = <105000>;
hysteresis = <2000>;
type = "critical";
};
};
cooling-maps {
cpu_warm_limit_cpu {
trip = <&cpu_warm>;
cooling-device = <&cpu0 THERMAL_NO_LIMIT 1>;
};
cpu_hot_limit_cpu {
trip = <&cpu_hot>;
cooling-device = <&cpu0 2 3>;
};
cpu_very_hot_limit_cpu {
trip = <&cpu_very_hot>;
cooling-device = <&cpu0 5 THERMAL_NO_LIMIT>;
};
};
};3.2 CPU ID
3.2.1 Linux-4.14
As for Allwinner H2+/H3/H5/ SoCs each of these CPUs has an internal 16-btye CHIP ID which can be read by running the following commands in the Linux-4.14 kernel:
$ apt-get install bsdmainutils $ hexdump /sys/bus/nvmem/devices/sunxi-sid0/nvmem 0000000 8082 0447 0064 04c3 3650 ce0a 1e28 2202 0000010 0002 0000 0000 0000 0000 0000 0000 0000 0000020 0000 0000 0000 0000 0000 0000 0000 0000 0000030 0000 0008 0508 0000 0000 0000 0000 0000 0000040 0000 0000 0000 0000 0000 0000 0000 0000
"8082 0447 0064 04c3 3650 ce0a 1e28 2202" is the 16-byte CHIP ID.
3.3 CPU thermal
3.3.1 Linux-4.14
$ cat /sys/class/thermal/thermal_zone0/temp 30489
The reading means the working temperature is 30.489 degrees Celsius.
