CPU

查看中文

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 code 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

表示当前CPU温度为30.489摄氏度。

3 H5

3.1 CPU DVFS

3.1.1 Linux-4.14

对于H5系列的开发板，不同型号的DVFS设置是不一样的。 以NanoPi NEO2为例，相关代码位于arch/arm64/boot/dts/allwinner/sun50i-h5-nanopi-neo2.dts:

&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

表示当前CPU温度为30.489摄氏度。