dr,gpu以及arm的clock都受dvfs模塊管控, 所以只要執行:
root@rk3288:/ # cat /sys/dvfs/dvfs_tree
[78603.186480] -------------DVFS TREE-----------
[78603.186548] DVFS TREE:
[78603.186569] |- voltage domain:vd_gpu
[78603.186598] |- current voltage:950000
[78603.186617] |- current regu_mode:UNKNOWN
[78603.186640] | |- power domain:pd_gpu, status = OFF, current volt = 950000, current regu_mode = UNKNOWN
[78603.186677] | | |- clock: clk_gpu current: rate 198000, volt = 950000, enable_dvfs = ENABLE
[78603.186714] | | |- clk limit(enable):[198000000, 480000000]; last set rate = 198000
[78603.186737] | | | |- freq = 198000, volt = 950000
[78603.186756] | | | |- freq = 297000, volt = 950000
[78603.186776] | | | |- freq = 417000, volt = 1100000
[78603.186795] | | | |- freq = 480000, volt = 1150000
[78603.186818] | | |- clock: clk_gpu current: rate 198000, regu_mode = UNKNOWN, regu_mode_en = 0
[78603.186840] |
[78603.186840] |- voltage domain:vd_logic
[78603.186867] |- current voltage:1150000
[78603.186885] |- current regu_mode:UNKNOWN
[78603.186906] | |- power domain:pd_vio, status = OFF, current volt = 1150000, current regu_mode = UNKNOWN
[78603.186943] | | |- clock: aclk_vio1 current: rate 325000, volt = 1150000, enable_dvfs = ENABLE
[78603.186979] | | |- clk limit(enable):[82000000, 325000000]; last set rate = 325000
[78603.187001] | | | |- freq = 82000, volt = 1150000
[78603.187021] | | | |- freq = 325000, volt = 1150000
[78603.187044] | | |- clock: aclk_vio1 current: rate 325000, regu_mode = UNKNOWN, regu_mode_en = 0
[78603.187070] | |- power domain:pd_ddr, status = OFF, current volt = 1150000, current regu_mode = UNKNOWN
[78603.187106] | | |- clock: clk_ddr current: rate 396000, volt = 1150000, enable_dvfs = ENABLE
[78603.187141] | | |- clk limit(enable):[200000000, 528000000]; last set rate = 396000
[78603.187163] | | | |- freq = 200000, volt = 1150000
[78603.187182] | | | |- freq = 300000, volt = 1150000
[78603.187202] | | | |- freq = 396000, volt = 1150000
[78603.187221] | | | |- freq = 528000, volt = 1150000
[78603.187243] | | |- clock: clk_ddr current: rate 396000, regu_mode = UNKNOWN, regu_mode_en = 0
[78603.187265] |
[78603.187265] |- voltage domain:vd_arm
[78603.187292] |- current voltage:900000
[78603.187310] |- current regu_mode:UNKNOWN
[78603.187331] | |- power domain:pd_core, status = OFF, current volt = 900000, current regu_mode = UNKNOWN
[78603.187367] | | |- clock: clk_core current: rate 408000, volt = 900000, enable_dvfs = ENABLE
[78603.187402] | | |- clk limit(enable):[408000000, 1608000000]; last set rate = 408000
[78603.187424] | | | |- freq = 408000, volt = 900000
[78603.187443] | | | |- freq = 600000, volt = 950000
[78603.187462] | | | |- freq = 816000, volt = 1000000
[78603.187482] | | | |- freq = 1008000, volt = 1050000
[78603.187501] | | | |- freq = 1200000, volt = 1100000
[78603.187521] | | | |- freq = 1416000, volt = 1200000
[78603.187540] | | | |- freq = 1608000, volt = 1350000
[78603.187563] | | |- clock: clk_core current: rate 408000, regu_mode = UNKNOWN, regu_mode_en = 0
[78603.187585] -------------DVFS TREE END------------
在rk3288.dtsi中,有:
temp-limit-enable = <1>;
target-temp = <80>;
min_temp_limit = <312000>;
normal-temp-limit = <
/* delta-temp delta-freq */
3 96000
6 144000
9 192000
15 384000
>;
第一列爲降低每一級閥值,第二列爲降低頻率,默認溫控開始溫度是80°.
例如當前溫度是82°,那麼不作用,當達到83°時, 溫控降頻開始有效,假設系統當前要設置1008000KHz,
那麼經過溫控系統之後會減去96000KHz. 如果溫度很高,就會一直這樣減下去,減到不能低於min_temp_limit爲止.
root@rk3288:/ # cat /sys/bus/cpu/devices/cpu0/cpufreq/cpuinfo_cur_freq
408000
root@rk3288:/ # cat /sys/devices/ff280000.tsadc/temp1_input
41
governor：
root@rk3288:/ # ls -l /sys/bus/cpu/devices/cpu0/cpufreq/
-r--r--r-- root root 4096 2018-04-16 17:08 affected_cpus
-r-------- root root 4096 2018-04-16 17:08 cpuinfo_cur_freq
-r--r--r-- root root 4096 2018-04-16 17:08 cpuinfo_max_freq
-r--r--r-- root root 4096 2018-04-16 17:08 cpuinfo_min_freq
-r--r--r-- root root 4096 2018-04-16 17:08 cpuinfo_transition_latency
-r--r--r-- root root 4096 2018-04-16 17:08 related_cpus
-r--r--r-- root root 4096 2018-04-16 17:08 scaling_available_frequencies
-r--r--r-- root root 4096 2018-04-16 17:08 scaling_available_governors
-r--r--r-- root root 4096 2018-04-16 17:08 scaling_cur_freq
-r--r--r-- root root 4096 2018-04-16 17:08 scaling_driver
-rw-rw-r-- system system 4096 2018-04-16 17:08 scaling_governor
-rw-rw---- system system 4096 2018-04-16 17:08 scaling_max_freq
-rw-rw---- system system 4096 2018-04-16 17:08 scaling_min_freq
-rw-rw-r-- system system 4096 2018-04-16 17:08 scaling_setspeed
drwxr-xr-x root root 2018-04-16 17:08 stats
GPU的DVFS不是在dts而是在驅動中直接控制並且默認打開的
root@rk3288:/ # echo on > /sys/devices/ffa30000.gpu/dvfs
root@rk3288:/ # echo off > /sys/devices/ffa30000.gpu/dvfs