Hi Team,
Could you tell me how to modify the CPU frequency on RT SDK?
The SDK version I use is "Linux-RT Processor SDK for AM335x 08.02.00.24".
I would like to know the current frequency and how to modify it.
Here is the information on my board and there is no file named "scaling_cur_freq" .
root@am335x-evm:/sys/devices/system/cpu/cpu0# ls crash_notes of_node subsystem uevent crash_notes_size power topology
Could you tell me how to do it? Maybe tell me how to set dead-code frequency in driver?
Hi Bin,
Thanks for you sharing and please take a look on this question when you are available.
What I have done is to modify am33xx.dtsi and am335x-evmsk.dts on both u-boot and kernel stage.
But the vdd_mpu still is 1.35V, I am concerned that the frequency is not modified successfully.
Thanks.
arch/arm/boot/dts/am335x-evmsk.dts | 2 +-
arch/arm/boot/dts/am33xx.dtsi | 56 ------------------------------
2 files changed, 1 insertion(+), 57 deletions(-)
diff --git a/arch/arm/boot/dts/am335x-evmsk.dts b/arch/arm/boot/dts/am335x-evmsk.dts
index f5c893a13e0b..af2371cc9107 100644
--- a/arch/arm/boot/dts/am335x-evmsk.dts
+++ b/arch/arm/boot/dts/am335x-evmsk.dts
@@ -352,7 +352,7 @@
/* VDD_MPU voltage limits 0.95V - 1.26V with +/-4% tolerance */
regulator-name = "vdd_mpu";
regulator-min-microvolt = <912500>;
- regulator-max-microvolt = <1351500>;
+ regulator-max-microvolt = <1122000>;
regulator-boot-on;
regulator-always-on;
};
diff --git a/arch/arm/boot/dts/am33xx.dtsi b/arch/arm/boot/dts/am33xx.dtsi
index d29cb4ec3fd2..e80517e9a75f 100644
--- a/arch/arm/boot/dts/am33xx.dtsi
+++ b/arch/arm/boot/dts/am33xx.dtsi
@@ -83,68 +83,12 @@
* because the can not be enabled simultaneously on a
* single SoC.
*/
- opp50-300000000 {
- opp-hz = /bits/ 64 <300000000>;
- opp-microvolt = <950000 931000 969000>;
- opp-supported-hw = <0x06 0x0010>;
- opp-suspend;
- };
-
- opp100-275000000 {
- opp-hz = /bits/ 64 <275000000>;
- opp-microvolt = <1100000 1078000 1122000>;
- opp-supported-hw = <0x01 0x00FF>;
- opp-suspend;
- };
-
- opp100-300000000 {
- opp-hz = /bits/ 64 <300000000>;
- opp-microvolt = <1100000 1078000 1122000>;
- opp-supported-hw = <0x06 0x0020>;
- opp-suspend;
- };
-
- opp100-500000000 {
- opp-hz = /bits/ 64 <500000000>;
- opp-microvolt = <1100000 1078000 1122000>;
- opp-supported-hw = <0x01 0xFFFF>;
- };
opp100-600000000 {
opp-hz = /bits/ 64 <600000000>;
opp-microvolt = <1100000 1078000 1122000>;
opp-supported-hw = <0x06 0x0040>;
};
-
- opp120-600000000 {
- opp-hz = /bits/ 64 <600000000>;
- opp-microvolt = <1200000 1176000 1224000>;
- opp-supported-hw = <0x01 0xFFFF>;
- };
-
- opp120-720000000 {
- opp-hz = /bits/ 64 <720000000>;
- opp-microvolt = <1200000 1176000 1224000>;
- opp-supported-hw = <0x06 0x0080>;
- };
-
- oppturbo-720000000 {
- opp-hz = /bits/ 64 <720000000>;
- opp-microvolt = <1260000 1234800 1285200>;
- opp-supported-hw = <0x01 0xFFFF>;
- };
-
- oppturbo-800000000 {
- opp-hz = /bits/ 64 <800000000>;
- opp-microvolt = <1260000 1234800 1285200>;
- opp-supported-hw = <0x06 0x0100>;
- };
-
- oppnitro-1000000000 {
- opp-hz = /bits/ 64 <1000000000>;
- opp-microvolt = <1325000 1298500 1351500>;
- opp-supported-hw = <0x04 0x0200>;
- };
};
pmu@4b000000 {
--
2.17.1
Hi Bin:
This is the AM335 RT LINUX for CPU_Freq issue, customer Delta posted the below.
And I have read it, tested it.
The issue is clear:
Native Linux has the CPU Freq Scaling fine tune.
But the 8.2 RT Linux has no this function for allowing user to do that.
You can see the native Linux has this:
root@am335x-evm:~# echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_settspeed
root@am335x-evm:~# cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
I think, the fastest ways are:
Any comment?
BR Rio
