cpufreq for rpi3
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Authored by jiashiun_gmail.com on Feb 16 2017, 7:35 PM.

Details

Reviewers

brd
gonzo

Commits

rS331897: MFC r314672, r315967, r324184, r325768
rS314672: [rpi] rpi3 should use the same cpufreq logic as rpi2, not rpi-b

Summary

RPi3 cpufreq is more like that on RPi2. Setting arm frequency above min (say, "sysctl hw.cpufreq.arm_freq=600000001") turns on turbo mode, and the firmware automatically raises voltage, sets frequency to max 1200MHz, and throttle when overheat, etc.

Swap if/else parts and use SOC_BCM2835 def so RPi3 can share the same cpufreq logic as RPi2, instead of falling to that for RPi.

Test Plan

Tested on RPi & RPi2 to make sure behavior was not changed.
Tested on RPi3 to get correct voltage report from verbose boot.

@@ -236,8 +236,8 @@
bcm2835_cpufreq0: Boot settings:
bcm2835_cpufreq0: current ARM 600MHz, Core 250MHz, SDRAM 400MHz, Turbo OFF
bcm2835_cpufreq0: max/min ARM 1200/600MHz, Core 400/250MHz, SDRAM 450/400MHz
-bcm2835_cpufreq0: current Core 30001200mV, SDRAM_C 30001200mV, SDRAM_I 30001200mV, SDRAM_P 30001200mV
-bcm2835_cpufreq0: max/min Core 32344950/30001200mV, SDRAM_C 30001200/30001200mV, SDRAM_I 30001200/30001200mV, SDRAM_P 30001200/30001200mV
+bcm2835_cpufreq0: current Core 1200mV, SDRAM_C 1200mV, SDRAM_I 1200mV, SDRAM_P 1200mV
+bcm2835_cpufreq0: max/min Core 1293/1200mV, SDRAM_C 1200/1200mV, SDRAM_I 1200/1200mV, SDRAM_P 1200/1200mV
bcm2835_cpufreq0: Temperature 51.5C
Release APs
mmc0: setting bus width to 4 bits