Hi,
I’d like to change the DMIC_HV voltages from 1.8v to 3.3v but am having difficulty getting this working.
I am using L4T32.2 but have been following the guide in the L4T28.2 documentation, section “TX2 Configuring Pinmux GPIO and PAD”, as I couldn’t find a similar section in the L4T32.2 documentation.
I have downloaded the L4T32.2 pinmux spreadsheet nv_Jetson-TX2-Series-Pinmux-Template and after changing the DMIC_HV voltage to 3.3v and generating a pad-default.dtsi file, I execute the pinmux-dts2cfg.py command to create a new padvoltage.cfg file.
Effectively file Linux_for_Tegra/bootloader/t186ref/BCT/tegra186-mb1-bct-pad-quill-p3310-1000-c03.cfg was modified from
##
## CFG version 1.0
## Input pad file name: tegra18x-p3310-1000-c0-cvm-config-padvoltage-default.dtsi
## Generation date: 2016-09-06 21:07
## PLEASE DO NOT EDIT THIS FILE
## This is autogenerated file using the script pinmux-dts2cfg.py
##
# AUDIO_HV : 1.8V
# DMIC_HV : 1.8V
# SDMMC1_HV : 3.3V
# SDMMC2_HV : 3.3V
# SDMMC3_HV : 3.3V
# AO_HV : 3.3V
# SPI : 1.8V
# DBG : 1.8V
# UFS : 1.8V
pmc.major = 1;
pmc.minor = 0;
pmc.0x0c36003c = 0x0000003e; # PMC_IMPL_E_18V_PWR_0
pmc.0x0c360040 = 0x00000079; # PMC_IMPL_E_33V_PWR_0
to
##
## CFG version 1.0
## Input pad file name: tegra18x-p3310-1000-c0-cvm-config-padvoltage-default.dtsi
## Generation date: 2019-11-22 11:08
## PLEASE DO NOT EDIT THIS FILE
## This is autogenerated file using the script pinmux-dts2cfg.py
##
# AUDIO_HV : 1.8V
# DMIC_HV : 3.3V
# SDMMC1_HV : 3.3V
# SDMMC2_HV : 3.3V
# SDMMC3_HV : 3.3V
# AO_HV : 3.3V
# SPI : 1.8V
# DBG : 1.8V
# UFS : 1.8V
pmc.major = 1;
pmc.minor = 0;
pmc.0x0c36003c = 0x0000003e; # PMC_IMPL_E_18V_PWR_0
pmc.0x0c360040 = 0x0000007d; # PMC_IMPL_E_33V_PWR_0
After re-flashing the bootloader, and enabling one of the GPIOs in the block as follows
sudo su
echo 390 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio390/direction
echo 1 > /sys/class/gpio/gpio390/value
The voltage of pin GPIO18_MDM_COLDBOOT(GPIO3_PI.06) still measured 1.8v. I can confirm that this is the correct pin because after executing “echo 0 > /sys/class/gpio/gpio390/value”, the pin reports 0v.
Is there something else I am missing?
Do I need to re-flash the file-system for the new cfg file to take effect?
Is there a way I can observe the applied pad voltage settings on the TX2?
Thanks.