• Martin Blumenstingl's avatar
    ARM: dts: meson8b: fix the operating voltage of the Mali GPU · 26d65140
    Martin Blumenstingl authored
    Amlogic's vendor kernel defines an OPP for the GPU on Meson8b boards
    with a voltage of 1.15V. It turns out that the vendor kernel relies on
    the bootloader to set up the voltage. The bootloader however sets a
    fixed voltage of 1.10V.
    
    Amlogic's patched u-boot sources (uboot-2015-01-15-23a3562521) confirm
    this:
    $ grep -oiE "VDD(EE|AO)_VOLTAGE[ ]+[0-9]+" board/amlogic/configs/m8b_*
      board/amlogic/configs/m8b_m100_v1.h:VDDAO_VOLTAGE            1100
      board/amlogic/configs/m8b_m101_v1.h:VDDAO_VOLTAGE            1100
      board/amlogic/configs/m8b_m102_v1.h:VDDAO_VOLTAGE            1100
      board/amlogic/configs/m8b_m200_v1.h:VDDAO_VOLTAGE            1100
      board/amlogic/configs/m8b_m201_v1.h:VDDEE_VOLTAGE            1100
      board/amlogic/configs/m8b_m201_v1.h:VDDEE_VOLTAGE            1100
      board/amlogic/configs/m8b_m202_v1.h:VDDEE_VOLTAGE            1100
    
    Another hint at this is the VDDEE voltage on the EC-100 and Odroid-C1
    boards. The VDDEE regulator supplies the Mali GPU. It's basically a copy
    of the VCCK (CPU supply) which means it's limited to 0.86V to 1.14V.
    
    Update the operating voltage of the Mali GPU on Meson8b to 1.10V so it
    matches with what the vendor u-boot sets.
    
    Fixes: c3ea80b6 ("ARM: dts: meson8b: add the Mali-450 MP2 GPU")
    Signed-off-by: default avatarMartin Blumenstingl <martin.blumenstingl@googlemail.com>
    Signed-off-by: default avatarKevin Hilman <khilman@baylibre.com>
    26d65140
meson8b.dtsi 13.5 KB