Hello Arthur Heymans, Matt DeVillier, Thomas Heijligen,
I'd like you to reexamine a change. Please visit
https://review.coreboot.org/c/libgfxinit/+/35717
to look at the new patch set (#2).
Change subject: gma hsw: Implement CDClk switching ......................................................................
gma hsw: Implement CDClk switching
For Haswell, we only read out the current CDClk setting and work with that (CDClk is supposed to be set only once per boot, so we leave that to the firmware). Broadwell supports actual frequency switching, with the following limits:
o a fuse may restrict us to 450MHz, o ULX supports at most 450MHz w/o additional cooling, o ULT supports at most 540MHz w/o additional cooling, o others support up to 675MHz.
We assume there is no `additional cooling`. With the CDClk now being switchable, we have to update `DP_Aux_Request` to assume the current CDClk frequency instead of the default.
Dot clocks, on these platforms, may run with full CDClk speed.
Change-Id: I8fb23a49b334f9f0045884c3af4087764397b941 Signed-off-by: Nico Huber nico.h@gmx.de --- M common/haswell_shared/hw-gfx-gma-power_and_clocks_haswell.adb M common/haswell_shared/hw-gfx-gma-power_and_clocks_haswell.ads M common/hw-gfx-gma-config.ads.template M common/hw-gfx-gma-dp_aux_request.adb M common/hw-gfx-gma-registers.ads M common/hw-gfx.ads 6 files changed, 184 insertions(+), 3 deletions(-)
git pull ssh://review.coreboot.org:29418/libgfxinit refs/changes/17/35717/2