This driver exposes EMC frequency control interface to user space via
linux devfreq framework.
Users could change EMC frequency to the frequency value from the
available frequencies of EMC clock:
$ /sys/class/devfreq/bwmgr# cat available_frequencies
665600000 2750000000 3200000000 4266000000
and update the EMC floor frequency by writing into the min_freq QoS
sysfs node:
$ /sys/class/devfreq/bwmgr# echo 4266000000 > min_freq
and update the EMC max frequency by writing into the max_rate QoS
sysfs node to cap the EMC frequency:
$ /sys/class/devfreq/bwmgr# echo 4266000000 > max_freq
This driver does not directly manage the EMC clock rate. Instead it
just delivers the min/max frequency information to BPMP, and BPMP is
still the only entity that has the full control of EMC and other
related memory clocks.
Bug 5483386
Bug 5196455
Change-Id: I6124eeb7411a13bde5c51582064534063abca8d3
Signed-off-by: Johnny Liu <johnliu@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nv-oot/+/3453755
GVS: buildbot_gerritrpt <buildbot_gerritrpt@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: Rajkumar Kasirajan <rkasirajan@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
