soc/tegra: pmc: Support systems where PMC is marked secure
authorMikko Perttunen <mperttunen@nvidia.com>
Fri, 25 Jan 2019 10:22:55 +0000 (11:22 +0100)
committerThierry Reding <treding@nvidia.com>
Fri, 25 Jan 2019 15:18:24 +0000 (16:18 +0100)
commite247deae1a55089cb04cc25c91faeba083d0c39c
tree2c85583a47f879f93b7751e54fe668fbfb528a31
parentfa3bc04ef8ccccfe47db1f4030a7a43569956402
soc/tegra: pmc: Support systems where PMC is marked secure

On Tegra210 systems with new enough boot software, direct register
accesses to PMC register space from the non-secure world are not
allowed. Instead a monitor call may be used to read and write PMC
registers.

Add code to detect such a system by attempting to write a scratch
register and detecting if the write happened or not. If not, we switch
to doing all register accesses through the monitor call.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
drivers/soc/tegra/pmc.c