A subsequent patch will enable the use of the architected timer on
ARMv8. Doing so implies that udelay() will be backed by this timer
implementation, and hence the architected timer must be ready when
udelay() is first called. The first time udelay() is used is while
resetting the debug UART, which happens very early. Make sure that
arch_timer_init() is called before that.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
A harmless but confusing warning is displayed when looking up the
DisplayPort PLL. Correct this.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Add functions to provide access to the display clocks on Tegra124 including
setting the clock rate for an EDP display.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Create a function which sets the source clock for a peripheral, given
the number of mux bits to adjust. This can then be used more generally.
For now, don't export it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
The get_pll() function can do the wrong thing if passed values that are
out of range. Add checks for this and add a function which can return
a 'simple' PLL. This can be defined by SoCs with their own clocks.
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
When the CPU is in non-secure (NS) mode (when running U-Boot under a
secure monitor), certain actions cannot be taken, since they would need
to write to secure-only registers. One example is configuring the ARM
architectural timer's CNTFRQ register.
We could support this in one of two ways:
1) Compile twice, once for secure mode (in which case anything goes) and
once for non-secure mode (in which case certain actions are disabled).
This complicates things, since everyone needs to keep track of
different U-Boot binaries for different situations.
2) Detect NS mode at run-time, and optionally skip any impossible actions.
This has the advantage of a single U-Boot binary working in all cases.
(2) is not possible on ARM in general, since there's no architectural way
to detect secure-vs-non-secure. However, there is a Tegra-specific way to
detect this.
This patches uses that feature to detect secure vs. NS mode on Tegra, and
uses that to:
* Skip the ARM arch timer initialization.
* Set/clear an environment variable so that boot scripts can take
different action depending on which mode the CPU is in. This might be
something like:
if CPU is secure:
load secure monitor code into RAM.
boot secure monitor.
secure monitor will restart (a new copy of) U-Boot in NS mode.
else:
execute normal boot process
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
