Add support for the early timer so we can use tracing with sandbox again.

Signed-off-by: Simon Glass <sjg@chromium.org>

A default invocation of sandbox U-Boot apparently uses no device tree,
which means that no timer is registers, which in turn means that the
sleep shell command hangs.

Fix the sandbox timer code to register a device when there's no DT, just
like e.g. the sandbox reset driver does. When there's no DT, the DM uclass
can't initialize clock_rate from DT, so set a default value in the
timer code instead.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

There are timers with a 64-bit counter value but current timer
uclass driver assumes a 32-bit one. Modify timer_get_count()
to ask timer driver to always return a 64-bit counter value,
and provide an inline helper function timer_conv_64() to handle
the 32-bit/64-bit conversion automatically.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

We should use device tree to pass the clock frequency of the timer
instead of hardcoded in the driver codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

Add a sandbox timer which get time from host os and a basic
test.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Simon Glass <sjg@chromium.org>