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>

Every timer device needs to have a valid clock frequency and it
can be specified in the device tree. Use pre_probe() to get this
in the timer uclass driver.

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

This changes 'Timer' to 'timer' at several places.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Simon Glass <sjg@chromium.org>

Implement a Timer uclass to work with lib/time.c.

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