Adjusts the minimum memory frequency when the cpu frequency
changes.  The values are currently hardcoded to a reasonable
default.  If memory frequency scaling is not enabled this
patch will have no effect.
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NColin Cross <ccross@android.com>

During cpu frequency changes, take an extra reference to pllx so
that it doesn't turn off and on while the cpu is temporarily on
pllp.  If the cpu is moved to pllp permanently, pllx will be
turned off.
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NColin Cross <ccross@android.com>

The existing version did not extend well to core dvfs, drop it
for now until the new clk api with clk_prepare and clk_unprepare
is ready and non-atomic clocks are possible.
Acked-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NColin Cross <ccross@android.com>

On Tegra, calling clk_set_rate on the CPU clock may call into the
regulator API.  If the regulator driver that controls the CPU
voltage rail has been suspended, this can lead to attempted
communication with a hardware block that has already been turned
off.

Adds a SUSPEND_PREPARE notification hook to drop the frequency to
the lowest possible during suspend.

Also adds 216MHz (off of PLLP) as the lowest CPU frequency, which
allows PLLX to be turned off.
Signed-off-by: NColin Cross <ccross@android.com>

Implement cpufreq support for the Tegra SOC.  DVFS is handled by the
core virtual cpu clock.  The frequencies of the two cores are tied
together, the highest frequency requested by either core determines
the actual frequency.
Signed-off-by: NColin Cross <ccross@android.com>