When changing a PLL's rate, it must have no active children. The CPU
clock cannot be stopped, and CPU clock's divider is not used. The old
clock driver used to handle this by internally reparenting the CPU clock
onto a different PLL when changing the CPU clock rate. However, the new
common-clock based clock driver does not do this, and probably cannot do
this due to the locking issues it would cause.
To solve this, have the Tegra cpufreq driver explicitly perform the
reparenting operations itself. This is probably reasonable anyway,
since such reparenting is somewhat a matter of policy (e.g. which
alternate clock source to use, whether to leave the CPU clock a child
of the alternate clock source if it's running at the desired rate),
and hence is something more appropriate for the cpufreq driver than
the core clock driver anyway.
Cc: Prashant Gaikwad <pgaikwad@nvidia.com>
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Use clk_prepare/clk_unprepare as required by the generic clk framework.
Tested on Ventana and Cardhu.
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Disintegrate asm/system.h for ARM.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Russell King <linux@arm.linux.org.uk>
cc: linux-arm-kernel@lists.infradead.org
Two static functions that are not exported:
arch/arm/mach-tegra/cpu-tegra.c:59:5: warning: symbol 'tegra_verify_speed' was not declared. Should it be static?
arch/arm/mach-tegra/cpu-tegra.c:64:14: warning: symbol 'tegra_getspeed' was not declared. Should it be static?
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Type fix:
arch/arm/mach-tegra/cpu-tegra.c:144:14: warning: incorrect type in argument 5 (different signedness)
arch/arm/mach-tegra/cpu-tegra.c:144:14: expected unsigned int *index
arch/arm/mach-tegra/cpu-tegra.c:144:14: got int *<noident>
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This fixes a compilation error in cpu-tegra.c which was introduced in
dc8d966bcc ("ARM: convert PCI defines to variables") which removed the
now obsolete mach/hardware.h from the mach-tegra subtree.
Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin 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: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin 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: Olof Johansson <olof@lixom.net>
Signed-off-by: Colin 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: Colin 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: Colin Cross <ccross@android.com>
Stephen Warren