CPU suspend is the standard kernel interface to be used to enter
low-power states on ARM64 systems. Current cpu_suspend implementation
by default assumes that all low power states are losing the CPU context,
so the CPU registers must be saved and cleaned to DRAM upon state
entry. Furthermore, the current cpu_suspend() implementation assumes
that if the CPU suspend back-end method returns when called, this has
to be considered an error regardless of the return code (which can be
successful) since the CPU was not expected to return from a code path that
is different from cpu_resume code path - eg returning from the reset vector.
All in all this means that the current API does not cope well with low-power
states that preserve the CPU context when entered (ie retention states),
since first of all the context is saved for nothing on state entry for
those states and a successful state entry can return as a normal function
return, which is considered an error by the current CPU suspend
implementation.
This patch refactors the cpu_suspend() API so that it can be split in
two separate functionalities. The arm64 cpu_suspend API just provides
a wrapper around CPU suspend operation hook. A new function is
introduced (for architecture code use only) for states that require
context saving upon entry:
__cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
__cpu_suspend() saves the context on function entry and calls the
so called suspend finisher (ie fn) to complete the suspend operation.
The finisher is not expected to return, unless it fails in which case
the error is propagated back to the __cpu_suspend caller.
The API refactoring results in the following pseudo code call sequence for a
suspending CPU, when triggered from a kernel subsystem:
/*
* int cpu_suspend(unsigned long idx)
* @idx: idle state index
*/
{
-> cpu_suspend(idx)
|---> CPU operations suspend hook called, if present
|--> if (retention_state)
|--> direct suspend back-end call (eg PSCI suspend)
else
|--> __cpu_suspend(idx, &back_end_finisher);
}
By refactoring the cpu_suspend API this way, the CPU operations back-end
has a chance to detect whether idle states require state saving or not
and can call the required suspend operations accordingly either through
simple function call or indirectly through __cpu_suspend() which carries out
state saving and suspend finisher dispatching to complete idle state entry.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 714f599255)
Suspend init function must be marked as __init, since it is not needed
after the kernel has booted. This patch moves the cpu_suspend_init()
function to the __init section.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 18ab7db6b7)
CPUs are also registered as devices but the of_node in these cpu
devices are not initialized. Currently different drivers requiring
to access cpu device node are parsing the nodes themselves and
initialising the of_node in cpu device.
The of_node in all the cpu devices needs to be initialized properly
and at one place. The best place to update this is CPU subsystem
driver when registering the cpu devices.
The OF/DT core library now provides of_get_cpu_node to retrieve a cpu
device node for a given logical index by abstracting the architecture
specific details.
This patch uses of_get_cpu_node to assign of_node when registering the
cpu devices.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
(cherry picked from commit f86e4718f2)
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
Conflicts:
drivers/base/cpu.c
If i2c error, the driver may call rtc_year_days with month -1, which will
cause crash. Fix this by never call rtc_year_days at all.
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
1. check act and size in win2 win3 layer;
2. add support yuv420sp nv21 data format;
3. in read bit func,not need to backup reg;
4. complete get win state func;
Signed-off-by: hjc <hjc@rock-chips.com>
It is necessary to enable hclk_vio_h2p\pclk_vio_h2p\hclk_vio_ahb_arbi
for devices under power doamin PD_VIO wen they work. Thus these clks
are modified to be parent of other clks from hclk_vio.
Signed-off-by: dkl <dkl@rock-chips.com>
Introduce feature SUPPORT_YCBCR_INPUT. If VOP can
output YCbCr, VOP output color mode is equal to HDMI
output color mode. Otherwise, VOP just output RGB,
HDMI will conver color space.
Signed-off-by: Zheng Yang <zhengyang@rock-chips.com>
