If interrupts are enabled for a non-root GIC device that uses the
gic-pm driver, when system suspend occurs, the current interrupt
state is not saved and restored correctly and so interrupts do not
work again on resuming the system. Add a late suspend handler to
save and restore the state for these devices.
Suggested-by: Jonathan Hunter <jonathanh@nvidia.com>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
gic-pm driver is using pm-clk framework to manage clock resources, where
clocks remain always ON. This happens on Tegra devices which use BPMP
co-processor to manage the clocks. Calls to BPMP are always blocking and
hence it is necessary to enable/disable clocks during prepare/unprepare
phase respectively. When pm-clk is used, prepare count of clock is not
balanced until pm_clk_remove() happens. Clock is prepared in the driver
probe() and thus prepare count of clock remains non-zero, which in turn
keeps clock ON always.
Please note that above mentioned behavior is specific to Tegra devices
using BPMP for clock management and this should not be seen on other
devices. Though this patch uses clk_bulk APIs to address the mentioned
behavior, this works fine for all devices.
To simplify gic_get_clocks() API is removed and instead probe can do
necessary setup.
Suggested-by: Mohan Kumar D <mkumard@nvidia.com>
Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Commit 498b5fdd40 ("PM / clk: Add support for adding a specific clock
from device-tree") add a new helper function for adding a clock from
device-tree to a device. Update the GIC-PM driver to use this new
function to simplify the driver.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Add a platform driver to support non-root GICs that require runtime
power-management. Currently, only non-root GICs are supported because
the functions, smp_cross_call() and set_handle_irq(), that need to
be called for a root controller are located in the __init section and
so cannot be called by the platform driver.
The GIC platform driver re-uses many functions from the existing GIC
driver including some functions to save and restore the GIC context
during power transitions. The functions for saving and restoring the
GIC context are currently only defined if CONFIG_CPU_PM is enabled and
to ensure that these functions are always defined when the platform
driver is enabled, a dependency on CONFIG_ARM_GIC_PM (which selects the
platform driver) has been added.
In order to re-use the private GIC initialisation code, a new public
function, gic_of_init_child(), has been added which calls various
private functions to initialise the GIC. This is different from the
existing gic_of_init() because it only supports non-root GICs (ie. does
not call smp_cross_call() is set_handle_irq()) and is not located in
the __init section (so can be used by platform drivers). Furthermore,
gic_of_init_child() dynamically allocates memory for the GIC chip data
which is also different from gic_of_init().
There is no specific suspend handling for GICs registered as platform
devices. Non-wakeup interrupts will be disabled by the kernel during
late suspend, however, this alone will not power down the GIC if
interrupts have been requested and not freed. Therefore, requestors of
non-wakeup interrupts will need to free them on entering suspend in
order to power-down the GIC.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
