Commit Graph

5 Commits

Author SHA1 Message Date
Geert Uytterhoeven 414ee536df ARM: psci: Fix indentation in DT bindings
Fix bogus indentation of the PSCI compatible values, reformat.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
2016-01-05 09:28:38 -06:00
Lorenzo Pieralisi 0fc197c7cb drivers: firmware: psci: add PSCI v1.0 DT bindings
PSCI 1.0 is designed to be fully compliant to the PSCI 0.2
specification, with minor differences that are described in the
PSCI specification.

In particular, PSCI v1.0 augments the specification with a new
power_state format (extended stateid - probeable through the
PSCI_FEATURES call), changes some function return codes and
functions usage requirements wrt PSCI 0.2. These changes mean
that 1.0 vs 0.2 compliancy should be enforced through a DT
compatible string that allows firmware to specify 1.0 only
compliancy so that older kernels are prevented from using
PSCI 1.0 FW implementations in a non-compatible way (eg by
calling a 1.0 FW implementation and expecting 0.2 behaviour).

This patch adds PSCI 1.0 DT bindings and related compatible
string.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Jisheng Zhang <jszhang@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
2015-10-02 14:35:17 +01:00
Lorenzo Pieralisi 3f8161b260 Documentation: arm: define DT idle states bindings
ARM based platforms implement a variety of power management schemes that
allow processors to enter idle states at run-time.
The parameters defining these idle states vary on a per-platform basis forcing
the OS to hardcode the state parameters in platform specific static tables
whose size grows as the number of platforms supported in the kernel increases
and hampers device drivers standardization.

Therefore, this patch aims at standardizing idle state device tree bindings
for ARM platforms. Bindings define idle state parameters inclusive of entry
methods and state latencies, to allow operating systems to retrieve the
configuration entries from the device tree and initialize the related power
management drivers, paving the way for common code in the kernel to deal with
idle states and removing the need for static data in current and previous
kernel versions.

ARM64 platforms require the DT to define an entry-method property
for idle states.

On system implementing PSCI as an enable-method to enter low-power
states the PSCI CPU suspend method requires the power_state parameter to
be passed to the PSCI CPU suspend function.

This parameter is specific to a power state and platform specific,
therefore must be provided by firmware to the OS in order to enable
proper call sequence.

Thus, this patch also adds a property in the PSCI bindings that
describes how the PSCI CPU suspend power_state parameter should be
defined in DT in all device nodes that rely on PSCI CPU suspend method usage.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Sebastian Capella <sebcape@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-09-12 10:48:55 +01:00
Ashwin Chaugule e1cd3b361a Documentation: devicetree: Add new binding for PSCIv0.2
The PSCI v0.2+ spec defines standard values for PSCI function IDs.
Add a new binding entry so that pre v0.2 implementations can
use DT entries for function IDs and v0.2+ implementations use
standard entries as defined by the PSCIv0.2 specification.

Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2014-05-15 10:16:24 -04:00
Will Deacon 65397edfa1 ARM: psci: add devicetree binding for describing PSCI firmware
This patch adds a new devicetree binding for describing PSCI firmware
to Linux.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2013-01-10 21:10:20 +00:00