ARM: mvebu: switch to using gpiod API in pm-board code

This switches PM code to use the newer gpiod API instead of legacy
gpio API that we want to retire.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - gpl-2.0_56.RULE (part 1)

Based on the normalized pattern:

this file is licensed under the terms of the gnu general public
license version 2 this program is licensed as is without any warranty
of any kind whether express or implied

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference.

Reviewed-by: Allison Randal <allison@lohutok.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: mvebu: fix a leaked reference by adding missing of_node_put

The call to of_get_next_child returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./arch/arm/mach-mvebu/pm-board.c:135:2-8: ERROR: missing of_node_put; acquired a node pointer with refcount incremented on line 88, but without a corresponding object release within this functio

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Gregory Clement <gregory.clement@bootlin.com>
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

ARM: mvebu: Add standby support

Until now only one Armada XP and one Armada 388 based board supported
suspend to ram. However, most of the recent mvebu SoCs can support the
standby mode. Unlike for the suspend to ram, nothing special has to be
done for these SoCs. This patch allows the system to use the standby
mode on Armada 370, 38x, 39x and XP SoCs. There are issues with the
Armada 375, and the support might be added (if possible) in a future
patch.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: Use __init for the PM initialization functions

mvebu_pm_init and mvebu_armada_pm_init are only called during boot, so
flag them with __init and save some memory.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

ARM: mvebu: prepare pm-board.c for the introduction of Armada 38x support

The pm-board.c code contains the board-specific logic to enter suspend
to RAM. Until now, the code supported only the Armada XP GP board, so
all functions and symbols were named with armada_xp_gp. However, it
turns out that the Armada 388 GP also uses the same 3 GPIOs protocol
to talk to the PIC microcontroller that controls the power supply.

Since we are going to re-use the same code with no change for Armada
38x, this commit renames the functions and symbols to use just
"armada" instead of "armada_xp_gp". Better names can be found if one
day other boards having a different protocol/mechanism are supported
in the kernel.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

ARM: mvebu: fix suspend to RAM on big-endian configurations

The current Armada XP suspend to RAM implementation, as added in
commit 27432825ae19f ("ARM: mvebu: Armada XP GP specific
suspend/resume code") does not handle big-endian configurations
properly: the small bit of assembly code putting the DRAM in
self-refresh and toggling the GPIOs to turn off power forgets to
convert the values to little-endian.

This commit fixes that by making sure the two values we will write to
the DRAM controller register and GPIO register are already in
little-endian before entering the critical assembly code.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: <stable@vger.kernel.org> # v3.19+
Fixes: 27432825ae19f ("ARM: mvebu: Armada XP GP specific suspend/resume code")

ARM: mvebu: Armada XP GP specific suspend/resume code

On the Armada XP GP platform, entering suspend to RAM state is
triggering by talking to an external PIC micro-controller connected to
the SoC using 3 GPIOs. There is then a small magic sequence of GPIO
toggling that needs to be used to tell the PIC to turn off the SoC.

The code uses the Device Tree to find out which GPIOs are used to
connect to the PIC micro-controller, and then registers its
mvebu_armada_xp_gp_pm_enter() callback to the SoC-level PM code. The
SoC PM code will call back into this registered function at the very
end of the suspend procedure.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1416585613-2113-12-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>