irqchip/exiu: Fix acknowledgment of edge triggered interrupts

Currently the EXIU uses the fasteoi interrupt flow that is configured by
it's parent (irq-gic-v3.c). With this flow the only chance to clear the
interrupt request happens during .irq_eoi() and (obviously) this happens
after the interrupt handler has run. EXIU requires edge triggered
interrupts to be acked prior to interrupt handling. Without this we
risk incorrect interrupt dismissal when a new interrupt is delivered
after the handler reads and acknowledges the peripheral but before the
irq_eoi() takes place.

Fix this by clearing the interrupt request from .irq_ack() if we are
configured for edge triggered interrupts. This requires adopting the
fasteoi-ack flow instead of the fasteoi to ensure the ack gets called.

These changes have been tested using the power button on a
Developerbox/SC2A11 combined with some hackery in gpio-keys so I can
play with the different trigger mode [and an mdelay(500) so I can
can check what happens on a double click in both modes].

Fixes: 706cffc1b912 ("irqchip/exiu: Add support for Socionext Synquacer EXIU controller")
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503134541.2566457-1-daniel.thompson@linaro.org

irqchip/exiu: Fix the index of fwspec for IRQ type

Since fwspec->param_count of ACPI node is two, the index of IRQ type
in fwspec->param[] should be 1 rather than 2.

Fixes: 3d090a36c8c8 ("irqchip/exiu: Implement ACPI support")
Signed-off-by: Chen Baozi <chenbaozi@phytium.com.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20201117032015.11805-1-cbz@baozis.org
Cc: stable@vger.kernel.org

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

irqchip/exiu: Implement ACPI support

Expose the existing EXIU hierarchical irqchip domain code to permit
the interrupt controller to be used as the irqchip component of a
GPIO controller on ACPI systems, or as the target of ordinary
interrupt resources.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/exiu: Preparatory refactor for ACPI support

In preparation of adding support for EXIU controller devices described
via ACPI, split the DT init function in a DT specific and a generic part,
where the latter will be reused for ACPI support later.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

irqchip/exiu: Fix return value check in exiu_init()

In case of error, the function of_iomap() returns NULL pointer not
ERR_PTR().

Replace the IS_ERR() test of the return value with NULL test and return
a proper error code.

Fixes: 706cffc1b912 ("irqchip/exiu: Add support for Socionext Synquacer EXIU controller")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Link: https://lkml.kernel.org/r/1510642648-123574-1-git-send-email-weiyongjun1@huawei.com

irqchip/exiu: Add support for Socionext Synquacer EXIU controller

The Socionext Synquacer SoC has an external interrupt unit (EXIU)
that forwards a block of 32 configurable input lines to 32 adjacent
level-high type GICv3 SPIs.

The EXIU has per-interrupt level/edge and polarity controls, and
mask bits that keep the outgoing lines de-asserted, even though
the controller may still latch interrupt conditions that occur
while the line is masked.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>