linux/arch/arm/mach-sunxi/Kconfig
Samuel Holland 4e34614636 irqchip/sun6i-r: Use a stacked irqchip driver
The R_INTC in the A31 and newer sun8i/sun50i SoCs is more similar to the
original sun4i interrupt controller than the sun7i/sun9i NMI controller.
It is used for two distinct purposes:
 - To control the trigger, latch, and mask for the NMI input pin
 - To provide the interrupt input for the ARISC coprocessor

As this interrupt controller is not documented, information about it
comes from vendor-provided firmware blobs and from experimentation.

Differences from the sun4i interrupt controller appear to be:
 - It only has one or two registers of each kind (max 32 or 64 IRQs)
 - Multiplexing logic is added to support additional inputs
 - There is no FIQ-related logic
 - There is no interrupt priority logic

In order to fulfill its two purposes, this hardware block combines four
types of IRQs. First, the NMI pin is routed to the "IRQ 0" input on this
chip, with a trigger type controlled by the NMI_CTRL_REG. The "IRQ 0
pending" output from this chip, if enabled, is then routed to a SPI IRQ
input on the GIC. In other words, bit 0 of IRQ_ENABLE_REG *does* affect
the NMI IRQ seen at the GIC.

The NMI is followed by a contiguous block of 15 "direct" (my name for
them) IRQ inputs that are connected in parallel to both R_INTC and the
GIC. Or in other words, these bits of IRQ_ENABLE_REG *do not* affect the
IRQs seen at the GIC.

Following the direct IRQs are the ARISC's copy of banked IRQs for shared
peripherals. These are not relevant to Linux. The remaining IRQs are
connected to a multiplexer and provide access to the first (up to) 128
SPIs from the ARISC. This range of SPIs overlaps with the direct IRQs.

Because of the 1:1 correspondence between R_INTC and GIC inputs, this is
a perfect scenario for using a stacked irqchip driver. We want to hook
into setting the NMI trigger type, but not actually handle any IRQ here.

To allow access to all multiplexed IRQs, this driver requires a new
binding where the interrupt number matches the GIC interrupt number.
(This moves the NMI from number 0 to 32 or 96, depending on the SoC.)
For simplicity, copy the three-cell GIC binding; this disambiguates
interrupt 0 in the old binding (the NMI) from interrupt 0 in the new
binding (SPI 0) by the number of cells.

Since R_INTC is in the always-on power domain, and its output is visible
to the power management coprocessor, a stacked irqchip driver provides a
simple way to add wakeup support to any of its IRQs. That is the next
patch; for now, just the NMI is moved over.

This commit mostly reverts commit 173bda53b3 ("irqchip/sunxi-nmi:
Support sun6i-a31-r-intc compatible").

Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210118055040.21910-4-samuel@sholland.org
2021-01-21 20:21:49 +00:00

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# SPDX-License-Identifier: GPL-2.0-only
menuconfig ARCH_SUNXI
bool "Allwinner SoCs"
depends on ARCH_MULTI_V5 || ARCH_MULTI_V7
select ARCH_HAS_RESET_CONTROLLER
select CLKSRC_MMIO
select GENERIC_IRQ_CHIP
select GPIOLIB
select IRQ_DOMAIN_HIERARCHY
select IRQ_FASTEOI_HIERARCHY_HANDLERS
select PINCTRL
select PM_OPP
select SUN4I_TIMER
select RESET_CONTROLLER
help
Support for Allwinner ARM-based family of processors
if ARCH_SUNXI
if ARCH_MULTI_V7
config MACH_SUN4I
bool "Allwinner A10 (sun4i) SoCs support"
default ARCH_SUNXI
config MACH_SUN5I
bool "Allwinner A10s / A13 (sun5i) SoCs support"
default ARCH_SUNXI
select SUN5I_HSTIMER
config MACH_SUN6I
bool "Allwinner A31 (sun6i) SoCs support"
default ARCH_SUNXI
select ARM_GIC
select MFD_SUN6I_PRCM
select SUN5I_HSTIMER
config MACH_SUN7I
bool "Allwinner A20 (sun7i) SoCs support"
default ARCH_SUNXI
select ARM_GIC
select ARM_PSCI
select ARCH_SUPPORTS_BIG_ENDIAN
select HAVE_ARM_ARCH_TIMER
select SUN5I_HSTIMER
config MACH_SUN8I
bool "Allwinner sun8i Family SoCs support"
default ARCH_SUNXI
select ARM_GIC
select MFD_SUN6I_PRCM
config MACH_SUN9I
bool "Allwinner (sun9i) SoCs support"
default ARCH_SUNXI
select ARM_GIC
config ARCH_SUNXI_MC_SMP
bool
depends on SMP
default MACH_SUN9I || MACH_SUN8I
select ARM_CCI400_PORT_CTRL
select ARM_CPU_SUSPEND
endif
if ARCH_MULTI_V5
config MACH_SUNIV
bool "Allwinner ARMv5 F-series (suniv) SoCs support"
default ARCH_SUNXI
help
Support for Allwinner suniv ARMv5 SoCs.
(F1C100A, F1C100s, F1C200s, F1C500, F1C600)
endif
endif