linux_dsm_epyc7002/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7038-l1-intc.txt
Florian Fainelli e14b5e5ff0 dt-bindings: Document brcm, int-fwd-mask property for bcm7038-l1-intc
Indicate that the brcm,int-fwd-mask property is optional and can be set
on platforms which require to leave specific interrupts unmanaged by
Linux and need to retain the firmware configuration.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191024201415.23454-5-f.fainelli@gmail.com
2019-11-10 18:47:47 +00:00

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Broadcom BCM7038-style Level 1 interrupt controller
This block is a first level interrupt controller that is typically connected
directly to one of the HW INT lines on each CPU. Every BCM7xxx set-top chip
since BCM7038 has contained this hardware.
Key elements of the hardware design include:
- 64, 96, 128, or 160 incoming level IRQ lines
- Most onchip peripherals are wired directly to an L1 input
- A separate instance of the register set for each CPU, allowing individual
peripheral IRQs to be routed to any CPU
- Atomic mask/unmask operations
- No polarity/level/edge settings
- No FIFO or priority encoder logic; software is expected to read all
2-5 status words to determine which IRQs are pending
Required properties:
- compatible: should be "brcm,bcm7038-l1-intc"
- reg: specifies the base physical address and size of the registers;
the number of supported IRQs is inferred from the size argument
- interrupt-controller: identifies the node as an interrupt controller
- #interrupt-cells: specifies the number of cells needed to encode an interrupt
source, should be 1.
- interrupts: specifies the interrupt line(s) in the interrupt-parent controller
node; valid values depend on the type of parent interrupt controller
Optional properties:
- brcm,irq-can-wake: If present, this means the L1 controller can be used as a
wakeup source for system suspend/resume.
Optional properties:
- brcm,int-fwd-mask: if present, a bit mask to indicate which interrupts
have already been configured by the firmware and should be left unmanaged.
This should have one 32-bit word per status/set/clear/mask group.
If multiple reg ranges and interrupt-parent entries are present on an SMP
system, the driver will allow IRQ SMP affinity to be set up through the
/proc/irq/ interface. In the simplest possible configuration, only one
reg range and one interrupt-parent is needed.
Example:
periph_intc: periph_intc@1041a400 {
compatible = "brcm,bcm7038-l1-intc";
reg = <0x1041a400 0x30 0x1041a600 0x30>;
interrupt-controller;
#interrupt-cells = <1>;
interrupt-parent = <&cpu_intc>;
interrupts = <2>, <3>;
};