In Mediatek SOCs, the CIRQ is a low power interrupt controller designed to works outside MCUSYS which comprises with Cortex-Ax cores,CCI and GIC. The CIRQ controller is integrated in between MCUSYS and interrupt sources as the second level interrupt controller. The external interrupts which outside MCUSYS will feed through CIRQ then bypass to GIC. In normal mode(where MCUSYS is active), CIRQ is disabled and interrupts will directly issue to MCUSYS. When MCUSYS enters sleep mode, where GIC is power downed. CIRQ will be enabled and monitor all edge trigger interrupts(only edge trigger interrupts will be lost in this scenario). When an edge interrupt is triggered, CIRQ will record the status and generated a pulse signal to GIC when flush command is executed. With CIRQ, MCUSYS can be completely turned off to improve the system power consumption without losing interrupts. change in v4: 1. add some comment to explain CIRQ suspend callback. 2. rebase on 4.11 change in v3: 1. add an explicit cirq range in DT and do the range check in driver. 2. change the option "mediatek,ext-irq-start" to s"mediatek,ext-irq-range". 3. remove mtk_cirq_eoi and clear the irq status in suspend callback. 4. remove some pure copy code. 5. rebase on 4.10-rc2. change in v2: 1. fix coding style issue. 2. change the compatible string. 3. resolve IRQ offset at alloc time. 4. clear irq status in irq_eoi function. 5. rebase on 4.9-rc1. v1: http://lists.infradead.org/pipermail/linux-mediatek/2016-October/007213.html v2: http://lists.infradead.org/pipermail/linux-mediatek/2016-November/007350.html v3: http://lists.infradead.org/pipermail/linux-mediatek/2017-February/008134.html Youlin Pei (3): binding: irqchip: mtk-cirq: Add binding document irqchip: mtk-cirq: Add mediatek mtk-cirq implement ARM: dts: mt2701: Add mtk-cirq node for mt2701 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
