From 0dcd9f872769547f336741880bc7e721149c8d0a Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 7 Nov 2019 13:21:15 +0100 Subject: irqchip: Add support for Layerscape external interrupt lines The LS1021A allows inverting the polarity of six interrupt lines IRQ[0:5] via the scfg_intpcr register, effectively allowing IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_EDGE_FALLING for those. We just need to check the type, set the relevant bit in INTPCR accordingly, and fixup the type argument before calling the GIC's irq_set_type. In fact, the power-on-reset value of the INTPCR register on the LS1021A is so that all six lines have their polarity inverted. Hence any hardware connected to those lines is unusable without this: If the line is indeed active low, the generic GIC code will reject an irq spec with IRQ_TYPE_LEVEL_LOW, while if the line is active high, we must obviously disable the polarity inversion (writing 0 to the relevant bit) before unmasking the interrupt. Some other Layerscape SOCs (LS1043A, LS1046A) have a similar feature, just with a different number of external interrupt lines (and a different POR value for the INTPCR register). This driver should be prepared for supporting those by properly filling out the device tree node. I have the reference manuals for all three boards, but I've only tested the driver on an LS1021A. Unfortunately, the Kconfig symbol ARCH_LAYERSCAPE only exists on arm64, so do as is done for irq-ls-scfg-msi.c: introduce a new symbol which is set when either ARCH_LAYERSCAPE or SOC_LS1021A is set. Signed-off-by: Rasmus Villemoes Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20191107122115.6244-3-linux@rasmusvillemoes.dk --- drivers/irqchip/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/irqchip/Kconfig') diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig index ccbb8973a324..bbb323462912 100644 --- a/drivers/irqchip/Kconfig +++ b/drivers/irqchip/Kconfig @@ -370,6 +370,10 @@ config MVEBU_PIC config MVEBU_SEI bool +config LS_EXTIRQ + def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE + select MFD_SYSCON + config LS_SCFG_MSI def_bool y if SOC_LS1021A || ARCH_LAYERSCAPE depends on PCI && PCI_MSI -- cgit v1.2.3