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| author | Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2019-11-07 15:21:15 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2019-11-10 21:47:49 +0300 |
| commit | 0dcd9f872769547f336741880bc7e721149c8d0a (patch) | |
| tree | 2b027b41535fa923bbf9cf64f5a5fefbc075e816 /drivers/irqchip/Kconfig | |
| parent | 87cd38dfd9e67ffa7c3d3d1a54a2482ed23f1307 (diff) | |
| download | linux-0dcd9f872769547f336741880bc7e721149c8d0a.tar.xz | |
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 <linux@rasmusvillemoes.dk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20191107122115.6244-3-linux@rasmusvillemoes.dk
Diffstat (limited to 'drivers/irqchip/Kconfig')
| -rw-r--r-- | drivers/irqchip/Kconfig | 4 |
1 files changed, 4 insertions, 0 deletions
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 |