u-boot/doc/device-tree-bindings/misc/intel,irq-router.txt
Bin Meng 51050ff0a2 x86: irq: Support discrete PIRQ routing registers via device tree
Currently both pirq_reg_to_linkno() and pirq_linkno_to_reg() assume
consecutive PIRQ routing control registers. But this is not always
the case on some platforms. Introduce a new device tree property
intel,pirq-regmap to describe how the PIRQ routing register offset
is mapped to the link number and adjust the irq router driver to
utilize the mapping.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
2018-06-13 09:50:57 +08:00

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Intel Interrupt Router Device Binding
=====================================
The device tree node which describes the operation of the Intel Interrupt Router
device is as follows:
Required properties :
- reg : Specifies the interrupt router's PCI configuration space address as
defined by the Open Firmware spec.
- compatible = "intel,irq-router"
- intel,pirq-config : Specifies the IRQ routing register programming mechanism.
Valid values are:
"pci": IRQ routing is controlled by PCI configuration registers
"ibase": IRQ routing is in the memory-mapped IBASE register block
- intel,ibase-offset : IBASE register offset in the interrupt router's PCI
configuration space, required only if intel,pirq-config = "ibase".
- intel,actl-8bit : If ACTL (ACPI control) register width is 8-bit, this must
be specified. The 8-bit ACTL register is seen on ICH series chipset, like
ICH9/Panther Point/etc. On Atom chipset it is a 32-bit register.
- intel,actl-addr : ACTL (ACPI control) register offset. ACTL can be either
in the interrupt router's PCI configuration space, or IBASE.
- intel,pirq-link : Specifies the PIRQ link information with two cells. The
first cell is the register offset that controls the first PIRQ link routing.
The second cell is the total number of PIRQ links the router supports.
- intel,pirq-regmap : Specifies PIRQ routing register offset of all PIRQ links,
encoded as 2 cells a group for each link. The first cell is the PIRQ link
number (0 for PIRQA, 1 for PIRQB, etc). The second cell is the PIRQ routing
register offset from the interrupt router's base address. If this property
is omitted, it indicates a consecutive register offset from the first PIRQ
link, as specified by the first cell of intel,pirq-link.
- intel,pirq-mask : Specifies the IRQ mask representing the 16 IRQs in the
8259 PIC. Bit N is 1 means IRQ N is available to be routed.
- intel,pirq-routing : Specifies all PCI devices' IRQ routing information,
encoded as 3 cells a group for a device. The first cell is the device's PCI
bus number, device number and function number encoding with PCI_BDF() macro.
The second cell is the PCI interrupt pin used by this device. The last cell
is which PIRQ line the PCI interrupt pin is routed to.
Example
-------
#include <dt-bindings/interrupt-router/intel-irq.h>
irq-router@1f,0 {
reg = <0x0000f800 0 0 0 0>;
compatible = "intel,irq-router";
intel,pirq-config = "pci";
intel,pirq-link = <0x60 8>;
intel,pirq-mask = <0xdef8>;
intel,pirq-routing = <
PCI_BDF(0, 2, 0) INTA PIRQA
PCI_BDF(0, 3, 0) INTA PIRQB
PCI_BDF(0, 8, 0) INTA PIRQC
PCI_BDF(0, 8, 1) INTB PIRQD
PCI_BDF(1, 6, 0) INTA PIRQE
PCI_BDF(1, 6, 1) INTB PIRQF
PCI_BDF(1, 6, 2) INTC PIRQG
PCI_BDF(1, 6, 3) INTD PIRQH
>;
};