blob: 80169360e5b32c383701fe59401ab3c039974874 [file] [log] [blame]
* ARM System MMU Architecture Implementation
ARM SoCs may contain an implementation of the ARM System Memory
Management Unit Architecture, which can be used to provide 1 or 2 stages
of address translation to bus masters external to the CPU.
The SMMU may also raise interrupts in response to various fault
conditions.
** System MMU required properties:
- compatible : Should be one of:
"arm,smmu-v1"
"arm,smmu-v2"
"arm,mmu-400"
"arm,mmu-401"
"arm,mmu-500"
"cavium,smmu-v2"
"qcom,smmu-v2"
"qcom,qsmmu-v500"
depending on the particular implementation and/or the
version of the architecture implemented.
- reg : Base address and size of the SMMU.
- #global-interrupts : The number of global interrupts exposed by the
device.
- interrupts : Interrupt list, with the first #global-irqs entries
corresponding to the global interrupts and any
following entries corresponding to context interrupts,
specified in order of their indexing by the SMMU.
For SMMUv2 implementations, there must be exactly one
interrupt per context bank. In the case of a single,
combined interrupt, it must be listed multiple times.
- mmu-masters : A list of phandles to device nodes representing bus
masters for which the SMMU can provide a translation
and their corresponding StreamIDs (see example below).
Each device node linked from this list must have a
"#stream-id-cells" property, indicating the number of
StreamIDs associated with it.
** System MMU optional properties:
- dma-coherent : Present if page table walks made by the SMMU are
cache coherent with the CPU.
NOTE: this only applies to the SMMU itself, not
masters connected upstream of the SMMU.
- calxeda,smmu-secure-config-access : Enable proper handling of buggy
implementations that always use secure access to
SMMU configuration registers. In this case non-secure
aliases of secure registers have to be used during
SMMU configuration.
- attach-impl-defs : global registers to program at device attach
time. This should be a list of 2-tuples of the format:
<offset reg_value>.
- qcom,fatal-asf : Enable BUG_ON for address size faults. Some hardware
requires special fixups to recover from address size
faults. Rather than applying the fixups just BUG since
address size faults are due to a fundamental programming
error from which we don't care about recovering anyways.
- qcom,skip-init : Disable resetting configuration for all context banks
during device reset. This is useful for targets where
some context banks are dedicated to other execution
environments outside of Linux and those other EEs are
programming their own stream match tables, SCTLR, etc.
Without setting this option we will trample on their
configuration.
- qcom,dynamic : Allow dynamic domains to be attached. This is only
useful if the upstream hardware is capable of switching
between multiple domains within a single context bank.
- clocks : List of clocks to be used during SMMU register access. See
Documentation/devicetree/bindings/clock/clock-bindings.txt
for information about the format. For each clock specified
here, there must be a corresponding entry in clock-names
(see below).
- clock-names : List of clock names corresponding to the clocks specified in
the "clocks" property (above). See
Documentation/devicetree/bindings/clock/clock-bindings.txt
for more info.
- (%s)-supply : Phandle of the regulator that should be powered on during
SMMU register access. (%s) is a string from the
qcom,regulator-names property.
- qcom,regulator-names :
List of strings to use with the (%s)-supply property.
- qcom,msm-bus,name
- qcom,msm-bus,num-cases
- qcom,msm-bus,num-paths
- qcom,msm-bus,vectors-KBps
: Refer to devicetree/bindings/arm/msm/msm_bus.txt
Example:
smmu {
compatible = "arm,smmu-v1";
reg = <0xba5e0000 0x10000>;
#global-interrupts = <2>;
interrupts = <0 32 4>,
<0 33 4>,
<0 34 4>, /* This is the first context interrupt */
<0 35 4>,
<0 36 4>,
<0 37 4>;
/*
* Two DMA controllers, the first with two StreamIDs (0xd01d
* and 0xd01e) and the second with only one (0xd11c).
*/
mmu-masters = <&dma0 0xd01d 0xd01e>,
<&dma1 0xd11c>;
attach-impl-defs = <0x124 0x3>,
<0x128 0xa5>,
<0x12c 0x1>;
};
* Qualcomm MMU-500 TBU Device
The qcom,qsmmu-v500 device implements a number of register regions containing
debug functionality. Each register region maps to a separate tbu from the
arm mmu-500 implementation.
** TBU required properties:
- compatible : Should be one of:
"qcom,qsmmuv500-tbu"
- reg : Base address and size.
- reg-names : "base" and "status-reg" are expected
"base" is the main TBU register region.
"status-reg" indicates whether hw can process a new request.
Example:
smmu {
compatible = "qcom,qsmmu-v500";
tbu@0x1000 {
compatible = "qcom,qsmmuv500-tbu";
regs = <0x1000 0x1000>,
<0x2000 0x8>;
reg-names = "base",
"status-reg";
};
};