linux/Documentation/devicetree/bindings/iommu/ti,omap-iommu.txt
Suman Anna c0e44929b5 Documentation: dt: Update OMAP iommu bindings for DRA7 DSPs
The DSP processor sub-systems on DRA7xx have two MMU instances
each, one for the processor core and the other for an internal
EDMA block. These MMUs need an additional shared register to be
programmed in the DSP_SYSTEM sub-module to be enabled properly.

The OMAP IOMMU bindings is updated to account for this additional
syscon property required for these DSP IOMMU instances on DRA7xx
SoCs. A new compatible "ti,dra7-dsp-iommu" is also defined to
distinguish these devices specifically from other DRA7 IOMMU
devices.

An example of the DRA7 DSP IOMMU nodes is also added to the
document for clarity.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-10-14 14:35:47 +02:00

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OMAP2+ IOMMU
Required properties:
- compatible : Should be one of,
"ti,omap2-iommu" for OMAP2/OMAP3 IOMMU instances
"ti,omap4-iommu" for OMAP4/OMAP5 IOMMU instances
"ti,dra7-dsp-iommu" for DRA7xx DSP IOMMU instances
"ti,dra7-iommu" for DRA7xx IOMMU instances
- ti,hwmods : Name of the hwmod associated with the IOMMU instance
- reg : Address space for the configuration registers
- interrupts : Interrupt specifier for the IOMMU instance
- #iommu-cells : Should be 0. OMAP IOMMUs are all "single-master" devices,
and needs no additional data in the pargs specifier. Please
also refer to the generic bindings document for more info
on this property,
Documentation/devicetree/bindings/iommu/iommu.txt
Optional properties:
- ti,#tlb-entries : Number of entries in the translation look-aside buffer.
Should be either 8 or 32 (default: 32)
- ti,iommu-bus-err-back : Indicates the IOMMU instance supports throwing
back a bus error response on MMU faults.
- ti,syscon-mmuconfig : Should be a pair of the phandle to the DSP_SYSTEM
syscon node that contains the additional control
register for enabling the MMU, and the MMU instance
number (0-indexed) within the sub-system. This property
is required for DSP IOMMU instances on DRA7xx SoCs. The
instance number should be 0 for DSP MDMA MMUs and 1 for
DSP EDMA MMUs.
Example:
/* OMAP3 ISP MMU */
mmu_isp: mmu@480bd400 {
#iommu-cells = <0>;
compatible = "ti,omap2-iommu";
reg = <0x480bd400 0x80>;
interrupts = <24>;
ti,hwmods = "mmu_isp";
ti,#tlb-entries = <8>;
};
/* DRA74x DSP2 MMUs */
mmu0_dsp2: mmu@41501000 {
compatible = "ti,dra7-dsp-iommu";
reg = <0x41501000 0x100>;
interrupts = <GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>;
ti,hwmods = "mmu0_dsp2";
#iommu-cells = <0>;
ti,syscon-mmuconfig = <&dsp2_system 0x0>;
};
mmu1_dsp2: mmu@41502000 {
compatible = "ti,dra7-dsp-iommu";
reg = <0x41502000 0x100>;
interrupts = <GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
ti,hwmods = "mmu1_dsp2";
#iommu-cells = <0>;
ti,syscon-mmuconfig = <&dsp2_system 0x1>;
};