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Diffstat (limited to 'Documentation/devicetree/bindings/powerpc/fsl/mpic.txt')
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1 files changed, 211 insertions, 42 deletions
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt index 71e39cf3215..8aa10f45ebe 100644 --- a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt +++ b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt @@ -1,42 +1,211 @@ -* OpenPIC and its interrupt numbers on Freescale's e500/e600 cores - -The OpenPIC specification does not specify which interrupt source has to -become which interrupt number. This is up to the software implementation -of the interrupt controller. The only requirement is that every -interrupt source has to have an unique interrupt number / vector number. -To accomplish this the current implementation assigns the number zero to -the first source, the number one to the second source and so on until -all interrupt sources have their unique number. -Usually the assigned vector number equals the interrupt number mentioned -in the documentation for a given core / CPU. This is however not true -for the e500 cores (MPC85XX CPUs) where the documentation distinguishes -between internal and external interrupt sources and starts counting at -zero for both of them. - -So what to write for external interrupt source X or internal interrupt -source Y into the device tree? Here is an example: - -The memory map for the interrupt controller in the MPC8544[0] shows, -that the first interrupt source starts at 0x5_0000 (PIC Register Address -Map-Interrupt Source Configuration Registers). This source becomes the -number zero therefore: - External interrupt 0 = interrupt number 0 - External interrupt 1 = interrupt number 1 - External interrupt 2 = interrupt number 2 - ... -Every interrupt number allocates 0x20 bytes register space. So to get -its number it is sufficient to shift the lower 16bits to right by five. -So for the external interrupt 10 we have: - 0x0140 >> 5 = 10 - -After the external sources, the internal sources follow. The in core I2C -controller on the MPC8544 for instance has the internal source number -27. Oo obtain its interrupt number we take the lower 16bits of its memory -address (0x5_0560) and shift it right: - 0x0560 >> 5 = 43 - -Therefore the I2C device node for the MPC8544 CPU has to have the -interrupt number 43 specified in the device tree. - -[0] MPC8544E PowerQUICCTM III, Integrated Host Processor Family Reference Manual - MPC8544ERM Rev. 1 10/2007 +===================================================================== +Freescale MPIC Interrupt Controller Node +Copyright (C) 2010,2011 Freescale Semiconductor Inc. +===================================================================== + +The Freescale MPIC interrupt controller is found on all PowerQUICC +and QorIQ processors and is compatible with the Open PIC. The +notable difference from Open PIC binding is the addition of 2 +additional cells in the interrupt specifier defining interrupt type +information. + +PROPERTIES + + - compatible + Usage: required + Value type: <string> + Definition: Shall include "fsl,mpic". Freescale MPIC + controllers compatible with this binding have Block + Revision Registers BRR1 and BRR2 at offset 0x0 and + 0x10 in the MPIC. + + - reg + Usage: required + Value type: <prop-encoded-array> + Definition: A standard property. Specifies the physical + offset and length of the device's registers within the + CCSR address space. + + - interrupt-controller + Usage: required + Value type: <empty> + Definition: Specifies that this node is an interrupt + controller + + - #interrupt-cells + Usage: required + Value type: <u32> + Definition: Shall be 2 or 4. A value of 2 means that interrupt + specifiers do not contain the interrupt-type or type-specific + information cells. + + - #address-cells + Usage: required + Value type: <u32> + Definition: Shall be 0. + + - pic-no-reset + Usage: optional + Value type: <empty> + Definition: The presence of this property specifies that the + MPIC must not be reset by the client program, and that + the boot program has initialized all interrupt source + configuration registers to a sane state-- masked or + directed at other cores. This ensures that the client + program will not receive interrupts for sources not belonging + to the client. The presence of this property also mandates + that any initialization related to interrupt sources shall + be limited to sources explicitly referenced in the device tree. + +INTERRUPT SPECIFIER DEFINITION + + Interrupt specifiers consists of 4 cells encoded as + follows: + + <1st-cell> interrupt-number + + Identifies the interrupt source. The meaning + depends on the type of interrupt. + + Note: If the interrupt-type cell is undefined + (i.e. #interrupt-cells = 2), this cell + should be interpreted the same as for + interrupt-type 0-- i.e. an external or + normal SoC device interrupt. + + <2nd-cell> level-sense information, encoded as follows: + 0 = low-to-high edge triggered + 1 = active low level-sensitive + 2 = active high level-sensitive + 3 = high-to-low edge triggered + + <3rd-cell> interrupt-type + + The following types are supported: + + 0 = external or normal SoC device interrupt + + The interrupt-number cell contains + the SoC device interrupt number. The + type-specific cell is undefined. The + interrupt-number is derived from the + MPIC a block of registers referred to as + the "Interrupt Source Configuration Registers". + Each source has 32-bytes of registers + (vector/priority and destination) in this + region. So interrupt 0 is at offset 0x0, + interrupt 1 is at offset 0x20, and so on. + + 1 = error interrupt + + The interrupt-number cell contains + the SoC device interrupt number for + the error interrupt. The type-specific + cell identifies the specific error + interrupt number. + + 2 = MPIC inter-processor interrupt (IPI) + + The interrupt-number cell identifies + the MPIC IPI number. The type-specific + cell is undefined. + + 3 = MPIC timer interrupt + + The interrupt-number cell identifies + the MPIC timer number. The type-specific + cell is undefined. + + <4th-cell> type-specific information + + The type-specific cell is encoded as follows: + + - For interrupt-type 1 (error interrupt), + the type-specific cell contains the + bit number of the error interrupt in the + Error Interrupt Summary Register. + +EXAMPLE 1 + /* + * mpic interrupt controller with 4 cells per specifier + */ + mpic: pic@40000 { + compatible = "fsl,mpic"; + interrupt-controller; + #interrupt-cells = <4>; + #address-cells = <0>; + reg = <0x40000 0x40000>; + }; + +EXAMPLE 2 + /* + * The MPC8544 I2C controller node has an internal + * interrupt number of 27. As per the reference manual + * this corresponds to interrupt source configuration + * registers at 0x5_0560. + * + * The interrupt source configuration registers begin + * at 0x5_0000. + * + * To compute the interrupt specifier interrupt number + * + * 0x560 >> 5 = 43 + * + * The interrupt source configuration registers begin + * at 0x5_0000, and so the i2c vector/priority registers + * are at 0x5_0560. + */ + i2c@3000 { + #address-cells = <1>; + #size-cells = <0>; + cell-index = <0>; + compatible = "fsl-i2c"; + reg = <0x3000 0x100>; + interrupts = <43 2>; + interrupt-parent = <&mpic>; + dfsrr; + }; + + +EXAMPLE 3 + /* + * Definition of a node defining the 4 + * MPIC IPI interrupts. Note the interrupt + * type of 2. + */ + ipi@410a0 { + compatible = "fsl,mpic-ipi"; + reg = <0x40040 0x10>; + interrupts = <0 0 2 0 + 1 0 2 0 + 2 0 2 0 + 3 0 2 0>; + }; + +EXAMPLE 4 + /* + * Definition of a node defining the MPIC + * global timers. Note the interrupt + * type of 3. + */ + timer0: timer@41100 { + compatible = "fsl,mpic-global-timer"; + reg = <0x41100 0x100>; + interrupts = <0 0 3 0 + 1 0 3 0 + 2 0 3 0 + 3 0 3 0>; + }; + +EXAMPLE 5 + /* + * Definition of an error interrupt (interupt type 1). + * SoC interrupt number is 16 and the specific error + * interrupt bit in the error interrupt summary register + * is 23. + */ + memory-controller@8000 { + compatible = "fsl,p4080-memory-controller"; + reg = <0x8000 0x1000>; + interrupts = <16 2 1 23>; + }; |