Cristian Birsan | edf2194 | 2016-01-13 18:15:34 -0700 | [diff] [blame] | 1 | Microchip PIC32 Interrupt Controller |
| 2 | ==================================== |
| 3 | |
| 4 | The Microchip PIC32 contains an Enhanced Vectored Interrupt Controller (EVIC). |
| 5 | It handles all internal and external interrupts. This controller exists outside |
| 6 | of the CPU and is the arbitrator of all interrupts (including interrupts from |
| 7 | the CPU itself) before they are presented to the CPU. |
| 8 | |
| 9 | External interrupts have a software configurable edge polarity. Non external |
| 10 | interrupts have a type and polarity that is determined by the source of the |
| 11 | interrupt. |
| 12 | |
| 13 | Required properties |
| 14 | ------------------- |
| 15 | |
| 16 | - compatible: Should be "microchip,pic32mzda-evic" |
| 17 | - reg: Specifies physical base address and size of register range. |
| 18 | - interrupt-controller: Identifies the node as an interrupt controller. |
| 19 | - #interrupt cells: Specifies the number of cells used to encode an interrupt |
| 20 | source connected to this controller. The value shall be 2 and interrupt |
| 21 | descriptor shall have the following format: |
| 22 | |
| 23 | <hw_irq irq_type> |
| 24 | |
| 25 | hw_irq - represents the hardware interrupt number as in the data sheet. |
| 26 | irq_type - is used to describe the type and polarity of an interrupt. For |
| 27 | internal interrupts use IRQ_TYPE_EDGE_RISING for non persistent interrupts and |
| 28 | IRQ_TYPE_LEVEL_HIGH for persistent interrupts. For external interrupts use |
| 29 | IRQ_TYPE_EDGE_RISING or IRQ_TYPE_EDGE_FALLING to select the desired polarity. |
| 30 | |
| 31 | Optional properties |
| 32 | ------------------- |
| 33 | - microchip,external-irqs: u32 array of external interrupts with software |
| 34 | polarity configuration. This array corresponds to the bits in the INTCON |
| 35 | SFR. |
| 36 | |
| 37 | Example |
| 38 | ------- |
| 39 | |
| 40 | evic: interrupt-controller@1f810000 { |
| 41 | compatible = "microchip,pic32mzda-evic"; |
| 42 | interrupt-controller; |
| 43 | #interrupt-cells = <2>; |
| 44 | reg = <0x1f810000 0x1000>; |
| 45 | microchip,external-irqs = <3 8 13 18 23>; |
| 46 | }; |
| 47 | |
| 48 | Each device/peripheral must request its interrupt line with the associated type |
| 49 | and polarity. |
| 50 | |
| 51 | Internal interrupt DTS snippet |
| 52 | ------------------------------ |
| 53 | |
| 54 | device@1f800000 { |
| 55 | ... |
| 56 | interrupts = <113 IRQ_TYPE_LEVEL_HIGH>; |
| 57 | ... |
| 58 | }; |
| 59 | |
| 60 | External interrupt DTS snippet |
| 61 | ------------------------------ |
| 62 | |
| 63 | device@1f800000 { |
| 64 | ... |
| 65 | interrupts = <3 IRQ_TYPE_EDGE_RISING>; |
| 66 | ... |
| 67 | }; |