diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/dma/edma.h | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h index da7a5cc93ad4..17cbe7ce55aa 100644 --- a/include/linux/dma/edma.h +++ b/include/linux/dma/edma.h @@ -63,6 +63,38 @@ enum dw_edma_chip_flags { }; /** + * enum dw_edma_ch_irq_mode - per-channel interrupt routing control + * @DW_EDMA_CH_IRQ_LOCAL: local interrupt only (edma_int[]) + * @DW_EDMA_CH_IRQ_REMOTE: remote interrupt only (IMWr/MSI), without + * delivering local edma_int[]. + * + * DesignWare EP eDMA can signal interrupts locally through the edma_int[] + * bus, and remotely using posted memory writes (IMWr) that may be + * interpreted as MSI/MSI-X by the RC. + * + * For the v0 eDMA linked-list programming path, DMA_*_INT_MASK gates the local + * edma_int[] assertion, while there is no dedicated per-channel mask for IMWr + * generation. To request a remote-only interrupt, Synopsys recommends setting + * both LIE and RIE, and masking the local interrupt in DMA_*_INT_MASK. See the + * DesignWare endpoint databook 6.30a, Linked List Mode interrupt handling + * ("Software Programming of an Endpoint's LIE and RIE Bits for Linked List + * Transfers", Attention). + * + * A local (DW_EDMA_CHIP_LOCAL) instance never issues transfers on a + * remote-routed channel: REMOTE routing on such an instance denotes a channel + * handed over to and driven by the remote side, and the recipe above is + * applied by the driving instance. + * + * HDMA linked-list watermark interrupts have the same LWIE/RWIE guidance. HDMA + * non-linked-list mode has dedicated local and remote stop/abort interrupt + * enables. + */ +enum dw_edma_ch_irq_mode { + DW_EDMA_CH_IRQ_LOCAL = 0, + DW_EDMA_CH_IRQ_REMOTE, +}; + +/** * struct dw_edma_chip - representation of DesignWare eDMA controller hardware * @dev: struct device of the eDMA controller * @nr_irqs: total number of DMA IRQs |