The SDMA engine is a programmable controller in i.MX6, and each peripheral has its own copy function in this controller. One uses this enum to determine their addresses:
enum sdma_peripheral_type { IMX_DMATYPE_SSI, /* MCU domain SSI */ IMX_DMATYPE_SSI_SP, /* Shared SSI */ IMX_DMATYPE_MMC, /* MMC */ IMX_DMATYPE_SDHC, /* SDHC */ IMX_DMATYPE_UART, /* MCU domain UART */ IMX_DMATYPE_UART_SP, /* Shared UART */ IMX_DMATYPE_FIRI, /* FIRI */ IMX_DMATYPE_CSPI, /* MCU domain CSPI */ IMX_DMATYPE_CSPI_SP, /* Shared CSPI */ IMX_DMATYPE_SIM, /* SIM */ IMX_DMATYPE_ATA, /* ATA */ IMX_DMATYPE_CCM, /* CCM */ IMX_DMATYPE_EXT, /* External peripheral */ IMX_DMATYPE_MSHC, /* Memory Stick Host Controller */ IMX_DMATYPE_MSHC_SP, ...
