[][src]Function esp_idf_sys::spicommon_setup_dma_desc_links

pub unsafe extern "C" fn spicommon_setup_dma_desc_links(
    dmadesc: *mut lldesc_t,
    len: c_int,
    data: *const u8,
    isrx: bool
)

@brief Setup a DMA link chain

This routine will set up a chain of linked DMA descriptors in the array pointed to by dmadesc. Enough DMA descriptors will be used to fit the buffer of len bytes in, and the descriptors will point to the corresponding positions in buffer and linked together. The end result is that feeding dmadesc[0] into DMA hardware results in the entirety len bytes of data being read or written.

@param dmadesc Pointer to array of DMA descriptors big enough to be able to convey len bytes @param len Length of buffer @param data Data buffer to use for DMA transfer @param isrx True if data is to be written into data, false if it's to be read from data.