chan_to_axi_dmac
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct axi_dmac *dmac = chan_to_axi_dmac(chan);
struct axi_dmac *dmac = chan_to_axi_dmac(desc->chan);