DMA_DBSA
p->dbs[1] = readl_relaxed(p->base + DMA_DBSA);
p->dbs[0] = readl_relaxed(p->base + DMA_DBSA);
writel_relaxed(p->dbs[0], p->base + DMA_DBSA);
dbsx = DMA_DBSA;
readl_relaxed(p->base + DMA_DBSA),
reg = DMA_DBSA;