STM32_DMA_SM1AR
dma_smar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(id));
u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id));
stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar);
stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar);
stm32_dma_read(dmadev, STM32_DMA_SM1AR(id)));
stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sg_req->chan_reg.dma_sm1ar);
stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), sm1ar + offset);