Re: [PATCH V2 4/9] ASoC: amd: ps: add SoundWire dma driver dma ops

From: Pierre-Louis Bossart
Date: Mon May 22 2023 - 14:32:20 EST



> +union acp_sdw_dma_count {
> + struct {
> + u32 low;
> + u32 high;
> + } bcount;

indentation seems off?

> + u64 bytescount;
> +};
> +
> +struct sdw_dma_ring_buf_reg {
> + u32 reg_dma_size;
> + u32 reg_fifo_addr;
> + u32 reg_fifo_size;
> + u32 reg_ring_buf_size;
> + u32 reg_ring_buf_addr;
> + u32 water_mark_size_reg;
> + u32 pos_low_reg;
> + u32 pos_high_reg;
> };
>\
> +static void acp63_config_dma(struct acp_sdw_dma_stream *stream, void __iomem *acp_base,
> + u32 stream_id)
> +{
> + u16 page_idx;
> + u32 low, high, val;
> + u32 sdw_dma_pte_offset;
> + dma_addr_t addr;
> +
> + addr = stream->dma_addr;
> + sdw_dma_pte_offset = SDW_PTE_OFFSET(stream->instance);
> + val = sdw_dma_pte_offset + (stream_id * 256);

what is this 256 magic value? use a defined or << 8 ?
> +
> + /* Group Enable */
> + writel(ACP_SDW_SRAM_PTE_OFFSET | BIT(31), acp_base + ACPAXI2AXI_ATU_BASE_ADDR_GRP_2);
> + writel(PAGE_SIZE_4K_ENABLE, acp_base + ACPAXI2AXI_ATU_PAGE_SIZE_GRP_2);
> + for (page_idx = 0; page_idx < stream->num_pages; page_idx++) {
> + /* Load the low address of page int ACP SRAM through SRBM */
> + low = lower_32_bits(addr);
> + high = upper_32_bits(addr);
> +
> + writel(low, acp_base + ACP_SCRATCH_REG_0 + val);
> + high |= BIT(31);
> + writel(high, acp_base + ACP_SCRATCH_REG_0 + val + 4);
> + val += 8;
> + addr += PAGE_SIZE;
> + }
> + writel(0x1, acp_base + ACPAXI2AXI_ATU_CTRL);
> +}