Unverified Commit 4d9ca632 authored by Jon Lin's avatar Jon Lin Committed by Mark Brown
Browse files

spi: rockchip: Config spi rx dma burst size depend on xfer length 



The burst length can be adjusted according to the transmission
length to improve the transmission rate

Signed-off-by: default avatarJon Lin <jon.lin@rock-chips.com>
Tested-by: default avatarEmil Renner Berthing <kernel@esmil.dk>
Reviewed-by: default avatarEmil Renner Berthing <kernel@esmil.dk>
Link: https://lore.kernel.org/r/20200723004356.6390-1-jon.lin@rock-chips.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 15b413d9

drivers/spi/spi-rockchip.c

+17 −2
Original line number Diff line number Diff line
@@ -384,6 +384,19 @@ static void rockchip_spi_dma_txcb(void *data) 
	spi_finalize_current_transfer(ctlr);

}



static u32 rockchip_spi_calc_burst_size(u32 data_len)

{

	u32 i;



	/* burst size: 1, 2, 4, 8 */

	for (i = 1; i < 8; i <<= 1) {

		if (data_len & i)

			break;

	}



	return i;

}



static int rockchip_spi_prepare_dma(struct rockchip_spi *rs,

		struct spi_controller *ctlr, struct spi_transfer *xfer)

{
@@ -397,7 +410,8 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs, 
			.direction = DMA_DEV_TO_MEM,

			.src_addr = rs->dma_addr_rx,

			.src_addr_width = rs->n_bytes,

			.src_maxburst = 1,

			.src_maxburst = rockchip_spi_calc_burst_size(xfer->len /

								     rs->n_bytes),

		};



		dmaengine_slave_config(ctlr->dma_rx, &rxconf);
@@ -525,7 +539,8 @@ static void rockchip_spi_config(struct rockchip_spi *rs, 
		writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);



	writel_relaxed(rs->fifo_len / 2, rs->regs + ROCKCHIP_SPI_DMATDLR);

	writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);

	writel_relaxed(rockchip_spi_calc_burst_size(xfer->len / rs->n_bytes) - 1,

		       rs->regs + ROCKCHIP_SPI_DMARDLR);

	writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);



	/* the hardware only supports an even clock divisor, so

CRA Git | Maintained and supported by SUSTech CRA and CCSE