spi: rockchip: adjust dma watermark and burstlen

Signal tx dma when spi fifo is less than half full,
and limit tx bursts to half the fifo length.

Clamp rx burst length to 1 to avoid alignment issues.

Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index fdcf3076681b5eeffb1885b428c8d00ff2682d2f..2f825702cd9061fe4bd76d29ee18d555192a4a16 100644 (file)
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -455,10 +455,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
                rxconf.direction = rs->dma_rx.direction;
                rxconf.src_addr = rs->dma_rx.addr;
                rxconf.src_addr_width = rs->n_bytes;
-               if (rs->dma_caps.max_burst > 4)
-                       rxconf.src_maxburst = 4;
-               else
-                       rxconf.src_maxburst = 1;
+               rxconf.src_maxburst = 1;
                dmaengine_slave_config(rs->dma_rx.ch, &rxconf);
 
                rxdesc = dmaengine_prep_slave_sg(
@@ -477,10 +474,7 @@ static int rockchip_spi_prepare_dma(struct rockchip_spi *rs)
                txconf.direction = rs->dma_tx.direction;
                txconf.dst_addr = rs->dma_tx.addr;
                txconf.dst_addr_width = rs->n_bytes;
-               if (rs->dma_caps.max_burst > 4)
-                       txconf.dst_maxburst = 4;
-               else
-                       txconf.dst_maxburst = 1;
+               txconf.dst_maxburst = rs->fifo_len / 2;
                dmaengine_slave_config(rs->dma_tx.ch, &txconf);
 
                txdesc = dmaengine_prep_slave_sg(
@@ -578,7 +572,7 @@ static void rockchip_spi_config(struct rockchip_spi *rs)
        writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_TXFTLR);
        writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_RXFTLR);
 
-       writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMATDLR);
+       writel_relaxed(rs->fifo_len / 2 - 1, rs->regs + ROCKCHIP_SPI_DMATDLR);
        writel_relaxed(0, rs->regs + ROCKCHIP_SPI_DMARDLR);
        writel_relaxed(dmacr, rs->regs + ROCKCHIP_SPI_DMACR);