From 6cb6aa602b541d2b2f864c47b6a3f62e3eefe282 Mon Sep 17 00:00:00 2001 From: Jagan Teki Date: Wed, 27 Feb 2019 20:02:05 +0530 Subject: [PATCH] spi: sun4i: Poll for rxfifo to be filled up To drain rx fifo the fifo need to poll for how much data has been filled up in rx fifo. To achieve this, the current code is using wait_for_bit logic on control register with exchange burst mode mask, which is not a proper way of waiting for fifo filled up. So, add code for polling rxfifo to be filled up using fifo status register. Signed-off-by: Jagan Teki Reviewed-by: Andre Przywara --- drivers/spi/sun4i_spi.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/spi/sun4i_spi.c b/drivers/spi/sun4i_spi.c index 38cc743c61..f5f2d5635a 100644 --- a/drivers/spi/sun4i_spi.c +++ b/drivers/spi/sun4i_spi.c @@ -31,6 +31,8 @@ #include +#include + #define SUN4I_FIFO_DEPTH 64 #define SUN4I_RXDATA_REG 0x00 @@ -46,7 +48,6 @@ #define SUN4I_CTL_LMTF BIT(6) #define SUN4I_CTL_TF_RST BIT(8) #define SUN4I_CTL_RF_RST BIT(9) -#define SUN4I_CTL_XCH_MASK 0x0400 #define SUN4I_CTL_XCH BIT(10) #define SUN4I_CTL_CS_MASK 0x3000 #define SUN4I_CTL_CS(cs) (((cs) << 12) & SUN4I_CTL_CS_MASK) @@ -308,7 +309,7 @@ static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen, struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev); u32 len = bitlen / 8; - u32 reg; + u32 reg, rx_fifocnt; u8 nbytes; int ret; @@ -343,10 +344,12 @@ static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen, reg = readl(&priv->regs->ctl); writel(reg | SUN4I_CTL_XCH, &priv->regs->ctl); - /* Wait transfer to complete */ - ret = wait_for_bit_le32(&priv->regs->ctl, SUN4I_CTL_XCH_MASK, - false, SUN4I_SPI_TIMEOUT_US, false); - if (ret) { + /* Wait till RX FIFO to be empty */ + ret = readl_poll_timeout(&priv->regs->fifo_sta, rx_fifocnt, + (((rx_fifocnt & SUN4I_FIFO_STA_RF_CNT_MASK) >> + SUN4I_FIFO_STA_RF_CNT_BITS) >= nbytes), + SUN4I_SPI_TIMEOUT_US); + if (ret < 0) { printf("ERROR: sun4i_spi: Timeout transferring data\n"); sun4i_spi_set_cs(bus, slave_plat->cs, false); return ret; -- 2.39.5