On Sat, 9 Feb 2019 18:44:51 +0530 Jagan Teki jagan@amarulasolutions.com wrote:
Hi,
To drain rx fifo the fifo need to poll till the fifo count become empty.
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 draining fifo.
So, add code for polling fifo status register till rxfifo count become empty.
Signed-off-by: Jagan Teki jagan@amarulasolutions.com
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..87b396a96e 100644 --- a/drivers/spi/sun4i_spi.c +++ b/drivers/spi/sun4i_spi.c @@ -31,6 +31,8 @@
#include <asm/arch/clock.h>
+#include <linux/iopoll.h>
#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->ctl, rx_fifocnt,
That's not the right register, it should be regs->fifo_sta.
!(((rx_fifocnt & SUN4I_FIFO_STA_RF_CNT_MASK) >>SUN4I_FIFO_STA_RF_CNT_BITS) < nbytes),
I think removing the negation and using ">=" instead is less confusing.
Cheers, Andre.
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;