[U-Boot] [PATCH 2/2] xilinx_xiic: Fix transfer initialisation

[Melin Tomas]

Prior to starting a new transfer, conditionally wait for bus to not
be busy.

Reinitialise controller as otherwise operation is not stable.
For reference, see linux kernel commit: 9656eeebf3f1dd05376c4c923797369746d9a618

Signed-off-by: Tomas Melin <tomas.melin at vaisala.com>
---
 drivers/i2c/xilinx_xiic.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/i2c/xilinx_xiic.c b/drivers/i2c/xilinx_xiic.c
index e4ca0ab936..4c2d0edf48 100644
--- a/drivers/i2c/xilinx_xiic.c
+++ b/drivers/i2c/xilinx_xiic.c
@@ -267,6 +267,15 @@ static void xiic_reinit(struct xilinx_xiic_priv *priv)
 static int xilinx_xiic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
 {
 	int ret = 0;
+	struct xilinx_xiic_priv *priv = dev_get_priv(dev);
+
+	ret = wait_for_bit_8(priv->base + XIIC_SR_REG_OFFSET,
+			     XIIC_SR_BUS_BUSY_MASK, false, 3000, true);
+
+	if (ret)
+		return ret;
+
+	xiic_reinit(priv);
 
 	for (; nmsgs > 0; nmsgs--, msg++) {
 		if (msg->flags & I2C_M_RD)
-- 
2.17.2