i2c: octeon: Add flush writeq helper function

Add helper function that reads back a value after writing to
make sure the write is finished and use it in octeon_i2c_write_int().

Signed-off-by: Peter Swain <[e-mail]>
Signed-off-by: Jan Glauber <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

drivers/i2c/busses/i2c-octeon.c

···
 	struct device *dev;
 };
 
+static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
+{
+	__raw_writeq(val, addr);
+	__raw_readq(addr);	/* wait for write to land */
+}
+
 /**
  * octeon_i2c_reg_write - write an I2C core register
  * @i2c: The struct octeon_i2c
···
  */
 static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
 {
-	__raw_writeq(data, i2c->twsi_base + TWSI_INT);
-	__raw_readq(i2c->twsi_base + TWSI_INT);
+	octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT);
 }
 
 /**