ptp: ocp: Skip I2C flash read when there is no controller.

If an I2C controller isn't present, don't try and read the I2C flash.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ptp/ptp_ocp.c

@@ -228,8 +228,8 @@ static int ptp_ocp_ts_enable(void *priv, bool enable);
  * 3: GPS
  * 4: GPS2 (n/c)
  * 5: MAC
- * 6: SPI IMU (inertial measurement unit)
- * 7: I2C oscillator
+ * 6: N/C
+ * 7: I2C controller
  * 8: HWICAP
  * 9: SPI Flash
  */
@@ -706,6 +706,9 @@ ptp_ocp_get_serial_number(struct ptp_ocp *bp)
 	struct device *dev;
 	int err;
 
+	if (!bp->i2c_ctrl)
+		return;
+
 	dev = device_find_child(&bp->i2c_ctrl->dev, NULL, ptp_ocp_firstchild);
 	if (!dev) {
 		dev_err(&bp->pdev->dev, "Can't find I2C adapter\n");