Please find my comments below:
-Error code 69 refers to a timeout error.
-The CyU3PMipicsiInit() can fail due to the following reasons:
1.If an I2C read/write timeout occurs during the operation (This is the issue that you are facing now).
2.If the part on which this function is called is not a CX3 device.
3.If a general or unknown error occurred during the operation.
The CX3 part uses the I2C block to communicate with both the MIPI-CSI block and any connected Image Sensor. The 7 bit I2C slave address 8b'0000111X (Read 0x0F, Write 0x0E) is used internally by the CX3 part to configure and control the MIPI-CSI interface block and should not be used by any external I2C slaves connected to the CX3 on the I2C bus. Also, the pull-ups for I2C lines are to be provided as per checklists mentioned in AN70707, the link to which is given below: