How to use the SPI CS signal as the GPIO?

[temp4eb]

Due to the shortage of the pin, I used GPIO5 of ESP32 to be multiplexed as the CS of SPI and the normal GPIO for outputting a control signal. The control signal is simply pulled up or pulled low. In actual use, I found that the CS signal is system internal management .As a normal GPIO signal output, this GPIO should be initialized. But once the GPIO initialization, it can NOT access the SPI device any more, even if the CS signal is high, it seems the GPIO initialization will affect the SPI access, how to solve this problem? Or are there some mechanism to deinit the GPIO and release the managment to SPI?Thanx!