Set Device Pointer to NULL

[RadicalTomato]

struct spi_cs_control {
	/**
	 * GPIO devicetree specification of CS GPIO.
	 * The device pointer can be set to NULL to fully inhibit CS control if
	 * necessary. The GPIO flags GPIO_ACTIVE_LOW/GPIO_ACTIVE_HIGH should be
	 * equivalent to SPI_CS_ACTIVE_HIGH/SPI_CS_ACTIVE_LOW options in struct
	 * spi_config.
	 */
	struct gpio_dt_spec gpio;
	/**
	 * Delay in microseconds to wait before starting the
	 * transmission and before releasing the CS line.
	 */
	uint32_t delay;
};

In my application I would like to inhibit the CS control. How can this be achieved? Is this done at Device Tree level? 

Can it be done in the code, in the lines of:

memset(&spi.config.cs, NULL, sizeof(spi.config.cs));

[Naeem Maroof]

Hello,

Thank you for contacting DevZone at NordicSemi.

The spi_config struct contains the spi_cs_control struct.

So essentially you can set it in the spi configuration that you will use for the spi istance.

[RadicalTomato]

Please provide the recommended way of setting this structure to NULL. 

If using this:

I am getting the following build error:

 error: incompatible types when assigning to type 'struct spi_cs_control' from type 'void *'
   66 |         spi.config.cs = NULL;
      |                         ^~~~

the SDK is v2.5.0. 

Previously the same code has been based on SDK v2.4.0 and it was building fine. Looks like there is breaking change when switching from 2.4.0 to 2.5.0 for the SPI driver. 

Going into the driver header files, the change becomes obvious so yes, the build error makes sense, as there is no pointer in the struct anymore, but another struct.

Hmmm ... looks like the changes are coming from here:

Zephyr 3.4.0 — Zephyr Project documentation (nRF Connect SDK) (nordicsemi.com)

[Naeem Maroof]

Yes, in NCS 2.5.0 (tagged with zephyr 3.4.0), the cs is a member of type cpi_cs_control within spi_config

but in NCS 2.4.0 (tagged with zephyr 3.3.0) the cs is a pointer to spi_cs_control within spi_config