Handling multiple slaves on single spi master channel

[Ubaid_M]

Hi, 

The spi_config structure zephyr provides is as below:

	struct spi_config
	{
		uint32_t frequency;
		uint16_t operation;
		uint16_t slave;

		const struct spi_cs_control *cs;
	};

Wherein cs is initialized to the chip select pin.

In my project I have a requirement to handle 2 slaves which are exactly the same.

Herein, how can I manage 2 instances of, same slaves

And do I need to get multiple device bindings for the same spi channel..?

Thanks,

Ubaid

[Simonr]

Hi

For SPI devices, "@0 or @1" refers to the position of the chip select pin in the cs-gpios configuration. As you can see in the config below from the Thingy91.dts file, the SPI devices are defined to use one CS pin each.

&spi3 {
	compatible = "nordic,nrf-spim";
	status = "okay";
	sck-pin = <3>;
	mosi-pin = <4>;
	miso-pin = <5>;
	cs-gpios = <&gpio0 8 GPIO_ACTIVE_LOW>, <&gpio0 7 GPIO_ACTIVE_LOW>;

	adxl362@0 {
		compatible = "adi,adxl362";
		label = "ADXL362";
		spi-max-frequency = <8000000>;
		reg = <0>;
		int1-gpios = <&gpio0 9 0>;
	};

	adxl372@1 {
		compatible = "adi,adxl372";
		label = "ADXL372";
		spi-max-frequency = <8000000>;
		reg = <1>;
		int1-gpios = <&gpio0 6 0>;
	};
};

Best regards,

Simon

[Ubaid_M]

Hello Simonr,

Thank you for the info,
Noted on the dts syntax for multiple slaves.

Kindly suggest how this can be handled in code, if i want to call "SPI_Write()" on:

1. slave one <&gpio0 8 GPIO_ACTIVE_LOW>

2. slave two <&gpio0 7 GPIO_ACTIVE_LOW>

What would the code syntax look like..?

How would I configure spi_config..?

and how would I call  "SPI_Write()" on each slave.

Thanks,