STM32 ospi support for Dual Hyperram/Flash

[SongFish2135]

I am trying to implement a multiplexed octospi design using a STM32U575 interfaced with a Flash + HYPERRAM module as shown here taken from the AN5050 STM32 Application Note:

However, when attempting to add the devices to the device tree, it returns a __device_dts_ord error whose device number corresponds to the HYPERRAM instantiation. The device is generated in the devicetree_generated.h file but does not seemed to be in zephyr_pre0.map. The .dts file instantiation looks like:

&octospi2 {
	pinctrl-0 = <&octospi_pins>;
	pinctrl-names = "default";
	status="okay";

	flash: ospi-nor-flash@0 {
		compatible = "st,stm32-ospi-nor";
		reg = <0>;
		size = <DT_SIZE_M(512)>;
		ospi-max-frequency = <DT_FREQ_M(50)>;
		spi-bus-width = <OSPI_OPI_MODE>;
		data-rate = <OSPI_STR_TRANSFER>;
		status = "okay";
	};

	hram: ospi-nor-flash@1 {
		compatible = "st,stm32-ospi-nor";
		reg = <1>;
		size = <DT_SIZE_M(512)>;
		ospi-max-frequency = <DT_FREQ_M(50)>;
		spi-bus-width = <OSPI_OPI_MODE>;
		data-rate = <OSPI_DTR_TRANSFER>;
		status = "okay";
	};


};

The flash and HYPERRAM instantiations both work individually under the &octospi2 device, but fail when they are both defined. I have tried changing compatible types, frequencies, reg values, bus widths, data rates, and pinctrl-0 pins, but it still fails. Is this kind of device definition not possible in Zephyr or am I defining it incorrectly?

[mariopaja]

Hi @SongFish2135,

I dont know how pinctrl-0 = <&octospi_pins> looks like but I think that is your issue.

I think you are trying to connect two devices in OSPI_OPI_MODE simultaneously on the same ospi node.
Why dont you connect the second device on &octospi1?

BTW do you have a custom HYPERRAM driver? As I know, at the moment there is no support for stm32_ospi_hyperram.

[SongFish2135]

I have also tried the following setup which resulted in the same error:

&octospi2 {
	pinctrl-0 = <&octospi2_pins>;
	pinctrl-names = "default";
	status="okay";

	flash: ospi-nor-flash@0 {
		compatible = "st,stm32-ospi-nor";
		reg = <0>;
		size = <DT_SIZE_M(512)>;
		ospi-max-frequency = <DT_FREQ_M(50)>;
		spi-bus-width = <OSPI_OPI_MODE>;
		data-rate = <OSPI_STR_TRANSFER>;
		status = "okay";
	};
};

&octospi1 {
    pinctrl-0 = <&octospi1_pins>;
	pinctrl-names = "default";
	status="okay";

	hram: ospi-nor-flash@1 {
		compatible = "st,stm32-ospi-nor";
		reg = <1>;
		size = <DT_SIZE_M(512)>;
		ospi-max-frequency = <DT_FREQ_M(50)>;
		spi-bus-width = <OSPI_OPI_MODE>;
		data-rate = <OSPI_DTR_TRANSFER>;
		status = "okay";
	};

};

The only difference between octospi2_pins and octospi1_pins is that octospi1_pins includes an octospim_p1_ncs pin while octospi2_pins includes an octospim_p2_ncs pin. They both share the same octospim_p2_clk, octospim_p2_dqs, and octospi_p2_io0 - octospi_p2_io7 gpio pins as to coincide with the configuration from the STM32 application note. The octospi2 IO, CLK, and DQS pins must be shared between both devices because the octospi1 IO pins are occupied by other peripherals. I am also currently working on a custom HYPERRAM driver and temporarily disabling the flash device to test the octospi - HYPERRAM interface.