NCS 2.7.0 and "requires-ulbpr" for spi-nor

[rw_w]

Hello,

I am currently migrating from NCS 2.6.0 to NCS 2.7.0 on my board with an NRF9160.

During that process I switched to the new hardware model and to sysbuild. As far as I see everything works as expected after the migration with NCS 2.7.0, except for writing to the SPI-NOR-Flash on my board. Reading from the SPI-NOR-Flash works with NCS 2.7.0.

I could narrow the issue down to the the requires_ulbpr setting, which is defined in the device tree for the SPI-NOR on my board:

&spi2 {

    compatible = "nordic,nrf-spim";

    status = "okay";

    cs-gpios = <&gpio0 4 GPIO_ACTIVE_LOW>;

    pinctrl-0 = <&spi2_default>;

    pinctrl-1 = <&spi2_sleep>;

    pinctrl-names = "default", "sleep";

    sst26vf016b: sst26vf016b@0 {

        compatible = "jedec,spi-nor";

        requires-ulbpr;

        reg = <0>;

        spi-max-frequency = <100000000>;

        size = <16777216>;

        has-dpd;

        t-enter-dpd = <3000>;

        t-exit-dpd = <5000>;

        jedec-id = [ bf 26 41 ];

    };

};

It seems in NCS 2.7.0 the setting is not evaluated correctly in spi_nor.c. In this version it is mapped to a bitfield, but the bit does not seem to be set, even if the requires-ulbpr is defined in the device-tree.

If I do the check the same it was done in NCS 2.6.0 instead of using the cfg->requires_ulbpr_exist bit (in function spi_nor_write_protection_set() of spi_nor.c) the setting is recognized correctly and writing is possible:

IS_ENABLED(DT_INST_PROP(0, requires_ulbpr)

Am I missing something? Is the bit field filled automatically or does it now require some initialization call for the SPI driver so it is working correctly?

Best regards

rw

[Kazi Afroza Sultana]

Hello rw,

Can you please try our official sample (Serila_lte_modem) making this change in overlay file () ?

&arduino_spi {
mx25r64: mx25r6435f@1 {
status = "okay";
requires-ulbpr;
};
};

[rw_w]

Hello,

I tried the jesd216 sample  (https://docs.zephyrproject.org/latest/samples/drivers/jesd216/README.html) on the NRF9160 DK with the overlay changes you suggested, as I could not find an easy way to access the NOR-flash in the serial_lte_modem application.

I extended this sample to also perform a write operation and print out the state of cfg->requires_ulbpr_exist.

It was working on the NRF9160 DK and also on my hardware (and devicetree) as expected (the parameter was set).

But if I add CONFIG_SPI_NOR_SFDP_RUNTIME=y to the configuration of the sample (which is also set in my application) cfg->requires_ulbpr_exist is not set on the NRF9160 DK and on my hardware.

So it seems cfg->requires_ulbpr_exist is not initialized if the SFDP parameters of the NOR-FLASH are read out at runtime (with CONFIG_SPI_NOR_SFDP_RUNTIME=y).

Is this behaviour intended?

Best Regards

rw

[Kazi Afroza Sultana]

Hello RW,

In consequence of my last reply (adding the overlay in SLM application);

The overlay in enabled in the built device tree file.

You can continue to check if cfg->requires_ulbpr_exist is set with SLM, when run full modem FOTA.

[rw_w]

Yes, it is enabled in the device tree. That is not the problem.

The problem is that if CONFIG_SPI_NOR_SFDP_RUNTIME=y is used in the prj.conf file cfg->requires_ulbpr_exist is not initialized for spi_nor in NCS 2.7.0.

[Kazi Afroza Sultana]

Can you please explain this "cfg->requires_ulbpr_exist is not initialized"?

[rw_w]

In the spi_nor driver (zephyr/drivers/flash/spi_nor.c) the struct spi_nor_config in v2.7.0 now also contains flags for some device tree opt-ins:

struct spi_nor_config {
    ...
	/* exist flags for dts opt-ins */
	bool dpd_exist:1;
	bool dpd_wakeup_sequence_exist:1;
	bool mxicy_mx25r_power_mode_exist:1;
	bool reset_gpios_exist:1;
	bool requires_ulbpr_exist:1;
	bool wp_gpios_exist:1;
	bool hold_gpios_exist:1;
};

If CONFIG_SPI_NOR_SFDP_RUNTIME=y is not used in the project configuration, requires_ulpbr from the devicetree is evaluated correctly and cfg->requires_ulbpr_exist is set to 1.

If CONFIG_SPI_NOR_SFDP_RUNTIME=y is used in the project configuration, it seems that requires_ulpbr from the devicetree is not evaluated and cfg->requires_ulbpr_exist stays 0.

The reason for that seems to be (line 1678):

#define GENERATE_CONFIG_STRUCT(idx)								\
	static const struct spi_nor_config spi_nor_##idx##_config = {				\
		.spi = SPI_DT_SPEC_INST_GET(idx, SPI_WORD_SET(8), CONFIG_SPI_NOR_CS_WAIT_DELAY),\
		COND_CODE_1(CONFIG_SPI_NOR_SFDP_RUNTIME, EMPTY(), (INST_CONFIG_STRUCT_GEN(idx)))};

So INST_CONFIG_STRUCT_GEN(idx), which would set cfg->requires_ulbpr_exist according to the device tree, is not called if CONFIG_SPI_NOR_SFDP_RUNTIME is used. But there also does not seem to be any other way to provide the information that ulbpr command is required to the spi nor driver at runtime.