QSPI and NRF52840 Communication

[xuezhi_zed]

I am using visual code studio, zephyr RTOS, v2.5.2  on NRF52840 

I am trying to find a QSPI example

I noticed someone mentioned the sample :spi_flash is using QSPI ?  But it does not have an overlay file, is there any other sample code available, for using flash_write/read/erase ?

[Kazi Afroza Sultana]

Hello,

You have to add an overlay if you want to add external flash. There is a previous case where it showed how to do this with JEDEC sample

(+) Add a new JEDEC flash memory device on QSPI - Nordic Q&A - Nordic DevZone - Nordic DevZone (nordicsemi.com)

This is the default QSPI in devicetree of nrf52840dk. 

&qspi {
	status = "okay";
	pinctrl-0 = <&qspi_default>;
	pinctrl-1 = <&qspi_sleep>;
	pinctrl-names = "default", "sleep";
	mx25r64: mx25r6435f@0 {
		compatible = "nordic,qspi-nor";
		reg = <0>;
		/* MX25R64 supports only pp and pp4io */
		writeoc = "pp4io";
		/* MX25R64 supports all readoc options */
		readoc = "read4io";
		sck-frequency = <8000000>;
		jedec-id = [c2 28 17];
		sfdp-bfp = [
			e5 20 f1 ff  ff ff ff 03  44 eb 08 6b  08 3b 04 bb
			ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
			10 d8 00 ff  23 72 f5 00  82 ed 04 cc  44 83 68 44
			30 b0 30 b0  f7 c4 d5 5c  00 be 29 ff  f0 d0 ff ff
		];
		size = <67108864>;
		has-dpd;
		t-enter-dpd = <10000>;
		t-exit-dpd = <35000>;
	};
};

In littlefs sample sdk-zephyr/samples/subsys/fs/littlefs/boards/nrf52840dk_nrf52840.overlay at 49cb90cb0932808759fbbd5c3bf7834d5a0d4ff6 · nrfconnect/sdk-zephyr · GitHub the built-in external flash is used. When you need to use different flash, you can disable the MX25R64 on the overlay.

[xuezhi_zed]

I am testing on a w25m02g ,which is a NAND memory, so I think the littlefs is not really helpful. 

Can I get clarifications :  flash_read/write/erase are QSPI functions , support 4 IO lines while spi_read/write only support SPI communications but not QSPI? 

[xuezhi_zed]

or is there any example named qspi_read/write? 

I saw someone mentioned this https://docs.nordicsemi.com/bundle/ncs-2.3.0/page/zephyr/samples/drivers/jesd216/README.html

but not sure how to find the code of this sample?