nRF5340 QSPI flash

[Jason]

Hi:

SW: NCS v2.5.0

HW: nRF5340 + flash gd25q256e 

To reduce the power consumption of the QSPI flash, we have two approaches.

1. cut off the QSPI flash's power when the product is in sleep mode (the power can be turned on/off by an LDO)

2. always keep the power of the QSPI flash, and put the flash into deep power down mode when the product is in sleep mode.

unfortunately, both of these two approaches have problems.

for approach 1, when turning on the power again, and initiating the QSPI and XIP again, the XIP doesn't work.

e.g 

 printk("#2Address of %x value %x\n", 0x10000008, *(uint32_t *)0x10000008);

 printk("#2Address of %x value %x\n", 0x10000040, *(uint32_t *)0x10000040);

 the values are wrong. 

for approach 2，

put the QSPI flash into deep power down mode by calling pm_device_action_run(flash_dev, PM_DEVICE_ACTION_SUSPEND);

this works, we can see the power consumption is reduced.

wake up the flash from deep power down mode by calling pm_device_action_run(flash_dev, PM_DEVICE_ACTION_RESUME);

but this function return -EIO, and it is caused by the nrfx_qspi_init return NRFX_ERROR_TIMEOUT.

if we don't put the flash into deep power-down mode, every thing is OK.

below is the QSPI configuration 

&qspi {
	status = "okay";
	pinctrl-0 = <&qspi_default>;
	pinctrl-1 = <&qspi_sleep>;
	pinctrl-names = "default", "sleep";
	gd25q256: gd25q256e@0 {
		compatible = "nordic,qspi-nor";
		reg = <0>;
		/* GD25Q256 supports only pp(cmd 02H) and pp4o(cmd 32H) */
		writeoc = "pp4o";
		/* GD25Q256 supports all readoc options */
		readoc = "read4io";
		sck-frequency = <8000000>;
		jedec-id = [c8 40 19];
		sfdp-bfp = [/*read the sfdp-bfp by jesd216 sample(zephyr\samples\drivers\jesd216)*/
			e5 20 f3 ff  ff ff ff 0f  44 eb 08 6b  08 3b 42 bb
			ee ff ff ff  ff ff 00 ff  ff ff 00 ff  0c 20 0f 52
			10 d8 00 ff  d6 39 a5 fe  83 1f 15 51  ec 62 16 33
			7a 75 7a 75  04 bd d5 5c  00 06 64 00  08 50 00 01
		];
		size = <268435456>;
		has-dpd;
		t-enter-dpd = <40000>;
		t-exit-dpd = <45000>;
		enter-4byte-addr = <0x01>;
		address-size-32;
	};
};

Do you have any ideas on this issue?

Thanks!