SD card interface, SD2_WP write protect signal usage

[hyobokahn]

Hi.

I'm working on i.MX6 Solo custom board with Yocto 4.1.15-2.1.0 GA release.

I have problem to use external SD memory card on my board.

The device driver cannot not probing SD memory card interface.

I wondering my board SD memory card interface hardware have some different from Sabresd board.

my board use SD2 interface.

i.MX6 manual said, SD2_WP must tied to low, if do not use write protection line.

(page 5602 of "i.MX6 Solo/DualLite Applications Processor Reference Manual, Rev2, 04/2015")

unfortunately, my board floating SD2_WP board now.

I guess, this is make trouble to working of SD memory interface.

My question is

1. if I floating SD2_WP, the SD memory card is not work?

2. is there any way to resolve this problem by software?

    modify device driver or device tree blob.

Thanks.

[jimmychan]

There is different setting in device tree file for CD and WP signals if you use the controller internal CD and WP. So please double check it. I think the easiest way is set the CD and WP as a gpio pins. Then set the cd-gpios and wp-gpios to the corresponding gpio pins in the device tree.

For more information, please read the Linux BSP reference manual (chapter 32.2.3) and the BSP porting guide.

you can download it from here:

http://www.nxp.com/products/microcontrollers-and-processors/arm-based-portfolio/i.mx-applications-pr...