topic Re: How do disable pull-down in SCU_GPIO0_00 in SCU in i.MX Processors

How do disable pull-down in SCU_GPIO0_00 in SCU

Maddis — Wed, 29 Apr 2020 10:56:12 GMT

Hi,

In our i.MX8QX HW we have pull-up on SCU_GPIO0_00 - pin and by default it has pull-down resulting non-ideal state until system reached either U-boot or Linux.

I tried to disable the pull-down in SCU firmware with command:

(void) sc_pad_set_gp(pt_sc, SC_P_SCU_GPIO0_00, 0x00000060);

Called from function : void board_config_sc(sc_rm_pt_t pt_sc)

But it did nothing. We release that pin in SCU firmware (or make it 'movable' as it's called there) so I already know that the SCU modifications will go through in use.

I tried different values for the last one, but none of them didn't seem to work and couldn't really find examples/better documentation.

Is that even correct function call and what control value I should use?

Re: How do disable pull-down in SCU_GPIO0_00 in SCU

igorpadykov — Wed, 29 Apr 2020 11:37:08 GMT

Hi mc

also one can look at pads initialization examples in ../mx8qx_mek/board.c file

function pmic_init() and ...svc/pad/svc.h

SCFW Porting Kit

Best regards
igor
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

Re: How do disable pull-down in SCU_GPIO0_00 in SCU

Maddis — Thu, 30 Apr 2020 04:48:02 GMT

I looked at the function mentioned. Seems it's using function: sc_pad_set_gp_28fdsoi so I changed my call to sc_pad_set_gp_28fdsoi(pt_sc, SC_P_SCU_GPIO0_00, SC_PAD_28FDSOI_DSE_18V_1MA, SC_PAD_28FDSOI_PS_NONE);

Didn't work. Obviously there is something I'm doing wrong, but I have no idea what. Luckily this is not critical issue, but it'd be good to get working properly.

Re: How do disable pull-down in SCU_GPIO0_00 in SCU

igorpadykov — Thu, 30 Apr 2020 05:45:31 GMT

try without "sc_", there is call in pmic_init() :

pad_set_gp_28fdsoi(SC_PT, SC_P_PMIC_I2C_SDA, SC_PAD_28FDSOI_DSE_18V_1MA, SC_PAD_28FDSOI_PS_PU);

one can check if it works on i.MX8QXP MEK board with Demo Image

Linux Binary Demo Files - i.MX 8QXPlus MEK

Best regards
igor