I have noticed that imx6ull chip PMIC_ON_REQ internal 100k pull-up, but now I need to increase the drive capability of the IO, can I modify its internal pull-up resistance?On my development board, due to the insufficient driving ability of PMIC_ON_REQ signal, after ONOFF shutdown, the PMIC ON REQ still has 1.8-2v voltage, resulting in 3.3 and 5v peripheral voltage still, which is a fake shutdown.
I check the manual and find SW_PAD_CTL_PAD_SNVS_PMIC_ON_REQ SW PAD Control Register can configure the electrical properties of PMIC_ON_REQ as follows:
I tried to change the register value to 0001 1111 0000 1011 1000, i.e. 0x1F0B8, 22k Pull up, I added the address of the register on the uboot source code, changed the register to Ox1FOB8, in the kernel part, I wrote the character device driver to set the register to Ox1FOB8, So that after uboot boot and kernel boot, the value of the register is Ox1FOB8.
However, I found that PMIC_ON_REQ still has 1.8-2v voltage after shutdown, I only modified the SW_PAD register because I did not know the clock of the signal, and it did not have the multiplexing register, the I/O mode register, the level configuration register.
I think PMIC_ON_REQ's pin clock is turned on by default. Is this correct? Do I only need to modify the SW_PAD register to configure the electrical properties of PMIC_ON_REQ to achieve 22k pull-up?
Wish you all the best.
