PCIE IP on i.MX8MM and i.MX8MP is same, customer can follow PCIE test Application note to do compliance test, if eye diagram failed, they can fine turn corresponding regs below:
iMX8MMRM.pdf
IMX8MPRM.pdf
GEN1:
GEN2:
Related code in kernel
Phy-fsl-imx8-pcie.c (kernel-source\drivers\phy\freescale) 3794 2020/11/4
static int imx8_pcie_phy_init(struct phy *phy)
{
……
/* Configure TX drive level */
writel(0x2d, imx8_phy->base + 0x404);
return 0;
}
Thanks
Lambert