I'm debugging 1588 issues on our imx6solo (P/N: MCIMX6S5EVM10AC) system. RGMII is used on our system. I have configures GPIO_16 as MX6QDL_PAD_GPIO_16__ENET_REF_CLK signal based on the thread from https://community.nxp.com/thread/326497 .
The strange thing is that the GPIO_16 pin will output 50MHz clock after eth0 up. If use "ifconfig eth0 down" command, the 50MHz clock output will disappear. I use "memtool" tool to check the register (IOMUXC_SW_MUX_CTL_PAD_GPIO16, address 0x020E0214), the values is 0x02, for ENET_REF_CLK.
if (IOMUXC_SW_MUX_CTL_PAD_GPIO16, address 0x020E0214) is changed other value except 0x02, there is no the 50MHz clock output from the GPIO_16 PIN when eth0 up.
I can't provide refer clock on GPIO_16 pin because it will conflict with the 50MHz output. If there is no extern reference clock, the 1588 can't work. How to fix this issue? Thanks.