On 05/12/2018 16:27, Keith Squier wrote:
Hannes,
I was thinking that it could be a driver issue. I never thought about
the device tree, but it could be that. At this point, I'm not ruling
anything out. I'm not familiar with device trees or the imx6 hardware.
(I was given this hardware and told to set up the PTP services.)
Please forgive my ignorance. I do have the yocto project to build the
kernel image for this hardware. How would I go about checking that the
device tree is set up correctly? Does the imx6 Hardware Development
Guide talk about setting up the device tree?
To be more specific it depends on how the ethernet PHY is connected to
the imx6 if a separate clock reference is required to clock the 1588
timer and therefore if you need to configure this in the device-tree.
The imx6 has a kind of confusing documentation regarding the
ethernet/PTP clock source. Someone has already written a good summary
about this on the linux mailinglist:
http://lists.infradead.org/pipermail/linux-arm-kernel/2013-September/201066.html
If you have Gigabit Ethernet on your board then you probably use RGMII.
In that case check that the reference clock is enabled on the GPIO_16
pad in the device-tree like this for example:
MX6QDL_PAD_GPIO_16__ENET_REF_CLK 0x4001b0a8
If there is no external clock source on pad GPIO_16 (from the PHY for
example) also the imx6 register GPR1[21] = 1 must be set to loop back
the internal clock to GPIO_16. This can either be done in the bootloader
(u-boot) or you can add it to the fec driver.
Hannes
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