On 07/08/2024 14:51, Francesco Dolcini wrote:
Hello Frank,
+Rafael
On Wed, Aug 07, 2024 at 11:34:48AM -0400, Frank Li wrote:
On Wed, Aug 07, 2024 at 04:43:49PM +0200, Francesco Dolcini wrote:
From: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
On i.MX8 the FEC PPS channel is routed to the instance 1, not to the
default 0.
According to my understand, it should be board level configuration. FEC
support output pps to any one. choose which one by board design.
This seems different from the information we got from NXP some time ago,
unfortunately this was happening over some private email exchange and
not documented anywhere public. But the message was about SoC internal
routing, not something at the board level, at least for i.MX8 SoCs that
is what this patch is changing.
For example to use PPS on i.MX8QXP we need to have this
IMX8QM_ENET0_REFCLK_125M_25M_CONN_ENET0_PPS 0x06000020
pinctrl configuration _and_ use PPS channel 1. Same is for i.MX8QP.
Maybe Rafael can provide you some more details and the name of the
person that provided this information.
And maybe you can also try to double check this internally within NXP.
Depending on what we find out we can decide if this patch needs to be
dropped or not.
Francesco
Hello Frank,
We have received the information from NXP support that the iMX8X only
supports channel 1. Here's the link of the public question I asked:
https://community.nxp.com/t5/i-MX-Processors/IMX8X-PPS-output-configuration/m-p/1552154
Unfortunately, the response came directly to my e-mail address with no
public update, but you can probably check the internal support case
number 00500877.
Here's an excerpt from the response:
I have checked this issue from soc level, the pps signal is routed to
the 1588_timer1, not routed to 1588_timer0( being used in code default).
At the time, I asked a followup question:
Can I assume that IMX8QM_ENET0_REFCLK_125M_25M_CONN_ENET1_PPS is connected to
1588_timer3 then?
To which I got the reply:
No, ENET1_PPS is also routed through timer1. One can't use ENET0_PPS and
ENET1_PPS at a same time because of same routing path.
I also asked for confirmation if this behavior was the same on the
iMX8Q, which I didn't get. However, we had another customer also
reporting problems getting the PPS output to work on our Apalis iMX8QM
module, and in this case, the change to channel 1 also made it work.
This leads me to believe that the iMX8X and iMX8Q are behaving the same
way in this regard.
We would really appreciate some clarification if we got some of the
details wrong.
Rafael
