From: Wojciech Zmuda wzmuda@n7space.com
Hello Jan, hello all,
Sorry for not keeping up with the list recently. I had plans to deliver working Coresight support for Zynq Ultrascale+, but it looks like I won't be able to dedicate a proper time slice for that in the nearest future.
I guess, the best solution for everybody would be to share what I've got so far.
A few notes first: 1. I'm successfully using this configuration on Xilinx ZCU104 board running mainline Linux 5.1-rc1 with some Linaro patches applied. Since I can see those patches have already made it into mainline, I think this DTS should work, with a minor tweaks, the on current mainline. 2. Since I forked Linux, bindings for funnel and replicator has changed. The ones used here are obsolete now. I think they should still work, but warnings will be issued in dmesg. New bindings are described in Documentation/devicetree/bindings/arm/coresight.txt in Linux tree. 3. I'm successfully tracing with all four ETMs to both ETFs and ETR. This suggests ETM, ETF and ETR bindings as well as replicators and funnels bindings should be correct. 4. However, I haven't tested the TPIU port or STM. While the description seems accurate with the Zynq US+ TRM, I cannot confirm it is complete. 5. Platform specific: for timestamp support, the timestamp generator must be enabled. It can be done from uBoot with the following command:
ZynqMP> mw fe900000 1
Not doing this will cause Perf to report 'Timestamp: 0x0' when the 'timestamp' flag is added to cs_etm event. This is described in details somewhere on this list.
6. I based the DTS file on what I've found here: https://gitlab.fel.cvut.cz/barysmax/diploma-sw-hw-xilinx/ The DTS patch stored in this repo didn't work out of the box, but gave me a starting point.
Many thanks for the Linaro team, who offered me a great help on enabling and testing Coresight on this SoC. I'll try to monitor Zynq-related threads on the list and to offer my help.
Wojciech Zmuda (1): zynqmp: Add CoreSight support to DTS
.../boot/dts/xilinx/zynqmp-coresight.dtsi | 312 ++++++++++++++++++ .../boot/dts/xilinx/zynqmp-zcu104-revA.dts | 1 + 2 files changed, 313 insertions(+) create mode 100644 arch/arm64/boot/dts/xilinx/zynqmp-coresight.dtsi