[meta-xilinx] Zynq XADC

[Sören Brinkmann]

On Mon, 2015-05-18 at 11:31AM +0000, MUGRIDGE Robin wrote:
>    Hi,
> 
>     
> 
>    I am having an issue trying to use the Zynq XADC after a linux reboot.  On
>    power up, I can access the XADC in the FSBL.  If I stop the boot in u-boot
>    and issue a reset command, I can still access the XADC from the FSBL. 
>    However, if I let linux start and then issue a reboot command, the XADC no
>    longer works in the FSBL (the XAdcPs_SelfTest function fails – all XADC
>    register reads return 0).
> 
>     
> 
>    I’m using Dizzy.  If it has anything to do with it, I’m not configuring
>    the PL at boot – this is done after linux starts.
> 
>     
> 
>    Is there anything I need to do to allow the XADC to work after linux has
>    been running?

Are you accessing the device through its driver or some other path? The
symptoms sound suspiciously like the device's clock isn't enabled.
Usually the driver is supposed to handle that though. Could you check
the state of the PCAP clock in /sys/kernel/debug/clk/clk_summary?

	Sören