Messages in this thread | | | Date | Tue, 24 Mar 2020 10:24:36 +0100 | From | Horatiu Vultur <> | Subject | Re: [PATCH 6/6] ptp_ocelot: support 4 programmable pins |
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Hi Vladimir,
The 03/20/2020 15:20, Vladimir Oltean wrote: > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > Hi Yangbo, > > On Fri, 20 Mar 2020 at 12:42, Yangbo Lu <yangbo.lu@nxp.com> wrote: > > > > Support 4 programmable pins for only one function periodic > > signal for now. Since the hardware is not able to support > > absolute start time, driver starts periodic signal immediately. > > > > Are you absolutely sure it doesn't support absolute start time? > Because that would mean it's pretty useless if the phase of the PTP > clock signal is out of control.
It looks like there is no support for absolute start time. But you should be able to control the phase using the register PIN_WF_LOW_PERIOD.
> > I tested your patch on the LS1028A-RDB board using the following commands: > > # Select PEROUT function and assign a channel to each of pins > SWITCH_1588_DAT0 and SWITCH_1588_DAT1 > echo '2 0' > /sys/class/ptp/ptp1/pins/switch_1588_dat0 > echo '2 1' > /sys/class/ptp/ptp1/pins/switch_1588_dat1 > # Generate pulses with 1 second period on channel 0 > echo '0 0 0 1 0' > /sys/class/ptp/ptp1/period > # Generate pulses with 1 second period on channel 1 > echo '1 0 0 1 0' > /sys/class/ptp/ptp1/period > > And here is what I get: > https://drive.google.com/open?id=1ErWufJL0TWv6hKDQdF1pRL5gn4hn4X-r > > So the periodic output really starts 'now' just like the print says, > so the output from DAT0 is not even in sync with DAT1. > > > Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> > > --- > > Thanks, > -Vladimir
-- /Horatiu
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