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Date:   Fri, 19 Jul 2019 15:20:21 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Felipe Balbi <felipe.balbi@linux.intel.com>
Cc:     Richard Cochran <richardcochran@gmail.com>, netdev@vger.kernel.org,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org,
        "Christopher S . Hall" <christopher.s.hall@intel.com>
Subject: Re: [RFC PATCH 0/5] PTP: add support for Intel's TGPIO controller
Message-ID: <20190719132021.GC24930@lunn.ch>
References: <20190716072038.8408-1-felipe.balbi@linux.intel.com>
 <20190718195040.GL25635@lunn.ch>
 <87h87isci5.fsf@linux.intel.com>
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On Fri, Jul 19, 2019 at 10:35:14AM +0300, Felipe Balbi wrote:
> 
> Hi,
> 
> Andrew Lunn <andrew@lunn.ch> writes:
> > On Tue, Jul 16, 2019 at 10:20:33AM +0300, Felipe Balbi wrote:
> >> TGPIO is a new IP which allows for time synchronization between systems
> >> without any other means of synchronization such as PTP or NTP. The
> >> driver is implemented as part of the PTP framework since its features
> >> covered most of what this controller can do.
> >
> > Hi Felipe
> >
> > Given the name TGPIO, can it also be used for plain old boring GPIO?
> 
> not really, no. This is a misnomer, IMHO :-) We can only assert output
> pulses at specified intervals or capture a timestamp of an external
> signal.

Hi Felipe

So i guess Intel Marketing wants to call it a GPIO, but between
engineers can we give it a better name?

> > Also, is this always embedded into a SoC? Or could it actually be in a
> > discrete NIC?
> 
> Technically, this could be done as a discrete, but it isn't. In any
> case, why does that matter? From a linux-point of view, we have a device
> driver either way.

I've seen a lot of i210 used with ARM SoCs. How necessary is the tsc
patch? Is there an architecture independent alternative?

       Andrew