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Date:   Sun, 2 Feb 2020 20:08:38 -0800
From:   Richard Cochran <richardcochran@gmail.com>
To:     christopher.s.hall@intel.com
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        tglx@linutronix.de, hpa@zytor.com, mingo@redhat.com,
        x86@kernel.org, jacob.e.keller@intel.com, davem@davemloft.net,
        sean.v.kelley@intel.com
Subject: Re: [Intel PMC TGPIO Driver 0/5] Add support for Intel PMC Time GPIO
 Driver with PHC interface changes to support additional H/W Features
Message-ID: <20200203040838.GA5851@localhost>
References: <20191211214852.26317-1-christopher.s.hall@intel.com>
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On Wed, Dec 11, 2019 at 01:48:47PM -0800, christopher.s.hall@intel.com wrote:
> The ART frequency is not adjustable. In order, to implement output
> adjustments an additional edge-timestamp API is added, as well, as
> a periodic output frequency adjustment API. Togther, these implement
> equivalent functionality to the existing SYS_OFFSET_* and frequency
> adjustment APIs.

I don't see a reason for a custom, new API just for this device.

The TGPIO input clock, the ART, is a free running counter, but you
want to support frequency adjustments.  Use a timecounter cyclecounter
pair.

Let the user dial a periodic output signal in the normal way.

Let the user change the frequency in the normal way, and during this
call, adjust the counter values accordingly.

Thanks,
Richard