Messages in this thread | | | From | "N, Pandith" <> | Subject | RE: Intel timed i/o driver in HTE | Date | Fri, 2 Dec 2022 03:00:29 +0000 |
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> -----Original Message----- > From: Dipen Patel <dipenp@nvidia.com> > Sent: Wednesday, November 30, 2022 8:54 AM > To: Linus Walleij <linus.walleij@linaro.org>; N, Pandith > <pandith.n@intel.com> > Cc: linux-kernel@vger.kernel.org; Hall, Christopher S > <christopher.s.hall@intel.com>; Gross, Mark <mark.gross@intel.com>; > Sangannavar, Mallikarjunappa <mallikarjunappa.sangannavar@intel.com>; > D, Lakshmi Sowjanya <lakshmi.sowjanya.d@intel.com>; T R, Thejesh Reddy > <thejesh.reddy.t.r@intel.com>; andriy.shevchenko@linux.intel.com; > timestamp@lists.linux.dev > Subject: Re: Intel timed i/o driver in HTE > > On 11/23/22 1:22 PM, Linus Walleij wrote: > > On Wed, Nov 23, 2022 at 3:38 PM N, Pandith <pandith.n@intel.com> > wrote: > > > >> Since the current gpio framework is inadequate to periodic output > modes. > >> I thought to disentangle from gpio and develop a new hte consumer. > >> Something like hte-libcdev.c > > > > Maybe, if Dipen wants it. > > Or maybe it needs its own subsystem. > > Or maybe it should be with whatever is using these pulse trains. > > > Few things I want to know from Pandith as below: > 1. Does timed io only meant for GPIO or other signals? if other signals, what > type of signals? This could be time sync signals or periodic/single pulse input for timestamp support
> 2. In the output mode case where for example, timed io IP outputs 1ms GPIO > pulse, does it also timestamp it for consumers to retrieve later? No. In output mode, either single shot or periodic pulse train is generated. But timed i/o does keep timestamp data in input mode.
> 3. Can you share rough idea you have in mind for the hte-libcdev? a. This layer can provide ioctl based user interactions for timestamp services (input and output mode) b. char device creation for timestamping hardware. Something like /dev/hteX c. Develop a native hte consumer, which handles user space interactions of hte subsystem > > > Again: what is it used for? If we have no idea what it is supposed to > > be used for, we cannot place it right, even less test it. > I think it can possibly act as time sync server as one of the use case. > > > > Yours, > > Linus Walleij
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