Date: Tue, 24 Jan 2023 15:43:52 +0000 From: "Dr. Rolf Jansen" <freebsd-rj@cyclaero.com> To: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: GPIO inputs on Pis? Message-ID: <01070185e4732fd8-c0bede0b-d9df-4557-a174-cb237fa4bfaf-000000@eu-central-1.amazonses.com> In-Reply-To: <a9b00748-1a11-3806-1103-ac2e6ad6bf43@denninger.net> References: <0b235f83-7cb3-1d14-7c64-aee7c1c0c23d@denninger.net> <01070185e46b1a6e-ee34b885-1215-45c7-ac18-83320c02cac2-000000@eu-central-1.amazonses.com> <a9b00748-1a11-3806-1103-ac2e6ad6bf43@denninger.net>
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--Apple-Mail=_C69401B8-1DDE-4319-AE6A-B62FC4FF9828 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii I sent an old ink to the thread on the mailing list, which does not work = anymore. Here ist the new link: = https://lists.freebsd.org/pipermail/freebsd-arm/2020-November/022738.html = <https://lists.freebsd.org/pipermail/freebsd-arm/2020-November/022738.html= > > Am 24.01.2023 um 12:35 schrieb Karl Denninger <karl@denninger.net = <mailto:karl@denninger.net>>: >=20 > Thank you -- will check it out. >=20 > On 1/24/2023 10:35, Dr. Rolf Jansen wrote: >>> Am 23.01.2023 um 11:41 schrieb Karl Denninger <karl@denninger.net = <mailto:karl@denninger.net>>: >>>=20 >>> Is there support somewhere in the 13.x for other than "read current = state" / "set current state"? >>>=20 >>> Specifically, there is evidence in the sys/gpio.h header file that I = can open up a file descriptor and then use select()/read() to grab the = contents of a ring buffer of some size (presumably interrupt-posted) of = events since last look, and determine if there's anything in there. = Provided you're reasonably fast this might be enough to, for example, = read an optical encoder that has a modest pulse rate. >>>=20 >>> I see apparent review code at https://reviews.freebsd.org/D27398 = <https://reviews.freebsd.org/D27398>; from late 2020, but nothing else I = can find digging around; an example (assuming it is actually implemented = and works) would be helpful >>>=20 >> See >>=20 >> = https://forums.freebsd.org/threads/gpio-api-general-orange-pi-h3.83950/pos= t-556728 = <https://forums.freebsd.org/threads/gpio-api-general-orange-pi-h3.83950/po= st-556728> >>=20 >> And the messages in that thread that follow the one linked above. >>=20 >> There is a respective thread on this mailing list as well: >>=20 >> Porting FreeBSD to ARM processors: User Space GPIO Interrupt = programming - GSoC-2018 = <https://lists.freebsd.org/archives/freebsd-arm/2020-November/022740.html>= --=20 > Karl Denninger > karl@denninger.net <mailto:karl@denninger.net> > The Market Ticker > [S/MIME encrypted email preferred] --Apple-Mail=_C69401B8-1DDE-4319-AE6A-B62FC4FF9828 Content-Transfer-Encoding: 7bit Content-Type: text/html; charset=us-ascii <html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><meta http-equiv="Content-Type" content="text/html; charset=us-ascii" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I sent an old ink to the thread on the mailing list, which does not work anymore. Here ist the new link:<div class=""><br class=""></div><div class=""><a href="https://lists.freebsd.org/pipermail/freebsd-arm/2020-November/022738.html" class="">https://lists.freebsd.org/pipermail/freebsd-arm/2020-November/022738.html</a></div><div class=""><br class=""></div><div class=""><div class=""><blockquote type="cite" class=""><div class="">Am 24.01.2023 um 12:35 schrieb Karl Denninger <<a href="mailto:karl@denninger.net" class="">karl@denninger.net</a>>:</div><br class="Apple-interchange-newline"><div class=""> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" class=""> <div class=""><p class="">Thank you -- will check it out.<br class=""> </p> <div class="moz-cite-prefix">On 1/24/2023 10:35, Dr. Rolf Jansen wrote:<br class=""> </div> <blockquote type="cite" cite="mid:01070185e46b1a6e-ee34b885-1215-45c7-ac18-83320c02cac2-000000@eu-central-1.amazonses.com" class=""> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" class=""> <div class=""> <blockquote type="cite" class=""> <div class="">Am 23.01.2023 um 11:41 schrieb Karl Denninger <<a href="mailto:karl@denninger.net" class="moz-txt-link-freetext" moz-do-not-send="true">karl@denninger.net</a>>:</div> <br class="Apple-interchange-newline"> <div class=""> <meta http-equiv="content-type" content="text/html; charset=UTF-8" class=""> <div class=""><p class="">Is there support somewhere in the 13.x for other than "read current state" / "set current state"?</p><p class="">Specifically, there is evidence in the sys/gpio.h header file that I can open up a file descriptor and then use select()/read() to grab the contents of a ring buffer of some size (presumably interrupt-posted) of events since last look, and determine if there's anything in there. Provided you're reasonably fast this might be enough to, for example, read an optical encoder that has a modest pulse rate.</p><p class="">I see apparent review code at <a class="moz-txt-link-freetext" href="https://reviews.freebsd.org/D27398" moz-do-not-send="true">https://reviews.freebsd.org/D27398</a>; from late 2020, but nothing else I can find digging around; an example (assuming it is actually implemented and works) would be helpful</p> </div> </div> </blockquote> </div> See <div class=""><br class=""> </div> <div class=""><a href="https://forums.freebsd.org/threads/gpio-api-general-orange-pi-h3.83950/post-556728" class="moz-txt-link-freetext" moz-do-not-send="true">https://forums.freebsd.org/threads/gpio-api-general-orange-pi-h3.83950/post-556728</a></div>; <div class=""><br class=""> </div> <div class="">And the messages in that thread that follow the one linked above.</div> <div class=""><br class=""> </div> <div class="">There is a respective thread on this mailing list as well:</div> <div class=""><br class=""> </div> <div class=""><a href="https://lists.freebsd.org/archives/freebsd-arm/2020-November/022740.html" class="" moz-do-not-send="true">Porting FreeBSD to ARM processors: User Space GPIO Interrupt programming - GSoC-2018</a></div> </blockquote> <div class="moz-signature">-- <br class=""> Karl Denninger<br class=""> <a href="mailto:karl@denninger.net" class="moz-txt-link-freetext">karl@denninger.net</a><br class=""> <i class="">The Market Ticker</i><br class=""> <font size="-2" class=""><i class="">[S/MIME encrypted email preferred]</i></font></div> </div> </div></blockquote></div><br class=""></div></div></body></html> --Apple-Mail=_C69401B8-1DDE-4319-AE6A-B62FC4FF9828--
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