From owner-freebsd-arm@freebsd.org Sun Aug 12 04:01:25 2018 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 9E3A110627D0 for ; Sun, 12 Aug 2018 04:01:25 +0000 (UTC) (envelope-from rj@obsigna.com) Received: from mail.cyclaero.de (ec2-18-195-62-44.eu-central-1.compute.amazonaws.com [18.195.62.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4144D76B16 for ; Sun, 12 Aug 2018 04:01:24 +0000 (UTC) (envelope-from rj@obsigna.com) Received: from mail.obsigna.com (unknown [191.182.171.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.cyclaero.de (Postfix) with ESMTPSA id 5333493 for ; Sun, 12 Aug 2018 06:01:23 +0200 (CEST) Received: from rolf.projectworld.net (rolf.projectworld.net [192.168.222.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.obsigna.com (Postfix) with ESMTPSA id 2BA011350F91D for ; Sun, 12 Aug 2018 01:01:19 -0300 (BRT) From: "Dr. Rolf Jansen" Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: BeagleBone Black with a I2C Digital Analog Converter Date: Sun, 12 Aug 2018 01:01:18 -0300 References: <3C191052-1E2C-4D85-8CF1-AAC64F0500B7@obsigna.com> <1533743140.9860.99.camel@freebsd.org> <3007D25E-4884-4652-8B0D-9C6A837D4ADB@obsigna.com> <1534020139.31375.16.camel@freebsd.org> To: freebsd-arm@FreeBSD.org In-Reply-To: <1534020139.31375.16.camel@freebsd.org> Message-Id: <74831EA5-1BBD-442A-BD24-6DE1FDBBD575@obsigna.com> X-Mailer: Apple Mail (2.3445.9.1) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Aug 2018 04:01:25 -0000 > Am 11.08.2018 um 17:42 schrieb Ian Lepore : >=20 > On Sat, 2018-08-11 at 17:30 -0300, Dr. Rolf Jansen wrote: >>>=20 >>> ... >>> , anyway I am >>> stuck at this point. >>=20 >> I got it working. >>=20 >> 1.) The specification of the DAC board which I attached to my BBB was >> wrong in regards to the acceptable Vcc voltage range (2.7 to 5.5 V). >> ...=20 >>=20 >> 2. There is still something wrong with my overlay. I need to hack in >> the same I2C1 changes into the main DT, and then the bus scan by i2c >> -f /dev/iic1 -s gives me the expected output. For my present project >> this is a minor issue, though. My best guess here is, that there is a >> problem with the reference of the I2C1 node to the proposed pinmux >> node. >>=20 >> On Debian/Linux the very overlay does work. >>=20 >=20 > Ah. The board probably does support 2.7-5.5v, but if the i2c bus has > pullups that only pull the lines up to 3.3v, that may be too close to > the VIH transition levels for the DAC chip running at 5v. Even if it's > within the VIH range, if the pulls aren't strong enough the clock > signal may not rise above the 5v VIH fast enough for reliable comms. I was too happy too soon. Now, I updated my system to the 12 snapshot from yesterday, which turned = it from 12-CURRENT to 12-ALPHA1, and with that one, the issue number 2 = above turned from a minor issue to a major problem, in order not to say = a whole new barrier is now blocking all my further efforts. It seems = that in 12-ALPHA1 the DTB is statically compiled into the kernel, and = now I cannot simply hack-in anymore some nodes which don't work by the = way of overlays OK, in the moment I may switch back to 12-CURRENT, however, I am = elaborating this project with 12 now, so I won't have any headaches in = the future. Now I am stuck again. Please may I ask for an advice? May I expect that pinmuxing will work in a not too distant future with = overlays? Am I really supposed to build a custom kernel, only for getting 2 pins = straight? Building a kernel takes forever on the BBB. Shall, I forget 12 and stay with 11 for the next years? BTW: The startup script /etc/rc.d/ntpd got a flaw. The -p option must be = removed from the cmdargs. Best regards Rolf