Date: Tue, 27 Apr 2021 14:11:03 +0200 From: Emmanuel Vadot <manu@bidouilliste.com> To: Mark Murray <markm@FreeBSD.org> Cc: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: I2C/IIC working on RPI4 8GB? Message-ID: <20210427141103.1c4d2e4d81e04ff7417761d2@bidouilliste.com> In-Reply-To: <CF4C4332-BB2F-47E9-B879-8EEA0E53E848@FreeBSD.org> References: <1C2DD11C-B1F6-4C2A-9AB0-5F1553520FF5@FreeBSD.org> <20210426161138.a8f44b6e1134f73a411be57d@bidouilliste.com> <CF4C4332-BB2F-47E9-B879-8EEA0E53E848@FreeBSD.org>
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On Tue, 27 Apr 2021 08:52:39 +0100 Mark Murray <markm@FreeBSD.org> wrote: > On 26 Apr 2021, at 15:11, Emmanuel Vadot <manu@bidouilliste.com> wrote: > > > > On Sun, 25 Apr 2021 13:32:00 +0100 > > Mark Murray <markm@FreeBSD.org> wrote: > > > >> Hi All, > >> > >> Does anyone here have IIC/I2C working on a CURRENT (I'm running latest) FreeBSD? > >> > >> I've never seen it work; Last time I had working IIC was on an RPI3. > >> > >> There is a /dev/iic0, and I have a known working RTC on it, but the scan just times out: > >> > >> [root@grasshopper ~]# i2c -s > >> Hardware may not support START/STOP scanning; trying less-reliable read method. > >> <TIMEOUT> > >> Scanning I2C devices on /dev/iic0: <none found> > >> > >> > >> I suspect something not-quite-right in DTS land, but I lack the knowledge to investigate. I've done some random stumbling around in the dark with overlays and the like, but I've either seen the above error, or a total lack of /dev/iic0. > >> > >> Thanks! > >> > >> M > >> -- > >> Mark R V Murray > >> > > > > I2C is disabled by default. > > You need to copy i2c0.dtbo (or i2c1<X> I don't know which one maps to > > the pins you want to use) in the ESP partition and add "i2c<X>" to the > > dtoverlay line in config.txt > > I want to use the i2c on the "regular" pins, GPIO2 and GPIO3, AKA physical pins 3 and 5. > > I looked at all the i2c[0-6].dtbo overlays in /usr/ports/sysutils/rpi-firmware. Only 1 had "pins = <2, 3>", so I used that one. I presume the 2,3 refers to GPIO pin numbers, not physical pin numbers? > > Same result as before - long timeout, no I2C. > > M > -- > Mark R V Murray > No they probably refer to the pin number of the SoC (but that might be the same as the "gpio number" in the pinouts naming of the hat connector. I don't have any rpi* here to help you more so hopefully someone else can/will. -- Emmanuel Vadot <manu@bidouilliste.com> <manu@FreeBSD.org>
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