Date: Mon, 4 Feb 2013 21:17:49 +0100 From: Damjan Marion <damjan.marion@gmail.com> To: Ian Lepore <ian@FreeBSD.org> Cc: freebsd-arm@FreeBSD.org Subject: Re: Beaglebone Serial Ports Message-ID: <6201EAD1-31FC-49C0-A990-D32EEBE4EF6F@gmail.com> In-Reply-To: <1359818003.93359.381.camel@revolution.hippie.lan> References: <510CE8E0.9070102@g7iii.net> <1359818003.93359.381.camel@revolution.hippie.lan>
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On Feb 2, 2013, at 4:13 PM, Ian Lepore <ian@FreeBSD.org> wrote: > On Sat, 2013-02-02 at 10:22 +0000, Iain Young wrote: >> Hi Folks, >>=20 >> Just a quick question with regards to some clarification serial ports >> on the Beaglbone and FreeBSD. Am I correct in deducing that FreeBSD >> lacks support for UARTS1 thru 5 at the moment ? >>=20 >> I can see what I believe to be UART0 (which is attached to the USB) = as >> /dev/cuau0, but not the others. A few finds and greps through the >> kernel source didn't show up anything obvious either. >>=20 >> Is any one working on them ? Or is there a kernel module or option >> that I need to enable for them to build ? >>=20 >=20 > According to the datasheet all the onboard uarts should be supported = by > our standard uart driver (but only uart1 has all the modem-control = lines > wired). Two things need to be done to enable them: add entries to > the .dts file (easy), and configure the multipurpose pins for them at > runtime. I have no idea how we handle the latter in the FDT world. = In > the pre-FDT world it was pretty much ad-hoc and board-support routines > that ran at startup configured pins for that board. Actually it should be quite simple. There is pinmux section in DTS file = where you can configure each pin you need. I put into DTS file only stuff which is hardwired on board. That's the = reason why just 1st serial port is enabled. To enable other serial ports just DTS file needs to be edited: 1) into SCM configuration proper triplets <padname, muxname, padstate> = should be inserted, =20 possible values are in sys/arm/ti/am335x/am335x_scm_padconf.c 2) uart0 config can be copied with modified memory address and = interrupt (proper values can be found in TRM) Would like to hear if it works as I never tried :) Damjan=
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