From owner-freebsd-hackers@freebsd.org Sun Nov 3 12:01:23 2019 Return-Path: Delivered-To: freebsd-hackers@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 098A81B257C for ; Sun, 3 Nov 2019 12:01:23 +0000 (UTC) (envelope-from freebsd-hackers@dino.sk) Received: from mailhost.netlabit.sk (mailhost.netlabit.sk [84.245.65.72]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 475ZJx6P8mz43gs for ; Sun, 3 Nov 2019 12:01:21 +0000 (UTC) (envelope-from freebsd-hackers@dino.sk) Received: from zeta.dino.sk (fw3.dino.sk [84.245.95.254]) (AUTH: LOGIN milan) by mailhost.netlabit.sk with ESMTPA; Sun, 03 Nov 2019 13:01:18 +0100 id 00F407DE.5DBEC18E.000122B0 Date: Sun, 3 Nov 2019 13:01:18 +0100 From: Milan Obuch To: Oleksandr Tymoshenko Cc: freebsd-hackers@freebsd.org, Oliver Pinter Subject: Re: UART driver as kld - how? Message-ID: <20191103130118.36fa6eec@zeta.dino.sk> In-Reply-To: <20191103042321.GA49790@bluezbox.com> References: <20191027214209.712d62ca@zeta.dino.sk> <20191027232956.28b11772@zeta.dino.sk> <20191028191005.GA89835@bluezbox.com> <20191028201952.20a92307@zeta.dino.sk> <20191102214100.500ba493@zeta.dino.sk> <20191103042321.GA49790@bluezbox.com> X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i386-portbld-freebsd11.3) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 475ZJx6P8mz43gs X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of freebsd-hackers@dino.sk designates 84.245.65.72 as permitted sender) smtp.mailfrom=freebsd-hackers@dino.sk X-Spamd-Result: default: False [-4.17 / 15.00]; ARC_NA(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; FROM_HAS_DN(0.00)[]; RCPT_COUNT_THREE(0.00)[3]; R_SPF_ALLOW(-0.20)[+mx]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[text/plain]; RCVD_TLS_LAST(0.00)[]; DMARC_NA(0.00)[dino.sk]; TO_DN_SOME(0.00)[]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_IN_DNSWL_NONE(0.00)[72.65.245.84.list.dnswl.org : 127.0.10.0]; IP_SCORE(-2.87)[ip: (-8.04), ipnet: 84.245.64.0/18(-4.02), asn: 16160(-2.35), country: SK(0.08)]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; SUBJECT_ENDS_QUESTION(1.00)[]; ASN(0.00)[asn:16160, ipnet:84.245.64.0/18, country:SK]; MIME_TRACE(0.00)[0:+]; RCVD_COUNT_TWO(0.00)[2] X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 03 Nov 2019 12:01:23 -0000 On Sat, 2 Nov 2019 21:23:21 -0700 Oleksandr Tymoshenko wrote: > Milan Obuch (freebsd-hackers@dino.sk) wrote: [ snip ] > > After studying other uart_dev_xxx.c files I am able to create > > working skeleton uart driver. I can compile it, kldload, and get > > some console output. Right now, I hit another problem - uart > > framework is not documented well, at least no man page is found in > > share/man directory. > > > > My probe function is similar to that in uart_dev_snps.c file, > > simplified, and I need to know what arguments should uart_bus_probe > > function be invoked with. In many device drivers there are mostly > > zeros, but this does not work for me. > > > > Currently I am getting error 6, ENXIO, so I am not correctly > > attaching my driver to device. Putting some printf here and there, > > I found test at line 508, file uart_core.c, fails - sc->sc_class is > > null. Question is, now, where and how should this field in this > > structure be initialized... > > > > I am sure I need docs/description for other functions as well, so if > > anybody knows where good uart framework description could be found, > > please advice. Or if somebody already has good understanding of it > > and could help me with my issues, it wil be greatly appreciated. > > if you follow uart_dev_snsps.c template, the sc_class is set in > probe function: > > uart_class = (struct uart_class > *)ofw_bus_search_compatible(dev, compat_data)->ocd_data; > if (uart_class == NULL) > return (ENXIO); > > freq = 0; > sc = device_get_softc(dev); > sc->ns8250.base.sc_class = uart_class; > *facepalm* I totally overlooked the obvious... yes, you are right. [ snip ] > In your case, my guess would be: you either do not set the sc_class > member var in probe function or your base var is not the first in the > struct. > Back to testing... probe function now does work, so I am going to analyze what should be done in attach... and why I am getting now panic... I'll write again when I find another obstacle I do not understand or I have working driver, whatever comes first :) Regards, Milan