Date: Tue, 14 Jul 2009 07:08:40 +0000 From: Norbert Koch <nkoch@demig.de> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: bus device driver Message-ID: <4A5C2EF8.3080208@demig.de> In-Reply-To: <200907131435.30452.jhb@freebsd.org> References: <4A5B3F1B.3040207@demig.de> <200907131435.30452.jhb@freebsd.org>
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John Baldwin schrieb: > On Monday 13 July 2009 10:05:15 am Norbert Koch wrote: > >> Hello. >> >> I just started to write a device >> driver for a multi-function pci card. >> This card replaces a number of >> independant isa hardware devices. >> This pci card contains memory, i/o >> and interrupt sources. >> I want my device driver to >> serve as a bus driver between >> the pci driver and the specific >> device drivers. >> >> Do I need more than the following (see below)? >> Do I have to do any bookkeeping for allocated resources? >> > > How do the child devices receive resources? Do they suballocate regions from > BARs in the PCI device or is your device a subtractive bridge that will > forward requests for ISA ranges and your devices all use ISA ranges? > > I am not quite sure that I understand what you mean. What is the difference? My old device drivers were isa based. We had all our resources in the 15-16M isa hole. So I want to change them to just allocate resources from the pci bus through the bus device driver. I thought it would be sufficient to just forward *_alloc_resource calls directly to the pci driver. Clearly, my drivers will have to know that they are just forwarded through to pci and have to know what sub-resources to allocate. -- Dipl.-Ing. Norbert Koch Entwicklung Prozessregler ***************************************** * demig Prozessautomatisierung GmbH * * * * Anschrift: Haardtstrasse 40 * * D-57076 Siegen * * Registergericht: Siegen HRB 2819 * * Geschaeftsfuehrer: Joachim Herbst, * * Winfried Held * * Telefon: +49 271 772020 * * Telefax: +49 271 74704 * * E-Mail: info@demig.de * * http://www.demig.de * *****************************************
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