Date: Fri, 6 Feb 2015 23:03:58 +1030 From: "O'Connor, Daniel" <darius@dons.net.au> To: Hans Petter Selasky <hps@selasky.org> Cc: FreeBSD Hackers <freebsd-hackers@freebsd.org> Subject: Re: Two drivers sharing a single PCI device Message-ID: <F6DF0E64-EFFC-4CC9-8375-85F88AE0941F@dons.net.au> In-Reply-To: <54D4ABA6.805@selasky.org> References: <643918BB-810C-4FB2-AE1A-C4CDA6C8A661@dons.net.au> <54D4ABA6.805@selasky.org>
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> On 6 Feb 2015, at 22:25, Hans Petter Selasky <hps@selasky.org> wrote: > On 02/06/15 04:50, O'Connor, Daniel wrote: >> Hi, >> I am working on an EHCI debug driver and I have the basics working = (attach, probe for a debug dongle and send data back and forth) - = https://bitbucket.org/DJOConnor/dbgp >>=20 >> However one problem remaining is that for it to work you have to = detach the EHCI driver (obviously rather suboptimal :) so I am wondering = what the best way would be to allow both ehci and dbgp to attach to the = same PCI device. >>=20 >> The dbgp driver doesn't touch the EHCI registers once it's running = but it does have some code to start the EHCI controller and reset the = port during attach. >>=20 >> I can modify echi so it uses RF_SHAREABLE which should allow them to = get newbus handles to the same area but the problem is that only one = probe routine gets called. >=20 > You possibly want "D_TRACKCLOSE" in d_flags in your cdevsw. > What's the advantage of using the debug port over the regular EHCI USB = interface? I don't think that would help. It is supposed to be (largely) separate = from the regular EHCI controller - it has it's own register set and it = can steal the debug port from the regular controller so it doesn't = appear occupied (although there is a bit of messing around on port = reset). The advantage is that it runs separately to the EHCI interface and it is = quite simple to talk to, there is more information in appendix C of the = USB 2 spec (usb_20.pdf). -- Daniel O'Connor "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C
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