From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-serial@vger.kernel.org
Subject: Re: [PATCH] usb: cp210x: Added support for GPIO (CP2103/4/5)
Date: Sun, 29 Apr 2012 15:02:32 +0200 [thread overview]
Message-ID: <20381.15336.604590.461744@elektron.ikp.physik.tu-darmstadt.de> (raw)
In-Reply-To: <20120428203322.7680594f@pyramind.ukuu.org.uk>
>>>>> "Alan" == Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
Alan> On Sat, 28 Apr 2012 20:17:07 +0200 Uwe Bonnes
Alan> <bon@elektron.ikp.physik.tu-darmstadt.de> wrote:
>> >>>>> "Alan" == Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
>>
>> ...
Alan> The other question is whether having some custom gpio poking
Alan> interface is actually a good idea. I suspect probably not. The
Alan> kernel gpio layer can help a bit but doesn't really solve the
Alan> problem as there is no way to tie a gpio to a port. Given how many
Alan> devices seem to have gpios these days I wonder if we need a gpio
Alan> setting interface via termiox.
>> Is this really kernel stuff or better handled in libusb(x)
Alan> Tricky to do it that way when the kernel driver owns the
Alan> interface. Also it's looking increasingly like we'll need to
Alan> support a variety of "serial and a couple of extra magic lines"
Alan> type interfaces for things like SIM readers.
Well,
most RS232/USB Adapter don't supply and most applications working with these
adapters don't need hard realtime. So even writing and reading the serial
lines can be handled with libusb, like libftdi does.
But as soon as higher level protocols based on the serial line get involved,
a kernel driver is needed...
So when thinking some termiox, some thoughts for the FTDI special modes,
like MPSSE or synchronous FIFO should be spent. It would come handy if I
could open /dev/ttyUSBx, set som termiox and could use the kernel driver for
sending and receiving MPSSE commands. MPSSE is e.g. used in OpenOCD and
xc3sprog to talk e.g. JTAG to external devices.
Bye
--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de
Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 162516 -------- Fax. 06151 164321 ----------
next prev parent reply other threads:[~2012-04-29 13:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-28 16:55 [PATCH] usb: cp210x: Added support for GPIO (CP2103/4/5) Preston Fick
2012-04-28 18:05 ` Alan Cox
2012-04-28 18:17 ` Uwe Bonnes
2012-04-28 19:33 ` Alan Cox
2012-04-29 13:02 ` Uwe Bonnes [this message]
2012-04-29 14:35 ` Xiaofan Chen
2012-04-28 20:30 ` Preston Fick
2012-04-28 21:08 ` Alan Cox
2012-04-28 21:44 ` Preston Fick
2012-04-30 20:27 Preston Fick
2012-04-30 20:32 ` Greg KH
2012-05-03 20:34 ` Alan Cox
2012-05-04 15:27 ` Preston Fick
2012-05-05 0:32 ` Greg KH
2012-05-05 11:01 ` Alan Cox
2012-05-05 14:57 ` Greg KH
2012-05-16 15:33 ` Alan Cox
2012-05-16 23:41 ` Greg KH
2012-05-04 16:26 ` Alexander Stein
2012-05-04 16:33 ` Alan Cox
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