Messages in this thread | | | Date | Thu, 21 Aug 2008 14:59:39 -0400 | From | "'Aristeu Rozanski'" <> | Subject | Re: [PATCH v1] 8250: add support for DTR/DSR hardware flow control |
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> > > > About a RS485 ioctl: could you consider the attached files which are already > > > > in the Linux kernel (in include/asm-cris). > > > > They define a TIOCSERSETRS485 (ioctl.h), and the data structure (rs485.h) > > > > with allows to specify timings. Sounds just like what we want ? > > > > > > I had a deeper look at this for RS485 and the answer is "sort of". I've > > > reworked the structure to keep it the same size irrespective of 32/64bit > > > systems, and to make stuff flags that can be, plus add some extra u32 > > > words in case we need to (.. when we need to ;)) add stuff later. > > > > > > Comments, thoughts - will this do what people in the RS485 world need ? > > as for DTR/DSR patch, will be used the same approach? > > I'm still trying to get a sensible answer on how other Unixes handle it I did some research on that: Solaris and AIX: TC{G,S}ETX for extended options and only input flow control (DTRXOFF) SCO: {S,G}ETFLOW for configuring flow control, TXHARD, RXHARD for DTRDSR FreeBSD: cflags has 'dtrflow' and 'dsrflow'
Having the option to set individually which pins to use for input and output flow control and which ones should be on/off all the time seem to be a powerful way to do it, instead of having a "CDTRDSR".
-- Aristeu
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