Messages in this thread | | | Subject | Re: [Gta04-owner] [PATCH 0/4] UART slave device support - version 4 | From | "H. Nikolaus Schaller" <> | Date | Sat, 23 Jan 2016 23:04:09 +0100 |
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Am 23.01.2016 um 18:28 schrieb One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>:
>>> There is lots of stuff we probe and bind via user space - most things >>> these days in fact. That's much of why we have notifiers and udev. It's >>> frequently a win in flexibility, security and configurability to do stuff >>> via user daemons. We do it for example with all the volume management, >>> raid and disk encryption. >> >> Because volumes are something users really want to configure. They >> can change their hardware configuration every now and then. And >> there are removable media to be considered. > > Like USB bluetooth dongles, like systems with external SPI ports, or plug > in SPI devices, or plug in gps devices on other interfaces ? > >> In our UART cases the underlaying hardware can't be reconfigured. So >> there is no need to load this burden of config to the user. > > Plenty of uarts it can be or the BT can be muxed with other device > endpoints.
Please give examples where the user can configure such a chip that is soldered on the same PCB as the SoC.
> >> For BT or GPS I just want it to work the same on all devices (independently >> on how the specific chip is connected). Kernel should unify such things. >> Or it would not be a Un(iplexed)ix. > > I think you are confusing Unix and Multics.
No, If I write Unix I mean Unix. The "Un" stands for "Uniplexed" which is a pun of course. But it alludes to "Unification" giving the impression of "Simplification".
> > Unix is nothing to do with Linux and Unix was about creating a beautiful > system not by having a huge crap filled kernel,
and no crap filled user space.
> but by having only the > minimum necessary in the kernel. Unix
I think you are confusing it with the goals of microkernels (e.g. Mach or Hurd).
> was not about what was put in but > what was left out.
Exactly. It left out complexity. E.g. everything is a file. You can use devices like files. Just open some /dev/tty and get GPS NMEA records...
> > "We used to sit around in the Unix Room saying, 'What can we throw out? > Why is there this option?" - Doug McIlroy
Fine. Let's throw out the idea to configure power on/off a GPS or BT device by user space daemons for hard wired chips.
> > GPS is a train wreck for commonality. Most GPS requires custom binary > only user space code often obfuscated in order to meet the regulations > governing GPS technology to stop third parties using it for missile > guidance.
Most GPS receivers I came across are modules which spit out NMEA records with serial 9600 bit/s. Either through RS232 or Bluetooth SPP. There may be others, but I don't want to have all problems of the world solved at once.
-- hns
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