Hi John! Thanks for the dts examples.
Lets say I want to develop a simple osziloscop application and the user should be able to choose the sampling rate or the number of channels. Therefor changing the device tree overlay is necessary, right? And since unloading an overlay is unsave in some kernel versions, the application has to reboot? That's anoying. One spends a lot of time to find and test a kernel feature, just to find out that it's unuseable for most practical purposes. BR Am Donnerstag, 3. März 2016 07:56:21 UTC+1 schrieb john3909: > > /* > * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ > * > * This program is free software; you can redistribute it and/or modify > * it under the terms of the GNU General Public License version 2 as > * published by the Free Software Foundation. > */ > /dts-v1/; > /plugin/; > > / { > compatible = "ti,beaglebone", "ti,beaglebone-black", "ti,beaglebone-green"; > > /* identification */ > part-number = "BB-ADC"; > version = "00A0"; > > /* state the resources this cape uses */ > exclusive-use = > /* the pin header uses */ > "P9.31", /* AIN0 */ > "P9.40", /* AIN1 */ > "P9.37", /* AIN2 */ > "P9.38", /* AIN3 */ > "P9.33", /* AIN4 */ > "P9.36", /* AIN5 */ > "P9.35", /* AIN6 */ > /* the hardware ip uses */ > "tscadc"; > > fragment@0 { > target = <&tscadc>; > __overlay__ { > > status = "okay"; > adc { > ti,adc-channels = <0 1 2 3 4 5 6>; > ti,chan-step-avg = <0x1 0x1 0x1 0x1 0x1 0x1 0x1>; > ti,chan-step-opendelay = <0x98 0x98 0x98 0x98 0x98 0x98 0x98>; > ti,chan-step-sampledelay = <0x0 0x0 0x0 0x0 0x0 0x0 0x0>; > }; > }; > }; > }; > > So the speed is selected by changing the number of samples in averaging > and the open delay and sample delay. > > Regards, > John > > > > > On Mar 2, 2016, at 10:52 PM, TJF <jeli.f...@gmail.com <javascript:>> > wrote: > > Hi John! > > Am Donnerstag, 3. März 2016 00:07:02 UTC+1 schrieb john3909: >> >> For example, do: >> >> dd if=/dev/iio:device0 of=~/test >> >> Enable the iio buffer and your file will receive samples at the >> configured speed. >> > > Thanks for your statement. An interesting solution, I didn't find that yet. > > From my point of view this is a big issue for BB[WBG?]. Most of the IO > kernel features are badly documented. For a kernel novice, features are > > 1. hard to find and > 2. hard to understand. (Especially for non-native speakers.) > > One or more examples in each documentation would help a lot, like the one > you posted here (How to configure speed? How to set up step configurations? > Does it solve the iio miss-sampling issue, appearing at multi channel > sampling in single mode?). > > Anyway, my prefered solution is still libpruio since it > > - doesn't load the ARM CPU > - offers a lot of further features (ie. scaling for 13 to 16 bit or > triggering the measurement start by up to four events) > - can act in concert with the other PRU (important for hard real-time > requirements > 10 kHz). > > BR > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard...@googlegroups.com <javascript:>. > For more options, visit https://groups.google.com/d/optout. > > > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
