On Tue, 16 Feb 2010 14:23:49 -0700 Grant Likely <[email protected]> wrote:
> On Tue, Feb 16, 2010 at 11:59 AM, Ernst Schwab <[email protected]> wrote: > > Grant Likely <[email protected]> wrote: > > > >> Add a property to the /chosen node to assign short labels to devices. > > > > I'm not familiar with this and will check - does anyone know of an > > existing example for this? > > Oops, sorry. I meant the 'aliases' node. 'chosen' is for something else. > > Properties in the aliases node are simply name = "/path/to/node"; > pairs. Do "grep -A 6 arch/powerpc/boot/dts/" to see lots of examples. > dtc expands the <name> = &label; construct into the full path to the > node. Ok, as I did the grep with "chosen" there wasn't anything, "aliases" looks much better. I was aware of this node, but had no idea how to use it. Actually, I still do not exactly know how to use it ;-). > Use the alias to find the spi bus you care about in /sys/devices/. > Then whichever eeprom has that bus as its parent is the device you > want. You can read the expanded device tree in /proc/device-tree. > Unfortunately I don't have sample code that shows how to do this; I > haven't had to do so personally yet. I created aliases { ... spi0 = &spi; eepmain = &eepmain; }; spi:s...@7000 { ... eepmain:eep...@8 { ... }; }; The aliases are visible at /proc/device-tree/aliases/: eepmain : contains /i...@e0000000/s...@7000/eep...@8 spi0 : contains /i...@e0000000/s...@7000 The EEPROM can be accessed under /sys/bus/spi/devices/spi32766.8/eeprom The alias names do not appear in /sys as far as I can see. The paths (e.g. /i...@e0000000/s...@7000) seems not to be useable to address something in the /sys directory directly. Does this mean that software which wants to access 'eepmain' has to reformat the alias value to construct a path in the sysfs to access the EEPROM contents? Regards Ernst ------------------------------------------------------------------------------ SOLARIS 10 is the OS for Data Centers - provides features such as DTrace, Predictive Self Healing and Award Winning ZFS. Get Solaris 10 NOW http://p.sf.net/sfu/solaris-dev2dev _______________________________________________ spi-devel-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/spi-devel-general
