On Thu, Mar 12, 2015 at 11:49:48AM -0700, Bob Feretich wrote: > On 3/12/2015 2:44 AM, Wolfram Sang wrote: > >On Wed, Mar 11, 2015 at 09:55:51PM -0700, Bob Feretich wrote: > > > >>I tried some random things and setting aliases in the dtsi file solved > >>the problem. > > > >Good. > > > >>The use of an alias to set the name of an i2c bus should > >>be documented somewhere! > > > >Well, send a patch adding some documentation where you would have liked > >to see it. > > > >Thanks, > > > > Wolfram > > > The first two places I looked for information were: > * > https://www.kernel.org/doc/Documentation/devicetree/bindings/i2c/i2c-mux.txt > > This is where I found the info on specifying the multiplexer without > aliases. It would seem logical to add the description of "how to > explicitly name child buses" here. Please do. You know best what kind of information you'd like to see there. > * https://www.kernel.org/doc/Documentation/i2c/muxes/i2c-mux-gpio > Even though this file is for gpio controlled multiplexers, it seemed > like a good spot to look for information on how to specify i2c > multiplexers in general. It only describes the board.c method of > registering adapters. (I don't know which gpio_i2cmux_platform_data > fields would be the equivalent of specifying the device tree aliases.) > Perhaps a cross-reference to the above documentation is appropriate, > since use of customized board.c files is being discouraged. Send a patch and we will see :) > Note that once device trees become dynamic and support hot plugging, the > alias bus naming solution becomes ineffective, unless there is a way to > specify a hierarchical alias that references the bus/adapter id of the > multiplexer. I2C was never considered hot-pluggable in the days. So, anyone wanting to use it this way needs to spend some effort adding it. Some steps have already been taken, though (e.g. dynamic of reconfig).
Attachment:
signature.asc
Description: Digital signature
