From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baurzhan Ismagulov Subject: Re: status of i2c-cpm and ds2482 Date: Fri, 8 Jan 2010 15:01:11 +0100 Message-ID: <20100108140111.GF4004@radix50.net> References: <20100108020253.GJ3388@radix50.net> <4B471647.8050806@scram.de> <20100108121723.GD4004@radix50.net> <20100108135222.49d7b834@hyperion.delvare> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20100108135222.49d7b834-ig7AzVSIIG7kN2dkZ6Wm7A@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: Jochen Friedrich , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org Hello Jean, On Fri, Jan 08, 2010 at 01:52:22PM +0100, Jean Delvare wrote: > You probably want to take a look at these 2 patches of mine which were > applied to the ds2482 driver: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=61c91f7ded640bb2b340cc89d9ca3a3ca0229c74 > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=0314b020c49c1d6cd182d2b89775bfa6686660db Yes, I studied them yesterday in detail :) . The docs in i2c are also useful to get the big picture, thank you. That said, I'm currently stuck how to make the infrastructure probe ds2482. > Before 2.6.27, the ds2482 driver was a so-called "legacy i2c driver" > probing buses randomly in search of supported chips. Since 2.6.27 is is > a so-called "new-style i2c driver" which only attaches to the devices > when told to. So what you observe is the expected behavior. It is much > safer that way. Yes, this is clear from your docs. > For an overview of how an I2C device can be declared, see: > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/i2c/instantiating-devices As I wrote yesterday, I did try Method 4. However, /sys/bus/i2c/devices/i2c-0 doesn't exist. There is also ds2482_detect in ds2482.c of 2.6.27.25 (Method 3); still cannot see /sys/devices/w1_bus_master1. What is the problem there? Should I update some infrastructure files from 2.6 git? For now, I can't use newer kernels since they either hang or run very slowly ("time id" taking real 32s) on my board. > One method not described in this document is listing the device in a > dts. It should probably be added, unfortunately I don't know enough > about this myself to do it. Any volunteer? I would gladly contribute that as soon as I learn how to do that :) . Thanks in advance, Baurzhan.