Jean Delvare wrote: > On Mon, 12 Jan 2009 19:49:04 +0100, Hans de Goede wrote: >> Crossley, Malcolm (GE EntSol, Intelligent Platforms) wrote: >>> Hello, >>> >>> I am tasked with writing linux kernel support for the ADT7481 >>> sensor. This sensor is a dual remote, single local, sensor with an >>> extended temperature range capability on the remote sensors. >>> >>> Most of the register layout of the device is compliant with the LM90 >>> driver but unfortunately the official manufacturer ID and device ID >>> registers are not in a LM90 compliant location. >>> >>> The LM90 driver supports the ADT7481 extended temperature range >>> registers through it's ADT7461 support. >>> >>> The ADT7481 does have register values at 0xfe and 0xff but they are >>> not documented in the datasheet. >>> >>> Here is an i2cdump output: >>> 0 1 2 3 4 5 6 7 8 9 a b c d e f >>> 0123456789abcdef 00: 67 6b 00 24 08 9a 13 a9 13 24 08 9a 13 a9 13 >>> 00 gk.$?????$?????. 10: 40 00 00 00 00 00 00 00 00 a4 00 00 00 >>> 00 00 00 @........?...... 20: 98 05 07 00 00 00 00 00 00 00 00 >>> 00 00 00 00 00 ???............. 30: 6d ae 13 c0 00 00 00 00 00 >>> a9 00 00 00 81 41 02 m???.....?...?A? 40: 00 00 00 00 00 00 00 >>> 00 00 00 00 00 00 00 00 00 ................ 50: 00 00 00 00 00 >>> 00 00 00 00 00 00 00 00 00 00 00 ................ 60: 00 00 00 >>> 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 70: 08 >>> 00 00 c0 00 00 00 00 00 00 00 00 00 00 00 00 ?..?............ >>> 80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>> ................ 90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >>> 00 ................ a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 >>> 00 00 00 ................ b0: 00 00 00 00 00 00 00 00 00 00 00 >>> 00 00 00 00 00 ................ c0: 00 00 00 00 00 00 00 00 00 >>> 00 00 00 00 00 00 00 ................ d0: 00 00 00 00 00 00 00 >>> 00 00 00 00 00 00 00 00 00 ................ e0: 00 00 00 00 00 >>> 00 00 00 00 00 00 00 00 00 00 00 ................ f0: 00 00 00 >>> 00 00 00 00 00 00 00 00 00 00 00 41 62 ..............Ab >>> >>> The official manufacturer ID register is at 0x3e and the official >>> device ID register is at 0x3d. >>> >>> My question is whether it would be better to? >>> 1. Modify the lm90 driver, using undocumented registers for >>> detection and adding second >>> remote channel support >>> Or >>> 2. Write a new driver from scratch but borrow code from the >>> existing LM90 driver >>> >>> I would like to get this driver included into the kernel. >>> >> >> I think one would be the best, if the changes are not to invasive >> (which they probably are not). > > I beg to disagree. The lm90 driver already supports a lot of > different devices. The ADT7481 differs in a significant way in that > it supports an additional external sensor. This is probably the right > time to start a new driver. Then maybe the support for the ADT7461 > can be moved to this new driver so that the lm90 driver can be > simplified a bit. I attempted to modify the lm90 driver and discovered that fairly invasive changes were required to support a larger driver structure for storing the sensors values. I would not move the ADT7461 into a driver for the ADT7481 because the structure would differ as above ( structure for 2 channel device vs 3 channel device) and the registers for device detection are in different locations. I have created a separate ADT7481 driver based upon the LM90 structure. It's still needs a clean up but it's been tested and it has PEC support included (full PEC support not the half adm1032 support). > > For now it would be good to add the ADT7481 to wiki/Devices and > detection to sensors-detect. > Will do the wiki entry, see below for sensors-detect. > Malcolm, if you want an account on lm-sensors' wiki, please send _me_ > the output of the following command: htdigest -c $user-passwd > lm-sensors/i2c $user where $user is your desired login. > Sent in another email. > Can you please also send us a patch against the latest version of > sensors-detect: > http://www.lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0/prog/ detect/sensors-detect > adding detection of the ADT7481? > > Thanks, Unfortunately I can only use Outlook at work currently and so it will be difficult to send patches to mailing lists without breaking them. I have a colleague(Martyn Welch) with a better email setup who can send patches on my behalf. I am working towards a better email setup but it will take some weeks (IT issues). -- Malcolm Crossley, Software Engineer, Embedded Systems, GE Fanuc Intelligent Platforms GE Fanuc Intelligent Platforms Ltd, registered in England and Wales (3828642) at 100 Barbirolli Square, Manchester, M2 3AB, VAT GB 729 849 476
