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. For now it would be good to add the ADT7481 to wiki/Devices and detection to 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. 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, -- Jean Delvare
