On Wed, 27 May 2009 13:08:19 +0200, Hans de Goede wrote: > > > On 05/27/2009 11:15 AM, Andre Prendel wrote: > > Hi Hans, > > > > looking in the datasheet of the TMP421 sensor chip > > > > http://focus.ti.com/docs/prod/folders/print/tmp421.html, > > > > I saw the following addresses. > > > > TMP421 100 11xx > > TMP422 100 11xx > > TMP423A 100 1100 > > TMP423B 100 1101 > > > > But the preliminary driver of your students uses 0x2a. > > > > /* Addresses to scan */ > > static unsigned short normal_i2c[] = { 0x2a, I2C_CLIENT_END }; > > > > 0x2a == 010 1010b, right? > > > > Right. > > > Do I misunderstand something? > > No, what my students did in there was wrong, they only put the > address in there to which the sample I gave them is wired > > The addresses to scan should be: > static unsigned short normal_i2c[] = { 0x1c, 0x1d, 0x1e, 0x1f, > 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; > > But we better run those past Jean, to see if any of > those are dangerous to scan by default, Jean ? 0x2a and 0x4c-0x4f are very popular addresses for hardware monitoring chips and can be scanned. 0x1c-0x1f is something new, sensors-detect doesn't even scan 0x1c-0x1e at the moment, only 0x1f is scanned (for the Maxim MAX6650/MAX6651.) Where do the 0x1c-0x1f and 0x2a addresses come from? The possible addresses listed above by Andre were only 0x4c-0x4f. On which systems are these chips found? If only on embedded systems and not on PC, the safe option would be to only scan 0x2a and 0x4c-0x4f. On embedded systems, probing won't be used anyway, so devices can be instantiated at any address, regardless of what the driver lists. Please add detection of these chips to sensors-detect, for addresses 0x2a and 0x4c-0x4f, and add them to the wiki. -- Jean Delvare
