[lm-sensors] i2c device w/o registers

Ben Dooks ben at trinity.fluff.org
Tue Jun 7 10:18:39 CEST 2011


On Mon, Jun 06, 2011 at 05:25:10PM -0700, Randy wrote:
> I have an ADC (MCP3424) that doesn't use registers/commands. 
> 
> To configure the device, you simply write the configuration to the appropriate 
> I2C device address.
> 
> To read the sensor data, you simply issue a read to the device, which will 
> return the ADC sample and the current control register (3 or 4 bytes total, 
> depending on mode).
> 
> All the commands in i2c-tools and the i2c drivers, except for the read/write 
> byte commands, want to take an additional register parameter.  This extra param 
> going over the wire messes up the chip.
> 
> Is there any simple way to support devices that don't support registers?  I 
> searched the archive, and found some requests for a i2c_smbus_read_word() 
> command, but that's about it.

you can send direct i2c commands to the device without any register
access by using i2c_transfer with an "struct i2c_msg" to do anything
you like.

-- 
Ben Dooks, ben at fluff.org, http://www.fluff.org/ben/

Large Hadron Colada: A large Pina Colada that makes the universe disappear.





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