Re: i2c Device Detection

[Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>]

Bonjour Gerard,

On Thu, 16 Dec 2010 09:20:00 -0500, Gerard Pierre wrote:
> Being relatively new to i2c I wanted to verify that my conclusion
> reached from doing some initial reading on i2c device detection is
> accurate:
> 
> Based on the nature of an i2c bus there is no automatic detection of
> an i2c device "plugged into" a system in the kernel. For example, an
> embedded Linux system boots up and 10 minutes later someone attaches a
> smart battery to the running system (to a bus that also has a smart
> battery charger, for example) - there is no way to automatically
> detect the device and run some initialization code in a device driver
> every time the battery gets connected to the i2c bus, correct?

Correct. You'll need a side-band mechanism for the notification. For
example, inserting the battery could push on a switch, triggering an
interrupt.

An alternative would be to poll continuously for the slave I2C address
of the battery, but that would be horrible performance-wise and thus
better avoided.

-- 
Jean Delvare