| The I2C protocol knows about two kinds of device addresses: normal 7 bit | |
| addresses, and an extended set of 10 bit addresses. The sets of addresses | |
| do not intersect: the 7 bit address 0x10 is not the same as the 10 bit | |
| address 0x10 (though a single device could respond to both of them). | |
| I2C messages to and from 10-bit address devices have a different format. | |
| See the I2C specification for the details. | |
| The current 10 bit address support is minimal. It should work, however | |
| you can expect some problems along the way: | |
| * Not all bus drivers support 10-bit addresses. Some don't because the | |
| hardware doesn't support them (SMBus doesn't require 10-bit address | |
| support for example), some don't because nobody bothered adding the | |
| code (or it's there but not working properly.) Software implementation | |
| (i2c-algo-bit) is known to work. | |
| * Some optional features do not support 10-bit addresses. This is the | |
| case of automatic detection and instantiation of devices by their, | |
| drivers, for example. | |
| * Many user-space packages (for example i2c-tools) lack support for | |
| 10-bit addresses. | |
| Note that 10-bit address devices are still pretty rare, so the limitations | |
| listed above could stay for a long time, maybe even forever if nobody | |
| needs them to be fixed. |