There are some non-compliant devices that respond to reserved I2c
addresses. rp2040 behaves sanely for these addresses, so let's just
allow using them.
Fix race condition that appears on fast repeated transfers.
Add public reset function. Because application code can stall the bus,
we need to give application code a way to fix itself.
This commit takes the fixes and error reporting improvements from
jcdickinson's work and applies them without overlaying a software state
machine on top of the hardware state machine.
Also allows configuration of response to 'general call' writes.
The RP2040 datasheet indicates that I2C pins should have a limited
slew rate (Page 440 - 4.3.1.3.). This configures that for both
`I2c` and `I2cSlave`.
In addition, the pin configuration has been centralized to a single
fn.
