I2c driver notes

2022-01-20 THU

Want to see whether there is a means in Zephyr RTOS 2.6.0, to re-attempt I2C peripheral initialization after a failed attempt. Looking first at some source files in `[west_workspace]/zephyr/drivers/i2c`. File `i2c_gpio.c` has some interesting routines, but first worth noting is that in includes "zephyr/include/drivers/i2c.h". This header file gives the prototypes for the core I2C peripheral API. It's agnostic about a particular peripheral, hardware or software implemented. Sign of this is in the parameter lists of API routines here which accept a Zephyr device pointer. We can reasonably surmise that this pointer will already by initialized by the time these API routines such as `i2c_reg_read_byte(const struct device *dev, . . .)` are called.

A second place we search for Zephyr peripheral initializing code is in our Zephyr app's build directory . . .

NOTE: `[app...build/zephyr/include/generated