drivers/ina2xx: Fixed missing i2c_acquire/release

[maribu]

Contribution description

• Adding missing calls to i2c_acquire() and i2c_release()
• Added some debug output

Testing procedure

• tests/driver_ina2xx should now work on all boards

Issues/PRs references

Found while testing #13037

[maribu]

Output of the test on the MSB-A2 now is:

2020-02-10 10:34:10,324 # main(): This is RIOT! (Version: 2020.04-devel-309-g7975d-ben)
2020-02-10 10:34:10,326 # INA2XX sensor driver test application
2020-02-10 10:34:10,326 # 
2020-02-10 10:34:10,328 # Initializing INA2XX sensor at I2C_0, address 0x00000040
2020-02-10 10:34:10,329 # [OK]
2020-02-10 10:34:10,331 # +------------+--------------+----------+--------+
2020-02-10 10:34:10,333 # | U_Bus [mV] | U_Shunt [µV] |  I [µA]  | P [µW] |
2020-02-10 10:34:10,336 # +------------+--------------+----------+--------+
2020-02-10 10:34:10,338 # |        860 |           50 |        0 |      0 |
2020-02-10 10:34:10,435 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:10,563 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:10,691 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:10,819 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:10,947 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,074 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,201 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,330 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,458 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,586 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,713 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,841 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:11,969 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,097 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,225 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,366 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,494 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,622 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,750 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:12,878 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,007 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,135 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,262 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,391 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,519 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,646 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,774 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:13,902 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,030 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,158 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,285 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,413 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,541 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,669 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,796 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:14,924 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,052 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,180 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,308 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,435 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,563 # |        852 |           10 |       20 |      0 |
2020-02-10 10:34:15,691 # |        852 |           10 |       20 |      0 |

(No load connected, the ADC pins are floating; so the measurements are garbage.)

[maribu]

@fjmolinas: This should be backported to the release, right?

[benpicco]

Code looks good and except for the init function, this does not generate multiple acquire()/release() pairs in a single function.

The added error handling is a nice touch too :)