[lm-sensors] [PATCH 0/2 v2] hwmon: (ltc4245) fix GPIO support

[Ira W. Snyder]

This patch series fixes support for using a GPIO line as an analog input to
the ADC on the LTC4245 chip. Jean suggested dropping support for multiple
GPIO lines, and then adding it back as an optional feature.

I think this is fairly unintrusive to the ltc4245 code, and the multi-GPIO
support is well encapsulated in a seperate function, hidden behind a kernel
configuration option.

I have tested the sensors utility with the -EAGAIN code for stale values.
The output looks like this:

ltc4245-i2c-1-22
12V  Input:      +11.66 V
5.0V Input:       +5.10 V
3.3V Input:       +3.19 V
VEE  Input:       +0.00 V
12V  Output:     +11.66 V
5.0V Output:      +5.08 V
3.3V Output:      +3.19 V
VEE  Output:      +0.00 V
Dig 3.30v Output: +3.26 V
ERROR: Can't get value of subfeature in10_input: Can't read
Dig 2.25v Output: +0.00 V
ERROR: Can't get value of subfeature in11_input: Can't read
Dig 1.80v Output: +0.00 V
12V  Power:      816.20 mW
5.0V Power:        4.90 W
3.3V Power:        1.44 W
VEE  Power:        0.00 nW
12V  Current:     +0.07 A
5.0V Current:     +0.96 A
3.3V Current:     +0.45 A
VEE  Current:     +0.00 A

Using cat to read the inX_input nodes, I get the expected output:

cat: in9_input: Resource temporarily unavailable

So I think that the lm-sensors software will handle this method of showing
stale values just fine.

Thanks,
Ira