Pin usage reference

Since ARM and VideoCore share the same pin space, the concurrent access on the same pins must be avoided. The Firmware DT blob already describe the pins which are used by the GPU firmware, but it's not very practical. So here is a reference table:

Pin	RPi 1 A+	RPi 1 B r1	RPi 1 B r2	RPi 1 B+	RPi CM1	RPi 0	RPi 0 W	RPi 2 B	RPi 3 B	RPi CM3
0			CAM
1			CAM
2		CAM
3		CAM
4
5		CAM	CAM
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21			CAM
22
23
24
25
26
27		CAM
28	CAM			CAM		CAM	CAM	CAM
29	CAM			CAM		CAM	CAM	CAM
30
31
32	CAM			CAM		CAM		CAM
33
34
35
36
37
38
39
40	AUD	AUD	AUD	AUD			CAM	AUD	AUD
41	CAM			CAM		CAM		CAM	AUD
42								SMPS
43								SMPS
44							CAM		CAM
45	AUD	AUD	AUD	AUD				AUD	CAM
46									SMPS	SMPS
47									SMPS	SMPS
48
49
50
51
52
53