1Kernel driver max197
 2====================
 3
 4Author:
 5
 6  * Vivien Didelot <vivien.didelot@savoirfairelinux.com>
 7
 8Supported chips:
 9
10  * Maxim MAX197
11
12    Prefix: 'max197'
13
14    Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX197.pdf
15
16  * Maxim MAX199
17
18    Prefix: 'max199'
19
20    Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX199.pdf
21
22Description
23-----------
24
25The A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V,
2612-Bit DAS with 8+4 Bus Interface and Fault Protection.
27
28The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V,
29while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.
30
31Platform data
32-------------
33
34The MAX197 platform data (defined in linux/platform_data/max197.h) should be
35filled with a pointer to a conversion function, defined like::
36
37    int convert(u8 ctrl);
38
39ctrl is the control byte to write to start a new conversion.
40On success, the function must return the 12-bit raw value read from the chip,
41or a negative error code otherwise.
42
43Control byte format:
44
45======= ========== ============================================
46Bit     Name       Description
477,6     PD1,PD0    Clock and Power-Down modes
485       ACQMOD     Internal or External Controlled Acquisition
494       RNG        Full-scale voltage magnitude at the input
503       BIP        Unipolar or Bipolar conversion mode
512,1,0   A2,A1,A0   Channel
52======= ========== ============================================
53
54Sysfs interface
55---------------
56
57  ============== ==============================================================
58  in[0-7]_input  The conversion value for the corresponding channel.
59		 RO
60
61  in[0-7]_min    The lower limit (in mV) for the corresponding channel.
62		 For the MAX197, it will be adjusted to -10000, -5000, or 0.
63		 For the MAX199, it will be adjusted to -4000, -2000, or 0.
64		 RW
65
66  in[0-7]_max    The higher limit (in mV) for the corresponding channel.
67		 For the MAX197, it will be adjusted to 0, 5000, or 10000.
68		 For the MAX199, it will be adjusted to 0, 2000, or 4000.
69		 RW
70  ============== ==============================================================