1 Kernel driver ltc4245
2 =====================
3
4 Supported chips:
5
6 * Linear Technology LTC4245
7
8 Prefix: 'ltc4245'
9
10 Addresses scanned: 0x20-0x3f
11
12 Datasheet:
13
14 http://www.linear.com/pc/downloadDocum
15
16 Author: Ira W. Snyder <iws@ovro.caltech.edu>
17
18
19 Description
20 -----------
21
22 The LTC4245 controller allows a board to be sa
23 from a live backplane in multiple supply syste
24 PCI Express.
25
26
27 Usage Notes
28 -----------
29
30 This driver does not probe for LTC4245 devices
31 of the possible addresses are unfriendly to pr
32 instantiate the devices explicitly.
33
34 Example: the following will load the driver fo
35 on I2C bus #1::
36
37 $ modprobe ltc4245
38 $ echo ltc4245 0x23 > /sys/bus/i2c/dev
39
40
41 Sysfs entries
42 -------------
43
44 The LTC4245 has built-in limits for over and u
45 makes it very likely that the reference circui
46
47 This driver uses the values in the datasheet t
48 into the values specified in the sysfs-interfa
49 rely on the sense resistors listed in Table 2:
50
51 ======================= ======================
52 in1_input 12v input voltage (mV)
53 in2_input 5v input voltage (mV)
54 in3_input 3v input voltage (mV)
55 in4_input Vee (-12v) input volta
56
57 in1_min_alarm 12v input undervoltage
58 in2_min_alarm 5v input undervoltage
59 in3_min_alarm 3v input undervoltage
60 in4_min_alarm Vee (-12v) input under
61
62 curr1_input 12v current (mA)
63 curr2_input 5v current (mA)
64 curr3_input 3v current (mA)
65 curr4_input Vee (-12v) current (mA
66
67 curr1_max_alarm 12v overcurrent alarm
68 curr2_max_alarm 5v overcurrent alarm
69 curr3_max_alarm 3v overcurrent alarm
70 curr4_max_alarm Vee (-12v) overcurrent
71
72 in5_input 12v output voltage (mV
73 in6_input 5v output voltage (mV
74 in7_input 3v output voltage (mV
75 in8_input Vee (-12v) output volt
76
77 in5_min_alarm 12v output undervoltag
78 in6_min_alarm 5v output undervoltag
79 in7_min_alarm 3v output undervoltag
80 in8_min_alarm Vee (-12v) output unde
81
82 in9_input GPIO voltage data (see
83 in10_input GPIO voltage data (see
84 in11_input GPIO voltage data (see
85
86 power1_input 12v power usage (mW)
87 power2_input 5v power usage (mW)
88 power3_input 3v power usage (mW)
89 power4_input Vee (-12v) power usage
90 ======================= ======================
91
92
93 Note 1
94 ------
95
96 If you have NOT configured the driver to sampl
97 voltages, then the in10_input and in11_input s
98 created. The driver will sample the GPIO pin t
99 ADC as an analog voltage, and report the value
100
101 If you have configured the driver to sample al
102 then they will be sampled in round-robin fashi
103 slowly, -EAGAIN will be returned when you read
104 the sensor reading.
105
106 The LTC4245 chip can be configured to sample a
107
108 1) platform data -- see include/linux/platform
109 2) OF device tree -- add the "ltc4245,use-extr
110
111 The default mode of operation is to sample a s
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