Merge branch 'kvm-ppc-fix' into HEAD
[firefly-linux-kernel-4.4.55.git] / Documentation / hwmon / ltc2978
1 Kernel driver ltc2978
2 =====================
3
4 Supported chips:
5   * Linear Technology LTC2974
6     Prefix: 'ltc2974'
7     Addresses scanned: -
8     Datasheet: http://www.linear.com/product/ltc2974
9   * Linear Technology LTC2977
10     Prefix: 'ltc2977'
11     Addresses scanned: -
12     Datasheet: http://www.linear.com/product/ltc2977
13   * Linear Technology LTC2978, LTC2978A
14     Prefix: 'ltc2978'
15     Addresses scanned: -
16     Datasheet: http://www.linear.com/product/ltc2978
17                http://www.linear.com/product/ltc2978a
18   * Linear Technology LTC3880
19     Prefix: 'ltc3880'
20     Addresses scanned: -
21     Datasheet: http://www.linear.com/product/ltc3880
22   * Linear Technology LTC3883
23     Prefix: 'ltc3883'
24     Addresses scanned: -
25     Datasheet: http://www.linear.com/product/ltc3883
26
27 Author: Guenter Roeck <linux@roeck-us.net>
28
29
30 Description
31 -----------
32
33 LTC2974 is a quad digital power supply manager. LTC2978 is an octal power supply
34 monitor. LTC2977 is a pin compatible replacement for LTC2978. LTC3880 is a dual
35 output poly-phase step-down DC/DC controller. LTC3883 is a single phase
36 step-down DC/DC controller.
37
38
39 Usage Notes
40 -----------
41
42 This driver does not probe for PMBus devices. You will have to instantiate
43 devices explicitly.
44
45 Example: the following commands will load the driver for an LTC2978 at address
46 0x60 on I2C bus #1:
47
48 # modprobe ltc2978
49 # echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
50
51
52 Sysfs attributes
53 ----------------
54
55 in1_label               "vin"
56 in1_input               Measured input voltage.
57 in1_min                 Minimum input voltage.
58 in1_max                 Maximum input voltage.
59                         LTC2974, LTC2977, and LTC2978 only.
60 in1_lcrit               Critical minimum input voltage.
61                         LTC2974, LTC2977, and LTC2978 only.
62 in1_crit                Critical maximum input voltage.
63 in1_min_alarm           Input voltage low alarm.
64 in1_max_alarm           Input voltage high alarm.
65                         LTC2974, LTC2977, and LTC2978 only.
66 in1_lcrit_alarm         Input voltage critical low alarm.
67                         LTC2974, LTC2977, and LTC2978 only.
68 in1_crit_alarm          Input voltage critical high alarm.
69 in1_lowest              Lowest input voltage.
70                         LTC2974, LTC2977, and LTC2978 only.
71 in1_highest             Highest input voltage.
72 in1_reset_history       Reset input voltage history.
73
74 in[N]_label             "vout[1-8]".
75                         LTC2974: N=2-5
76                         LTC2977: N=2-9
77                         LTC2978: N=2-9
78                         LTC3880: N=2-3
79                         LTC3883: N=2
80 in[N]_input             Measured output voltage.
81 in[N]_min               Minimum output voltage.
82 in[N]_max               Maximum output voltage.
83 in[N]_lcrit             Critical minimum output voltage.
84 in[N]_crit              Critical maximum output voltage.
85 in[N]_min_alarm         Output voltage low alarm.
86 in[N]_max_alarm         Output voltage high alarm.
87 in[N]_lcrit_alarm       Output voltage critical low alarm.
88 in[N]_crit_alarm        Output voltage critical high alarm.
89 in[N]_lowest            Lowest output voltage. LTC2974 and LTC2978 only.
90 in[N]_highest           Highest output voltage.
91 in[N]_reset_history     Reset output voltage history.
92
93 temp[N]_input           Measured temperature.
94                         On LTC2974, temp[1-4] report external temperatures,
95                         and temp5 reports the chip temperature.
96                         On LTC2977 and LTC2978, only one temperature measurement
97                         is supported and reports the chip temperature.
98                         On LTC3880, temp1 and temp2 report external
99                         temperatures, and temp3 reports the chip temperature.
100                         On LTC3883, temp1 reports an external temperature,
101                         and temp2 reports the chip temperature.
102 temp[N]_min             Mimimum temperature. LTC2974, LCT2977, and LTC2978 only.
103 temp[N]_max             Maximum temperature.
104 temp[N]_lcrit           Critical low temperature.
105 temp[N]_crit            Critical high temperature.
106 temp[N]_min_alarm       Temperature low alarm.
107                         LTC2974, LTC2977, and LTC2978 only.
108 temp[N]_max_alarm       Temperature high alarm.
109 temp[N]_lcrit_alarm     Temperature critical low alarm.
110 temp[N]_crit_alarm      Temperature critical high alarm.
111 temp[N]_lowest          Lowest measured temperature.
112                         LTC2974, LTC2977, and LTC2978 only.
113                         Not supported for chip temperature sensor on LTC2974.
114 temp[N]_highest         Highest measured temperature. Not supported for chip
115                         temperature sensor on LTC2974.
116 temp[N]_reset_history   Reset temperature history. Not supported for chip
117                         temperature sensor on LTC2974.
118
119 power1_label            "pin". LTC3883 only.
120 power1_input            Measured input power.
121
122 power[N]_label          "pout[1-4]".
123                         LTC2974: N=1-4
124                         LTC2977: Not supported
125                         LTC2978: Not supported
126                         LTC3880: N=1-2
127                         LTC3883: N=2
128 power[N]_input          Measured output power.
129
130 curr1_label             "iin". LTC3880 and LTC3883 only.
131 curr1_input             Measured input current.
132 curr1_max               Maximum input current.
133 curr1_max_alarm         Input current high alarm.
134 curr1_highest           Highest input current. LTC3883 only.
135 curr1_reset_history     Reset input current history. LTC3883 only.
136
137 curr[N]_label           "iout[1-4]".
138                         LTC2974: N=1-4
139                         LTC2977: not supported
140                         LTC2978: not supported
141                         LTC3880: N=2-3
142                         LTC3883: N=2
143 curr[N]_input           Measured output current.
144 curr[N]_max             Maximum output current.
145 curr[N]_crit            Critical high output current.
146 curr[N]_lcrit           Critical low output current. LTC2974 only.
147 curr[N]_max_alarm       Output current high alarm.
148 curr[N]_crit_alarm      Output current critical high alarm.
149 curr[N]_lcrit_alarm     Output current critical low alarm. LTC2974 only.
150 curr[N]_lowest          Lowest output current. LTC2974 only.
151 curr[N]_highest         Highest output current.
152 curr[N]_reset_history   Reset output current history.