GNU Linux-libre 4.14.266-gnu1
[releases.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 LTC2975
10     Prefix: 'ltc2975'
11     Addresses scanned: -
12     Datasheet: http://www.linear.com/product/ltc2975
13   * Linear Technology LTC2977
14     Prefix: 'ltc2977'
15     Addresses scanned: -
16     Datasheet: http://www.linear.com/product/ltc2977
17   * Linear Technology LTC2978, LTC2978A
18     Prefix: 'ltc2978'
19     Addresses scanned: -
20     Datasheet: http://www.linear.com/product/ltc2978
21                http://www.linear.com/product/ltc2978a
22   * Linear Technology LTC2980
23     Prefix: 'ltc2980'
24     Addresses scanned: -
25     Datasheet: http://www.linear.com/product/ltc2980
26   * Linear Technology LTC3880
27     Prefix: 'ltc3880'
28     Addresses scanned: -
29     Datasheet: http://www.linear.com/product/ltc3880
30   * Linear Technology LTC3882
31     Prefix: 'ltc3882'
32     Addresses scanned: -
33     Datasheet: http://www.linear.com/product/ltc3882
34   * Linear Technology LTC3883
35     Prefix: 'ltc3883'
36     Addresses scanned: -
37     Datasheet: http://www.linear.com/product/ltc3883
38   * Linear Technology LTC3886
39     Prefix: 'ltc3886'
40     Addresses scanned: -
41     Datasheet: http://www.linear.com/product/ltc3886
42   * Linear Technology LTC3887
43     Prefix: 'ltc3887'
44     Addresses scanned: -
45     Datasheet: http://www.linear.com/product/ltc3887
46   * Linear Technology LTM2987
47     Prefix: 'ltm2987'
48     Addresses scanned: -
49     Datasheet: http://www.linear.com/product/ltm2987
50   * Linear Technology LTM4675
51     Prefix: 'ltm4675'
52     Addresses scanned: -
53     Datasheet: http://www.linear.com/product/ltm4675
54   * Linear Technology LTM4676
55     Prefix: 'ltm4676'
56     Addresses scanned: -
57     Datasheet: http://www.linear.com/product/ltm4676
58
59 Author: Guenter Roeck <linux@roeck-us.net>
60
61
62 Description
63 -----------
64
65 LTC2974 and LTC2975 are quad digital power supply managers.
66 LTC2978 is an octal power supply monitor.
67 LTC2977 is a pin compatible replacement for LTC2978.
68 LTC2980 is a 16-channel Power System Manager, consisting of two LTC2977
69 in a single die. The chip is instantiated and reported as two separate chips
70 on two different I2C bus addresses.
71 LTC3880, LTC3882, LTC3886, and LTC3887 are dual output poly-phase step-down
72 DC/DC controllers.
73 LTC3883 is a single phase step-down DC/DC controller.
74 LTM2987 is a 16-channel Power System Manager with two LTC2977 plus
75 additional components on a single die. The chip is instantiated and reported
76 as two separate chips on two different I2C bus addresses.
77 LTM4675 is a dual 9A or single 18A μModule regulator
78 LTM4676 is a dual 13A or single 26A uModule regulator.
79
80
81 Usage Notes
82 -----------
83
84 This driver does not probe for PMBus devices. You will have to instantiate
85 devices explicitly.
86
87 Example: the following commands will load the driver for an LTC2978 at address
88 0x60 on I2C bus #1:
89
90 # modprobe ltc2978
91 # echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
92
93
94 Sysfs attributes
95 ----------------
96
97 in1_label               "vin"
98 in1_input               Measured input voltage.
99 in1_min                 Minimum input voltage.
100 in1_max                 Maximum input voltage.
101                         LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
102                         LTM2987 only.
103 in1_lcrit               Critical minimum input voltage.
104                         LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
105                         LTM2987 only.
106 in1_crit                Critical maximum input voltage.
107 in1_min_alarm           Input voltage low alarm.
108 in1_max_alarm           Input voltage high alarm.
109                         LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
110                         LTM2987 only.
111 in1_lcrit_alarm         Input voltage critical low alarm.
112                         LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
113                         LTM2987 only.
114 in1_crit_alarm          Input voltage critical high alarm.
115 in1_lowest              Lowest input voltage.
116                         LTC2974, LTC2975, LTC2977, LTC2980, LTC2978, and
117                         LTM2987 only.
118 in1_highest             Highest input voltage.
119 in1_reset_history       Reset input voltage history.
120
121 in[N]_label             "vout[1-8]".
122                         LTC2974, LTC2975: N=2-5
123                         LTC2977, LTC2980, LTM2987: N=2-9
124                         LTC2978: N=2-9
125                         LTC3880, LTC3882, LTC23886 LTC3887, LTM4675, LTM4676:
126                                 N=2-3
127                         LTC3883: N=2
128 in[N]_input             Measured output voltage.
129 in[N]_min               Minimum output voltage.
130 in[N]_max               Maximum output voltage.
131 in[N]_lcrit             Critical minimum output voltage.
132 in[N]_crit              Critical maximum output voltage.
133 in[N]_min_alarm         Output voltage low alarm.
134 in[N]_max_alarm         Output voltage high alarm.
135 in[N]_lcrit_alarm       Output voltage critical low alarm.
136 in[N]_crit_alarm        Output voltage critical high alarm.
137 in[N]_lowest            Lowest output voltage. LTC2974, LTC2975,
138                         and LTC2978 only.
139 in[N]_highest           Highest output voltage.
140 in[N]_reset_history     Reset output voltage history.
141
142 temp[N]_input           Measured temperature.
143                         On LTC2974 and LTC2975, temp[1-4] report external
144                         temperatures, and temp5 reports the chip temperature.
145                         On LTC2977, LTC2980, LTC2978, and LTM2987, only one
146                         temperature measurement is supported and reports
147                         the chip temperature.
148                         On LTC3880, LTC3882, LTC3887, LTM4675, and LTM4676,
149                         temp1 and temp2 report external temperatures, and temp3
150                         reports the chip temperature.
151                         On LTC3883, temp1 reports an external temperature,
152                         and temp2 reports the chip temperature.
153 temp[N]_min             Mimimum temperature. LTC2974, LCT2977, LTM2980, LTC2978,
154                         and LTM2987 only.
155 temp[N]_max             Maximum temperature.
156 temp[N]_lcrit           Critical low temperature.
157 temp[N]_crit            Critical high temperature.
158 temp[N]_min_alarm       Temperature low alarm.
159                         LTC2974, LTC2975, LTC2977, LTM2980, LTC2978, and
160                         LTM2987 only.
161 temp[N]_max_alarm       Temperature high alarm.
162 temp[N]_lcrit_alarm     Temperature critical low alarm.
163 temp[N]_crit_alarm      Temperature critical high alarm.
164 temp[N]_lowest          Lowest measured temperature.
165                         LTC2974, LTC2975, LTC2977, LTM2980, LTC2978, and
166                         LTM2987 only.
167                         Not supported for chip temperature sensor on LTC2974 and
168                         LTC2975.
169 temp[N]_highest         Highest measured temperature. Not supported for chip
170                         temperature sensor on LTC2974 and LTC2975.
171 temp[N]_reset_history   Reset temperature history. Not supported for chip
172                         temperature sensor on LTC2974 and LTC2975.
173
174 power1_label            "pin". LTC3883 and LTC3886 only.
175 power1_input            Measured input power.
176
177 power[N]_label          "pout[1-4]".
178                         LTC2974, LTC2975: N=1-4
179                         LTC2977, LTC2980, LTM2987: Not supported
180                         LTC2978: Not supported
181                         LTC3880, LTC3882, LTC3886, LTC3887, LTM4675, LTM4676:
182                                 N=1-2
183                         LTC3883: N=2
184 power[N]_input          Measured output power.
185
186 curr1_label             "iin". LTC3880, LTC3883, LTC3886, LTC3887, LTM4675,
187                         and LTM4676 only.
188 curr1_input             Measured input current.
189 curr1_max               Maximum input current.
190 curr1_max_alarm         Input current high alarm.
191 curr1_highest           Highest input current. LTC3883 and LTC3886 only.
192 curr1_reset_history     Reset input current history. LTC3883 and LTC3886 only.
193
194 curr[N]_label           "iout[1-4]".
195                         LTC2974, LTC2975: N=1-4
196                         LTC2977, LTC2980, LTM2987: not supported
197                         LTC2978: not supported
198                         LTC3880, LTC3882, LTC3886, LTC3887, LTM4675, LTM4676:
199                                 N=2-3
200                         LTC3883: N=2
201 curr[N]_input           Measured output current.
202 curr[N]_max             Maximum output current.
203 curr[N]_crit            Critical high output current.
204 curr[N]_lcrit           Critical low output current. LTC2974 and LTC2975 only.
205 curr[N]_max_alarm       Output current high alarm.
206 curr[N]_crit_alarm      Output current critical high alarm.
207 curr[N]_lcrit_alarm     Output current critical low alarm.
208                         LTC2974 and LTC2975 only.
209 curr[N]_lowest          Lowest output current. LTC2974 and LTC2975 only.
210 curr[N]_highest         Highest output current.
211 curr[N]_reset_history   Reset output current history.