Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / Documentation / hwmon / ltc2978
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+Kernel driver ltc2978
+=====================
+
+Supported chips:
+  * Linear Technology LTC2974
+    Prefix: 'ltc2974'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc2974
+  * Linear Technology LTC2977
+    Prefix: 'ltc2977'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc2977
+  * Linear Technology LTC2978, LTC2978A
+    Prefix: 'ltc2978'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc2978
+              http://www.linear.com/product/ltc2978a
+  * Linear Technology LTC3880
+    Prefix: 'ltc3880'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc3880
+  * Linear Technology LTC3883
+    Prefix: 'ltc3883'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltc3883
+  * Linear Technology LTM4676
+    Prefix: 'ltm4676'
+    Addresses scanned: -
+    Datasheet: http://www.linear.com/product/ltm4676
+
+Author: Guenter Roeck <linux@roeck-us.net>
+
+
+Description
+-----------
+
+LTC2974 is a quad digital power supply manager. LTC2978 is an octal power supply
+monitor. LTC2977 is a pin compatible replacement for LTC2978. LTC3880 is a dual
+output poly-phase step-down DC/DC controller. LTC3883 is a single phase
+step-down DC/DC controller. LTM4676 is a dual 13A or single 26A uModule
+regulator.
+
+
+Usage Notes
+-----------
+
+This driver does not probe for PMBus devices. You will have to instantiate
+devices explicitly.
+
+Example: the following commands will load the driver for an LTC2978 at address
+0x60 on I2C bus #1:
+
+# modprobe ltc2978
+# echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
+
+
+Sysfs attributes
+----------------
+
+in1_label              "vin"
+in1_input              Measured input voltage.
+in1_min                        Minimum input voltage.
+in1_max                        Maximum input voltage.
+                       LTC2974, LTC2977, and LTC2978 only.
+in1_lcrit              Critical minimum input voltage.
+                       LTC2974, LTC2977, and LTC2978 only.
+in1_crit               Critical maximum input voltage.
+in1_min_alarm          Input voltage low alarm.
+in1_max_alarm          Input voltage high alarm.
+                       LTC2974, LTC2977, and LTC2978 only.
+in1_lcrit_alarm                Input voltage critical low alarm.
+                       LTC2974, LTC2977, and LTC2978 only.
+in1_crit_alarm         Input voltage critical high alarm.
+in1_lowest             Lowest input voltage.
+                       LTC2974, LTC2977, and LTC2978 only.
+in1_highest            Highest input voltage.
+in1_reset_history      Reset input voltage history.
+
+in[N]_label            "vout[1-8]".
+                       LTC2974: N=2-5
+                       LTC2977: N=2-9
+                       LTC2978: N=2-9
+                       LTC3880, LTM4676: N=2-3
+                       LTC3883: N=2
+in[N]_input            Measured output voltage.
+in[N]_min              Minimum output voltage.
+in[N]_max              Maximum output voltage.
+in[N]_lcrit            Critical minimum output voltage.
+in[N]_crit             Critical maximum output voltage.
+in[N]_min_alarm                Output voltage low alarm.
+in[N]_max_alarm                Output voltage high alarm.
+in[N]_lcrit_alarm      Output voltage critical low alarm.
+in[N]_crit_alarm       Output voltage critical high alarm.
+in[N]_lowest           Lowest output voltage. LTC2974 and LTC2978 only.
+in[N]_highest          Highest output voltage.
+in[N]_reset_history    Reset output voltage history.
+
+temp[N]_input          Measured temperature.
+                       On LTC2974, temp[1-4] report external temperatures,
+                       and temp5 reports the chip temperature.
+                       On LTC2977 and LTC2978, only one temperature measurement
+                       is supported and reports the chip temperature.
+                       On LTC3880 and LTM4676, temp1 and temp2 report external
+                       temperatures, and temp3 reports the chip temperature.
+                       On LTC3883, temp1 reports an external temperature,
+                       and temp2 reports the chip temperature.
+temp[N]_min            Mimimum temperature. LTC2974, LCT2977, and LTC2978 only.
+temp[N]_max            Maximum temperature.
+temp[N]_lcrit          Critical low temperature.
+temp[N]_crit           Critical high temperature.
+temp[N]_min_alarm      Temperature low alarm.
+                       LTC2974, LTC2977, and LTC2978 only.
+temp[N]_max_alarm      Temperature high alarm.
+temp[N]_lcrit_alarm    Temperature critical low alarm.
+temp[N]_crit_alarm     Temperature critical high alarm.
+temp[N]_lowest         Lowest measured temperature.
+                       LTC2974, LTC2977, and LTC2978 only.
+                       Not supported for chip temperature sensor on LTC2974.
+temp[N]_highest                Highest measured temperature. Not supported for chip
+                       temperature sensor on LTC2974.
+temp[N]_reset_history  Reset temperature history. Not supported for chip
+                       temperature sensor on LTC2974.
+
+power1_label           "pin". LTC3883 only.
+power1_input           Measured input power.
+
+power[N]_label         "pout[1-4]".
+                       LTC2974: N=1-4
+                       LTC2977: Not supported
+                       LTC2978: Not supported
+                       LTC3880, LTM4676: N=1-2
+                       LTC3883: N=2
+power[N]_input         Measured output power.
+
+curr1_label            "iin". LTC3880, LTC3883, and LTM4676 only.
+curr1_input            Measured input current.
+curr1_max              Maximum input current.
+curr1_max_alarm                Input current high alarm.
+curr1_highest          Highest input current. LTC3883 only.
+curr1_reset_history    Reset input current history. LTC3883 only.
+
+curr[N]_label          "iout[1-4]".
+                       LTC2974: N=1-4
+                       LTC2977: not supported
+                       LTC2978: not supported
+                       LTC3880, LTM4676: N=2-3
+                       LTC3883: N=2
+curr[N]_input          Measured output current.
+curr[N]_max            Maximum output current.
+curr[N]_crit           Critical high output current.
+curr[N]_lcrit          Critical low output current. LTC2974 only.
+curr[N]_max_alarm      Output current high alarm.
+curr[N]_crit_alarm     Output current critical high alarm.
+curr[N]_lcrit_alarm    Output current critical low alarm. LTC2974 only.
+curr[N]_lowest         Lowest output current. LTC2974 only.
+curr[N]_highest                Highest output current.
+curr[N]_reset_history  Reset output current history.