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authorLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 16:25:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-10-25 16:25:31 -0700
commitb20f9e5bddddb5ef0d743d6e0d409ffc8cf9fc56 (patch)
tree7654b53ebb9af77b5daeab696d1d48069ae631a1 /Documentation
parent5260562754c0aa4b95eebb1f851eaccce7286365 (diff)
parentb11e7b3f3b56119194234085d42a633ceabd6aba (diff)
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Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/staging: (24 commits) hwmon: lis3: Release resources in case of failure hwmon: lis3: Short explanations of platform data fields hwmon: lis3: Enhance lis3 selftest with IRQ line test hwmon: lis3: use block read to access data registers hwmon: lis3: Adjust fuzziness for 8 bit device hwmon: lis3: New parameters to platform data hwmon: lis3: restore axis enabled bits hwmon: lis3: Power on corrections hwmon: lis3: Update coordinates at polled device open hwmon: lis3: Cleanup interrupt handling hwmon: lis3: regulator control hwmon: lis3: pm_runtime support Kirkwood: add fan support for Network Space Max v2 hwmon: add generic GPIO fan driver hwmon: (coretemp) fix reading of microcode revision (v2) hwmon: ({core, pkg, via-cpu}temp) remove unnecessary CONFIG_HOTPLUG_CPU ifdefs hwmon: (pkgtemp) align driver initialization style with coretemp hwmon: LTC4261 Hardware monitoring driver hwmon: (lis3) add axes module parameter for custom axis-mapping hwmon: (hp_accel) Add HP Mini 510x family support ...
Diffstat (limited to 'Documentation')
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diff --git a/Documentation/hwmon/ltc4261 b/Documentation/hwmon/ltc4261
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+Kernel driver ltc4261
+=====================
+
+Supported chips:
+ * Linear Technology LTC4261
+ Prefix: 'ltc4261'
+ Addresses scanned: -
+ Datasheet:
+ http://cds.linear.com/docs/Datasheet/42612fb.pdf
+
+Author: Guenter Roeck <guenter.roeck@ericsson.com>
+
+
+Description
+-----------
+
+The LTC4261/LTC4261-2 negative voltage Hot Swap controllers allow a board
+to be safely inserted and removed from a live backplane.
+
+
+Usage Notes
+-----------
+
+This driver does not probe for LTC4261 devices, since there is no register
+which can be safely used to identify the chip. You will have to instantiate
+the devices explicitly.
+
+Example: the following will load the driver for an LTC4261 at address 0x10
+on I2C bus #1:
+$ modprobe ltc4261
+$ echo ltc4261 0x10 > /sys/bus/i2c/devices/i2c-1/new_device
+
+
+Sysfs entries
+-------------
+
+Voltage readings provided by this driver are reported as obtained from the ADC
+registers. If a set of voltage divider resistors is installed, calculate the
+real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the
+value of the divider resistor against the measured voltage and R2 is the value
+of the divider resistor against Ground.
+
+Current reading provided by this driver is reported as obtained from the ADC
+Current Sense register. The reported value assumes that a 1 mOhm sense resistor
+is installed. If a different sense resistor is installed, calculate the real
+current by dividing the reported value by the sense resistor value in mOhm.
+
+The chip has two voltage sensors, but only one set of voltage alarm status bits.
+In many many designs, those alarms are associated with the ADIN2 sensor, due to
+the proximity of the ADIN2 pin to the OV pin. ADIN2 is, however, not available
+on all chip variants. To ensure that the alarm condition is reported to the user,
+report it with both voltage sensors.
+
+in1_input ADIN2 voltage (mV)
+in1_min_alarm ADIN/ADIN2 Undervoltage alarm
+in1_max_alarm ADIN/ADIN2 Overvoltage alarm
+
+in2_input ADIN voltage (mV)
+in2_min_alarm ADIN/ADIN2 Undervoltage alarm
+in2_max_alarm ADIN/ADIN2 Overvoltage alarm
+
+curr1_input SENSE current (mA)
+curr1_alarm SENSE overcurrent alarm