Documentation/hwmon/ltc4245.rst

Source file repositories/reference/linux-study-clean/Documentation/hwmon/ltc4245.rst

File Facts

System
Linux kernel
Corpus path
Documentation/hwmon/ltc4245.rst
Extension
.rst
Size
3491 bytes
Lines
112
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

Kernel driver ltc4245
=====================

Supported chips:

  * Linear Technology LTC4245

    Prefix: 'ltc4245'

    Addresses scanned: 0x20-0x3f

    Datasheet:

	http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1140,P19392,D13517

Author: Ira W. Snyder <iws@ovro.caltech.edu>


Description
-----------

The LTC4245 controller allows a board to be safely inserted and removed
from a live backplane in multiple supply systems such as CompactPCI and
PCI Express.


Usage Notes
-----------

This driver does not probe for LTC4245 devices, due to the fact that some
of the possible addresses are unfriendly to probing. You will have to
instantiate the devices explicitly.

Example: the following will load the driver for an LTC4245 at address 0x23
on I2C bus #1::

	$ modprobe ltc4245
	$ echo ltc4245 0x23 > /sys/bus/i2c/devices/i2c-1/new_device


Sysfs entries
-------------

The LTC4245 has built-in limits for over and under current warnings. This
makes it very likely that the reference circuit will be used.

This driver uses the values in the datasheet to change the register values
into the values specified in the sysfs-interface document. The current readings
rely on the sense resistors listed in Table 2: "Sense Resistor Values".

======================= =======================================================
in1_input		12v input voltage (mV)
in2_input		5v  input voltage (mV)
in3_input		3v  input voltage (mV)
in4_input		Vee (-12v) input voltage (mV)

in1_min_alarm		12v input undervoltage alarm
in2_min_alarm		5v  input undervoltage alarm
in3_min_alarm		3v  input undervoltage alarm
in4_min_alarm		Vee (-12v) input undervoltage alarm

curr1_input		12v current (mA)
curr2_input		5v  current (mA)
curr3_input		3v  current (mA)
curr4_input		Vee (-12v) current (mA)

curr1_max_alarm		12v overcurrent alarm
curr2_max_alarm		5v  overcurrent alarm
curr3_max_alarm		3v  overcurrent alarm
curr4_max_alarm		Vee (-12v) overcurrent alarm

Annotation

Implementation Notes