path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-14 14:57:58 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-14 14:57:58 -0700
commitd310ad0c9d6354affc8abdcfb189ae1a434f18ae (patch)
treeb4daa9dc377e30087b6433a6ab95cc9ef0768528 /Documentation
parentc29c08b59875fe053471cf9eb66f8cfef39bc509 (diff)
parentf279941863f0d39fa8285b84449b52b8286a254b (diff)
Merge branch 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging: (22 commits) hwmon: (via-cputemp) Remove bogus "SHOW" global variable hwmon: jc42 depends on I2C hwmon: (pc87427) Add a maintainer hwmon: (pc87427) Move sysfs file removal to a separate function hwmon: (pc87427) Add temperature monitoring support hwmon: (pc87427) Add support for the second logical device hwmon: (pc87427) Add support for manual fan speed control hwmon: (pc87427) Minor style cleanups hwmon: (pc87427) Handle disabled fan inputs properly hwmon: (w83627ehf) Add support for W83667HG-B hwmon: (w83627ehf) Driver cleanup hwmon: Add driver for SMSC EMC2103 temperature monitor and fan controller hwmon: Remove in[0-*]_fault from sysfs-interface hwmon: Add 4 current alarm/beep attributes to sysfs-interface hwmon: Add 3 critical limit attributes to sysfs-interface hwmon: (asc7621) Clean up and improve detect function hwmon: (it87) Export labels for internal sensors hwmon: (lm75) Add suspend/resume feature hwmon: (emc1403) Add power support hwmon: (ltc4245) Expose all GPIO pins as analog voltages ...
Diffstat (limited to 'Documentation')
5 files changed, 114 insertions, 14 deletions
diff --git a/Documentation/hwmon/emc2103 b/Documentation/hwmon/emc2103
new file mode 100644
index 00000000000..a12b2c12714
--- /dev/null
+++ b/Documentation/hwmon/emc2103
@@ -0,0 +1,33 @@
+Kernel driver emc2103
+Supported chips:
+ * SMSC EMC2103
+ Addresses scanned: I2C 0x2e
+ Prefix: 'emc2103'
+ Datasheet: Not public
+ Steve Glendinning <steve.glendinning@smsc.com>
+The Standard Microsystems Corporation (SMSC) EMC2103 chips
+contain up to 4 temperature sensors and a single fan controller.
+Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
+triggered if the rotation speed has dropped below a programmable limit. Fan
+readings can be divided by a programmable divider (1, 2, 4 or 8) to give
+the readings more range or accuracy. Not all RPM values can accurately be
+represented, so some rounding is done. With a divider of 1, the lowest
+representable value is 480 RPM.
+This driver supports RPM based control, to use this a fan target
+should be written to fan1_target and pwm1_enable should be set to 3.
+The 2103-2 and 2103-4 variants have a third temperature sensor, which can
+be connected to two anti-parallel diodes. These values can be read
+as temp3 and temp4. If only one diode is attached to this channel, temp4
+will show as "fault". The module parameter "apd=0" can be used to suppress
+this 4th channel when anti-parallel diodes are not fitted.
diff --git a/Documentation/hwmon/ltc4245 b/Documentation/hwmon/ltc4245
index 86b5880d850..b478b086496 100644
--- a/Documentation/hwmon/ltc4245
+++ b/Documentation/hwmon/ltc4245
@@ -72,9 +72,31 @@ in6_min_alarm 5v output undervoltage alarm
in7_min_alarm 3v output undervoltage alarm
in8_min_alarm Vee (-12v) output undervoltage alarm
-in9_input GPIO voltage data
+in9_input GPIO voltage data (see note 1)
+in10_input GPIO voltage data (see note 1)
+in11_input GPIO voltage data (see note 1)
power1_input 12v power usage (mW)
power2_input 5v power usage (mW)
power3_input 3v power usage (mW)
power4_input Vee (-12v) power usage (mW)
+Note 1
+If you have NOT configured the driver to sample all GPIO pins as analog
+voltages, then the in10_input and in11_input sysfs attributes will not be
+created. The driver will sample the GPIO pin that is currently connected to the
+ADC as an analog voltage, and report the value in in9_input.
+If you have configured the driver to sample all GPIO pins as analog voltages,
+then they will be sampled in round-robin fashion. If userspace reads too
+slowly, -EAGAIN will be returned when you read the sysfs attribute containing
+the sensor reading.
+The LTC4245 chip can be configured to sample all GPIO pins with two methods:
+1) platform data -- see include/linux/i2c/ltc4245.h
+2) OF device tree -- add the "ltc4245,use-extra-gpios" property to each chip
+The default mode of operation is to sample a single GPIO pin.
diff --git a/Documentation/hwmon/pc87427 b/Documentation/hwmon/pc87427
index db5cc1227a8..8fdd08c9e48 100644
--- a/Documentation/hwmon/pc87427
+++ b/Documentation/hwmon/pc87427
@@ -18,10 +18,11 @@ Description
The National Semiconductor Super I/O chip includes complete hardware
monitoring capabilities. It can monitor up to 18 voltages, 8 fans and
-6 temperature sensors. Only the fans are supported at the moment.
+6 temperature sensors. Only the fans and temperatures are supported at
+the moment, voltages aren't.
-This chip also has fan controlling features, which are not yet supported
-by this driver either.
+This chip also has fan controlling features (up to 4 PWM outputs),
+which are partly supported by this driver.
The driver assumes that no more than one chip is present, which seems
@@ -36,3 +37,23 @@ signal. Speeds down to 83 RPM can be measured.
An alarm is triggered if the rotation speed drops below a programmable
limit. Another alarm is triggered if the speed is too low to be measured
(including stalled or missing fan).
+Fan Speed Control
+Fan speed can be controlled by PWM outputs. There are 4 possible modes:
+always off, always on, manual and automatic. The latter isn't supported
+by the driver: you can only return to that mode if it was the original
+setting, and the configuration interface is missing.
+Temperature Monitoring
+The PC87427 relies on external sensors (following the SensorPath
+standard), so the resolution and range depend on the type of sensor
+connected. The integer part can be 8-bit or 9-bit, and can be signed or
+not. I couldn't find a way to figure out the external sensor data
+temperature format, so user-space adjustment (typically by a factor 2)
+may be required.
diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface
index d4e2917c6f1..ff45d1f837c 100644
--- a/Documentation/hwmon/sysfs-interface
+++ b/Documentation/hwmon/sysfs-interface
@@ -107,10 +107,24 @@ in[0-*]_min Voltage min value.
Unit: millivolt
+in[0-*]_lcrit Voltage critical min value.
+ Unit: millivolt
+ RW
+ If voltage drops to or below this limit, the system may
+ take drastic action such as power down or reset. At the very
+ least, it should report a fault.
in[0-*]_max Voltage max value.
Unit: millivolt
+in[0-*]_crit Voltage critical max value.
+ Unit: millivolt
+ RW
+ If voltage reaches or exceeds this limit, the system may
+ take drastic action such as power down or reset. At the very
+ least, it should report a fault.
in[0-*]_input Voltage input value.
Unit: millivolt
@@ -284,7 +298,7 @@ temp[1-*]_input Temperature input value.
Unit: millidegree Celsius
-temp[1-*]_crit Temperature critical value, typically greater than
+temp[1-*]_crit Temperature critical max value, typically greater than
corresponding temp_max values.
Unit: millidegree Celsius
@@ -296,6 +310,11 @@ temp[1-*]_crit_hyst
from the critical value.
+temp[1-*]_lcrit Temperature critical min value, typically lower than
+ corresponding temp_min values.
+ Unit: millidegree Celsius
+ RW
Temperature offset which is added to the temperature reading
by the chip.
@@ -344,9 +363,6 @@ Also see the Alarms section for status flags associated with temperatures.
* Currents *
-Note that no known chip provides current measurements as of writing,
-so this part is theoretical, so to say.
curr[1-*]_max Current max value
Unit: milliampere
@@ -471,6 +487,7 @@ limit-related alarms, not both. The driver should just reflect the hardware
Channel alarm
@@ -482,6 +499,8 @@ OR
@@ -497,7 +516,6 @@ to notify open diodes, unconnected fans etc. where the hardware
supports it. When this boolean has value 1, the measurement for that
channel should not be trusted.
Input fault condition
@@ -513,6 +531,7 @@ beep_enable Master beep enable
Channel beep
diff --git a/Documentation/hwmon/w83627ehf b/Documentation/hwmon/w83627ehf
index b7e42ec4b26..13d556112fc 100644
--- a/Documentation/hwmon/w83627ehf
+++ b/Documentation/hwmon/w83627ehf
@@ -20,6 +20,10 @@ Supported chips:
Prefix: 'w83667hg'
Addresses scanned: ISA address retrieved from Super I/O registers
Datasheet: not available
+ * Winbond W83667HG-B
+ Prefix: 'w83667hg'
+ Addresses scanned: ISA address retrieved from Super I/O registers
+ Datasheet: Available from Nuvoton upon request
Jean Delvare <khali@linux-fr.org>
@@ -32,8 +36,8 @@ Description
This driver implements support for the Winbond W83627EHF, W83627EHG,
-W83627DHG, W83627DHG-P and W83667HG super I/O chips. We will refer to them
-collectively as Winbond chips.
+W83627DHG, W83627DHG-P, W83667HG and W83667HG-B super I/O chips.
+We will refer to them collectively as Winbond chips.
The chips implement three temperature sensors, five fan rotation
speed sensors, ten analog voltage sensors (only nine for the 627DHG), one
@@ -68,14 +72,15 @@ follows:
temp1 -> pwm1
temp2 -> pwm2
temp3 -> pwm3
-prog -> pwm4 (not on 667HG; the programmable setting is not supported by
- the driver)
+prog -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not
+ supported by the driver)
/sys files
name - this is a standard hwmon device entry. For the W83627EHF and W83627EHG,
- it is set to "w83627ehf" and for the W83627DHG it is set to "w83627dhg"
+ it is set to "w83627ehf", for the W83627DHG it is set to "w83627dhg",
+ and for the W83667HG it is set to "w83667hg".
pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range:
0 (stop) to 255 (full)