From cd4e96c5dd4a72bdc54ea9981e02465708c204d3 Mon Sep 17 00:00:00 2001 From: Andre Prendel Date: Mon, 15 Jun 2009 18:39:49 +0200 Subject: [PATCH] hwmon: (tmp401) Add documentation Documentation for the tmp401 driver. The documentation describes the tmp401 driver and the supported Texas Instruments TMP401 and TMP411 temperature sensor chips. Further documentation for new sysfs attributes supported by this driver is added to Documentation/hwmon/sysfs-interface. Signed-off-by: Andre Prendel Acked-by: Hans de Goede Signed-off-by: Jean Delvare --- Documentation/hwmon/sysfs-interface | 19 +++++++++++++ Documentation/hwmon/tmp401 | 42 +++++++++++++++++++++++++++++ 2 files changed, 61 insertions(+) create mode 100644 Documentation/hwmon/tmp401 diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface index 004ee161721..dcbd502c879 100644 --- a/Documentation/hwmon/sysfs-interface +++ b/Documentation/hwmon/sysfs-interface @@ -70,6 +70,7 @@ are interpreted as 0! For more on how written strings are interpreted see the [0-*] denotes any positive number starting from 0 [1-*] denotes any positive number starting from 1 RO read only value +WO write only value RW read/write value Read/write values may be read-only for some chips, depending on the @@ -295,6 +296,24 @@ temp[1-*]_label Suggested temperature channel label. user-space. RO +temp[1-*]_lowest + Historical minimum temperature + Unit: millidegree Celsius + RO + +temp[1-*]_highest + Historical maximum temperature + Unit: millidegree Celsius + RO + +temp[1-*]_reset_history + Reset temp_lowest and temp_highest + WO + +temp_reset_history + Reset temp_lowest and temp_highest for all sensors + WO + Some chips measure temperature using external thermistors and an ADC, and report the temperature measurement as a voltage. Converting this voltage back to a temperature (or the other way around for limits) requires diff --git a/Documentation/hwmon/tmp401 b/Documentation/hwmon/tmp401 new file mode 100644 index 00000000000..9fc44724921 --- /dev/null +++ b/Documentation/hwmon/tmp401 @@ -0,0 +1,42 @@ +Kernel driver tmp401 +==================== + +Supported chips: + * Texas Instruments TMP401 + Prefix: 'tmp401' + Addresses scanned: I2C 0x4c + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp401.html + * Texas Instruments TMP411 + Prefix: 'tmp411' + Addresses scanned: I2C 0x4c + Datasheet: http://focus.ti.com/docs/prod/folders/print/tmp411.html + +Authors: + Hans de Goede + Andre Prendel + +Description +----------- + +This driver implements support for Texas Instruments TMP401 and +TMP411 chips. These chips implements one remote and one local +temperature sensor. Temperature is measured in degrees +Celsius. Resolution of the remote sensor is 0.0625 degree. Local +sensor resolution can be set to 0.5, 0.25, 0.125 or 0.0625 degree (not +supported by the driver so far, so using the default resolution of 0.5 +degree). + +The driver provides the common sysfs-interface for temperatures (see +/Documentation/hwmon/sysfs-interface under Temperatures). + +The TMP411 chip is compatible with TMP401. It provides some additional +features. + +* Minimum and Maximum temperature measured since power-on, chip-reset + + Exported via sysfs attributes tempX_lowest and tempX_highest. + +* Reset of historical minimum/maximum temperature measurements + + Exported via sysfs attribute temp_reset_history. Writing 1 to this + file triggers a reset.