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Diffstat (limited to 'Documentation/hwmon/hwmon-kernel-api.txt')
| -rw-r--r-- | Documentation/hwmon/hwmon-kernel-api.txt | 24 |
1 files changed, 16 insertions, 8 deletions
diff --git a/Documentation/hwmon/hwmon-kernel-api.txt b/Documentation/hwmon/hwmon-kernel-api.txt index eb7a78aebb38..8bdefb41be30 100644 --- a/Documentation/hwmon/hwmon-kernel-api.txt +++ b/Documentation/hwmon/hwmon-kernel-api.txt @@ -299,17 +299,25 @@ functions is used. The header file linux/hwmon-sysfs.h provides a number of useful macros to declare and use hardware monitoring sysfs attributes. -In many cases, you can use the exsting define DEVICE_ATTR to declare such -attributes. This is feasible if an attribute has no additional context. However, -in many cases there will be additional information such as a sensor index which -will need to be passed to the sysfs attribute handling function. +In many cases, you can use the exsting define DEVICE_ATTR or its variants +DEVICE_ATTR_{RW,RO,WO} to declare such attributes. This is feasible if an +attribute has no additional context. However, in many cases there will be +additional information such as a sensor index which will need to be passed +to the sysfs attribute handling function. SENSOR_DEVICE_ATTR and SENSOR_DEVICE_ATTR_2 can be used to define attributes which need such additional context information. SENSOR_DEVICE_ATTR requires one additional argument, SENSOR_DEVICE_ATTR_2 requires two. -SENSOR_DEVICE_ATTR defines a struct sensor_device_attribute variable. -This structure has the following fields. +Simplified variants of SENSOR_DEVICE_ATTR and SENSOR_DEVICE_ATTR_2 are available +and should be used if standard attribute permissions and function names are +feasible. Standard permissions are 0644 for SENSOR_DEVICE_ATTR[_2]_RW, +0444 for SENSOR_DEVICE_ATTR[_2]_RO, and 0200 for SENSOR_DEVICE_ATTR[_2]_WO. +Standard functions, similar to DEVICE_ATTR_{RW,RO,WO}, have _show and _store +appended to the provided function name. + +SENSOR_DEVICE_ATTR and its variants define a struct sensor_device_attribute +variable. This structure has the following fields. struct sensor_device_attribute { struct device_attribute dev_attr; @@ -320,8 +328,8 @@ You can use to_sensor_dev_attr to get the pointer to this structure from the attribute read or write function. Its parameter is the device to which the attribute is attached. -SENSOR_DEVICE_ATTR_2 defines a struct sensor_device_attribute_2 variable, -which is defined as follows. +SENSOR_DEVICE_ATTR_2 and its variants define a struct sensor_device_attribute_2 +variable, which is defined as follows. struct sensor_device_attribute_2 { struct device_attribute dev_attr; |