• Lance Ortiz's avatar
    ACPI: Add new sysfs interface to export device description · d1efe3c3
    Lance Ortiz authored
    Add support to export the device description obtained from the ACPI _STR
    method, if one exists for a device, to user-space via a sysfs interface.
    This new interface provides a standard and platform neutral way for users
    to obtain the description text stored in the ACPI _STR method.  If no
    _STR method exists for the device, no sysfs 'description' file will be
    created.  The 'description' file will be located in the /sys/devices/
    directory using the device's path.
    
    /sys/device/<bus>/<bridge path>/<device path>.../firmware_node/description
    
    Example:
    
    /sys/devices/pci0000:00/0000:00.07.0/0000:0e:00.0/firmware_node/description
    
    It can also be located using the ACPI device path, for example:
    
    /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/PNP0A08:00/device:13/device:15/description
    /sys/devices/LNXSYSTM:00/device:00/ACPI0004:00/ACPI0004:01/ACPI0007:02/description
    
    Execute the 'cat' command on the 'description' file to obtain the
    description string for that device.
    
    This patch also includes documentation describing how the new sysfs
    interface works
    
    Changes from v1-v2 based on comments by Len Brown and Fengguang Wu
    * Removed output "No Description" and leaving a NULL attribute if the
    _STR method failed to evaluate.
    
    * In acpi_device_remove_files() removed the redundent check of
    dev->pnp.str_obj before calling free.  This check triggered a message
    from smatch.
    Signed-off-by: default avatarLance Ortiz <lance.ortiz@hp.com>
    Signed-off-by: default avatarLen Brown <len.brown@intel.com>
    d1efe3c3
sysfs-devices-firmware_node 686 Bytes