• Hans de Goede's avatar
    ACPI / utils: Add new acpi_dev_present helper · 8661423e
    Hans de Goede authored
    acpi_dev_found just iterates over all ACPI-ids and sees if one matches.
    This means that it will return true for devices which are in the DSDT
    but disabled (their _STA method returns 0).
    
    For some drivers it is useful to be able to check if a certain HID
    is not only present in the namespace, but also actually present as in
    acpi_device_is_present() will return true for the device. For example
    because if a certain device is present then the driver will want to use
    an extcon or IIO ADC channel provided by that device.
    
    This commit adds a new acpi_dev_present helper which drivers can use
    to this end.
    
    Like acpi_dev_found, acpi_dev_present take a HID as argument, but
    it also has 2 extra optional arguments to only check for an ACPI
    device with a specific UID and/or HRV value. This makes it more
    generic and allows it to replace custom code doing similar checks
    in several places.
    
    Arguably acpi_dev_present is what acpi_dev_found should have been, but
    there are too many users to just change acpi_dev_found without the risk
    of breaking something.
    Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
    Reviewed-by: default avatarLukas Wunner <lukas@wunner.de>
    Reviewed-by: default avatarMika Westerberg <mika.westerberg@linux.intel.com>
    Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
    8661423e
utils.c 20.8 KB