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Ambient light sensor RRS feed

  • Question

  • Hi there,

    I am confused about Ambient light sensor implementation. I look up the ACPI spec, BIOS needs to declare HID in AML, and _ALI with _ALR(Required). there are two ways to connect ALS. 

    1. ALS is connected by LPC, BIOS knows which services needs to be served by SCI event when light changed ,   _AML and _ALI will be used by ACPI driver .

    2. ALS is connected with USB controller, NOT LPC, but no one can knows that light has been changed already(cuz             no any SCI is signaled), so I have no ideal, who will notify OS or ACPI driver to call _AML and _AMI method                 when light is changed? 

                 I guess it is inbox driver in charge of all of task, but I'm not sure, it's following steps.

    a.) ALS detect that light is changed.

    b.) To notify Inbox driver, inbox driver to find a suitable value(brightness level) reports ALS. onthe other                          hand, BIOS doesn't need _AML and _ALI, am I right?  


    Friday, June 15, 2012 10:19 AM

All replies

  • This article has a link to the white paper on developing an ambient light sensor.

    This posting is provided "AS IS" with no warranties, and confers no rights.

    Friday, June 15, 2012 9:16 PM