Messages in this thread | | | From | Marek Vasut <> | Subject | Re: [PATCH] iio: acpi: Add ACPI0008 Ambient Light Sensor | Date | Thu, 30 Apr 2015 13:30:28 +0200 |
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On Thursday, April 30, 2015 at 01:27:43 PM, Gabriele Mazzotta wrote: > On Thursday 30 April 2015 11:44:36 Marek Vasut wrote: > > On Wednesday, April 29, 2015 at 05:36:32 PM, Gabriele Mazzotta wrote: > > [...] > > > > > > > I'm sorry, I've just noticed that I haven't changed the value of > > > > > realbits in acpi_als_channels. This makes me wonder what would be > > > > > the proper value, given that this is a generic driver and all the > > > > > information I have are those in the ACPI specification (which > > > > > states what I reported here above). > > > > > > > > > > Should I just set realbits to 32? > > > > > > > > I believe the ALS reports only 16bit signel value, no ? > > > > My observation with a strong coherent light source is that > > > > the saturated sensor reported 0xffff . > > > > > > Probably it's the same for me. I couldn't get to the point where > > > ALI reports 0xffff, just really close, I will have to try with some > > > stronger lights. However, looking at my ACPI table, I can see that > > > the value returned by _ALI is just the composition of two 8 bits > > > variables put side by side, so yes, I can say that even on my system > > > it's a 16bit value. > > > > What kind of hardware are you testing this on ?
Hi!
> Dell XPS13 9333.
Cool, even better :)
I tested it on the following hardware: Acer W500 Retina MacBook Pro 10,1 MacBook Air (I don't know the revision, sorry)
> > > The problem here is that I'm not sure we can assume this as true in > > > general since the ACPI specification doesn't say anything. > > > > Maybe someone more knowledgable can speak up. > > I'm looking at some documentation from Microsoft [1] on how to use these > sensors in Windows and values as high as 100,000 lux are mentioned.
I see, thank you for investigating !
> [1] > https://msdn.microsoft.com/en-us/library/windows/hardware/dn613948%28v=vs. > 85%29.aspx
Best regards, Marek Vasut
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