From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dustin Byford <dustin@cumulusnetworks.com>
Subject: Re: ACPI: Can I use I2cSerialBus with a PCI I2C controller?
Date: Tue, 27 Oct 2015 14:11:11 -0700
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To: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Ben Gardner <gardner.ben@gmail.com>, linux-acpi@vger.kernel.org

Hi Mika,

On Fri Oct 23 11:20, Mika Westerberg wrote:

> You should either use proper _HID/_CID for the device or put "PRP0001"
> to the _HID and let the match happen with DT .compatible strings. I've
> attached a hack that I use locally.

I have a similar hack over here.  I have a question though:

> The corresponding ASL fragment would look like:
> 
> 
>         Device (AT24)
>         {
>             Name (_HID, "PRP0001")
> 
>             Method (_CRS, 0, Serialized) {
>                 Name (UBUF, ResourceTemplate () {
>                     I2cSerialBus (0x50, ControllerInitiated, 0x00061A80,
>                         AddressingMode7Bit, "\\_SB.I2C6",
>                         0x00, ResourceConsumer)
>                 })
>                 Return (UBUF)
>             }
> 
>             Name (_DSD, Package () {
>                 ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
>                 Package () {
>                     Package () {"compatible", "atmel,24c02"},

The "c02" in 24c02 also indicates the size.  I've always found it a
little awkward when you could have a compatible string that disagrees
with firmware properties.  Should we do something about that?

For example, is the more generic string, "atmel,at24" better?  I'm not
sure I like that approach in general, but it works well for the at24
devices.  at25 does it the same way.

>                     Package () {"size", 256},
>                     Package () {"pagesize", 32},
>                     Package () {"abs-value", 1},
>                 },
>             })
> 
>             Method (_STA, 0, NotSerialized)
>             {
>                 Return (0xF)
>             }
>         }

		--Dustin