On Thu, Oct 22, 2015 at 12:17:58PM -0500, Ben Gardner wrote:
> > The next issue is that the I2C-core isn't matching the device to the
> > "at24" driver, which has the alias "24c02".
> 
> Here is what I found.
> i2c-core is creating the device with the ACPI name "24C02:00".
> The at24 driver uses "24c02" as the alias.
> i2c-code is matching devices to drivers using strcmp().
> 
> Result: no match. ("24c02" != "24C02:00").
> 
> If I modify acpi_i2c_add_device() to cut off the name at the ':' and
> covert to lowercase when populating info.type, it matches and works.
> I must be missing something here, because this would have never worked as-is.
> I'll ask on the I2C mailing list.

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.

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"},
                    Package () {"size", 256},
                    Package () {"pagesize", 32},
                    Package () {"abs-value", 1},
                },
            })

            Method (_STA, 0, NotSerialized)
            {
                Return (0xF)
            }
        }