On Fri, Oct 23, 2015 at 3:20 AM, Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> 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)
> }
> }
I like this approach, as one change to the driver will support all ACPI devices.
I'll give it a try.
Thanks,
Ben
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