CC: Mika
On Thursday, October 22, 2015 01:05:42 PM Ben Gardner wrote:
> Hi all,
>
> I have a custom Baytrail board with a M24C02 EEPROM attached to I2C bus 3.
> I am using coreboot/SeaBIOS, so I have complete control over the ACPI tables.
> I am using Linux 4.2.3.
>
> I have defined a EEPROM device on I2C3 using I2cSerialBus() and it
> shows up as expected.
>
> Scope (\_SB.PCI0.I2C3) {
> Device (EEP0) {
> Name (_CID, Package() { "24c02" })
> Name (_CRS, ResourceTemplate () {
> I2cSerialBus (0x0057, ControllerInitiated, 400000,
> AddressingMode7Bit, "\\_SB.PCI0.I2C3", 0x00,
> ResourceConsumer,,)
> })
> }
> }
>
> Everything is nearly working, except that acpi_i2c_add_device() is
> using the ACPI name to match the driver, which is "24C02:00".
> The "at42" driver supports the device with the "24c02" alias.
> i2c_match_id() in i2c-core.c uses strcmp() to match the device.
> That obviously doesn't match, as "24c02" != "24C02:00".
>
> When I modified acpi_i2c_add_device() to truncate at the colon and
> convert it to lower case, it matches and works.
>
>
> What is the right way to declare a I2C device in ACPI so that it
> matches existing drivers?
>
>
> For reference only, I included the change I made to get it to work below.
> (Copy/pasted into gmail, so tabs are lost.)
>
> Thanks,
> Ben Gardner
>
> diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
> index c83e4d1..64caddc 100644
> --- a/drivers/i2c/i2c-core.c
> +++ b/drivers/i2c/i2c-core.c
> @@ -144,7 +144,13 @@ static acpi_status
> acpi_i2c_add_device(acpi_handle handle, u32 level,
> return AE_OK;
>
> adev->power.flags.ignore_parent = true;
> - strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type));
> + {
> + const char *dn = dev_name(&adev->dev);
> + int idx;
> + for (idx = 0; idx < sizeof(info.type) - 1 && dn[idx]
> && dn[idx] != ':'; idx++)
> + info.type[idx] = tolower(dn[idx]);
> + }
> if (!i2c_new_device(adapter, &info)) {
> adev->power.flags.ignore_parent = false;
> dev_err(&adapter->dev,
> --
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--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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