Re: [PATCH v3 2/4] ACPI / scan: Create platform device for fwnodes with multiple i2c devices

Hans de Goede
2018-08-07T11:29:33Z

Hi,

On 07-08-18 13:19, Andy Shevchenko wrote:
> On Tue, 2018-08-07 at 10:05 +0200, Hans de Goede wrote:
>> Some devices have multiple I2cSerialBus resources and for things to
>> work
>> an i2c-client must be instantiated for each, each with its own
>> i2c_device_id.
>>
>> Normally we only instantiate an i2c-client for the first resource,
>> using
>> the ACPI HID as id.
>>
>> This commit adds a list of HIDs of devices, which need multiple i2c-
>> clients
>> instantiated from a single fwnode, to
>> acpi_device_enumeration_by_parent and
>> makes acpi_device_enumeration_by_parent return false for these devices
>> so
>> that a platform device will be instantiated.
>>
>> This allows the drivers/platform/x86/i2c-multi-instantiate.c driver,
>> which
>> knows which i2c_device_id to use for each resource, to bind to the
>> fwnode
>> and initiate an i2c-client for each resource.
>>
>
>> + /*
>> + * These devices have multiple I2cSerialBus resources and an
>> i2c-client
>> + * must be instantiated for each, each with its own
>> i2c_device_id.
>> + * Normally we only instantiate an i2c-client for the first
>> resource,
>> + * using the ACPI HID as id. These special cases are handled by
>> the
>> + * drivers/platform/x86/i2c-multi-instantiate.c driver, which
>> knows
>> + * which i2c_device_id to use for each resource.
>> + */
>> + static const struct acpi_device_id i2c_multi_instantiate_ids[] =
>> {
>> + {"BSG1160", 0},
>> + {"", 0},
>> + };
>
> Style nits:
> - can we move it outside of function?

Sure, but there are 2 existing users of an array of acpi_device_id-s
combined with an acpi_match_device_ids() call and both have the array
inside the function, so for consistency it seems better to keep it
where it is.

> - terminator better without comma

Agreed, will fix for v4.

> - is this existing style in the file and / or files in this folder for
> IDs? (I mean unnecessary 0:s and empty string?

It seems that all variants one can come up with are already used inside
this single file.

I agree that less is more, so I will change this to:

static const struct acpi_device_id i2c_multi_instantiate_ids[] = {
{"BSG1160", },
{}
};

For v4.

Regards,

Hans