Re: [PATCH V2 2/3] dmaengine: qcom_hidma: add support for the new revision

Robin Murphy
2017-11-10T14:17:21Z

On 10/11/17 14:03, Sinan Kaya wrote:
> +linux-acpi, +Rafael for context
>
> On 11/8/2017 12:51 PM, Robin Murphy wrote:
>> Apologies if I wasn't very clear, but what I meant to imply by dropping the of_device_get_match_data() hint was to follow one of the common patterns where you either just have some version token:
>>
>>     enum foo_ver {
>>         FOO_V1,
>>         ...
>>     }
>>
>>     struct acpi_device_id foo_acpi_ids[] = {
>>         { "_FOO0001", FOO_V1 },
>>         ...
>>     }
>>
>>     struct of_device_id foo_of_match[] = {
>>         { .compatible = "foo,v1", .data = (void *)FOO_V1 },
>>         ...
>>     }
>>
>>     int foo_probe(struct device *dev) {
>>         ...
>>         foodev->version = (enum foo_ver)
>>                 of_device_get_match_data(&dev->of_node)
>>         ...
>>     }
>>
>>     int foo_reset(struct foodev *foodev) {
>>         if (foodev->version == FOO_V1)
>>             writel(0, foodev->base + 0x20);
>>         else
>>             writel(0, foodev->base + 0x30);
>>     }
>
> I did post v3 with this approach. However, I could not really find a ACPI function that
> returns the driver data very similar to of_device_get_match_data(). The only thing
> that is closer is acpi_match_device().

Yeah, I left the "follow the status quo and open-code it" part out of
the above example for brevity ;)

Probably 95% of the calls to acpi_match_device() are only doing so to
retrieve the driver_data, so the helper could provide scope for further
cleanup if anyone wants, too.

> I introduced this new function as part of the v3 series.
>
> Let me know if I'm missing something.
v3 looks good, thanks for persevering - I'll leave the rest up to Vinod
and Rafael.

Cheers,
Robin.