Re: [PATCH] serial: 8250: Add support for using platform_device resources

From: Esben Haabendal
Date: Mon May 06 2019 - 11:20:14 EST


"Enrico Weigelt, metux IT consult" <lkml@xxxxxxxxx> writes:

> On 30.04.19 16:04, Esben Haabendal wrote:
>> Allow getting memory resource (mapbase or iobase) as well as irq from
>> platform_device resources.
>>
>> The UPF_DEV_RESOURCES flag must be set for devices where platform_device
>> resources are to be used. When not set, driver behaves as before.
>>
>> This allows use of the serial8250 driver together with devices with
>> resources added by platform_device_add_resources(), such as mfd child
>> devices added with mfd_add_devices().
>
> I like the idea (actually, quite the direction I'd like to go), but
> unfortunately it's more compilicated than that.
>
> Some drivers don't use these fields, eg. 8250 determines the mapsize
> based on several factors, at the time of the mapping is done. That's
> one of the things my patches shall clean up.

Could you take a quick look at my patch again. The patch only changes
the probe method in the serial8250_isa_driver in 8250_core.c file.

So other drivers are not affected by this change.

And with the addition of the new UPF_DEV_RESOURCES flag, no existing
platforms should be affected either.

The patch merely makes it possible to start using plain "serial8250"
driver (serial8250_isa_driver) with standard platform resources, fx. as
implemented by mfd-core.

/Esben