Re: [PATCH v4,4/4] drivers: uio: new driver for fsl_85xx_cache_sram

[王文虎]

>On Fri, 2020-04-17 at 09:42 +0200, Greg KH wrote:>> On Thu, Apr 16, 2020 at 11:58:29PM -0500, Scott Wood wrote:
>> > On Fri, 2020-04-17 at 10:31 +0800, 王文虎 wrote:
>> > > Sounds it is. And does the modification below fit well?
>> > > ---
>> > > -static const struct of_device_id uio_mpc85xx_l2ctlr_of_match[] = {
>> > > -       {       .compatible = "uio,mpc85xx-cache-sram", },
>> > > -       {},
>> > > +#ifdef CONFIG_OF
>> > > +static struct of_device_id uio_fsl_85xx_cache_sram_of_match[] = {
>> > > +       { /* This is filled with module_parm */ },
>> > > +       { /* Sentinel */ },
>> > >  };
>> > > +MODULE_DEVICE_TABLE(of, uio_fsl_85xx_cache_sram_of_match);
>> > > +module_param_string(of_id,
>> > > uio_fsl_85xx_cache_sram_of_match[0].compatible,
>> > > +                           sizeof(uio_fsl_85xx_cache_sram_of_match[0].c
>> > > ompa
>> > > tible), 0);
>> > > +MODULE_PARM_DESC(of_id, "platform device id to be handled by cache-
>> > > sram-
>> > > uio");
>> > > +#endif
>> > 
>> > No.  The point is that you wouldn't be configuring this with the device
>> > tree
>> > at all.
>> 
>> Wait, why not?  Don't force people to use module parameters, that is
>> crazy.  DT describes the hardware involved, if someone wants to bind to
>> a specific range of memory, as described by DT, why can't they do so?
>
>Yes, DT describes the hardware, and as I've said a couple times already, this
>isn't hardware description.
>
>I'm not forcing people to use module parameters.  That was a least-effort
>suggestion to avoid abusing the DT.  I later said I'd try to come up with a
>patch that allocates regions dynamically (and most likely doesn't use UIO at
>all).
>
>> I can understand not liking the name "uio" in a dt tree, but there's no
>> reason that DT can not describe what a driver binds to here.
>
>The DT already describes this hardware, and there is already code that binds
>to it.  This patch is trying to add a second node for it with configuration.
>
Hi, Scott, Greg,
Seems like no balance here. How about I implement a driver of uio including
the l2ctrl and cache_sram related implementations?
And this way, the driver would be a hardware level driver and targeted for uio.

Regards,
Wenhu