Re: [PATCH V5] dmaengine: Loongson1: Add Loongson1 dmaengine driver

Greg KH
2021-07-20T11:49:24Z

On Tue, Jul 20, 2021 at 05:13:53PM +0530, Vinod Koul wrote:
> On 17-07-21, 19:39, Greg KH wrote:
> > On Sat, Jul 17, 2021 at 08:09:45PM +0530, Vinod Koul wrote:
> > > On 17-07-21, 18:57, Kelvin Cheung wrote:
> > > > Vinod Koul <vkoul@kernel.org> 于2021年7月14日周三 下午1:14写道：
> > > > >
> > > > > On 04-07-21, 23:33, Keguang Zhang wrote:
> > > > >
> > > > > > +static struct platform_driver ls1x_dma_driver = {
> > > > > > + .probe = ls1x_dma_probe,
> > > > > > + .remove = ls1x_dma_remove,
> > > > > > + .driver = {
> > > > > > + .name = "ls1x-dma",
> > > > > > + },
> > > > > > +};
> > > > > > +
> > > > > > +module_platform_driver(ls1x_dma_driver);
> > > > >
> > > > > so my comment was left unanswered, who creates this device!
> > > >
> > > > Sorry!
> > > > This patch will create the device: https://patchwork.kernel.org/patch/12281691
> > >
> > > Greg, looks like the above patch creates platform devices in mips, is
> > > that the right way..?
> >
> > I do not understand, what exactly is the question?
>
> So this patch was adding Loongson1 dmaengine driver which is a platform
> device. I asked about the platform device and was told that [1] creates
> the platform device. I am not sure if that is the recommended way given
> that you have been asking people to not use platform devices.

Yes, but this link:

> [1]: https://patchwork.kernel.org/patch/12281691

Does look like a "real" platform device in that you have fixed resources
for the device and no way to discover it on your own.

But why are you not using DT for this? That looks like the old platform
data files.

thanks,

greg k-h