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

From: Vinod Koul
Date: Tue Jul 20 2021 - 08:18:32 EST


On 20-07-21, 13:48, Greg KH wrote:
> 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@xxxxxxxxxx> 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.

Apparently I was told that this platform does not use DT :( Looking at
it it should.. Maybe Kelvin can explain why..

--
~Vinod