Re: [PATCH 3/8 v4] dma: k3dma: Upgrade k3dma driver to support hisi_asp_dma hardware

[John Stultz]

On Sun, Jan 20, 2019 at 3:12 AM Vinod Koul <vkoul@xxxxxxxxxx> wrote:
>
> On 16-01-19, 09:10, John Stultz wrote:
> > From: Youlin Wang <wwx575822@xxxxxxxxxxxxxxxxxxxx>
> >
> > On the hi3660 hardware there are two (at least) DMA controllers,
> > the DMA-P (Peripherial DMA) and the DMA-A (Audio DMA). The
>                     ^^^
> typo

Thanks so much for the review!

Fixed!

> > +
> > +#define K3_FLAG_NOCLK  (1<<0)
>
> why not use BIT()
>
> space between two please

Fixed.

> > +static const struct k3dma_soc_data k3_v1_dma_data = {
> > +     .flags = 0,
> > +};
>
> So basically this is default right, do we need to set dma_data and not
> assume default..

I'm not sure I fully understand you here. Basically I'm just creating
a per-variant data structure. The k3_v1_dma_data isn't really the
default, but is the first variant supported. There may be future
variants that cause some new flag that the k3_v3_dma_data may need to
set. But for now that variant doesn't have any flags set.


> > +
> > +static const struct k3dma_soc_data asp_v1_dma_data = {
> > +     .flags = K3_FLAG_NOCLK,
> > +};
> > +
> >  static const struct of_device_id k3_pdma_dt_ids[] = {
> > -     { .compatible = "hisilicon,k3-dma-1.0", },
> > +     { .compatible = "hisilicon,k3-dma-1.0",
> > +       .data = &k3_v1_dma_data
> > +     },
> > +     { .compatible = "hisilicon,hisi-pcm-asp-dma-1.0",
> > +       .data = &asp_v1_dma_data
> > +     },
> >       {}
> >  };
> >  MODULE_DEVICE_TABLE(of, k3_pdma_dt_ids);
> > @@ -810,6 +830,7 @@ static struct dma_chan *k3_of_dma_simple_xlate(struct of_phandle_args *dma_spec,
> >
> >  static int k3_dma_probe(struct platform_device *op)
> >  {
> > +     const struct k3dma_soc_data *soc_data;
> >       struct k3_dma_dev *d;
> >       const struct of_device_id *of_id;
> >       struct resource *iores;
> > @@ -823,6 +844,10 @@ static int k3_dma_probe(struct platform_device *op)
> >       if (!d)
> >               return -ENOMEM;
> >
> > +     soc_data = device_get_match_data(&op->dev);
> > +     if (!soc_data)
> > +             return -EINVAL;
>
> So this is not optional, either ways fine by me :)

I think this way makes sense, but maybe I'm missing a better alternative?

Do let me know if there's an example you'd rather I follow.

Thanks so much again for the review!
-john