On Thu, 2015-12-17 at 15:13 +0000, Måns Rullgård wrote:
> Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> writes:
>
> > On Tue, 2015-12-15 at 23:34 +0000, Måns Rullgård wrote:
> > > Mans Rullgard <mans@xxxxxxxxx> writes:
> > >
> > > > Currently this driver only works with a DesignWare DMA engine
> > > > which
> > > > it
> > > > registers manually using the second "reg" address range and
> > > > interrupt
> > > > number from the DT node.
> > > >
> > > > This patch makes the driver instead use the "dmas" property if
> > > > present,
> > > > otherwise optionally falling back on the old way so existing
> > > > device
> > > > trees can continue to work.
> > > >
> > > > With this change, there is no longer any reason to depend on
> > > > the
> > > > 460EX
> > > > machine type so drop that from Kconfig.
> > > >
> > > > Signed-off-by: Mans Rullgard <mans@xxxxxxxxx>
> > > > ---
> > > > drivers/ata/Kconfig | 10 ++-
> > > > drivers/ata/sata_dwc_460ex.c | 192
> > > > +++++++++++++++++++++++++++--
> > > > --------------
> > > > 2 files changed, 131 insertions(+), 71 deletions(-)
> > >
> > > The corresponding patch for the canyonlands devicetree looks
> > > something
> > > like this. I don't have any such hardware or even a manual, so I
> > > don't
> > > know what values to use for the various required DT properties of
> > > the
> > > DMA controller node, nor can I test it. The SATA driver works
> > > with a
> > > different DMA controller on a Sigma Designs chip.
> > >
> > > diff --git a/arch/powerpc/boot/dts/canyonlands.dts
> > > b/arch/powerpc/boot/dts/canyonlands.dts
> > > index 3dc75de..959f36e 100644
> > > --- a/arch/powerpc/boot/dts/canyonlands.dts
> > > +++ b/arch/powerpc/boot/dts/canyonlands.dts
> > > @@ -190,12 +190,22 @@
> > > /* DMA */ 0x2 &UIC0 0xc
> > > 0x4>;
> > > };
> > >
> > > + DMA0: dma@bffd0800 {
> > > + compatible = "snps,dma-spear1340";
> > > + reg = <4 0xbffd0800 0x400>;
> > > + interrupt-parent = <&UIC3>;
> > > + interrupts = <0x5 0x4>;
> > > + #dma-cells = <3>;
> > > + /* required properties here */
> >
> > You have to move the master assignments and other custom dw_dmac
> > properties. Maybe at some point I will fix that in dw/platform.c.
> >
> > > + };
>
> The current sata_dwc driver calls dw_dma_probe() with null pdata
> which
> causes the dw_dma driver to auto-detect most parameters. It looks
> like
> simply omitting those properties here results in the same thing,
> although in this case dw_dma_parse_dt() leaves a devm-allocated pdata
> struct adrift. Deferring the allocation of that and changing the DT
> binding doc to make these properties optional for auto-detect-capable
> hardware should just work.
Yeah, I would like to allow autoconfiguration in case of DT as well and
translate it to use unified device property API.
> Something like this:
If it works for you, please, submit as a patch. Thanks.
>
> diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
> index 68a4815..f90c465 100644
> --- a/drivers/dma/dw/platform.c
> +++ b/drivers/dma/dw/platform.c
> @@ -103,18 +103,21 @@ dw_dma_parse_dt(struct platform_device *pdev)
> struct device_node *np = pdev->dev.of_node;
> struct dw_dma_platform_data *pdata;
> u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
> + u32 nr_channels;
>
> if (!np) {
> dev_err(&pdev->dev, "Missing DT data\n");
> return NULL;
> }
>
> + if (of_property_read_u32(np, "dma-channels", nr_channels))
> + return NULL;
> +
> pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata),
> GFP_KERNEL);
> if (!pdata)
> return NULL;
>
> - if (of_property_read_u32(np, "dma-channels", &pdata-
> >nr_channels))
> - return NULL;
> + pdata->nr_channels = nr_channels;
>
> if (of_property_read_bool(np, "is_private"))
> pdata->is_private = true;
>
>
--
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Intel Finland Oy
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