On Fri, Sep 01, 2017 at 01:31:35AM +0100, Andre Przywara wrote: > Hi, > > On 31/08/17 00:36, Stefan Brüns wrote: > > The A64 SoC has the same dma engine as the H3 (sun8i), with a > > reduced amount of physical channels. Add the proper config data > > and compatible string to support it. > > ... > > > diff --git a/drivers/dma/sun6i-dma.c b/drivers/dma/sun6i-dma.c > > index 5f4eee4513e5..6a17c5d63582 100644 > > --- a/drivers/dma/sun6i-dma.c > > +++ b/drivers/dma/sun6i-dma.c > > @@ -1068,6 +1068,12 @@ static struct sun6i_dma_config sun8i_h3_dma_cfg = { > > .nr_max_vchans = 34, > > .dmac_variant = DMAC_VARIANT_H3, > > }; > > + > > +static struct sun6i_dma_config sun50i_a64_dma_cfg = { > > + .nr_max_channels = 8, > > + .nr_max_requests = 27, > > + .nr_max_vchans = 38, > > + .dmac_variant = DMAC_VARIANT_H3, > > }; > > > > static const struct of_device_id sun6i_dma_match[] = { > > @@ -1075,6 +1081,7 @@ static const struct of_device_id sun6i_dma_match[] = { > > { .compatible = "allwinner,sun8i-a23-dma", .data = &sun8i_a23_dma_cfg }, > > { .compatible = "allwinner,sun8i-a83t-dma", .data = &sun8i_a83t_dma_cfg > > }, > > { .compatible = "allwinner,sun8i-h3-dma", .data = &sun8i_h3_dma_cfg }, > > + { .compatible = "allwinner,sun50i-a64-dma", .data = &sun50i_a64_dma_cfg > > }, > > { /* sentinel */ } > > }; > > MODULE_DEVICE_TABLE(of, sun6i_dma_match); > > I was wondering if should use the opportunity to expose those values as > DT properties instead of hard-wiring them to a compatible string in the > driver every time we add support for a new SoC? > We could introduce a new compatible string (say: "allwinner,sunxi-dma"), > then describe properties for the number of channels and requests and > vchans and parse those from the DT at probe time. > With this we might be able to support future SoCs without Linux *driver* > changes, by just providing the right DT. This would have worked already > for instance for the A83T support, which just changed those values. > > For instance with this quick patch below (just compile tested, and without > your refactoring). > The DT node would then read something like: > dma: dma-controller@01c02000 { > compatible = "allwinner,sun50i-a64-dma", > "allwinner,sunxi-dma"; > reg = <0x01c02000 0x1000>; > interrupts = <GIC_SPI 50 IRQ_TYPE_LEVEL_HIGH>; > clocks = <&ccu CLK_BUS_DMA>; > resets = <&ccu RST_BUS_DMA>; > #dma-cells = <1>; > allwinner,max_channels = <8>; > allwinner,max_requests = <27>; > allwinner,max_vchans = <38>; > };
We're still going to need a different compatible anyway, so it's not really like it would change anything. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
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