Messages in this thread | | | Date | Mon, 08 Apr 2013 12:46:47 +0200 | From | Lars-Peter Clausen <> | Subject | Re: [PATCH 1/2] dmaengine: mpc512x_dma: use generic DMA DT bindings |
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On 03/31/2013 06:17 PM, Anatolij Gustschin wrote: > Add generic DMA bindings and register the DMA controller > to DT DMA helpers. > > Signed-off-by: Anatolij Gustschin <agust@denx.de> > --- > arch/powerpc/boot/dts/mpc5121.dtsi | 5 ++- > drivers/dma/mpc512x_dma.c | 63 ++++++++++++++++++++++++++++++++++-- > 2 files changed, 64 insertions(+), 4 deletions(-) > > diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi > index 723e292..d1fe070 100644 > --- a/arch/powerpc/boot/dts/mpc5121.dtsi > +++ b/arch/powerpc/boot/dts/mpc5121.dtsi > @@ -384,10 +384,13 @@ > interrupts = <40 0x8>; > }; > > - dma@14000 { > + dma0: dma@14000 { > compatible = "fsl,mpc5121-dma"; > reg = <0x14000 0x1800>; > interrupts = <65 0x8>; > + #dma-cells = <1>; > + #dma-channels = <64>; > + #dma-requests = <64>; > }; > }; > > diff --git a/drivers/dma/mpc512x_dma.c b/drivers/dma/mpc512x_dma.c > index 2d95673..bc6c356 100644 > --- a/drivers/dma/mpc512x_dma.c > +++ b/drivers/dma/mpc512x_dma.c > @@ -40,6 +40,7 @@ > #include <linux/io.h> > #include <linux/slab.h> > #include <linux/of_device.h> > +#include <linux/of_dma.h> > #include <linux/of_platform.h> > > #include <linux/random.h> > @@ -641,6 +642,44 @@ mpc_dma_prep_memcpy(struct dma_chan *chan, dma_addr_t dst, dma_addr_t src, > return &mdesc->desc; > } > > +struct mpc_dma_filter_args { > + struct mpc_dma *mdma; > + unsigned int chan_id; > +}; > + > +static bool mpc_dma_filter(struct dma_chan *chan, void *param) > +{ > + struct mpc_dma_filter_args *fargs = param; > + > + if (chan->device != &fargs->mdma->dma) > + return false; > + > + return (chan->chan_id == fargs->chan_id); > +} > + > +static struct dma_chan *mpc_dma_xlate(struct of_phandle_args *dma_spec, > + struct of_dma *ofdma) > +{ > + int count = dma_spec->args_count; > + struct mpc_dma *mdma = ofdma->of_dma_data; > + struct mpc_dma_filter_args fargs; > + dma_cap_mask_t cap; > + > + if (!mdma) > + return NULL; > + > + if (count != 1) > + return NULL; > + > + fargs.mdma = mdma; > + fargs.chan_id = dma_spec->args[0]; > + > + dma_cap_zero(cap); > + dma_cap_set(DMA_SLAVE, cap); > + > + return dma_request_channel(cap, mpc_dma_filter, &fargs); > +} > +
This is more or less the same as the generic of_dma_xlate_by_chan_id function I posted about two weeks ago: https://patchwork.kernel.org/patch/2331091/
Vinod, can you take a look at that patch again? I'm not quite sure what you meant by your question 'how will the client know which "id" to request?'.
- Lars
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