| Message ID | 1404825096-15724-3-git-send-email-ludovic.desroches@atmel.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Tue, Jul 08, 2014 at 03:11:36PM +0200, Ludovic Desroches wrote: > Add bindings documentation for the new Atmel DMA controller (XDMAC) > introduced with SAMA5D4. > > Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> > --- > .../devicetree/bindings/dma/atmel-xdma.txt | 48 ++++++++++++++++++++ > 1 file changed, 48 insertions(+) > create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt I dont see delta with current atmel-dma bindings. Shouldn't we reuse that here too? Surely we dont want to add binding per contoller even if they are similar!
On Fri, Jul 25, 2014 at 12:50:08PM +0530, Vinod Koul wrote: > On Tue, Jul 08, 2014 at 03:11:36PM +0200, Ludovic Desroches wrote: > > Add bindings documentation for the new Atmel DMA controller (XDMAC) > > introduced with SAMA5D4. > > > > Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> > > --- > > .../devicetree/bindings/dma/atmel-xdma.txt | 48 ++++++++++++++++++++ > > 1 file changed, 48 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt > > I dont see delta with current atmel-dma bindings. Shouldn't we reuse that > here too? Bindings have change through the revision, I didn't notice they were so close to the hdmac bindings. The only difference is the content of the second cell. I don't know if it's a sufficient reason to add a new binding. > > Surely we dont want to add binding per contoller even if they are similar! > > -- > ~Vinod > > > > > diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt > > new file mode 100644 > > index 0000000..647f099 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt > > @@ -0,0 +1,48 @@ > > +* Atmel Extensible Direct Memory Access Controller (XDMAC) > > + > > +* XDMA Controller > > +Required properties: > > +- compatible: Should be "atmel,<chip>-dma". > > +- reg: Should contain DMA registers location and length. > > +- interrupts: Should contain DMA interrupt. > > +- #dma-cells: Must be <2>, used to represent the number of integer cells in > > +the dmas property of client devices. > > + - The 1st cell specifies the memory interface (16 most significant bits) and > > + the peripheral interface (16 less significant bits) to use. > > + - The 2nd cell specifies the channel configuration register: > > + - bit 30-24: PERID, peripheral identifier. > > + > > +Example: > > + > > +dma1: dma-controller@f0004000 { > > + compatible = "atmel,sama5d4-dma"; > > + reg = <0xf0004000 0x200>; > > + interrupts = <50 4 0>; > > + #dma-cells = <2>; > > +}; > > + > > + > > +* DMA clients > > +DMA clients connected to the Atmel XDMA controller must use the format > > +described in the dma.txt file, using a two-cell specifier for each channel. > > +The three cells in order are: > > +1. A phandle pointing to the DMA controller. > > +2. The memory interface (16 most significant bits), the peripheral interface > > +(16 less significant bits). > > +3. Channel configuration register. Configurable fields are: > > + - bit 30-24: PERID, peripheral identifier. > > + > > +Example: > > + > > +i2c2: i2c@f8024000 { > > + compatible = "atmel,at91sam9x5-i2c"; > > + reg = <0xf8024000 0x4000>; > > + interrupts = <34 4 6>; > > + dmas = <&dma1 > > + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) > > + AT91_XDMAC_DT_PERID(6)>, > > + <&dma1 > > + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) > > + AT91_XDMAC_DT_PERID(7)>; > > + dma-names = "tx", "rx"; > > +}; > > -- > > 1.7.9.5 > > > > -- > -- > To unsubscribe from this list: send the line "unsubscribe dmaengine" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/devicetree/bindings/dma/atmel-xdma.txt b/Documentation/devicetree/bindings/dma/atmel-xdma.txt new file mode 100644 index 0000000..647f099 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/atmel-xdma.txt @@ -0,0 +1,48 @@ +* Atmel Extensible Direct Memory Access Controller (XDMAC) + +* XDMA Controller +Required properties: +- compatible: Should be "atmel,<chip>-dma". +- reg: Should contain DMA registers location and length. +- interrupts: Should contain DMA interrupt. +- #dma-cells: Must be <2>, used to represent the number of integer cells in +the dmas property of client devices. + - The 1st cell specifies the memory interface (16 most significant bits) and + the peripheral interface (16 less significant bits) to use. + - The 2nd cell specifies the channel configuration register: + - bit 30-24: PERID, peripheral identifier. + +Example: + +dma1: dma-controller@f0004000 { + compatible = "atmel,sama5d4-dma"; + reg = <0xf0004000 0x200>; + interrupts = <50 4 0>; + #dma-cells = <2>; +}; + + +* DMA clients +DMA clients connected to the Atmel XDMA controller must use the format +described in the dma.txt file, using a two-cell specifier for each channel. +The three cells in order are: +1. A phandle pointing to the DMA controller. +2. The memory interface (16 most significant bits), the peripheral interface +(16 less significant bits). +3. Channel configuration register. Configurable fields are: + - bit 30-24: PERID, peripheral identifier. + +Example: + +i2c2: i2c@f8024000 { + compatible = "atmel,at91sam9x5-i2c"; + reg = <0xf8024000 0x4000>; + interrupts = <34 4 6>; + dmas = <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) + AT91_XDMAC_DT_PERID(6)>, + <&dma1 + (AT91_XDMAC_DT_MEM_IF(0) | AT91_XDMAC_DT_PER_IF(1)) + AT91_XDMAC_DT_PERID(7)>; + dma-names = "tx", "rx"; +};
Add bindings documentation for the new Atmel DMA controller (XDMAC) introduced with SAMA5D4. Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> --- .../devicetree/bindings/dma/atmel-xdma.txt | 48 ++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/atmel-xdma.txt