| Message ID | 1443115737-3948-3-git-send-email-alex.popov@linux.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Anatolij Gustschin |
| Headers | show |
Alexander Popov wrote:
> +- dma-names: should be "rx-tx";
Why bother, if it can only be one value?
On 25.09.2015 03:18, Timur Tabi wrote: > Alexander Popov wrote: >> +- dma-names: should be "rx-tx"; > > Why bother, if it can only be one value? I've just followed devicetree/bindings/dma/dma.txt... This "rx-tx" doesn't mean much but it could show that LocalPlus Bus FIFO uses a single DMA read-write channel. Should I really drop it? Best regards, Alexander
Alexander Popov wrote: > I've just followed devicetree/bindings/dma/dma.txt... > This "rx-tx" doesn't mean much but it could show that LocalPlus Bus FIFO > uses a single DMA read-write channel. Should I really drop it? Hmmm, I'm not sure. Is there anything else (besides your driver) that parses this device tree node? dma.txt says this: "The specific strings that can be used are defined in the binding of the DMA client device." So this looks like it's driver-specific, but it is a required property. I guess you should keep it, but I think you should get a second opinion.
On 28.09.2015 16:26, Timur Tabi wrote: > Alexander Popov wrote: >> I've just followed devicetree/bindings/dma/dma.txt... >> This "rx-tx" doesn't mean much but it could show that LocalPlus Bus FIFO >> uses a single DMA read-write channel. Should I really drop it? > > Hmmm, I'm not sure. Is there anything else (besides your driver) that > parses this device tree node? No, mpc512x_lpbfifo.c is the only piece of code which is going to use this device tree node. > dma.txt says this: > > "The specific strings that can be used are defined in the binding of the > DMA client device." > > So this looks like it's driver-specific, Yes. MPC512x LocalPlus Bus FIFO uses the channel #26 of the DMA controller both for reading and writing, and other DMA clients use other specific DMA channels. This channel assignment is fixed in hardware and described in the Reference Manual. > but it is a required property. > I guess you should keep it, but I think you should get a second opinion. Ok, thanks. Best regards, Alexander
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/mpc512x_lpbfifo.txt b/Documentation/devicetree/bindings/powerpc/fsl/mpc512x_lpbfifo.txt new file mode 100644 index 0000000..b3b392f --- /dev/null +++ b/Documentation/devicetree/bindings/powerpc/fsl/mpc512x_lpbfifo.txt @@ -0,0 +1,21 @@ +Freescale MPC512x LocalPlus Bus FIFO (called SCLPC in the Reference Manual) + +Required properties: +- compatible: should be "fsl,mpc512x-lpbfifo"; +- reg: should contain the offset and length of SCLPC register set; +- interrupts: should contain the interrupt specifier for SCLPC; syntax of an + interrupt client node is described in interrupt-controller/interrupts.txt; +- dmas: should contain the DMA specifier for SCLPC as described at + dma/dma.txt and dma/mpc512x-dma.txt; +- dma-names: should be "rx-tx"; + +Example: + + sclpc@10100 { + compatible = "fsl,mpc512x-lpbfifo"; + reg = <0x10100 0x50>; + interrupts = <7 0x8>; + dmas = <&dma0 26>; + dma-names = "rx-tx"; + }; + diff --git a/arch/powerpc/boot/dts/mpc5121.dtsi b/arch/powerpc/boot/dts/mpc5121.dtsi index 7f9d14f..a015e45 100644 --- a/arch/powerpc/boot/dts/mpc5121.dtsi +++ b/arch/powerpc/boot/dts/mpc5121.dtsi @@ -77,7 +77,6 @@ #address-cells = <2>; #size-cells = <1>; reg = <0x80000020 0x40>; - interrupts = <7 0x8>; ranges = <0x0 0x0 0xfc000000 0x04000000>; }; @@ -329,7 +328,15 @@ /* LocalPlus controller */ lpc@10000 { compatible = "fsl,mpc5121-lpc"; - reg = <0x10000 0x200>; + reg = <0x10000 0x100>; + }; + + sclpc@10100 { + compatible = "fsl,mpc512x-lpbfifo"; + reg = <0x10100 0x50>; + interrupts = <7 0x8>; + dmas = <&dma0 26>; + dma-names = "rx-tx"; }; pata@10200 { diff --git a/arch/powerpc/boot/dts/mpc5125twr.dts b/arch/powerpc/boot/dts/mpc5125twr.dts index e4f2974..898eb58 100644 --- a/arch/powerpc/boot/dts/mpc5125twr.dts +++ b/arch/powerpc/boot/dts/mpc5125twr.dts @@ -246,6 +246,14 @@ status = "disabled"; }; + sclpc@10100 { + compatible = "fsl,mpc512x-lpbfifo"; + reg = <0x10100 0x50>; + interrupts = <7 0x8>; + dmas = <&dma0 26>; + dma-names = "rx-tx"; + }; + // 5125 PSCs are not 52xx or 5121 PSC compatible // PSC1 uart0 aka ttyPSC0 serial@11100 { @@ -279,10 +287,11 @@ clock-names = "ipg"; }; - dma@14000 { + dma0: dma@14000 { compatible = "fsl,mpc5121-dma"; // BSP name: "mpc512x-dma2" reg = <0x14000 0x1800>; interrupts = <65 0x8>; + #dma-cells = <1>; }; }; };
Add a device tree binding for Freescale MPC512x LocalPlus Bus FIFO and introduce the document describing that binding. Signed-off-by: Alexander Popov <alex.popov@linux.com> --- .../bindings/powerpc/fsl/mpc512x_lpbfifo.txt | 21 +++++++++++++++++++++ arch/powerpc/boot/dts/mpc5121.dtsi | 11 +++++++++-- arch/powerpc/boot/dts/mpc5125twr.dts | 11 ++++++++++- 3 files changed, 40 insertions(+), 3 deletions(-) create mode 100644 Documentation/devicetree/bindings/powerpc/fsl/mpc512x_lpbfifo.txt