| Message ID | 1445003956-9150-2-git-send-email-cedric.madianga@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 16, 2015 at 8:59 AM, M'boumba Cedric Madianga <cedric.madianga@gmail.com> wrote: > This patch adds documentation of device tree bindings for the STM32 dma > controller. > > Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com> > --- > .../devicetree/bindings/dma/stm32-dma.txt | 82 ++++++++++++++++++++++ Acked-by: Rob Herring <robh@kernel.org> > 1 file changed, 82 insertions(+) > create mode 100644 Documentation/devicetree/bindings/dma/stm32-dma.txt > > diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt > new file mode 100644 > index 0000000..70cd13f > --- /dev/null > +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt > @@ -0,0 +1,82 @@ > +* STMicroelectronics STM32 DMA controller > + > +The STM32 DMA is a general-purpose direct memory access controller capable of > +supporting 8 independent DMA channels. Each channel can have up to 8 requests. > + > +Required properties: > +- compatible: Should be "st,stm32-dma" > +- reg: Should contain DMA registers location and length. This should include > + all of the per-channel registers. > +- interrupts: Should contain all of the per-channel DMA interrupts in > + ascending order with respect to the DMA channel index. > +- clocks: Should contain the input clock of the DMA instance. > +- #dma-cells : Must be <4>. See DMA client paragraph for more details. > + > +Optional properties: > +- resets: Reference to a reset controller asserting the DMA controller > +- st,mem2mem: boolean; if defined, it indicates that the controller supports > + memory-to-memory transfer > + > +Example: > + > + dma2: dma-controller@40026400 { > + compatible = "st,stm32-dma"; > + reg = <0x40026400 0x400>; > + interrupts = <56>, > + <57>, > + <58>, > + <59>, > + <60>, > + <68>, > + <69>, > + <70>; > + clocks = <&clk_hclk>; > + #dma-cells = <4>; > + st,mem2mem; > + resets = <&rcc 150>; > + }; > + > +* DMA client > + > +DMA clients connected to the STM32 DMA controller must use the format > +described in the dma.txt file, using a five-cell specifier for each > +channel: a phandle plus four integer cells. > +The four cells in order are: > + > +1. The channel id > +2. The request line number > +3. A 32bit mask specifying the DMA channel configuration which are device > + dependent: > + -bit 9: Peripheral Increment Address > + 0x0: no address increment between transfers > + 0x1: increment address between transfers > + -bit 10: Memory Increment Address > + 0x0: no address increment between transfers > + 0x1: increment address between transfers > + -bit 15: Peripheral Increment Offset Size > + 0x0: offset size is linked to the peripheral bus width > + 0x1: offset size is fixed to 4 (32-bit alignment) > + -bit 16-17: Priority level > + 0x0: low > + 0x1: medium > + 0x2: high > + 0x3: very high > +5. A 32bit mask specifying the DMA FIFO threshold configuration which are device > + dependent: > + -bit 0-1: Fifo threshold > + 0x0: 1/4 full FIFO > + 0x1: 1/2 full FIFO > + 0x2: 3/4 full FIFO > + 0x3: full FIFO > + > +Example: > + > + usart1: serial@40011000 { > + compatible = "st,stm32-usart", "st,stm32-uart"; > + reg = <0x40011000 0x400>; > + interrupts = <37>; > + clocks = <&clk_pclk2>; > + dmas = <&dma2 2 4 0x10400 0x3>, > + <&dma2 7 5 0x10200 0x3>; > + dma-names = "rx", "tx"; > + }; > -- > 1.9.1 >
On Fri, Oct 16, 2015 at 03:59:13PM +0200, M'boumba Cedric Madianga wrote: > This patch adds documentation of device tree bindings for the STM32 dma > controller. > Applied, thanks
diff --git a/Documentation/devicetree/bindings/dma/stm32-dma.txt b/Documentation/devicetree/bindings/dma/stm32-dma.txt new file mode 100644 index 0000000..70cd13f --- /dev/null +++ b/Documentation/devicetree/bindings/dma/stm32-dma.txt @@ -0,0 +1,82 @@ +* STMicroelectronics STM32 DMA controller + +The STM32 DMA is a general-purpose direct memory access controller capable of +supporting 8 independent DMA channels. Each channel can have up to 8 requests. + +Required properties: +- compatible: Should be "st,stm32-dma" +- reg: Should contain DMA registers location and length. This should include + all of the per-channel registers. +- interrupts: Should contain all of the per-channel DMA interrupts in + ascending order with respect to the DMA channel index. +- clocks: Should contain the input clock of the DMA instance. +- #dma-cells : Must be <4>. See DMA client paragraph for more details. + +Optional properties: +- resets: Reference to a reset controller asserting the DMA controller +- st,mem2mem: boolean; if defined, it indicates that the controller supports + memory-to-memory transfer + +Example: + + dma2: dma-controller@40026400 { + compatible = "st,stm32-dma"; + reg = <0x40026400 0x400>; + interrupts = <56>, + <57>, + <58>, + <59>, + <60>, + <68>, + <69>, + <70>; + clocks = <&clk_hclk>; + #dma-cells = <4>; + st,mem2mem; + resets = <&rcc 150>; + }; + +* DMA client + +DMA clients connected to the STM32 DMA controller must use the format +described in the dma.txt file, using a five-cell specifier for each +channel: a phandle plus four integer cells. +The four cells in order are: + +1. The channel id +2. The request line number +3. A 32bit mask specifying the DMA channel configuration which are device + dependent: + -bit 9: Peripheral Increment Address + 0x0: no address increment between transfers + 0x1: increment address between transfers + -bit 10: Memory Increment Address + 0x0: no address increment between transfers + 0x1: increment address between transfers + -bit 15: Peripheral Increment Offset Size + 0x0: offset size is linked to the peripheral bus width + 0x1: offset size is fixed to 4 (32-bit alignment) + -bit 16-17: Priority level + 0x0: low + 0x1: medium + 0x2: high + 0x3: very high +5. A 32bit mask specifying the DMA FIFO threshold configuration which are device + dependent: + -bit 0-1: Fifo threshold + 0x0: 1/4 full FIFO + 0x1: 1/2 full FIFO + 0x2: 3/4 full FIFO + 0x3: full FIFO + +Example: + + usart1: serial@40011000 { + compatible = "st,stm32-usart", "st,stm32-uart"; + reg = <0x40011000 0x400>; + interrupts = <37>; + clocks = <&clk_pclk2>; + dmas = <&dma2 2 4 0x10400 0x3>, + <&dma2 7 5 0x10200 0x3>; + dma-names = "rx", "tx"; + };
This patch adds documentation of device tree bindings for the STM32 dma controller. Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com> --- .../devicetree/bindings/dma/stm32-dma.txt | 82 ++++++++++++++++++++++ 1 file changed, 82 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/stm32-dma.txt