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Diffstat (limited to 'Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt')
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diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt new file mode 100644 index 000000000..3c9a57a84 --- /dev/null +++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt @@ -0,0 +1,113 @@ +* Freescale Smart Direct Memory Access (SDMA) Controller for i.MX + +Required properties: +- compatible : Should be one of + "fsl,imx25-sdma" + "fsl,imx31-sdma", "fsl,imx31-to1-sdma", "fsl,imx31-to2-sdma" + "fsl,imx35-sdma", "fsl,imx35-to1-sdma", "fsl,imx35-to2-sdma" + "fsl,imx51-sdma" + "fsl,imx53-sdma" + "fsl,imx6q-sdma" + "fsl,imx7d-sdma" + The -to variants should be preferred since they allow to determine the + correct ROM script addresses needed for the driver to work without additional + firmware. +- reg : Should contain SDMA registers location and length +- interrupts : Should contain SDMA interrupt +- #dma-cells : Must be <3>. + The first cell specifies the DMA request/event ID. See details below + about the second and third cell. +- fsl,sdma-ram-script-name : Should contain the full path of SDMA RAM + scripts firmware + +The second cell of dma phandle specifies the peripheral type of DMA transfer. +The full ID of peripheral types can be found below. + + ID transfer type + --------------------- + 0 MCU domain SSI + 1 Shared SSI + 2 MMC + 3 SDHC + 4 MCU domain UART + 5 Shared UART + 6 FIRI + 7 MCU domain CSPI + 8 Shared CSPI + 9 SIM + 10 ATA + 11 CCM + 12 External peripheral + 13 Memory Stick Host Controller + 14 Shared Memory Stick Host Controller + 15 DSP + 16 Memory + 17 FIFO type Memory + 18 SPDIF + 19 IPU Memory + 20 ASRC + 21 ESAI + 22 SSI Dual FIFO (needs firmware ver >= 2) + 23 Shared ASRC + 24 SAI + +The third cell specifies the transfer priority as below. + + ID transfer priority + ------------------------- + 0 High + 1 Medium + 2 Low + +Optional properties: + +- gpr : The phandle to the General Purpose Register (GPR) node. +- fsl,sdma-event-remap : Register bits of sdma event remap, the format is + <reg shift val>. + reg is the GPR register offset. + shift is the bit position inside the GPR register. + val is the value of the bit (0 or 1). + +Examples: + +sdma@83fb0000 { + compatible = "fsl,imx51-sdma", "fsl,imx35-sdma"; + reg = <0x83fb0000 0x4000>; + interrupts = <6>; + #dma-cells = <3>; + fsl,sdma-ram-script-name = "sdma-imx51.bin"; +}; + +DMA clients connected to the i.MX SDMA controller must use the format +described in the dma.txt file. + +Examples: + +ssi2: ssi@70014000 { + compatible = "fsl,imx51-ssi", "fsl,imx21-ssi"; + reg = <0x70014000 0x4000>; + interrupts = <30>; + clocks = <&clks 49>; + dmas = <&sdma 24 1 0>, + <&sdma 25 1 0>; + dma-names = "rx", "tx"; + fsl,fifo-depth = <15>; +}; + +Using the fsl,sdma-event-remap property: + +If we want to use SDMA on the SAI1 port on a MX6SX: + +&sdma { + gpr = <&gpr>; + /* SDMA events remap for SAI1_RX and SAI1_TX */ + fsl,sdma-event-remap = <0 15 1>, <0 16 1>; +}; + +The fsl,sdma-event-remap property in this case has two values: +- <0 15 1> means that the offset is 0, so GPR0 is the register of the +SDMA remap. Bit 15 of GPR0 selects between UART4_RX and SAI1_RX. +Setting bit 15 to 1 selects SAI1_RX. +- <0 16 1> means that the offset is 0, so GPR0 is the register of the +SDMA remap. Bit 16 of GPR0 selects between UART4_TX and SAI1_TX. +Setting bit 16 to 1 selects SAI1_TX. |