From: Laurent Pinchart Date: Thu, 31 Jul 2014 00:34:07 +0000 (+0900) Subject: dmaengine: rcar-dmac: Add device tree bindings documentation X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=10f5c8438475909a27b5fb1c3270d58ae5178ce2;p=linux-beck.git dmaengine: rcar-dmac: Add device tree bindings documentation Document the device tree bindings for the R-Car Generation 2 DMA Controller (DMAC). Cc: devicetree@vger.kernel.org Signed-off-by: Laurent Pinchart Signed-off-by: Simon Horman Signed-off-by: Vinod Koul --- diff --git a/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt new file mode 100644 index 000000000000..df0f48bcf75a --- /dev/null +++ b/Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt @@ -0,0 +1,98 @@ +* Renesas R-Car DMA Controller Device Tree bindings + +Renesas R-Car Generation 2 SoCs have have multiple multi-channel DMA +controller instances named DMAC capable of serving multiple clients. Channels +can be dedicated to specific clients or shared between a large number of +clients. + +DMA clients are connected to the DMAC ports referenced by an 8-bit identifier +called MID/RID. + +Each DMA client is connected to one dedicated port of the DMAC, identified by +an 8-bit port number called the MID/RID. A DMA controller can thus serve up to +256 clients in total. When the number of hardware channels is lower than the +number of clients to be served, channels must be shared between multiple DMA +clients. The association of DMA clients to DMAC channels is fully dynamic and +not described in these device tree bindings. + +Required Properties: + +- compatible: must contain "renesas,rcar-dmac" + +- reg: base address and length of the registers block for the DMAC + +- interrupts: interrupt specifiers for the DMAC, one for each entry in + interrupt-names. +- interrupt-names: one entry per channel, named "ch%u", where %u is the + channel number ranging from zero to the number of channels minus one. + +- clock-names: "fck" for the functional clock +- clocks: a list of phandle + clock-specifier pairs, one for each entry + in clock-names. +- clock-names: must contain "fck" for the functional clock. + +- #dma-cells: must be <1>, the cell specifies the MID/RID of the DMAC port + connected to the DMA client +- dma-channels: number of DMA channels + +Example: R8A7790 (R-Car H2) SYS-DMACs + + dmac0: dma-controller@e6700000 { + compatible = "renesas,rcar-dmac"; + reg = <0 0xe6700000 0 0x20000>; + interrupts = <0 197 IRQ_TYPE_LEVEL_HIGH + 0 200 IRQ_TYPE_LEVEL_HIGH + 0 201 IRQ_TYPE_LEVEL_HIGH + 0 202 IRQ_TYPE_LEVEL_HIGH + 0 203 IRQ_TYPE_LEVEL_HIGH + 0 204 IRQ_TYPE_LEVEL_HIGH + 0 205 IRQ_TYPE_LEVEL_HIGH + 0 206 IRQ_TYPE_LEVEL_HIGH + 0 207 IRQ_TYPE_LEVEL_HIGH + 0 208 IRQ_TYPE_LEVEL_HIGH + 0 209 IRQ_TYPE_LEVEL_HIGH + 0 210 IRQ_TYPE_LEVEL_HIGH + 0 211 IRQ_TYPE_LEVEL_HIGH + 0 212 IRQ_TYPE_LEVEL_HIGH + 0 213 IRQ_TYPE_LEVEL_HIGH + 0 214 IRQ_TYPE_LEVEL_HIGH>; + interrupt-names = "error", + "ch0", "ch1", "ch2", "ch3", + "ch4", "ch5", "ch6", "ch7", + "ch8", "ch9", "ch10", "ch11", + "ch12", "ch13", "ch14"; + clocks = <&mstp2_clks R8A7790_CLK_SYS_DMAC0>; + clock-names = "fck"; + #dma-cells = <1>; + dma-channels = <15>; + }; + + dmac1: dma-controller@e6720000 { + compatible = "renesas,rcar-dmac"; + reg = <0 0xe6720000 0 0x20000>; + interrupts = <0 220 IRQ_TYPE_LEVEL_HIGH + 0 216 IRQ_TYPE_LEVEL_HIGH + 0 217 IRQ_TYPE_LEVEL_HIGH + 0 218 IRQ_TYPE_LEVEL_HIGH + 0 219 IRQ_TYPE_LEVEL_HIGH + 0 308 IRQ_TYPE_LEVEL_HIGH + 0 309 IRQ_TYPE_LEVEL_HIGH + 0 310 IRQ_TYPE_LEVEL_HIGH + 0 311 IRQ_TYPE_LEVEL_HIGH + 0 312 IRQ_TYPE_LEVEL_HIGH + 0 313 IRQ_TYPE_LEVEL_HIGH + 0 314 IRQ_TYPE_LEVEL_HIGH + 0 315 IRQ_TYPE_LEVEL_HIGH + 0 316 IRQ_TYPE_LEVEL_HIGH + 0 317 IRQ_TYPE_LEVEL_HIGH + 0 318 IRQ_TYPE_LEVEL_HIGH>; + interrupt-names = "error", + "ch0", "ch1", "ch2", "ch3", + "ch4", "ch5", "ch6", "ch7", + "ch8", "ch9", "ch10", "ch11", + "ch12", "ch13", "ch14"; + clocks = <&mstp2_clks R8A7790_CLK_SYS_DMAC1>; + clock-names = "fck"; + #dma-cells = <1>; + dma-channels = <15>; + };