[PATCH v2 1/9] dmaengine: st_fdma: Add STMicroelectronics FDMA DT binding documentation
From: Peter Griffin
Date: Fri Sep 11 2015 - 10:17:44 EST
This patch adds the DT binding documentation for the FDMA constroller
found on STi based chipsets from STMicroelectronics.
Signed-off-by: Ludovic Barre <ludovic.barre@xxxxxx>
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
---
Documentation/devicetree/bindings/dma/st_fdma.txt | 78 +++++++++++++++++++++++
1 file changed, 78 insertions(+)
create mode 100644 Documentation/devicetree/bindings/dma/st_fdma.txt
diff --git a/Documentation/devicetree/bindings/dma/st_fdma.txt b/Documentation/devicetree/bindings/dma/st_fdma.txt
new file mode 100644
index 0000000..c24b8d7
--- /dev/null
+++ b/Documentation/devicetree/bindings/dma/st_fdma.txt
@@ -0,0 +1,78 @@
+* STMicroelectronics Flexible Direct Memory Access Device Tree bindings
+
+The FDMA is a general-purpose direct memory access controller capable of
+supporting 16 independent DMA channels. It accepts up to 32 DMA requests.
+The FDMA is based on a Slim processor which require a firmware.
+
+* FDMA Controller
+
+Required properties:
+- compatible : Should be "st,stih407-fdma-mpe31"
+- reg : Should contain DMA registers location and length
+- interrupts : Should contain one interrupt shared by all channels
+- dma-channels : Number of channels supported by the controller
+- #dma-cells : Must be <3>. See DMA client section below
+- st,fdma-id : Must contain fdma controller number
+- clocks : Must contain an entry for each name in clock-names
+- clock-names : Must contain "fdma_slim, fdma_hi, fdma_low, fdma_ic" entries
+See: Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+
+Example:
+
+ fdma1: fdma-app@8e40000 {
+ compatible = "st,stih407-fdma-mpe31";
+ reg = <0x8e40000 0x20000>;
+ interrupts = <GIC_SPI 7 IRQ_TYPE_NONE>;
+ dma-channels = <16>;
+ #dma-cells = <3>;
+ st,fdma-id = <0>;
+ clocks = <&CLK_S_C0_FLEXGEN CLK_FDMA>,
+ <&CLK_S_C0_FLEXGEN CLK_TX_ICN_DMU>,
+ <&CLK_S_C0_FLEXGEN CLK_TX_ICN_DMU>,
+ <&CLK_S_C0_FLEXGEN CLK_EXT2F_A9>;
+ clock-names = "fdma_slim",
+ "fdma_hi",
+ "fdma_low",
+ "fdma_ic";
+ };
+
+* DMA client
+
+Required properties:
+- dmas: Comma separated list of dma channel requests
+- dma-names: Names of the aforementioned requested channels
+
+Each dmas request consists of 4 cells:
+1. A phandle pointing to the FDMA controller
+2. The request line number
+3. A 32bit mask specifying (see include/linux/platform_data/dma-st-fdma.h)
+ -bit 2-0: Holdoff value, dreq will be masked for
+ 0x0: 0-0.5us
+ 0x1: 0.5-1us
+ 0x2: 1-1.5us
+ -bit 17: data swap
+ 0x0: disabled
+ 0x1: enabled
+ -bit 21: Increment Address
+ 0x0: no address increment between transfers
+ 0x1: increment address between transfers
+ -bit 22: 2 STBus Initiator Coprocessor interface
+ 0x0: high priority port
+ 0x1: low priority port
+4. transfers type
+ 0 free running
+ 1 paced
+
+Example:
+
+ snd_uni_player2: snd-uni-player@2 {
+ compatible = "st,snd_uni_player";
+ status = "okay";
+ reg = <0x8D82000 0x158>;
+ interrupts = <GIC_SPI 86 IRQ_TYPE_NONE>;
+ version = <5>;
+ dmas = <&fdma0 4 0 1>;
+ dma-names = "tx";
+ description = "Uni Player #2 (DAC)";
+ };
--
1.9.1
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