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-rw-r--r--Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt28
1 files changed, 28 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
index dc8d3aac1aa9..3c9a57a8443b 100644
--- a/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
+++ b/Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
@@ -8,6 +8,7 @@ Required properties:
"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.
@@ -58,6 +59,15 @@ The third cell specifies the transfer priority as below.
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 {
@@ -83,3 +93,21 @@ ssi2: ssi@70014000 {
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.