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The 'big-endian-data' property is originally used to indicate whether the LSB firstly or MSB firstly will be transmitted to the CODEC or received from the CODEC, and there has nothing relation to the memory data. Generally, if the audio data in big endian format, which will be using the bytes reversion, Here this can only be used to bits reversion. So using the 'lsb-first' instead of 'big-endian-data' can make the code to be readable easier and more easy to understand what this property is used to do. This property used for configuring whether the LSB or the MSB is transmitted first for the fifo data. Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com> Acked-by: Nicolin Chen <nicoleotsuka@gmail.com> Signed-off-by: Mark Brown <broonie@kernel.org>
58 lines
2.6 KiB
Plaintext
58 lines
2.6 KiB
Plaintext
Freescale Synchronous Audio Interface (SAI).
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The SAI is based on I2S module that used communicating with audio codecs,
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which provides a synchronous audio interface that supports fullduplex
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serial interfaces with frame synchronization such as I2S, AC97, TDM, and
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codec/DSP interfaces.
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Required properties:
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- compatible: Compatible list, contains "fsl,vf610-sai" or "fsl,imx6sx-sai".
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- reg: Offset and length of the register set for the device.
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- clocks: Must contain an entry for each entry in clock-names.
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- clock-names : Must include the "bus" for register access and "mclk1" "mclk2"
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"mclk3" for bit clock and frame clock providing.
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- dmas : Generic dma devicetree binding as described in
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Documentation/devicetree/bindings/dma/dma.txt.
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- dma-names : Two dmas have to be defined, "tx" and "rx".
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- pinctrl-names: Must contain a "default" entry.
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- pinctrl-NNN: One property must exist for each entry in pinctrl-names.
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See ../pinctrl/pinctrl-bindings.txt for details of the property values.
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- big-endian: Boolean property, required if all the FTM_PWM registers
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are big-endian rather than little-endian.
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- lsb-first: Configures whether the LSB or the MSB is transmitted first for
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the fifo data. If this property is absent, the MSB is transmitted first as
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default, or the LSB is transmitted first.
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- fsl,sai-synchronous-rx: This is a boolean property. If present, indicating
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that SAI will work in the synchronous mode (sync Tx with Rx) which means
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both the transimitter and receiver will send and receive data by following
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receiver's bit clocks and frame sync clocks.
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- fsl,sai-asynchronous: This is a boolean property. If present, indicating
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that SAI will work in the asynchronous mode, which means both transimitter
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and receiver will send and receive data by following their own bit clocks
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and frame sync clocks separately.
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Note:
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- If both fsl,sai-asynchronous and fsl,sai-synchronous-rx are absent, the
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default synchronous mode (sync Rx with Tx) will be used, which means both
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transimitter and receiver will send and receive data by following clocks
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of transimitter.
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- fsl,sai-asynchronous and fsl,sai-synchronous-rx are exclusive.
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Example:
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sai2: sai@40031000 {
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compatible = "fsl,vf610-sai";
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reg = <0x40031000 0x1000>;
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pinctrl-names = "default";
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pinctrl-0 = <&pinctrl_sai2_1>;
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clocks = <&clks VF610_CLK_PLATFORM_BUS>,
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<&clks VF610_CLK_SAI2>,
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<&clks 0>, <&clks 0>;
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clock-names = "bus", "mclk1", "mclk2", "mclk3";
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dma-names = "tx", "rx";
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dmas = <&edma0 0 VF610_EDMA_MUXID0_SAI2_TX>,
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<&edma0 0 VF610_EDMA_MUXID0_SAI2_RX>;
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big-endian;
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lsb-first;
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};
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