linux/Documentation/devicetree/bindings/sound/fsl-sai.txt
Nicolin Chen ce7344a4eb ASoC: fsl_sai: Make Synchronous and Asynchronous modes exclusive
The previous patch (ASoC: fsl_sai: Add asynchronous mode support) added
new Device Tree bindings for Asynchronous and Synchronous modes support.
However, these two shall not be present at the same time.

So this patch just simply makes them exclusive so as to avoid incorrect
Device Tree binding usage.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
2014-08-16 17:06:23 -05:00

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Freescale Synchronous Audio Interface (SAI).
The SAI is based on I2S module that used communicating with audio codecs,
which provides a synchronous audio interface that supports fullduplex
serial interfaces with frame synchronization such as I2S, AC97, TDM, and
codec/DSP interfaces.
Required properties:
- compatible: Compatible list, contains "fsl,vf610-sai" or "fsl,imx6sx-sai".
- reg: Offset and length of the register set for the device.
- clocks: Must contain an entry for each entry in clock-names.
- clock-names : Must include the "bus" for register access and "mclk1" "mclk2"
"mclk3" for bit clock and frame clock providing.
- dmas : Generic dma devicetree binding as described in
Documentation/devicetree/bindings/dma/dma.txt.
- dma-names : Two dmas have to be defined, "tx" and "rx".
- pinctrl-names: Must contain a "default" entry.
- pinctrl-NNN: One property must exist for each entry in pinctrl-names.
See ../pinctrl/pinctrl-bindings.txt for details of the property values.
- big-endian-regs: If this property is absent, the little endian mode will
be in use as default, or the big endian mode will be in use for all the
device registers.
- big-endian-data: If this property is absent, the little endian mode will
be in use as default, or the big endian mode will be in use for all the
fifo data.
- fsl,sai-synchronous-rx: This is a boolean property. If present, indicating
that SAI will work in the synchronous mode (sync Tx with Rx) which means
both the transimitter and receiver will send and receive data by following
receiver's bit clocks and frame sync clocks.
- fsl,sai-asynchronous: This is a boolean property. If present, indicating
that SAI will work in the asynchronous mode, which means both transimitter
and receiver will send and receive data by following their own bit clocks
and frame sync clocks separately.
Note:
- If both fsl,sai-asynchronous and fsl,sai-synchronous-rx are absent, the
default synchronous mode (sync Rx with Tx) will be used, which means both
transimitter and receiver will send and receive data by following clocks
of transimitter.
- fsl,sai-asynchronous and fsl,sai-synchronous-rx are exclusive.
Example:
sai2: sai@40031000 {
compatible = "fsl,vf610-sai";
reg = <0x40031000 0x1000>;
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_sai2_1>;
clocks = <&clks VF610_CLK_PLATFORM_BUS>,
<&clks VF610_CLK_SAI2>,
<&clks 0>, <&clks 0>;
clock-names = "bus", "mclk1", "mclk2", "mclk3";
dma-names = "tx", "rx";
dmas = <&edma0 0 VF610_EDMA_MUXID0_SAI2_TX>,
<&edma0 0 VF610_EDMA_MUXID0_SAI2_RX>;
big-endian-regs;
big-endian-data;
};