OpenCloudOS-Kernel/Documentation/devicetree/bindings/sound/fsl-sai.txt

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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",
"fsl,imx6sx-sai", "fsl,imx6ul-sai",
"fsl,imx7ulp-sai", "fsl,imx8mq-sai",
"fsl,imx8qm-sai", "fsl,imx8mm-sai",
"fsl,imx8mn-sai", "fsl,imx8mp-sai", or
"fsl,imx8ulp-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.
"pll8k", "pll11k" are optional, they are the clock
source for root clock, one is for 8kHz series rates
another one is for 11kHz series rates.
- 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.
- lsb-first : Configures whether the LSB or the MSB is transmitted
first for the fifo data. If this property is absent,
the MSB is transmitted first as default, or the LSB
is transmitted first.
- 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 transmitter and the
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 transmitter and receiver will send and
receive data by following their own bit clocks and
frame sync clocks separately.
- fsl,dataline : configure the dataline. it has 3 value for each configuration
first one means the type: I2S(1) or PDM(2)
second one is dataline mask for 'rx'
third one is dataline mask for 'tx'.
for example: fsl,dataline = <1 0xff 0xff 2 0xff 0x11>;
it means I2S type rx mask is 0xff, tx mask is 0xff, PDM type
rx mask is 0xff, tx mask is 0x11 (dataline 1 and 4 enabled).
Optional properties:
- big-endian : Boolean property, required if all the SAI
registers are big-endian rather than little-endian.
Optional properties (for mx6ul):
- fsl,sai-mclk-direction-output: This is a boolean property. If present,
indicates that SAI will output the SAI MCLK clock.
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
transmitter and receiver will send and receive data by following clocks
of transmitter.
- 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;
lsb-first;
};