linux/Documentation/devicetree/bindings/sound/fsl,esai.txt
Shengjiu Wang a2a4d6049a ASoC: fsl_esai: spba clock is needed by esai device
ESAI need to enable the spba clock, when sdma is using share peripheral
script. In this case, there is two spba master port is used, if don't
enable the clock, the spba bus will have arbitration issue, which may
cause read/write wrong data from/to ESAI registers.

Signed-off-by: Shengjiu Wang <shengjiu.wang@freescale.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2015-11-25 12:13:46 +00:00

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Freescale Enhanced Serial Audio Interface (ESAI) Controller
The Enhanced Serial Audio Interface (ESAI) provides a full-duplex serial port
for serial communication with a variety of serial devices, including industry
standard codecs, Sony/Phillips Digital Interface (S/PDIF) transceivers, and
other DSPs. It has up to six transmitters and four receivers.
Required properties:
- compatible : Compatible list, must contain "fsl,imx35-esai" or
"fsl,vf610-esai"
- reg : Offset and length of the register set for the device.
- interrupts : Contains the spdif interrupt.
- 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".
- clocks : Contains an entry for each entry in clock-names.
- clock-names : Includes the following entries:
"core" The core clock used to access registers
"extal" The esai baud clock for esai controller used to
derive HCK, SCK and FS.
"fsys" The system clock derived from ahb clock used to
derive HCK, SCK and FS.
"spba" The spba clock is required when ESAI is placed as a
bus slave of the Shared Peripheral Bus and when two
or more bus masters (CPU, DMA or DSP) try to access
it. This property is optional depending on the SoC
design.
- fsl,fifo-depth : The number of elements in the transmit and receive
FIFOs. This number is the maximum allowed value for
TFCR[TFWM] or RFCR[RFWM].
- fsl,esai-synchronous: This is a boolean property. If present, indicating
that ESAI would work in the synchronous mode, which
means all the settings for Receiving would be
duplicated from Transmition related registers.
- big-endian : If this property is absent, the native endian mode
will be in use as default, or the big endian mode
will be in use for all the device registers.
Example:
esai: esai@02024000 {
compatible = "fsl,imx35-esai";
reg = <0x02024000 0x4000>;
interrupts = <0 51 0x04>;
clocks = <&clks 208>, <&clks 118>, <&clks 208>;
clock-names = "core", "extal", "fsys";
dmas = <&sdma 23 21 0>, <&sdma 24 21 0>;
dma-names = "rx", "tx";
fsl,fifo-depth = <128>;
fsl,esai-synchronous;
big-endian;
status = "disabled";
};