查看“SPDIFRX Linux driver”的源代码

== Article purpose ==
本文介绍了适用于[[SPDIFRX internal peripheral]]的SPDIFRX  Linux<sup>&reg;</sup>驱动程序。

== Short Description ==
SPDIFRX<ref name="SPDIFRX internal peripheral">[[SPDIFRX internal peripheral]]</ref> Linux 驱动程序是在Linux[[ALSA_overview|ALSA framework]]中实现的ASoC CPU DAI驱动程序。

== Configuration ==

=== Kernel Configuration ===
使用Linux Menuconfig工具在内核配置中激活SPDIFRX<ref name="SPDIFRX internal peripheral"/>  Linux驱动程序： [[Menuconfig or how to configure kernel]]
<pre>
[*] Device Drivers
    [*] Sound card support
        [*] Advanced Linux Sound Architecture
            [*] ALSA for SoC audio support
                STMicroelectronics STM32 SOC audio support
	             [*] STM32 S/PDIF receiver (SPDIFRX) support
</pre>

=== Device tree ===
配置SPDIFRX Linux内核驱动程序时，请参考[[SPDIFRX device tree configuration]] 。

== How to use ==
可通过ALSA设备从用户区访问SPDIFRX驱动程序。 请参阅[[ALSA_overview#How_to_use|ALSA overview]] ，以了解如何列出和使用ALSA设备。


SPDFIRX驱动程序公开了一个alsa控件，该控件允许从输入音频流中检索IEC958状态位。

{{Warning|设备树中SPDIFRX输入引脚的配置可能会对IEC958控制的使用施加一些限制。因此，在某些配置中，仅当捕获音频流时才能使用控件。有关SPDIFRX配置的详细信息，请参阅[[SPDIFRX device tree configuration]]。}}

== How to debug ==
The [[Debugfs|debugfs]] and procfs file systems can be checked to get information about the SPDFIRX driver and the resources it uses. A none exhaustive list of these file system entries is provided below. Refer to [[ALSA_overview#How_to_trace_and_debug_the_framework|ALSA overview]] to get more details about debugging tools.

* debugfs entries:
:* '''asoc''': refer to [[ALSA_overview#How_to_monitor]]
:* '''clk''': refer to [[Clock_overview#How_to_monitor_with_debugfs]] to get information on clocks.
:* '''pinctrl''': refer to [[Pinctrl_overview#How_to_monitor]] to get information on pins.
:* '''regmap''': allow to monitor SPDIFRX peripheral registers.
<div style="margin-left: 2em;">
 $ cat /sys/kernel/debug/regmap/xxx.audio-controller/registers
</div>
* procfs entries:
:* '''asound''': refer to [[ALSA_overview#How_to_debug]]
:* '''interrupts''': allow to check interrupts.
<div style="margin-left: 2em;">
 $ cat /proc/interrupts
</div>

== Source code location ==
{{CodeSource | Linux kernel | sound/soc/stm/stm32_spdifrx.c}}: implements the SPDIFRX driver.

==References==
<references />