“SPDIFRX Linux driver”的版本间的差异

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{{DISPLAYTITLE:SPDIFRX Linux驱动程序}}
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== Article purpose ==
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This article introduces the SPDIFRX Linux<sup>&reg;</sup> driver for the [[SPDIFRX internal peripheral]].
  
[[Category:Linux_Operating_System]]
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== Short Description ==
[[Category:Audio]]
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The SPDIFRX<ref name="SPDIFRX internal peripheral">[[SPDIFRX internal peripheral]]</ref> Linux driver is an ASoC CPU DAI driver implemented in the Linux [[ALSA_overview|ALSA framework]].
[[Category:ALSA]]
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== Configuration ==
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=== Kernel Configuration ===
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Activate the SPDIFRX<ref name="SPDIFRX internal peripheral"/> Linux driver in the kernel configuration using the Linux Menuconfig tool: [[Menuconfig or how to configure kernel]]
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<pre>
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[*] Device Drivers
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    [*] Sound card support
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        [*] Advanced Linux Sound Architecture
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            [*] ALSA for SoC audio support
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                STMicroelectronics STM32 SOC audio support
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            [*] STM32 S/PDIF receiver (SPDIFRX) support
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</pre>
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=== Device tree ===
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Refer to the [[SPDIFRX device tree configuration]] article when configuring the SPDIFRX Linux kernel driver.
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== How to use ==
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The SPDIFRX driver is accessed from userland through an ALSA device. Refer to [[ALSA_overview#How_to_use|ALSA overview]] to see how to list and use ALSA devices.
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The SPDFIRX driver exposes an alsa control, which allows to retrieve the IEC958 status bits from
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the input audio stream.
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{{Warning|The configuration of the SPDIFRX input pin in the device tree, may put some restrictions on the use of IEC958 control. Thus, in some configuration, the control can be used only when an audio stream is captured. Refer to the [[SPDIFRX device tree configuration]] article, to find details about SPDIFRX configuration.}}
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== How to debug ==
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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.
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* debugfs entries:
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:* '''asoc''': refer to [[ALSA_overview#How_to_monitor]]
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:* '''clk''': refer to [[Clock_overview#How_to_monitor_with_debugfs]] to get information on clocks.
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:* '''pinctrl''': refer to [[Pinctrl_overview#How_to_monitor]] to get information on pins.
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:* '''regmap''': allow to monitor SPDIFRX peripheral registers.
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<div style="margin-left: 2em;">
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$ cat /sys/kernel/debug/regmap/xxx.audio-controller/registers
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</div>
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* procfs entries:
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:* '''asound''': refer to [[ALSA_overview#How_to_debug]]
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:* '''interrupts''': allow to check interrupts.
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<div style="margin-left: 2em;">
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$ cat /proc/interrupts
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</div>
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== Source code location ==
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{{CodeSource | Linux kernel | sound/soc/stm/stm32_spdifrx.c}}: implements the SPDIFRX driver.
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==References==
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<references />
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<noinclude>
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{{ArticleBasedOnModel | Peripheral or framework device tree configuration model}}
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{{PublicationRequestId | 9234 | 2018-10-22 | BrunoB}
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[[Category:ALSA]]
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</noinclude>

2020年5月7日 (四) 11:12的版本

Article purpose

This article introduces the SPDIFRX Linux® driver for the SPDIFRX internal peripheral.

Short Description

The SPDIFRX[1] Linux driver is an ASoC CPU DAI driver implemented in the Linux ALSA framework.

Configuration

Kernel Configuration

Activate the SPDIFRX[1] Linux driver in the kernel configuration using the Linux Menuconfig tool: Menuconfig or how to configure kernel

[*] 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

Device tree

Refer to the SPDIFRX device tree configuration article when configuring the SPDIFRX Linux kernel driver.

How to use

The SPDIFRX driver is accessed from userland through an ALSA device. Refer to ALSA overview to see how to list and use ALSA devices.

The SPDFIRX driver exposes an alsa control, which allows to retrieve the IEC958 status bits from the input audio stream.

Warning.png The configuration of the SPDIFRX input pin in the device tree, may put some restrictions on the use of IEC958 control. Thus, in some configuration, the control can be used only when an audio stream is captured. Refer to the SPDIFRX device tree configuration article, to find details about SPDIFRX configuration.

How to debug

The 调试文件系统(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 to get more details about debugging tools.

  • debugfs entries:
$ cat /sys/kernel/debug/regmap/xxx.audio-controller/registers
  • procfs entries:
$ cat /proc/interrupts

Source code location

sound/soc/stm/stm32_spdifrx.c| |}} sound/soc/stm/stm32_spdifrx.c : implements the SPDIFRX driver.

References


<securetransclude src="ProtectedTemplate:ArticleBasedOnModel" params="Peripheral or framework device tree configuration model"></securetransclude> {{PublicationRequestId | 9234 | 2018-10-22 | BrunoB}