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Title: Question about I2S audio output [Print This Page]

Author: cgsong Time: 12/8/2014 14:33
Title: Question about I2S audio output

The Firefly RK3288's PCM mode works well, but I want to use I2S audio output with ALSA. I don't know how to configure ES8323 I2S output mode. Please let me know the configuration for the I2S audio output.

Thanks.

?

Author: Developer_X Time: 12/9/2014 09:28
en,,,I am also not goot at this.

You can try to view RKDocs,Good luck!

Author: isle Time: 12/9/2014 11:08
│ Symbol: SND_RK_SOC_ES8323 [=y]                                                                                                       │
  │ Type  : tristate                                                                                                                      │
  │ Prompt: SoC I2S Audio support for rockchip - ES8323                                                                                  │
  │ Location:                                                                                                                         │
  │    -> Device Drivers                                                                                                                │
  │    -> Sound card support (SOUND [=y])                                                                                              │
  │       -> Advanced Linux Sound Architecture (SND [=y])                                                                               │
  │ (1)    -> ALSA for SoC audio support (SND_SOC [=y])                                                                               │
  │ Defined at sound/soc/rockchip/Kconfig:54                                                                                           │
  │ Depends on: SOUND [=y] && !M68K && !UML && SND [=y] && SND_SOC [=y] && SND_RK_SOC [=y]                                              │

│ Selects: SND_RK_SOC_I2S [=y] && SND_SOC_ES8323 [=y]

Author: cgsong Time: 12/9/2014 12:20

As you know default kernel image that Firefly provides is ES8323 PCM output. In the kernel compile configuration, there are two options "SoC I2S Audio support for rockchip -ES8323" and "Soc I2S Audio Support for rockchip - ES8323 for PCM modem". So you suggest that I should compile "SoC I2S Audio support for rockchip - ES8323" option. Is it right? Default kernel device driver in ALSA always provide PCM output and that's why I was wondering about using I2S mode.

Author: isle Time: 12/9/2014 17:55

Yes!

i use the i2s mode and it works well 。

Author: cgsong Time: 12/12/2014 23:49

I compiled kernel with "SoC I2S Audio support for rockchip -ES8323" option. But I can't see the I2S driver in Unbuntu. When I list with "aplay -l" command, I see the following devices. There is no I2S driver for ES8323. Could you help me how to setup I2S?

**** List of PLAYBACK Hardware Devices ****

card 0: RKES8323 [RK_ES8323], device 0: ES8323 PCM ES8323 HiFi-0 []

Subdevices: 1/1

Subdevice #0: subdevice #0

card 1: RKHDMISPDIF [RK-HDMI-SPDIF], device 0: SPDIF PCM Playback rk-hdmi-spdif-hifi-0 []

Subdevices: 1/1

Subdevice #0: subdevice #0

Author: isle Time: 12/13/2014 10:29
As I know , the ES8323 PCM mode & I2S mode are the different serial audio data interface.

it is just a transport type between MCU and Audio codec .

you can check it on the document of ES8323_DS.pdf which can be downloaded on our website.

and here :

"The device provides four formats of serial audio data interface to the input of the DAC or output from the ADC through LRCK, SCLK and SDIN/SDOUT pins. The four formats are I2S, left justified, right justified and DSP/PCM mode."

here is the figure of the I2S mode format：

and the pcm mode ：

and both of them are delivered the PCM DATA .

So ,I guees the “PCM” from the "aplay -l" command means the “PCM DATA”， not the interface。

however, I'm not very sure about it .please tell me if I was wrong.

Author: cgsong Time: 12/17/2014 10:11
I try to connect my PCM5102 DAC through I2S into Firefly Rk3288's GPIO6 I2S pin. But I still can't connect I2S device from GPIO6 I2S at Firefly. Stereo output at Firefly is working but I want a i2s output from Firefly. When I see "/proc/i2s_reg", there is no register values, so I think i2s device driver is not loaded. I2S device driver file which is "kernel/sound/soc/rockchip/rk30_i2s.c" is compiled, but I think it is not loaded. How can I output i2s signal from GPIO6 at Firefly to my PCM5102 I2S device?

Author: isle Time: 12/18/2014 15:20
hi , the firefly board use the es8323 as default Aduio DAC , it's also connect to the I2S0(GPIO6). so.you would do nothing to get I2S out from I2S0(GPIO6).

Author: mbt28 Time: 3/12/2015 20:51
Hi,

In the datasheet of RK3288 it says that PCM and I2S cannot be used together. I think somehow you should disable the built in from the kernel and run through I2S. As far as I see it is 8ch I2S with outs and ins.

Well can you check lsmod?

Regards.

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