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High quality Raspberry Pi I2S HAT - part 5 - linux kernel patching

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Kernel patching


At last, in order to make I2S Hat working properly you have to recompile the kernel.

Firstly download kernel source files, suitable to your distribution.
Secondly you can download the patches here. Copy and unpack in top directory kernel source.

What are the patches doing?

Here is the list:
  1. p1.patch - support for 384k in file ./sound/core/pcm_native.c
  2. p2.patch - support for 384 in file ./include/sound/pcm.h
  3. p3.patch - support for 384k in file ./sound/soc/codecs/pcm1794a.c
  4. p4.patch - gpio config in file ./arch/arm/boot/dts/overlays/rpi-dac-overlay.dts
  5. p5.patch - main driver file ./sound/soc/bcm/rpi-simple-soundcard.c
  6. p6.patch - support for 384k in file ./drivers/staging/vc04_services/bcm2835-audio/bcm2835-pcm.c
To apply the patch you can use patch command as below:

patch -p1 -i p1.patch

Repeat this for all six patches.

Then recompile and install new kernel and modules.

Don't forget to add the line to config.txt











Thats all :)

Comments

  1. wiskiAugust 1, 2024 at 12:57 AM

    Very interesting project, thanks, I am wanting to just turn the RPI into a slave for I2S and use a legacy TDA1541 DAC where the clock source (master) is a Philips SAA220. What I'm ot sureof is which parts of your blog refer to the part I need and which parts are linked to your choice of Hat.

    ReplyDelete

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