On Tue, Sep 05, 2017 at 10:35:34AM +0200, Łukasz Majewski wrote:
And apparently, we shouldn't set bitclk to 66MHz either. Can you help to find where this 66MHz comes from?
- int asoc_simple_card_init_dai() @ simple-card-utils.c
Oh, I just searched in the simple-card.c but missed this file.
In this function (point 2.) the simple_dai->sysclk is set and: snd_soc_dai_set_sysclk(dai, 0, simple_dai->sysclk, 0) which sets frequency to 66 MHz [*].
The asoc_simple_card_init_dai() is called in asoc_simple_card_dai_init() @ simple-card.c which is assigned to dai_link->init dai_link->init = asoc_simple_card_dai_init; @ simple_card.c
And the sysclk itself is defined at:
dai_props->codec_dai->sysclk, which is used at:a
Why codec_dai? Why not dai_props->cpu_dai->sysclk since we are talking about SSI?
asoc_simple_card_startup(), asoc_simple_card_shutdown() and others functions at simple-card.c It is setup at: asoc_simple_card_parse_clk() @ simple-card-utils.c from macro: #define asoc_simple_card_parse_clk_cpu() And the problem is:
At the asoc_simple_card_parse_clk() we finally go to dts node: /soc/aips-bus@02100000/i2c@021a0000/tfa9879@6C
This tfa9879 should be the CODEC right?
which has clock from I2C (66 MHz).
You mean I2C scl or I2S sclk?
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But anyway, I feel very confused here as you have 66MHz clock rate (regardless of it purpose) for a codec dai but it's been passed to a cpu dai (SSI).
[*] - I could workaround this problem by setting:
system-clock-frequency = <0> in
dailink_master: cpu { sound-dai = <&ssi2>; };but this is IMHO even worse hack.... than this patch.
I haven't used simple-card for a while so I forgot how to define its DT bindings specifically. But you should assign ssi2 as the CPU dai and assign tfa9879 as a CODEC dai.