Messages in this thread | | | Date | Tue, 5 Sep 2017 11:11:09 -0700 | From | Nicolin Chen <> | Subject | Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq |
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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?
> 2. 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.
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