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Groups > linux.kernel > #1727665
| From | Nicolin Chen <nicoleotsuka@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq |
| Date | 2017-09-06 19:50 +0200 |
| Message-ID | <umMCB-53y-3@gated-at.bofh.it> (permalink) |
| References | (4 earlier) <umhyO-kE-17@gated-at.bofh.it> <umqC6-6kM-7@gated-at.bofh.it> <umtqh-8fp-9@gated-at.bofh.it> <umuZ3-IG-15@gated-at.bofh.it> <umEOJ-85j-1@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, Sep 06, 2017 at 11:22:48AM +0200, Łukasz Majewski wrote:
> >Here is the routine that I understood from the code:
> >1) asoc_simple_card_parse_clk_cpu(dev, cpu, dai_link, cpu_dai);
> > => asoc_simple_card_parse_clk(dev, cpu, // cpu node in sound{} [1]
> > dai_link->cpu_of_node, // node ssi2 [2]
> > cpu_dai, dai_link->cpu_dai_name);
> > ==> 1.1) devm_get_clk_from_child(dev, node, NULL); // [1]
> > ==> 1.2) of_property_read_u32(node, "system-clock-frequency", &val)// [1]
> > ==> 1.3) devm_get_clk_from_child(dev, dai_of_node, NULL); // [2]
> >For the cpu routine, it first checks for clock property under cpu
> >node of simple-card, then for "system-clock-frequency" in the cpu
> >node of simple-card, and finally looks for clock property in ssi2
> >node.
> -----> dev: sound
> -----> clk node: /soc/aips-bus@02000000/spba-bus@02000000/ssi@0202c000
> -----> Clk asignment
>
> And this clock is taken from this node. It looks like ipg clock for ssi...
This makes sense now. The devm_get_clk_from_child() in 1.3) fetched
the first clock of ssi2 -- ipg clock.
> The problem is with the "lack" of clock nodes/properties at
>
> dailink_master: cpu {
> sound-dai = <&ssi2>;
> clock = <&SSSS>;
> system-clock-frequency = <XXXX>;
> };
This is the right solution based on current simple-card driver. For
SSI (having two clocks), you have to specify the baud clock in the
cpu node like that. I believe this is what the simple-card designer
expected users to do since the cpu node is the first place that the
driver tries to look at.
> I think that the proper solution would be to add check for:
>
> freq < sysclk/5 in fsl_ssi_set_dai_sysclk() and return -ENOTSUPP to
> make the simple-audo-card driver happy (and not introducing
> regressions).
As I said in the first place, adding another check in set_sysclk()
is not that essential but seems to be plausible to me. So I am okay
if you really want to have that.
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[PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Lukasz Majewski <lukma@denx.de> - 2017-09-03 13:10 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-03 16:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Fabio Estevam <festevam@gmail.com> - 2017-09-03 17:40 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-05 07:30 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-05 10:40 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-05 20:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-05 23:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-06 01:00 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-06 11:30 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-06 19:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-06 20:40 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-06 21:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-06 23:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-08 01:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-08 02:40 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Fabio Estevam <festevam@gmail.com> - 2017-09-06 01:30 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-06 10:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Fabio Estevam <festevam@gmail.com> - 2017-09-05 22:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-05 23:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-05 07:10 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-05 09:40 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-05 10:00 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Łukasz Majewski <lukma@denx.de> - 2017-09-05 10:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Mark Brown <broonie@kernel.org> - 2017-09-05 17:20 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-05 19:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Mark Brown <broonie@kernel.org> - 2017-09-07 15:50 +0200
Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Nicolin Chen <nicoleotsuka@gmail.com> - 2017-09-08 01:10 +0200
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