From: Nicolin Chen <nicoleotsuka@gmail.com> To: "Łukasz Majewski" <lukma@denx.de> Cc: Fabio Estevam <fabio.estevam@nxp.com>, Timur Tabi <timur@tabi.org>, Xiubo Li <Xiubo.Lee@gmail.com>, Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>, Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>, "festevam@gmail.com" <festevam@gmail.com>, "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>, "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Date: Wed, 6 Sep 2017 10:33:50 -0700 [thread overview] Message-ID: <20170906173348.GA28104@Asurada-Nvidia> (raw) In-Reply-To: <ae1d3e2a-d618-05e2-1572-5593caff1ee0@denx.de> 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.
WARNING: multiple messages have this Message-ID (diff)
From: Nicolin Chen <nicoleotsuka@gmail.com> To: "Łukasz Majewski" <lukma@denx.de> Cc: "alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>, Timur Tabi <timur@tabi.org>, Xiubo Li <Xiubo.Lee@gmail.com>, "linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>, Takashi Iwai <tiwai@suse.com>, Liam Girdwood <lgirdwood@gmail.com>, Mark Brown <broonie@kernel.org>, Fabio Estevam <fabio.estevam@nxp.com>, "festevam@gmail.com" <festevam@gmail.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Date: Wed, 6 Sep 2017 10:33:50 -0700 [thread overview] Message-ID: <20170906173348.GA28104@Asurada-Nvidia> (raw) In-Reply-To: <ae1d3e2a-d618-05e2-1572-5593caff1ee0@denx.de> 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. _______________________________________________ Alsa-devel mailing list Alsa-devel@alsa-project.org http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
next prev parent reply other threads:[~2017-09-06 17:41 UTC|newest] Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top 2017-09-03 11:05 [PATCH] sound: soc: fsl: Do not set DAI sysclk when it is equal to system freq Lukasz Majewski 2017-09-03 12:44 ` Fabio Estevam 2017-09-03 12:44 ` Fabio Estevam 2017-09-03 14:40 ` Łukasz Majewski 2017-09-03 15:29 ` Fabio Estevam 2017-09-03 15:29 ` Fabio Estevam 2017-09-03 15:29 ` Fabio Estevam 2017-09-05 5:20 ` Nicolin Chen 2017-09-05 8:35 ` Łukasz Majewski 2017-09-05 18:11 ` Nicolin Chen 2017-09-05 21:13 ` Łukasz Majewski 2017-09-05 21:13 ` Łukasz Majewski 2017-09-05 22:52 ` Nicolin Chen 2017-09-05 22:52 ` Nicolin Chen 2017-09-06 9:22 ` Łukasz Majewski 2017-09-06 9:22 ` Łukasz Majewski 2017-09-06 17:33 ` Nicolin Chen [this message] 2017-09-06 17:33 ` Nicolin Chen 2017-09-06 18:35 ` Łukasz Majewski 2017-09-06 19:47 ` Nicolin Chen 2017-09-06 19:47 ` Nicolin Chen 2017-09-06 21:18 ` Łukasz Majewski 2017-09-06 21:18 ` Łukasz Majewski 2017-09-07 23:10 ` Łukasz Majewski 2017-09-07 23:10 ` Łukasz Majewski 2017-09-08 0:39 ` Nicolin Chen 2017-09-08 0:39 ` Nicolin Chen 2017-09-05 23:20 ` Fabio Estevam 2017-09-05 23:20 ` Fabio Estevam 2017-09-05 23:20 ` Fabio Estevam 2017-09-06 8:44 ` Łukasz Majewski 2017-09-05 20:14 ` Fabio Estevam 2017-09-05 20:14 ` Fabio Estevam 2017-09-05 21:14 ` Łukasz Majewski 2017-09-05 5:06 ` Nicolin Chen 2017-09-05 7:37 ` Łukasz Majewski 2017-09-05 7:52 ` Nicolin Chen 2017-09-05 8:19 ` Łukasz Majewski 2017-09-05 8:19 ` Łukasz Majewski 2017-09-05 15:15 ` Mark Brown 2017-09-05 15:15 ` Mark Brown 2017-09-05 17:45 ` Nicolin Chen 2017-09-07 13:44 ` Mark Brown 2017-09-07 13:44 ` Mark Brown 2017-09-07 23:03 ` Nicolin Chen
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