From: broonie@kernel.org (Mark Brown)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCHv2 1/8] ALSA: Add SAI SoC Digital Audio Interface driver.
Date: Mon, 4 Nov 2013 08:15:37 -0800 [thread overview]
Message-ID: <20131104161537.GI2493@sirena.org.uk> (raw)
In-Reply-To: <1DD289F6464F0949A2FCA5AA6DC23F8287439D@039-SN2MPN1-013.039d.mgd.msft.net>
On Mon, Nov 04, 2013 at 07:35:12AM +0000, Li Xiubo wrote:
> From the ASoC subsystem comments we can see that:
> ++++++
> Configures the clock dividers. This is used to derive the best DAI bit and
> frame clocks from the system or master clock. It's best to set the DAI bit
> and frame clocks as low as possible to save system power.
> ------
You should never use this unless you have to, there is no point in every
single machine driver using your driver having to duplicate the same
calculations.
>
> > > +static int fsl_sai_dai_probe(struct snd_soc_dai *dai) {
> > > + int ret;
> > > + struct fsl_sai *sai = dev_get_drvdata(dai->dev);
> > > +
> > > + ret = clk_prepare_enable(sai->clk);
> > > + if (ret)
> > > + return ret;
> > It'd be nicer to only enable the clock while the device is in active use.
> While if the module clock is not enabled here, the followed registers cannot read/write in the same function.
> And this _probe function is the _dai_probe not the driver's module _probe.
So you can enable the clock when you explicitly need to write to the
registers...
> If the clk_prepare_enable(sai->clk) is not here, where should it be will be nicer ?
> One of the following functions ?
> .set_sysclk = fsl_sai_set_dai_sysclk,
> .set_clkdiv = fsl_sai_set_dai_clkdiv,
> .set_fmt = fsl_sai_set_dai_fmt,
> .set_tdm_slot = fsl_sai_set_dai_tdm_slot,
> .hw_params = fsl_sai_hw_params,
> .trigger = fsl_sai_trigger,
It could be in any or all of them except trigger (where the core should
hold a runtime PM reference anyway). You can always take a reference
for the duration of the function if you're concerned it may be called
when the referent isn't otherwise held.
> > > + ret = snd_dmaengine_pcm_register(&pdev->dev, NULL,
> > > + SND_DMAENGINE_PCM_FLAG_NO_RESIDUE);
> > > + if (ret)
> > > + return ret;
> > We should have a devm_ version of this.
> Sorry, is there one patch for adding the devm_ version of snd_dmaengine_pcm_register() already ?
> In the -next and other topics branches I could not find it.
No, there isn't one but there should be one.
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next prev parent reply other threads:[~2013-11-04 16:15 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-01 7:04 No subject Xiubo Li
2013-11-01 7:04 ` [PATCHv2 1/8] ALSA: Add SAI SoC Digital Audio Interface driver Xiubo Li
2013-11-01 8:59 ` Nicolin Chen
2013-11-04 3:45 ` Li Xiubo
2013-11-04 4:33 ` Nicolin Chen
2013-11-20 3:37 ` Li Xiubo
2013-11-20 3:37 ` Nicolin Chen
2013-11-20 4:16 ` Li Xiubo
2013-11-05 13:26 ` Timur Tabi
2013-11-06 3:27 ` Li Xiubo
2013-11-06 3:31 ` Timur Tabi
2013-11-06 3:53 ` Li Xiubo
2013-11-06 8:12 ` Shawn Guo
2013-11-06 9:38 ` Li Xiubo
2013-11-01 18:25 ` Mark Brown
2013-11-04 7:35 ` Li Xiubo
2013-11-04 16:15 ` Mark Brown [this message]
2013-11-05 3:21 ` Li Xiubo
2013-11-06 9:53 ` Mark Brown
2013-11-01 7:04 ` [PATCHv2 2/8] ARM: dts: Add Freescale SAI ALSA SoC Digital Audio Interface node for VF610 Xiubo Li
2013-11-01 7:04 ` [PATCHv2 3/8] ARM: dts: Enables SAI ALSA SoC DAI device for Vybrid VF610 TOWER board Xiubo Li
2013-11-18 18:07 ` Bill Pringlemeir
2013-11-20 3:14 ` Li Xiubo
2013-11-20 16:04 ` Bill Pringlemeir
2013-11-21 2:58 ` Li Xiubo
2013-11-21 14:55 ` Bill Pringlemeir
2013-11-22 6:46 ` Li Xiubo
2013-11-22 15:09 ` Bill Pringlemeir
2013-11-28 7:45 ` Li Xiubo
2013-11-01 7:04 ` [PATCHv2 4/8] Documentation: Add device tree bindings for Freescale SAI Xiubo Li
2013-11-01 7:04 ` [PATCHv2 5/8] ASoC: SGTL5000: Enhance the SGTL5000 codec driver about regulator Xiubo Li
2013-11-01 10:02 ` Nicolin Chen
2013-11-01 18:50 ` Mark Brown
2013-11-06 8:59 ` Li Xiubo
2013-11-06 10:03 ` Mark Brown
2013-11-07 3:01 ` Li Xiubo
2013-11-07 20:38 ` Mark Brown
2013-11-01 7:04 ` [PATCHv2 6/8] ASoC: fsl: add SGTL5000 based audio machine driver Xiubo Li
2013-11-01 10:17 ` Oskar Schirmer
2013-11-05 3:26 ` Li Xiubo
2013-11-01 10:28 ` Nicolin Chen
2013-11-01 12:07 ` Shawn Guo
2013-11-05 6:17 ` Li Xiubo
2013-11-05 3:50 ` Li Xiubo
2013-11-01 18:40 ` Mark Brown
2013-11-04 9:52 ` Li Xiubo
2013-11-20 7:49 ` Li Xiubo
2013-11-01 7:04 ` [PATCHv2 7/8] ARM: dts: Enable SGTL5000 codec based audio driver node for VF610 Xiubo Li
2013-11-01 7:04 ` [PATCHv2 8/8] Documentation: Add device tree bindings for Freescale VF610 sound Xiubo Li
2013-11-01 7:52 ` [PATCHv1 0/8] ALSA: Add SAI driver and enable SGT15000 codec Li Xiubo
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