Messages in this thread | | | Date | Wed, 10 Sep 2014 12:53:59 +0200 | From | Markus Pargmann <> | Subject | Re: [PATCH V1] ASoC: fsl_ssi: refine ipg clock usage in this module |
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Hi,
On Wed, Sep 10, 2014 at 06:30:06PM +0800, Shengjiu Wang wrote: > On Wed, Sep 10, 2014 at 08:21:18AM +0200, Markus Pargmann wrote: > > On Tue, Sep 09, 2014 at 11:38:05AM -0700, Nicolin Chen wrote: > > > On Tue, Sep 09, 2014 at 05:18:07PM +0800, Shengjiu Wang wrote: > > > > @@ -1321,7 +1333,11 @@ static int fsl_ssi_probe(struct platform_device *pdev) > > > > return -ENOMEM; > > > > } > > > > > > > > - ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem, > > > > + if (ssi_private->soc->imx) > > > > + ssi_private->regs = devm_regmap_init_mmio_clk(&pdev->dev, > > > > + "ipg", iomem, &fsl_ssi_regconfig); > > > > + else > > > > + ssi_private->regs = devm_regmap_init_mmio(&pdev->dev, iomem, > > > > > > As Markus mentioned, the key point here is to be compatible with those > > > non-clock-name platforms. > > > > > > I think it would be safer to keep the current code while adding an extra > > > clk_disable_unprepare() at the end of probe() as a common routine. And > > > meantime, make sure to have the call for imx only because it seems that > > > the other platforms do not depend on the clock. //a bit guessing here :) > > > > > > Then we can get a patch like: > > > open() { > > > + clk_prepare_enable(); > > > .... > > > } > > > > > > close() { > > > .... > > > + clk_disable_unprepare() > > > } > > > > > > probe() { > > > clk_get(); > > > clk_prepare_enable(); > > > .... > > > if (xxx) > > > - goto err_xx; > > > + return ret; > > > .... > > > + clk_disable_unprepare(); > > > return 0; > > > -err_xx: > > > - clk_disable_unprepare() > > > } > > > > > > remove() { > > > .... > > > - clk_disable_unprepare() > > > } > > > > If I remember correctly, there may be AC97 communication with the codec > > before any substream is created. That's why we enable the SSI unit right > > at the beginning for AC97 in fsl_ssi_setup_reg_vals(). So we need to > > check for AC97 before disabling clocks. > > > > Best regards, > > > > Markus > > hi Markus > > I think if clk_prepare_enable() in startup(), and clk_disable_unprepare() > in shutdown can meet this requirement, right?
Yes that could work.
> > done: > if (ssi_private->dai_fmt) > _fsl_ssi_set_dai_fmt(ssi_private, ssi_private->dai_fmt); > > I find that in end of probe, there is setting of dai_fmt. Can we remove this? > because this setting need to enable ipg clock, and if ac97, ipg clock can't be > disabled.
No you can't remove it. It is necessary for the DT property "fsl,mode". Most dts do not have this property anymore because the sound cards are setting the dai-fmt. But there are still some powerpc dts files that contain that property.
Best regards,
Markus
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