Subject: [PATCH v4 2/2] usb: chipidea: imx: refine clock operations to adapt for all platforms

From: [email-masked] (Peter Chen)
Date: Wed, 14 Oct 2015 17:14:47 +0800

On Wed, Oct 14, 2015 at 10:07:59AM +0200, Marc Kleine-Budde wrote:
> On 10/14/2015 03:57 AM, Peter Chen wrote:
> > Some i.mx platforms need three clocks to let controller work, but
> > others only need one, refine clock operation to adapt for all
> > platforms, it fixes a regression found at i.mx27.
> > 
> > Signed-off-by: Peter Chen <[email-masked]>
> > Tested-by: Fabio Estevam <[email-masked]>
> > Cc: <[email-masked]> #v4.1+
> > ---
> >  drivers/usb/chipidea/ci_hdrc_imx.c | 132 ++++++++++++++++++++++++++++++++-----
> >  1 file changed, 114 insertions(+), 18 deletions(-)
> > 
> > diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> > index 6ccbf60..82b1dfe 100644
> > --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> > +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> > @@ -84,6 +84,12 @@ struct ci_hdrc_imx_data {
> >  	struct imx_usbmisc_data *usbmisc_data;
> >  	bool supports_runtime_pm;
> >  	bool in_lpm;
> > +	/* SoC before i.mx6 (except imx23/imx28) needs three clks */
> > +	bool need_three_clks;
> > +	struct clk *clk_ipg;
> > +	struct clk *clk_ahb;
> > +	struct clk *clk_per;
> > +	/* --------------------------------- */
> >  };
> >  
> >  /* Common functions shared by usbmisc drivers */
> > @@ -135,6 +141,103 @@ static struct imx_usbmisc_data *usbmisc_get_init_data(struct device *dev)
> >  }
> >  
> >  /* End of common functions shared by usbmisc drivers*/
> > +static int imx_get_clks(struct device *dev)
> > +{
> > +	struct ci_hdrc_imx_data *data = dev_get_drvdata(dev);
> > +	int ret = 0;
> > +
> > +	data->clk_ipg = devm_clk_get(dev, "ipg");
> > +	if (IS_ERR(data->clk_ipg)) {
> > +		/* If the platform only needs one clocks */
> > +		data->clk = devm_clk_get(dev, NULL);
> > +		if (IS_ERR(data->clk)) {
> > +			ret = PTR_ERR(data->clk);
> > +			dev_err(dev,
> > +				"Failed to get clock, err=%d\n", ret);
> > +			dev_err(dev,
> > +				"Failed to get ipg clock, err=%d\n", ret);
> 
> Nitpick, one error message should be enough.

Yes, I will show both error value for clk_ipg and NULL.

> 
> > +			return ret;
> > +		}
> > +		return ret;
> > +	}
> > +
> > +	data->clk_ahb = devm_clk_get(dev, "ahb");
> > +	if (IS_ERR(data->clk_ahb)) {
> > +		ret = PTR_ERR(data->clk_ahb);
> > +		dev_err(dev,
> > +			"Failed to get ahb clock, err=%d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	data->clk_per = devm_clk_get(dev, "per");
> > +	if (IS_ERR(data->clk_per)) {
> > +		ret = PTR_ERR(data->clk_per);
> > +		dev_err(dev,
> > +			"Failed to get per clock, err=%d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	data->need_three_clks = true;
> > +	return ret;
> > +}
> > +
> > +static int imx_prepare_enable_clks(struct device *dev)
> > +{
> > +	struct ci_hdrc_imx_data *data = dev_get_drvdata(dev);
> > +	int ret = 0;
> > +
> > +	if (data->need_three_clks) {
> > +		ret = clk_prepare_enable(data->clk_ipg);
> > +		if (ret) {
> > +			dev_err(dev,
> > +				"Failed to prepare/enable ipg clk, err=%d\n",
> > +				ret);
> > +			return ret;
> > +		}
> > +
> > +		ret = clk_prepare_enable(data->clk_ahb);
> > +		if (ret) {
> > +			dev_err(dev,
> > +				"Failed to prepare/enable ahb clk, err=%d\n",
> > +				ret);
> > +			clk_disable_unprepare(data->clk_ipg);
> > +			return ret;
> > +		}
> > +
> > +		ret = clk_prepare_enable(data->clk_per);
> > +		if (ret) {
> > +			dev_err(dev,
> > +				"Failed to prepare/enable per clk, err=%d\n",
> > +				ret);
> > +			clk_disable_unprepare(data->clk_ahb);
> > +			clk_disable_unprepare(data->clk_ipg);
> > +			return ret;
> > +		}
> > +	} else {
> > +		ret = clk_prepare_enable(data->clk);
> > +		if (ret) {
> > +			dev_err(dev,
> > +				"Failed to prepare/enable clk, err=%d\n",
> > +				ret);
> > +			return ret;
> > +		}
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> > +static void imx_disable_unprepare_clks(struct device *dev)
> > +{
> > +	struct ci_hdrc_imx_data *data = dev_get_drvdata(dev);
> > +
> > +	if (data->need_three_clks) {
> > +		clk_disable_unprepare(data->clk_per);
> > +		clk_disable_unprepare(data->clk_ipg);
> > +		clk_disable_unprepare(data->clk_ahb);
> 
> nit: you enable in this order: ipg, ahb, per. Disabling should be inverse.

Will change, thanks.

> 
> > +	} else {
> > +		clk_disable_unprepare(data->clk);
> > +	}
> > +}

-- 

Best Regards,
Peter Chen