linux-kernel - Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err

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Message-ID: <Zy0Z3wIsgX+O4DEw@lizhi-Precision-Tower-5810>
Date: Thu, 7 Nov 2024 14:49:51 -0500
From: Frank Li <Frank.li@....com>
To: Christophe JAILLET <christophe.jaillet@...adoo.fr>
Cc: Haibo Chen <haibo.chen@....com>, Jonathan Cameron <jic23@...nel.org>,
	Lars-Peter Clausen <lars@...afoo.de>, linux-iio@...r.kernel.org,
	imx@...ts.linux.dev,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and
 dev_err_probe() to simple code

On Thu, Nov 07, 2024 at 08:38:20PM +0100, Christophe JAILLET wrote:
> Le 07/11/2024 à 20:18, Frank Li a écrit :
> > Use devm_* and dev_err_probe() simplify probe function and remove
> > vf610_adc_remove(). Change type of 'vref_uv' to int because
> > regulator_get_voltage() return type is int.
> >
> > Reviewed-by: Haibo Chen <haibo.chen-3arQi8VN3Tc@...lic.gmane.org>
> > Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc@...lic.gmane.org>
> > ---
> > Change from v2 to v3
> > - change vref_uv to int from u32 to fix below warning
> > | Reported-by: kernel test robot <lkp-ral2JQCrhuEAvxtiuMwx3w@...lic.gmane.org>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202411070633.NIrO7Ert-lkp-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org/
> > smatch warnings:
> > drivers/iio/adc/vf610_adc.c:857 vf610_adc_probe() warn: unsigned 'info->vref_uv' is never less than zero.
> >
> > vim +857 drivers/iio/adc/vf610_adc.c
> >
> > Change from v1 to v2
> > - add Haibo's review tag
> > ---
> >   drivers/iio/adc/vf610_adc.c | 79 ++++++++++---------------------------
> >   1 file changed, 20 insertions(+), 59 deletions(-)
> >
> > diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
> > index 4d83c12975c53..a6a0ada8a102f 100644
> > --- a/drivers/iio/adc/vf610_adc.c
> > +++ b/drivers/iio/adc/vf610_adc.c
> > @@ -160,7 +160,7 @@ struct vf610_adc {
> >   	/* lock to protect against multiple access to the device */
> >   	struct mutex lock;
> > -	u32 vref_uv;
> > +	int vref_uv;
> >   	u32 value;
> >   	struct regulator *vref;
> > @@ -823,10 +823,8 @@ static int vf610_adc_probe(struct platform_device *pdev)
> >   	int ret;
> >   	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(struct vf610_adc));
> > -	if (!indio_dev) {
> > -		dev_err(&pdev->dev, "Failed allocating iio device\n");
> > -		return -ENOMEM;
> > -	}
> > +	if (!indio_dev)
> > +		return dev_err_probe(&pdev->dev, -ENOMEM, "Failed allocating iio device\n");
> >   	info = iio_priv(indio_dev);
> >   	info->dev = &pdev->dev;
> > @@ -842,27 +840,22 @@ static int vf610_adc_probe(struct platform_device *pdev)
> >   	ret = devm_request_irq(info->dev, irq,
> >   				vf610_adc_isr, 0,
> >   				dev_name(&pdev->dev), indio_dev);
> > -	if (ret < 0) {
> > -		dev_err(&pdev->dev, "failed requesting irq, irq = %d\n", irq);
> > -		return ret;
> > -	}
> > +	if (ret < 0)
> > +		dev_err_probe(&pdev->dev, ret, "failed requesting irq, irq = %d\n", irq);
>
> missing return?

Yes, thank you find it.

>
> > -	info->clk = devm_clk_get(&pdev->dev, "adc");
> > -	if (IS_ERR(info->clk)) {
> > -		dev_err(&pdev->dev, "failed getting clock, err = %ld\n",
> > -						PTR_ERR(info->clk));
> > -		return PTR_ERR(info->clk);
> > -	}
> > +	info->clk = devm_clk_get_enabled(&pdev->dev, "adc");
> > +	if (IS_ERR(info->clk))
> > +		return dev_err_probe(&pdev->dev, PTR_ERR(info->clk),
> > +				     "failed getting clock, err = %ld\n",
> > +				     PTR_ERR(info->clk));
>
> No need to add an extra PTR_ERR(info->clk)

yes, dev_err_probe() already print error code. So "err= %ld" can be removed
also.

>
> >   	info->vref = devm_regulator_get(&pdev->dev, "vref");
>
> With the change to devm_regulator_get_enable_read_voltage(), is it still
> needed?

Suspend function need vref to disable regulator.

>
> CJ
>
> >   	if (IS_ERR(info->vref))
> >   		return PTR_ERR(info->vref);
> > -	ret = regulator_enable(info->vref);
> > -	if (ret)
> > -		return ret;
> > -
> > -	info->vref_uv = regulator_get_voltage(info->vref);
> > +	info->vref_uv = devm_regulator_get_enable_read_voltage(&pdev->dev, "vref");
> > +	if (info->vref_uv < 0)
> > +		return info->vref_uv;
> >   	device_property_read_u32_array(dev, "fsl,adck-max-frequency", info->max_adck_rate, 3);
>
> ...
>