[PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Frank Li]

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@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Change from v2 to v3
- change vref_uv to int from u32 to fix below warning
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411070633.NIrO7Ert-lkp@intel.com/
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);
 
-	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));
 
 	info->vref = devm_regulator_get(&pdev->dev, "vref");
 	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);
 
@@ -879,52 +872,21 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	indio_dev->channels = vf610_adc_iio_channels;
 	indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
 
-	ret = clk_prepare_enable(info->clk);
-	if (ret) {
-		dev_err(&pdev->dev,
-			"Could not prepare or enable the clock.\n");
-		goto error_adc_clk_enable;
-	}
-
 	vf610_adc_cfg_init(info);
 	vf610_adc_hw_init(info);
 
-	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
-					NULL, &iio_triggered_buffer_setup_ops);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Couldn't initialise the buffer\n");
-		goto error_iio_device_register;
-	}
+	ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, &iio_pollfunc_store_time,
+					      NULL, &iio_triggered_buffer_setup_ops);
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "Couldn't initialise the buffer\n");
 
 	mutex_init(&info->lock);
 
-	ret = iio_device_register(indio_dev);
-	if (ret) {
-		dev_err(&pdev->dev, "Couldn't register the device.\n");
-		goto error_adc_buffer_init;
-	}
+	ret = devm_iio_device_register(&pdev->dev, indio_dev);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Couldn't register the device.\n");
 
 	return 0;
-
-error_adc_buffer_init:
-	iio_triggered_buffer_cleanup(indio_dev);
-error_iio_device_register:
-	clk_disable_unprepare(info->clk);
-error_adc_clk_enable:
-	regulator_disable(info->vref);
-
-	return ret;
-}
-
-static void vf610_adc_remove(struct platform_device *pdev)
-{
-	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
-	struct vf610_adc *info = iio_priv(indio_dev);
-
-	iio_device_unregister(indio_dev);
-	iio_triggered_buffer_cleanup(indio_dev);
-	regulator_disable(info->vref);
-	clk_disable_unprepare(info->clk);
 }
 
 static int vf610_adc_suspend(struct device *dev)
@@ -972,7 +934,6 @@ static DEFINE_SIMPLE_DEV_PM_OPS(vf610_adc_pm_ops, vf610_adc_suspend,
 
 static struct platform_driver vf610_adc_driver = {
 	.probe          = vf610_adc_probe,
-	.remove         = vf610_adc_remove,
 	.driver         = {
 		.name   = DRIVER_NAME,
 		.of_match_table = vf610_adc_match,
-- 
2.34.1

[PATCH v3 2/2] iio: adc: vf610_adc: limit i.MX6SX's channel number to 4

[Frank Li]

i.MX6SX only has 4 ADC channels, so limit channel numbers to 4 for
compatible string 'fsl,imx6sx-adc'.

Reviewed-by: Haibo Chen <haibo.chen@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
compatible string 'fsl,imx6sx-adc' already document in
Documentation/devicetree/bindings/iio/adc/fsl,vf610-adc.yaml

Change from v2 to v3
- none

Change from v1 to v2
- Add Haibo Chen <haibo.chen@nxp.com>
- change cast to uintptr_t to fix below warning

| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202411052345.gyJaM3h4-lkp@intel.com/
All warnings (new ones prefixed by >>):

   In file included from drivers/iio/adc/vf610_adc.c:20:   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:21:
   In file included from include/linux/mm.h:2213:
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~>> drivers/iio/adc/vf610_adc.c:874:28: warning: cast to smaller integer type 'u32' (aka 'unsigned int') from 'const void *' [-Wvoid-pointer-to-int-cast]
     874 |         indio_dev->num_channels = (u32)device_get_match_data(dev);
         |
---
 drivers/iio/adc/vf610_adc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
index a6a0ada8a102f..36f6132bf5ba4 100644
--- a/drivers/iio/adc/vf610_adc.c
+++ b/drivers/iio/adc/vf610_adc.c
@@ -809,7 +809,8 @@ static const struct iio_info vf610_adc_iio_info = {
 };
 
 static const struct of_device_id vf610_adc_match[] = {
-	{ .compatible = "fsl,vf610-adc", },
+	{ .compatible = "fsl,imx6sx-adc", .data = (void *)4},
+	{ .compatible = "fsl,vf610-adc", .data = (void *)ARRAY_SIZE(vf610_adc_iio_channels)},
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, vf610_adc_match);
@@ -870,7 +871,7 @@ static int vf610_adc_probe(struct platform_device *pdev)
 	indio_dev->info = &vf610_adc_iio_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = vf610_adc_iio_channels;
-	indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
+	indio_dev->num_channels = (uintptr_t)device_get_match_data(dev);
 
 	vf610_adc_cfg_init(info);
 	vf610_adc_hw_init(info);
-- 
2.34.1

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Christophe JAILLET]

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@public.gmane.org>
> Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc@public.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@public.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?

>   
> -	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)

>   
>   	info->vref = devm_regulator_get(&pdev->dev, "vref");

With the change to devm_regulator_get_enable_read_voltage(), is it still 
needed?

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);
>   

...

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Frank Li]

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@public.gmane.org>
> > Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc@public.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@public.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);
>
> ...
>

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Christophe JAILLET]

Le 07/11/2024 à 20:49, Frank Li a écrit :
> 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-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
>>> Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
>>> ---

...

>>
>>>    	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.

Ok.

But why switch to devm_regulator_get_enable_read_voltage() then?
Shouldn't keeping regulator_get_voltage() be enough and simpler?

CJ

> 
>>
>> 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);
>>
>> ...
>>
> 
> 

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Frank Li]

On Fri, Nov 08, 2024 at 07:13:20AM +0100, Christophe JAILLET wrote:
> Le 07/11/2024 à 20:49, Frank Li a écrit :
> > 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-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
> > > > Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
> > > > ---
>
> ...
>
> > >
> > > >    	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.
>
> Ok.
>
> But why switch to devm_regulator_get_enable_read_voltage() then?
> Shouldn't keeping regulator_get_voltage() be enough and simpler?

Avoid goto err after devm_regulator_get_enable_read_voltage(), if use
regulator_enable(), it needs regulator_disable() in err handle branch after
it.

Frank

>
> CJ
>
> >
> > >
> > > 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);
> > >
> > > ...
> > >
> >
> >
>

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Jonathan Cameron]

On Fri, 8 Nov 2024 14:12:29 -0500
Frank Li <Frank.li@nxp.com> wrote:

> On Fri, Nov 08, 2024 at 07:13:20AM +0100, Christophe JAILLET wrote:
> > Le 07/11/2024 à 20:49, Frank Li a écrit :  
> > > 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-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
> > > > > Signed-off-by: Frank Li <Frank.Li-3arQi8VN3Tc-XMD5yJDbdMReXY1tMh2IBg@public.gmane.org>
> > > > > ---  
> >
> > ...
> >  
> > > >  
> > > > >    	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.  
> >
> > Ok.
> >
> > But why switch to devm_regulator_get_enable_read_voltage() then?
> > Shouldn't keeping regulator_get_voltage() be enough and simpler?  
> 
> Avoid goto err after devm_regulator_get_enable_read_voltage(), if use
> regulator_enable(), it needs regulator_disable() in err handle branch after
> it.

Don't get the same regulator twice - that works but is likely to be error
prone in the long run and is a bit too subtle.

This isn't an appropriate use of devm_regulator_get_enable_read_voltage()
Instead just use a local callback and
devm_add_action_or_reset() to disable the regulator in the devm tear down path.

Jonathan

> 
> Frank
> 
> >
> > CJ
> >  
> > >  
> > > >
> > > > 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);  
> > > >
> > > > ...
> > > >  
> > >
> > >  
> >  

Re: [PATCH v3 1/2] iio: adc: vf610_adc: use devm_* and dev_err_probe() to simple code

[Jonathan Cameron]

On Thu,  7 Nov 2024 14:18:40 -0500
Frank Li <Frank.Li@nxp.com> wrote:

> 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@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
One comment inline. 

> ---
> Change from v2 to v3
> - change vref_uv to int from u32 to fix below warning

That's not the nicest way to fix the issue. See below.

> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202411070633.NIrO7Ert-lkp@intel.com/
> 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);
>  
> -	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));
>  
>  	info->vref = devm_regulator_get(&pdev->dev, "vref");
>  	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;
whilst I've suggested not doing this in this fashion anyway so this code will probably
go away but in general prefer this sort of handling done as

	ret = devm_regulator_get_enable_read_voltage();
	if (ret < 0)
		return ret;

	info->vref_uv = ret;

so that we don't bounce a potential error code through a state variable and have
to change the type as you have done here.
>  
>  	device_property_read_u32_array(dev, "fsl,adck-max-frequency", info->max_adck_rate, 3);
>  
> @@ -879,52 +872,21 @@ static int vf610_adc_probe(struct platform_device *pdev)
>  	indio_dev->channels = vf610_adc_iio_channels;
>  	indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
>  
> -	ret = clk_prepare_enable(info->clk);
> -	if (ret) {
> -		dev_err(&pdev->dev,
> -			"Could not prepare or enable the clock.\n");
> -		goto error_adc_clk_enable;
> -	}
> -
>  	vf610_adc_cfg_init(info);
>  	vf610_adc_hw_init(info);
>  
> -	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
> -					NULL, &iio_triggered_buffer_setup_ops);
> -	if (ret < 0) {
> -		dev_err(&pdev->dev, "Couldn't initialise the buffer\n");
> -		goto error_iio_device_register;
> -	}
> +	ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, &iio_pollfunc_store_time,
> +					      NULL, &iio_triggered_buffer_setup_ops);
> +	if (ret < 0)
> +		return dev_err_probe(&pdev->dev, ret, "Couldn't initialise the buffer\n");
>  
>  	mutex_init(&info->lock);
>  
> -	ret = iio_device_register(indio_dev);
> -	if (ret) {
> -		dev_err(&pdev->dev, "Couldn't register the device.\n");
> -		goto error_adc_buffer_init;
> -	}
> +	ret = devm_iio_device_register(&pdev->dev, indio_dev);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Couldn't register the device.\n");
>  
>  	return 0;
> -
> -error_adc_buffer_init:
> -	iio_triggered_buffer_cleanup(indio_dev);
> -error_iio_device_register:
> -	clk_disable_unprepare(info->clk);
> -error_adc_clk_enable:
> -	regulator_disable(info->vref);
> -
> -	return ret;
> -}
> -
> -static void vf610_adc_remove(struct platform_device *pdev)
> -{
> -	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
> -	struct vf610_adc *info = iio_priv(indio_dev);
> -
> -	iio_device_unregister(indio_dev);
> -	iio_triggered_buffer_cleanup(indio_dev);
> -	regulator_disable(info->vref);
> -	clk_disable_unprepare(info->clk);
>  }
>  
>  static int vf610_adc_suspend(struct device *dev)
> @@ -972,7 +934,6 @@ static DEFINE_SIMPLE_DEV_PM_OPS(vf610_adc_pm_ops, vf610_adc_suspend,
>  
>  static struct platform_driver vf610_adc_driver = {
>  	.probe          = vf610_adc_probe,
> -	.remove         = vf610_adc_remove,
>  	.driver         = {
>  		.name   = DRIVER_NAME,
>  		.of_match_table = vf610_adc_match,

Re: [PATCH v3 2/2] iio: adc: vf610_adc: limit i.MX6SX's channel number to 4

[Jonathan Cameron]

On Thu,  7 Nov 2024 14:18:41 -0500
Frank Li <Frank.Li@nxp.com> wrote:

> i.MX6SX only has 4 ADC channels, so limit channel numbers to 4 for
> compatible string 'fsl,imx6sx-adc'.
> 
> Reviewed-by: Haibo Chen <haibo.chen@nxp.com>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

I'm pretty strongly against putting integers in the id match
data variables.  Instead use a much more easily extended structure
(which will have one element for now)

struct vf610_chip_info {
	u8 num_channels;
};

and then pointers to that structure in the tables.

The integer path regularly goes wrong (0 causes trouble with error handling)
and so I push back on people doing this in new code.

One other comment inline.

Jonathan

> ---
> compatible string 'fsl,imx6sx-adc' already document in
> Documentation/devicetree/bindings/iio/adc/fsl,vf610-adc.yaml
> 
> Change from v2 to v3
> - none
> 
> Change from v1 to v2
> - Add Haibo Chen <haibo.chen@nxp.com>
> - change cast to uintptr_t to fix below warning
> 
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202411052345.gyJaM3h4-lkp@intel.com/
> All warnings (new ones prefixed by >>):
> 
>    In file included from drivers/iio/adc/vf610_adc.c:20:   In file included from include/linux/regulator/consumer.h:35:
>    In file included from include/linux/suspend.h:5:
>    In file included from include/linux/swap.h:9:
>    In file included from include/linux/memcontrol.h:21:
>    In file included from include/linux/mm.h:2213:
>    include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
>      518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
>          |                               ~~~~~~~~~~~ ^ ~~~>> drivers/iio/adc/vf610_adc.c:874:28: warning: cast to smaller integer type 'u32' (aka 'unsigned int') from 'const void *' [-Wvoid-pointer-to-int-cast]
>      874 |         indio_dev->num_channels = (u32)device_get_match_data(dev);
>          |
> ---
>  drivers/iio/adc/vf610_adc.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/adc/vf610_adc.c b/drivers/iio/adc/vf610_adc.c
> index a6a0ada8a102f..36f6132bf5ba4 100644
> --- a/drivers/iio/adc/vf610_adc.c
> +++ b/drivers/iio/adc/vf610_adc.c
> @@ -809,7 +809,8 @@ static const struct iio_info vf610_adc_iio_info = {
>  };
>  
>  static const struct of_device_id vf610_adc_match[] = {
> -	{ .compatible = "fsl,vf610-adc", },
> +	{ .compatible = "fsl,imx6sx-adc", .data = (void *)4},
> +	{ .compatible = "fsl,vf610-adc", .data = (void *)ARRAY_SIZE(vf610_adc_iio_channels)},
>  	{ /* sentinel */ }
>  };
>  MODULE_DEVICE_TABLE(of, vf610_adc_match);
> @@ -870,7 +871,7 @@ static int vf610_adc_probe(struct platform_device *pdev)
>  	indio_dev->info = &vf610_adc_iio_info;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>  	indio_dev->channels = vf610_adc_iio_channels;
> -	indio_dev->num_channels = ARRAY_SIZE(vf610_adc_iio_channels);
> +	indio_dev->num_channels = (uintptr_t)device_get_match_data(dev);
That can in theory fail and return NULL. Which here would be interpreted
as 0 channels and probably cause trouble later.

>  
>  	vf610_adc_cfg_init(info);
>  	vf610_adc_hw_init(info);