[PATCH -next v2 0/3] iio: adc: at91_adc: Cleanup with the helpers

[PATCH -next v2 0/3] iio: adc: at91_adc: Cleanup with the helpers

[Jinjie Ruan]

Commit 7ef9651e9792 ("clk: Provide new devm_clk helpers for prepared
and enabled clocks") provides a new helper function to prepare and
enable a clock which keeps prepared (or enabled) during the whole
lifetime of the driver.

Use devm_request_irq() to request the interrupt, so we can
avoid having to manually clean this up.

Use the dev_err_probe() helper to simplify error handling during probe.
This also handle scenario, when EDEFER is returned and useless
error is printed.

Changes in v2:
- Also use devm_request_irq() and dev_err_probe() to clean up the at91_adc.
- Split the at91_adc patch out to be a new patch set.

Jinjie Ruan (3):
  iio: adc: at91_adc: Use devm_clk_get_enabled() helper function
  iio: adc: at91_adc: Use devm_request_irq() helper function
  iio: adc: at91_adc: Simplify with dev_err_probe()

 drivers/iio/adc/at91_adc.c | 105 ++++++++++++-------------------------
 1 file changed, 34 insertions(+), 71 deletions(-)

-- 
2.34.1


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[PATCH -next v2 1/3] iio: adc: at91_adc: Use devm_clk_get_enabled() helper function

[Jinjie Ruan]

The devm_clk_get_enabled() helper:
    - calls devm_clk_get()
    - calls clk_prepare_enable() and registers what is needed in order to
      call clk_disable_unprepare() when needed, as a managed resource.

This simplifies the code.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/iio/adc/at91_adc.c | 38 ++++++++++----------------------------
 1 file changed, 10 insertions(+), 28 deletions(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index de6650f9c4b1..318e33ce22fb 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -1087,32 +1087,20 @@ static int at91_adc_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
+	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
 	if (IS_ERR(st->clk)) {
-		dev_err(&pdev->dev, "Failed to get the clock.\n");
-		ret = PTR_ERR(st->clk);
-		goto error_free_irq;
-	}
-
-	ret = clk_prepare_enable(st->clk);
-	if (ret) {
 		dev_err(&pdev->dev,
 			"Could not prepare or enable the clock.\n");
+		ret = PTR_ERR(st->clk);
 		goto error_free_irq;
 	}
 
-	st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
+	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
 	if (IS_ERR(st->adc_clk)) {
-		dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
-		ret = PTR_ERR(st->adc_clk);
-		goto error_disable_clk;
-	}
-
-	ret = clk_prepare_enable(st->adc_clk);
-	if (ret) {
 		dev_err(&pdev->dev,
 			"Could not prepare or enable the ADC clock.\n");
-		goto error_disable_clk;
+		ret = PTR_ERR(st->adc_clk);
+		goto error_free_irq;
 	}
 
 	/*
@@ -1132,7 +1120,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	if (!st->startup_time) {
 		dev_err(&pdev->dev, "No startup time available.\n");
 		ret = -EINVAL;
-		goto error_disable_adc_clk;
+		goto error_free_irq;
 	}
 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
 
@@ -1160,7 +1148,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	ret = at91_adc_channel_init(idev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
-		goto error_disable_adc_clk;
+		goto error_free_irq;
 	}
 
 	init_waitqueue_head(&st->wq_data_avail);
@@ -1175,19 +1163,19 @@ static int at91_adc_probe(struct platform_device *pdev)
 		ret = at91_adc_buffer_init(idev);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
-			goto error_disable_adc_clk;
+			goto error_free_irq;
 		}
 
 		ret = at91_adc_trigger_init(idev);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
 			at91_adc_buffer_remove(idev);
-			goto error_disable_adc_clk;
+			goto error_free_irq;
 		}
 	} else {
 		ret = at91_ts_register(idev, pdev);
 		if (ret)
-			goto error_disable_adc_clk;
+			goto error_free_irq;
 
 		at91_ts_hw_init(idev, adc_clk_khz);
 	}
@@ -1207,10 +1195,6 @@ static int at91_adc_probe(struct platform_device *pdev)
 	} else {
 		at91_ts_unregister(st);
 	}
-error_disable_adc_clk:
-	clk_disable_unprepare(st->adc_clk);
-error_disable_clk:
-	clk_disable_unprepare(st->clk);
 error_free_irq:
 	free_irq(st->irq, idev);
 	return ret;
@@ -1228,8 +1212,6 @@ static int at91_adc_remove(struct platform_device *pdev)
 	} else {
 		at91_ts_unregister(st);
 	}
-	clk_disable_unprepare(st->adc_clk);
-	clk_disable_unprepare(st->clk);
 	free_irq(st->irq, idev);
 
 	return 0;
-- 
2.34.1


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Re: [PATCH -next v2 1/3] iio: adc: at91_adc: Use devm_clk_get_enabled() helper function

[Jonathan Cameron]

On Sat, 26 Aug 2023 10:29:20 +0800
Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> The devm_clk_get_enabled() helper:
>     - calls devm_clk_get()
>     - calls clk_prepare_enable() and registers what is needed in order to
>       call clk_disable_unprepare() when needed, as a managed resource.
> 
> This simplifies the code.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>

Hi Jinjie,

Whilst it probably doesn't introduce a 'real' bug this patch does result
in a change of ordering in the remove path that means the irq is now freed
before the clks are disabled which is different from previously.
Two ways to avoid this.
- Do the conversion from patch 2 before this - taking last element out
  of remove and adding it to be the first devm managed cleanup is always
  safe.
- Squash patches 1 and 2

I'd prefer the first option.

Jonathan



> ---
>  drivers/iio/adc/at91_adc.c | 38 ++++++++++----------------------------
>  1 file changed, 10 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index de6650f9c4b1..318e33ce22fb 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -1087,32 +1087,20 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		return ret;
>  	}
>  
> -	st->clk = devm_clk_get(&pdev->dev, "adc_clk");
> +	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
>  	if (IS_ERR(st->clk)) {
> -		dev_err(&pdev->dev, "Failed to get the clock.\n");
> -		ret = PTR_ERR(st->clk);
> -		goto error_free_irq;
> -	}
> -
> -	ret = clk_prepare_enable(st->clk);
> -	if (ret) {
>  		dev_err(&pdev->dev,
>  			"Could not prepare or enable the clock.\n");
> +		ret = PTR_ERR(st->clk);
>  		goto error_free_irq;
>  	}
>  
> -	st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
> +	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
>  	if (IS_ERR(st->adc_clk)) {
> -		dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
> -		ret = PTR_ERR(st->adc_clk);
> -		goto error_disable_clk;
> -	}
> -
> -	ret = clk_prepare_enable(st->adc_clk);
> -	if (ret) {
>  		dev_err(&pdev->dev,
>  			"Could not prepare or enable the ADC clock.\n");
> -		goto error_disable_clk;
> +		ret = PTR_ERR(st->adc_clk);
> +		goto error_free_irq;
>  	}
>  
>  	/*
> @@ -1132,7 +1120,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	if (!st->startup_time) {
>  		dev_err(&pdev->dev, "No startup time available.\n");
>  		ret = -EINVAL;
> -		goto error_disable_adc_clk;
> +		goto error_free_irq;
>  	}
>  	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
>  
> @@ -1160,7 +1148,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	ret = at91_adc_channel_init(idev);
>  	if (ret < 0) {
>  		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
> -		goto error_disable_adc_clk;
> +		goto error_free_irq;
>  	}
>  
>  	init_waitqueue_head(&st->wq_data_avail);
> @@ -1175,19 +1163,19 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		ret = at91_adc_buffer_init(idev);
>  		if (ret < 0) {
>  			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> -			goto error_disable_adc_clk;
> +			goto error_free_irq;
>  		}
>  
>  		ret = at91_adc_trigger_init(idev);
>  		if (ret < 0) {
>  			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
>  			at91_adc_buffer_remove(idev);
> -			goto error_disable_adc_clk;
> +			goto error_free_irq;
>  		}
>  	} else {
>  		ret = at91_ts_register(idev, pdev);
>  		if (ret)
> -			goto error_disable_adc_clk;
> +			goto error_free_irq;
>  
>  		at91_ts_hw_init(idev, adc_clk_khz);
>  	}
> @@ -1207,10 +1195,6 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	} else {
>  		at91_ts_unregister(st);
>  	}
> -error_disable_adc_clk:
> -	clk_disable_unprepare(st->adc_clk);
> -error_disable_clk:
> -	clk_disable_unprepare(st->clk);
>  error_free_irq:
>  	free_irq(st->irq, idev);
>  	return ret;
> @@ -1228,8 +1212,6 @@ static int at91_adc_remove(struct platform_device *pdev)
>  	} else {
>  		at91_ts_unregister(st);
>  	}
> -	clk_disable_unprepare(st->adc_clk);
> -	clk_disable_unprepare(st->clk);
>  	free_irq(st->irq, idev);
>  
>  	return 0;


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[PATCH -next v2 2/3] iio: adc: at91_adc: Use devm_request_irq() helper function

[Jinjie Ruan]

Use devm_request_irq() to request the interrupt, so we can
avoid having to manually clean this up.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/iio/adc/at91_adc.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 318e33ce22fb..2ac1b64f0fb7 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -1077,11 +1077,13 @@ static int at91_adc_probe(struct platform_device *pdev)
 	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
 
 	if (st->caps->has_tsmr)
-		ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
-				  pdev->dev.driver->name, idev);
+		ret = devm_request_irq(&pdev->dev, st->irq,
+				       at91_adc_9x5_interrupt, 0,
+				       pdev->dev.driver->name, idev);
 	else
-		ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
-				  pdev->dev.driver->name, idev);
+		ret = devm_request_irq(&pdev->dev, st->irq,
+				       at91_adc_rl_interrupt, 0,
+				       pdev->dev.driver->name, idev);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
 		return ret;
@@ -1092,7 +1094,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev,
 			"Could not prepare or enable the clock.\n");
 		ret = PTR_ERR(st->clk);
-		goto error_free_irq;
+		return ret;
 	}
 
 	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
@@ -1100,7 +1102,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev,
 			"Could not prepare or enable the ADC clock.\n");
 		ret = PTR_ERR(st->adc_clk);
-		goto error_free_irq;
+		return ret;
 	}
 
 	/*
@@ -1119,8 +1121,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	if (!st->startup_time) {
 		dev_err(&pdev->dev, "No startup time available.\n");
-		ret = -EINVAL;
-		goto error_free_irq;
+		return -EINVAL;
 	}
 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
 
@@ -1148,7 +1149,7 @@ static int at91_adc_probe(struct platform_device *pdev)
 	ret = at91_adc_channel_init(idev);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
-		goto error_free_irq;
+		return ret;
 	}
 
 	init_waitqueue_head(&st->wq_data_avail);
@@ -1163,19 +1164,19 @@ static int at91_adc_probe(struct platform_device *pdev)
 		ret = at91_adc_buffer_init(idev);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
-			goto error_free_irq;
+			return ret;
 		}
 
 		ret = at91_adc_trigger_init(idev);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
 			at91_adc_buffer_remove(idev);
-			goto error_free_irq;
+			return ret;
 		}
 	} else {
 		ret = at91_ts_register(idev, pdev);
 		if (ret)
-			goto error_free_irq;
+			return ret;
 
 		at91_ts_hw_init(idev, adc_clk_khz);
 	}
@@ -1195,8 +1196,6 @@ static int at91_adc_probe(struct platform_device *pdev)
 	} else {
 		at91_ts_unregister(st);
 	}
-error_free_irq:
-	free_irq(st->irq, idev);
 	return ret;
 }
 
@@ -1212,7 +1211,6 @@ static int at91_adc_remove(struct platform_device *pdev)
 	} else {
 		at91_ts_unregister(st);
 	}
-	free_irq(st->irq, idev);
 
 	return 0;
 }
-- 
2.34.1


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Re: [PATCH -next v2 2/3] iio: adc: at91_adc: Use devm_request_irq() helper function

[Jonathan Cameron]

On Sat, 26 Aug 2023 10:29:21 +0800
Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> Use devm_request_irq() to request the interrupt, so we can
> avoid having to manually clean this up.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
> ---
>  drivers/iio/adc/at91_adc.c | 28 +++++++++++++---------------
>  1 file changed, 13 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 318e33ce22fb..2ac1b64f0fb7 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -1077,11 +1077,13 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
>  
>  	if (st->caps->has_tsmr)
> -		ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
> -				  pdev->dev.driver->name, idev);
> +		ret = devm_request_irq(&pdev->dev, st->irq,
> +				       at91_adc_9x5_interrupt, 0,
> +				       pdev->dev.driver->name, idev);
>  	else
> -		ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
> -				  pdev->dev.driver->name, idev);
> +		ret = devm_request_irq(&pdev->dev, st->irq,
> +				       at91_adc_rl_interrupt, 0,
> +				       pdev->dev.driver->name, idev);
>  	if (ret) {
>  		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
>  		return ret;
> @@ -1092,7 +1094,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev,
>  			"Could not prepare or enable the clock.\n");
>  		ret = PTR_ERR(st->clk);
> -		goto error_free_irq;
> +		return ret;
Whilst they go away in the next patch, this does look odd as you can clearly just
do
		return PTR_ERR(st->clk);

In the interests of easy step wise patch review, I'd prefer that you made that
change in this patch in all the places this pattern occurs.

>  	}
>  
>  	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
> @@ -1100,7 +1102,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		dev_err(&pdev->dev,
>  			"Could not prepare or enable the ADC clock.\n");
>  		ret = PTR_ERR(st->adc_clk);
> -		goto error_free_irq;
> +		return ret;
>  	}
>  
>  	/*
> @@ -1119,8 +1121,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  
>  	if (!st->startup_time) {
>  		dev_err(&pdev->dev, "No startup time available.\n");
> -		ret = -EINVAL;
> -		goto error_free_irq;
> +		return -EINVAL;
>  	}
>  	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
>  
> @@ -1148,7 +1149,7 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	ret = at91_adc_channel_init(idev);
>  	if (ret < 0) {
>  		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
> -		goto error_free_irq;
> +		return ret;
>  	}
>  
>  	init_waitqueue_head(&st->wq_data_avail);
> @@ -1163,19 +1164,19 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		ret = at91_adc_buffer_init(idev);
>  		if (ret < 0) {
>  			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> -			goto error_free_irq;
> +			return ret;
>  		}
>  
>  		ret = at91_adc_trigger_init(idev);
>  		if (ret < 0) {
>  			dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
>  			at91_adc_buffer_remove(idev);
> -			goto error_free_irq;
> +			return ret;
>  		}
>  	} else {
>  		ret = at91_ts_register(idev, pdev);
>  		if (ret)
> -			goto error_free_irq;
> +			return ret;
>  
>  		at91_ts_hw_init(idev, adc_clk_khz);
>  	}
> @@ -1195,8 +1196,6 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	} else {
>  		at91_ts_unregister(st);
>  	}
> -error_free_irq:
> -	free_irq(st->irq, idev);
>  	return ret;
>  }
>  
> @@ -1212,7 +1211,6 @@ static int at91_adc_remove(struct platform_device *pdev)
>  	} else {
>  		at91_ts_unregister(st);
>  	}
> -	free_irq(st->irq, idev);
>  
>  	return 0;
>  }


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[PATCH -next v2 3/3] iio: adc: at91_adc: Simplify with dev_err_probe()

[Jinjie Ruan]

Use the dev_err_probe() helper to simplify error handling during probe.
This also handle scenario, when EDEFER is returned and useless error
is printed.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
---
 drivers/iio/adc/at91_adc.c | 65 ++++++++++++++------------------------
 1 file changed, 24 insertions(+), 41 deletions(-)

diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 2ac1b64f0fb7..a49f7021c73f 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -1013,28 +1013,25 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
 
-	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
-		dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
-		return -EINVAL;
-	}
+	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop))
+		return dev_err_probe(&idev->dev, -EINVAL,
+				     "Missing adc-channels-used property in the DT.\n");
 	st->channels_mask = prop;
 
 	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
 
-	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
-		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
-		return -EINVAL;
-	}
+	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop))
+		return dev_err_probe(&idev->dev, -EINVAL,
+				     "Missing adc-startup-time property in the DT.\n");
 	st->startup_time = prop;
 
 	prop = 0;
 	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
 	st->sample_hold_time = prop;
 
-	if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
-		dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
-		return -EINVAL;
-	}
+	if (of_property_read_u32(node, "atmel,adc-vref", &prop))
+		return dev_err_probe(&idev->dev, -EINVAL,
+				     "Missing adc-vref property in the DT.\n");
 	st->vref_mv = prop;
 
 	st->res = st->caps->high_res_bits;
@@ -1069,7 +1066,6 @@ static int at91_adc_probe(struct platform_device *pdev)
 	if (IS_ERR(st->reg_base))
 		return PTR_ERR(st->reg_base);
 
-
 	/*
 	 * Disable all IRQs before setting up the handler
 	 */
@@ -1084,26 +1080,18 @@ static int at91_adc_probe(struct platform_device *pdev)
 		ret = devm_request_irq(&pdev->dev, st->irq,
 				       at91_adc_rl_interrupt, 0,
 				       pdev->dev.driver->name, idev);
-	if (ret) {
-		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
-		return ret;
-	}
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret, "Failed to allocate IRQ.\n");
 
 	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
-	if (IS_ERR(st->clk)) {
-		dev_err(&pdev->dev,
-			"Could not prepare or enable the clock.\n");
-		ret = PTR_ERR(st->clk);
-		return ret;
-	}
+	if (IS_ERR(st->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(st->clk),
+				     "Could not prepare or enable the clock.\n");
 
 	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
-	if (IS_ERR(st->adc_clk)) {
-		dev_err(&pdev->dev,
-			"Could not prepare or enable the ADC clock.\n");
-		ret = PTR_ERR(st->adc_clk);
-		return ret;
-	}
+	if (IS_ERR(st->adc_clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(st->adc_clk),
+				     "Could not prepare or enable the ADC clock.\n");
 
 	/*
 	 * Prescaler rate computation using the formula from the Atmel's
@@ -1119,10 +1107,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	prsc = (mstrclk / (2 * adc_clk)) - 1;
 
-	if (!st->startup_time) {
-		dev_err(&pdev->dev, "No startup time available.\n");
-		return -EINVAL;
-	}
+	if (!st->startup_time)
+		return dev_err_probe(&pdev->dev, -EINVAL, "No startup time available.\n");
 	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
 
 	/*
@@ -1147,10 +1133,8 @@ static int at91_adc_probe(struct platform_device *pdev)
 
 	/* Setup the ADC channels available on the board */
 	ret = at91_adc_channel_init(idev);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
-		return ret;
-	}
+	if (ret < 0)
+		return dev_err_probe(&pdev->dev, ret, "Couldn't initialize the channels.\n");
 
 	init_waitqueue_head(&st->wq_data_avail);
 	mutex_init(&st->lock);
@@ -1162,10 +1146,9 @@ static int at91_adc_probe(struct platform_device *pdev)
 	 */
 	if (!st->touchscreen_type) {
 		ret = at91_adc_buffer_init(idev);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
-			return ret;
-		}
+		if (ret < 0)
+			return dev_err_probe(&pdev->dev, ret,
+					     "Couldn't initialize the buffer.\n");
 
 		ret = at91_adc_trigger_init(idev);
 		if (ret < 0) {
-- 
2.34.1


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Re: [PATCH -next v2 3/3] iio: adc: at91_adc: Simplify with dev_err_probe()

[Jonathan Cameron]

On Sat, 26 Aug 2023 10:29:22 +0800
Jinjie Ruan <ruanjinjie@huawei.com> wrote:

> Use the dev_err_probe() helper to simplify error handling during probe.
> This also handle scenario, when EDEFER is returned and useless error
> is printed.
> 
> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
As I've asked for other changes so there will probably be another version
anyway - a few trivial comments inline.  Mostly you've hit the right balance
on line breaks, but there are a few more I'd like to see with the aim of
not going any longer than 80 chars than is necessary.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/at91_adc.c | 65 ++++++++++++++------------------------
>  1 file changed, 24 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 2ac1b64f0fb7..a49f7021c73f 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -1013,28 +1013,25 @@ static int at91_adc_probe(struct platform_device *pdev)
>  
>  	st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
>  
> -	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
> -		dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
> -		return -EINVAL;
> -	}
> +	if (of_property_read_u32(node, "atmel,adc-channels-used", &prop))
> +		return dev_err_probe(&idev->dev, -EINVAL,
> +				     "Missing adc-channels-used property in the DT.\n");
>  	st->channels_mask = prop;
>  
>  	st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
>  
> -	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
> -		dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
> -		return -EINVAL;
> -	}
> +	if (of_property_read_u32(node, "atmel,adc-startup-time", &prop))
> +		return dev_err_probe(&idev->dev, -EINVAL,
> +				     "Missing adc-startup-time property in the DT.\n");
>  	st->startup_time = prop;
>  
>  	prop = 0;
>  	of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
>  	st->sample_hold_time = prop;
>  
> -	if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
> -		dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
> -		return -EINVAL;
> -	}
> +	if (of_property_read_u32(node, "atmel,adc-vref", &prop))
> +		return dev_err_probe(&idev->dev, -EINVAL,
> +				     "Missing adc-vref property in the DT.\n");
>  	st->vref_mv = prop;
>  
>  	st->res = st->caps->high_res_bits;
> @@ -1069,7 +1066,6 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	if (IS_ERR(st->reg_base))
>  		return PTR_ERR(st->reg_base);
>  
> -
>  	/*
>  	 * Disable all IRQs before setting up the handler
>  	 */
> @@ -1084,26 +1080,18 @@ static int at91_adc_probe(struct platform_device *pdev)
>  		ret = devm_request_irq(&pdev->dev, st->irq,
>  				       at91_adc_rl_interrupt, 0,
>  				       pdev->dev.driver->name, idev);
> -	if (ret) {
> -		dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
> -		return ret;
> -	}
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret, "Failed to allocate IRQ.\n");
>  
>  	st->clk = devm_clk_get_enabled(&pdev->dev, "adc_clk");
> -	if (IS_ERR(st->clk)) {
> -		dev_err(&pdev->dev,
> -			"Could not prepare or enable the clock.\n");
> -		ret = PTR_ERR(st->clk);
> -		return ret;
> -	}
> +	if (IS_ERR(st->clk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(st->clk),
> +				     "Could not prepare or enable the clock.\n");
>  
>  	st->adc_clk = devm_clk_get_enabled(&pdev->dev, "adc_op_clk");
> -	if (IS_ERR(st->adc_clk)) {
> -		dev_err(&pdev->dev,
> -			"Could not prepare or enable the ADC clock.\n");
> -		ret = PTR_ERR(st->adc_clk);
> -		return ret;
> -	}
> +	if (IS_ERR(st->adc_clk))
> +		return dev_err_probe(&pdev->dev, PTR_ERR(st->adc_clk),
> +				     "Could not prepare or enable the ADC clock.\n");
>  
>  	/*
>  	 * Prescaler rate computation using the formula from the Atmel's
> @@ -1119,10 +1107,8 @@ static int at91_adc_probe(struct platform_device *pdev)
>  
>  	prsc = (mstrclk / (2 * adc_clk)) - 1;
>  
> -	if (!st->startup_time) {
> -		dev_err(&pdev->dev, "No startup time available.\n");
> -		return -EINVAL;
> -	}
> +	if (!st->startup_time)
> +		return dev_err_probe(&pdev->dev, -EINVAL, "No startup time available.\n");

Add a line break before the "

>  	ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
>  
>  	/*
> @@ -1147,10 +1133,8 @@ static int at91_adc_probe(struct platform_device *pdev)
>  
>  	/* Setup the ADC channels available on the board */
>  	ret = at91_adc_channel_init(idev);
> -	if (ret < 0) {
> -		dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
> -		return ret;
> -	}
> +	if (ret < 0)
> +		return dev_err_probe(&pdev->dev, ret, "Couldn't initialize the channels.\n");

Line break before "

>  
>  	init_waitqueue_head(&st->wq_data_avail);
>  	mutex_init(&st->lock);
> @@ -1162,10 +1146,9 @@ static int at91_adc_probe(struct platform_device *pdev)
>  	 */
>  	if (!st->touchscreen_type) {
>  		ret = at91_adc_buffer_init(idev);
> -		if (ret < 0) {
> -			dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
> -			return ret;
> -		}
> +		if (ret < 0)
> +			return dev_err_probe(&pdev->dev, ret,
> +					     "Couldn't initialize the buffer.\n");
>  
>  		ret = at91_adc_trigger_init(idev);
>  		if (ret < 0) {


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