Subject: [PATCH v2 1/3] Input: rotary-encoder - make use of devm_* to simplify .probe and .remove

From: [email-masked] (Daniel Mack)
Date: Tue, 2 Feb 2016 12:56:24 +0100

On 02/02/2016 11:24 AM, Uwe Kleine-K?nig wrote:
> For all operations called in .probe there are devm_* variants.
> (input_register_device is clever enough to be devm aware on its own.)
> This allows to get rid of the error unwind code paths in .probe and the
> complete .remove function.

While at it, could you also convert this over to the gpiod_* API?

Thanks,
Daniel

> 
> Signed-off-by: Uwe Kleine-K?nig <[email-masked]>
> ---
>  drivers/input/misc/rotary_encoder.c | 74 +++++++++++--------------------------
>  1 file changed, 22 insertions(+), 52 deletions(-)
> 
> diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
> index 8aee71986430..386bdb5314e6 100644
> --- a/drivers/input/misc/rotary_encoder.c
> +++ b/drivers/input/misc/rotary_encoder.c
> @@ -211,8 +211,8 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
>  	if (!of_id || !np)
>  		return NULL;
>  
> -	pdata = kzalloc(sizeof(struct rotary_encoder_platform_data),
> -			GFP_KERNEL);
> +	pdata = devm_kzalloc(dev, sizeof(struct rotary_encoder_platform_data),
> +			     GFP_KERNEL);
>  	if (!pdata)
>  		return ERR_PTR(-ENOMEM);
>  
> @@ -277,11 +277,11 @@ static int rotary_encoder_probe(struct platform_device *pdev)
>  		}
>  	}
>  
> -	encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL);
> -	input = input_allocate_device();
> +	encoder = devm_kzalloc(dev, sizeof(struct rotary_encoder), GFP_KERNEL);
> +	input = devm_input_allocate_device(&pdev->dev);
>  	if (!encoder || !input) {
> -		err = -ENOMEM;
> -		goto exit_free_mem;
> +		dev_err(dev, "unable to allocate memory\n");
> +		return -ENOMEM;
>  	}
>  
>  	encoder->input = input;
> @@ -301,16 +301,18 @@ static int rotary_encoder_probe(struct platform_device *pdev)
>  	}
>  
>  	/* request the GPIOs */
> -	err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev));
> +	err = devm_gpio_request_one(dev, pdata->gpio_a,
> +				    GPIOF_IN, dev_name(dev));
>  	if (err) {
>  		dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a);
> -		goto exit_free_mem;
> +		return err;
>  	}
>  
> -	err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev));
> +	err = devm_gpio_request_one(dev, pdata->gpio_b,
> +				    GPIOF_IN, dev_name(dev));
>  	if (err) {
>  		dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_b);
> -		goto exit_free_gpio_a;
> +		return err;
>  	}
>  
>  	encoder->irq_a = gpio_to_irq(pdata->gpio_a);
> @@ -331,30 +333,29 @@ static int rotary_encoder_probe(struct platform_device *pdev)
>  	default:
>  		dev_err(dev, "'%d' is not a valid steps-per-period value\n",
>  			pdata->steps_per_period);
> -		err = -EINVAL;
> -		goto exit_free_gpio_b;
> +		return -EINVAL;
>  	}
>  
> -	err = request_irq(encoder->irq_a, handler,
> -			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> -			  DRV_NAME, encoder);
> +	err = devm_request_irq(dev, encoder->irq_a, handler,
> +			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> +			       DRV_NAME, encoder);
>  	if (err) {
>  		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a);
> -		goto exit_free_gpio_b;
> +		return err;
>  	}
>  
> -	err = request_irq(encoder->irq_b, handler,
> -			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> -			  DRV_NAME, encoder);
> +	err = devm_request_irq(dev, encoder->irq_b, handler,
> +			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
> +			       DRV_NAME, encoder);
>  	if (err) {
>  		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b);
> -		goto exit_free_irq_a;
> +		return err;
>  	}
>  
>  	err = input_register_device(input);
>  	if (err) {
>  		dev_err(dev, "failed to register input device\n");
> -		goto exit_free_irq_b;
> +		return err;
>  	}
>  
>  	device_init_wakeup(&pdev->dev, pdata->wakeup_source);
> @@ -362,42 +363,11 @@ static int rotary_encoder_probe(struct platform_device *pdev)
>  	platform_set_drvdata(pdev, encoder);
>  
>  	return 0;
> -
> -exit_free_irq_b:
> -	free_irq(encoder->irq_b, encoder);
> -exit_free_irq_a:
> -	free_irq(encoder->irq_a, encoder);
> -exit_free_gpio_b:
> -	gpio_free(pdata->gpio_b);
> -exit_free_gpio_a:
> -	gpio_free(pdata->gpio_a);
> -exit_free_mem:
> -	input_free_device(input);
> -	kfree(encoder);
> -	if (!dev_get_platdata(&pdev->dev))
> -		kfree(pdata);
> -
> -	return err;
>  }
>  
>  static int rotary_encoder_remove(struct platform_device *pdev)
>  {
> -	struct rotary_encoder *encoder = platform_get_drvdata(pdev);
> -	const struct rotary_encoder_platform_data *pdata = encoder->pdata;
> -
>  	device_init_wakeup(&pdev->dev, false);
> -
> -	free_irq(encoder->irq_a, encoder);
> -	free_irq(encoder->irq_b, encoder);
> -	gpio_free(pdata->gpio_a);
> -	gpio_free(pdata->gpio_b);
> -
> -	input_unregister_device(encoder->input);
> -	kfree(encoder);
> -
> -	if (!dev_get_platdata(&pdev->dev))
> -		kfree(pdata);
> -
>  	return 0;
>  }
>  
>