Re: [PATCH v2 3/4] Input: adc-keys - Use dev_err_probe in probe function

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 15/12/2025 13:29:31+0100, Nicolas Frattaroli wrote:
> Rework the probe function, and functions called by the probe function,
> to use dev_err_probe for error logging.
> 
> While at it, also do some minor style cleanups, like not error logging
> on -ENOMEM and using ! instead of == 0.
> 
> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
>  drivers/input/keyboard/adc-keys.c | 53 ++++++++++++++++-----------------------
>  1 file changed, 21 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/input/keyboard/adc-keys.c b/drivers/input/keyboard/adc-keys.c
> index 62376f34f7d0..6f2ddcecea99 100644
> --- a/drivers/input/keyboard/adc-keys.c
> +++ b/drivers/input/keyboard/adc-keys.c
> @@ -74,10 +74,8 @@ static int adc_keys_load_keymap(struct device *dev, struct adc_keys_state *st)
>  	int i;
>  
>  	st->num_keys = device_get_child_node_count(dev);
> -	if (st->num_keys == 0) {
> -		dev_err(dev, "keymap is missing\n");
> -		return -EINVAL;
> -	}
> +	if (!st->num_keys)
> +		return dev_err_probe(dev, -EINVAL, "keymap is missing\n");
>  
>  	map = devm_kmalloc_array(dev, st->num_keys, sizeof(*map), GFP_KERNEL);
>  	if (!map)
> @@ -86,17 +84,16 @@ static int adc_keys_load_keymap(struct device *dev, struct adc_keys_state *st)
>  	i = 0;
>  	device_for_each_child_node_scoped(dev, child) {
>  		if (fwnode_property_read_u32(child, "press-threshold-microvolt",
> -					     &map[i].voltage)) {
> -			dev_err(dev, "Key with invalid or missing voltage\n");
> -			return -EINVAL;
> -		}
> +					     &map[i].voltage))
> +			return dev_err_probe(dev, -EINVAL,
> +					     "Key with invalid or missing voltage\n");
> +
>  		map[i].voltage /= 1000;
>  
>  		if (fwnode_property_read_u32(child, "linux,code",
> -					     &map[i].code)) {
> -			dev_err(dev, "Key with invalid or missing linux,code\n");
> -			return -EINVAL;
> -		}
> +					     &map[i].code))
> +			return dev_err_probe(dev, -EINVAL,
> +					     "Key with invalid or missing linux,code\n");
>  
>  		if (fwnode_property_read_u32(child, "linux,input-type",
>  					     &map[i].type))
> @@ -129,7 +126,8 @@ static int adc_keys_probe(struct platform_device *pdev)
>  
>  	st->channel = devm_iio_channel_get(dev, "buttons");
>  	if (IS_ERR(st->channel))
> -		return PTR_ERR(st->channel);
> +		return dev_err_probe(dev, PTR_ERR(st->channel),
> +				     "Could not get iio channel\n");
>  
>  	if (!st->channel->indio_dev)
>  		return -ENXIO;
> @@ -138,16 +136,13 @@ static int adc_keys_probe(struct platform_device *pdev)
>  	if (error < 0)
>  		return error;
>  
> -	if (type != IIO_VOLTAGE) {
> -		dev_err(dev, "Incompatible channel type %d\n", type);
> -		return -EINVAL;
> -	}
> +	if (type != IIO_VOLTAGE)
> +		return dev_err_probe(dev, -EINVAL, "Incompatible channel type %d\n", type);
>  
>  	if (device_property_read_u32(dev, "keyup-threshold-microvolt",
> -				     &st->keyup_voltage)) {
> -		dev_err(dev, "Invalid or missing keyup voltage\n");
> -		return -EINVAL;
> -	}
> +				     &st->keyup_voltage))
> +		return dev_err_probe(dev, -EINVAL, "Invalid or missing keyup voltage\n");
> +
>  	st->keyup_voltage /= 1000;
>  
>  	error = adc_keys_load_keymap(dev, st);
> @@ -155,10 +150,8 @@ static int adc_keys_probe(struct platform_device *pdev)
>  		return error;
>  
>  	input = devm_input_allocate_device(dev);
> -	if (!input) {
> -		dev_err(dev, "failed to allocate input device\n");
> +	if (!input)
>  		return -ENOMEM;
> -	}
>  
>  	input_set_drvdata(input, st);
>  
> @@ -178,19 +171,15 @@ static int adc_keys_probe(struct platform_device *pdev)
>  
>  
>  	error = input_setup_polling(input, adc_keys_poll);
> -	if (error) {
> -		dev_err(dev, "Unable to set up polling: %d\n", error);
> -		return error;
> -	}
> +	if (error)
> +		return dev_err_probe(dev, error, "Unable to set up polling\n");
>  
>  	if (!device_property_read_u32(dev, "poll-interval", &value))
>  		input_set_poll_interval(input, value);
>  
>  	error = input_register_device(input);
> -	if (error) {
> -		dev_err(dev, "Unable to register input device: %d\n", error);
> -		return error;
> -	}
> +	if (error)
> +		return dev_err_probe(dev, error, "Unable to register input device\n");
>  
>  	return 0;
>  }
> 
> -- 
> 2.52.0
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com