Re: [PATCH] Input: pwm-beeper - Use devm functions

["Fabio.Estevam@freescale.com" <Fabio.Estevam@freescale.com>]

Hi Dmitry,

[Sorry for the top posting. Not able to access a proper email client at the moment]

I didn't understand the problem in using devm_pwm_get(). Could you please explain?

Thanks

________________________________________
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Sent: Thursday, February 19, 2015 3:12 PM
To: Estevam Fabio-R49496
Cc: linux-input@vger.kernel.org; lars@metafoo.de
Subject: Re: [PATCH]  Input: pwm-beeper - Use devm functions

Hi Fabio,

On Thu, Feb 19, 2015 at 09:26:02AM -0200, Fabio Estevam wrote:
> By using devm functions the code can be simplified a bit.
>
> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
> ---
>  drivers/input/misc/pwm-beeper.c | 18 +++++-------------
>  1 file changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> index a28ee70..c5ccaee 100644
> --- a/drivers/input/misc/pwm-beeper.c
> +++ b/drivers/input/misc/pwm-beeper.c
> @@ -72,11 +72,11 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>       struct pwm_beeper *beeper;
>       int error;
>
> -     beeper = kzalloc(sizeof(*beeper), GFP_KERNEL);
> +     beeper = devm_kzalloc(&pdev->dev, sizeof(*beeper), GFP_KERNEL);
>       if (!beeper)
>               return -ENOMEM;
>
> -     beeper->pwm = pwm_get(&pdev->dev, NULL);
> +     beeper->pwm = devm_pwm_get(&pdev->dev, NULL);
>       if (IS_ERR(beeper->pwm)) {
>               dev_dbg(&pdev->dev, "unable to request PWM, trying legacy API\n");
>               beeper->pwm = pwm_request(pwm_id, "pwm beeper");

This is not managed resource anymore, what will free it?

> @@ -85,14 +85,13 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>       if (IS_ERR(beeper->pwm)) {
>               error = PTR_ERR(beeper->pwm);
>               dev_err(&pdev->dev, "Failed to request pwm device: %d\n", error);
> -             goto err_free;
> +             return error;
>       }
>
> -     beeper->input = input_allocate_device();
> +     beeper->input = devm_input_allocate_device(&pdev->dev);
>       if (!beeper->input) {
>               dev_err(&pdev->dev, "Failed to allocate input device\n");
> -             error = -ENOMEM;
> -             goto err_pwm_free;
> +             return -ENOMEM;
>       }
>       beeper->input->dev.parent = &pdev->dev;
>
> @@ -122,10 +121,6 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>
>  err_input_free:
>       input_free_device(beeper->input);
> -err_pwm_free:
> -     pwm_free(beeper->pwm);
> -err_free:
> -     kfree(beeper);
>
>       return error;
>  }
> @@ -137,9 +132,6 @@ static int pwm_beeper_remove(struct platform_device *pdev)
>       input_unregister_device(beeper->input);
>
>       pwm_disable(beeper->pwm);

If you solve the issue above, then if you move pwm_disable() into new
pwm_beeper_close() then you can get rid of pwm_beeper_remove() altogether.

> -     pwm_free(beeper->pwm);
> -
> -     kfree(beeper);
>
>       return 0;
>  }
> --
> 1.9.1
>

Thanks.

--
Dmitry