Re: [PATCH v2 2/4] input: keyboard: tegra: use devm_* for resource allocation

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Laxman,

On Sat, Jan 05, 2013 at 01:15:08PM +0530, Laxman Dewangan wrote:
> Use devm_* for memory, clock, input device allocation. This reduces
> code for freeing these resources.
> 
> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
> ---
> Changes from V1:
> None
> 
>  drivers/input/keyboard/tegra-kbc.c |   93 +++++++++++-------------------------
>  1 files changed, 28 insertions(+), 65 deletions(-)
> 
> diff --git a/drivers/input/keyboard/tegra-kbc.c b/drivers/input/keyboard/tegra-kbc.c
> index f1d3ba0..c036425 100644
> --- a/drivers/input/keyboard/tegra-kbc.c
> +++ b/drivers/input/keyboard/tegra-kbc.c
> @@ -618,7 +618,7 @@ static struct tegra_kbc_platform_data *tegra_kbc_dt_parse_pdata(
>  	if (!np)
>  		return NULL;
>  
> -	pdata = kzalloc(sizeof(*pdata), GFP_KERNEL);
> +	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
>  	if (!pdata)
>  		return NULL;
>  
> @@ -700,33 +700,36 @@ static int tegra_kbc_probe(struct platform_device *pdev)
>  	if (!pdata)
>  		pdata = tegra_kbc_dt_parse_pdata(pdev);
>  
> -	if (!pdata)
> +	if (!pdata) {
> +		dev_err(&pdev->dev, "Platform data missing\n");
>  		return -EINVAL;
> -
> -	if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows)) {
> -		err = -EINVAL;
> -		goto err_free_pdata;
>  	}
>  
> +	if (!tegra_kbc_check_pin_cfg(pdata, &pdev->dev, &num_rows))
> +		return -EINVAL;
> +
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>  	if (!res) {
>  		dev_err(&pdev->dev, "failed to get I/O memory\n");
> -		err = -ENXIO;
> -		goto err_free_pdata;
> +		return -ENXIO;
>  	}
>  
>  	irq = platform_get_irq(pdev, 0);
>  	if (irq < 0) {
>  		dev_err(&pdev->dev, "failed to get keyboard IRQ\n");
> -		err = -ENXIO;
> -		goto err_free_pdata;
> +		return -ENXIO;
> +	}
> +
> +	kbc = devm_kzalloc(&pdev->dev, sizeof(*kbc), GFP_KERNEL);
> +	if (!kbc) {
> +		dev_err(&pdev->dev, "failed to alloc memory for kbc\n");
> +		return -ENOMEM;
>  	}
>  
> -	kbc = kzalloc(sizeof(*kbc), GFP_KERNEL);
> -	input_dev = input_allocate_device();
> -	if (!kbc || !input_dev) {
> -		err = -ENOMEM;
> -		goto err_free_mem;
> +	input_dev = devm_input_allocate_device(&pdev->dev);
> +	if (!input_dev) {
> +		dev_err(&pdev->dev, "failed to allocate input device\n");
> +		return -ENOMEM;
>  	}
>  
>  	kbc->pdata = pdata;
> @@ -735,25 +738,16 @@ static int tegra_kbc_probe(struct platform_device *pdev)
>  	spin_lock_init(&kbc->lock);
>  	setup_timer(&kbc->timer, tegra_kbc_keypress_timer, (unsigned long)kbc);
>  
> -	res = request_mem_region(res->start, resource_size(res), pdev->name);
> -	if (!res) {
> -		dev_err(&pdev->dev, "failed to request I/O memory\n");
> -		err = -EBUSY;
> -		goto err_free_mem;
> -	}
> -
> -	kbc->mmio = ioremap(res->start, resource_size(res));
> +	kbc->mmio = devm_request_and_ioremap(&pdev->dev, res);
>  	if (!kbc->mmio) {
> -		dev_err(&pdev->dev, "failed to remap I/O memory\n");
> -		err = -ENXIO;
> -		goto err_free_mem_region;
> +		dev_err(&pdev->dev, "Cannot request memregion/iomap address\n");
> +		return -EADDRNOTAVAIL;

Erm, no, -EBUSY please.

>  	}
>  
> -	kbc->clk = clk_get(&pdev->dev, NULL);
> +	kbc->clk = devm_clk_get(&pdev->dev, NULL);
>  	if (IS_ERR(kbc->clk)) {
>  		dev_err(&pdev->dev, "failed to get keyboard clock\n");
> -		err = PTR_ERR(kbc->clk);
> -		goto err_iounmap;
> +		return PTR_ERR(kbc->clk);
>  	}
>  
>  	/*
> @@ -778,9 +772,9 @@ static int tegra_kbc_probe(struct platform_device *pdev)
>  	input_dev->close = tegra_kbc_close;
>  
>  	err = tegra_kbd_setup_keymap(kbc);
> -	if (err) {
> +	if (err < 0) {

Why is this change? As far as I can see tegra_kbd_setup_keymap() never
returns positive values.

>  		dev_err(&pdev->dev, "failed to setup keymap\n");
> -		goto err_put_clk;
> +		return err;
>  	}
>  
>  	__set_bit(EV_REP, input_dev->evbit);
> @@ -790,15 +784,15 @@ static int tegra_kbc_probe(struct platform_device *pdev)
>  
>  	err = request_irq(kbc->irq, tegra_kbc_isr,
>  			  IRQF_NO_SUSPEND | IRQF_TRIGGER_HIGH, pdev->name, kbc);
> -	if (err) {
> +	if (err < 0) {

Neither request_irq(). BTW, why not devm_request_irq?

>  		dev_err(&pdev->dev, "failed to request keyboard IRQ\n");
> -		goto err_put_clk;
> +		return err;
>  	}
>  
>  	disable_irq(kbc->irq);
>  
>  	err = input_register_device(kbc->idev);
> -	if (err) {
> +	if (err < 0) {

Again, input_register_device() returns 0 on success.

>  		dev_err(&pdev->dev, "failed to register input device\n");
>  		goto err_free_irq;
>  	}
> @@ -810,46 +804,15 @@ static int tegra_kbc_probe(struct platform_device *pdev)
>  
>  err_free_irq:
>  	free_irq(kbc->irq, pdev);
> -err_put_clk:
> -	clk_put(kbc->clk);
> -err_iounmap:
> -	iounmap(kbc->mmio);
> -err_free_mem_region:
> -	release_mem_region(res->start, resource_size(res));
> -err_free_mem:
> -	input_free_device(input_dev);
> -	kfree(kbc);
> -err_free_pdata:
> -	if (!pdev->dev.platform_data)
> -		kfree(pdata);
> -
>  	return err;
>  }
>  
>  static int tegra_kbc_remove(struct platform_device *pdev)
>  {
>  	struct tegra_kbc *kbc = platform_get_drvdata(pdev);
> -	struct resource *res;
> -
> -	platform_set_drvdata(pdev, NULL);
>  
>  	free_irq(kbc->irq, pdev);
> -	clk_put(kbc->clk);
> -
>  	input_unregister_device(kbc->idev);

You do not need to call input_unregister_device for managed input
devices, and if you switch request_irq to managed variant you can remove 
tegra_kbc_remove() altogether.

> -	iounmap(kbc->mmio);
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	release_mem_region(res->start, resource_size(res));
> -
> -	/*
> -	 * If we do not have platform data attached to the device we
> -	 * allocated it ourselves and thus need to free it.
> -	 */
> -	if (!pdev->dev.platform_data)
> -		kfree(kbc->pdata);
> -
> -	kfree(kbc);
> -
>  	return 0;
>  }
>  
> -- 
> 1.7.1.1
> 

Thanks.

-- 
Dmitry