Re: [PATCH] Input: opencores-kbd: Switch to using managed resources

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

On Tue, Oct 07, 2014 at 03:33:22PM +0200, Tobias Klauser wrote:
> On 2014-10-07 at 13:31:41 +0200, Pramod Gurav <pramod.gurav@smartplayin.com> wrote:
> > This change switch to managed resources to simplifies error handling
> > and module unloading and does away with platform_driver remove function.
> > 
> > Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
> > Cc: linux-input@vger.kernel.org
> > Signed-off-by: Pramod Gurav <pramod.gurav@smartplayin.com>
> > ---
> >  drivers/input/keyboard/opencores-kbd.c |   54 ++++++++------------------------
> >  1 file changed, 13 insertions(+), 41 deletions(-)
> > 
> > diff --git a/drivers/input/keyboard/opencores-kbd.c b/drivers/input/keyboard/opencores-kbd.c
> > index 7b9b441..ecacb87 100644
> > --- a/drivers/input/keyboard/opencores-kbd.c
> > +++ b/drivers/input/keyboard/opencores-kbd.c
> > @@ -56,27 +56,27 @@ static int opencores_kbd_probe(struct platform_device *pdev)
> >  		return -EINVAL;
> >  	}
> >  
> > -	opencores_kbd = kzalloc(sizeof(*opencores_kbd), GFP_KERNEL);
> > -	input = input_allocate_device();
> > +	opencores_kbd = devm_kzalloc(&pdev->dev, sizeof(*opencores_kbd),
> > +				     GFP_KERNEL);
> > +	input = devm_input_allocate_device(&pdev->dev);
> >  	if (!opencores_kbd || !input) {
> >  		dev_err(&pdev->dev, "failed to allocate device structures\n");
> > -		error = -ENOMEM;
> > -		goto err_free_mem;
> > +		return -ENOMEM;
> >  	}
> >  
> >  	opencores_kbd->addr_res = res;
> > -	res = request_mem_region(res->start, resource_size(res), pdev->name);
> > +	res = devm_request_mem_region(&pdev->dev, res->start,
> > +				      resource_size(res), pdev->name);
> >  	if (!res) {
> >  		dev_err(&pdev->dev, "failed to request I/O memory\n");
> > -		error = -EBUSY;
> > -		goto err_free_mem;
> > +		return -EBUSY;
> >  	}
> >  
> > -	opencores_kbd->addr = ioremap(res->start, resource_size(res));
> > +	opencores_kbd->addr = devm_ioremap(&pdev->dev, res->start,
> > +					   resource_size(res));
> 
> You could use devm_ioremap_resource() here and get rid of the call to
> devm_request_mem_region() and the check for !res above, i.e. something
> like:
> 
> 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> 	[...]
> 	opencores_kbd->addr = devm_ioremap_resource(&pdev->dev, res);
> 	if (!opencores_kbd->addr) {
> 		dev_err(&pdev->dev, "failed to remap I/O memory\n");
> 		return -ENXIO;
> 	}

You need to be careful with devm_ioremap_resource() ocnversions as it
returns ERR_PTR-encoded pointer on failures, not NULL.

I adjusted the patch to use devm_ioremap_resource() and applied.

Thanks.

-- 
Dmitry