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

[Tobias Klauser <tklauser@distanz.ch>]

On 2014-10-07 at 18:17:16 +0200, Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> 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.

Ah yes of course, I was a bit too quick with my top-of-the-head
conversion. Thanks for fixing it up.