[PATCH 2/5] gpio/omap: Use devm_ API and add request_mem_region

[Grant Likely]

On Thu, Feb 16, 2012 at 11:11:52AM +0530, DebBarma, Tarun Kanti wrote:
> Hi Benoit,
> 
> On Wed, Feb 15, 2012 at 9:34 PM, Benoit Cousson <b-cousson at ti.com> wrote:
> > Replace the regular kzalloc and ioremap with the devm_ equivalent
> > to simplify error handling.
> >
> > Add the missing devm_request_mem_region to reserve the region used
> > by the driver.
> >
> > Signed-off-by: Benoit Cousson <b-cousson at ti.com>
> > Cc: Tarun Kanti DebBarma <tarun.kanti at ti.com>
> > ---
> >  drivers/gpio/gpio-omap.c |   35 +++++++++++++++--------------------
> >  1 files changed, 15 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
> > index a0c3e03..c3a9dc8 100644
> > --- a/drivers/gpio/gpio-omap.c
> > +++ b/drivers/gpio/gpio-omap.c
> > @@ -19,7 +19,7 @@
> >  #include <linux/err.h>
> >  #include <linux/clk.h>
> >  #include <linux/io.h>
> > -#include <linux/slab.h>
> > +#include <linux/device.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/pm.h>
> >
> > @@ -1052,23 +1052,19 @@ static int __devinit omap_gpio_probe(struct platform_device *pdev)
> >        struct gpio_bank *bank;
> >        int ret = 0;
> >
> > -       if (!dev->platform_data) {
> > -               ret = -EINVAL;
> > -               goto err_exit;
> > -       }
> > +       if (!dev->platform_data)
> > +               return -EINVAL;
> >
> > -       bank = kzalloc(sizeof(struct gpio_bank), GFP_KERNEL);
> > +       bank = devm_kzalloc(&pdev->dev, sizeof(struct gpio_bank), GFP_KERNEL);
> >        if (!bank) {
> >                dev_err(dev, "Memory alloc failed\n");
> > -               ret = -ENOMEM;
> > -               goto err_exit;
> > +               return -ENOMEM;
> >        }
> >
> >        res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> >        if (unlikely(!res)) {
> >                dev_err(dev, "Invalid IRQ resource\n");
> > -               ret = -ENODEV;
> > -               goto err_free;
> > +               return -ENODEV;
> How is the memory allocated to 'bank' getting freed before return -ENODEV?

The magic of devm_*() functions.  Anything allocated by those functions is
automatically freed on either probe failure or driver removal.

g.