Re: [PATCH 3/4] of/gpio: Implement GPIOLIB notifier hooks

From: Andrew Morton
Date: Mon Feb 08 2010 - 16:03:32 EST


On Fri, 5 Feb 2010 23:32:36 +0300
Anton Vorontsov <avorontsov@xxxxxxxxxxxxx> wrote:

> This patch implements GPIOLIB notifier hooks, and thus makes device-enabled
> GPIO chips (i.e. the ones that have gpio_chip->dev specified) automatically
> attached to the OpenFirmware subsystem. Which means that now we can handle
> I2C and SPI GPIO chips almost* transparently.
>
> * "Almost" because some chips still require platform data, and for these
> chips OF-glue is still needed, though with this support the glue will
> be much smaller.
>

We can clean this up a little with the WARN_ON trick:

diff -puN drivers/of/gpio.c~of-gpio-implement-gpiolib-notifier-hooks-fix drivers/of/gpio.c
--- a/drivers/of/gpio.c~of-gpio-implement-gpiolib-notifier-hooks-fix
+++ a/drivers/of/gpio.c
@@ -255,10 +255,8 @@ static int of_gpiochip_register_simple(s
{
struct of_gpio_chip *of_gc;

- if (np->data) {
- WARN_ON(1);
+ if (WARN_ON(np->data))
return -EBUSY;
- }

of_gc = kzalloc(sizeof(*of_gc), GFP_KERNEL);
if (!of_gc)
@@ -287,10 +285,8 @@ static int of_gpiochip_unregister(struct
{
struct of_gpio_chip *of_gc = np->data;

- if (!of_gc || of_gc->chip != chip) {
- WARN_ON(1);
+ if (WARN_ON(!of_gc || of_gc->chip != chip))
return -EINVAL;
- }

np->data = NULL;
kfree(of_gc);
_

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