2008-02-10 19:12:06

by Guennadi Liakhovetski

Subject: [PATCH] introduce is_valid_gpio() predicate and use it in gpiolib.c

Introduce a is_valid_gpio() predicate to be used in gpiolib core and
drivers.

Signed-off-by: Guennadi Liakhovetski <[email protected]>

---

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d8db2f8..5390f46 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -96,7 +96,7 @@ int gpiochip_add(struct gpio_chip *chip)
* dynamic allocation. We don't currently support that.
*/

- if (chip->base < 0 || (chip->base + chip->ngpio) >= ARCH_NR_GPIOS) {
+ if (chip->base < 0 || !is_valid_gpio(chip->base + chip->ngpio)) {
status = -EINVAL;
goto fail;
}
@@ -171,7 +171,7 @@ int gpio_request(unsigned gpio, const char *label)

spin_lock_irqsave(&gpio_lock, flags);

- if (gpio >= ARCH_NR_GPIOS)
+ if (!is_valid_gpio(gpio))
goto done;
desc = &gpio_desc[gpio];
if (desc->chip == NULL)
@@ -201,7 +201,7 @@ void gpio_free(unsigned gpio)
unsigned long flags;
struct gpio_desc *desc;

- if (gpio >= ARCH_NR_GPIOS) {
+ if (!is_valid_gpio(gpio)) {
WARN_ON(extra_checks);
return;
}
@@ -236,7 +236,7 @@ const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
{
unsigned gpio = chip->base + offset;

- if (gpio >= ARCH_NR_GPIOS || gpio_desc[gpio].chip != chip)
+ if (!is_valid_gpio(gpio) || gpio_desc[gpio].chip != chip)
return NULL;
if (test_bit(FLAG_REQUESTED, &gpio_desc[gpio].flags) == 0)
return NULL;
@@ -267,7 +267,7 @@ int gpio_direction_input(unsigned gpio)

spin_lock_irqsave(&gpio_lock, flags);

- if (gpio >= ARCH_NR_GPIOS)
+ if (!is_valid_gpio(gpio))
goto fail;
chip = desc->chip;
if (!chip || !chip->get || !chip->direction_input)
@@ -305,7 +305,7 @@ int gpio_direction_output(unsigned gpio, int value)

spin_lock_irqsave(&gpio_lock, flags);

- if (gpio >= ARCH_NR_GPIOS)
+ if (!is_valid_gpio(gpio))
goto fail;
chip = desc->chip;
if (!chip || !chip->set || !chip->direction_output)
@@ -522,7 +522,7 @@ static int gpiolib_show(struct seq_file *s, void *unused)

/* REVISIT this isn't locked against gpio_chip removal ... */

- for (gpio = 0; gpio < ARCH_NR_GPIOS; gpio++) {
+ for (gpio = 0; is_valid_gpio(gpio); gpio++) {
if (chip == gpio_desc[gpio].chip)
continue;
chip = gpio_desc[gpio].chip;
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index f29a502..87dab12 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -16,6 +16,8 @@
#define ARCH_NR_GPIOS 256
#endif

+#define is_valid_gpio(gpio) ((unsigned int)(gpio) < ARCH_NR_GPIOS)
+
struct seq_file;

/**

2008-02-10 19:18:19

by David Brownell

Subject: Re: [PATCH] introduce is_valid_gpio() predicate and use it in gpiolib.c

I like this, but can't resist making the "Andrew Comment":

> --- a/include/asm-generic/gpio.h
> +++ b/include/asm-generic/gpio.h
> @@ -16,6 +16,8 @@
> #define ARCH_NR_GPIOS 256
> #endif
>
> +#define is_valid_gpio(gpio) ((unsigned int)(gpio) < ARCH_NR_GPIOS)

Please make this an inline C function. :)


> +
> struct seq_file;
>
> /**
>