[PATCH] gpiolib: introduce for_each_gpio_in_chip macro

From: H Hartley Sweeten
Date: Fri Jul 31 2009 - 13:45:49 EST


gpiolib: introduce for_each_gpio_in_chip macro

There are a number of places in gpiolib where all the gpio's handled by a
chip are walked thru using a for() loop. This introduces a for_each_*
macro to clarify the code.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>

---

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 51a8d41..b060f73 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -56,6 +56,11 @@ struct gpio_desc {
};
static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];

+#define for_each_gpio_in_chip(__gpio, __chip) \
+ for ((__gpio) = (__chip)->base; \
+ (__gpio) < (__chip)->base + (__chip)->ngpio; \
+ (__gpio)++)
+
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
#ifdef CONFIG_DEBUG_FS
@@ -694,14 +699,14 @@ int gpiochip_add(struct gpio_chip *chip)
}

/* these GPIO numbers must not be managed by another gpio_chip */
- for (id = base; id < base + chip->ngpio; id++) {
+ for_each_gpio_in_chip(id, chip) {
if (gpio_desc[id].chip != NULL) {
status = -EBUSY;
break;
}
}
if (status == 0) {
- for (id = base; id < base + chip->ngpio; id++) {
+ for_each_gpio_in_chip(id, chip) {
gpio_desc[id].chip = chip;

/* REVISIT: most hardware initializes GPIOs as
@@ -744,14 +749,14 @@ int gpiochip_remove(struct gpio_chip *chip)

spin_lock_irqsave(&gpio_lock, flags);

- for (id = chip->base; id < chip->base + chip->ngpio; id++) {
+ for_each_gpio_in_chip(id, chip) {
if (test_bit(FLAG_REQUESTED, &gpio_desc[id].flags)) {
status = -EBUSY;
break;
}
}
if (status == 0) {
- for (id = chip->base; id < chip->base + chip->ngpio; id++)
+ for_each_gpio_in_chip(id, chip)
gpio_desc[id].chip = NULL;
}

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