[PATCH] gpiolib: introduce for_each_gpio_in_chip macro

[H Hartley Sweeten <hartleys@visionengravers.com>]

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@visionengravers.com>

---

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;
 	}