gpio: dwapb: Refactor IRQ handler to use bit operations

Refactor IRQ handler in order to use for_each_set_bit() helper.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20200415141534.31240-3-andriy.shevchenko@linux.intel.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/gpio-dwapb.c

@@ -193,22 +193,21 @@ static void dwapb_toggle_trigger(struct dwapb_gpio *gpio, unsigned int offs)
 
 static u32 dwapb_do_irq(struct dwapb_gpio *gpio)
 {
-	u32 irq_status = dwapb_read(gpio, GPIO_INTSTATUS);
-	u32 ret = irq_status;
+	unsigned long irq_status;
+	int hwirq;
 
-	while (irq_status) {
-		int hwirq = fls(irq_status) - 1;
+	irq_status = dwapb_read(gpio, GPIO_INTSTATUS);
+	for_each_set_bit(hwirq, &irq_status, 32) {
 		int gpio_irq = irq_find_mapping(gpio->domain, hwirq);
+		u32 irq_type = irq_get_trigger_type(gpio_irq);
 
 		generic_handle_irq(gpio_irq);
-		irq_status &= ~BIT(hwirq);
 
-		if ((irq_get_trigger_type(gpio_irq) & IRQ_TYPE_SENSE_MASK)
-			== IRQ_TYPE_EDGE_BOTH)
+		if ((irq_type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH)
 			dwapb_toggle_trigger(gpio, hwirq);
 	}
 
-	return ret;
+	return irq_status;
 }
 
 static void dwapb_irq_handler(struct irq_desc *desc)