gpio/langwell: Simplify demux loop

Use __ffs() to find the pending interrupt source instead of looping 32
times.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Alek Du <alek.du@intel.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c
index 6efc4e60aca7..f658af016f44 100644
--- a/drivers/gpio/langwell_gpio.c
+++ b/drivers/gpio/langwell_gpio.c
@@ -191,19 +191,20 @@ static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
         struct lnw_gpio *lnw = irq_data_get_irq_handler_data(data);
         struct irq_chip *chip = irq_data_get_irq_chip(data);
         u32 base, gpio, gedr_v;
+        unsigned long pending;
         void __iomem *gedr;
 
         /* check GPIO controller to check which pin triggered the interrupt */
         for (base = 0; base < lnw->chip.ngpio; base += 32) {
                 gedr = gpio_reg(&lnw->chip, base, GEDR);
-                gedr_v = readl(gedr);
+                gedr_v = pending = readl(gedr);
                 if (!gedr_v)
                         continue;
-                for (gpio = base; gpio < base + 32; gpio++)
-                        if (gedr_v & BIT(gpio % 32)) {
-                                pr_debug("pin %d triggered\n", gpio);
-                                generic_handle_irq(lnw->irq_base + gpio);
-                        }
+                while (pending) {
+                        gpio = __ffs(pending) - 1;
+                        pending &= ~BIT(gpio);
+                        generic_handle_irq(lnw->irq_base + base + gpio);
+                }
                 /* clear the edge detect status bit */
                 writel(gedr_v, gedr);
         }