1 files changed, 10 insertions, 5 deletions

diff --git a/arch/arm/mach-at91/gpio.c b/arch/arm/mach-at91/gpio.c
index 9b0447c3d59b..2f7d4977dce9 100644
--- a/arch/arm/mach-at91/gpio.c
+++ b/arch/arm/mach-at91/gpio.c
@@ -490,7 +490,8 @@ postcore_initcall(at91_gpio_debugfs_init);
 
 /*--------------------------------------------------------------------------*/
 
-/* This lock class tells lockdep that GPIO irqs are in a different
+/*
+ * This lock class tells lockdep that GPIO irqs are in a different
  * category than their parents, so it won't report false recursion.
  */
 static struct lock_class_key gpio_lock_class;
@@ -509,9 +510,6 @@ void __init at91_gpio_irq_setup(void)
                 unsigned        id = this->id;
                 unsigned        i;
 
-                /* enable PIO controller's clock */
-                clk_enable(this->clock);
-
                 __raw_writel(~0, this->regbase + PIO_IDR);
 
                 for (i = 0, pin = this->chipbase; i < 32; i++, pin++) {
@@ -556,7 +554,14 @@ void __init at91_gpio_init(struct at91_gpio_bank *data, int nr_banks)
                 data->chipbase = PIN_BASE + i * 32;
                 data->regbase = data->offset + (void __iomem *)AT91_VA_BASE_SYS;
 
-                /* AT91SAM9263_ID_PIOCDE groups PIOC, PIOD, PIOE */
+                /* enable PIO controller's clock */
+                clk_enable(data->clock);
+
+                /*
+                 * Some processors share peripheral ID between multiple GPIO banks.
+                 *  SAM9263 (PIOC, PIOD, PIOE)
+                 *  CAP9 (PIOA, PIOB, PIOC, PIOD)
+                 */
                 if (last && last->id == data->id)
                         last->next = data;
         }