1 files changed, 29 insertions, 2 deletions

diff --git a/arch/arm/mach-at91rm9200/gpio.c b/arch/arm/mach-at91rm9200/gpio.c
index 2fd2ef583e4d..0e396feec468 100644
--- a/arch/arm/mach-at91rm9200/gpio.c
+++ b/arch/arm/mach-at91rm9200/gpio.c
@@ -159,6 +159,23 @@ int __init_or_module at91_set_deglitch(unsigned pin, int is_on)
 }
 EXPORT_SYMBOL(at91_set_deglitch);
 
+/*
+ * enable/disable the multi-driver; This is only valid for output and
+ * allows the output pin to run as an open collector output.
+ */
+int __init_or_module at91_set_multi_drive(unsigned pin, int is_on)
+{
+        void __iomem    *pio = pin_to_controller(pin);
+        unsigned        mask = pin_to_mask(pin);
+
+        if (!pio)
+                return -EINVAL;
+
+        __raw_writel(mask, pio + (is_on ? PIO_MDER : PIO_MDDR));
+        return 0;
+}
+EXPORT_SYMBOL(at91_set_multi_drive);
+
 /*--------------------------------------------------------------------------*/
 
 
@@ -257,8 +274,18 @@ static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs
                 gpio = &irq_desc[pin];
 
                 while (isr) {
-                        if (isr & 1)
-                                gpio->handle(pin, gpio, regs);
+                        if (isr & 1) {
+                                if (unlikely(gpio->disable_depth)) {
+                                        /*
+                                         * The core ARM interrupt handler lazily disables IRQs so
+                                         * another IRQ must be generated before it actually gets
+                                         * here to be disabled on the GPIO controller.
+                                         */
+                                        gpio_irq_mask(pin);
+                                }
+                                else
+                                        gpio->handle(pin, gpio, regs);
+                        }
                         pin++;
                         gpio++;
                         isr >>= 1;