Many IRQs are associated with GPIO pins. When the pin is used as an IRQ,
it can't be used as anything else; it should be requested. Enhance the
core interrupt code to call gpio_request() and gpio_direction_input() for
any IRQ that is also a GPIO. This prevents duplication of these calls in
each driver that uses an IRQ.

Signed-off-by: Stephen Warren <[email protected]>
---
 kernel/irq/manage.c |   23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0a7840a..6e2db72 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -7,6 +7,7 @@
  * This file contains driver APIs to the irq subsystem.
  */
 
+#include <linux/gpio.h>
 #include <linux/irq.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
@@ -875,7 +876,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct 
irqaction *new)
        struct irqaction *old, **old_ptr;
        const char *old_name = NULL;
        unsigned long flags, thread_mask = 0;
-       int ret, nested, shared = 0;
+       int ret, nested, shared = 0, gpio = -1;
        cpumask_var_t mask;
 
        if (!desc)
@@ -978,6 +979,16 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, 
struct irqaction *new)
                        old = *old_ptr;
                } while (old);
                shared = 1;
+       } else {
+               gpio = irq_to_gpio(irq);
+               if (gpio_is_valid(gpio)) {
+                       ret = gpio_request(gpio, new->name);
+                       if (ret < 0)
+                               goto out_mask;
+                       ret = gpio_direction_input(gpio);
+                       if (ret < 0)
+                               goto out_mask;
+               }
        }
 
        /*
@@ -1083,6 +1094,8 @@ mismatch:
        ret = -EBUSY;
 
 out_mask:
+       if (gpio_is_valid(gpio))
+               gpio_free(gpio);
        raw_spin_unlock_irqrestore(&desc->lock, flags);
        free_cpumask_var(mask);
 
@@ -1127,6 +1140,7 @@ static struct irqaction *__free_irq(unsigned int irq, 
void *dev_id)
        struct irq_desc *desc = irq_to_desc(irq);
        struct irqaction *action, **action_ptr;
        unsigned long flags;
+       int gpio;
 
        WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq);
 
@@ -1165,8 +1179,13 @@ static struct irqaction *__free_irq(unsigned int irq, 
void *dev_id)
 #endif
 
        /* If this was the last handler, shut down the IRQ line: */
-       if (!desc->action)
+       if (!desc->action) {
                irq_shutdown(desc);
+               /* If the IRQ line is a GPIO, it's no longer in use */
+               gpio = irq_to_gpio(irq);
+               if (gpio_is_valid(gpio))
+                       gpio_free(gpio);
+       }
 
 #ifdef CONFIG_SMP
        /* make sure affinity_hint is cleaned up */
-- 
1.7.0.4

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