summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2014-03-08 08:59:58 +0100
committerThomas Gleixner <tglx@linutronix.de>2014-03-12 16:00:24 +0100
commitc1bacbae8192dd2a9ebadd22d793b68054f6c6e5 (patch)
treea2d402e83d75c77a390e47c0150078230bc0101a
parentfa389e220254c69ffae0d403eac4146171062d08 (diff)
genirq: Provide irq_request/release_resources chip callbacks
For certain irq types, e.g. gpios, it's necessary to request resources before starting up the irq. This might fail so we cannot use the irq_startup() callback because we might call the irq_set_type() callback before that which does not make sense when the resource is not available. Calling irq_startup() before irq_set_type() can lead to spurious interrupts which is not desired either. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jean-Jacques Hiblot <jjhiblot@traphandler.com> Cc: Grant Likely <grant.likely@linaro.org> Cc: linux-arm-kernel@lists.infradead.org Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1403080857160.18573@ionos.tec.linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--include/linux/irq.h6
-rw-r--r--kernel/irq/manage.c28
2 files changed, 33 insertions, 1 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 7dc10036eff5..e675971bdc3f 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -303,6 +303,10 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
* @irq_pm_shutdown: function called from core code on shutdown once per chip
* @irq_calc_mask: Optional function to set irq_data.mask for special cases
* @irq_print_chip: optional to print special chip info in show_interrupts
+ * @irq_request_resources: optional to request resources before calling
+ * any other callback related to this irq
+ * @irq_release_resources: optional to release resources acquired with
+ * irq_request_resources
* @flags: chip specific flags
*/
struct irq_chip {
@@ -336,6 +340,8 @@ struct irq_chip {
void (*irq_calc_mask)(struct irq_data *data);
void (*irq_print_chip)(struct irq_data *data, struct seq_file *p);
+ int (*irq_request_resources)(struct irq_data *data);
+ void (*irq_release_resources)(struct irq_data *data);
unsigned long flags;
};
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index d3bf660cb57f..5d35cbe22896 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -896,6 +896,23 @@ static void irq_setup_forced_threading(struct irqaction *new)
}
}
+static int irq_request_resources(struct irq_desc *desc)
+{
+ struct irq_data *d = &desc->irq_data;
+ struct irq_chip *c = d->chip;
+
+ return c->irq_request_resources ? c->irq_request_resources(d) : 0;
+}
+
+static void irq_release_resources(struct irq_desc *desc)
+{
+ struct irq_data *d = &desc->irq_data;
+ struct irq_chip *c = d->chip;
+
+ if (c->irq_release_resources)
+ c->irq_release_resources(d);
+}
+
/*
* Internal function to register an irqaction - typically used to
* allocate special interrupts that are part of the architecture.
@@ -1091,6 +1108,13 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
}
if (!shared) {
+ ret = irq_request_resources(desc);
+ if (ret) {
+ pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n",
+ new->name, irq, desc->irq_data.chip->name);
+ goto out_mask;
+ }
+
init_waitqueue_head(&desc->wait_for_threads);
/* Setup the type (level, edge polarity) if configured: */
@@ -1261,8 +1285,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id)
*action_ptr = action->next;
/* If this was the last handler, shut down the IRQ line: */
- if (!desc->action)
+ if (!desc->action) {
irq_shutdown(desc);
+ irq_release_resources(desc);
+ }
#ifdef CONFIG_SMP
/* make sure affinity_hint is cleaned up */