Commit-ID: c1bacbae8192dd2a9ebadd22d793b68054f6c6e5
Gitweb: http://git.kernel.org/tip/c1bacbae8192dd2a9ebadd22d793b68054f6c6e5
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Sat, 8 Mar 2014 08:59:58 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 12 Mar 2014 16:00:24 +0100
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@xxxxxxxxxxxxx>
Cc: Jean-Jacques Hiblot <jjhiblot@xxxxxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1403080857160.18573@xxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/irq.h | 6 ++++++
kernel/irq/manage.c | 28 +++++++++++++++++++++++++++-
2 files changed, 33 insertions(+), 1 deletion(-)
diff --git a/include/linux/irq.h b/include/linux/irq.h
index 7dc1003..e675971 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 d3bf660..5d35cbe 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 */
--
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