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>
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 @@
* @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 @@
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;
};