[PATCH] irq/irq_sim: implement irq_sim_baseirq()

[Bartosz Golaszewski <brgl@bgdev.pl>]

Some users need to access the base of the allocated interrupt range.
Although this can be calculated manually, it's more elegant to expose
an interface for that.

Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
---
When porting the iio_dummy_evgen to using irq_sim I needed to manually
calculate the base interrupt number. If this gets merged, I'll update
the iio driver for 4.16.

 include/linux/irq_sim.h |  1 +
 kernel/irq/irq_sim.c    | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/linux/irq_sim.h b/include/linux/irq_sim.h
index 0380d899b955..246f593face8 100644
--- a/include/linux/irq_sim.h
+++ b/include/linux/irq_sim.h
@@ -40,5 +40,6 @@ int devm_irq_sim_init(struct device *dev, struct irq_sim *sim,
 void irq_sim_fini(struct irq_sim *sim);
 void irq_sim_fire(struct irq_sim *sim, unsigned int offset);
 int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset);
+int irq_sim_baseirq(struct irq_sim *sim);
 
 #endif /* _LINUX_IRQ_SIM_H */
diff --git a/kernel/irq/irq_sim.c b/kernel/irq/irq_sim.c
index 24caabf1a0f7..9438599d0fc9 100644
--- a/kernel/irq/irq_sim.c
+++ b/kernel/irq/irq_sim.c
@@ -162,3 +162,14 @@ int irq_sim_irqnum(struct irq_sim *sim, unsigned int offset)
 	return sim->irqs[offset].irqnum;
 }
 EXPORT_SYMBOL_GPL(irq_sim_irqnum);
+
+/**
+ * irq_sim_baseirq - Get the base interrupt number.
+ *
+ * @sim:        The interrupt simulator object.
+ */
+int irq_sim_baseirq(struct irq_sim *sim)
+{
+	return irq_sim_irqnum(sim, 0);
+}
+EXPORT_SYMBOL_GPL(irq_sim_baseirq);
-- 
2.13.2