[PATCH 10/17] soc: ti: pruss_intc: Add API to trigger a PRU sysevent

[Roger Quadros <rogerq@ti.com>]

From: Suman Anna <s-anna@ti.com>

The PRUSS INTC can generate an interrupt to various processor
subsystems on the SoC through a set of 64 possible PRU system
events. These system events can be used by PRU client drivers
or applications for event notifications/signalling between PRUs
and MPU or other processors. A new API, pruss_intc_trigger() is
provided to MPU-side PRU client drivers/applications to be able
to trigger an event/interrupt using IRQ numbers provided by the
PRUSS-INTC irqdomain chip.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/soc/ti/pruss_intc.c | 31 +++++++++++++++++++++++++++++++
 include/linux/pruss.h       |  7 +++++++
 2 files changed, 38 insertions(+)

diff --git a/drivers/soc/ti/pruss_intc.c b/drivers/soc/ti/pruss_intc.c
index df6b83b..6158b63 100644
--- a/drivers/soc/ti/pruss_intc.c
+++ b/drivers/soc/ti/pruss_intc.c
@@ -395,6 +395,37 @@ static void pruss_intc_irq_relres(struct irq_data *data)
 	module_put(THIS_MODULE);
 }
 
+/**
+ * pruss_intc_trigger() - trigger a PRU system event
+ * @irq: linux IRQ number associated with a PRU system event
+ *
+ * Trigger an interrupt by signalling a specific PRU system event.
+ * This can be used by PRUSS client users to raise/send an event to
+ * a PRU or any other core that is listening on the host interrupt
+ * mapped to that specific PRU system event. The @irq variable is the
+ * Linux IRQ number associated with a specific PRU system event that
+ * a client user/application uses. The interrupt mappings for this is
+ * provided by the PRUSS INTC irqchip instance.
+ *
+ * Returns 0 on success, or an error value upon failure.
+ */
+int pruss_intc_trigger(unsigned int irq)
+{
+	struct irq_desc *desc;
+
+	if (irq <= 0)
+		return -EINVAL;
+
+	desc = irq_to_desc(irq);
+	if (!desc)
+		return -EINVAL;
+
+	pruss_intc_irq_retrigger(&desc->irq_data);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pruss_intc_trigger);
+
 static int pruss_intc_irq_domain_map(struct irq_domain *d, unsigned int virq,
 				     irq_hw_number_t hw)
 {
diff --git a/include/linux/pruss.h b/include/linux/pruss.h
index 198ae25..768b698 100644
--- a/include/linux/pruss.h
+++ b/include/linux/pruss.h
@@ -41,6 +41,8 @@ int pruss_request_mem_region(struct pruss *pruss, enum pruss_mem mem_id,
 int pruss_release_mem_region(struct pruss *pruss,
 			     struct pruss_mem_region *region);
 
+int pruss_intc_trigger(unsigned int irq);
+
 #else
 
 static inline int pruss_request_mem_region(struct pruss *pruss,
@@ -56,6 +58,11 @@ static inline int pruss_release_mem_region(struct pruss *pruss,
 	return -ENOTSUPP;
 }
 
+static inline int pruss_intc_trigger(unsigned int irq)
+{
+	return -ENOTSUPP;
+}
+
 #endif /* CONFIG_TI_PRUSS */
 
 #endif /* __LINUX_PRUSS_H */
-- 
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