[PATCH RFC 07/14] genirq: Introduce irq_chip_get/set_parent_state calls

From: Lina Iyer
Date: Thu Aug 29 2019 - 14:37:45 EST


From: Maulik Shah <mkshah@xxxxxxxxxxxxxx>

On certain QTI chipsets some GPIOs are direct-connect interrupts
to the GIC.

Even when GPIOs are not used for interrupt generation and interrupt
line is disabled, it does not prevent interrupt to get pending at
GIC_ISPEND. When drivers call enable_irq unwanted interrupt occures.

Introduce irq_chip_get/set_parent_state calls to clear pending irq
which can get called within irq_enable of child irq chip to clear
any pending irq before enabling.

Signed-off-by: Maulik Shah <mkshah@xxxxxxxxxxxxxx>
---
include/linux/irq.h | 6 ++++++
kernel/irq/chip.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 50 insertions(+)

diff --git a/include/linux/irq.h b/include/linux/irq.h
index fb301cf29148..7853eb9301f2 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -610,6 +610,12 @@ extern int irq_chip_pm_put(struct irq_data *data);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
extern void handle_fasteoi_ack_irq(struct irq_desc *desc);
extern void handle_fasteoi_mask_irq(struct irq_desc *desc);
+extern int irq_chip_set_parent_state(struct irq_data *data,
+ enum irqchip_irq_state which,
+ bool val);
+extern int irq_chip_get_parent_state(struct irq_data *data,
+ enum irqchip_irq_state which,
+ bool *state);
extern void irq_chip_enable_parent(struct irq_data *data);
extern void irq_chip_disable_parent(struct irq_data *data);
extern void irq_chip_ack_parent(struct irq_data *data);
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index b76703b2c0af..6bb5b22bb0a7 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1297,6 +1297,50 @@ EXPORT_SYMBOL_GPL(handle_fasteoi_mask_irq);

#endif /* CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS */

+/**
+ * irq_chip_set_parent_state - set the state of a parent interrupt.
+ * @data: Pointer to interrupt specific data
+ * @which: State to be restored (one of IRQCHIP_STATE_*)
+ * @val: Value corresponding to @which
+ *
+ */
+int irq_chip_set_parent_state(struct irq_data *data,
+ enum irqchip_irq_state which,
+ bool val)
+{
+ data = data->parent_data;
+ if (!data)
+ return 0;
+
+ if (data->chip->irq_set_irqchip_state)
+ return data->chip->irq_set_irqchip_state(data, which, val);
+
+ return 0;
+}
+EXPORT_SYMBOL(irq_chip_set_parent_state);
+
+/**
+ * irq_chip_get_parent_state - get the state of a parent interrupt.
+ * @data: Pointer to interrupt specific data
+ * @which: one of IRQCHIP_STATE_* the caller wants to know
+ * @state: a pointer to a boolean where the state is to be stored
+ *
+ */
+int irq_chip_get_parent_state(struct irq_data *data,
+ enum irqchip_irq_state which,
+ bool *state)
+{
+ data = data->parent_data;
+ if (!data)
+ return 0;
+
+ if (data->chip->irq_get_irqchip_state)
+ return data->chip->irq_get_irqchip_state(data, which, state);
+
+ return 0;
+}
+EXPORT_SYMBOL(irq_chip_get_parent_state);
+
/**
* irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
* NULL)
--
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