diff mbox series

[06/12] genirq: Introduce irq_chip_get/set_parent_state calls

Message ID 1573756521-27373-7-git-send-email-ilina@codeaurora.org (mailing list archive)
State Superseded
Headers show
Series Support wakeup capable GPIOs | expand

Commit Message

Lina Iyer Nov. 14, 2019, 6:35 p.m. UTC 
From: Maulik Shah <mkshah@codeaurora.org>

On certain QTI chipsets some GPIOs are direct-connect interrupts to the
GIC to be used as regular interrupt lines. When the GPIOs are not used
for interrupt generation the interrupt line is disabled. But disabling
the interrupt at GIC does not prevent the interrupt to be reported as
pending at GIC_ISPEND. Later, when drivers call enable_irq() on the
interrupt, an unwanted interrupt occurs.

Introduce get and set methods for irqchip's parent to clear it's pending
irq state. This then can be invoked by the GPIO interrupt controller on
the parents in it hierarchy to clear the interrupt before enabling the
interrupt.

Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
[updated commit text and minor code fixes]
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
Changes in RFC v2 -
	- Rephrase commit text
	- Address code review comments
---
 include/linux/irq.h |  6 ++++++
 kernel/irq/chip.c   | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

Comments

Stephen Boyd Nov. 15, 2019, 7:04 p.m. UTC | #1 
Quoting Lina Iyer (2019-11-14 10:35:15)
> From: Maulik Shah <mkshah@codeaurora.org>
> 
> On certain QTI chipsets some GPIOs are direct-connect interrupts to the
> GIC to be used as regular interrupt lines. When the GPIOs are not used
> for interrupt generation the interrupt line is disabled. But disabling
> the interrupt at GIC does not prevent the interrupt to be reported as
> pending at GIC_ISPEND. Later, when drivers call enable_irq() on the
> interrupt, an unwanted interrupt occurs.
> 
> Introduce get and set methods for irqchip's parent to clear it's pending
> irq state. This then can be invoked by the GPIO interrupt controller on
> the parents in it hierarchy to clear the interrupt before enabling the
> interrupt.
> 
> Signed-off-by: Maulik Shah <mkshah@codeaurora.org>
> [updated commit text and minor code fixes]
> Signed-off-by: Lina Iyer <ilina@codeaurora.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>
diff mbox series

Patch

diff --git a/include/linux/irq.h b/include/linux/irq.h
index fb301cf..7853eb9 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 b76703b..b3fa2d8 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1298,6 +1298,50 @@  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
+ *
+ * Conditional success, if the underlying irqchip does not implement it.
+ */
+int irq_chip_set_parent_state(struct irq_data *data,
+			      enum irqchip_irq_state which,
+			      bool val)
+{
+	data = data->parent_data;
+
+	if (!data || !data->chip->irq_set_irqchip_state)
+		return 0;
+
+	return data->chip->irq_set_irqchip_state(data, which, val);
+}
+EXPORT_SYMBOL_GPL(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
+ *
+ * Conditional success, if the underlying irqchip does not implement it.
+ */
+int irq_chip_get_parent_state(struct irq_data *data,
+			      enum irqchip_irq_state which,
+			      bool *state)
+{
+	data = data->parent_data;
+
+	if (!data || !data->chip->irq_get_irqchip_state)
+		return 0;
+
+	return data->chip->irq_get_irqchip_state(data, which, state);
+}
+EXPORT_SYMBOL_GPL(irq_chip_get_parent_state);
+
+/**
  * irq_chip_enable_parent - Enable the parent interrupt (defaults to unmask if
  * NULL)
  * @data:	Pointer to interrupt specific data