Commit 4a169a95 authored by Maulik Shah's avatar Maulik Shah Committed by Marc Zyngier
Browse files

genirq: Introduce irq_chip_get/set_parent_state calls 



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: default avatarMaulik Shah <mkshah@codeaurora.org>
Signed-off-by: default avatarLina Iyer <ilina@codeaurora.org>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1573855915-9841-7-git-send-email-ilina@codeaurora.org

[updated commit text and minor code fixes]
parent d46bca2b

include/linux/irq.h

+6 −0
Original line number Diff line number Diff line
@@ -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);

kernel/irq/chip.c

+44 −0
Original line number Diff line number Diff line
@@ -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

 *

 * 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)

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