Interrupt Management Services
[Driver Development API]

Collaboration diagram for Interrupt Management Services:

RTDM_IRQTYPE_xxx
Interrupt registrations flags
#define	RTDM_IRQTYPE_SHARED   XN_ISR_SHARED
	Enable IRQ-sharing with other real-time drivers.
#define	RTDM_IRQTYPE_EDGE   XN_ISR_EDGE
	Mark IRQ as edge-triggered, relevant for correct handling of shared edge-triggered IRQs.
RTDM_IRQ_xxx
Return flags of interrupt handlers
#define	RTDM_IRQ_NONE   XN_ISR_NONE
	Unhandled interrupt.
#define	RTDM_IRQ_HANDLED   XN_ISR_HANDLED
	Denote handled interrupt.
Defines
#define	rtdm_irq_get_arg(irq_handle, type)   ((type *)irq_handle->cookie)
	Retrieve IRQ handler argument.
Typedefs
typedef int(*	rtdm_irq_handler_t )(rtdm_irq_t *irq_handle)
	Interrupt handler.
Functions
int	rtdm_irq_request (rtdm_irq_t *irq_handle, unsigned int irq_no, rtdm_irq_handler_t handler, unsigned long flags, const char *device_name, void *arg)
	Register an interrupt handler.
int	rtdm_irq_free (rtdm_irq_t *irq_handle)
	Release an interrupt handler.
int	rtdm_irq_enable (rtdm_irq_t *irq_handle)
	Enable interrupt line.
int	rtdm_irq_disable (rtdm_irq_t *irq_handle)
	Disable interrupt line.

---

Define Documentation

#define rtdm_irq_get_arg	(	irq_handle,
		type		)	((type *)irq_handle->cookie)

Retrieve IRQ handler argument.

Parameters:

	irq_handle	IRQ handle
	type	Type of the pointer to return

Returns:

The argument pointer registered on rtdm_irq_request() is returned, type-casted to the specified type.

Environments:

This service can be called from:

• Interrupt service routine

Rescheduling: never.

---

Typedef Documentation

typedef int(* rtdm_irq_handler_t)(rtdm_irq_t *irq_handle)

Interrupt handler.

Parameters:

[in]

irq_handle

IRQ handle as returned by rtdm_irq_request()

Returns:

0 or a combination of RTDM_IRQ_xxx flags

---

Function Documentation

int rtdm_irq_disable

(

rtdm_irq_t *

irq_handle

)

Disable interrupt line.

Parameters:

[in,out]

irq_handle

IRQ handle as returned by rtdm_irq_request()

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Interrupt service routine
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

int rtdm_irq_enable

(

rtdm_irq_t *

irq_handle

)

Enable interrupt line.

Parameters:

[in,out]

irq_handle

IRQ handle as returned by rtdm_irq_request()

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Interrupt service routine
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: possible.

int rtdm_irq_free

(

rtdm_irq_t *

irq_handle

)

Release an interrupt handler.

Parameters:

[in,out]

irq_handle

IRQ handle as returned by rtdm_irq_request()

Returns:

0 on success, otherwise negative error code

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

int rtdm_irq_request	(	rtdm_irq_t *	irq_handle,
		unsigned int	irq_no,
		rtdm_irq_handler_t	handler,
		unsigned long	flags,
		const char *	device_name,
		void *	arg
	)

Register an interrupt handler.

This function registers the provided handler with an IRQ line and enables the line.

Parameters:

[in,out]	irq_handle	IRQ handle
[in]	irq_no	Line number of the addressed IRQ
[in]	handler	Interrupt handler
[in]	flags	Registration flags, see RTDM_IRQTYPE_xxx for details
[in]	device_name	Device name to show up in real-time IRQ lists
[in]	arg	Pointer to be passed to the interrupt handler on invocation

Returns:

0 on success, otherwise:

• -EINVAL is returned if an invalid parameter was passed.

• -EBUSY is returned if the specified IRQ line is already in use.

Environments:

This service can be called from:

• Kernel module initialization/cleanup code
• Kernel-based task
• User-space task (RT, non-RT)

Rescheduling: never.

References xnintr_attach(), xnintr_detach(), xnintr_enable(), and xnintr_init().