/* General Shared Interrupt handling function interface
*
* The functions does not manipulate the IRQ controller or the
* interrupt level of the CPU. It simply helps the caller with
* managing shared interrupts where multiple interrupt routines
* share on interrupt vector/number.
*
* COPYRIGHT (c) 2008.
* Cobham Gaisler AB.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#ifndef __GENIRQ_H__
#define __GENIRQ_H__
#ifdef __cplusplus
extern "C" {
#endif
typedef void (*genirq_handler)(void *arg);
typedef void* genirq_t;
struct genirq_stats {
unsigned int irq_cnt;
};
/* Initialize the genirq interface. Must be the first function
* called.
*
* Returns zero on success, otherwise failure.
*/
extern genirq_t genirq_init(int number_of_irqs);
/* Free the dynamically allocated memory that the genirq interface has
* allocated.
*
* Returns zero on success, otherwise failure.
*/
extern void genirq_destroy(genirq_t d);
/* Check IRQ number validity
*
* Returns zero for valid IRQ numbers, -1 of invalid IRQ numbers.
*/
extern int genirq_check(genirq_t d, int irq);
/* Register shared interrupt handler.
*
* \param irq The interrupt number to register ISR on
* \param isr The interrupt service routine called upon IRQ
* \param arg The argument given to isr() when called.
*
* Return Values
* -1 = Failed
* 0 = Handler registered Successfully, first handler on this IRQ
* 1 = Handler registered Successfully, _not_ first handler on this IRQ
*/
extern int genirq_register(genirq_t d, int irq, genirq_handler isr, void *arg);
/* Unregister an previous registered interrupt handler
*
* Return Values
* -1 = ISR not registered before
* 0 = ISR unregistered
* 1 = Unable to unregister enabled ISR
*/
extern int genirq_unregister(genirq_t d, int irq, genirq_handler isr, void *arg);
/* Enables IRQ only for this isr[arg] combination. Records if this
* is the first interrupt enable, only then must interrupts be enabled
* on the interrupt controller.
*
* IRQs must be disabled before entering this function.
*
* Return values
* -1 = Failure, for example isr[arg] not registered on this irq
* 0 = IRQ must be enabled, it is the first IRQ handler to be enabled
* 1 = IRQ has already been enabled, either by isr[arg] or by another handler
*/
extern int genirq_enable(genirq_t d, int irq, genirq_handler isr, void *arg);
/* Disables IRQ only for this isr[arg] combination. Records if this
* is the only interrupt handler that is enabled on this IRQ, only then
* must interrupts be disabled on the interrupt controller.
*
* IRQs must be disabled before entering this function.
*
* Return values
* -1 = Failure, for example isr[arg] not registered on this irq
* 0 = IRQ must be disabled, no ISR are enabled for this IRQ
* 1 = ISR has already been disabled, or other ISRs are still enabled
*/
extern int genirq_disable(genirq_t d, int irq, genirq_handler isr, void *arg);
/* Must be called by user when an IRQ has fired, the argument 'irq'
* is the IRQ number of the IRQ which was fired.
*/
extern void genirq_doirq(genirq_t d, int irq);
#ifdef __cplusplus
}
#endif
#endif
