File syn_exti.h¶

FileList > drivers > syn_exti.h

GPIO interrupt dispatcher — register callbacks per pin. More...

#include "../common/syn_defs.h"
#include "../port/syn_port_exti.h"
#include <stdbool.h>
#include <stdint.h>

Public Types¶

Type	Name
typedef void(*	SYN_EXTI_Callback

Public Functions¶

Type	Name
size_t	syn_exti_count (void) Get the number of registered callbacks.
void	syn_exti_disable (SYN_GPIO_Pin pin) Disable interrupt for a pin.
void	syn_exti_enable (SYN_GPIO_Pin pin) Enable interrupt for a registered pin.
void	syn_exti_init (void)
void	syn_exti_irq_handler (SYN_GPIO_Pin pin) IRQ handler — call from platform ISR.
SYN_Status	syn_exti_register (SYN_GPIO_Pin pin, SYN_EXTI_Edge edge, SYN_EXTI_Callback cb, void * ctx) Register a callback for a pin interrupt.
void	syn_exti_unregister (SYN_GPIO_Pin pin) Unregister a pin callback.

Macros¶

Type	Name
define	SYN_EXTI_MAX_PINS `16`

Detailed Description¶

Thin layer over the EXTI port. Registers a callback for each pin; when the platform ISR fires, call syn_exti_irq_handler(pin) and the dispatcher invokes the registered callback.

Optionally integrates with the work queue for deferred processing (recommended for non-trivial handlers).

** **

void on_button_press(SYN_GPIO_Pin pin, void *ctx) {
    // runs in ISR context — keep it fast!
    *(bool *)ctx = true;
}

syn_exti_init();
syn_exti_register(PIN_BUTTON, SYN_EXTI_FALLING,
                   on_button_press, &button_flag);
syn_exti_enable(PIN_BUTTON);

** **

// STM32 example:
void EXTI0_IRQHandler(void) {
    if (EXTI->PR & (1 << 0)) {
        EXTI->PR = (1 << 0);  // clear
        syn_exti_irq_handler(0);
    }
}

Public Types Documentation¶

typedef SYN_EXTI_Callback¶

typedef void(* SYN_EXTI_Callback) (SYN_GPIO_Pin pin, void *ctx);

EXTI callback — called from ISR context unless deferred.

Public Functions Documentation¶

function syn_exti_count¶

Get the number of registered callbacks.

size_t syn_exti_count (
    void
)

Returns:

Registration count.

function syn_exti_disable¶

Disable interrupt for a pin.

void syn_exti_disable (
    SYN_GPIO_Pin pin
)

Parameters:

pin GPIO pin.

function syn_exti_enable¶

Enable interrupt for a registered pin.

void syn_exti_enable (
    SYN_GPIO_Pin pin
)

Parameters:

pin GPIO pin.

function syn_exti_init¶

void syn_exti_init (
    void
)

Initialize the EXTI dispatcher.

function syn_exti_irq_handler¶

IRQ handler — call from platform ISR.

void syn_exti_irq_handler (
    SYN_GPIO_Pin pin
)

Looks up the registered callback for pin and invokes it. This is the glue between hardware ISR and the dispatcher.

Parameters:

pin GPIO pin that triggered the interrupt.

function syn_exti_register¶

Register a callback for a pin interrupt.

SYN_Status syn_exti_register (
    SYN_GPIO_Pin pin,
    SYN_EXTI_Edge edge,
    SYN_EXTI_Callback cb,
    void * ctx
)

Parameters:

pin GPIO pin.
edge Trigger edge.
cb Callback (runs in ISR context).
ctx User context passed to callback.

Returns:

SYN_OK, or SYN_ERROR if table full.

function syn_exti_unregister¶

Unregister a pin callback.

void syn_exti_unregister (
    SYN_GPIO_Pin pin
)

Parameters:

pin GPIO pin.

Macro Definition Documentation¶

define SYN_EXTI_MAX_PINS¶

#define SYN_EXTI_MAX_PINS `16`

Max number of EXTI-enabled pins

The documentation for this class was generated from the following file src/syntropic/drivers/syn_exti.h