diff options
Diffstat (limited to 'lib/libgpio/gpio.3')
| -rw-r--r-- | lib/libgpio/gpio.3 | 68 |
1 files changed, 66 insertions, 2 deletions
diff --git a/lib/libgpio/gpio.3 b/lib/libgpio/gpio.3 index ed2860776c3c..cb413b838bd0 100644 --- a/lib/libgpio/gpio.3 +++ b/lib/libgpio/gpio.3 @@ -23,7 +23,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd July 1, 2015 +.Dd September 3, 2025 .Dt GPIO 3 .Os .Sh NAME @@ -79,6 +79,10 @@ .Fn gpio_pin_invout "gpio_handle_t handle" "gpio_pin_t pin" .Ft int .Fn gpio_pin_pulsate "gpio_handle_t handle" "gpio_pin_t pin" +.Ft int +.Fn gpio_configure_events "gpio_handle_t handle" "uint32_t report_type" "uint32_t fifo_size" +.Ft int +.Fn gpio_fileno "gpio_handle_t handle" .Sh DESCRIPTION The .Nm libgpio @@ -125,7 +129,7 @@ The pin number should also be passed in through the variable. All other structure members will be ignored by this function. The list of flags can be found in -.Pa /usr/include/sys/gpio.h . +.In sys/gpio.h . .Pp The get or set the state of a GPIO pin, the functions .Fn gpio_pin_get @@ -156,6 +160,66 @@ and .Fn gpio_pin_pulsate are wrappers around .Fn gpio_pin_set_flags . +.Pp +The function +.Fn gpio_configure_events +configures the interrupt report type and FIFO size for buffered +gpio interrupts. +The report type is specified by one of the following values: +.Bl -tag -width indent +.It Dv GPIO_EVENT_REPORT_DETAIL +Events are reported using +.Ft struct gpio_event_detail . +.It Dv GPIO_EVENT_REPORT_SUMMARY +Events are reported using +.Ft struct gpio_event_summary . +.El +.Pp +By default, the report type is +.Dv GPIO_EVENT_REPORT_DETAIL , +with a default FIFO size of 2 * number of pins belonging to the +.Ft gpio_device_t +instance. +The FIFO argument is only meaningful when +.Fa report_type +is +.Dv GPIO_EVENT_REPORT_DETAIL . +The structures associated with each report type are defined in +.In sys/gpio.h . +This setting is tracked on a per device instance basis. +The FIFO size cannot be reduced below the default value, +nor can it be decreased after it has been increased. +If any pin on the device has already been configured for interrupts, +.Fn gpio_configure_events +fails and returns -1. +On success 0 is returned. +.Pp +The function +.Fn gpio_fileno +returns the file descriptor associated with the +.Ft gpio_handle_t +instance. +.Pp +File operations have the following semantics: +.Bl -tag -width "read (2)" +.It Xr read 2 +Read one or more gpio interrupts that have occured +since the last successful +.Xr read 2 . +The results are placed into the output buffer +of the type previously established via +.Fn gpio_configure_events . +If there are no pending interrupts, +.Xr read 2 +blocks until an interrupt occurs, unless +.Dv O_NONBLOCK +is set. +.It Xr poll 2 +When receiving notification via +.Xr poll 2 +or similar interfaces, the file descriptor becomes readable when +one or more gpio interrupts are pending. +.El .Sh EXAMPLES The following example shows how to configure pin 16 as output and then drive it high: |