Date: Wed, 3 Sep 2025 18:08:34 GMT From: Ahmad Khalifa <vexeduxr@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: ccc6cf3b67ed - main - libgpio: Add and document gpio interrupt utility functions Message-ID: <202509031808.583I8YlJ006232@gitrepo.freebsd.org>
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The branch main has been updated by vexeduxr: URL: https://cgit.FreeBSD.org/src/commit/?id=ccc6cf3b67edb9d50f6edb74c9b0e2c23f8b24d3 commit ccc6cf3b67edb9d50f6edb74c9b0e2c23f8b24d3 Author: Evgenii Ivanov <devivanov@proton.me> AuthorDate: 2025-09-03 12:13:59 +0000 Commit: Ahmad Khalifa <vexeduxr@FreeBSD.org> CommitDate: 2025-09-03 18:01:05 +0000 libgpio: Add and document gpio interrupt utility functions Add utility functions for configuring gpio interrupts and document file operations. Reviewed by: vexeduxr, ziaee Differential Revision: https://reviews.freebsd.org/D52102 --- lib/libgpio/Makefile | 4 ++- lib/libgpio/gpio.3 | 68 +++++++++++++++++++++++++++++++++++++++++++++++++-- lib/libgpio/gpio.c | 20 +++++++++++++++ lib/libgpio/libgpio.h | 13 ++++++++++ 4 files changed, 102 insertions(+), 3 deletions(-) diff --git a/lib/libgpio/Makefile b/lib/libgpio/Makefile index 42f822e97ba0..271595339792 100644 --- a/lib/libgpio/Makefile +++ b/lib/libgpio/Makefile @@ -27,6 +27,8 @@ MLINKS= gpio.3 gpio_open.3 \ gpio.3 gpio_pin_pulldown.3 \ gpio.3 gpio_pin_invin.3 \ gpio.3 gpio_pin_invout.3 \ - gpio.3 gpio_pin_pulsate.3 + gpio.3 gpio_pin_pulsate.3 \ + gpio.3 gpio_configure_events.3 \ + gpio.3 gpio_fileno.3 .include <bsd.lib.mk> 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: diff --git a/lib/libgpio/gpio.c b/lib/libgpio/gpio.c index e37ac1cdf8e8..c789bb34cacd 100644 --- a/lib/libgpio/gpio.c +++ b/lib/libgpio/gpio.c @@ -274,3 +274,23 @@ gpio_pin_pulsate(gpio_handle_t handle, gpio_pin_t pin) { return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULSATE)); } + +int +gpio_configure_events(gpio_handle_t handle, uint32_t report_type, + uint32_t fifo_size) +{ + struct gpio_event_config gpevent_config; + + gpevent_config.gp_report_type = report_type; + gpevent_config.gp_fifo_size = fifo_size; + if (ioctl(handle, GPIOCONFIGEVENTS, &gpevent_config) < 0) + return (-1); + + return (0); +} + +int +gpio_fileno(gpio_handle_t handle) +{ + return (handle); +} diff --git a/lib/libgpio/libgpio.h b/lib/libgpio/libgpio.h index 35651ecd8cca..abffc7b1b6ab 100644 --- a/lib/libgpio/libgpio.h +++ b/lib/libgpio/libgpio.h @@ -102,6 +102,19 @@ int gpio_pin_pulldown(gpio_handle_t, gpio_pin_t); int gpio_pin_invin(gpio_handle_t, gpio_pin_t); int gpio_pin_invout(gpio_handle_t, gpio_pin_t); int gpio_pin_pulsate(gpio_handle_t, gpio_pin_t); +/* + * GPIO event reporting configuration + * + * Set the event reporting type, the default being GPIO_EVENT_REPORT_DETAIL, + * and fifo size of 2 * number of pins belonging to the gpioc device instance. + * FIFO size can only be changed when report_type is GPIO_EVENT_REPORT_DETAIL. + */ +int gpio_configure_events(gpio_handle_t, uint32_t, uint32_t); +/* + * Retrieve the file descriptor associated with gpio_handle_t, which can + * be used for gpio interrupts. + */ +int gpio_fileno(gpio_handle_t); __END_DECLS
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