General-Purpose Input/Output (GPIO)

Overview

Configuration Options

Related configuration options:

API Reference

Related code samples

Basic thread manipulation

Spawn multiple threads that blink LEDs and print information to the console.

Blinky

Blink an LED forever using the GPIO API.

Button

Handle GPIO inputs with interrupts.

GPIO with custom Devicetree binding

Use custom Devicetree binding to control a GPIO.

HD44780 LCD controller

Control an HD44780-based LCD display using GPIO pins.

X-NUCLEO-53L0A1 shield

Interact with the 7-segment display and VL53L0X ranging sensor of an X-NUCLEO-53L0A1 shield.

group gpio_interface

GPIO Driver APIs.

Since

1.0

Version

1.0.0

GPIO input/output configuration flags

GPIO_INPUT

Enables pin as input.

GPIO_OUTPUT

Enables pin as output, no change to the output state.

GPIO_DISCONNECTED

Disables pin for both input and output.

GPIO_OUTPUT_LOW

Configures GPIO pin as output and initializes it to a low state.

GPIO_OUTPUT_HIGH

Configures GPIO pin as output and initializes it to a high state.

GPIO_OUTPUT_INACTIVE

Configures GPIO pin as output and initializes it to a logic 0.

GPIO_OUTPUT_ACTIVE

Configures GPIO pin as output and initializes it to a logic 1.

GPIO interrupt configuration flags

The GPIO_INT_* flags are used to specify how input GPIO pins will trigger interrupts.

The interrupts can be sensitive to pin physical or logical level. Interrupts sensitive to pin logical level take into account GPIO_ACTIVE_LOW flag. If a pin was configured as Active Low, physical level low will be considered as logical level 1 (an active state), physical level high will be considered as logical level 0 (an inactive state). The GPIO controller should reset the interrupt status, such as clearing the pending bit, etc, when configuring the interrupt triggering properties. Applications should use the GPIO_INT_MODE_ENABLE_ONLY and GPIO_INT_MODE_DISABLE_ONLY flags to enable and disable interrupts on the pin without changing any GPIO settings.

GPIO_INT_DISABLE

Disables GPIO pin interrupt.

GPIO_INT_EDGE_RISING

Configures GPIO interrupt to be triggered on pin rising edge and enables it.

GPIO_INT_EDGE_FALLING

Configures GPIO interrupt to be triggered on pin falling edge and enables it.

GPIO_INT_EDGE_BOTH

Configures GPIO interrupt to be triggered on pin rising or falling edge and enables it.

GPIO_INT_LEVEL_LOW

Configures GPIO interrupt to be triggered on pin physical level low and enables it.

GPIO_INT_LEVEL_HIGH

Configures GPIO interrupt to be triggered on pin physical level high and enables it.

GPIO_INT_EDGE_TO_INACTIVE

Configures GPIO interrupt to be triggered on pin state change to logical level 0 and enables it.

GPIO_INT_EDGE_TO_ACTIVE

Configures GPIO interrupt to be triggered on pin state change to logical level 1 and enables it.

GPIO_INT_LEVEL_INACTIVE

Configures GPIO interrupt to be triggered on pin logical level 0 and enables it.

GPIO_INT_LEVEL_ACTIVE

Configures GPIO interrupt to be triggered on pin logical level 1 and enables it.

GPIO pin active level flags

GPIO_ACTIVE_LOW

GPIO pin is active (has logical value ‘1’) in low state.

GPIO_ACTIVE_HIGH

GPIO pin is active (has logical value ‘1’) in high state.

GPIO pin drive flags

GPIO_OPEN_DRAIN

Configures GPIO output in open drain mode (wired AND).

Note

‘Open Drain’ mode also known as ‘Open Collector’ is an output configuration which behaves like a switch that is either connected to ground or disconnected.

GPIO_OPEN_SOURCE

Configures GPIO output in open source mode (wired OR).

Note

‘Open Source’ is a term used by software engineers to describe output mode opposite to ‘Open Drain’. It behaves like a switch that is either connected to power supply or disconnected. There exist no corresponding hardware schematic and the term is generally unknown to hardware engineers.

GPIO pin bias flags

GPIO_PULL_UP

Enables GPIO pin pull-up.

GPIO_PULL_DOWN

Enable GPIO pin pull-down.

Defines

GPIO_DT_SPEC_GET_BY_IDX(node_id, prop, idx)

Static initializer for a gpio_dt_spec.

This returns a static initializer for a gpio_dt_spec structure given a devicetree node identifier, a property specifying a GPIO and an index.

Example devicetree fragment: 

 n: node {
    foo-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>,
                <&gpio1 2 GPIO_ACTIVE_LOW>;
 }
Example usage: 
 const struct gpio_dt_spec spec = GPIO_DT_SPEC_GET_BY_IDX(DT_NODELABEL(n),
                                                     foo_gpios, 1);
 // Initializes 'spec' to:
 // {
 //         .port = DEVICE_DT_GET(DT_NODELABEL(gpio1)),
 //         .pin = 2,
 //         .dt_flags = GPIO_ACTIVE_LOW
 // }
The ‘gpio’ field must still be checked for readiness, e.g. using device_is_ready(). It is an error to use this macro unless the node exists, has the given property, and that property specifies a GPIO controller, pin number, and flags as shown above.

Parameters:

  • node_id – devicetree node identifier

  • prop – lowercase-and-underscores property name

  • idx – logical index into “prop”

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_GET_BY_IDX_OR(node_id, prop, idx, default_value)

Like GPIO_DT_SPEC_GET_BY_IDX(), with a fallback to a default value.

If the devicetree node identifier ‘node_id’ refers to a node with a property ‘prop’, this expands to GPIO_DT_SPEC_GET_BY_IDX(node_id, prop, idx). The default_value parameter is not expanded in this case.

Otherwise, this expands to default_value.

Parameters:

  • node_id – devicetree node identifier

  • prop – lowercase-and-underscores property name

  • idx – logical index into “prop”

  • default_value – fallback value to expand to

Returns:

static initializer for a struct gpio_dt_spec for the property, or default_value if the node or property do not exist

GPIO_DT_SPEC_GET(node_id, prop)

Equivalent to GPIO_DT_SPEC_GET_BY_IDX(node_id, prop, 0).

See also

GPIO_DT_SPEC_GET_BY_IDX()

Parameters:

  • node_id – devicetree node identifier

  • prop – lowercase-and-underscores property name

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_GET_OR(node_id, prop, default_value)

Equivalent to GPIO_DT_SPEC_GET_BY_IDX_OR(node_id, prop, 0, default_value).

See also

GPIO_DT_SPEC_GET_BY_IDX_OR()

Parameters:

  • node_id – devicetree node identifier

  • prop – lowercase-and-underscores property name

  • default_value – fallback value to expand to

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_INST_GET_BY_IDX(inst, prop, idx)

Static initializer for a gpio_dt_spec from a DT_DRV_COMPAT instance’s GPIO property at an index.

See also

GPIO_DT_SPEC_GET_BY_IDX()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • prop – lowercase-and-underscores property name

  • idx – logical index into “prop”

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_INST_GET_BY_IDX_OR(inst, prop, idx, default_value)

Static initializer for a gpio_dt_spec from a DT_DRV_COMPAT instance’s GPIO property at an index, with fallback.

See also

GPIO_DT_SPEC_GET_BY_IDX()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • prop – lowercase-and-underscores property name

  • idx – logical index into “prop”

  • default_value – fallback value to expand to

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_INST_GET(inst, prop)

Equivalent to GPIO_DT_SPEC_INST_GET_BY_IDX(inst, prop, 0).

See also

GPIO_DT_SPEC_INST_GET_BY_IDX()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • prop – lowercase-and-underscores property name

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_SPEC_INST_GET_OR(inst, prop, default_value)

Equivalent to GPIO_DT_SPEC_INST_GET_BY_IDX_OR(inst, prop, 0, default_value).

See also

GPIO_DT_SPEC_INST_GET_BY_IDX()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • prop – lowercase-and-underscores property name

  • default_value – fallback value to expand to

Returns:

static initializer for a struct gpio_dt_spec for the property

GPIO_DT_RESERVED_RANGES_NGPIOS(node_id, ngpios)

Makes a bitmask of reserved GPIOs from DT "gpio-reserved-ranges" property and "ngpios" argument.

This macro returns the value as a bitmask of the "gpio-reserved-ranges" property. This property defines the disabled (or ‘reserved’) GPIOs in the range 0…ngpios-1 and is specified as an array of value’s pairs that define the start offset and size of the reserved ranges.

For example, setting “gpio-reserved-ranges = <3 2>, <10 1>;” means that GPIO offsets 3, 4 and 10 cannot be used even if ngpios = <18>.

The implementation constraint is inherited from common DT limitations: a maximum of 64 pairs can be used (with result limited to bitsize of gpio_port_pins_t type).

NB: Due to the nature of C macros, some incorrect tuple definitions (for example, overlapping or out of range) will produce undefined results.

Also be aware that if ngpios is less than 32 (bit size of DT int type), then all unused MSBs outside the range defined by ngpios will be marked as reserved too.

Example devicetree fragment:

a {
        compatible = "some,gpio-controller";
        ngpios = <32>;
        gpio-reserved-ranges = <0  4>, <5  3>, <9  5>, <11 2>, <15 2>,
                                <18 2>, <21 1>, <23 1>, <25 4>, <30 2>;
};

b {
        compatible = "some,gpio-controller";
        ngpios = <18>;
        gpio-reserved-ranges = <3 2>, <10 1>;
};

Example usage:

struct some_config {
        uint32_t ngpios;
        uint32_t gpios_reserved;
};

static const struct some_config dev_cfg_a = {
        .ngpios = DT_PROP_OR(DT_LABEL(a), ngpios, 0),
        .gpios_reserved = GPIO_DT_RESERVED_RANGES_NGPIOS(DT_LABEL(a),
                                DT_PROP(DT_LABEL(a), ngpios)),
};

static const struct some_config dev_cfg_b = {
        .ngpios = DT_PROP_OR(DT_LABEL(b), ngpios, 0),
        .gpios_reserved = GPIO_DT_RESERVED_RANGES_NGPIOS(DT_LABEL(b),
                                DT_PROP(DT_LABEL(b), ngpios)),
};

This expands to:

struct some_config {
        uint32_t ngpios;
        uint32_t gpios_reserved;
};

static const struct some_config dev_cfg_a = {
        .ngpios = 32,
        .gpios_reserved = 0xdeadbeef,
                       // 0b1101 1110 1010 1101 1011 1110 1110 1111

static const struct some_config dev_cfg_b = {
        .ngpios = 18,
        .gpios_reserved = 0xfffc0418,
                       // 0b1111 1111 1111 1100 0000 0100 0001 1000
                       // unused MSBs were marked as reserved too
};
Parameters:

  • node_id – GPIO controller node identifier.

  • ngpios – number of GPIOs.

Returns:

the bitmask of reserved gpios

GPIO_DT_RESERVED_RANGES(node_id)

Makes a bitmask of reserved GPIOs from the "gpio-reserved-ranges" and "ngpios" DT properties values.

Parameters:

  • node_id – GPIO controller node identifier.

Returns:

the bitmask of reserved gpios

GPIO_DT_INST_RESERVED_RANGES_NGPIOS(inst, ngpios)

Makes a bitmask of reserved GPIOs from a DT_DRV_COMPAT instance’s "gpio-reserved-ranges" property and "ngpios" argument.

See also

GPIO_DT_RESERVED_RANGES()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • ngpios – number of GPIOs

Returns:

the bitmask of reserved gpios

GPIO_DT_INST_RESERVED_RANGES(inst)

Make a bitmask of reserved GPIOs from a DT_DRV_COMPAT instance’s GPIO "gpio-reserved-ranges" and "ngpios" properties.

See also

GPIO_DT_RESERVED_RANGES()

Parameters:

  • inst – DT_DRV_COMPAT instance number

Returns:

the bitmask of reserved gpios

GPIO_DT_PORT_PIN_MASK_NGPIOS_EXC(node_id, ngpios)

Makes a bitmask of allowed GPIOs from DT "gpio-reserved-ranges" property and "ngpios" argument.

This macro is paired with GPIO_DT_RESERVED_RANGES_NGPIOS(), however unlike the latter, it returns a bitmask of ALLOWED gpios.

Example devicetree fragment:

a {
   compatible = "some,gpio-controller";
   ngpios = <32>;
   gpio-reserved-ranges = <0 8>, <9 5>, <15 16>;
};

Example usage:

struct some_config {
   uint32_t port_pin_mask;
};

static const struct some_config dev_cfg = {
   .port_pin_mask = GPIO_DT_PORT_PIN_MASK_NGPIOS_EXC(
                           DT_LABEL(a), 32),
};

This expands to:

struct some_config {
   uint32_t port_pin_mask;
};

static const struct some_config dev_cfg = {
   .port_pin_mask = 0x80004100,
                   // 0b1000 0000 0000 0000 0100 0001 00000 000
};
Parameters:

  • node_id – GPIO controller node identifier.

  • ngpios – number of GPIOs

Returns:

the bitmask of allowed gpios

GPIO_DT_INST_PORT_PIN_MASK_NGPIOS_EXC(inst, ngpios)

Makes a bitmask of allowed GPIOs from a DT_DRV_COMPAT instance’s "gpio-reserved-ranges" property and "ngpios" argument.

See also

GPIO_DT_NGPIOS_PORT_PIN_MASK_EXC()

Parameters:

  • inst – DT_DRV_COMPAT instance number

  • ngpios – number of GPIOs

Returns:

the bitmask of allowed gpios

GPIO_MAX_PINS_PER_PORT

Maximum number of pins that are supported by gpio_port_pins_t.

GPIO_DT_FLAGS_MASK

Mask for DT GPIO flags.

GPIO_INT_WAKEUP

Configures GPIO interrupt to wakeup the system from low power mode.

Typedefs

typedef uint32_t gpio_port_pins_t

Identifies a set of pins associated with a port.

The pin with index n is present in the set if and only if the bit identified by (1U << n) is set.

typedef uint32_t gpio_port_value_t

Provides values for a set of pins associated with a port.

The value for a pin with index n is high (physical mode) or active (logical mode) if and only if the bit identified by (1U << n) is set. Otherwise the value for the pin is low (physical mode) or inactive (logical mode).

Values of this type are often paired with a gpio_port_pins_t value that specifies which encoded pin values are valid for the operation.

typedef uint8_t gpio_pin_t

Provides a type to hold a GPIO pin index.

This reduced-size type is sufficient to record a pin number, e.g. from a devicetree GPIOS property.

typedef uint16_t gpio_dt_flags_t

Provides a type to hold GPIO devicetree flags.

All GPIO flags that can be expressed in devicetree fit in the low 16 bits of the full flags field, so use a reduced-size type to record that part of a GPIOS property.

The lower 8 bits are used for standard flags. The upper 8 bits are reserved for SoC specific flags.

typedef uint32_t gpio_flags_t

Provides a type to hold GPIO configuration flags.

This type is sufficient to hold all flags used to control GPIO configuration, whether pin or interrupt.

typedef void (*gpio_callback_handler_t)(const struct device *port, struct gpio_callback *cb, gpio_port_pins_t pins)

Define the application callback handler function signature.

Note: cb pointer can be used to retrieve private data through CONTAINER_OF() if original struct gpio_callback is stored in another private structure.

Param port:

Device struct for the GPIO device.

Param cb:

Original struct gpio_callback owning this handler

Param pins:

Mask of pins that triggers the callback handler

Functions

static inline bool gpio_is_ready_dt(const struct gpio_dt_spec *spec)

Validate that GPIO port is ready.

Parameters:

  • spec – GPIO specification from devicetree

Return values:

  • true – if the GPIO spec is ready for use.

  • false – if the GPIO spec is not ready for use.

int gpio_pin_interrupt_configure(const struct device *port, gpio_pin_t pin, gpio_flags_t flags)

Configure pin interrupt.

Note

This function can also be used to configure interrupts on pins not controlled directly by the GPIO module. That is, pins which are routed to other modules such as I2C, SPI, UART.

Parameters:

  • port – Pointer to device structure for the driver instance.

  • pin – Pin number.

  • flags – Interrupt configuration flags as defined by GPIO_INT_*.

Return values:

  • 0 – If successful.

  • -ENOSYS – If the operation is not implemented by the driver.

  • -ENOTSUP – If any of the configuration options is not supported (unless otherwise directed by flag documentation).

  • -EINVAL – Invalid argument.

  • -EBUSY – Interrupt line required to configure pin interrupt is already in use.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_interrupt_configure_dt(const struct gpio_dt_spec *spec, gpio_flags_t flags)

Configure pin interrupts from a gpio_dt_spec.

This is equivalent to: 

gpio_pin_interrupt_configure(spec->port, spec->pin, flags);
The spec->dt_flags value is not used.

Parameters:

  • spec – GPIO specification from devicetree

  • flags – interrupt configuration flags

Returns:

a value from gpio_pin_interrupt_configure()

int gpio_pin_configure(const struct device *port, gpio_pin_t pin, gpio_flags_t flags)

Configure a single pin.

Parameters:

  • port – Pointer to device structure for the driver instance.

  • pin – Pin number to configure.

  • flags – Flags for pin configuration: ‘GPIO input/output configuration flags’, ‘GPIO pin drive flags’, ‘GPIO pin bias flags’.

Return values:

  • 0 – If successful.

  • -ENOTSUP – if any of the configuration options is not supported (unless otherwise directed by flag documentation).

  • -EINVAL – Invalid argument.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_configure_dt(const struct gpio_dt_spec *spec, gpio_flags_t extra_flags)

Configure a single pin from a gpio_dt_spec and some extra flags.

This is equivalent to: 

gpio_pin_configure(spec->port, spec->pin, spec->dt_flags | extra_flags);

Parameters:

  • spec – GPIO specification from devicetree

  • extra_flags – additional flags

Returns:

a value from gpio_pin_configure()

int gpio_port_get_direction(const struct device *port, gpio_port_pins_t map, gpio_port_pins_t *inputs, gpio_port_pins_t *outputs)

Get direction of select pins in a port.

Retrieve direction of each pin specified in map.

If inputs or outputs is NULL, then this function does not get the respective input or output direction information.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • map – Bitmap of pin directions to query.

  • inputs – Pointer to a variable where input directions will be stored.

  • outputs – Pointer to a variable where output directions will be stored.

Return values:

  • 0 – If successful.

  • -ENOSYS – if the underlying driver does not support this call.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_is_input(const struct device *port, gpio_pin_t pin)

Check if pin is configured for input.

Parameters:

  • port – Pointer to device structure for the driver instance.

  • pin – Pin number to query the direction of

Return values:

  • 1 – if pin is configured as GPIO_INPUT.

  • 0 – if pin is not configured as GPIO_INPUT.

  • -ENOSYS – if the underlying driver does not support this call.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_is_input_dt(const struct gpio_dt_spec *spec)

Check if a single pin from gpio_dt_spec is configured for input.

This is equivalent to: 

gpio_pin_is_input(spec->port, spec->pin);

Parameters:

  • spec – GPIO specification from devicetree.

Returns:

A value from gpio_pin_is_input().

static inline int gpio_pin_is_output(const struct device *port, gpio_pin_t pin)

Check if pin is configured for output.

Parameters:

  • port – Pointer to device structure for the driver instance.

  • pin – Pin number to query the direction of

Return values:

  • 1 – if pin is configured as GPIO_OUTPUT.

  • 0 – if pin is not configured as GPIO_OUTPUT.

  • -ENOSYS – if the underlying driver does not support this call.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_is_output_dt(const struct gpio_dt_spec *spec)

Check if a single pin from gpio_dt_spec is configured for output.

This is equivalent to: 

gpio_pin_is_output(spec->port, spec->pin);

Parameters:

  • spec – GPIO specification from devicetree.

Returns:

A value from gpio_pin_is_output().

int gpio_pin_get_config(const struct device *port, gpio_pin_t pin, gpio_flags_t *flags)

Get a configuration of a single pin.

Parameters:

  • port – Pointer to device structure for the driver instance.

  • pin – Pin number which configuration is get.

  • flags – Pointer to variable in which the current configuration will be stored if function is successful.

Return values:

  • 0 – If successful.

  • -ENOSYS – if getting current pin configuration is not implemented by the driver.

  • -EINVAL – Invalid argument.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_get_config_dt(const struct gpio_dt_spec *spec, gpio_flags_t *flags)

Get a configuration of a single pin from a gpio_dt_spec.

This is equivalent to: 

gpio_pin_get_config(spec->port, spec->pin, flags);

Parameters:

  • spec – GPIO specification from devicetree

  • flags – Pointer to variable in which the current configuration will be stored if function is successful.

Returns:

a value from gpio_pin_configure()

int gpio_port_get_raw(const struct device *port, gpio_port_value_t *value)

Get physical level of all input pins in a port.

A low physical level on the pin will be interpreted as value 0. A high physical level will be interpreted as value 1. This function ignores GPIO_ACTIVE_LOW flag.

Value of a pin with index n will be represented by bit n in the returned port value.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • value – Pointer to a variable where pin values will be stored.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_get(const struct device *port, gpio_port_value_t *value)

Get logical level of all input pins in a port.

Get logical level of an input pin taking into account GPIO_ACTIVE_LOW flag. If pin is configured as Active High, a low physical level will be interpreted as logical value 0. If pin is configured as Active Low, a low physical level will be interpreted as logical value 1.

Value of a pin with index n will be represented by bit n in the returned port value.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • value – Pointer to a variable where pin values will be stored.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

int gpio_port_set_masked_raw(const struct device *port, gpio_port_pins_t mask, gpio_port_value_t value)

Set physical level of output pins in a port.

Writing value 0 to the pin will set it to a low physical level. Writing value 1 will set it to a high physical level. This function ignores GPIO_ACTIVE_LOW flag.

Pin with index n is represented by bit n in mask and value parameter.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • mask – Mask indicating which pins will be modified.

  • value – Value assigned to the output pins.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_set_masked(const struct device *port, gpio_port_pins_t mask, gpio_port_value_t value)

Set logical level of output pins in a port.

Set logical level of an output pin taking into account GPIO_ACTIVE_LOW flag. Value 0 sets the pin in logical 0 / inactive state. Value 1 sets the pin in logical 1 / active state. If pin is configured as Active High, the default, setting it in inactive state will force the pin to a low physical level. If pin is configured as Active Low, setting it in inactive state will force the pin to a high physical level.

Pin with index n is represented by bit n in mask and value parameter.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • mask – Mask indicating which pins will be modified.

  • value – Value assigned to the output pins.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

int gpio_port_set_bits_raw(const struct device *port, gpio_port_pins_t pins)

Set physical level of selected output pins to high.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pins – Value indicating which pins will be modified.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_set_bits(const struct device *port, gpio_port_pins_t pins)

Set logical level of selected output pins to active.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pins – Value indicating which pins will be modified.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

int gpio_port_clear_bits_raw(const struct device *port, gpio_port_pins_t pins)

Set physical level of selected output pins to low.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pins – Value indicating which pins will be modified.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_clear_bits(const struct device *port, gpio_port_pins_t pins)

Set logical level of selected output pins to inactive.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pins – Value indicating which pins will be modified.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

int gpio_port_toggle_bits(const struct device *port, gpio_port_pins_t pins)

Toggle level of selected output pins.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pins – Value indicating which pins will be modified.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_set_clr_bits_raw(const struct device *port, gpio_port_pins_t set_pins, gpio_port_pins_t clear_pins)

Set physical level of selected output pins.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • set_pins – Value indicating which pins will be set to high.

  • clear_pins – Value indicating which pins will be set to low.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_port_set_clr_bits(const struct device *port, gpio_port_pins_t set_pins, gpio_port_pins_t clear_pins)

Set logical level of selected output pins.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • set_pins – Value indicating which pins will be set to active.

  • clear_pins – Value indicating which pins will be set to inactive.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_get_raw(const struct device *port, gpio_pin_t pin)

Get physical level of an input pin.

A low physical level on the pin will be interpreted as value 0. A high physical level will be interpreted as value 1. This function ignores GPIO_ACTIVE_LOW flag.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pin – Pin number.

Return values:

  • 1 – If pin physical level is high.

  • 0 – If pin physical level is low.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_get(const struct device *port, gpio_pin_t pin)

Get logical level of an input pin.

Get logical level of an input pin taking into account GPIO_ACTIVE_LOW flag. If pin is configured as Active High, a low physical level will be interpreted as logical value 0. If pin is configured as Active Low, a low physical level will be interpreted as logical value 1.

Note: If pin is configured as Active High, the default, gpio_pin_get() function is equivalent to gpio_pin_get_raw().

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pin – Pin number.

Return values:

  • 1 – If pin logical value is 1 / active.

  • 0 – If pin logical value is 0 / inactive.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_get_dt(const struct gpio_dt_spec *spec)

Get logical level of an input pin from a gpio_dt_spec.

This is equivalent to: 

gpio_pin_get(spec->port, spec->pin);

Parameters:

  • spec – GPIO specification from devicetree

Returns:

a value from gpio_pin_get()

static inline int gpio_pin_set_raw(const struct device *port, gpio_pin_t pin, int value)

Set physical level of an output pin.

Writing value 0 to the pin will set it to a low physical level. Writing any value other than 0 will set it to a high physical level. This function ignores GPIO_ACTIVE_LOW flag.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pin – Pin number.

  • value – Value assigned to the pin.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_set(const struct device *port, gpio_pin_t pin, int value)

Set logical level of an output pin.

Set logical level of an output pin taking into account GPIO_ACTIVE_LOW flag. Value 0 sets the pin in logical 0 / inactive state. Any value other than 0 sets the pin in logical 1 / active state. If pin is configured as Active High, the default, setting it in inactive state will force the pin to a low physical level. If pin is configured as Active Low, setting it in inactive state will force the pin to a high physical level.

Note: If pin is configured as Active High, gpio_pin_set() function is equivalent to gpio_pin_set_raw().

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pin – Pin number.

  • value – Value assigned to the pin.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_set_dt(const struct gpio_dt_spec *spec, int value)

Set logical level of a output pin from a gpio_dt_spec.

This is equivalent to: 

gpio_pin_set(spec->port, spec->pin, value);

Parameters:

  • spec – GPIO specification from devicetree

  • value – Value assigned to the pin.

Returns:

a value from gpio_pin_set()

static inline int gpio_pin_toggle(const struct device *port, gpio_pin_t pin)

Toggle pin level.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • pin – Pin number.

Return values:

  • 0 – If successful.

  • -EIO – I/O error when accessing an external GPIO chip.

  • -EWOULDBLOCK – if operation would block.

static inline int gpio_pin_toggle_dt(const struct gpio_dt_spec *spec)

Toggle pin level from a gpio_dt_spec.

This is equivalent to: 

gpio_pin_toggle(spec->port, spec->pin);

Parameters:

  • spec – GPIO specification from devicetree

Returns:

a value from gpio_pin_toggle()

static inline void gpio_init_callback(struct gpio_callback *callback, gpio_callback_handler_t handler, gpio_port_pins_t pin_mask)

Helper to initialize a struct gpio_callback properly.

Parameters:

  • callback – A valid Application’s callback structure pointer.

  • handler – A valid handler function pointer.

  • pin_mask – A bit mask of relevant pins for the handler

static inline int gpio_add_callback(const struct device *port, struct gpio_callback *callback)

Add an application callback.

Note: enables to add as many callback as needed on the same port.

Note

Callbacks may be added to the device from within a callback handler invocation, but whether they are invoked for the current GPIO event is not specified.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • callback – A valid Application’s callback structure pointer.

Return values:

  • 0 – If successful

  • -ENOSYS – If driver does not implement the operation

  • -errno – Other negative errno code on failure.

static inline int gpio_add_callback_dt(const struct gpio_dt_spec *spec, struct gpio_callback *callback)

Add an application callback.

This is equivalent to: 

gpio_add_callback(spec->port, callback);

Parameters:

  • spec – GPIO specification from devicetree.

  • callback – A valid application’s callback structure pointer.

Returns:

a value from gpio_add_callback().

static inline int gpio_remove_callback(const struct device *port, struct gpio_callback *callback)

Remove an application callback.

Note: enables to remove as many callbacks as added through gpio_add_callback().

Warning

It is explicitly permitted, within a callback handler, to remove the registration for the callback that is running, i.e. callback. Attempts to remove other registrations on the same device may result in undefined behavior, including failure to invoke callbacks that remain registered and unintended invocation of removed callbacks.

Parameters:

  • port – Pointer to the device structure for the driver instance.

  • callback – A valid application’s callback structure pointer.

Return values:

  • 0 – If successful

  • -ENOSYS – If driver does not implement the operation

  • -errno – Other negative errno code on failure.

static inline int gpio_remove_callback_dt(const struct gpio_dt_spec *spec, struct gpio_callback *callback)

Remove an application callback.

This is equivalent to: 

gpio_remove_callback(spec->port, callback);

Parameters:

  • spec – GPIO specification from devicetree.

  • callback – A valid application’s callback structure pointer.

Returns:

a value from gpio_remove_callback().

int gpio_get_pending_int(const struct device *dev)

Function to get pending interrupts.

The purpose of this function is to return the interrupt status register for the device. This is especially useful when waking up from low power states to check the wake up source.

Parameters:

  • dev – Pointer to the device structure for the driver instance.

Return values:

  • status – != 0 if at least one gpio interrupt is pending.

  • 0 – if no gpio interrupt is pending.

  • -ENOSYS – If driver does not implement the operation

struct gpio_dt_spec
#include <gpio.h>

Container for GPIO pin information specified in devicetree.

This type contains a pointer to a GPIO device, pin number for a pin controlled by that device, and the subset of pin configuration flags which may be given in devicetree.

See also

GPIO_DT_SPEC_GET_BY_IDX

See also

GPIO_DT_SPEC_GET_BY_IDX_OR

See also

GPIO_DT_SPEC_GET

See also

GPIO_DT_SPEC_GET_OR

Public Members

const struct device *port

GPIO device controlling the pin.

gpio_pin_t pin

The pin’s number on the device.

gpio_dt_flags_t dt_flags

The pin’s configuration flags as specified in devicetree.

struct gpio_driver_config
#include <gpio.h>

This structure is common to all GPIO drivers and is expected to be the first element in the object pointed to by the config field in the device structure.

Public Members

gpio_port_pins_t port_pin_mask

Mask identifying pins supported by the controller.

Initialization of this mask is the responsibility of device instance generation in the driver.

struct gpio_driver_data
#include <gpio.h>

This structure is common to all GPIO drivers and is expected to be the first element in the driver’s struct driver_data declaration.

Public Members

gpio_port_pins_t invert

Mask identifying pins that are configured as active low.

Management of this mask is the responsibility of the wrapper functions in this header.

struct gpio_callback
#include <gpio.h>

GPIO callback structure.

Used to register a callback in the driver instance callback list. As many callbacks as needed can be added as long as each of them are unique pointers of struct gpio_callback. Beware such structure should not be allocated on stack.

Note: To help setting it, see gpio_init_callback() below

Public Members

sys_snode_t node

This is meant to be used in the driver and the user should not mess with it (see drivers/gpio/gpio_utils.h)

gpio_callback_handler_t handler

Actual callback function being called when relevant.

gpio_port_pins_t pin_mask

A mask of pins the callback is interested in, if 0 the callback will never be called.

Such pin_mask can be modified whenever necessary by the owner, and thus will affect the handler being called or not. The selected pins must be configured to trigger an interrupt.