[PATCH 1/2] RTEMS GPIO API definition and implementation.
Andre Marques
andre.lousa.marques at gmail.com
Mon Jun 22 12:01:01 UTC 2015
---
c/src/lib/libbsp/Makefile.am | 3 +-
c/src/lib/libbsp/preinstall.am | 4 +
c/src/lib/libbsp/shared/gpio.c | 1083 ++++++++++++++++++++++++++++++++
c/src/lib/libbsp/shared/include/gpio.h | 610 ++++++++++++++++++
4 files changed, 1699 insertions(+), 1 deletion(-)
create mode 100644 c/src/lib/libbsp/shared/gpio.c
create mode 100644 c/src/lib/libbsp/shared/include/gpio.h
diff --git a/c/src/lib/libbsp/Makefile.am b/c/src/lib/libbsp/Makefile.am
index 3cab4d7..a039a98 100644
--- a/c/src/lib/libbsp/Makefile.am
+++ b/c/src/lib/libbsp/Makefile.am
@@ -9,7 +9,7 @@ EXTRA_DIST = MERGE.PROCEDURE bsp.am
EXTRA_DIST += shared/bootcard.c shared/bspclean.c \
shared/bsplibc.c shared/bsppost.c shared/console-polled.c \
shared/console.c shared/gnatinstallhandler.c shared/sbrk.c \
- shared/tod.c
+ shared/tod.c shared/gpio.c
EXTRA_DIST += shared/vmeUniverse/vmeUniverse.c \
shared/vmeUniverse/vmeUniverse.h \
shared/vmeUniverse/vmeUniverseDMA.h \
@@ -35,6 +35,7 @@ include_bsp_HEADERS =
include_bsp_HEADERS += shared/include/default-initial-extension.h
include_bsp_HEADERS += shared/include/fatal.h
include_bsp_HEADERS += shared/include/console-termios.h
+include_bsp_HEADERS += shared/include/gpio.h
include $(srcdir)/preinstall.am
include $(top_srcdir)/automake/subdirs.am
diff --git a/c/src/lib/libbsp/preinstall.am b/c/src/lib/libbsp/preinstall.am
index 651f136..bbcb7c5 100644
--- a/c/src/lib/libbsp/preinstall.am
+++ b/c/src/lib/libbsp/preinstall.am
@@ -30,3 +30,7 @@ $(PROJECT_INCLUDE)/bsp/console-termios.h: shared/include/console-termios.h $(PRO
$(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/console-termios.h
PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/console-termios.h
+$(PROJECT_INCLUDE)/bsp/gpio.h: shared/include/gpio.h $(PROJECT_INCLUDE)/bsp/$(dirstamp)
+ $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/gpio.h
+PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/gpio.h
+
diff --git a/c/src/lib/libbsp/shared/gpio.c b/c/src/lib/libbsp/shared/gpio.c
new file mode 100644
index 0000000..12cdb29
--- /dev/null
+++ b/c/src/lib/libbsp/shared/gpio.c
@@ -0,0 +1,1083 @@
+/**
+ * @file gpio.c
+ *
+ * @ingroup rtems_gpio
+ *
+ * @brief RTEMS GPIO API implementation.
+ */
+
+/*
+ * Copyright (c) 2014-2015 Andre Marques <andre.lousa.marques at gmail.com>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#include <rtems/score/atomic.h>
+#include <rtems/status-checks.h>
+#include <bsp/irq-generic.h>
+#include <bsp/gpio.h>
+
+#include <assert.h>
+#include <stdlib.h>
+
+/**
+ * @brief GPIO API mutex atributes.
+ */
+#define MUTEX_ATRIBUTES \
+ ( RTEMS_LOCAL \
+ | RTEMS_PRIORITY \
+ | RTEMS_BINARY_SEMAPHORE \
+ | RTEMS_INHERIT_PRIORITY \
+ | RTEMS_NO_PRIORITY_CEILING \
+ )
+
+#define AQUIRE_LOCK(m) assert( rtems_semaphore_obtain(m, \
+ RTEMS_WAIT, \
+ RTEMS_NO_TIMEOUT \
+ ) == RTEMS_SUCCESSFUL )
+
+#define RELEASE_LOCK(m) assert( rtems_semaphore_release(m) == RTEMS_SUCCESSFUL )
+
+/*Encapsulates relevant data for a GPIO interrupt handler. */
+typedef struct _gpio_handler_list
+{
+ struct _gpio_handler_list *next_isr;
+
+ /* User-defined ISR routine. */
+ rtems_gpio_irq_state (*handler) (void *arg);
+
+ /* User-defined arguments for the ISR routine. */
+ void *arg;
+} gpio_handler_list;
+
+/* Encapsulates relevant data about a GPIO pin. */
+typedef struct
+{
+ uint32_t bank_number;
+ uint32_t pin_number;
+
+ rtems_gpio_function pin_function;
+
+ /* Type of event which will trigger an interrupt. */
+ rtems_gpio_interrupt enabled_interrupt;
+
+ /* Id of the task that will be calling the user-defined ISR handlers
+ * for this pin. */
+ rtems_id task_id;
+
+ /* ISR shared flag. */
+ rtems_gpio_handler_flag handler_flag;
+
+ /* Linked list of interrupt handlers. */
+ gpio_handler_list *handler_list;
+
+ /* GPIO input (pull resistor) pin mode. */
+ rtems_gpio_pull_mode resistor_mode;
+
+ /* If true inverts digital in/out logic. */
+ int logic_invert;
+
+ /* Switch-deboucing information. */
+ int debouncing_tick_count;
+ rtems_interval last_isr_tick;
+} gpio_pin;
+
+static gpio_pin** gpio_pin_state;
+static Atomic_Flag init_flag = ATOMIC_INITIALIZER_FLAG;
+static uint32_t gpio_count;
+static uint32_t bank_count;
+static uint32_t pins_per_bank;
+static uint32_t odd_bank_pins;
+static uint32_t* interrupt_counter;
+static rtems_id* bank_lock;
+
+#define BANK_NUMBER(pin_number) pin_number / pins_per_bank
+#define PIN_NUMBER(pin_number) pin_number % pins_per_bank
+
+static int debounce_switch(gpio_pin* gpio)
+{
+ rtems_interval time;
+
+ time = rtems_clock_get_ticks_since_boot();
+
+ /* If not enough time has elapsed since last interrupt. */
+ if ( (time - gpio->last_isr_tick) < gpio->debouncing_tick_count ) {
+ return -1;
+ }
+
+ gpio->last_isr_tick = time;
+
+ return 0;
+}
+
+static rtems_task generic_handler_task(rtems_task_argument arg)
+{
+ gpio_handler_list *handler_list;
+ rtems_event_set out;
+ gpio_pin* gpio;
+ uint32_t bank;
+ int handled_count;
+ int rv;
+
+ gpio = (gpio_pin*) arg;
+
+ bank = gpio->bank_number;
+
+ while ( true ) {
+ handled_count = 0;
+
+ /* Wait for interrupt event. This is sent by the bank's generic_isr handler. */
+ rtems_event_receive(RTEMS_EVENT_1, RTEMS_EVENT_ALL | RTEMS_WAIT,
+ RTEMS_NO_TIMEOUT,
+ &out);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ /* If this pin has the debouncing function attached, call it. */
+ if ( gpio->debouncing_tick_count > 0 ) {
+ rv = debounce_switch(gpio);
+
+ /* If the handler call was caused by a switch bounce, ignores and move on. */
+ if ( rv < 0 ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ continue;
+ }
+
+ /* Record the current clock tick. */
+ gpio->last_isr_tick = rtems_clock_get_ticks_since_boot();
+ }
+
+ handler_list = gpio->handler_list;
+
+ /* Iterate the ISR list. */
+ while ( handler_list != NULL ) {
+ if ( (handler_list->handler)(handler_list->arg) == IRQ_HANDLED ) {
+ ++handled_count;
+ }
+
+ handler_list = handler_list->next_isr;
+ }
+
+ /* If no handler assumed the interrupt, treat it as a spurious interrupt. */
+ if ( handled_count == 0 ) {
+ bsp_interrupt_handler_default(rtems_bsp_gpio_get_vector(bank));
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+ }
+}
+
+static void generic_isr(void* arg)
+{
+ rtems_vector_number vector;
+ uint32_t event_status;
+ uint32_t bank_pin_count;
+ gpio_pin *gpio;
+ uint32_t bank_number;
+ int i;
+
+ gpio = (gpio_pin *) arg;
+
+ /* Get the bank/vector number of a pin (e.g.: 0) from this bank. */
+ bank_number = gpio[0].bank_number;
+
+ vector = rtems_bsp_gpio_get_vector(bank_number);
+
+ /* If the current bank is an odd last bank (i.e.: not completely filled). */
+ if ( odd_bank_pins > 0 && bank_number == bank_count - 1 ) {
+ bank_pin_count = odd_bank_pins;
+ }
+ else {
+ bank_pin_count = pins_per_bank;
+ }
+
+ /* Prevents more interrupts from being generated on GPIO. */
+ bsp_interrupt_vector_disable(vector);
+
+ /* Ensure that interrupts are disabled in this vector, before checking
+ * the interrupt line. */
+ RTEMS_COMPILER_MEMORY_BARRIER();
+
+ /* Obtains a 32-bit bitmask, with the pins currently reporting interrupts
+ * signaled with 1. */
+ event_status = rtems_bsp_gpio_interrupt_line(vector);
+
+ /* Iterates through the bitmask and calls the corresponding handler
+ * for active interrupts. */
+ for ( i = 0; i < bank_pin_count; ++i ) {
+ /* If active, wake the corresponding pin's ISR task. */
+ if ( event_status & (1 << i) ) {
+ rtems_event_send(gpio[i].task_id, RTEMS_EVENT_1);
+ }
+ }
+
+ /* Clear all active events. */
+ rtems_bsp_gpio_clear_interrupt_line(vector, event_status);
+
+ /* Ensure that the interrupt line is cleared before re-activating
+ * the interrupts on this vector. */
+ RTEMS_COMPILER_MEMORY_BARRIER();
+
+ bsp_interrupt_vector_enable(vector);
+}
+
+static uint32_t get_pin_bitmask(uint32_t count, va_list args, uint32_t* bank_number, rtems_status_code* sc)
+{
+ uint32_t bank;
+ uint32_t pin;
+ uint32_t bitmask;
+ uint32_t pin_number;
+ int i;
+
+ if ( count < 1 ) {
+ *sc = RTEMS_UNSATISFIED;
+
+ return 0;
+ }
+
+ bitmask = 0;
+
+ for ( i = 0; i < count; ++i ) {
+ pin_number = va_arg(args, uint32_t);
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ *sc = RTEMS_INVALID_ID;
+
+ return 0;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ if ( i == 0 ) {
+ *bank_number = bank;
+
+ AQUIRE_LOCK(bank_lock[bank]);
+ }
+ else if ( bank != *bank_number ) {
+ *sc = RTEMS_UNSATISFIED;
+
+ RELEASE_LOCK(bank_lock[*bank_number]);
+
+ return 0;
+ }
+
+ if ( gpio_pin_state[bank][pin].pin_function != DIGITAL_OUTPUT ) {
+ *sc = RTEMS_NOT_CONFIGURED;
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return 0;
+ }
+
+ bitmask |= (1 << PIN_NUMBER(pin_number));
+ }
+
+ *sc = RTEMS_SUCCESSFUL;
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return bitmask;
+}
+
+rtems_status_code rtems_gpio_initialize(void)
+{
+ rtems_status_code sc;
+ rtems_gpio_layout layout;
+ int bank_pins;
+ int pin;
+ int bank;
+ int i;
+
+ if ( _Atomic_Flag_test_and_set(&init_flag, ATOMIC_ORDER_RELAXED) == true ) {
+ return RTEMS_SUCCESSFUL;
+ }
+
+ layout = rtems_bsp_gpio_initialize();
+
+ gpio_count = layout.pin_count;
+ pins_per_bank = layout.pins_per_bank;
+
+ bank_count = gpio_count / pins_per_bank;
+
+ /* Account for remaining pins after filling the last bank. */
+ odd_bank_pins = gpio_count % pins_per_bank;
+
+ if ( odd_bank_pins > 0 ) {
+ ++bank_count;
+ }
+
+ /* Create GPIO bank mutexes. */
+ bank_lock = (rtems_id*) malloc(bank_count * sizeof(rtems_id));
+
+ for ( i = 0; i < bank_count; ++i ) {
+ sc = rtems_semaphore_create(rtems_build_name('G', 'I', 'N', 'T'), 1, MUTEX_ATRIBUTES, 0, &bank_lock[i]);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ return sc;
+ }
+ }
+
+ /* Create GPIO pin state matrix. */
+ gpio_pin_state = (gpio_pin**) malloc(bank_count * sizeof(gpio_pin*));
+
+ for ( i = 0; i < bank_count; ++i ) {
+ if ( i == bank_count - 1 ) {
+ bank_pins = odd_bank_pins;
+ }
+ else {
+ bank_pins = pins_per_bank;
+ }
+
+ gpio_pin_state[i] = (gpio_pin*) malloc(bank_pins * sizeof(gpio_pin));
+ }
+
+ /* Creates an interrupt counter per pin bank. */
+ interrupt_counter = (uint32_t*) calloc(bank_count, sizeof(uint32_t));
+
+ for ( i = 0; i < gpio_count; ++i ) {
+ bank = BANK_NUMBER(i);
+ pin = PIN_NUMBER(i);
+
+ gpio_pin_state[bank][pin].bank_number = bank;
+ gpio_pin_state[bank][pin].pin_number = pin;
+ gpio_pin_state[bank][pin].pin_function = NOT_USED;
+ gpio_pin_state[bank][pin].enabled_interrupt = NONE;
+ gpio_pin_state[bank][pin].task_id = RTEMS_ID_NONE;
+ gpio_pin_state[bank][pin].handler_list = NULL;
+ gpio_pin_state[bank][pin].debouncing_tick_count = 0;
+ gpio_pin_state[bank][pin].last_isr_tick = 0;
+ }
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_request_conf(rtems_gpio_pin_conf* conf)
+{
+ rtems_gpio_interrupt_conf* interrupt_conf;
+ rtems_status_code sc;
+ bool new_request;
+ uint32_t bank;
+ uint32_t pin;
+
+ new_request = false;
+
+ sc = rtems_gpio_request_pin(conf->pin_number, conf->function, conf->output_enabled, conf->logic_invert, conf->bsp_specific);
+
+ if ( sc == RTEMS_SUCCESSFUL ) {
+ new_request = true;
+ }
+ /* If the pin is being used, then this function call is an update call.
+ * If not, an error occurred. */
+ else if ( sc != RTEMS_RESOURCE_IN_USE ) {
+ RTEMS_SYSLOG_ERROR("rtems_gpio_request_pin failed with status code %d\n", sc);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ sc = rtems_gpio_resistor_mode(conf->pin_number, conf->pull_mode);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RTEMS_SYSLOG_ERROR("rtems_gpio_resistor_mode failed with status code %d\n", sc);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ interrupt_conf = (rtems_gpio_interrupt_conf*) conf->interrupt;
+
+ if ( interrupt_conf != NULL ) {
+ bank = BANK_NUMBER(conf->pin_number);
+ pin = PIN_NUMBER(conf->pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ if ( interrupt_conf->enabled_interrupt != gpio_pin_state[bank][pin].enabled_interrupt ) {
+ if ( new_request == false ) {
+ sc = rtems_gpio_disable_interrupt(conf->pin_number);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ RTEMS_SYSLOG_ERROR("rtems_gpio_disable_interrupt failed with status code %d\n", sc);
+
+ return RTEMS_UNSATISFIED;
+ }
+ }
+
+ sc = rtems_gpio_enable_interrupt(conf->pin_number,
+ interrupt_conf->enabled_interrupt,
+ interrupt_conf->handler_flag,
+ interrupt_conf->handler,
+ interrupt_conf->arg);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ RTEMS_SYSLOG_ERROR("rtems_gpio_enable_interrupt failed with status code %d\n", sc);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ }
+
+ if ( interrupt_conf->clock_tick_interval != gpio_pin_state[bank][pin].debouncing_tick_count ) {
+ gpio_pin_state[bank][pin].debouncing_tick_count = interrupt_conf->clock_tick_interval;
+ gpio_pin_state[bank][pin].last_isr_tick = 0;
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+ }
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_multi_set(uint32_t count, ...)
+{
+ rtems_status_code sc;
+ uint32_t bank;
+ uint32_t bitmask;
+ va_list ap;
+
+ va_start(ap, count);
+
+ bitmask = get_pin_bitmask(count, ap, &bank, &sc);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RTEMS_SYSLOG_ERROR("error parsing function arguments\n");
+
+ return sc;
+ }
+
+ va_end(ap);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ sc = rtems_bsp_gpio_multi_set(bank, bitmask);
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+}
+
+rtems_status_code rtems_gpio_multi_clear(uint32_t count, ...)
+{
+ rtems_status_code sc;
+ uint32_t bank;
+ uint32_t bitmask;
+ va_list ap;
+
+ va_start(ap, count);
+
+ bitmask = get_pin_bitmask(count, ap, &bank, &sc);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RTEMS_SYSLOG_ERROR("error parsing function arguments\n");
+
+ return sc;
+ }
+
+ va_end(ap);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ sc = rtems_bsp_gpio_multi_clear(bank, bitmask);
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+}
+
+rtems_status_code rtems_gpio_set(uint32_t pin_number)
+{
+ rtems_status_code sc;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ if ( gpio_pin_state[bank][pin].pin_function != DIGITAL_OUTPUT ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ RTEMS_SYSLOG_ERROR("Can only set digital output pins\n");
+
+ return RTEMS_NOT_CONFIGURED;
+ }
+
+ if ( gpio_pin_state[bank][pin].logic_invert ) {
+ sc = rtems_bsp_gpio_clear(bank, pin);
+ }
+ else {
+ sc = rtems_bsp_gpio_set(bank, pin);
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+}
+
+rtems_status_code rtems_gpio_clear(uint32_t pin_number)
+{
+ rtems_status_code sc;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ if ( gpio_pin_state[bank][pin].pin_function != DIGITAL_OUTPUT ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ RTEMS_SYSLOG_ERROR("Can only clear digital output pins\n");
+
+ return RTEMS_NOT_CONFIGURED;
+ }
+
+ if ( gpio_pin_state[bank][pin].logic_invert ) {
+ sc = rtems_bsp_gpio_set(bank, pin);
+ }
+ else {
+ sc = rtems_bsp_gpio_clear(bank, pin);
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+}
+
+int rtems_gpio_get_value(uint32_t pin_number)
+{
+ uint32_t bank;
+ uint32_t pin;
+ int rv;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return -1;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ if ( gpio_pin_state[bank][pin].pin_function != DIGITAL_INPUT) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ RTEMS_SYSLOG_ERROR("Can only read digital input pins\n");
+
+ return -1;
+ }
+
+ rv = rtems_bsp_gpio_get_value(bank, pin);
+
+ if ( gpio_pin_state[bank][pin].logic_invert && rv > 0 ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return !rv;
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return ( rv > 0 ) ? 1 : rv;
+}
+
+rtems_status_code rtems_gpio_request_pin(uint32_t pin_number, rtems_gpio_function function, bool output_enabled, bool logic_invert, void* bsp_specific)
+{
+ rtems_gpio_specific_data* bsp_data;
+ rtems_status_code sc = RTEMS_SUCCESSFUL;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ /* If the pin is already being used returns with an error. */
+ if ( gpio_pin_state[bank][pin].pin_function != NOT_USED ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_RESOURCE_IN_USE;
+ }
+
+ switch ( function ) {
+ case DIGITAL_INPUT:
+ sc = rtems_bsp_gpio_select_input(bank, pin, bsp_specific);
+ break;
+ case DIGITAL_OUTPUT:
+ sc = rtems_bsp_gpio_select_output(bank, pin, bsp_specific);
+ break;
+ case BSP_SPECIFIC:
+ bsp_data = (rtems_gpio_specific_data*) bsp_specific;
+
+ if ( bsp_data == NULL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ sc = rtems_bsp_select_specific_io(bank, pin, bsp_data->io_function, bsp_data->pin_data);
+ break;
+ case NOT_USED:
+ default:
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_NOT_DEFINED;
+ }
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+ }
+
+ /* If the function was successfuly assigned to the pin,
+ * record that information on the gpio_pin_state structure. */
+ gpio_pin_state[bank][pin].pin_function = function;
+ gpio_pin_state[bank][pin].logic_invert = logic_invert;
+
+ if ( function == DIGITAL_OUTPUT ) {
+ if ( output_enabled == true ) {
+ sc = rtems_bsp_gpio_set(bank, pin);
+ }
+ else {
+ sc = rtems_bsp_gpio_clear(bank, pin);
+ }
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+}
+
+rtems_status_code rtems_gpio_resistor_mode(uint32_t pin_number, rtems_gpio_pull_mode mode)
+{
+ rtems_status_code sc;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ /* If the desired actuation mode is already set, silently exits.
+ * The NO_PULL_RESISTOR is a special case, as some platforms have
+ * pull-up resistors enabled on startup, so this state may have to
+ * be reinforced in the hardware. */
+ if ( gpio_pin_state[bank][pin].resistor_mode == mode && mode != NO_PULL_RESISTOR ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+ }
+
+ sc = rtems_bsp_gpio_set_resistor_mode(bank, pin, mode);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+ }
+
+ gpio_pin_state[bank][pin].resistor_mode = mode;
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_release_pin(uint32_t pin_number)
+{
+ rtems_status_code sc;
+ gpio_pin* gpio;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ gpio = &gpio_pin_state[bank][pin];
+
+ /* If the pin has an enabled interrupt then remove the handler(s),
+ * and disable the interrupts on that pin. */
+ if ( gpio->enabled_interrupt != NONE ) {
+ sc = rtems_gpio_disable_interrupt(pin_number);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return sc;
+ }
+ }
+
+ gpio->pin_function = NOT_USED;
+ gpio->task_id = RTEMS_ID_NONE;
+ gpio->debouncing_tick_count = 0;
+ gpio->last_isr_tick = 0;
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_debounce_switch(uint32_t pin_number, int ticks)
+{
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ if ( gpio_pin_state[bank][pin].pin_function != DIGITAL_INPUT ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_NOT_CONFIGURED;
+ }
+
+ gpio_pin_state[bank][pin].debouncing_tick_count = ticks;
+ gpio_pin_state[bank][pin].last_isr_tick = rtems_clock_get_ticks_per_second();
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_interrupt_handler_install(
+uint32_t pin_number,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+)
+{
+ gpio_handler_list *isr_node;
+ gpio_pin* gpio;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ gpio = &gpio_pin_state[bank][pin];
+
+ /* If the current pin has no interrupt enabled
+ * then it does not need an handler. */
+ if ( gpio->enabled_interrupt == NONE ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_NOT_CONFIGURED;
+ }
+ /* If the pin already has an enabled interrupt but the installed handler
+ * is set as unique. */
+ else if ( gpio->handler_flag == UNIQUE_HANDLER && gpio->handler_list != NULL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_RESOURCE_IN_USE;
+ }
+
+ /* Update the pin's ISR list. */
+ isr_node = (gpio_handler_list *) malloc(sizeof(gpio_handler_list));
+
+ if ( isr_node == NULL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_NO_MEMORY;
+ }
+
+ isr_node->handler = handler;
+ isr_node->arg = arg;
+
+ if ( gpio->handler_flag == SHARED_HANDLER ) {
+ isr_node->next_isr = gpio->handler_list;
+ }
+ else {
+ isr_node->next_isr = NULL;
+ }
+
+ gpio->handler_list = isr_node;
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_enable_interrupt(
+uint32_t pin_number,
+rtems_gpio_interrupt interrupt,
+rtems_gpio_handler_flag flag,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+)
+{
+ rtems_vector_number vector;
+ rtems_status_code sc;
+ gpio_pin* gpio;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ vector = rtems_bsp_gpio_get_vector(bank);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ gpio = &gpio_pin_state[bank][pin];
+
+ if ( gpio->pin_function != DIGITAL_INPUT ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_NOT_CONFIGURED;
+ }
+
+ /* If trying to enable the same type of interrupt on the same pin, or if the pin
+ * already has an enabled interrupt. */
+ if ( interrupt == gpio->enabled_interrupt || gpio->enabled_interrupt != NONE ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_RESOURCE_IN_USE;
+ }
+
+ /* Creates and starts a new task which will call the corresponding
+ * user-defined handlers for this pin. */
+ sc = rtems_task_create(rtems_build_name('G', 'P', 'I', 'O'),
+ 5,
+ RTEMS_MINIMUM_STACK_SIZE * 2,
+ RTEMS_NO_TIMESLICE,
+ RTEMS_DEFAULT_ATTRIBUTES,
+ &gpio->task_id);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ sc = rtems_task_start(gpio->task_id, generic_handler_task, (rtems_task_argument) gpio);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ sc = rtems_task_delete(gpio->task_id);
+
+ assert( sc == RTEMS_SUCCESSFUL );
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ gpio->enabled_interrupt = interrupt;
+ gpio->handler_flag = flag;
+
+ /* Installs the interrupt handler. */
+ sc = rtems_gpio_interrupt_handler_install(pin_number, handler, arg);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ sc = rtems_task_delete(gpio->task_id);
+
+ assert( sc == RTEMS_SUCCESSFUL );
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ /* If the generic ISR has not been yet installed for this bank, installs it.
+ * This ISR will be responsible for calling the handler tasks,
+ * which in turn will call the user-defined interrupt handlers.*/
+ if ( interrupt_counter[bank] == 0 ) {
+ sc = rtems_interrupt_handler_install(vector,
+ "GPIO_HANDLER",
+ RTEMS_INTERRUPT_UNIQUE,
+ (rtems_interrupt_handler) generic_isr,
+ gpio_pin_state[bank]);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+ }
+
+ sc = rtems_bsp_enable_interrupt(bank, pin, interrupt);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ ++interrupt_counter[bank];
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_interrupt_handler_remove(
+uint32_t pin_number,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+)
+{
+ gpio_handler_list *isr_node, *next_node;
+ gpio_pin* gpio;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ gpio = &gpio_pin_state[bank][pin];
+
+ isr_node = gpio->handler_list;
+
+ if ( isr_node != NULL ) {
+ if ( isr_node->handler == handler && isr_node->arg == arg ) {
+ gpio->handler_list = isr_node->next_isr;
+
+ free(isr_node);
+ }
+ else {
+ while ( isr_node->next_isr != NULL ) {
+ if ( (isr_node->next_isr)->handler == handler && (isr_node->next_isr)->arg == arg ) {
+ next_node = (isr_node->next_isr)->next_isr;
+
+ free(isr_node->next_isr);
+
+ isr_node->next_isr = next_node;
+ }
+ }
+ }
+ }
+
+ /* If the removed handler was the last for this pin, disables further
+ * interrupts on this pin. */
+ if ( gpio->handler_list == NULL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return rtems_gpio_disable_interrupt(pin_number);
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
+
+rtems_status_code rtems_gpio_disable_interrupt(uint32_t pin_number)
+{
+ gpio_handler_list *isr_node;
+ rtems_vector_number vector;
+ rtems_status_code sc;
+ gpio_pin* gpio;
+ uint32_t bank;
+ uint32_t pin;
+
+ if ( pin_number < 0 || pin_number >= gpio_count ) {
+ return RTEMS_INVALID_ID;
+ }
+
+ bank = BANK_NUMBER(pin_number);
+ pin = PIN_NUMBER(pin_number);
+
+ vector = rtems_bsp_gpio_get_vector(bank);
+
+ AQUIRE_LOCK(bank_lock[bank]);
+
+ gpio = &gpio_pin_state[bank][pin];
+
+ if ( interrupt_counter[bank] == 0 || gpio->enabled_interrupt == NONE ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+ }
+
+ sc = rtems_bsp_disable_interrupt(bank, pin, gpio->enabled_interrupt);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+
+ gpio->enabled_interrupt = NONE;
+
+ while ( gpio->handler_list != NULL ) {
+ isr_node = gpio->handler_list;
+
+ gpio->handler_list = isr_node->next_isr;
+
+ free(isr_node);
+ }
+
+ sc = rtems_task_delete(gpio->task_id);
+
+ assert( sc == RTEMS_SUCCESSFUL );
+
+ --interrupt_counter[bank];
+
+ /* If no GPIO interrupts are left in this bank, removes the handler. */
+ if ( interrupt_counter[bank] == 0 ) {
+ sc = rtems_interrupt_handler_remove(vector,
+ (rtems_interrupt_handler) generic_isr,
+ gpio_pin_state[bank]);
+
+ if ( sc != RTEMS_SUCCESSFUL ) {
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_UNSATISFIED;
+ }
+ }
+
+ RELEASE_LOCK(bank_lock[bank]);
+
+ return RTEMS_SUCCESSFUL;
+}
diff --git a/c/src/lib/libbsp/shared/include/gpio.h b/c/src/lib/libbsp/shared/include/gpio.h
new file mode 100644
index 0000000..6a84747
--- /dev/null
+++ b/c/src/lib/libbsp/shared/include/gpio.h
@@ -0,0 +1,610 @@
+/**
+ * @file gpio.h
+ *
+ * @ingroup rtems_gpio
+ *
+ * @brief RTEMS GPIO API definition.
+ */
+
+/*
+ * Copyright (c) 2014-2015 Andre Marques <andre.lousa.marques at gmail.com>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#ifndef LIBBSP_SHARED__GPIO_H
+#define LIBBSP_SHARED__GPIO_H
+
+#include <rtems.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* __cplusplus */
+
+/**
+ * @name GPIO data structures
+ *
+ * @{
+ */
+
+/**
+ * @brief The set of possible configurations for a GPIO pull-up resistor.
+ *
+ * Enumerated type to define the possible pull-up resistor configuratons
+ * for a GPIO pin.
+ */
+typedef enum
+{
+ PULL_UP = 1,
+ PULL_DOWN,
+ NO_PULL_RESISTOR
+} rtems_gpio_pull_mode;
+
+/**
+ * @brief The set of possible functions a pin can have.
+ *
+ * Enumerated type to define a pin function.
+ */
+typedef enum
+{
+ DIGITAL_INPUT = 0,
+ DIGITAL_OUTPUT,
+ BSP_SPECIFIC,
+ NOT_USED
+} rtems_gpio_function;
+
+/**
+ * @brief The set of possible interrupts a GPIO pin can generate.
+ *
+ * Enumerated type to define a GPIO pin interrupt.
+ */
+typedef enum
+{
+ FALLING_EDGE = 0,
+ RISING_EDGE,
+ LOW_LEVEL,
+ HIGH_LEVEL,
+ BOTH_EDGES,
+ BOTH_LEVELS,
+ NONE
+} rtems_gpio_interrupt;
+
+/**
+ * @brief The set of possible handled states an user-defined interrupt
+ * handler can return.
+ *
+ * Enumerated type to define an interrupt handler handled state.
+ */
+typedef enum
+{
+ IRQ_HANDLED,
+ IRQ_NONE
+} rtems_gpio_irq_state;
+
+/**
+ * @brief The set of flags to specify an user-defined interrupt handler
+ * uniqueness on a GPIO pin.
+ *
+ * Enumerated type to define an interrupt handler shared flag.
+ */
+typedef enum
+{
+ SHARED_HANDLER,
+ UNIQUE_HANDLER
+} rtems_gpio_handler_flag;
+
+/**
+ * @brief Object containing relevant information for assigning a BSP specific
+ * function to a pin.
+ *
+ * Encapsulates relevant data for a BSP specific GPIO function.
+ */
+typedef struct
+{
+ /* The bsp defined function code. */
+ uint32_t io_function;
+
+ void* pin_data;
+} rtems_gpio_specific_data;
+
+/**
+ * @brief Object containing relevant information about a BSP's GPIO layout.
+ */
+typedef struct
+{
+ /* Total number of GPIO pins. */
+ uint32_t pin_count;
+
+ /* Number of pins per bank. The last bank may be smaller,
+ * depending on the total number of pins. */
+ uint32_t pins_per_bank;
+} rtems_gpio_layout;
+
+/**
+ * @brief Object containing configuration information
+ * regarding interrupts.
+ */
+typedef struct
+{
+ rtems_gpio_interrupt enabled_interrupt;
+
+ rtems_gpio_handler_flag handler_flag;
+
+ /* Interrupt handler function. */
+ rtems_gpio_irq_state (*handler) (void *arg);
+
+ /* Interrupt handler function arguments. */
+ void *arg;
+
+ /* Software switch debounce settings. It should contain the amount of clock
+ * ticks that must pass between interrupts to ensure that the interrupt
+ * was not caused by a switch bounce. If set to 0 this feature is disabled . */
+ uint32_t clock_tick_interval;
+} rtems_gpio_interrupt_conf;
+
+/**
+ * @brief Object containing configuration information
+ * to request/update a GPIO pin.
+ */
+typedef struct
+{
+ uint32_t pin_number;
+ rtems_gpio_function function;
+
+ /* Pull resistor setting. */
+ rtems_gpio_pull_mode pull_mode;
+
+ /* If digital out pin, set to TRUE to set the pin to logical high,
+ * or FALSE for logical low. If not a digital out then this
+ * is ignored. */
+ bool output_enabled;
+ bool logic_invert;
+
+ /* Pin interrupt configuration. Should be NULL if not used. */
+ rtems_gpio_interrupt_conf* interrupt;
+
+ /* Struct with bsp specific data, to use during the pin request.
+ * If function == BSP_SPECIFIC this should have a pointer to
+ * a rtems_gpio_specific_data struct.
+ *
+ * If not this field may be NULL. This is passed to the bsp function so any bsp specific data
+ * can be passed to it through this pointer. */
+ void* bsp_specific;
+} rtems_gpio_pin_conf;
+
+/** @} */
+
+/**
+ * @name gpio Usage
+ *
+ * @{
+ */
+
+/**
+ * @brief Initializes the GPIO API.
+ *
+ * @retval RTEMS_SUCCESSFUL API successfully initialized.
+ * @retval * For other error code see @rtems_semaphore_create().
+ */
+extern rtems_status_code rtems_gpio_initialize(void);
+
+/**
+ * @brief Requests a GPIO pin configuration from the API.
+ * It may be used either to request a new pin, or to update the
+ * configuration/functions of a pin currently in use.
+ *
+ * @param[in] conf rtems_gpio_pin_conf structure filled with the pin information
+ * and desired configurations.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was configured successfully.
+ * @retval RTEMS_UNSATISFIED Could not request/update the pin's configuration.
+ */
+extern rtems_status_code rtems_gpio_request_conf(rtems_gpio_pin_conf* conf);
+
+/**
+ * @brief Sets multiple output GPIO pins with the logical high.
+ *
+ * @param[in] count Number of GPIO pins to set.
+ * @param[in] ... Comma-separated list of GPIO pin numbers.
+ *
+ * @retval RTEMS_SUCCESSFUL All pins were set successfully.
+ * @retval RTEMS_INVALID_ID At least one pin number is invalid.
+ * @retval RTEMS_NOT_CONFIGURED At least one of the received pins
+ * is not configured as a digital output.
+ * @retval RTEMS_UNSATISFIED Could not set the GPIO pins.
+ */
+extern rtems_status_code rtems_gpio_multi_set(uint32_t count, ...);
+
+/**
+ * @brief Sets multiple output GPIO pins with the logical low.
+ *
+ * @param[in] count Number of GPIO pins to clear.
+ * @param[in] ... Comma-separated list of GPIO pin numbers.
+ *
+ * @retval RTEMS_SUCCESSFUL All pins were cleared successfully.
+ * @retval RTEMS_INVALID_ID At least one pin number is invalid.
+ * @retval RTEMS_NOT_CONFIGURED At least one of the received pins
+ * is not configured as a digital output.
+ * @retval RTEMS_UNSATISFIED Could not clear the GPIO pins.
+ */
+extern rtems_status_code rtems_gpio_multi_clear(uint32_t count, ...);
+
+/**
+ * @brief Sets an output GPIO pin with the logical high.
+ *
+ * @param[in] pin_number GPIO pin number.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was set successfully.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_NOT_CONFIGURED The received pin is not configured
+ * as a digital output.
+ * @retval RTEMS_UNSATISFIED Could not set the GPIO pin.
+ */
+extern rtems_status_code rtems_gpio_set(uint32_t pin_number);
+
+/**
+ * @brief Sets an output GPIO pin with the logical low.
+ *
+ * @param[in] pin_number GPIO pin number.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was cleared successfully.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_NOT_CONFIGURED The received pin is not configured
+ * as a digital output.
+ * @retval RTEMS_UNSATISFIED Could not clear the GPIO pin.
+ */
+extern rtems_status_code rtems_gpio_clear(uint32_t pin_number);
+
+/**
+ * @brief Returns the value (level) of a GPIO input pin.
+ *
+ * @param[in] pin_number GPIO pin number.
+ *
+ * @retval The function returns 0 or 1 depending on the pin current
+ * logical value.
+ * @retval -1 Pin number is invalid, or not a digital input pin.
+ */
+extern int rtems_gpio_get_value(uint32_t pin_number);
+
+/**
+ * @brief Assigns a certain function to a GPIO pin.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] function The new function for the pin.
+ * @param[in] output_enabled If TRUE and @var function is DIGITAL_OUTPUT,
+ * then the pin is set with the logical high.
+ * Otherwise it is set with logical low.
+ * @param[in] logic_invert Reverses the digital I/O logic for DIGITAL_INPUT
+ * and DIGITAL_OUTPUT pins.
+ * @param[in] bsp_specific Pointer to a bsp defined structure with bsp-specific
+ * data. This field is not handled by the API.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was configured successfully.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_RESOURCE_IN_USE The received pin is already being used.
+ * @retval RTEMS_UNSATISFIED Could not assign the GPIO function.
+ * @retval RTEMS_NOT_DEFINED GPIO function not defined, or NOT_USED.
+ */
+extern rtems_status_code rtems_gpio_request_pin(uint32_t pin_number, rtems_gpio_function function, bool output_enable, bool logic_invert, void* bsp_specific);
+
+/**
+ * @brief Configures a single GPIO pin pull resistor.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] mode The pull resistor mode.
+ *
+ * @retval RTEMS_SUCCESSFUL Pull resistor successfully configured.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_UNSATISFIED Could not set the pull mode.
+ */
+extern rtems_status_code rtems_gpio_resistor_mode(uint32_t pin_number, rtems_gpio_pull_mode mode);
+
+/**
+ * @brief Releases a GPIO pin from the API, making it available to be used
+ * again.
+ *
+ * @param[in] pin_number GPIO pin number.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin successfully disabled on the API.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval * Could not disable an ative interrupt on this pin,
+ * @see rtems_gpio_disable_interrupt().
+ */
+extern rtems_status_code rtems_gpio_release_pin(uint32_t pin_number);
+
+/**
+ * @brief Attaches a debouncing function to a given pin/switch.
+ * Debouncing is done by requiring a certain number of clock ticks to
+ * pass between interrupts. Any interrupt fired too close to the last
+ * will be ignored as it is probably the result of an involuntary
+ * switch/button bounce after being released.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] ticks Minimum number of clock ticks that must pass between
+ * interrupts so it can be considered a legitimate
+ * interrupt.
+ *
+ * @retval RTEMS_SUCCESSFUL De-bounce function successfully attached to the pin.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_NOT_CONFIGURED The current pin is not configured as a digital
+ * input, hence it can not be connected to a switch.
+ */
+extern rtems_status_code rtems_gpio_debounce_switch(uint32_t pin_number, int ticks);
+
+/**
+ * @brief Connects a new user-defined interrupt handler to a given pin.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] handler Pointer to a function that will be called every time
+ * the enabled interrupt for the given pin is generated.
+ * This function must return information about its
+ * handled/unhandled state.
+ * @param[in] arg Void pointer to the arguments of the user-defined handler.
+ *
+ * @retval RTEMS_SUCCESSFUL Handler successfully connected to this pin.
+ * @retval RTEMS_NO_MEMORY Could not connect more user-defined handlers to
+ * the given pin.
+ * @retval RTEMS_NOT_CONFIGURED The given pin has no interrupt configured.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_RESOURCE_IN_USE The current user-defined handler for this pin
+ * is unique.
+ */
+extern rtems_status_code rtems_gpio_interrupt_handler_install(
+uint32_t pin_number,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+);
+
+/**
+ * @brief Enables interrupts to be generated on a given GPIO pin.
+ * When fired that interrupt will call the given handler.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] interrupt Type of interrupt to enable for the pin.
+ * @param[in] handler Pointer to a function that will be called every time
+ * @var interrupt is generated. This function must return
+ * information about its handled/unhandled state.
+ * @param[in] arg Void pointer to the arguments of the user-defined handler.
+ *
+ * @retval RTEMS_SUCCESSFUL Interrupt successfully enabled for this pin.
+ * @retval RTEMS_UNSATISFIED Could not install the GPIO ISR, create/start
+ * the handler task, or enable the interrupt
+ * on the pin.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_RESOURCE_IN_USE The pin already has an enabled interrupt.
+ */
+extern rtems_status_code rtems_gpio_enable_interrupt(
+uint32_t pin_number,
+rtems_gpio_interrupt interrupt,
+rtems_gpio_handler_flag flag,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+);
+
+/**
+ * @brief Disconnects an user-defined interrupt handler from the given pin.
+ * If in the end there are no more user-defined handlers connected
+ * to the pin, interrupts are disabled on the given pin.
+ *
+ * @param[in] pin_number GPIO pin number.
+ * @param[in] handler Pointer to the user-defined handler
+ * @param[in] arg Void pointer to the arguments of the user-defined handler.
+ *
+ * @retval RTEMS_SUCCESSFUL Handler successfully disconnected from this pin.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval * @see rtems_gpio_disable_interrupt()
+ */
+rtems_status_code rtems_gpio_interrupt_handler_remove(
+uint32_t pin_number,
+rtems_gpio_irq_state (*handler) (void *arg),
+void *arg
+);
+
+/**
+ * @brief Stops interrupts from being generated on a given GPIO pin
+ * and removes the corresponding handler.
+ *
+ * @param[in] pin_number GPIO pin number.
+ *
+ * @retval RTEMS_SUCCESSFUL Interrupt successfully disabled for this pin.
+ * @retval RTEMS_INVALID_ID Pin number is invalid.
+ * @retval RTEMS_UNSATISFIED Could not remove the current interrupt handler,
+ * could not recognise the current active interrupt
+ * on this pin or could not disable interrupts on
+ * this pin.
+ */
+extern rtems_status_code rtems_gpio_disable_interrupt(uint32_t pin_number);
+
+/**
+ * @brief Defines the GPIO pin layout. This must be implemented by each BSP.
+ */
+extern rtems_gpio_layout rtems_bsp_gpio_initialize(void);
+
+/**
+ * @brief Sets multiple output GPIO pins with the logical high. This must be implemented
+ * by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] bitmask Bitmask of GPIO pins to set in the given bank.
+ *
+ * @retval RTEMS_SUCCESSFUL All pins were set successfully.
+ * @retval RTEMS_UNSATISFIED Could not set at least one of the pins.
+ */
+extern rtems_status_code rtems_bsp_gpio_multi_set(uint32_t bank, uint32_t bitmask);
+
+/**
+ * @brief Sets multiple output GPIO pins with the logical low. This must be implemented
+ * by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] bitmask Bitmask of GPIO pins to clear in the given bank.
+ *
+ * @retval RTEMS_SUCCESSFUL All pins were cleared successfully.
+ * @retval RTEMS_UNSATISFIED Could not clear at least one of the pins.
+ */
+extern rtems_status_code rtems_bsp_gpio_multi_clear(uint32_t bank, uint32_t bitmask);
+
+/**
+ * @brief Sets an output GPIO pin with the logical high. This must be implemented
+ * by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was set successfully.
+ * @retval RTEMS_UNSATISFIED Could not set the given pin.
+ */
+extern rtems_status_code rtems_bsp_gpio_set(uint32_t bank, uint32_t pin);
+
+/**
+ * @brief Sets an output GPIO pin with the logical low. This must be implemented
+ * by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ *
+ * @retval RTEMS_SUCCESSFUL Pin was cleared successfully.
+ * @retval RTEMS_UNSATISFIED Could not clear the given pin.
+ */
+extern rtems_status_code rtems_bsp_gpio_clear(uint32_t bank, uint32_t pin);
+
+/**
+ * @brief Returns the value (level) of a GPIO input pin. This must be implemented
+ * by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ *
+ * @retval The function must return 0 or 1 depending on the pin current
+ * logical value.
+ * @retval -1 Could not read the pin level.
+ */
+extern int rtems_bsp_gpio_get_value(uint32_t bank, uint32_t pin);
+
+/**
+ * @brief Assigns the digital input function to the given pin.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] bsp_specific Pointer to a bsp defined structure with bsp-specific
+ * data.
+ *
+ * @retval RTEMS_SUCCESSFUL Function was asssigned successfully.
+ * @retval RTEMS_UNSATISFIED Could not assign the function to the pin.
+ */
+extern rtems_status_code rtems_bsp_gpio_select_input(uint32_t bank, uint32_t pin, void* bsp_specific);
+
+/**
+ * @brief Assigns the digital output function to the given pin.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] bsp_specific Pointer to a bsp defined structure with bsp-specific
+ * data.
+ *
+ * @retval RTEMS_SUCCESSFUL Function was asssigned successfully.
+ * @retval RTEMS_UNSATISFIED Could not assign the function to the pin.
+ */
+extern rtems_status_code rtems_bsp_gpio_select_output(uint32_t bank, uint32_t pin, void* bsp_specific);
+
+/**
+ * @brief Assigns a bsp specific function to the given pin.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] function Bsp defined GPIO function.
+ * @param[in] pin_data Pointer to a bsp defined structure with bsp-specific
+ * data.
+ *
+ * @retval RTEMS_SUCCESSFUL Function was asssigned successfully.
+ * @retval RTEMS_UNSATISFIED Could not assign the function to the pin.
+ */
+extern rtems_status_code rtems_bsp_select_specific_io(uint32_t bank, uint32_t pin, uint32_t function, void* pin_data);
+
+/**
+ * @brief Configures a single GPIO pin pull resistor.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] mode The pull resistor mode.
+ *
+ * @retval RTEMS_SUCCESSFUL Pull resistor successfully configured.
+ * @retval RTEMS_UNSATISFIED Could not set the pull mode.
+ */
+extern rtems_status_code rtems_bsp_gpio_set_resistor_mode(uint32_t bank, uint32_t pin, rtems_gpio_pull_mode mode);
+
+/**
+ * @brief Reads and returns a vector/bank interrupt event line.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] vector GPIO vector/bank.
+ *
+ * @retval Bitmask (max 32-bit) representing a GPIO bank, where a bit set
+ * indicates an active interrupt on that pin.
+ */
+extern uint32_t rtems_bsp_gpio_interrupt_line(rtems_vector_number vector);
+
+/**
+ * @brief Clears a vector/bank interrupt event line.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] vector GPIO vector/bank.
+ * @param[in] event_status Bitmask with the processed interrupts on the given
+ * vector. This bitmask is the same as calculated in
+ * @see rtems_bsp_gpio_interrupt_line().
+ */
+extern void rtems_bsp_gpio_clear_interrupt_line(rtems_vector_number vector, uint32_t event_status);
+
+/**
+ * @brief Calculates a vector number for a given GPIO bank.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ *
+ * @retval The corresponding rtems_vector_number.
+ */
+extern rtems_vector_number rtems_bsp_gpio_get_vector(uint32_t bank);
+
+/**
+ * @brief Enables interrupts to be generated on a given GPIO pin.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] interrupt Type of interrupt to enable for the pin.
+ *
+ * @retval RTEMS_SUCCESSFUL Interrupt successfully enabled for this pin.
+ * @retval RTEMS_UNSATISFIED Could not enable the interrupt on the pin.
+ */
+extern rtems_status_code rtems_bsp_enable_interrupt(uint32_t bank, uint32_t pin, rtems_gpio_interrupt interrupt);
+
+/**
+ * @brief Disables interrupt on hardware. This must be implemented by each BSP.
+ */
+
+/**
+ * @brief Stops interrupts from being generated on a given GPIO pin.
+ * This must be implemented by each BSP.
+ *
+ * @param[in] bank GPIO bank number.
+ * @param[in] pin GPIO pin number within the given bank.
+ * @param[in] enabled_interrupt Interrupt type currently active on this pin.
+ *
+ * @retval RTEMS_SUCCESSFUL Interrupt successfully disabled for this pin.
+ * @retval RTEMS_UNSATISFIED Could not disable interrupts on this pin.
+ */
+extern rtems_status_code rtems_bsp_disable_interrupt(uint32_t bank, uint32_t pin, rtems_gpio_interrupt enabled_interrupt);
+
+/** @} */
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+
+#endif /* LIBBSP_SHARED__GPIO_H */
--
2.0.5
More information about the devel
mailing list