exti_common_all.c

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/** @addtogroup exti_file EXTI peripheral API
 * @ingroup peripheral_apis
 */
/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2010 Mark Butler <mbutler@physics.otago.ac.nz>
 * Copyright (C) 2012 Karl Palsson <karlp@tweak.net.au>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 *
 * This provides the code for the "next gen" EXTI block provided in F2/F4/F7/L1
 * devices.  (differences only in the source selection)
 */
/**@{*/
 
 
#include <libopencm3/stm32/exti.h>
#include <libopencm3/stm32/gpio.h>
 
#if defined(EXTI_EXTICR)
        #define EXTICR_SELECTION_FIELDSIZE      EXTI_EXTICR_FIELDSIZE
        #define EXTICR_SELECTION_REG(x) EXTI_EXTICR(x)
#elif defined(AFIO_EXTICR)
        #define EXTICR_SELECTION_FIELDSIZE      AFIO_EXTICR_FIELDSIZE
        #define EXTICR_SELECTION_REG(x) AFIO_EXTICR(x)
#else
        #include <libopencm3/stm32/syscfg.h>
        #define EXTICR_SELECTION_FIELDSIZE      SYSCFG_EXTICR_FIELDSIZE
        #define EXTICR_SELECTION_REG(x) SYSCFG_EXTICR(x)
#endif
 
void exti_set_trigger(uint32_t extis, enum exti_trigger_type trig)
{
        switch (trig) {
        case EXTI_TRIGGER_RISING:
                EXTI_RTSR |= extis;
                EXTI_FTSR &= ~extis;
                break;
        case EXTI_TRIGGER_FALLING:
                EXTI_RTSR &= ~extis;
                EXTI_FTSR |= extis;
                break;
        case EXTI_TRIGGER_BOTH:
                EXTI_RTSR |= extis;
                EXTI_FTSR |= extis;
                break;
        }
}
 
void exti_enable_request(uint32_t extis)
{
        /* Enable interrupts. */
        EXTI_IMR |= extis;
 
        /* Enable events. */
        EXTI_EMR |= extis;
}
 
void exti_disable_request(uint32_t extis)
{
        /* Disable interrupts. */
        EXTI_IMR &= ~extis;
 
        /* Disable events. */
        EXTI_EMR &= ~extis;
}
 
/*
 * Reset the interrupt request by writing a 1 to the corresponding
 * pending bit register.
 */
void exti_reset_request(uint32_t extis)
{
#if defined(EXTI_RPR1) && defined(EXTI_FPR1)
        EXTI_RPR1 = extis;
        EXTI_FPR1 = extis;
#else
        EXTI_PR = extis;
#endif
}
 
/*
 * Check the flag of a given EXTI interrupt.
 * */
uint32_t exti_get_flag_status(uint32_t exti)
{
#if defined(EXTI_RPR1) && defined(EXTI_FPR1)
        return (EXTI_RPR1 & exti) | (EXTI_FPR1 & exti);
#else
        return EXTI_PR & exti;
#endif
}
 
/*
 * Remap an external interrupt line to the corresponding pin on the
 * specified GPIO port.
 *
 * TODO: This could be rewritten in fewer lines of code.
 */
void exti_select_source(uint32_t exti, uint32_t gpioport)
{
        uint32_t line;
        for (line = 0; line < 16; line++) {
                if (!(exti & (1 << line))) {
                        continue;
                }
 
                uint32_t bits = 0;
 
                switch (gpioport) {
                case GPIOA:
                        bits = 0;
                        break;
                case GPIOB:
                        bits = 1;
                        break;
                case GPIOC:
                        bits = 2;
                        break;
                case GPIOD:
                        bits = 3;
                        break;
#if defined(GPIOE) && defined(GPIO_PORT_E_BASE)
                case GPIOE:
                        bits = 4;
                        break;
#endif
#if defined(GPIOF) && defined(GPIO_PORT_F_BASE)
                case GPIOF:
                        bits = 5;
                        break;
#endif
#if defined(GPIOG) && defined(GPIO_PORT_G_BASE)
                case GPIOG:
                        bits = 6;
                        break;
#endif
#if defined(GPIOH) && defined(GPIO_PORT_H_BASE)
                case GPIOH:
                        bits = 7;
                        break;
#endif
#if defined(GPIOI) && defined(GPIO_PORT_I_BASE)
                case GPIOI:
                        bits = 8;
                        break;
#endif
#if defined(GPIOJ) && defined(GPIO_PORT_J_BASE)
                case GPIOJ:
                        bits = 9;
                        break;
#endif
#if defined(GPIOK) && defined(GPIO_PORT_K_BASE)
                case GPIOK:
                        bits = 10;
                        break;
#endif
                }
 
                uint8_t shift = (uint8_t)(EXTICR_SELECTION_FIELDSIZE * (line % 4));
                uint32_t mask = ((1 << EXTICR_SELECTION_FIELDSIZE) - 1) << shift;
                uint32_t reg = line / 4;
 
                EXTICR_SELECTION_REG(reg) = (EXTICR_SELECTION_REG(reg) & ~mask) | (bits << shift);
        };
}
/**@}*/