From 388f940475b6c66c0622f3ab1a9a48e5fed96775 Mon Sep 17 00:00:00 2001 From: Thomas Otto Date: Wed, 12 May 2010 18:10:38 +0200 Subject: Initial EXTI support. Thanks to Mark Butler . --- lib/exti.c | 131 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 131 insertions(+) create mode 100644 lib/exti.c (limited to 'lib/exti.c') diff --git a/lib/exti.c b/lib/exti.c new file mode 100644 index 0000000..ccef676 --- /dev/null +++ b/lib/exti.c @@ -0,0 +1,131 @@ +/* + * This file is part of the libopenstm32 project. + * + * Copyright (C) 2010 Mark Butler + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include + +void exti_set_trigger(u32 extis, 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(u32 extis) +{ + //enable interrupts + EXTI_IMR |= extis; + //enable events + EXTI_EMR |= extis; +} + +void exti_disable_request(u32 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(u32 extis) +{ + EXTI_PR |= extis; +} + + +/*Remap an external interrupt line to the corresponding +pin on the specified GPIO port TODO: this could be rewritten in less lines of code */ +void exti_select_source(u32 exti, u32 gpioport) +{ + u8 shift =0; + u8 bits = 0; + switch (exti) + { + case EXTI0: + case EXTI4: + case EXTI8: + case EXTI12: + shift = 0; + break; + case EXTI1: + case EXTI5: + case EXTI9: + case EXTI13: + shift = 4; + break; + case EXTI2: + case EXTI6: + case EXTI10: + case EXTI14: + shift = 8; + break; + case EXTI3: + case EXTI7: + case EXTI11: + case EXTI15: + shift = 12; + break; + } + + switch (gpioport) + { + case GPIOA: + bits = 0xF; + break; + case GPIOB: + bits = 0xE; + break; + case GPIOC: + bits = 0xD; + break; + case GPIOD: + bits = 0xC; + break; + case GPIOE: + bits = 0xB; + break; + case GPIOF: + bits = 0xA; + break; + case GPIOG: + bits = 0x9; + break; + } + + if(exti < EXTI4) AFIO_EXTICR1 &=~ ( bits << shift ); + else if (exti < EXTI8) AFIO_EXTICR2 &=~ ( bits << shift ); + else if (exti < EXTI12) AFIO_EXTICR3 &=~ ( bits << shift ); + else if (exti < EXTI16) AFIO_EXTICR4 &=~ ( bits << shift ); //ensure that only valid EXTI lines are used +} \ No newline at end of file -- cgit v1.2.3