Initial import of low-level GPIO driver interface

drivers/include/periph/gpio.h

+/*
+ * Copyright (C) 2014 Freie Universität Berlin
+ *
+ * This file is subject to the terms and conditions of the LGPLv2 License.
+ * See the file LICENSE in the top level directory for more details.
+ */
+
+/**
+ * @ingroup     driver_periph
+ * @brief       Low-level GPIO periphial driver
+ * @{
+ *
+ * @file        gpio.h
+ * @brief       Low-level GPIO periphial driver interface definitions
+ *
+ * @author      Hauke Petersen <hauke.petersen@fu-berlin.de>
+ */
+
+#ifndef __GPIO_H
+#define __GPIO_H
+
+#include "periph_conf.h"
+
+
+/**
+ * @brief Definition of available GPIO devices. Each device is managin exactly one pin.
+ */
+#ifdef GPIO_NUMOF
+typedef enum {
+#ifdef GPIO_0_EN
+    GPIO_0 = 0,             ///< GPIO device 0
+#endif
+#ifdef GPIO_1_EN
+    GPIO_1,                 ///< GPIO device 1
+#endif
+#ifdef GPIO_2_EN
+    GPIO_2,                 ///< GPIO device 2
+#endif
+#ifdef GPIO_3_EN
+    GPIO_3,                 ///< GPIO device 3
+#endif
+#ifdef GPIO_4_EN
+    GPIO_4,                 ///< GPIO device 4
+#endif
+#ifdef GPIO_5_EN
+    GPIO_5,                 ///< GPIO device 5
+#endif
+#ifdef GPIO_6_EN
+    GPIO_6,                 ///< GPIO device 6
+#endif
+#ifdef GPIO_7_EN
+    GPIO_7,                 ///< GPIO device 7
+#endif
+#ifdef GPIO_8_EN
+    GPIO_8,                 ///< GPIO device 8
+#endif
+#ifdef GPIO_9_EN
+    GPIO_9,                 ///< GPIO device 9
+#endif
+#ifdef GPIO_10_EN
+    GPIO_10,                ///< GPIO device 10
+#endif
+#ifdef GPIO_11_EN
+    GPIO_11,                ///< GPIO device 11
+#endif
+#ifdef GPIO_12_EN
+    GPIO_12,                ///< GPIO device 12
+#endif
+#ifdef GPIO_13_EN
+    GPIO_13,                ///< GPIO device 13
+#endif
+#ifdef GPIO_14_EN
+    GPIO_14,                ///< GPIO device 14
+#endif
+#ifdef GPIO_15_EN
+    GPIO_15                 ///< GPIO device 15
+#endif
+} gpio_t;
+#endif
+
+/**
+ * @brief Definition of pull-up/pull-down modes
+ */
+typedef enum {
+    GPIO_PULLDOWN,          ///< enable internal pull-down resistor
+    GPIO_PULLUP,            ///< enable internal pull-up resistor
+    GPIO_NOPULL             ///< do not use internal pull resistors
+} gpio_pp_t;
+
+/**
+ * @brief Definition of possible active flanks for external interrupt mode
+ */
+typedef enum {
+    GPIO_FALLING,           ///< emit interrupt on falling flank
+    GPIO_RISING,            ///< emit interrupt on rising flank
+    GPIO_BOTH               ///< emit interrupt on both flanks
+} gpio_flank_t;
+
+/**
+ * @brief Initialize GPIO pin as output pin
+ * 
+ * @param dev       the GPIO pin to set as output
+ * @param pullup    define if pull resistors should be used
+ */
+void gpio_init_out(gpio_t dev, gpio_pp_t pullup);
+
+/**
+ * @brief Initialize a GPIO pin in input mode
+ * 
+ * @param dev       the GPIO pin to use as input
+ * @param pullup    define if pull resistors should be used
+ */
+void gpio_init_in(gpio_t dev, gpio_pp_t pullup);
+
+/**
+ * @brief Initialize a GPIO pin for external interrupt usage
+ * 
+ * The registerd callback function will be called in interrupt context everytime the defined flank(s)
+ * are detected.
+ * 
+ * The interrupt is activated automatically after the initialization.
+ * 
+ * @param dev       the GPIO pin to initialize
+ * @param pullup    define if pull resistors should be enabled
+ * @param flank     define the active flank(s)
+ * @param cb        register the callback that is called in interrupt context
+ */
+void gpio_init_int(gpio_t dev, gpio_pp_t pullup, gpio_flank_t flank, void (*cb)(void));
+
+/**
+ * @brief Get the current value of the given GPIO pin
+ * 
+ * @param dev       the GPIO pin to read
+ * @return          the current value, 0 for LOW, != 0 for HIGH
+ */
+int gpio_read(gpio_t dev);
+
+/**
+ * @brief Set the given GPIO pin to HIGH
+ * 
+ * @param dev       the GPIO pin to set
+ */
+void gpio_set(gpio_t dev);
+
+/**
+ * @brief Set the given GPIO pin to LOW
+ * 
+ * @param dev       the GPIO pin to clear
+ */
+void gpio_clear(gpio_t dev);
+
+/**
+ * @brief Toggle the value of the given GPIO pin
+ * 
+ * @param dev       the GPIO pin to toggle
+ */
+void gpio_toggle(gpio_t dev);
+
+/**
+ * @brief Set the given GPIO pin to the given value
+ * 
+ * @param dev       the GPIO pin to set
+ * @param value     value to set the pin to, 0 for LOW, HIGH otherwise
+ */
+void gpio_write(gpio_t dev, int value);
+
+#endif /* __GPIO_H */
+/** @} */