File content as of revision 627:4fa1328d9c60:

/***************************************************************************//**
 * @file gpio_api.c
 *******************************************************************************
 * @section License
 * <b>(C) Copyright 2015 Silicon Labs, http://www.silabs.com</b>
 *******************************************************************************
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 *    claim that you wrote the original software.
 * 2. Altered source versions must be plainly marked as such, and must not be
 *    misrepresented as being the original software.
 * 3. This notice may not be removed or altered from any source distribution.
 *
 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Silicon Labs has no
 * obligation to support this Software. Silicon Labs is providing the
 * Software "AS IS", with no express or implied warranties of any kind,
 * including, but not limited to, any implied warranties of merchantability
 * or fitness for any particular purpose or warranties against infringement
 * of any proprietary rights of a third party.
 *
 * Silicon Labs will not be liable for any consequential, incidental, or
 * special damages, or any other relief, or for any claim by any third party,
 * arising from your use of this Software.
 *
 ******************************************************************************/

#include "gpio_api.h"
#include "pinmap.h"
#include "em_cmu.h"
#include "mbed_assert.h"
#include "sleepmodes.h"


void gpio_write(gpio_t *obj, int value)
{
    if (value) {
        GPIO_PinOutSet((GPIO_Port_TypeDef)(obj->pin >> 4 & 0xF), obj->pin & 0xF); // Pin number encoded in first four bits of obj->pin
    } else {
        GPIO_PinOutClear((GPIO_Port_TypeDef)(obj->pin >> 4 & 0xF), obj->pin & 0xF);
    }
}

int gpio_read(gpio_t *obj)
{
    if (obj->dir == PIN_INPUT) {
        return GPIO_PinInGet((GPIO_Port_TypeDef)(obj->pin >> 4 & 0xF), obj->pin & 0xF); // Pin number encoded in first four bits of obj->pin
    } else {
        return GPIO_PinOutGet((GPIO_Port_TypeDef)(obj->pin >> 4 & 0xF), obj->pin & 0xF);
    }
}

int gpio_is_connected(const gpio_t *obj)
{
    return (obj->pin | 0xFFFFFF00 )!= (PinName)NC;
}

/*
 * @return the GPIO port mask for this pin
 * Pin and port index encoded in one uint32.
 * First four bits represent the pin number
 * The remaining bits represent the pin mode
 */
uint32_t gpio_set(PinName pin)
{
    return 1 << ((uint32_t) pin & 0xF);
}

void gpio_init(gpio_t *obj, PinName pin)
{
    MBED_ASSERT(pin != NC);

    CMU_ClockEnable(cmuClock_HFPER, true);
    CMU_ClockEnable(cmuClock_GPIO, true);
    obj->pin = pin;
}

void gpio_mode(gpio_t *obj, PinMode mode)
{
        if(obj->dir == PIN_INPUT) {
        switch(mode) {
            case PullDefault:
                mode = Input;
                break;
            case PullUp:
                mode = InputPullUp;
                break;
            case PullDown:
                mode = InputPullDown;
                break;
            default:
                break;
        }
        
        //Handle DOUT setting
        if((mode & 0x10) != 0) {
            //Set DOUT
            GPIO->P[(obj->pin >> 4) & 0xF].DOUTSET = 1 << (obj->pin & 0xF);
        } else {
            //Clear DOUT
            GPIO->P[(obj->pin >> 4) & 0xF].DOUTCLR = 1 << (obj->pin & 0xF);
        }
    } else {
        switch(mode) {
            case PullDefault:
                mode = PushPull;
                break;
            case PullUp:
                mode = WiredAndPullUp;
                break;
            case PullDown:
                mode = WiredOrPullDown;
                break;
            default:
                break;
        }
    }
    
    obj->mode = mode; // Update object
    pin_mode(obj->pin, mode); // Update register
}

// Used by DigitalInOut to set correct mode when direction is set
void gpio_dir(gpio_t *obj, PinDirection direction)
{
    obj->dir = direction;
    switch (direction) {
        case PIN_INPUT:
            gpio_mode(obj, PullDefault);
            break;
        case PIN_OUTPUT:
            gpio_mode(obj, PullNone);
            break;
    }
}