File content as of revision 15:9801f08ce0ee:

#include "mbed.h"
#include "rtos.h"

#include "gpio_api.h"
#include "max32625pico.h"
#include "pwrman_regs.h"

// #define MAX_GPIO_API 1
#define MAX_GPIO_DIRECT 1

// #define MAX_I2C_API 1

static DigitalOut rLED(LED1);
static DigitalOut gLED(LED2);
static DigitalOut bLED(LED3);

void gpioOpenDrainWeakPullup(PinName name) {
    const unsigned int port = PINNAME_TO_PORT(name);
    const unsigned int pin = PINNAME_TO_PIN(name);
    /* Set function; Firmware Control (GPIO mode) */
    MXC_GPIO->func_sel[port] &= ~(0xF << (4 * pin));
    /* Normal input is always enabled */
    MXC_GPIO->in_mode[port] &= ~(0xF << (4 * pin));
    const uint32_t new_mode = MXC_V_GPIO_OUT_MODE_OPEN_DRAIN_WEAK_PULLUP;
    uint32_t out_mode = MXC_GPIO->out_mode[port];
    out_mode &= ~(0xF << (pin * 4));
    out_mode |= (new_mode << (pin * 4));
    MXC_GPIO->out_mode[port] = out_mode;
}

int gpioAlternatePullup() {
    // AN6350 5.2.4.1
    int result = E_NO_ERROR;
    MXC_IOMAN->wud_req0 |= (0xc0 << 8);  // Port 1 Pins 6,7
    if (MXC_IOMAN->wud_ack0 != MXC_IOMAN->wud_req0) {
        result = E_BUSY;
    }
    if (result == E_NO_ERROR) {
        /* Enable modifications to WUD configuration */
        MXC_PWRMAN->wud_ctrl = MXC_F_PWRMAN_WUD_CTRL_CTRL_ENABLE;
        MXC_PWRMAN->wud_ctrl |= (1 * 8) + 6;  // Pad 1.6
        MXC_PWRMAN->wud_ctrl &= ~(MXC_F_PWRMAN_WUD_CTRL_PAD_MODE);
        MXC_PWRMAN->wud_ctrl |= (MXC_E_PWRMAN_PAD_MODE_WEAK_HI_LO << MXC_F_PWRMAN_WUD_CTRL_PAD_MODE_POS);
        MXC_PWRMAN->wud_pulse0 = 1;

        /* Enable modifications to WUD configuration */
        MXC_PWRMAN->wud_ctrl = MXC_F_PWRMAN_WUD_CTRL_CTRL_ENABLE;
        MXC_PWRMAN->wud_ctrl |= (1 * 8) + 7;  // Pad 1.7
        MXC_PWRMAN->wud_ctrl &= ~(MXC_F_PWRMAN_WUD_CTRL_PAD_MODE);
        MXC_PWRMAN->wud_ctrl |= (MXC_E_PWRMAN_PAD_MODE_WEAK_HI_LO << MXC_F_PWRMAN_WUD_CTRL_PAD_MODE_POS);
        MXC_PWRMAN->wud_pulse0 = 1;
    }
    /* Disable configuration each time, required by hardware */
    MXC_PWRMAN->wud_ctrl = 0;
    MXC_IOMAN->wud_req0 = 0;
    return result;
}

int main()
{
    rLED = LED_ON;
    gLED = LED_ON;
    bLED = LED_OFF;

    MAX32625PICO pico(
        MAX32625PICO::IOH_3V3, MAX32625PICO::VIO_IOH, MAX32625PICO::VIO_IOH);

    gpio_t gpio_p1_6;
    gpio_t gpio_p1_7;
    gpio_init(&gpio_p1_6, P1_6);
    gpio_init(&gpio_p1_7, P1_7);
#ifdef MAX_GPIO_API
    // gpio_api.c:104 sets the pin to MXC_V_GPIO_OUT_MODE_HIGH_Z_WEAK_PULLUP
    pin_dir_mode(P1_6, PIN_INPUT, PullUp);
    pin_dir_mode(P1_7, PIN_INPUT, PullUp);
#elif MAX_GPIO_DIRECT
    // gpioOpenDrainWeakPullup(P1_6);
    // gpioOpenDrainWeakPullup(P1_7);
    gpioAlternatePullup();
#else
    DigitalInOut(P1_6, PIN_INPUT, PullUp, 1);
    DigitalInOut(P1_7, PIN_INPUT, PullUp, 1);
#endif

    Thread::wait(5);

#ifdef MAX_I2C_API
    i2c_t i2c_o;
    i2c_init(&i2c_o, P1_6, P1_7);
#else
    I2C i2c(P1_6, P1_7);
    i2c.frequency(10000);
#endif

    rLED = LED_OFF;
    gLED = LED_OFF;

    char dbuf[32];
    while(1) {
        Thread::wait(15);
#ifdef MAX_I2C_API
        if (i2c_read(&i2c_o, 0x55, dbuf, 8, 1) > 0) {
#else
        if (i2c.read(0x55, dbuf, 8) == 0) {
#endif
            gLED = !gLED;
        } else {
            rLED = !rLED;
        }
    }
}