twr_module_encoder.c

#include <twr_module_encoder.h>
#include <twr_scheduler.h>
#include <twr_exti.h>
#include <twr_irq.h>
#include <twr_system.h>
#include <twr_timer.h>
 
static struct
{
    bool initialized;
    twr_scheduler_task_id_t task_id;
    void (*event_handler)(twr_module_encoder_event_t, void *);
    void *event_param;
    twr_button_t button;
    int increment;
    int increment_shadow;
    int samples;
 
} _twr_module_encoder;
 
static void _twr_module_encoder_task(void *param);
 
static void _twr_module_encoder_exti_handler(twr_exti_line_t line, void *param);
 
static void _twr_module_encoder_button_event_handler(twr_button_t *self, twr_button_event_t event, void *event_param);
 
static bool _twr_module_encoder_present_test(void);
 
void twr_module_encoder_init(void)
{
    memset(&_twr_module_encoder, 0, sizeof(_twr_module_encoder));
 
    // Initialize encoder button
    twr_button_init(&_twr_module_encoder.button, TWR_GPIO_BUTTON, TWR_GPIO_PULL_DOWN, false);
    twr_button_set_event_handler(&_twr_module_encoder.button, _twr_module_encoder_button_event_handler, NULL);
 
    // Init encoder GPIO pins
    twr_gpio_init(TWR_GPIO_P4);
 
    twr_gpio_init(TWR_GPIO_P5);
 
    // Register task
    _twr_module_encoder.task_id = twr_scheduler_register(_twr_module_encoder_task, NULL, 0);
}
 
void twr_module_encoder_deinit(void)
{
    // Unregister task
    twr_scheduler_unregister(_twr_module_encoder.task_id);
 
    twr_gpio_set_mode(TWR_GPIO_P4, TWR_GPIO_MODE_ANALOG);
 
    twr_gpio_set_mode(TWR_GPIO_P5, TWR_GPIO_MODE_ANALOG);
 
    if (_twr_module_encoder.initialized)
    {
        twr_exti_unregister(TWR_EXTI_LINE_P4);
 
        twr_exti_unregister(TWR_EXTI_LINE_P5);
    }
}
 
void twr_module_encoder_set_event_handler(void (*event_handler)(twr_module_encoder_event_t, void *), void *event_param)
{
    _twr_module_encoder.event_handler = event_handler;
 
    _twr_module_encoder.event_param = event_param;
}
 
twr_button_t *twr_module_encoder_get_button_instance(void)
{
    return &_twr_module_encoder.button;
}
 
int twr_module_encoder_get_increment(void)
{
    return _twr_module_encoder.increment_shadow;
}
 
bool twr_module_encoder_is_present(void)
{
    if (_twr_module_encoder.initialized)
    {
        return true;
    }
 
    return _twr_module_encoder_present_test();
}
 
static void _twr_module_encoder_task(void *param)
{
    (void) param;
 
    if (_twr_module_encoder.initialized)
    {
        // Disable interrupts
        twr_irq_disable();
 
        _twr_module_encoder.increment_shadow = _twr_module_encoder.increment;
        _twr_module_encoder.increment = 0;
 
        // Enable interrupts
        twr_irq_enable();
 
        if (_twr_module_encoder.increment_shadow != 0)
        {
            if (_twr_module_encoder.event_handler != NULL)
            {
                _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_ROTATION, _twr_module_encoder.event_param);
            }
        }
    }
    else
    {
        if (_twr_module_encoder_present_test())
        {
            // Set encoder GPIO pins as inputs
            twr_gpio_set_mode(TWR_GPIO_P4, TWR_GPIO_MODE_INPUT);
            twr_gpio_set_mode(TWR_GPIO_P5, TWR_GPIO_MODE_INPUT);
 
            // Remember initial GPIO states
            _twr_module_encoder.samples |= twr_gpio_get_input(TWR_GPIO_P4) ? 0x1 : 0;
            _twr_module_encoder.samples |= twr_gpio_get_input(TWR_GPIO_P5) ? 0x2 : 0;
 
            // Register interrupts on both GPIO pins
            twr_exti_register(TWR_EXTI_LINE_P4, TWR_EXTI_EDGE_RISING_AND_FALLING, _twr_module_encoder_exti_handler, NULL);
            twr_exti_register(TWR_EXTI_LINE_P5, TWR_EXTI_EDGE_RISING_AND_FALLING, _twr_module_encoder_exti_handler, NULL);
 
            _twr_module_encoder.initialized = true;
        }
        else
        {
            if (_twr_module_encoder.event_handler != NULL)
            {
                _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_ERROR, _twr_module_encoder.event_param);
            }
        }
    }
}
 
static void _twr_module_encoder_exti_handler(twr_exti_line_t line, void *param)
{
    (void) line;
    (void) param;
 
    // Read current GPIO state
    _twr_module_encoder.samples <<= 2;
    _twr_module_encoder.samples |= twr_gpio_get_input(TWR_GPIO_P4) ? 0x1 : 0;
    _twr_module_encoder.samples |= twr_gpio_get_input(TWR_GPIO_P5) ? 0x2 : 0;
    _twr_module_encoder.samples &= 0xf;
 
    if (_twr_module_encoder.samples == 0x7)
    {
        _twr_module_encoder.increment--;
 
        twr_scheduler_plan_now(_twr_module_encoder.task_id);
    }
    else if (_twr_module_encoder.samples == 0xd)
    {
        _twr_module_encoder.increment++;
 
        twr_scheduler_plan_now(_twr_module_encoder.task_id);
    }
}
 
static void _twr_module_encoder_button_event_handler(twr_button_t *self, twr_button_event_t event, void *event_param)
{
    (void) self;
    (void) event_param;
 
    if (_twr_module_encoder.event_handler == NULL)
    {
        return;
    }
 
    if (event == TWR_BUTTON_EVENT_PRESS)
    {
        _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_PRESS, _twr_module_encoder.event_param);
    }
    else if (event == TWR_BUTTON_EVENT_RELEASE)
    {
        _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_RELEASE, _twr_module_encoder.event_param);
    }
    else if (event == TWR_BUTTON_EVENT_CLICK)
    {
        _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_CLICK, _twr_module_encoder.event_param);
    }
    else if (event == TWR_BUTTON_EVENT_HOLD)
    {
        _twr_module_encoder.event_handler(TWR_MODULE_ENCODER_EVENT_HOLD, _twr_module_encoder.event_param);
    }
}
 
static bool _twr_module_encoder_test_pin(twr_gpio_channel_t channel)
{
    twr_gpio_set_mode(channel, TWR_GPIO_MODE_OUTPUT);
 
    twr_gpio_set_output(channel, 1);
 
    twr_gpio_set_pull(channel, TWR_GPIO_PULL_DOWN);
 
    twr_gpio_set_mode(channel, TWR_GPIO_MODE_INPUT);
 
    twr_timer_start();
 
    twr_timer_delay(20);
 
    twr_timer_stop();
 
    int value = twr_gpio_get_input(channel);
 
    twr_gpio_set_mode(channel, TWR_GPIO_MODE_ANALOG);
 
    twr_gpio_set_pull(channel, TWR_GPIO_PULL_NONE);
 
    return value != 0;
}
 
static bool _twr_module_encoder_present_test(void)
{
    twr_system_pll_enable();
 
    twr_timer_init();
 
    twr_gpio_init(TWR_GPIO_P4);
 
    twr_gpio_init(TWR_GPIO_P5);
 
    bool is_present = _twr_module_encoder_test_pin(TWR_GPIO_P4) && _twr_module_encoder_test_pin(TWR_GPIO_P5);
 
    twr_system_pll_disable();
 
    return is_present;
}