timer_dspic33c.c

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/**
 * @file timer_dspic33c.c
 * @author Sebastien CAUX (sebcaux)
 * @copyright UniSwarm 2018-2020
 *
 * @date June 01, 2018, 05:28 PM
 *
 * @brief Timer support for udevkit dsPIC33CH, dsPIC33CK
 *
 * Implementation based on Microchip document DS70005279B :
 *  http://ww1.microchip.com/downloads/en/DeviceDoc/dsPIC33-PIC24-FRM-Timer1-Module-70005279B.pdf
 */

#include "timer.h"

#include <driver/sysclock.h>
#include <archi.h>

#if !defined (TIMER_COUNT) || TIMER_COUNT==0
  #warning "No timer on the current device or unknow device"
#endif

#define TIMER_FLAG_UNUSED  0x00
typedef struct {
    union {
        struct {
            unsigned used : 1;
            unsigned enabled : 1;
            unsigned bit32 : 1;
            unsigned : 5;
        };
        uint8_t val;
    };
} timer_status;

struct timer_dev
{
    uint32_t periodUs;
    timer_status flags;
    void (*handler)(void);
};

struct timer_dev timers[] = {
#if TIMER_COUNT>=1
    {
        .periodUs = 0,
        .flags = {{.val = TIMER_FLAG_UNUSED}},
        .handler = NULL
    },
#endif
};

/**
 * @brief Gives a free timer device number
 * @return timer device number
 */
rt_dev_t timer_getFreeDevice()
{
#if TIMER_COUNT>=1
    uint8_t i;
    rt_dev_t device;

    for (i = 0; i < TIMER_COUNT; i++)
    {
        if (timers[i].flags.used == 0)
        {
            break;
        }
    }

    if (i == TIMER_COUNT)
    {
        return NULLDEV;
    }
    device = MKDEV(DEV_CLASS_TIMER, i);

    timer_open(device);

    return device;
#else
    return NULLDEV;
#endif
}

/**
 * @brief Open a timer
 * @param device timer device number
 */
int timer_open(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }
    if (timers[timer].flags.used == 1)
    {
        return -1;
    }

    timers[timer].flags.used = 1;
    timers[timer].handler = NULL;

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Close a timer
 * @param device timer device number
 */
int timer_close(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timer_disable(device);

    timers[timer].flags.val = TIMER_FLAG_UNUSED;

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Enable the specified timer device
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
int timer_enable(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timers[timer].flags.enabled = 1;

    switch (timer)
    {
    case 0:
        T1CONbits.TON = 1;  // enable timer module
        _T1IF = 0;
        if (timers[0].handler)
        {
            _T1IE = 1;
        }
        else
        {
            _T1IE = 0;
        }
        _T1IP = 1;
        break;
    }

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Disable the specified timer device
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
int timer_disable(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timers[timer].flags.enabled = 0;

    switch (timer)
    {
    case 0:
        T1CONbits.TON = 0;  // disable timer module
        _T1IE = 0;
        break;
    }

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Sets the handler function that will be called on timer interrupt
 * @param device timer device number
 * @param handler void funtion pointer or null to remove the handler
 * @return 0 if ok, -1 in case of error
 */
int timer_setHandler(rt_dev_t device, void (*handler)(void))
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timers[timer].handler = handler;
    timer_enable(device);

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Sets the internal period
 * @param device timer device number
 * @param prvalue reset value of timer, does not consider the time
 * @return 0 if ok, -1 in case of error
 */
int timer_setPeriod(rt_dev_t device, uint32_t prvalue)
{
#if TIMER_COUNT>=1
    uint8_t div = 0;
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    if (prvalue > 65535)
    {
        div = 0b01; // 8 divider
        prvalue >>= 3;
        if (prvalue > 65535)
        {
            div = 0b11; // 256 divider
            prvalue >>= 5;
            if (prvalue > 65535)
            {
                prvalue = 65535;
            }
        }
    }

    switch (timer)
    {
    case 0:
        T1CONbits.TCKPS = div;   // set divide number
        PR1 = prvalue;           // pr value, comparator value
        break;
    }

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Gets the internal period
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
uint32_t timer_period(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    switch (timer)
    {
    case 0:
        return PR1;
    }
    return -1;
#else
    return -1;
#endif
}

/**
 * @brief Sets the period in us of the timer module to work in timer mode
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
int timer_setPeriodMs(rt_dev_t device, uint32_t periodMs)
{
#if TIMER_COUNT>=1
    uint32_t prvalue;
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timers[timer].periodUs = periodMs * 1000;

    prvalue = sysclock_periphFreq(SYSCLOCK_CLOCK_TIMER) / 1000 * periodMs;
    timer_setPeriod(device, prvalue);

    return 0;
#else
    return -1;
#endif
}

/**
 * @brief Sets the period in us of the timer module to work in timer mode
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
int timer_setPeriodUs(rt_dev_t device, uint32_t periodUs)
{
#if TIMER_COUNT>=1
    float prvalue;
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    timers[timer].periodUs = periodUs;

    prvalue = (float)sysclock_periphFreq(SYSCLOCK_CLOCK_TIMER) / 1000000.0 * (float)periodUs;

    return timer_setPeriod(device, (uint32_t)prvalue);
#else
    return -1;
#endif
}

/**
 * @brief Returns the current period in us
 * @param device timer device number
 * @return period in us if ok, 0 in case of error
 */
uint32_t timer_periodUs(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return 0;
    }

    return timers[timer].periodUs;
#else
    return 0;
#endif
}

/**
 * @brief Returns the current period in us
 * @param device timer device number
 * @return period in us if ok, 0 in case of error
 */
uint32_t timer_periodMs(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return 0;
    }

    return timers[timer].periodUs / 1000;
#else
    return 0;
#endif
}

/**
 * @brief Returns the current value of timer
 * @param device timer device number
 * @return value if ok, 0 in case of error
 */
uint16_t timer_getValue(rt_dev_t device)
{
#if TIMER_COUNT>=1
    uint16_t value;
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return 0;
    }

    switch (timer)
    {
    case 0:
        value = TMR1;
        break;
    }

    return value;
#else
    return 0;
#endif
}

/**
 * @brief Sets the current value of timer
 * @param device timer device number
 * @return 0 if ok, -1 in case of error
 */
int timer_setValue(rt_dev_t device, uint16_t value)
{
#if TIMER_COUNT>=1
    uint8_t timer = MINOR(device);
    if (timer >= TIMER_COUNT)
    {
        return -1;
    }

    switch (timer)
    {
    case 0:
        TMR1 = value;
        break;
    }

    return 0;
#else
    return -1;
#endif
}

#if TIMER_COUNT>=1
void __attribute__ ((interrupt, no_auto_psv)) _T1Interrupt()
{
    if (timers[0].handler)
    {
        (*timers[0].handler)();
    }

    _T1IF = 0;
}
#endif

/*
void timer_reconfig()
{
    uint8_t i;
    rt_dev_t device;

    for (i = 0; i < TIMER_COUNT; i++)
    {
        if (timers[i].flags.used == 1)
        {
            device = MKDEV(DEV_CLASS_TIMER, i);
            timer_setPeriodMs(device, timers[i].periodMs);
        }
    }
}
*/