fix(PeriphDrivers): Fix Stuck Timer When PWM is set to 0

[ozersa]

Pull Request Template

Description

For PWM mode when timer period end the tmr->count is reset to 0x00000001 and the timer resumes counting.
On edge case (pwm==0) flow stuck in while loop, tmr->cnt newer become bigger than pwm so that +8 added.

Checklist Before Requesting Review

• PR Title follows correct guidelines.
• Description of changes and all other relevant information.
• (Optional) Link any related GitHub issues using a keyword
• (Optional) Provide info on any relevant functional testing/validation. For API changes or significant features, this is not optional.

Test detail

If tolerance value be +8

If tolerance value be +2

As can be seen below due to if checks it is hard to catch exact 0x000001 value, there should be a tolerance value, so that i set it as 8 (TMR clock is PCLK, prescaler=1)

[Jake-Carter]

@ozersa What about monitoring the interrupt flag set by the hardware?

We only need to do this check if the timer is currently running. Something like:

int MXC_TMR_RevB_SetPWM(mxc_tmr_revb_regs_t *tmr, uint32_t pwm)
{
    int tmr_id = MXC_TMR_GET_IDX((mxc_tmr_regs_t *)tmr);
    (void)tmr_id;
    MXC_ASSERT(tmr_id >= 0);

    if (pwm > (tmr->cmp)) {
        return E_BAD_PARAM;
    }

    bool timera_is_running = tmr->ctrl0 & MXC_F_TMR_CTRL0_EN_A;
    bool timerb_is_running = tmr->ctrl0 & MXC_F_TMR_CTRL0_EN_B;

    if (timera_is_running || timerb_is_running) {
        MXC_TMR_RevB_ClearFlags(tmr); // Clear flags so we can catch the next one
        while (!MXC_TMR_RevB_GetFlags(tmr)) {} // Wait for next PWM transition
        MXC_TMR_RevB_Stop(tmr); // Pause timer
        MXC_TMR_RevB_SetCount(tmr, 0); // Reset the count
        MXC_TMR_RevB_ClearFlags(tmr); // Clear flags since app code wants the new PWM transitions set by this function
    }

    tmr->pwm = pwm;
    while (!(tmr->intfl & MXC_F_TMR_REVB_INTFL_WRDONE_A)) {}

    if (timera_is_running) {
        tmr->ctrl0 |= MXC_F_TMR_REVB_CTRL0_EN_A; // Unpause A
    }

    if (timerb_is_running) {
        tmr->ctrl0 |= MXC_F_TMR_REVB_CTRL0_EN_B; // Unpause B
    }

    return E_NO_ERROR;
}

[ozersa]

The solution works.
Commit updated.