//-------------------------------------------------------------------
// Filename: hal_clock.c
// Description: This file defines clock related functions for the CC253x family
//              of RF system-on-chips from Texas Instruments.
//-------------------------------------------------------------------
//-------------------------------------------------------------------
// INCLUDES
//-------------------------------------------------------------------
#include "hal_defs.h"
#include "hal_clock.h"

//-------------------------------------------------------------------
// PUBLIC FUNCTIONS
//-------------------------------------------------------------------
//-------------------------------------------------------------------
// @fn  clockSetMainSrc
// @brief  Function for setting the main system clock source.
//         The function turns off the clock source that is not being used.
//        TICKSPD is set to the same frequency as the source.
// @param  uint8 source (one of CLOCK_SRC_HFRC or CLOCK_SRC_XOSC)
// @return void
//-------------------------------------------------------------------
void clockSetMainSrc(uint8 source)
{
    register uint8 osc32k_bm = CLKCONCMD &CLKCON_OSC32K_BM;

    // Source can have the following values:
    // CLOCK_SRC_XOSC   0x00  High speed Crystal Oscillator (XOSC)
    // CLOCK_SRC_HFRC   0x01  Low power RC Oscillator (HFRC)

    SLEEPCMD &= ~SLEEP_OSC_PD_BM; // power up both oscillators
    while (!CC2530_IS_HFRC_STABLE() || ((SLEEPSTA &SLEEP_OSC_PD_BM) != 0))
        ;
    // wait until the oscillator is stable
    NOP();

    if (source == CLOCK_SRC_HFRC)
    {
        CLKCONCMD = (osc32k_bm | CLKCON_OSC_BM | TICKSPD_DIV_2 | CLKCON_CLKSPD_BM);
    }
    else if (source == CLOCK_SRC_XOSC)
    {
        CLKCONCMD = (osc32k_bm | TICKSPD_DIV_1);
    }
    CC2530_WAIT_CLK_UPDATE();
    SLEEPCMD |= SLEEP_OSC_PD_BM; // power down the unused oscillator
}

//-------------------------------------------------------------------
// @fn  clockSelect32k
// @brief  Function for selecting source for the 32kHz oscillator
// @param  uint8 source (one of CLOCK_32K_XTAL or CLOCK_32K_RCOSC)
// @return uint8 - SUCCESS or FAILED
//-------------------------------------------------------------------
uint8 clockSelect32k(uint8 source)
{
    // System clock source must be high frequency RC oscillator before
    // changing 32K source. 
    if (!(CLKCONSTA &CLKCON_OSC_BM))
    {
        return FAILED;
    }

    if (source == CLOCK_32K_XTAL)
    {
        CLKCONCMD &= ~CLKCON_OSC32K_BM;
    }
    else if (source == CLOCK_32K_RCOSC)
    {
        CLKCONCMD |= CLKCON_OSC32K_BM;
    }
    CC2530_WAIT_CLK_UPDATE();

    return SUCCESS;
}