hal.c

来自「蓝牙耳机软件源代码」· C语言 代码 · 共 80 行

/*
  Rather small Hardware Abstraction Layer (HAL) for headset
*/
#include "hal.h"

#include <codec.h>
#include <pio.h>


/* TODO tidy this up once the new traps are supported by the firmware */



/* Scale the supplied gain to be within the specified range */
static uint16 scaleGainToRange(uint8 gain, uint16 max_range, uint16 max_gain)
{
    return (((((gain * 10) * max_range)/max_gain) + 5)/10);
}


/*
    HALsetVolume

    Set the headset speaker volume.
*/
void HALsetVolume(uint8 vol)
{
    uint16 scaled_val = 0;
    
    /* Get the range supported by the codec */
    uint16 range = CodecOutputGainRange() - 1;
    
    /* If the range is zero don't bother setting anything */
    if (!range)
        return;
        
    /* If the range is not zero scale the gain to be in that range */
    scaled_val = scaleGainToRange(vol, range, 15);
        
    /* Set the codec gain */
    CodecSetOutputGain(scaled_val);
}


/*
    HALsetLED 

    Set the state of an LED.  For this example the leds are just
    mapped directly to PIO lines.
*/
/*lint -esym(759, HALsetLED) -esym(765,HALsetLED) -esym(714,HALsetLED) */
void HALsetLED(uint8 bit, uint8 state)
{
    PioSet(bit, bit*state);
}


/*
    HALsetMicrophone
    
    Set the headset microphone gain.
*/
void HALsetMicrophone(uint8 gain)
{
    uint16 scaled_val = 0;

    /* Get the range supported by the codec */
    uint16 range = CodecInputGainRange() - 1;

    /* If the range is zero don't bother setting anything */
    if (!range)
        return;

    /* If the range is not zero scale the gain to be in that range */
    scaled_val = scaleGainToRange(gain, range, 15);

    /* Set the codec gain */
    CodecSetInputGain(scaled_val);
}