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Tick/IRQ driven ADCs for TCC780x. Solves the weird button behaviour mentioned on the D2 wiki page.

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16974 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Rob Purchase 2008-04-04 23:43:31 +00:00
parent 32bd0f8ab1
commit 36f8fba209
2 changed files with 53 additions and 23 deletions
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75
firmware/target/arm/tcc780x/adc-tcc780x.c
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@ -24,20 +24,46 @@
#include "string.h"
#include "adc.h"
/*
TODO: We probably want to do this on the timer interrupt once we get
interrupts going - see the sh-adc.c implementation for an example which
looks like it should work well with the TCC77x.
Also, this code is practically identical between 77x & 780x targets.
Should probably find a common location to avoid the duplication.
*/
static unsigned short adcdata[8];
static void adc_do_read(void)
#ifndef BOOTLOADER
/* Tick task */
static void adc_tick(void)
{
int i;
PCLK_ADC |= PCK_EN; /* Enable ADC clock */
/* Start converting the first 4 channels */
for (i = 0; i < 4; i++)
ADCCON = i;
}
/* IRQ handler */
void ADC(void)
{
int num;
uint32_t adc_status;
do
{
adc_status = ADCSTATUS;
num = (adc_status>>24) & 7;
if (num) adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
} while (num);
PCLK_ADC &= ~PCK_EN; /* Disable ADC clock */
}
#endif /* BOOTLOADER */
unsigned short adc_read(int channel)
{
#ifdef BOOTLOADER
/* IRQs aren't enabled in the bootloader - just do the read directly */
int i,num;
uint32_t adc_status;
PCLK_ADC |= PCK_EN; /* Enable ADC clock */
@ -49,20 +75,15 @@ static void adc_do_read(void)
/* Wait for data to become stable */
while ((ADCDATA & 0x1) == 0);
/* Now read the values back */
for (i=0;i < 4; i++) {
do
{
adc_status = ADCSTATUS;
adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
}
num = (adc_status>>24) & 7;
if (num) adcdata[(adc_status >> 16) & 0x7] = adc_status & 0x3ff;
} while (num);
PCLK_ADC &= ~PCK_EN; /* Disable ADC clock */
}
unsigned short adc_read(int channel)
{
/* Either move this to an interrupt routine, or only perform the read if
the last call was X length of time ago. */
adc_do_read();
#endif
return adcdata[channel];
}
@ -71,6 +92,14 @@ void adc_init(void)
{
/* consider configuring PCK_ADC source here */
ADCCON = (1<<4); /* Leave standby mode */
ADCCFG |= 0x00000003; /* Single-mode, auto power-down */
ADCCON = (1<<4); /* Enter standby mode */
ADCCFG |= 0x0000000B; /* Single-mode, auto power-down, IRQ enable */
#ifndef BOOTLOADER
IEN |= ADC_IRQ_MASK; /* Enable ADC IRQs */
tick_add_task(adc_tick);
sleep(2); /* Ensure valid readings when adc_init returns */
#endif
}